[U.S. Department of Energy First Annual Report on Nuclear Non-Proliferation : Supplement to Annual Report to Congress]
[From the U.S. Government Publishing Office, www.gpo.gov]

E l.l : yrt/SUpp.
DOE/PE-0014/R1
U. S. DEPOSITORY DOCUMENT JUN 9 1980
CONNECTICUT COLLEGE LIBRARY NEW LONDON. CT 06320
First Annual Report on Nuclear Non-Proliferation
Supplement to Annual Report to Congress
U.S. Department of Energy Office of Policy and Evaluation
FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS U.S. GOVERNMENT PRINTING OFFICE WASHINGTON, D.C. 20404
1979
All references to years refer to fiscal years unless otherwise noted.
DOE/PE-0014/R1
First Annual Report on Nuclear Non-Proliferation
Supplement to Annual Report to Congress
U.S. Department of Energy Office of Policy and Evaluation Washington, D.C. 20585
Preface
This First Annual Report on Nuclear Non-Proliferation is a supplement to and integral part of the first DOE Annual Report to Congress (DOE/PE-0014), transmitted to The President by the Secretary of Energy in 1979.
This document is submitted to Congress in accordance with the requirements of section 602 of the Nuclear Non-Proliferation Act of 1978.
Table of Contents
Page
Preface......................................................... iii
Chapter 1. Nuclear Non-Proliferation Activities........................... 1
Overview...................................................... 1
Agreements for Cooperation.................................... 2
Technical Exchange............................................ 2
Introduction................................................ 2
Views and Recommendations................................... 3
The United States as a Reliable Supplier of Nuclear Fuels.	3
Bilateral Fuel Supply....................................... 3
Multilateral Arrangements................................... 4
International Nuclear Fuel Bank............................... 4
Interim United States Stockpile............................. 4
Views and Recommendations................................... 4
Implementation of United States Non-Proliferation Policy..	4
Export Controls............................................. 4
DOE Technology Controls..................................... 5
Subsequent Arrangements....................................... 6
Introduction................................................ 6
Views and Recommendations................................... 6
Classification................................................ 6
Introduction................................................ 6
Views and Recommendations................................... 7
Cooperation in Strengthening International Safeguards and
Physical Security........................................... 7
Introduction................................................ 7
Views and Recommendations................................... 8
The U.S.-IAEA “Voluntary Offer” Safeguards Agreements.....	8
Introduction................................................ 8
Views and Recommendations................................... 8
United States Spent Fuel Storage Policy....................... 8
Introduction................................................ 8
Views and Recommendations................................... 9
Development of Proliferation-Resistant Fuel Cycle Technologies	9
Introduction..........♦..................................... 9
Views and Recommendations.................................. 10
International Nuclear Fuel Cycle Evaluation.................. 10
v
Chapter	Page
2.	Proliferation Implications of Nuclear Systems................. 13
Scope and Approach............................................ 13
Perspective on the Proliferation Resistance of Enrichment
Technologies................................................ 14
Techniques Used Presently................................... 14
Advanced Techniques......................................... 16
Proliferation Vulnerabilities of Reprocessing of Spent Fuel..	18
Techniques Used Presently................................... 18
Alternative Techniques...................................... 18
Proliferation-Resistance Assessments of Fuel Cycle Systems ...	19
Once-through Systems........................................ 19
Thermal Recycle Systems..................................... 22
Fast-Breeder Systems........................................ 24
Research Reactors............................................. 28
Proliferation Resistance.................................... 28
Efforts to Improve the Proliferation Resistance of Research Reactors..................................................   29
List of Tables
Table No.	Page
1.	Proliferation resistance assessment methodology........ 15
2.	Definitions of assessment factors..................... 15
3.	List of Acronyms...........*.......................... 31
vi
Chapter 1
Nuclear Non-Proliferation
Activities
Overview
Section 602 of the Nuclear Non-Proliferation Act of 1978 (NNPA), requires that DOE’s Annual Report include views and recommendations regarding non-proliferation policies and actions for which the Department is responsible. The Act also requires a detailed analysis of the proliferation implications of advanced enrichment and reprocessing techniques, advanced reactors, and alternative fuel cycles, including an unclassified summary and a comprehensive version containing relevant classified information.
The goals of United States non-proliferation policy are to minimize the spread of nuclear weapons and to create a stable international environment for the peaceful use of nuclear energy. The achievement of these goals entails four interrelated efforts:
1.	Urging adherence to the Nuclear Non-Proliferation Treaty and the Treaty for the Prohibition of Nuclear Weapons in Latin America, and encouraging the wider application and technical improve
ment of International Atomic Energy Agency (IAEA) safeguards.
2.	Working to deter the spread of sensitive nuclear facilities, such as reprocessing and enrichment plants, and the accumulation of nuclear materials directly usable in the manufacture of nuclear explosives.
3.	Promoting cooperation in establishing additional spent fuel storage capacity as an attractive alternative to premature reprocessing.
4.	Remaining a stable, reliable, and attractive supplier of nonsensitive nuclear materials to other countries.
DOE plays a central role in promoting these goals. Under the Atomic Energy Act of 1954, as amended, and the NNPA, the Department has a number of responsibilities, including:
1.	Participating, under the leadership of the Department of State, in negotiating agreements for cooperation with foreign nations in the peaceful use of nuclear energy.
2.	Joining other agencies to reach an executive branch judgment regarding the issuance of export licenses by the Nuclear Regulatory Commission.
1
3.	Leading other agencies of the executive branch in reaching decisions on subsequent arrangements pursuant to agreements for cooperation, and in controlling nuclear technology exports under 10CFR810.
4.	Distributing and controlling of special nuclear equipment and materials.
5.	Participating in bilaterial and multilateral cooperation with foreign nations and organizations to promote the peaceful use of nuclear energy.
Agreements for Cooperation
The NNPA requires DOE to provide technical assistance and concurrence in renegotiating agreements for cooperation in the peaceful uses of atomic energy. Following the passage of this act, DOE and the Department of State, in consultation with the Arms Control and Disarmament Agency (ACDA), developed a model agreement or draft based on the requirements of NNPA which, modified as appropriate to accommodate the individual programs and policies of cooperating countries, serves as the basis for these negotiations. In addition to the IAEA and the nine-member European Atomic Energy Community (Euratom), almost all countries affected have indicated their willingness to discuss renegotiation of existing agreements.
DOE joins the Department of State in planning and conducting negotiations. Upon completion, any proposed agreements or amendments must be jointly recommended by the Secretaries of State and Energy to the President for his approval, along with an unclassified Nuclear Proliferation Assessment Statement prepared by ACDA. As of the end of 1978, negotiations or preliminary discussions were held with sixteen individual countries, the IAEA, and Euratom.
Technical Exchange
Introduction
Technical cooperation with other nations in the peaceful uses of nuclear energy falls into several categories. Activities undertaken in the
International Nuclear Fuel Cycle Evaluation (INFCE) are described elsewhere in this chapter. Bilateral technical exchanges take place under the provisions of agreements for cooperation and technical exchange agreements. Technical exchange agreements provide for mutual transfers of technical information, visits by personnel, and collaboration in mutually agreed-upon projects. Implementation also proceeds by mutual agreement.
DOE’s technical exchanges are designed to:
1.	Share the benefits of nonsensitive peaceful nuclear technology with other countries, thereby assisting them in meeting their energy supply needs.
2.	Increase the technology base and rate of progress of the United States nuclear program.
3.	Provide a common international technical understanding of nuclear power systems so that resource utilization, nonproliferation, physical security, health, safety, and regulation concerns may be resolved in mutually satisfactory ways.
4.	Acquaint other countries with the benefits of United States technology, thereby promoting development of United States export markets under effective safeguards and control.
At the present time, the United States has technical exchange agreements on reactor development with Canada, Euratom, the Federal Republic of Germany, France, Japan, the United Kingdom, and the Soviet Union.
The United States has endeavored to foster cooperation in the development of more proliferation-resistant fuel cycle alternatives in INFCE, and has also promoted this objective in its bilateral dealings. Examples of adjustments to existing or proposed bilateral exchange agreements are modification during 1978 to DOE’s liquid metal fast-breeder reactor (LMFBR) agreement with the United Kingdom and modification of a similar agreement under negotiation with Japan. Both modifications reflect a joint recognition of the dangers posed by the proliferation of nuclear weapons technology, of weapons-usable facilities, and of materials; and further exhibit mutual interest in exploring alternative breeder fuel cycles that may offer more non-proliferation advantages.
2
Similar changes have been made since April 1972 in other bilateral exchanges.
Canada, the Federal Republic of Germany, and Sweden have specific bilateral technical exchange agreements with DOE in radioactive waste management. In addition, DOE’s liquid metal fast breeder reactor exchange agreement with the United Kingdom provides for possible cooperation in nuclear waste management. As is the case with exchanges in reactor development and implementing activities, DOE has proposed modifications to reflect non-proliferation priorities. In keeping with the desire to focus on alternatives to conventional reprocessing, emphasis is being given to extended storage of unreprocessed spent fuels. Information is not being transferred in aspects of waste technology that contribute either to reprocessing capability or to its encouragement.
The IAEA is a major channel for multilateral cooperation with other countries in the peaceful uses of nuclear energy. The main objectives of the agency’s technical assistance program are to promote the transfer of skills and knowledge relating to the peaceful uses of nuclear energy and to aid recipient countries in carrying out their atomic energy activities more efficiently and safely. In 1978, the total United States voluntary contribution included $1.7 million in cash and $8.25 million in goods and services, of which $5.6 million was devoted to safeguards. This country also paid a regular assessment of $12.4 million to the IAEA.
To promote United States non-proliferation objectives through the IAEA, a new voluntary offer of technical assistance has been made. Subject to the approval of Congress, an interagency group (ACDA, DOE and DOS) will first establish a trust program that would authorize up to $1 million per year for 5 years, funds exclusively reserved for nuclear assistance to developing countries that are party to the Nuclear Non-Proliferation Treaty (NPT). The offer of technical assistance would involve an additional $1 million per year for 5 years to provide low enriched uranium fuel (rather than highly enriched uranium) for research reactors; these funds would be allocated on a preferential basis to developing countries that are party to the NPT. There is also an additional provision of up to $1 million per year for 5 years in fuel cycle services for research reactors. The principal
focus is fuel fabrication services where it would assist countries in the use of lower enrichment levels in research reactors.
Views and Recommendations
Since the passage of the Atomic Energy Act of 1954, the United States has engaged in technical exchange and cooperation to promote the development of its own nuclear energy programs at lower cost and to further the peaceful uses of nuclear energy abroad through international arrangements. The emergence of new generations of nuclear technology, the need to find more proliferation-resistant solutions to the problems raised by these technologies, and the increasing number of nations intent on resorting to nuclear energy to meet national needs make these objectives more important than in the past. DOE has recommended that the United States continue to support bilateral exchanges with nations willing to accept appropriate non-proliferation obligations and to offer expanded technical assistance through the IAEA under similar terms and conditions.
