[Federal Register Volume 60, Number 186 (Tuesday, September 26, 1995)]
[Rules and Regulations]
[Pages 49495-49505]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-23803]



=======================================================================
-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

RIN 3150-AF00


Primary Reactor Containment Leakage Testing for Water-Cooled 
Power Reactors

AGENCY: Nuclear Regulatory Commission.

ACTION: Final rule.

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

SUMMARY: The Nuclear Regulatory Commission is amending its regulations 
to provide a performance-based option for leakage-rate testing of 
containments of light-water-cooled nuclear power plants. This option is 
available for voluntary adoption by licensees in lieu of compliance 
with the prescriptive requirements contained in the current regulation. 
This action improves the focus of the regulations by eliminating 
prescriptive requirements that are marginal to safety. The final rule 
allows test intervals to be based on system and component performance 
and provides licensees greater flexibility for cost-effective 
implementation methods of regulatory safety objectives.

EFFECTIVE DATE: October 26, 1995.

FOR FURTHER INFORMATION CONTACT: Dr. Moni Dey, Office of Nuclear 
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 
20555, telephone (301) 415-6443, e-mail [email protected]

SUPPLEMENTARY INFORMATION:

Background--Development of Proposed Rule

NRC's Marginal-to-Safety Program

    In 1984, the NRC staff initiated a program to make regulatory 
requirements more efficient by eliminating those with marginal impact 
on safety. The NRC's initiative to eliminate requirements marginal to 
safety recognizes both the dynamic nature of the regulatory process and 
that the importance and safety contribution of some existing regulatory 
requirements may not have been accurately predicted when adopted or may 
have diminished with time. The availability of new technical 
information and methods justify a review and modification of existing 
requirements.
    The NRC solicited comments from industry on specific regulatory 
requirements and associated regulatory positions that needed 
reevaluation. The Atomic Industrial Forum conducted a survey providing 
most of industry's input, published for the NRC as NUREG/CR-4330 
1, ``Review of Light Water Reactor Regulatory Requirements,'' Vol. 
1, April 1986. A list of 45 candidates for potential regulatory 
modification were identified. The NRC's review of the list selected 
Appendix J as one of seven areas requiring further analysis (NUREG/CR-
4330, Vols. 2 and 3, dated June 1986 and May 1987). The NRC also 
conducted a survey of its staff on the same issue. The NRC staff survey 
identified 54 candidates for regulatory modification, a number of which 
were previously identified in the industry survey. The NRC's assessment 
of this list also selected Appendix J as a potential candidate for 
modification.

    \1\ Copies of NUREGs may be purchased from the Superintendent of 
Documents, U.S. Government Printing Office, P. O. Box 37082, 
Washington, DC 20013-7082. Copies are also available from the 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161. A copy is available for inspection and/or 
copying in the NRC Public Document Room, 2120 L Street, NW. (Lower 
Level), Washington, DC.
---------------------------------------------------------------------------

    The NRC published in the Federal Register, for comment, a proposed 
revision to Appendix J on October 29, 1986 (51 FR 39538) to update 
acceptance criteria and test methods based on experience in applying 
the existing requirements and advances in containment leak testing 
methods, to resolve interpretive questions, and to reduce the number of 
exemption requests. This proposed rule was withdrawn from further 
consideration and superseded with a more comprehensive revision of 
Appendix J.
    The NRC published a notice in the Federal Register on February 4, 
1992 (57 FR 4166), presenting its conclusion that Appendix J was a 
candidate whose requirements may be relaxed or eliminated based on 
cost-benefit considerations. On the basis of NRC staff analyses of 
public comments on the proposal, the Commission approved and announced 
on November 24, 1992 (57 FR 55156) its plans to initiate rulemaking for 
developing a performance-oriented and risk-based regulation for 
containment leakage-testing requirements. On January 27, 1993, (58 FR 
6196) the NRC staff published a general framework for developing 
performance-oriented and risk-based regulations and, at a public 
workshop on April 27 and 28, 1993, invited discussions of specific 
proposals for modifying containment leakage-testing requirements. 
Industry and public comments on the proposals, and other 
recommendations and innovative ideas raised at the public workshop, 
were documented in the proceedings of the workshop (NUREG/CP-0129, 
September 1993). Specifically, the NRC concluded that the allowable 
containment leakage rate utilized in containment testing may be 
increased and other Appendix J requirements need not be as prescriptive 
as the current requirements. To increase flexibility, the detailed and 
prescriptive technical requirements contained in Appendix J regulations 
could be improved and replaced with performance-based requirements and 
supporting regulatory guides. The regulatory guides would allow 
alternative approaches, although compliance with existing regulatory 
requirements would continue to be acceptable. The performance-based 
requirements would reward superior operating practices.
    The present rulemaking is part of this overall effort and 
initiative for eliminating requirements that are marginal to safety and 
is guided by the policies, framework and criteria for the 

