[Federal Register Volume 66, Number 25 (Tuesday, February 6, 2001)]
[Proposed Rules]
[Pages 9055-9058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-3025]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 66, No. 25 / Tuesday, February 6, 2001 / 
Proposed Rules  

[[Page 9055]]



NUCLEAR REGULATORY COMMISSION

10 CFR Part 72

[Docket No. PRM-72-4]


Prairie Island Coalition; Denial of Petition for Rulemaking

AGENCY: Nuclear Regulatory Commission.

ACTION: Denial of petition for rulemaking.

-----------------------------------------------------------------------

SUMMARY: The Nuclear Regulatory Commission (NRC) is denying a petition 
for rulemaking (PRM) submitted by the Prairie Island Coalition (PRM-72-
4). The petitioner requested that the NRC undertake rulemaking to 
examine certain issues regarding the potential for thermal shock and 
corrosion of spent fuel in dry cask storage; amend its regulations 
governing the storage of spent nuclear fuel in dry storage casks to 
define the parameters of acceptable degradation of spent fuel in dry 
cask storage; amend its regulations to define the parameters of 
retrievability for spent nuclear fuel in dry cask storage; and require 
licensees to demonstrate safe cask unloading capability before a cask 
may be used at an independent spent fuel storage installation (ISFSI).

ADDRESSES: Copies of the petition for rulemaking, The Federal Register 
notice of receipt, the public comments received, and NRC's letter to 
the petitioner may be examined at the NRC Public Document Room, 11555 
Rockville Pike, Rockville, MD.
    You may also access these documents on NRC's interactive rulemaking 
website at http://ruleforum.llnl.gov. For information about the 
interactive rulemaking site, contact Ms. Carol Gallagher, 301-415-5905; 
e-mail ([email protected]).

FOR FURTHER INFORMATION CONTACT: Gordon Gundersen, Office of Nuclear 
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, 
Washington, DC 20555-0001, telephone 301-415-6195, e-mail 
([email protected]).

SUPPLEMENTARY INFORMATION:

The Petition

    On March 12, 1998 (63 FR 12040), the NRC published a notice of 
receipt of a petition for rulemaking filed by the Prairie Island 
Coalition (PIC). The petition consists of the issues presented in 
paragraphs 13, 14, and 15 of the document attached to an August 26, 
1997, letter from George Crocker, PIC, to L. Joseph Callan, Executive 
Director for Operations, NRC. The issues in the remainder of the August 
26, 1997, document were submitted as a petition under 10 CFR 2.206 of 
the Commission's regulations. The Director of the Office of Nuclear 
Reactor Regulation responded to this petition in a Director's Decision 
(DD-98-02) published on February 20, 1998 (63 FR 8703). Similar issues 
were addressed by the Director in a decision (DD-97-18) published on 
September 8, 1997 (62 FR 47227). Those issues concerned the 
degradation, retrievability, and unloading of spent nuclear fuel from 
dry storage casks.
    The petitioner requested an amendment of the regulations in 10 CFR 
part 72 to define the parameters of spent fuel degradation that are 
acceptable to the NRC under 10 CFR 72.122(h). Section 72.122(h) 
provides that spent fuel cladding must be protected during storage 
against degradation that leads to gross ruptures or that the fuel must 
be confined such that degradation will not pose an operational safety 
concern. The petitioner is concerned about the potential effect of 
spent fuel degradation on the ability of licensees to unload a dry 
storage cask safely. PIC contended that the NRC has not adequately 
addressed the possibility of damage to spent fuel caused by thermal 
shock when cool water refloods a cask that contains dry spent nuclear 
fuel. The petitioner also contended that the NRC has not adequately 
addressed degradation of spent nuclear fuel resulting from the loss of 
helium from failed cask seals or because of the passage of time. The 
petitioner stated that no procedures have been developed to ensure 
operational safety or to assess worker or offsite radiation exposure 
when degraded spent fuel must be unloaded.
    The petitioner also requested an amendment to the regulations in 10 
CFR part 72 that govern storage of spent nuclear fuel in dry storage 
casks to define the parameters of retrievability of spent fuel required 
by the NRC under 10 CFR 72.122(l). Section 72.122(l) states that spent 
fuel storage systems must be designed to allow ready retrievability of 
the spent fuel for future processing or disposal. PIC is concerned that 
the NRC has not taken into account the potential problems that may be 
encountered in unloading a cask to retrieve spent fuel.
    Lastly, the petitioner requested an amendment to the regulations to 
require licensees to demonstrate the ability to unload spent nuclear 
fuel safely from a dry storage cask before a cask can be used at an 
ISFSI. The petitioner contended that if a licensee can demonstrate 
ability to unload spent nuclear fuel safely from a cask in a pool after 
long-term storage, the public will have assurance that a spent fuel 
storage cask can be unloaded. PIC believes that although the NRC's 
regulations do not require a licensee to be able to unload a cask 
immediately, the NRC clearly requires a licensee to be able to unload 
the spent fuel at some point. The petitioner also believes that because 
in-pool unloading of spent fuel from a dry storage cask (that has 
contained the fuel for a protracted period) has not been completed, 
there is sufficient reason to require a licensee to demonstrate the 
capability to unload a dry cask underwater. PIC stated that it would be 
satisfied if a licensee can demonstrate the ability to unload spent 
nuclear fuel from a dry storage cask at some reasonable point in time.