The United States as a Reliable Supplier of Nuclear Fuels
An essential component of U.S. nonproliferation policy is the reinforcement of the country’s credibility as a reliable and attractive supplier of nuclear- fuel and equipment to nations complying with non-proliferation conditions. Recognizing that a single mechanism will not serve in all circumstances, the United States has been examining a number of approaches.
Bilateral Fuel Supply
In April 1977, the President announced his decision to construct a new enrichment plant at Portsmouth, Ohio. The first year of substantial production will be 1988.
In 1978, DOE issued a new contract to provide both foreign and domestic customers more attractive terms for purchasing enrichment services. DOE also announced that it will sell or
3
loan natural uranium to its enrichment services customers to meet an unforeseen emergency in which all attempts have been unsuccessful in procuring natural uranium from commercial sources.
To provide for a more expeditious export licensing process, the executive branch and the Nuclear Regulatory Commission put into effect export review procedures. These were designed to facilitate the processing of licenses for the export of nuclear fuel.
Multilateral Arrangements
In cooperation with other supplier nations, the United States seeks to develop measures to increase secure access to adequate and timely nuclear fuel supplies for buyers prepared to accept adequate non-proliferation commitments. This country is participating in an INFCE evaluation of possible measures for improving fuel assurances, including pooling of fuel resources on a reciprocal guarantee basis, improved coordination in planning for new fuel production facilities, and improved cooperation in uranium exploration.
International Nuclear Fuel Bank
In his speech inaugurating INFCE in October 1977, the President endorsed the concept of an International Nuclear Fuel Bank to protect consumer states that suffer interruptions in their contracted fuel supply for reasons unrelated to compliance with their non-proliferation obligations. The President indicated United States readiness to make a substantial contribution to such a bank. DOE and DOS are now in the process of exploring this concept within INFCE as well as on a bilateral basis with other countries.
Interim United States Stockpile
Pursuant to section 104b of the NNPA, a report was prepared during 1978 for the President to submit to Congress. This report concluded that the United States should consider the establish
ment of an interim stockpile not exceeding 5 million separate work units (SWU). This stockpile might serve several purposes.
First, an appropriate portion of the stockpile could be provided to the International Nuclear Fuel Bank. Second, the United States could also make this material available (under appropriate supply arrangement) to cooperating countries that suffer a serious or unusual interruption in their contracted fuel supplies for reasons unrelated to their non-proliferation obligations. The interim United States stockpile could thus serve the same purposes as the bank until the bank is established. Also, the U.S. could consider transferring material from the stockpile when such action would further fuel assurance objectives.
Along with other agencies, DOE is now conducting an in-depth examination of such stockpiling, including the appropriate composition, costs, payment, legislative requirements, and the efficacy of detailed stockpile policies and programs in promoting domestic non-proliferation policies.
Views and Recommendations
A number of steps and activities are recommended. The United States should proceed to assess the utility of establishing an interim stockpile and should continue to pursue consultations with other nations on the International Nuclear Fuel Bank. Also, the country should be prepared to consider, and possibly participate in, additional fuel assurance measures that may be proposed as a result of INFCE. Efforts further need to be made to implement the procedures and provisions of the United States export licensing process so that nations abiding by their non-proliferation obligations can be assured that their fuel needs will be met on a timely and reliable basis.
Implementation of United States Non-Proliferation Policy
Export Controls
To implement export controls pursuant to the NNPA, the Departments of Energy, State,
4
Defense, Commerce and the Arms Control and Disarmament Agency (ACDA) developed procedures for reviewing all exports of nuclear material and equipment licensed by the Nuclear Regulatory Commission (NRC) and the Department of Commerce. These interagency review procedures apply to subsequent arrangements involving nuclear materials, and also to exports of nuclear technology subject to DOE control. Difficult and complex cases raising policy questions are referred to a Subgroup on Nuclear Export Coordination (SNEC), a working committee of the senior level National Security Council Ad Hoc Group on Nuclear Non-Proliferation established pursuant to the NNPA. Additional steps taken leading to tighter export controls include the preparation of updated lists of items that may be of significance for nuclear explosive purposes.
DOE is reviewing several thousand nuclear export cases annually, and over 100 cases have been referred to SNEC. Concerned agencies are working to ensure that the statutory time limits of review are met and to expedite procedures for handling cases of limited non-proliferation concern.
DOE Technology Controls
Section 57.b. of the Atomic Energy Act of 1954, as amended, prohibits any person (as defined in section 11 of the Act) from directly or indirectly engaging in the production of special nuclear material outside the United States except (1) under an agreement for cooperation made pursuant to section 123, including a specific authorization in a subsequent arrangement under section 131 of this Act, or (2) upon authorization by the Secretary of Energy after a determination that such activity will not be inimical to the interest of the United States. The Nuclear Non-Proliferation Act of 1978 mandated the establishment of formalized procedures for the review of such cases and also provided that a non-inimical determination by the Secretary could only be made with the concurrence of the Department of State and after consultation with the Arms Control and Disarmament Agency, the Departments of Commerce and Defense and the Nuclear Regulatory Commission. Formalized procedures were developed
and published in the Federal Register in June 1978.
The prohibition of the Act extends to activities associated with the furnishing of plant and equipment as well as the furnishing of nuclear energy-related information to foreign recipients or for use abroad.
DOE’s regulation 10 CFR 810 implements section 57.b.(2) of the Act. Under these regulations the following activities are generally authorized to be conducted anywhere outside the United States, provided they do not involve the communication of Restricted Data or other classified defense information, and are not in violation of other provisions of law:
1.	The furnishing of information that is available to the public in published form.
2.	Participation in meetings or conferences sponsored by educational institutions, laboratories, scientific or technical organizations.
3.	International conferences held under the auspices of a nation or group of nations.
4.	Exchange programs approved by the Department of State.
These are the only activities that are generally authorized for conduct in Sino-Soviet bloc countries. In Free World countries, section 810 provides an additional general authorization for the conduct of activities not already generally authorized as stated above, provided they do not constitute engaging directly or indirectly in activities pertaining to the design, construction, fabrication, or operation of facilities for the:
1.	Chemical processing of irradiated special nuclear material.
2.	The production of heavy water.
3.	The separation of isotopes of source or special nuclear material.
4.	The fabrication of nuclear fuel containing plutonium, or equipment or components especially designed for, modified or adapted for use in any of the foregoing.
5.	Training foreign personnel in any of the foregoing activities.
6.	Furnishing information not available to the public in published form for use in the foregoing activities.
The general authorization for Free World countries is interpreted to include the export of
5
civilian nuclear power reactor technology; fuel fabrication technology (excluding fuel containing plutonium); technology relating to uranium milling, mining and conversion; and waste management technology.
Any activity not under the purview of 10 CFR 810 must be approved by the Secretary of Energy.
In 1978, DOE processed approximately twenty-five section 810 cases, an increase of seven over 1977. The number of inquiries received from United States companies as to the applicability of 10 CFR 810 to a proposed activity also increased during the year.
Subsequent Arrangements
Introduction
Under the provisions of the NNPA, DOE leads the review of subsequent arrangements, a term referring to arrangements entered into by an agency or department of the United States Government with respect to nuclear cooperation with other nations or group of nations as defined by section 303 of the Nuclear Non-Proliferation Act of 1978. This review requires the concurrence of the Department of State and consultations with the Departments of Commerce and Defense, the ACDA and the NRC. The issues involved in the review of subsequent arrangements include:
1.	Contracts for the furnishing of nuclear materials and equipment.
2.	Approvals for transfer by a recipient of any source or special nuclear material, production or utilization facility, or nuclear technology for which prior approval is required under an agreement for cooperation.
3.	Authorization for the distribution of nuclear materials and equipment pursuant to the provisions of the NNPA.
4.	Arrangements for physical security.
5.	Arrangements for the application of safeguards with respect to nuclear material and equipment.
6.	Any other arrangement that the Department determines to be important to prevent proliferation.
With respect to retransfers of United States-origin material for purposes of reprocessing, requests are considered only on a case-by-case basis. During the period of INFCE, requests can be approved if the requirements of section 131b of the NNPA are met, if there is a clear showing of need (such as physical congestion), and if the requesting country has made appropriate efforts to expand its spent fuel storage capability. Requests not meeting the physical need standard will also be considered for approval if they involve reprocessing contracts predating United States policy announced in 1977, if the requesting country is actively cooperating in exploring more proliferation-resistant methods of spent-fuel disposition, and if approval would further major non-proliferation objectives.
In 1978, two important subsequent arrangements dealt with the transfer of spent nuclear power reactor fuel from Japan to the United Kingdom and France for reprocessing. By the end of the fiscal year, the requests of two Japanese utilities, Tepco and Kansai, were ready for approval based on the requirements of the NNPA and the elements of current United States policy discussed above.
Views and Recommendations
The Department believes that United States non-proliferation interests and the energy needs of cooperating states can be satisfactorily served under the existing laws, regulations and review procedures. However, it will continue to keep these matters under review and, when appropriate, recommend revisions.
Classification
Introduction
DOE is responsible for establishing and implementing policy for the classification of restricted data, formerly restricted data, and national security information within DOE’s jurisdiction. This is done in accordance with the requirements of the Atomic Energy Act of 1954, as amended, and applicable Executive Orders. In addition, DOE is responsible for the continuous review of restricted data and other
6
classified information to determine what information may be declassified and disseminated without risk to national security.
Classification guidance has been developed and maintained over the years for all of DOE’s sensitive nuclear and nuclear-related programs such as weapons, uranium enrichment, inertial confinement fusion, and safeguards. This classification guidance is updated and revised to take into consideration such factors as nonproliferation objectives, technological progress, and foreign developments.
Specific classification initiatives were undertaken during 1978 as a result of DOE’s direct involvement in the United. States support of the INFCE and the national support efforts of the Non-Proliferation Alternative Systems Assessment Program (NASAPO. To protect sensitive information relating to the INFCE and NASAP studies, DOE (in conjunction with other concerned government agencies) developed a classification guide on nuclear proliferation. This document provides overall guidance for programs and studies related to the proliferation of special nuclear material and nuclear weapons. To encourage similar protection abroad, the United States has provided the guide to other countries.
In the belief that international cooperation will enhance the effectiveness of classification, in 1978 DOE initiated bilateral discussions and exchanges in this area. Unclassified guidance has been exchanged and further talks with additional countries are anticipated.
Views and Recommendations
It is important to obtain early agreement on classification among appropriate nations that may be potential suppliers of components and systems. National and international classification provides only transitory protection; the uniform application of classification by all industrialized nations would be desirable. When possible and appropriate, unclassified guidance should be exchanged with other nations to encourage uniform application of classification policy.