[[Page 49496]]
program. A more comprehensive proposed rule than that proposed in 1986 
that accounts for the latest technical information and regulatory 
framework, using performance-oriented and risk-based approaches, was 
published by the NRC in the Federal Register on February 21, 1995. The 
public comment period for the proposed rule closed May 8, 1995.

NRC's Regulatory Improvement Program

    The NRC's marginal-to-safety initiative is part of a broader NRC 
initiative for regulatory improvement. Through its Program for 
Regulatory Improvement, the NRC has institutionalized an ongoing effort 
to eliminate requirements marginal to safety and to reduce the 
regulatory burden on its licensees. The NRC staff's plan, summarized in 
SECY-94-090, dated March 31, 1994, satisfies the requirement for a 
periodic review of existing regulations given in Executive Order 12866 
of September 30, 1993. This plan was approved by the Commission on May 
18, 1994. The Regulatory Improvement Program is aimed at the 
fundamental principle adopted by the Commission that all regulatory 
burdens must be justified and that its regulatory process must be 
efficient. In practice, this means the elimination or modification of 
requirements for which burdens are not commensurate with their safety 
significance. The activities of the Regulatory Improvement Program 
should result in enhanced regulatory focus in areas that are more 
safety significant. As a result, an overall net increase in safety is 
expected from the program.
    The Regulatory Improvement Program will include, whenever feasible 
and appropriate, the consideration of performance-oriented and risk-
based approaches. The program will review requirements or license 
conditions that are identified as a significant burden on licensees. If 
review and analysis find that the requirements are marginal to safety, 
they will be eliminated or relaxed. By performance-oriented, the NRC 
means establishing regulatory objectives without prescribing the 
methods or hardware necessary to accomplish the objective, and allowing 
licensees the flexibility to propose cost-effective methods for 
implementation. By risk-based, the NRC means regulatory approaches that 
use probabilistic risk analysis (PRA) as the systematic framework for 
developing or modifying requirements.
    In institutionalizing the Regulatory Improvement Program and 
adopting a performance-based regulatory approach, the NRC has 
formulated the following framework for revisions to its regulations:
    (1) The new performance-based regulation will be less prescriptive 
and will allow licensees the flexibility to adopt cost-effective 
methods for implementing the safety objectives of the original rule.
    (2) The regulatory safety objectives will be derived, to the extent 
feasible and practical, from risk considerations with appropriate 
consideration of uncertainties, and will be consistent with the NRC's 
Safety Goals.
    (3) Detailed technical methods for measuring or judging the 
acceptability of a licensee's performance relative to the regulatory 
safety objectives will be, to the extent practical, provided in 
industry standards and guidance documents which are endorsed in NRC 
regulatory guides.
    (4) The new regulation will be optional for current licensees so 
that licensees can decide to remain in compliance with current 
regulations.
    (5) The regulation will be supported by necessary modifications to, 
or development of, the full body of regulatory practice including, for 
example, standard review plans, inspection procedures, guides, and 
other regulatory documents.
    (6) The new regulation will be formulated to provide incentives for 
innovations leading to improvements in safety through better design, 
construction, operating, or maintenance practices.