Public Comments on the Petition

    The notice of receipt of the PRM invited interested persons to 
submit comments. The NRC received letters from 12 commenters: The State 
of Utah, five private organizations, three associated industries 
(including one from the Nuclear Energy Institute (NEI)), and three 
private individuals. The comments focused on the main elements of the 
petition-degradation, retrievability, and unloading of spent nuclear 
fuel from dry storage casks. The NRC also received responses from the 
petitioner and one of the commenters on many of the points raised in 
the comments. The NRC reviewed and considered comments and responses in 
developing its decision on this petition.
    Eight of the commenters supported this petition for rulemaking.

[[Page 9056]]

Commenters supporting the petition pointed out that a number of 
degradation modes exist for dry cask storage systems, including flawed 
cask fabrication, neutron flux and irradiation, liquid metal 
embrittlement, metal creep, hot metal reactivity, and thermal shock. 
These commenters believe that any of these modes of degradation may 
render unloading procedures ineffectual in terms of protecting workers, 
the public, and the environment from unacceptable radiation exposure. 
They believe that a rulemaking is needed to create procedures that 
ensure the safe management of the waste during a variety of contingency 
situations that may arise as a result of degradation.
    One commenter believes that a rulemaking is needed to provide a 
direct connection between NRC requirements and concerns about fuel 
integrity and the procedures necessary for monitoring, retrieving, 
repairing, and maintaining cask systems. The rulemaking would serve to 
reduce the uncertainties surrounding degradation, loading, and transfer 
of nuclear waste and should provide for the development of contingency 
analysis of the interaction between storage timelines, technologies, 
and degradation factors.
    Other commenters supported the rulemaking proposed by the 
petitioner to address a variety of issues, including the viability of 
retrieval of spent fuel from dry storage casks, the need to specify 
procedures for managing cladding degradation, the need to determine how 
damaged spent fuel will be managed after unloading (since damaged spent 
fuel cannot be placed in another cask), and whether special unloading 
procedures are needed for dual-purpose casks (which not only store fuel 
for an extended period but also transport the spent fuel to a 
repository or storage facility) because during transport the fuel may 
be subject to vibration and accidents.
    The State of Utah believes that a rulemaking is needed because the 
set of dry storage parameters is too vague and does not provide 
sufficient guidance for the NRC staff or cask designers. Further, the 
State believes that dry storage systems have operated with extremely 
thin safety margins, as evidenced by the welding problems experienced 
with the VSC-24 casks. In particular, the State notes that NRC's 
experience with the unloading of spent fuel from transportation casks 
does not provide a basis for confidence that storage casks can be 
successfully unloaded because of key differences between the two, 
primarily that the State believes that the cladding temperature in 
transportation casks is much cooler than the cladding temperature in 
storage casks and that transportation casks are used for a brief 
period, after which the fuel and cask interior can be inspected, which 
is not true for storage casks. The State also supports the petitioner's 
request that the NRC's regulations should require a physical 
demonstration of unloading ability and believes that a physical 
demonstration is particularly important at an off site ISFSI, given 
that the reactor and the spent fuel pool that supplied the irradiated 
fuel may no longer exist.
    The three industry commenters opposed the petition. The NEI 
observed that two Director's Decisions (DD-97-18 and DD-98-02) 
addressed the same issues with respect to the Prairie Island ISFSI and 
stated that the Director's responses demonstrate that there is no 
generic issue regarding safely unloading dry spent fuel storage casks, 
and hence no need for rulemaking. In NEI's view, experience, testing, 
and computer modeling have all shown that the combination of an inert 
atmosphere and temperature limits provides a robust basis to conclude 
that the integrity of the fuel will be maintained during the licensed 
storage period. NEI also believes that the fact that thousands of spent 
fuel assemblies have been successfully unloaded from shipping casks 
without damage--and that most of these shipping casks are designed for 
fuel temperatures higher than storage casks--provides confidence that 
storage cask unloading will not result in fuel damage. Moreover, NEI 
points out that the petition does not present any relevant technical, 
scientific, or other data to support the need for rulemaking.
    A cask manufacturer, Transnuclear, Inc., commented that 
Transnuclear metal casks are designed to store fuel below a maximum 
allowable fuel cladding temperature in an inert medium (helium) and 
that this is a well-established method of preventing cladding 
degradation. This commenter also stated that thermal shock to spent 
fuel assemblies is not a problem, that spent fuel assemblies have been 
successfully unloaded from shipping casks without damage, and that most 
of these shipping casks are designed for higher fuel temperatures than 
storage casks. Therefore, thermal shock will not present a significant 
problem when the casks are reflooded with spent fuel pool water before 
being unloaded. The commenter states that fuel temperature limits as 
high as 570 degrees Celsius have been approved for transportation 
packages and that unloading of fuel from a transportation cask into a 
spent fuel pool without causing fuel degradation has been demonstrated 
in the United States and France. In the case of unloading fuel from a 
storage cask, the commenter believed that the thermal shock phenomenon 
will be much less significant because of the lower fuel temperature 
(usually less than 300 degrees Celsius). In addition, the thermal shock 
is minimized by following procedures that allow the fuel to gradually 
cool down to the boiling point of water (100 degrees Celsius) before 
being submerged in the pool.
    The petitioner reviewed the comments received on its petition and 
provided a response. In the petitioner's view, rules governing 
procedures for safe management of contingency conditions during 
unloading do not presently exist and are needed. The petitioner states 
that the whole point of its request for rulemaking is that lack of 
actual knowledge about how waste materials will behave during storage 
and unavoidable management operations makes contingency planning 
necessary in order to protect against worker and public radiation 
exposure likely to occur if contingency procedures are not in place. 
The petitioner believes that phenomena such as high temperature zinc 
reactivity and thermal shock will allow site personnel very little time 
to evaluate the situation and initiate corrective action.