Cooperation in Strengthening International Safeguards and Physical Security
Introduction
The United States has provided technical assistance to the IAEA safeguards program since it began in 1961. To assist the agency in maintaining the necessary safeguards capability and effectiveness, the United States in 1976 established an expanded program of assistance funded at several million dollars per year (supported principally by the Agency for International Development). DOE, ACDA and NRC provide technical and managerial guidance as well as some funds. The DOE Office of Safeguards and Security has established an International Safeguards Program Office (ISPO) at the Brookhaven National Laboratory whose exclusive concern is the technical aspects of this work. ISPO/IAEA meetings have identified, and work has started, in six functional areas —nuclear material measurement technology, personnel training, system studies, information processing, surveillance and containment, and field operations support.
The U.S./IAEA cooperative program includes measurement technology, and training for IAEA staff and member state personnel, systems studies of IAEA safeguards, surveillance equipment for IAEA use in detecting diversion of nuclear materials, and safeguards exercises at United States nuclear facilities by IAEA personnel.
DOE physical security review visits abroad assure that physical security for nuclear materials and facilities is at least comparable to that recommended by the IAEA, a prerequisite to the issuance of export licenses by the U.S. for significant quantities of nuclear materials.
As an adjunct to these reviews, since 1974 DOE and its predecessor agencies have conducted a program of training and related cooperative
7
work in which foreign officials visit the United States to observe security systems at nuclear facilities. Five technical handbooks have been prepared by DOE covering all aspects of physical protection; these have been distributed to the IAEA and to foreign governments.
Views and Recommendations
It is recommended that DOE continue to participate in United States financial, technical and political support to the IAEA in order to strengthen its safeguards system. This support should be provided at a level and pace consistent with the IAEA’s ability to absorb and effectively to use United States assistance. The Department should also continue its R&D efforts to improve physical security measures and to promote international cooperation in this important area.
The U.S.-IAEA “Voluntary Offer’’ Safeguards Agreements
Introduction
Non-nuclear weapons states are obligated under the NPT to accept international safeguards on all their peaceful nuclear activities. Even though nuclear weapon states are not required to accept such safeguards, the United States announced in 1967 that when they are applied under the treaty, this nation will permit the International Atomic Energy Agency to apply its safeguards to all nuclear activities in the United States, except only those with direct national security significance. This voluntary offer, first announced by President Johnson and reaffirmed by Presidents Nixon, Ford, and Carter, was designed to encourage the widest possible adherence to the NPT and to allay concerns expressed by key non-nuclear weapon states that the safeguards would place them at a commercial disadvantage. The United States offer was an important consideration in West German and Japanese decisions to ratify the NPT.
A proposed U.S.-IAEA agreement to implement the offer, negotiated by staff of DOE’s
predecessor agencies in collaboration with representatives of the State Department and ACDA, was approved by the IAEA Board of Governors in September 1976. The President submitted the proposed agreement to the Senate on February 9, 1978, for ratification as a treaty. The Senate Foreign Relations Committee held hearings on the proposed U.S.-IAEA agreement on June 22, 1979.
The proposed agreement stipulates that the United States will provide the IAEA with a list of facilities eligible for safeguards. The IAEA will then designate the facilities in which it wishes to apply safeguards.
To permit prompt implementation of the agreement once it has been approved by the Senate, a DOE-DOS-ACDA-NRC working group has been developed a provisional list of eligible facilities. During 1978, the interagency group negotiated with the IAEA a number of general subsidiary arrangements for the implementation of safeguards and began work on specific “Facility Attachments” setting forth design information and safeguards procedures, including inspections for individual facilities considered most likely to be designated for safeguards application. DOE is taking other necessary steps to prepare its facilities to comply with IAEA safeguards requirements, and NRC has drafted appropriate regulation amendments to permit compliance by licensed facilities.
Views and Recommendations
It is recommended that concerned Senate committees give the proposed agreement their early attention, and that the Senate give its advice and consent to ratify as soon as possible.
United States Spent Fuel Storage Policy
Introduction
In October 1977, the United States announced that, in conjunction with a program for the storage of domestic spent power reactor fuel, it was prepared to accept limited quantities of foreign spent fuel for storage in this country when such action would serve our nonproliferation interests. At the same time, the
8
United States is encouraging other nations to develop their own storage plans and to support studies of regional or international spent fuel storage sites.
DOE will not commit funds or enter into subsequent arrangements for return of spent fuel to the United States prior to complying with the applicable requirements of the NNPA and the Department of Energy Act of 1978—Civilian Applications (Public Law 95-238). As a result of detailed studies and analyses made during 1978, DOE submitted legislation early in 1979 requesting the authority to receive foreign and domestic spent fuel, to take title to such fuel and to acquire storage facilities to implement a program.
Meanwhile, DOE has undertaken some essential first steps. Current efforts are centered on meeting NEPA requirements, developing a project licensing process, and examining fuel storage options. In 1978, DOE issued draft generic environmental impact statements on the storage of both domestic and foreign fuel, and the establishment of a fee for storage and disposal. When the final statements are issued, DOE will propose an initial fee and will issue an accompanying environmental assessment. Following legislative enactment, the Federal Government would enter into formal contracts with utilities for storage and disposal.
DOE has taken several steps to promote international cooperation in spent fuel storage. Technical support has gone to the IAEA, the NEA, and INFCE, and the United States has assisted India in determining the feasibility of densifying the storage pool at the Tarapur Power Reactor. Densification would permit Tarapur to operate for an additional 5 to 7 years without the necessity of having to remove accumulated spent fuel.
Views and Recommendations
To provide a credible alternative to reprocessing and to encourage national, multinational and international efforts to provide spent fuel storage capacity, the United States should implement the President’s offer of October 1977 to store limited quantities of foreign spent fuel when such action furthers U.S. non-proliferation interests.
The Department of Energy’s actions in providing support for international and multinational spent fuel storage facilities are substantially affected by the requirements of section 107 of Public Law 95-238, the DOE Act of 1978—Civilian Applications. That section establishes certain limitations on activities involving United States assistance to foreign spent fuel projects.
DOE is evaluating the impact of section 107. If experience shows that its requirements interfere with America’s ability to achieve foreign policy goals, re-examination and possible revision of that section may be in order.
Development of Proliferation-Resistant Fuel Cycle
Technologies
Introduction
As part of its non-proliferation responsibilities, DOE has been examining a variety of fuel cycles and nuclear systems under the NASAP and other programs to determine if proliferation risks of existing technologies can be reduced. The program seeks to:
1.	Identify nuclear systems and institutional arrangements with high proliferation resistance and commercial potential, and to assess their international acceptability.
2.	Develop strategies to implement the most promising alternatives.
3.	Provide technical support to United States participation in the INFCE program.
Technical data on a broad range of reactors and fuel cycles, including advanced reactor systems and advanced enrichment and reprocessing technologies, are being assessed in terms of such factors as proliferation resistance, potential for international deployment, uranium and fissile resource demand, and supply and commercial feasibility. NASAP is also focusing on uranium-efficient reactor and fuel systems that could be deployed by the year 2000 and that
9
would embody favorable combinations of proliferation-resistant features.
The following preliminary observations are offered, subject to later revision based on the final results of NASAP and INFCE:
1.	There is no demonstrated technical “fix” providing complete protection against proliferation; each technical option must be considered in the context of institutional arrangements.
2.	Recycle and breeder reactor systems are much less proliferation-resistant than once-through reactor systems.
3.	If improvements in fuel utilization and reduction in enrichment plant tails assay are introduced, the light water reactor (LWR) on the once-through cycle appears capable of providing an adequate nuclear energy supply well into the next century. At some time in the future the ability to expand uranium production may limit nuclear power growth on the once-through cycle if demand remains high.
4.	The next generation of nuclear fuel cycles (for example, breeders) will require more comprehensive and complex institutional and technical arrangements to improve proliferation resistance than present once-through cycles.
5.	Low enriched fuels being developed to replace high enriched fuels for research and test reactors (with little or no penalty to research capability) should improve proliferation resistance without significant impact on reactor performance.
Views and Recommendations
Pending the final results of NASAP and INFCE, the following tentative recommendations are offered for improving the proliferation resistance of the nuclear fuel cycle:
1.	Continued aggressive development and demonstration of improved lower-enrichment fuel for research and test reactors, to reduce the traffic in highly-enriched uranium and comply with the intent of the 1978 Non-Proliferation Act. Improved lower-enriched fuel would result in little loss in reactor performance or increase in cost, and would therefore be
expected to be acceptable to foreign and domestic reactor operators.
2.	Continuation of studies of increased fuel utilization in LWR’s, which have been very promising. Near-term approaches to such improvements as extending fuel burnup and reducing losses to control poisons could be demonstrated within the next decade.
3.	Continuation of conceptual design studies aimed at identifying means of reducing vulnerability of reprocessing facilities to the extent possible.
International Nuclear Fuel Cycle Evaluation
INFCE has joined together the United States, over fifty other nations and four international organizations in what is proving to be one of the most comprehensive international examinations of the nuclear fuel cycle yet undertaken. It is expected that the assembled data will be valuable to policy-makers of all countries for planning their nuclear power options and nonproliferation strategies.
Eight working groups are studying and preparing reports. These include:
1.	Estimates of the probable demand/supply balance for uranium.
2.	Estimates of the probable demand/supply balance for enrichment services and heavy water.
3.	Ways to improve nuclear fuel assurances to help meet energy needs, and possibly reduce national pressures for acquiring sensitive reprocessing and enrichment facilities.
4.	Assessments of the need, economics, and proliferation potential for chemical reprocessing, recycle in thermal reactors, and plutonium storage, including a review of alternatives to conventional reprocessing techniques.
5.	The probable role of the breeder, including a review of technical alternatives to the liquid metal fast breeder reactor that might have advantages from a nonproliferation standpoint.
10
6.	Ways to improve the capacity and availability of spent fuel storage.
7.	The characteristics of different waste management schemes.
8.	The attributes, including nonproliferation features, of a range of alternative nuclear power fuel cycles and reactor systems.
The final reports can provide a factual and analytical basis for decision-makers in developing future nuclear power programs that meet energy needs in ways that are more supportive of non-proliferation objectives.
11
Chapter 2
Proliferation Implications of Nuclear Systems
Scope and Approach
The purpose of this chapter is to assess the relative susceptibility of particular kinds of nuclear power technology to misuse, but not to compare the misuse of nuclear power to other ways of obtaining nuclear weapons. Such an assessment requires a baseline. The international community has already developed institutional arrangements which, depending upon the currently deployed once-through systems, can provide substantial protection against proliferation. The technical-institutional arrangements of the once-through fuel cycle serve as a useful point of departure for examining other systems.