Current Appendix J Requirements

    Appendix J to 10 CFR Part 50, ``Primary Reactor Containment Leakage 
Testing for Water-Cooled Power Reactors,'' became effective on March 
16, 1973. The regulatory safety objective of reactor containment design 
is stated in 10 CFR Part 50, Appendix A, ``General Design Criteria for 
Nuclear Power Plants,'' Criterion No. 16, ``Containment Design.'' GDC 
Criterion 16 mandates ``an essentially leak-tight barrier against the 
uncontrolled release of radioactivity to the environment * * *'' for 
postulated accidents. Appendix J to 10 CFR Part 50 implements, in part, 
General Design Criterion No. 16 and specifies containment leakage-
testing requirements, including the types of tests required. For each 
type of test required, Appendix J specifies how the tests should be 
conducted, the frequency of testing, and reporting requirements. 
Appendix J requires the following types of containment leak tests:
    (1) Measurement of the containment integrated leakage rate (Type A 
tests, often referred to as ILRTs).
    (2) Measurement of the leakage rate across each pressure-containing 
or leakage-limiting boundary for various primary reactor containment 
penetrations (Type B tests).
    (3) Measurement of the containment isolation valves leakage rates 
(Type C tests).
    Type B and C tests are referred to as local leakage-rate tests 
(LLRTs).

Leak-Tightness Requirements

    Compliance with 10 CFR Part 50, Appendix J, requirements is 
determined by comparing the measured containment leakage rate with the 
maximum allowable leakage rate. Maximum allowable leakage rates are 
calculated in accordance with 10 CFR Part 100, ``Reactor Site 
Criteria,'' and are incorporated into the technical specifications. 
Typical allowable leakage rates are 0.1 percent of containment volume 
per day for pressurized water reactors (PWRs) and one volume percent 
per day for boiling water reactors (BWRs).

Test Frequency Requirements

    Schedules for conducting containment leakage-rate tests are 
specified in Appendix J for both preoperational and periodic tests. 
Periodic leakage-rate test schedules are as follows:
Type A Tests
    (1) After the preoperational leakage-rate test, a set of three Type 
A tests must be performed at approximately equal intervals during each 
10-year service period. The third test of each set must be conducted 
when the plant is shut down for the 10-year plant in-service 
inspection.
    (2) The performance of Type A tests must be limited to periods when 
the plant facility is nonoperational and secured in the shutdown 
condition under administrative control and in accordance with the 
safety procedures defined in the license.
    (3) If any periodic Type A test fails to meet the applicable 
acceptance criteria, the test schedule applicable to subsequent Type A 
tests will be reviewed and approved by the Commission. If two 
consecutive periodic Type A tests fail to meet the applicable 
acceptance criteria, a Type A test must be performed at each plant 
shutdown for refueling or approximately every 18 months, whichever 
occurs first, until two consecutive Type A tests meet the 

[[Page 49497]]
acceptance criteria, after which time the regular retest schedule may 
be resumed.
Type B Tests
    (1) Except for airlocks, Type B tests must be performed during 
reactor shutdown for refueling, or other convenient intervals, but in 
no case at intervals greater than 2 years. If opened following a Type A 
or B test, containment penetrations subject to Type B testing must be 
tested prior to returning the reactor to an operating mode requiring 
containment integrity. For primary reactor containment penetrations 
employing a continuous leakage monitoring system, Type B tests, except 
for tests of airlocks, may be performed at every other reactor shutdown 
for refueling but in no case at intervals greater than 3 years.
    (2) Airlocks must be tested prior to initial fuel loading and at 
six-month intervals thereafter. Airlocks opened during periods when 
containment integrity is not required by the plant's technical 
specifications must be tested at the end of such periods. Airlocks 
opened during periods when containment integrity is required by the 
plant's technical specifications must be tested within 3 days after 
being opened. For airlock doors opened more frequently than once every 
3 days, the airlock must be tested at least once every 3 days during 
the period of frequent openings. For airlock doors having testable 
seals, testing the seals fulfills the 3-day test requirement. Airlock 
door-seal testing must not be substituted for the 6-month test of the 
entire airlock at not less than Pa, the calculated peak 
containment pressure related to the design basis accident.
Type C Tests
    Type C tests must be performed during each reactor shutdown for 
refueling, but in no case at intervals greater than 2 years.
    There have been two amendments to this Appendix since 1973. The 
first amendment, published September 22, 1980 (45 FR 62789), modified 
the Type B penetration test requirements to conform to what had become 
accepted practice through the granting of exemptions. The second 
amendment, published November 15, 1988 (53 FR 45890), incorporated the 
Mass Point Statistical Analysis Technique as a permissible alternative 
to the Total Time and Point-to-Point techniques specified in Appendix 
J.