Reasons for Denial

    The NRC is denying the petition for the following reasons:
    The petitioners identified several concerns pertaining to the lack 
of specific guidance in the unloading procedure to address a scenario 
in which significant fuel degradation occurs during storage. The NRC 
staff agrees with the petitioners that such a scenario would complicate 
the unloading process by requiring additional measures and precautions 
to limit the release of radioactive materials from the cask into parts 
of the reactor facility and nearby environs. Currently, unloading 
procedures used by part 72 licensees include a hold point to sample the 
atmosphere within the cask cavity to test for radioactive and flammable 
gases before venting the cask cavity and removing the cask lid. On the 
basis of the analysis of the gas sample, the unloading procedure 
includes a step to allow personnel to determine whether additional 
measures or precautions are needed to safely unload the cask.
    While acknowledging many of the petitioner's concerns regarding the 
potential difficulties in retrieving degraded fuel from dry storage 
casks, the NRC staff concluded that licensees need not be required to 
incorporate specific guidance into the normal unloading procedure to 
address this

[[Page 9057]]

unlikely situation. This conclusion is based on the NRC staff's 
acceptance of current practices and that the required compensatory 
actions and precautions needed to address such contingency situations 
may vary significantly, depending on the actual results from the 
analysis of the gas sample. On the basis of licensees' experiences in 
developing and implementing plans to address the problem of fuel 
assemblies damaged during reactor operations, in handling radioactive 
wastes of various forms, and in resolving other comparable problems, 
the NRC staff has confidence that licensees could, if necessary, 
develop plans to retrieve damaged fuel from a storage cask while 
minimizing the radiological consequences to plant workers and the 
general public. In addition, the NRC staff is confident that the 
technical problems associated with retrieving degraded fuel could be 
overcome. Furthermore, requirements for planning and executing such an 
activity are contained in the licenses issued for each ISFSI and power 
reactor, and in NRC regulations at 10 CFR parts 20, 50, and 72. 
Therefore, the NRC staff has accepted gas sampling and defined hold or 
decision points before breaching the cask confinement boundary as an 
adequate means of addressing concerns pertaining to the unlikely 
degradation of fuel assemblies during storage. In addition, the NRC 
inspects loading and unloading procedures during preoperational testing 
to confirm their adequacy.
    The NRC believes that the petitioner is incorrect in asserting that 
10 CFR 72.122(h) needs to be revised to define parameters of acceptable 
spent fuel degradation. The NRC believes that an applicant may store 
spent fuel without significant degradation in a safe technical manner 
without additional prescriptive requirements. In the present case, 10 
CFR 72.122(h) specifies the performance-based outcome that must be 
achieved by the licensee. The applicant must address all relevant 
considerations to achieve the outcome specified in the regulation. 
Specifically, paragraph (h)(1) of 10 CFR 72.122 states, in part that: 
``[t]he spent fuel cladding must be protected during storage against 
degradation that leads to gross ruptures or the fuel must be otherwise 
confined such that degradation of the fuel during storage will not pose 
operational safety problems with respect to its removal from storage.''
    Research, experience, testing, and computer modeling have all shown 
that the combination of an inert atmosphere and establishment of 
cladding temperature limits provides an adequate technical basis for 
concluding that the fuel integrity will be maintained during the 
licensed storage period. Industry experience in unloading 
transportation casks under water without incurring fuel damage and 
limited experience in unloading storage casks provides confidence that 
storage cask unloading will also not result in fuel damage. Additional 
experience on the long-term performance of spent fuel storage systems 
has been gained from NRC-sponsored studies. Specifically, the NRC 
studied spent nuclear fuel assemblies that have been out of the reactor 
for approximately 20 years. In September 1999, a Castor-V/21 cask that 