The proliferation risk of nuclear power programs arises mainly from the access such programs may provide to materials, facilities and knowledge that could help to increase the capability of acquiring nuclear explosives. The proliferation possibilities considered here include both national and subnational misuse and involve weapons-related activities that may be overt or covert.
The approach taken by DOE in its Non-Proliferation Alternative System Assessment
Program (NASAP) is to treat three generic nuclear power systems and ancillary research activities as simplified, isolated entities. The three generic systems are: (1) the once-through fuel cycle, (2) recycle in thermal reactors, and (3) the fast breeder fuel cycle.
The world nuclear power picture is, of course, more complex than this three-system scheme might imply. The scope of national activities varies—from those countries that are just now contemplating the use of thermal reactors to those engaged broadly in nuclear power research. The latter case can include, for example, research reactors, enrichment plants, reprocessing capabilities and breeder activities coexisting with thermal reactors that now use fuel only once. The nature of different states’ efforts to reduce proliferation risks—the institutional context—also varies, for example, among Nuclear Non-Proliferation Treaty parties and nonparties.
The proliferation risks of the existing nuclear regime are complex and varied, comprising as they do both technical and institutional issues. Nevertheless, the insights developed in the comparisons among these simplified reference systems are proving useful in identifying the
13
risks of the current regime as well as possible measures to reduce those risks.
The proliferation resistance of nuclear power systems is assessed within NASAP in terms of the accessibility of weapons-usable material. When separated from other materials both uranium (with high concentrations in the isotopes U-235 or U-233) and reactor-produced plutonium are presumed to be nuclear weapons-usable materials, whether in oxide or metallic form. The activities examined include (1) the possible removal of materials from the fuel cycle, (2) the modification of an in-system facility or the construction of an out-of-system facility to be used for the conversion of the materials removed from the fuel cycle to weapons-usable form, and (3) the conversion itself. These required activities and the associated possibilities for detection and deterrence depend on the technical features of the fuel cycle under consideration and also on the safeguards, protective measures, and other institutional provisions that may apply.
Where appropriate, assessment factors are used as an aid to understanding the extent to which the difficulties of performing the indicated proliferation activities pose effective technical or political barriers to proliferation. The basic assessment factors—resources required, time required, and detectability—form a convenient grouping of larger numbers of factors that have been proposed elsewhere. The assessment procedure is summarized in table 1 and the assessment factors are defined in table 2.
The conclusions of this chapter are based on representative, rather than comprehensive, system descriptions; also, the NASAP analysis, particularly of breeder and thermal recycle systems, is preliminary. The following two sections briefly review the proliferation implications of several fuel enrichment and reprocessing technologies. The ensuing section, a shortened version of the paper on nonproliferation contributed by the United States to the International Nuclear Fuel Cycle Evaluation,1 examines the representative systems for the generic fuel cycles. While NASAP is examining the important question of the proliferation implications of research facilities, not all
Taper presented at Working Groups 5 and 8, INFCE
meeting, Vienna, September 1978.
types of research and development facilities are discussed in this report. A more detailed and classified version of this material is provided separately.2
It should be emphasized that the assessments contained in these annexes are of a preliminary nature. More complete results of DOE’s evaluations of the proliferation implications of alternative nuclear technology will be available upon the completion of the NASAP studies as well as those of INFCE.
Perspective on the Proliferation
Resistance of Enrichment Technologies
There are at least eight distinct technologies with a potential for economically enriching uranium to the 3 percent U-235 assay necessary to operate a light water reactor. All of the enrichment technologies entail proliferation risks to varying degrees, and while the contemplated plant designs are specialized to the production of reactor fuel, they might be adapted to the production of weapons-grade uranium. For each enrichment technology, this section addresses two primary proliferation concerns:
1. The development of a “dedicated” isotope separation plant for the production of high-enriched uranium (HEU).
2. The modification of existing commercial enrichment plants to produce HEU.
Techniques Used Presently
Gaseous Diffusion: In view of its cost and complexity, gaseous diffusion does not appear as a serious option for a country building a dedicated weapons facility.
One concern is how soon a diffusion plant could produce HEU after national seizure. Large gaseous diffusion plants such as those at Oak
Proliferation Implications of Nuclear Systems. Classified Appendix. Washington, 1979: U.S. Department of Energy DOE/PE-0014 (NNP-C)
14
Table 1.—Proliferation resistance assessment methodology
System characterization
Materials
Institutional contexts
Facilities and capabilities
Required proliferation activities
Facility preparation
Diversion
Material conversion
Assessment factors
Resources required
Time required
Detectability
	Table 2. —Definitions of assessment factors
Assessment Factors	Definitions
Resources required	The technological base, skills, manpower, and financial resources needed to carry out the activities required for the specified proliferation pathway; included is consideration of inherent difficulty of these activities.
Time required	The approximate time intervals needed to carry out the activities required for the specified proliferation pathway; included is preparation, diversion, and conversion.
Detectability	The risk of detection of activities in the proliferation pathway, including preparation, diversion, and conversion. •
Ridge, Portsmouth and Paducah consist of cascades of about 1,200 stages to enrich cumulatively uranium hexaflouride gas to approximately 3 percent U-235 (many more stages are necessary to go from natural uranium to a 90 percent U-235 assay). Material might be cumulatively enriched in several successive passes, or the operating conditions (and possibly the feed) could be modified. This second approach appears to be more feasible, and it might provide HEU of 50-70 percent enrichment within a few months of a takeover. Of concern is the covert addition of many more stages in order to produce HEU without batch recycle or modification of operating conditions. A safeguards program that permits at least periodic design verification should result in the detection of such a program. However, no ex
perience with safeguarding enrichment plants is available.
The Gas Centrifuge: The technical opportunities for HEU production in a commercial LEU plant arise because the plant is configured as hundreds of parallel cascades each of low throughput. The production of 100 kilograms of HEU a year would require only a 2 percent reduction of the LEU capacity of a 106 SWU/year plant; to produce it in a week would require the entire plant. Safeguards to detect the covert production of a few tens of kilograms of HEU per year would require the incorporation of safeguards considerations into the design of the plant. Other institutional arrangements, such as multinationalization, may also reduce the risks of diversion. If a nation were to overtly take over a commercial plant, HEU production
15
could, after a brief modification, proceed at a rate in excess of 10 kilograms a day in a typical 106 SWU/year plant.
There is no doubt that many countries have the design and construction skills to exploit the available data base and build at least a small number of experimental centrifuges. A dedicated facility of sufficient capacity to produce weapons-usable quantities of HEU per year would still require large numbers of machines.
Electromagnetic Separation: Calutrons—electromagnetic separators that employ the principle of the mass spectrometer—are of potential interest as a way of increasing the assay of partially enriched feed to a weapons level using a technology within the capability of many countries. Studies conducted for DOE suggest that the cost of a 100 kilograms/year system utilizing improved ion sources and magnets might be in the range of $22-100 million.
Since the calutron produces HEU and is unlikely to provide an economically feasible route to LEU, any indication that it is under commercial development must raise suspicion.
Advanced Techniques
Aerodynamic Methods: A sizable implementation of new aerodynamic enrichment will be a 200,000 SWU/year demonstration plant using the German “Becker Nozzle,’’ which the Federal Republic of Germany presently plans to export to Brazil in the 1980’s. The South African UCOR process, also an aerodynamic system, apparently uses a somewhat different technology (vortex tubes). Its proliferation implications are probably similar to those of the Becker process.
A fully developed commercial plant containing the optimal number of stages might generate 70 percent HEU during a period of approximately a month. However, a plant that has fewer than the optimal number of stages, such as the Brazilian demonstration plant, is not highly vulnerable to the type of “low reflux’’ operation that can provide a high-enriched product from LEU feed in a diffusion plant. But a batching approach could produce HEU in a manner that is governed by the modest equilibrium time of
the plant. Technologies available to the IAEA could probably be adapted to verify the correct operation of a 200,000 SWU/year aerodynamic separation plant (similar to that planned for Brazil).
It is estimated that the building of a dedicated 150 kilogram/year HEU plant would take several years, and cost in the range of $100-150 million.
Laser Isotope Separation: As part of DOE’s Advanced Isotope Separation (AIS) program, research on two fundamental laser isotope separation (LIS) processes is in progress at the Los Alamos Scientific Laboratory (LASL) and at the Lawrence Livermore Laboratory (LLL). Goals for both programs are the production of enriched uranium at less than 50 percent of the cost of the centrifuge. A program on laser separation is also being developed commercially by Jersey Nuclear Avco-Isotopes, Inc. The LLL atomic vapor system (AVLIS) uses visible wave length lasers to excite in U-235 a sequence of energy transitions in a stream of neutral uranium metal vapor, while the LASL molecular process (MLIS) uses an infrared laser to excite a molecular resonance in the U-235 component of UF6 gas.
The conceptual U.S. commercial plant designs for both processes involve the diverse disciplines of laser engineering, plasma physics, and advanced process materials management as well as the systems engineering needed to coordinate the elements. The proliferation concerns over advanced isotope separation processes are unique in that commercial or even pilot-scale plants do not presently exist. The earliest date that a plant might produce significant separative work in the United States would be the early 1990’s and a commercial plant may not be on-line until near 2000. Thus, in discussions of advanced, extremely complex separation techniques, the timing of their commercial application relative to the implementation of institutional and safeguards measures over the time period should be kept in mind.
After commercialization, the production of HEU would require major changes to certain elements of the LEU design. Production of HEU by commercial LEU plants of the United States designs would be possible in both AVLIS and MLIS, but only after process redesign and
16
modification of plant subsystems. With our current understanding of these designs, the effort could require several years and highly skilled laser and plasma physicists, process engineers and managers.
Covert removal of HEU clandestinely produced in a commercial plant is a safeguards concern. Since the United States processes and plant configurations are not yet frozen, opportunities exist for designing them to enhance the application of safeguards. If national takeover occurs, a several-month-long plant modification and checkout would likely be required before production of HEU is possible. The timely detection opportunities occurring in the R&D phase could have an effect in deterring a takeover, or in alerting the international community to a diversion.
For the near future, at least, a large R&D effort would be required to develop a small AVLIS or MLIS facility dedicated to HEU production; it could take 5 years and employ a staff of the order of hundreds. The demonstration of a commercial plant even with the process details being guarded, could accelerate the resolution of some physics questions, but the complex interdisciplinary systems problems would still have to be solved in building the plant.
The Plasma Separation System: As the third element of its AIS program, DOE conducts research on a non-laser plasma separation system. This process relies on well-known physics principles of the movement of charged particles in magnetic fields. Studies are underway to resolve how difficult modifiction of the design to production of HEU would be. As with the laser processes, at least for the near future a large R&D effort would be required to develop a small, dedicated plasma separation system.