International Experience

    A combination of Type A tests and an on-line monitoring (OLM) 
capability is being actively pursued in Canada and Europe, notably in 
France and Belgium, and is currently being considered in Sweden. OLM is 
used to identify a ``normal'' containment pressurization pattern and to 
detect deviations from that pattern. With on-line, low-pressure 
testing, Hydro-Quebec's Gentilly-2 station is able to monitor the 
change in containment leaktightness between Type A tests. The Belgians 
conduct a leakage test using OLM during reactor operation after each 
cold shutdown longer than 15 days with the objective of detecting gross 
leaks. The objective of the Belgian approach to Type A testing is to 
reduce the frequency and duration of the tests. The Type A test is 
conducted at a containment pressure (Pt) not less than half of the 
peak pressure (0.5 Pa). It is performed once every 10 years. In 
France, containment leaktightness is continuously monitored during 
reactor operation in all of the French PWR plants using the SEXTEN 
system. It is also being evaluated by the Swedes for their PWR units. 
Leaks may be detected during the positive or negative pressure periods 
in the containment by evaluating the air mass balance in the 
containment. Type A tests are conducted at containment peak pressure 
(loss-of-coolant accident pressure) before initial plant startup, 
during the first refueling, and thereafter every 10 years unless a 
degradation in containment leaktightness is detected. In that case, 
tests are conducted more frequently.
    Further details of international approaches to containment testing 
are provided in NUREG-1493.

Advance Notices for Rulemaking

    Over time, it has become apparent that variations in plant design 
and operation frequently make it difficult to meet some of the 
requirements contained in Appendix J because of its prescriptive 
nature. Economic and occupational exposure costs are directly related 
to the frequency of containment testing. Containment integrated 
leakage-rate tests (Type A) preclude any other reactor maintenance 
activities and thus are on the critical path for return to service from 
reactor outages. In addition to the costs of the tests, integrated leak 
tests impose the added burden of the cost of replacement power. 
Containment-penetration leak tests (Type B and C) can be conducted 
during reactor shutdowns in parallel with other activities and thus 
tend to be less costly; however, the large number of penetrations 
impose a significant burden on the utilities. Additionally, risk 
assessments performed to date indicate that the allowable leakage rate 
from containments can be increased, and that control of containment 
leakage at the current low rates is not as risk significant as 
previously assumed.2 3

    \2\ ``Severe Accident Risks: An assessment for five U. S. 
Nuclear Power Plants, Final Summary Report.'' NUREG-1150, December 
1990. Copies of NUREGs may be purchased from the Superintendent of 
Documents, U.S. Government Printing Office, P. O. Box 37082, 
Washington, DC 20013/7082. Copies are also available from the 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161. A copy is available for inspection and/or 
copying in the NRC Public Document Room, 2120 L Street, NW. (Lower 
Level), Washington, DC.
    \3\ ``Performance-Based Containment Leak Test Program,'' NUREG-
1493, July 1995.
---------------------------------------------------------------------------