has been at the Idaho National Engineering and Environmental Laboratory 
since 1985 was reopened, and the cask internals, fuel assemblies, and 
several rods were visually inspected. This cask contained 21 spent 
pressurized water reactor fuel assemblies (with burnup in the 30-35 
GWd/MTU range) from the Surry Nuclear Power Plant. These fuel 
assemblies have been in continuous storage in this cask for 
approximately 15 years. The examinations found no evidence of 
significant degradation of the Castor-V/21 cask systems important to 
safety from the initial cask loading in 1985 to the time of examination 
in 1999. The fuel examination found no long-term fuel degradation, thus 
confirming the adequacy of existing practices to protect the fuel.
    The NRC believes that the petitioner and the commenters have not 
provided adequate justification for revising the requirements in 10 CFR 
72.122(l) to include specific parameters for retrievability. The NRC 
reviews an applicant's method of retrievability to determine if it is 
appropriate for use rather than specifying in the regulations exactly 
how retrievability is to be accomplished. Each site must have specific 
procedures in place that are exclusively associated with that site, and 
the licensee should have the flexibility of achieving the outcome 
specified in 10 CFR 72.122(l).
    Furthermore, Regulatory Guide 3.61, ``Standard Format and Content 
of Topical Safety Analysis Reports for a Spent Fuel Dry Storage 
Facility'' contains an outline of the specific information needed, and 
NUREG-1536, ``Standard Review Plan for Dry Cask Storage Systems'' 
provides guidance to the NRC staff performing safety reviews of dry 
cask storage systems. These documents provide guidance to applicants 
and the NRC staff to ensure that the safety analysis report (SAR), the 
safety evaluation report, and the Certificate of Compliance contain 
commitments to prepare and validate procedures, and to train qualified 
personnel in their use so that spent fuel can be retrieved safely from 
a dry storage cask.
    The NRC staff agrees with the petitioner's premise that actually 
unloading a storage cask would likely result in licensees learning 
lessons that could improve unloading procedures. The staff does not 
agree that additional demonstration of the unloading procedure is 
warranted. In addition to the NRC staff's review of the procedure for 
unloading casks, reasonable assurance that the casks can be safely 
unloaded is provided by a variety of experiences related to the use and 
storage of radioactive materials. These experiences include 
preoperational tests and dry-run exercises that are performed to verify 
key aspects of unloading procedures for casks; related research 
sponsored by the commercial nuclear industry, the U.S. Department of 
Energy, and the NRC; actual loading and unloading of transportation 
casks; loading of storage casks; handling of spent fuel assemblies 
under various conditions; and performing relevant maintenance and 
engineering activities associated with reactor facilities. In addition, 
as discussed below, there is recent experience from unloading a spent 
fuel storage cask at Surry. Accordingly, the NRC believes that the 
request of the petitioner and some commenters to require a 
demonstration of cask unloading before a cask can be used at an ISFSI 
is unnecessary.
    The NRC staff also believes that adequate assurances are in place 
to ensure safe cask unloading. As part of the review described in 
NUREG-1536, the NRC staff verifies that the SAR has requirements for 
cask unloading procedures. The NRC inspects procedures, training and 
qualification, and ISFSI operations. Further, requiring a full 
demonstration of cask unloading could result in unnecessary radiation 
exposure to workers and the public.
    The NRC staff's view that adequate assurances are in place to 
ensure safe cask unloading are borne out by the practical experience in 
retrieving dry storage casks that have been stored with spent fuel for 
a number of years. In 2000, two TN-32 spent fuel storage casks at Surry 
were retrieved from the storage pad because of indications of a failed 
seal. In one case, the seal monitoring system had developed a leak. The 
cask was returned to the pool, the seals replaced, the monitoring 
system repaired, and the cask leak tested. The cask was then returned 
to the ISFSI pad. The second cask had a leak in the secondary seal. The 
primary seal was intact. The cask was returned to the pool and the lid 
removed to