Chemical Exchange: When certain pairs of uranium compounds are placed in contact with one another, chemical reactions occur at rates dependent to a slight degree on whether the compound is built on a U-235 or a U-238 atom. Thus, a cascade of contacting elements in which exchange reactions occur could provide, in principle, the basis of a separation system. This ap
proach has received major attention in France and some study in Japan during the past decade. In the U.S., a program is under way at the DOE Mound facility.
In the absence of a technological breakthrough, there could be a long time available for international response to a visible misappropriation of a commercial plant to HEU production. An LEU plant concept has been analyzed based on the Mound program and three pathways to HEU production have been quantified. Steady-state production of HEU could take years according to the shortest approach, in which LEU from the plant inventory is recycled.
The acquisition of data on the existing chemical exchange process could allow a country to engineer a slow-reacting dedicated HEU facility at a substantial cost (estimated as more than $120 million), if the country were to possess near state-of-the-art chemical engineering techniques. The chemical exchange process would not seem to be a promising candidate for HEU production.
In summary, it is concluded that for the major enrichment processes:
1.	At this time, the three advanced isotope separation processes under development within the AIS program and the chemical exchange technology appear to be resistent to both commercial misuse and to employment in dedicated facilities. But note that these processes are in initial stages of a long development program and are least well understood.
2.	Gaseous diffusion plants could produce HEU within a few months of a takeover.
3.	A commercial centrifuge plant could produce HEU within weeks of a takeover. Unclassified centrifuge technology can provide the basis for dedicated facilities. Clearly, the production of the thousands of elementary centrifuges needed for HEU production by a relatively undeveloped country might stress manufacturing capability. (This is an issue deserving further study.)
17
Proliferation Vulnerabilities of Reprocessing of Spent Fuel
Techniques Used Presently
The Purex process is the foundation for today’s commercial reprocessing technology. This process is derived almost wholly from nuclear weapons technology developed by the United States at the Savannah River and Hanford weapons production complexes. Hence, it is not difficult to understand the proliferation risk associated with this process.
The Purex process uses solvent extraction for separating uranium and plutonium from fission products and produces exceptionally pure streams of plutonium and uranium in the form of nitrates. Although the Purex process has been declassified, extensive experience with this complicated chemical technology is necessary for successful operation of a Purex-designed reprocessing plant.
Since countries with reprocessing plants would have easy access to weapons-usable plutonium (as well as ready-made production facilities if such use is desired), the ability to detect material diversion is of concern3. This concern is increased by the potentially long time that may be required for international verification of missing material.
Another problem arises from the fact that the widespread use of reprocessing could provide a cover for experimentation with Pu separation techniques without necessarily distinguishing between weapons activities and commercial nuclear power applications.
These concerns and problems have prompted an indefinite deferral of commercial reprocessing in the United States. During the period of deferral, the need for conventional reprocessing will be assessed. At the same time, an evaluation will be made of commercial reprocessing and of technical alternatives in conjunction with institutional arrangements that could potentially reduce the risks of proliferation. Several of
3This may be only a small portion of the plant’s throughput but still enough for several weapons.
these technical alternatives are discussed briefly below.
Alternative Techniques
Co-processing: To limit access to separated plutonium, such as occurs in the conventional Purex process, the uranium and plutonium can be co-processed or never fully separated. Since the uranium is mixed with the plutonium, the diversion of a given quantity of plutonium requires the removal of a much larger bulk of material (by a factor of 7 to 20) and, therefore, is easier to detect.
Co-decontamination and Spiking: If only a portion of the fission products is extracted from the uranium-plutonium-fission product mixture during chemical processing, then a gamma ray radiation source would remain with the plutonium and uranium. This partial separation is termed co-decontamination. The gamma ray radiation would provide a barrier to the unshielded removal and processing of the plutonium. However, partially decontaminated fuel will cool and the radiation barrier will diminish over time.
A variant of co-decontamination involves separating nearly all the fission products and then selectively separating one or more of the fission products to mix back into the co-processed uranium and plutonium after it is converted to oxide. The result would be a radiation barrier present in the mixed oxide while it is in storage and in the fabrication, transport, and storage of fresh fuel. Spiking of the co-processed uraniumplutonium oxide may be performed by adding either a neutron or gamma ray source, such as Co-60. Spiking of plutonium with a high neutron or heat emitter has also been considered, but it is not known if significant quantities of these spikants can be produced or whether the concept would be of sufficient utility for implementation.
There are significant uncertainties to be resolved, including evaluation of the procedures and facilities for handling radioactive fresh fuel at existing reactors and the behavior of fission products in the plutonium nitrate-to-oxide conversion process. Also, these techniques would increase fuel cycle costs and raise important safety and health questions.
18
Processes Other than Purex: There are several processes that can be used to perform one or more of the separations. On a laboratory scale, all of these can yield decontamination factors such that only one in 106 of the fission product activity remains in the product. Also, the separation factors for uranium and plutonium are relatively high; i.e., it is easy to perform the separation. As noted before, this level of separation was developed for the weapons program and thus would produce accessible plutonium that could be used in weapons. Nearly all processes can be utilized to produce clean, separated plutonium by staging, by material recycling or by modification of process control variables. Detailed design and process control, however, can inhibit process modification and enhance detectability.
An alternative to conventional Purex reprocessing has been suggested by the Electric Power Research Institute. Introduced in the spring of 1978, the Civex concept is based on the partial decontamination of the fuel to produce fast reactor fuels made with the Sol Gel process. (It is important to note that Civex is, at present, a concept and not a specific process.) Additional work is required to determine the specific features of reprocessing based on the Civex concepts and to define the effectiveness of the embedded proliferation-resistant features on which it is based.
Use denial is another concept being evaluated for reducing the proliferation vulnerability of reprocessing facilities. This concept, which is still in its infancy, consists of several techniques for disenabling the operation of a facility for an extended period of time and is intended to be used in conjunction with an elaborate command, control and communication system. The major problem with this concept is to devise techniques that would be acceptable to the facility operator.
The NASAP program is documenting the pertinent technical information that leads to judgments concerning the difficulty, cost, and time required for a proliferator to misuse the above technologies. This has been accomplished for several scenarios involving dedicated processing and reprocessing facilities. Those involving misuse of commercial facilities are incomplete at this time.
However, commercial reprocessing plants present major safeguards challenges. Serious questions have been raised as to whether the IAEA, given the present stage of safeguards development and its limited experience, will be able to provide timely detection of diversion of plutonium from reprocessing plants using Purex technology.
The IAEA has concluded that current material accountability is not adequate for effective safeguarding of the large reprocessing plants, and that increased reliance will have to be placed on containment and surveillance measures. Specific new measures will have to be developed for material accounting as well as improved containment and surveillance. These will be expensive to implement for both the IAEA and the operator, and even during the design and construction phases will require considerable scrutiny of facility operations. Most importantly, perhaps, is the need for dealing with the possible abrogation of safeguards commitments and national seizure of a reprocessing plant leading to a potential weapons production capability.
Proliferation-Resistance Assessments of Fuel Cycle Systems
The NASAP is examining a broad range of alternative fuel cycle systems. The current understanding of the proliferation resistance assessment of these systems is discussed here in three major classes: once-through, thermal recycle, and breeder. Examples of the possible advanced proliferation-resistant systems designs are also being assessed and will be reported when results become available.
Once-through Systems
Reference Once-through System: Light Water Reactor: A once-through LWR fuel cycle involves a number of steps. They include mining and milling of uranium ore, enriching uranium to a concentration of about 3 percent in the isotope uranium-235, fabricating the enriched
19
uranium into reactor fuel elements, using this fuel to operate the light water reactor, and then putting the spent fuel into long-term storage or permanent disposal. LWR fuel cycle activities, particularly enrichment, are today considerably less widely deployed than the reactors themselves.
The institutional context for the existing once-through system varies among countries. By ratifying the Non-Proliferation Treaty, more than 100 nations have agreed not to acquire or manufacture nuclear explosive devices and to subject all their peaceful nuclear activities, and any nuclear materials or facilities they export, to IAEA safeguards. As a result, safeguards now apply in many countries to materials and facilities of the de facto once-through LWR system.
As a consequence of various bilaterial supply agreements, non-NPT parties have also agreed not to acquire or manufacture nuclear explosives and to subject specific facilities and materials to IAEA safeguards. Both bilateral and multinational agreements may apply to the transfer of nuclear materials or technologies.
Proliferation Resistance of the Reference Once-through System: The most significant proliferation-resistant characteristic of the reference once-through nuclear power system is that there is never material that is directly weapons-usable in any part of the fuel cycle. Fresh fuel contains low concentrations of U-235 isotopically-diluted in a much larger amount of U-238; spent fuel contains low concentrations of U-235 and plutonium, (both of which are diluted in large amounts of U-238) and is accompanied by high radiation fields emitted by the products of fission. The only in-system facility capable of producing weapons-usable material would be a uranium enrichment plant. Modifying such a plant to produce weapons-usable material would entail varying degrees of difficulty, depending on the enrichment process used. The operating plants, which are expected to meet demand for decades, are located in relatively few countries.
The most significant proliferation activities are summarized below, their significance being considered in various national contexts.
Significant Proliferation Activities: Principal activities are noted in the following paragraphs.
In-System Enrichment Plant: The key proliferation activity associated with misuse of an existing enrichment plant designed to produce LEU would be modification of its operation or layout to permit production of HEU. While several enrichment methods exist, commercial enrichment is now performed in gaseous diffusion plants, with centrifuge plants just beginning commercial application. In gaseous diffusion plants, batch recycle could yield HEU over many months or even years, and would require cessation of LEU production. At a centrifuge plant, batch recycle or rearrangement of the cascades could yield HEU within a matter of weeks if all the separative capacity of the plant were used, or over a longer period with only a modest reduction in declared LEU production.
Out-of-System Enrichment: To build and test an enrichment facility, it could take a competent group of scientists and engineers, without specialized experience in enrichment, many years and hundreds of millions of dollars for a plant that would produce sufficient HEU for tens of weapons per year. (The commitment would be somewhat smaller for sufficient material for one or two weapons.) The elapsed time from first removal of material from the fuel cycle until weapons-usable material were available could be in the range of weeks and months to a year or more. The time would depend on the technology used, facility capacity, and start-up difficulties.
Out-of-System Reprocessing of Spent Fuel: Extracting plutonium from spent fuel would require building and testing a hot chemical separation facility. It could take a competent group of scientists and engineers, without specialized reprocessing experience, a few years and tens of millions of dollars to build a facility to separate sufficient plutonium for tens of weapons per year; as above, a somewhat smaller commitment would be required for one or two weapons. The elapsed time for first removal of spent fuel until weapons-usable material became available would be in the range of weeks to months.
Subnational Contexts: The subnational threat would be minimal in both the LWR-only case and in the case of an LWR with enrichment facility.
20
Improvements for Once-through Systems: Principal improvements are noted in the following paragraphs.