    In August of 1992, the NRC initiated a rulemaking to modify 
Appendix J to make it less prescriptive and more performance-oriented. 
The Commission also initiated a plan to relax the allowable containment 
leakage rate used to define performance standards for containment 
tests. In the Federal Register of January 27, 1993 (58 FR 6196), the 
NRC indicated the following potential modifications to Appendix J of 10 
CFR Part 50 would be considered:
    (1) Increase allowable containment leakage rates based on Safety 
Goals and PRA technology (i.e., define a new performance standard); and
    (2) Modify Appendix J to be a performance-based regulation:
    A. Limit the revised rule to a new regulatory objective. In order 
to ensure the availability of the containment during postulated 
accidents, licensees should either:
    (i) Test overall containment leakage at intervals not longer than 
every 10 years, and test pressure-containing or leakage-limiting 
boundaries and containment isolation valves on an interval based on the 
performance history of the equipment; or
    (ii) Provide on-line (i.e., continuous) monitoring of containment 
isolation status.
    B. Remove prescriptive requirements from Appendix J and preserve 
useful portions as guidance in an NRC regulatory guide.
    C. Endorse industry standards on:
    (i) Guidance for calculating plant-specific allowable leakage rates 
based on new NRC performance standards;
    (ii) Guidance on the conduct of containment tests; and
    (iii) Guidance for on-line monitoring of containment isolation 
status.
    D. Continue to accept compliance with the current detailed 
requirements in Appendix J (i.e., licensees presently in compliance 
with Appendix J will not need to do anything if they do not wish to 
change their practice). 

[[Page 49498]]

    A public workshop on the subject was held by the NRC on April 27 
and 28, 1993.4

    \4\ ``Workshop on Program for Elimination of Requirements 
Marginal to Safety,'' NUREG/CP-0129, September 1994.
---------------------------------------------------------------------------

February 1995 Proposed Revision

    Based on several advance notices for rulemaking and significant 
public comment and discussion, evaluation of risks and costs, and 
consideration of which modifications have become feasible and 
practical, in the February 21, 1995, Federal Register the NRC proposed 
two phases for modifications of requirements to containment leakage 
testing. The first phase allowed leakage-rate testing intervals to be 
based on the performance of the containment system structures and 
components. The second phase will further examine the needed 
requirements of the containment function (i.e. structural and leak-
tight integrity of containment system structures and components, and 
prevention of inadvertent bypass), and include consideration of the 
potential for on-line monitoring of containment integrity to verify 
certain functions. Public comments were solicited to guide this future 
work.
    The February 21, 1995, proposed rule applies to all NRC licensees 
who operate light-water-cooled power reactors. The proposed rule allows 
licensees the option of continuing to comply with the current Appendix 
J or to adopt the new performance-based standards.
    The NRC's analyses are based upon the insight gained through the 
use of probabilistic risk assessment techniques and the significant 
data base of practical, hands-on operating experience gained since 
Appendix J was promulgated in 1973. This operating experience provides 
solid evidence of the activities necessary to conduct Appendix J 
testing, and the costs of those activities both in monetary terms and 
occupational radiation exposure.
    The proposed rule is based on analytical efforts documented in 
NUREG-1493 which, like NUREG-1150, confirms previous observations of 
insensitivity of population risks from severe reactor accidents to 
containment leakage rates.
    The current Appendix J requirements continue to achieve the 
regulatory criterion of assuring an essentially leak-tight boundary 
between the power reactor system and the external environment (General 
Design Criterion 16). Costs associated with complying with current 
Appendix J requirements are estimated to be $165,000 for a complete 
battery of Type B/C tests and $1,890,000 for Type A tests. Over the 
average reactor's remaining lifetime of 20 years, the present value of 
all remaining containment leakage testing at a 5 percent discount rate 
is estimated to be about $7 million per reactor. Estimates of the 
remaining industry-wide costs of implementing current Appendix J 
requirements ranged from $720 to $1,080 million, approximately 75 
percent of which could be averted with a performance-based rule.
    The Regulatory Analysis for the proposed rule finds that by 
allowing requirements to remain in effect with marginal impact on 
safety, but which impose a significant cost on licensees, is to have 
missed an opportunity to improve regulatory coherence and to focus 
NRC's regulations to areas where the return in terms of added public 
safety is higher.
    Specific alternatives for modifying the current Appendix J were 
identified by the public in response to the NRC's Federal Register 
notice published on January 27, 1993 (58 FR 6196). Those whose 
characteristics matched the NRC's established criteria for the marginal 
to safety program were selected for further review.