[[Page 9058]]

replace the seals. Localized corrosion was discovered on the sealing 
surface of the lid. The fuel was unloaded while repairs were made to 
the sealing surface. After the sealing surfaces were restored and the 
seals replaced, the cask was reloaded, leak tested, and returned to the 
storage pad. During these operations, no releases of radiation to the 
environment occurred and no spent fuel degradation was found. These two 
casks were initially loaded and placed in storage in 1996. More 
information can be found in NRC Inspection Report 72-002/2000-06.
    The petitioner believes that the NRC has not evaluated phenomena 
such as high-temperature zinc reactivity and thermal shock that will 
allow site personnel very little time to evaluate the situation and 
initiate corrective actions. The NRC staff reviews areas such as 
thermal loading, inadvertent criticality, and structural or containment 
failure for normal and abnormal conditions that are addressed by the 
designer of the storage system. NRC places thermal load limit 
restrictions on casks approved for use and requires that fuel be stored 
in an inert atmosphere. Although no adverse effects of zinc on the 
cladding of the spent fuel stored in NRC certified casks have as yet 
been identified, NRC has initiated a research project to investigate 
the possible effects of zinc on spent fuel cladding.
    The NRC staff believes that the petitioner has identified a valid 
concern regarding the potential recovery of fuel assemblies that 
unexpectedly degrade during storage. However, in this unlikely event, 
the NRC staff has concluded that there is reasonable assurance that a 
licensee can safely unload degraded fuel or address other problems. 
This conclusion is based on the NRC's defense-in-depth approach to 
safety that includes requirements to design and operate spent fuel 
storage systems that minimize the possibility of degradation; 
requirements to establish competent organizations staffed with 
experienced, trained, and qualified personnel; and NRC inspections to 
confirm safety and compliance with requirements. The NRC staff finds 
acceptable these procedures for detecting degraded fuel through 
sampling and, on the basis of the sample results, the implementation of 
appropriate recovery provisions that reflect the ALARA (as low as is 
reasonably achievable) requirements. The NRC staff's acceptance of this 
approach is based on the fact that the spent fuel storage cask can be 
maintained in a safe condition during the time needed to develop the 
necessary procedures and to assemble the appropriate equipment before 
proceeding with cask unloading. The NRC staff also relies on the 
considerable radiological safety experience available in the nuclear 
industry in its assessment that appropriately detailed procedures can 
be prepared for the specific circumstances in a timely manner.
    For the reasons cited in this document, the NRC denies this 
petition.

    Dated at Rockville, Maryland, this 18th day of January, 2001.

    For the Nuclear Regulatory Commission.
William D. Travers,
Executive Director for Operations.
[FR Doc. 01-3025 Filed 2-5-01; 8:45 am]
BILLING CODE 7590-01-P