Safeguards and Institutional Arrangements: Upgraded safeguards on spent fuel in storage or in transit, combined with storage under interna-tional/multinational auspices, could significantly reduce the proliferation potential of this material by increasing the detectability of diversion. Upgraded safeguards on system enrichment facilities would make their misuse more detectable. Limiting the number of such facilities, emphasizing cooperative arrangements, including possible multinational or international arrangements, could retain the current level of proliferation resistance associated with the reference once-through system. Restraints on sensitive technologies coupled with reliable access to enrichment services could also make the preparation phase of a weapons program more difficult and timeconsuming and the identification of such an operation less ambiguous.
Improved LWR on the Once-through Cycle: Direct improvements in the LWR can result in more efficient burning of the uranium fuel and increased burning of the plutonium produced in situ. Improvements comparable to that of thermal recycle could be made in LWR’s by the turn of the century and many of the improvements may be retrofittable into existing plants.
These improvements have two strong nonproliferation advantages. First they would result in considerable reduction (—30 percent) in uranium consumption, relieving the pressure to pursue alternate, more sensitive technologies. And second, the improvements significantly reduce both the economic incentives for thermal recycle (already marginal) and the gain in fuel efficiency.
DOE is now pursuing a program to increase fuel utilization in LWR’s by approximately 15 percent by the late 1980’s and by 25 to 30 percent by the year 2000.
Other Once-through Systems: Another commercially deployed once-through system is the Canadian Deuterium Uranium (CANDU) Heavy Water Reactor (HWR). From the point of view of proliferation resistance, three features make it somewhat different from LWR’s:
1.	It uses natural uranium for the fuel, removing the need for enrichment services.
2.	It employs heavy water as moderator and coolant, a material that can be used in plutonium production reactors whose fuel is natural uranium.
3.	Refueling is on-line, rather than batch.
The export of heavy water production facilities is subject to multi-nationally agreed guidelines calling for application of safeguards, but the effectiveness of techniques for safeguarding such facilities has yet to be determined. The use of natural uranium results in more plutonium production in an HWR as compared to the reference LWR (approximately 500 kilograms versus 250 kilograms per gigawatt/year of operation), although the concentration per kilogram of fuel is lower. The use of on-line refueling makes the safeguarding of fuel assemblies somewhat more complex than with the reference LWR system. Improved systems have been devised although not yet deployed for safeguarding such reactors. Other once-through systems are also being considered, some of which are modifications of systems that are already widely deployed. For example, the use of slightly-enriched uranium in a heavy water reactor of the CANDU type would substantially increase its uranium efficiency. The enrichment services required would be much less than those of the reference LWR, and the amounts of plutonium discharged would be somewhat greater than the reference LWR (although reduced compared with the natural uranium-fueled HWR).
Alterations of light water reactor systems might range from changes in fuel management and burnup to changes in the material used for the fuel, including thorium. Improvements in uranium utilization are contemplated, some of which would result in a reduction of over 25 percent in the amount of plutonium produced annually. Changes involving thorium could be significant from the point of view of proliferation because increases in the enrichment level of uranium would be required. While the use of 20 percent enriched uranium would reduce by a factor of about five the separative work required to enrich fresh fuel for use in nuclear explosives, the amount of plutonium in the spent
21
fuel would be decreased, and the difficulty of extracting it would probably be increased. The use of highly enriched uranium feed would, of course, greatly decrease the proliferation resistance of the once-through cycle.
High temperature (gas-cooled) reactor (HTR) fuel cycle concepts are under consideration in NASAP, which would appear to permit low-enriched fresh fuel (less than 20 percent U-235), very high burnup, a comparatively low discharge of plutonium, and a comparatively low ratio of fissile plutonium discharged. In HTR fuel cycles that use low-enriched uranium and no thorium, fissile plutonium discharged annually would be about one-third that of a comparable-sized LWR. In HTR uraniumthorium cycles, fissile plutonium discharge would be still lower—on the order of one-tenth of that of a comparable-sized LWR. Uranium-233 would be produced, but the fuel cycle could be designed so that the uranium-233 would always be mixed with a sufficient quantity of uranium-238 to keep the uranium mixture below weapons-usable levels.
A fuller understanding of the proliferation implications of once-through systems other than the LWR will depend on further analyses taking place in NASAP.
Thermal Recycle Systems
Reference Thermal Recycle System—LWR: The technical base for fueling LWR’s with mixed oxides of uranium and plutonium (MOX) is well advanced, although no commercialized systems exist. The reference U-Pu thermal recycle system includes enrichment facilities, light water reactors, temporary spent fuel storage, reprocessing facilities, waste management facilities, and the transportation links between them.
Evaluation of proliferation resistance must not only treat a mature thermal recycle system but must also consider the pilot-scale or prototype facilities important for training of personnel and attaining reliable commercial-scale practice. Such facilities already exist or are under consideration in several countries, but not on a commercial scale. There is a significant variation in the institutional context for such programs. As these development programs evolve,
it is important to make sure that the institutional regime also evolves.
For the purpose of the reference case assessment, it is assumed that the thermal recycle is deployed with currently conceived, Purex-based reprocessing and MOX fuel refabrication within the context of the current institutional regime.
Proliferation Resistance of the Reference Thermal Recycle System: Compared to the once-through LWR system, the most apparent new proliferation characteristics of LWR recycle result from the potential of early, worldwide commerce in plutonium-bearing materials. Extensive thermal recycle could result in hundreds of thousands of kilograms of readily accessible Pu in international commerce by the year 2000. Separated plutonium woud be present in storage and in transport. Fresh fabricated MOX fuel itself could also be readily converted to weapons-usable form through chemical processes which require special although simple procedures.
The massive shielding needed for spent fuel reprocessing would not be necessary. Fuel elements have concentrations of plutonium of typically 3 to 5.5 percent, and much higher concentrations may be typical in feedstocks. Spent fuel has plutonium concentration less than 1 percent and is also accompanied by high radiation fields. Most important though is that thermal recycle could spread to most operators of thermal reactors, thus resulting in widespread plutonium commerce of hundreds of metric tons annually. Without further significant international institutional arrangements, one could expect in this case widespread proliferation of reprocessing facilities, MOX fabrication plants, and hot-labs for research and training in plutonium separation.
Significant Proliferation Activities: Principal proliferation activities are described briefly.
Conversion of Already Separated Plutonium: This process would be virtually identical to the reference LMFBR system.
Out-of-System Conversion of Fresh MOX Fuel Assemblies or Feedstocks: Also similar to the reference LMFBR except that more material would be available on a worldwide basis.
Out-of-System Reprocessing of Spent Fuel: This is also similar to the once-through LWR and the
22
LMFBR except that the plutonium concentration in the spent fuel is between that of the LWR and LMFBR.
National Context: Recycle LWR Only: For a country in which the national fuel cycle included only LWR’s using MOX fuels and their associated fresh fuel and interim spent fuel storage facilities, the significant nuclear power related proliferation pathways (in addition to those involving enrichment) would be: (1) to build an out-of-system facility to extract plutonium from fresh fuel assemblies, or (2) to build an out-of-system reprocessing facility to process spent LWR fuel.
Summary of Reference Thermal Recycle System: There would be three crucial proliferation vulnerabilities of the reference thermal recycle system, in addition to those of once-through systems. First, plutonium would be present in national facilities, in storage and in transit. This plutonium would be either in weapons-usable form or in forms that could be easily modified for such use. Second, relatively large flows of plutonium-bearing materials, often in bulk form, would be more difficult to safeguard effectively. Third, there could be a proliferation of national facilities for separation of and handling of plutonium, for R&D work on plutonium separation and for training and technology development. This technology is necessary although not sufficient for a weapons production capability.
A major strengthening of technical, safeguards and institutional controls would be required to mitigate these proliferation vulnerabilities significantly; some potential measures are discussed in a preliminary way in the following section.
Improvements for Thermal Recycle Systems: A broad array of technical and institutional measures could be applied to all fuel cycles. A preliminary discussion of how these might apply to the liquid metal fast breeder reactor (LMFBR) system is included on page 26. Although their application to an LWR recycle system would certainly differ in some important details, the analysis so far indicates that many of the basic considerations discussed there may apply. A significant difference, however, is that much less time may be available to bring the measures into action.
Some measures for radioactive contamination of fast reactor fuel would degrade the performance of thermal reactor fuel, although spiking with some materials (e.g., Co60) still appears feasible and worthy of further consideration. Furthermore, the dilution of plutonium concentration in MOX fuel for LWR recycle could be carried to a considerably greater extent than for breeder fuel; storage and shipment of feedstocks diluted to 10 percent concentration or less may be feasible and may be preferable from a proliferation point of view to high concentration feedstocks or metal. A more definitive analysis of these possibilities is needed and will result from other work in progress in NASAP.
Subnational Contexts: In case of LWR recycle with reprocessing and fabrication facilities, subnational groups would have potentially viable proliferational paths through the seizure of fresh fuel or the fresh fuel feedstocks in bulk form. Effective safeguards and physical security would be essential to prevent both diversion and seizure of materials. Because of the potential for near-term and widespread deployment of thermal recycle, the opportunities for subnational diversion would be greater than those presented by the LMFBR cycles.
Alternative Thermal Recycle Systems: This discussion of alternative systems is as preliminary as it is tenative. The following paragraphs present a few salient features, to be followed by the results of much more detailed work in NASAP.
Recycle systems other than the reference LWR are being considered in NASAP including improvements on light-water reactor systems, the introduction of recycle to heavy-water systems, and the development of high-temperature (gas-cooled) reactor systems. For LWR’s, the alternative concepts include thorium cycles in current-type LWRs, the use of a variable moderator (heavy water) to achieve spectral shift control, and the use of a variable geometry (such as in the light-water breeder reactor). Some HWR and HTR concepts would also utilize thorium.
Alternatives that would rely on thorium as the principal fertile material are being considered both to decrease consumption of natural fissile resources and to increase the potential
23
availability of “denatured” fuels.4 Using such fuels involves various combinations of thermal or fast reactors to produce the U-233 and other reactors to use the denatured U-233 fuels.
Spent denatured U-233 fuel would have lower plutonium content than ordinary LWR fuel (because of replacement of much of the U-238 in the fresh fuel with thorium) and, of course, it would maintain a substantial radiation barrier. Any uranium extracted from fresh denatured fuel would have to be further enriched to yield weapons-usable material. But separating U-233 from denatured fuel would require less separative work than separating U-235 of the same enrichment. Also, there is an inherent radiation barrier in fresh denatured U-233 fuel due to the accompanying U-232 and its daughters.
The value of denatured systems for proliferation resistance would depend heavily on effective multinational control over sensitive facilities.
Fast-Breeder Systems
Reference Fast-Breeder System: LMFBR: The Liquid-Metal Fast-Breeder Reactor (LMFBR) fueled with uranium and plutonium is the most technologically mature of the fast-breeder options, with demonstration facilities operational in a few countries. The reference U-Pu LMFBR system includes reactors, temporary spent fuel storage, reprocessing, fuel fabrication and refabrication facilities, waste management facilities and the transportation links between them. Enrichment would not be a part of the equilibrium LMFBR fuel cycle. However, the LMFBR would be started either from plutonium from LWR’s or from uranium enriched to 15 to 25 percent. For either startup case, an enrichment facility is implicitly needed.
Current fast-breeder programs are predicated on the use of stockpiled plutonium obtained by reprocessing thermal reactor spent fuel. The more restricted set of pathways associated with
4Denatured fuels are a mixture of uranium and thorium in which sufficient U-238 is present that the uranium itself, even if separated from the thorium, has sufficiently low fissile content to preclude its use in weapons without further enrichment. The fissile content of this low-enriched uranium may be either U-235 feed or U-233, produced by conversion of thorium.
a self-sustained system is emphasized in this section.
Existing breeder programs are underway in a small number of states and range from pilot and demonstration reactors to small research and fuel cycle facilities to support breeder research and development. The institutional context in which these programs operate also varies. Some, for example, are not subject to IAEA safeguards, and some assume a complete incountry fuel cycle while others do not. The institutional regime will likely evolve as these breeder development programs progress. This assessment assumes that the breeder fuel cycle is deployed within the context of the current institutional regime.
Proliferation Resistance of the Reference LMFBR Fuel Cycle: The most apparent proliferation implications of the reference LMFBR fuel cycle are the large commerce in plutonium-bearing materials that is required and the relatively high concentrations of plutonium in these materials. With the conventional Purex process, materials used as feedstock for the fresh fuel are directly usable in nuclear explosives; and, because of the lack of significant penetrating radiation, the fresh fuel itself can be easily converted to weapons-usable form. A much higher grade of weapons-usable material can be produced from blanket breeder spent fuel, requiring simple chemical processes with much less shielding precautions than for ordinary spent fuel. However, special handling would still be required.
Significant Proliferation Activities: These are described in the following paragraphs.
Conversion of Fresh Fuel or Fresh Fuel Feedstocks: Assuming facilities were not already available in the breeder fuel cycle, it would take a small but competent body of scientists and engineers several months and several million dollars to design, construct, and test facilities capable of extracting sufficient plutonium from fresh fuel assemblies to build tens of plutonium metal weapons per year. Less commitment of resources would be required if only one or two weapons were required (since these could be produced from the diversion of a single fresh fuel assembly) or if fresh fuel feedstocks were diverted.
24
The period from the time material was first removed from the fuel cycle until weapons-usable material were available would be dependent on the competence of the personnel involved. It could range from days to weeks, or possibly even hours if plutonium oxide from the fresh fuel was used directly.
Out-of-System Reprocessing of Spent Fuel: A competent body of experienced scientists and engineers in about a year could build and test a hot reprocessing facility capable of extracting plutonium from spent fuel. The cost would be tens of millions of dollars to build tens of (metalbased) weapons per year, with somewhat smaller commitments for one or a few weapons. Without specific experience, somewhat greater time and resources would be required. The time from removal of spent fuel from the fuel cycle until weapons-usable material became available could be in the range of weeks if experienced personnel were involved.
National Contexts: A number of examples are given.
LMFBR Only: For a country in which the national fuel cycle included only LMFBR’s with their associated fresh fuel and interim spent fuel storage facilities, the conversion of fresh fuel to weapons-usable form would be the technically easier path. If IAEA safeguards were in effect, the diversion of fresh or spent fuel would be subject to detection but the amount of fuel required is small. However, although item accounting could assure detection (because of the discrete nature of fuel assemblies), the timeliness of detection could be difficult to assure since conversion times are so short, particularly for fresh fuel. Without IAEA safeguards, the possibilities for detection of the removal of fuel would be even more limited.
LMFBR plus Reprocessing and Fabrication Facilities: For a country in which the national fuel cycle included the fuel fabrication, reprocessing, and refabrication facilities in addition to the LMFBR, all of the proliferation activities discussed earlier would be available.
For NPT parties, IAEA safeguards would apply throughout the LMFBR fuel cycle system. However, since the time from initial diversion to that of having weapons-usable material may be only days to weeks, the ability to assure timely detection could be difficult. Because of the large
flow of plutonium through the processing facilities, often in bulk form, the diversion of a relatively small sidestream over long periods of time could also be difficult to detect. Without IAEA safeguards the possibilities of detection would be extremely limited.
Subnational Contexts: In either case, i.e., the LMFBR alone or with reprocessing and fabrication facilities, subnational groups would have potentially viable proliferation paths through the seizure of fresh LMFBR fuel or the fresh fuel feedstocks in bulk form. Effective safeguards and physical security would be essential to prevent both diversion and seizure of materials.
Observations: From a proliferation resistance point of view, there are important differences between closed and once-through fuel cycles.
In comparison to the light water reactor on the once-thorough fuel cycle, the fast-breeder reactor fuel cycle poses increased proliferation risks for the following reasons:
1.	Fresh FBR fuel (MOX) is more vulnerable than low enriched uranium fuel.
2.	Deployment of FBR’s would legitimize reprocessing activities.
3.	The FBR fuel cycle could introduce substantial quantities of directly weapons-usable material in international commerce..
4.	The FBR fuel cycle could cause a spread of technology and trained manpower through involvement with international fuel service centers.
On the other hand, thermal recycle implies greater proliferation risks than fast-breeder reactor development for the following reasons:
1.	Thermal recycle could result in greater and more widespread international commerce in large quantities of weapons-usable material.
2.	Because of the worldwide spread of LWR’s, thermal recycle could pose an immediate and severe strain on existing safeguards and institutional capabilities.
3.	FBR’s are still in early development stages and even modest deployment outside countries in which they are being developed is not anticipated before the
25
turn of the century. Thus, the time scale of FBR deployment will permit more time to develop appropriate safeguards and institutional arrangements.
4.	Thermal recycle could contribute to premature deployment of sensitive reprocessing technology and facilities.
Closed fuel cycles, in general, would require great reliance on the effective operation of institutional measures and safeguards.
Improvements for LMFBR Systems: Some important features of these improvements are mentioned here in anticipation of much more extensive analyses being performed by the INFCE working groups.
Technical Measures: Isotopic dilution cannot render plutonium unusable for weapons in the way that diluting uranium-235 with uranium-238 does in once-through systems. However, radioactive contamination may be effected either by partial decontamination spiking or by pre-irradiation. Such process alterations would afford a protective radiation barrier to plutonium-bearing materials, particularly the fresh fuel. The radiation field could be substantial and (although not as high as that from just-discharged spent fuel whether LWR, HWR, or LMFBR) could require special handling and remote hot chemical processing to recover material usable in weapons.
Dilution with uranium may be effected either by mixing extracted plutonium with uranium at the output of a reprocessing plant or by coprocessing. Coprocessing schemes with partial decontamination could provide a measure of protection from the radiation standpoint that falls between uncontaminated materials and spent fuel (see below). However, if such reprocessing plants were deployed, it might still be possible to modify the process to produce material that would be directly usable in explosives. How widespread that capability might turn out to be would depend on the institutional context.
One technical approach would combine reprocessing and fuel fabrication and would have two possible objectives: (1) the reprocessing plant would be designed to create great difficulty for the operator in altering it to produce pure plutonium, and (2) the fresh fuel produced would be essentially as difficult to use as a spent fuel as a source of plutonium.
The practicality and effectiveness of designing such a facility to prevent misuse by the operators have not been resolved. It is not yet clear how much effective difference there is between such a process designed for civilian nuclear power activities and the Purex process. Even so, experience with such a plant would give the operators effective ground in at least some of the technology required to build independently a weapons-dedicated reprocessing facility. This problem, of course, could extend to multinational operation of reprocessing facilities (see discussion below of fuel centers).
In addition to such passive measures, one can conceive of active measures incorporated into fuel cycle facilities (including transport) that could—-if misuse were detected—automatically shut down certain operations and disrupt further operations, deny access to certain areas, or modify the form of target materials. Access denial, if practical, would have obvious advantages in protecting against seizure by subnational groups. Problems would arise in terms of acceptability to facility operators and national authorities.
Safeguards and Physical Security: Improvements in safeguards and physical security measures are also necessary for LMFBR systems. This is especially important for fresh breeder fuel because of the small number of assemblies needed; and, relative to spent fuel, the short time required to extract plutonium. Effective real-time monitoring of both fresh and spent fuel could be developed from technology that has proved to be be technically feasible. This could be aided by careful management to limit the quantity and duration of stockpiles of such materials.
To prevent subnational diversion, adequate physical security measures would be required. Some of the measures discussed in the previous section (for example, the introduction of a radiation barrier or coprocessing) and measures discussed in the next section (such as colocation) would serve to reduce the ease and opportunity of subnational seizure.
Detecting diversion from an LMFBR reprocessing plant would be extremely difficult because of the large throughput of plutonium-bearing materials. The development of more effective containment and surveillance and material accounting systems is important, although two goals will be difficult to meet: (1) developing and
26
implementing effective techniques for detecting long-term diversion of small amounts of material; and (2) meeting adequate timeliness goals for diversion of larger amounts.
Both of these difficulties pertain to national diversion, and the first may also be true for subnational diversion. The technical measures discussed above may make it easier to safeguard reprocessing plants. However, the benefits and drawbacks require careful study; one possible conflict is that the radiation from spiking or similar measures may make certain nondestructive assay instrumentation for accounting much less effective while improving the effectiveness of some surveillance and monitoring instrumentation.
Fuel Service Centers and Other Fuel Cycle Management Options: An important possibility for improving the proliferation resistance of LMFBR fuel cycles is to put sensitive materials and facilities under multinational control and to limit the number of such facilities. Bringing such facilities under multinational auspices would introduce the additional dimension of greater political constraint against abrogating safeguards. Moreover, the existence of such an entity would reduce the need and justification for independent national development of production facilities.
Three related measures deserve specific attention: (1) multinational (or international) spent fuel service centers, which contain facilities for fuel processing, fabrication, and other services; (2) careful management of fresh and spent breeder fuel to eliminate unnecessarily long periods when it is out of the reactor or not under multinational control; and (3) elimination of and/or hardening of transportation links to reduce the risk of sabotage, theft, or diversion.
Each of these measures may be supported by the technical improvements discussed above. For example, producing spiked or partially decontaminated fuel in a multinational fuel service center would lead to a system in which only reactors, short-term spent fuel storage facilities, and the fuel itself were dispersed outside the center, and in which the fresh fuel bore some similarity, in terms of the radiation barrier, to spent fuel.
Such multinational service centers could develop as a progression from cooperative ven
tures initiated on a more limited basis, in particular from arrangements to supplement national spent fuel storage, to provide enrichment services, or to store plutonium.
Observations: The assessment of the practicality and costs of the technical measures that are discussed as well as more speculative technical possibilities is incomplete. Moreover, their effectiveness as proliferation resistance measures needs careful analysis. The effectiveness of such institutional measures as multinational fuel cycle service centers, as well as their feasibility and acceptability to nations considering the use of breeders, is difficult to predict in advance of actual negotiation and implementation.
Alternative Fast-Breeder Systems: Two classes of alternatives are considered: (1) modifications of the ordinarily considered LMFBR and (2) other reactor types. This discussion of alternative systems is highly tentative and will be followed by the results of much more detailed work in NASAP.
The principal LMFBR alterations of interest are changes in the fuel type. Introducing thorium fuel to the system could not only affect performance, but would also permit a “denatured” fuel cycle where bred U-233 would be incorporated into fuel with U-238 and thorium for supply to thermal reactors. Because the U-233 would be mixed with U-238, enrichment would be required to obtain weapons-usable material. From the point of view of proliferation resistance, denatured fuel would have the greatest utility in a “symbiotic” system in which the deployment of sensitive facilities were restricted to multinationally-controlled centers, while the deployment of thermal reactors that use the denatured fuel were not. The question of the proliferation implications of such denatured fuel in itself is indicated briefly in the section on thermal recycle (page 22).
A distinct breeder type, the gas-cooled fastbreeder reactor (GCFBR), has been designed to operate on uranium-plutonium and/or thoriumuranium cycles. The form of the fuel would be very similar to that in which thorium is introduced for the LMFBR.
Another breeder reactor concept, the fast mixed spectrum reactor (FMSR) is under development at Brookhaven National Laboratory. Basically
27
a fast, once-through, breeder reactor, it offers a number of proliferation-resistant features that include no recovery or use of plutonium except on an in situ basis. The reactor concept offers an increase in uranium fuel utilization by approximately a factor of 15 over the conventional LWR without reprocessing and recycle. Disadvantages are very long fuel residence times and the need for reactor materials to withstand very high burnups—materials not yet available today. The FMRS concept, which would basically draw upon existing LMFBR or GCFR technology, is currently being studied by DOE.
This discussion has identified some of the alternative systems being considered in NASAP and other parts of DOE, and has tentatively indicated some of the features that may affect proliferation resistance. Further understanding of the effects of these features and identification of others will be an important function of the studies being conducted in NASAP.
Research Reactors
Numerous research and test reactors now in operation or planned were designed to utilize 90 to 93 percent enriched uranium to maximize flux performance per unit power and/or to minimize fuel cycle costs. Fabrication, transport, and storage of fuel for these reactors, particularly in the un-irradiated form, are of concern from a proliferation point of view. The larger fuel inventories associated with high-power test reactors increase the potential consequences of diversion. Elimination or substantial reduction of the trade in highly-enriched fuel elements for research and test reactors by substitution of reduced-enrichment fuel elements would lower the potential for using research and test reactor fuel as a source of material for nuclear explosives.
A program is underway in the United States to make feasible the fueling of most research and test reactors with uranium of less than 20 percent enrichment while maintaining the reactor performance. A small number of high-power, high-performance reactors needed for important work that cannot be reasonably accomplished in reactors with lower performance might have to continue to use high-enriched uranium. It is recognized, however, that for research and test
reactors of power greater than a few megawatts, fuel technology does not currently exist that would permit enrichment reductions to below 20 percent without severe reactor performance reductions (flux per unit power), expensive reactor modifications, and/or fuel cycle cost increases relative to highly enriched designs using 90 to 93 percent enriched uranium. The program now beginning in the United States is designed to develop the necessary fuel technology. Several years of work will be needed.
Currently proven fuel technology is capable of accommodating enrichment reductions to the 45 percent range (from 90 to 93 percent) without significant performance degradation or fuel cycle cost increase for many reactors in the 1 to 50 megawatt range (some reactors can be converted to less than 20 percent enrichment). Accordingly, as an immediate interim step, the United States is proposing to convert existing research and test reactors (and new designs) from the use of highly enriched fuel to the use of either 45 percent enriched fuel or 20 percent enriched fuel wherever this can be done without unacceptable reactor performance degradation. It appears this can be achieved without significant cost increase.
Proliferation Resistance
HEU Research Reactors: The removal of HEU from a research reactor to obtain sufficient material to build a nuclear explosive would require removal on a scale comparable to the annual fuel element requirement for a typical large research reactor. For instance, a 20 megawatt (thermal) research reactor may have about 200 grams of HEU in each fuel element. About sixty fuel elements are needed as replacements each year. For this example, more than an annual supply of fuel elements would have to be diverted to build a nuclear explosive. However, the fabrication of fuel elements for a given research reactor is normally performed on a special order basis and may involve considerable leadtimes. Thus, in the absence of measures to minimize HEU inventories, typical procurements of fresh fuel elements would otherwise be available and stored at the reactor site. Significantly large quantities of HEU are also present at the fuel fabrication facilities.
28
Moreover, large quantities of irradiated HEU can build up at research reactors, even ones of substantially lower power (e.g. 1 to 5 megawatts (thermal)).
LEU or Natural Uranium Reactors: Natural uranium-fueled research reactors produce plutonium at the approximate rate of 1 gram per megawatt (thermal) per day of operation. A typical natural uranium fueled 20 MWt research reactor would therefore produce about 5 kilograms of plutonium per year. The amount of plutonium produced is reduced as the enrichment level is increased. A 20 MWt research reactor using 10 to 20 percent enriched uranium would generate about 0.5 kilograms of plutonium per year.
The proliferation resistance of spent fuel from research reactors would be similar to that from nuclear powerplants with the following exceptions:
1. The amount of radioactivity from research reactor spent fuel can be as small as one fiftieth that of fuel from a commercial power reactor, so shielding problems may be less difficult to deal with.
2. There are several different chemical forms that are typically used for research reactor fuel elements, so that the steps involved in the chemical reprocessing would be altered.
Efforts to Improve the Proliferation Resistance of Research Reactors
The U.S. development program for enrichment reduction in research and test reactor designs currently using 90 to 93 percent enriched uranium is based on the practical criterion that
enrichment reduction should not cause significant flux performance (flux per unit power) or burnup performance degradation relative to the unmodified reactor design. To first order, this implies the requirement that the U-235 density in the reduced-enrichment case be the same as the U-235 density in the 90 to 93 percent enriched case. This can be accomplished by substitution of higher uranium density fuel technology for currently used fuel technology. Enrichment reduction potential is set in proportion to the available uranium density increase. It is recognized that, for research and test reactors of power greater than a few megawatts, fuel technology does not currently exist that would permit enrichment reductions to below 20 percent. As already indicated, a program is now beginning in the United States to develop the necessary fuel technology. The program is expected to last for several years.
Improved international safeguards and a more universal commitment to full scope safeguards would also be important for increasing the proliferation resistance of research reactors. Safeguards procedures need to accommodate the necessary flexibility of research reactor operations.
A long-term goal would be the achievement of a level of enrichment of between 3 and 20 percent. Enrichments in this range would maximize research reactor proliferation resistance. Increasing the enrichment of natural uranium research reactors to about 3 percent would substantially reduce their plutonium production and hence the availability of weapons-usable material in the spent fuel. Efforts to make existing technologies available on a commercial basis could make a significant contribution toward meeting this goal.
29
Table 3
LIST OF ACRONYMS
ACDA	Arms Control and Disarmament Agency
AIS	Advanced isotope separation program at DOE
AVLIS	Atomic vapor laser isotope separation process
CANDU	Canadian deuterium reactor, a power reactor of Canadian design fueled by natural uranium and moderated by heavy water (deuterium oxide)
DOE	Department of Energy
ERDA	Energy Research and Development Administration
EURATOM	European Atomic Energy Community, an arm of the European Community
EPTA	Enrichment plant tails assay—the percentage of the fissionable isotope U-235 remaining in the depleted material produced as a by-product of the enrichment process. A reduced tails assay means that more U-235 has been extracted from a given amount of natural uranium feed supplied to an enrichment plant.
FBR	Fast-breeder reactor, named for the speed of its neutrons
FMSR	Fast mixed-spectrum reactor
GCFBR	Gas-cooled fast-breeder reactor
GCFR	Gas-cooled fast reactor, a type of FBR
HEU	High-enriched uranium—uranium in which the percentage of isotope U-235 has been increased to more than 20 percent by enrichment
HTGR	High-temperature gas-cooled reactor
HTR	High temperature (gas-cooled) reactor
IAEA	International Atomic Energy Agency
31
INFCE
LASL
LEU
LIS
LLL
LMFBR
LWR
MLIS
MOX
NASAP
NEA
NNPA
NNWS
NPT
NRC
OECD
Pu
swu
Th
U-233
U-235
U-238
International Nuclear Fuel Cycle Evaluation
Los Alamos Scientific Laboratory
Low-enriched uranium, containing less than 20 percent of the fissionable isotope U-235; used as a fuel in light water reactors
Laser isotope separation process
Lawrence Livermore Laboratory
Liquid metal fast-breeder reactor, a type of FBR cooled by liquid sodium
Light water reactor, the type of power reactor in common use in the United States and abroad; moderated with ordinary water and fueled with LEU
Molecular laser isotope separation process
Mixed oxides of uranium and plutonium
Non-Proliferation Alternative Systems Assessment Program
Nuclear Energy Agency
Nuclear Non-Proliferation Act of 1978
Non-nuclear weapons states
Nuclear Non-Proliferation Treaty
Nuclear Regulatory Commission
Organization for Economic Cooperation and Development
Plutonium, which is created by the capture of a neutron by U-238. Pu-239 is a fissile isotope excellent for use in nuclear weapons. Pu-240 is a fissile isotope the presence of which complicates (but does not prevent) the construction of nuclear weapons because of its high rate of spontaneous fission. Pu can be used to fuel reactors in oxide form (Pu O2), usually as part of a mixed oxide fuel including uranium oxide (UO2).
Separative work unit—a measure of the difficulty in isotope separation, of producing from a supply of material of a given abundance a product of some other abundance
Thorium, a naturally radioactive element with atomic number 90 and, as found in nature, an atomic weight of approximately 232
Uranium-233, a fissionable isotope produced by irradiating thorium
Uranium-235, the naturally occurring fissionable isotope
Uranium-238, the most commonly occurring natural isotope or uranium normally non-fissionable, but fertile, or capable of being converted by irradiation under the proper circumstances into plutonium
32
United States Department of Energy Washington, DC 20585
Official Business
Penalty for Private Use, $300
FIRST CLASS MAIL
Postage and Fees Paid U.S. Department of Energy
DOE-350