Modifications of Advance NRC Proposal

Allowable Leakage Rate
    The NRC had initially planned to establish, by rulemaking, a risk-
based allowable leakage rate commensurate with its significance to 
total public risk. Specific findings from NUREG-1493 on the allowable 
leakage rate include:
    1. Allowable leakage could be increased approximately two orders of 
magnitude (100-200 fold) with marginal impact on population dose 
estimates from reactor accidents.
    2. Calculated risks to individuals are several orders of magnitude 
below the NRC's Safety Goals for all reactors considered.
    3. Increases in the allowable leakage rate are estimated to have a 
negligible impact on occupational exposure.
    Relaxing the allowable leakage rate is estimated to reduce future 
industry testing costs by $50 to $110 million, a 10 percent decrease in 
overall leakage-rate testing costs.
    A risk-based allowable leakage rate would be based on an 
evaluation, using PRA, of the sensitivity and significance of 
containment leakage to risk, and the determination of an appropriate 
containment leakage limit commensurate with its significance to the 
risk to the public and plant control-room operators. However, this 
would have entailed a major change in policy and restructuring of the 
current licensing basis and a more complete understanding of the 
uncertainties associated with the threat of severe accidents to the 
containment, and therefore, the NRC planned to develop a modification 
of the performance standard (allowable leakage level) in the second 
phase separate from modifications of testing requirements. This 
modification would be part of a broader effort to further examine the 
risk significance of various attributes of containment performance, 
i.e., structural and leak-tight integrity of containment-system 
structures and components, and inadvertent bypass.
On-Line Monitoring (OLM) Systems
    Currently, there is no NRC requirement for systems which 
continuously monitor the containment to detect unintentional breaches 
of containment integrity.
    Studies discussed in NUREG-1493, ``Performance-Based Containment 
Leak Test Program,'' found that, based on operating experience, OLM 
would not significantly reduce the risk to the public from nuclear 
plant operation and, thus, could not be justified solely on the basis 
of risk-based considerations. Specific findings include:
    1. Existing continuous monitoring methods appear technically 
capable of detecting leaks in reactor containments within 1 day to 
several weeks. OLM systems are in use or planned in several European 
countries and Canada.
    2. OLM systems are capable of detecting leaks only in systems that 
are open to the containment atmosphere during normal operation 
(approximately 10 percent of the mechanical penetrations).
    3. The technical and administrative objectives of OLM systems and 
Type A tests are different.
    4. OLM could not be considered as a complete replacement for Type A 
tests because it cannot challenge the structural and leak-tight 
integrity of the containment system at elevated pressures.
    5. Analysis of the history of operating experience indicated a 
limited need for, and benefit of, OLM in the U.S.
    Although OLM can not be justified solely based on risk 
considerations, a plant already possessing such a system has a greater 
assurance of achieving certain attributes of containment integrity. 
Therefore, OLM systems could contribute towards an overall leakage-
monitoring scheme. Some capability for on-line monitoring already 
exists as a byproduct of specific containment designs. For example, 
licensees with 

[[Page 49499]]
inerted BWR containments, or subatmospheric PWR containments, could 
possibly detect gross leakages that develop during normal operation.
    Given that the application of on-line monitoring is specific to 
containment design, and generic application can not be justified solely 
on risk considerations, the NRC did not propose a requirement for OLMs. 
However, licensees with such a capability (e.g. inerted BWR 
containments, and subatmospheric PWR containments) were encouraged to 
propose plant-specific application of such a capability, and to take 
credit for any added assurance of containment integrity provided by 
such a system compared to other testing methods. The NRC proposed to 
reconsider the role of OLM in the second phase of modifications in this 
area along with the allowable leakage rate.

Proposed Modification of Type A, B, and C Test Intervals

    In the February 1995 proposed rule, the NRC proposed a new risk-
based regulation based on the performance history of components 
(containment, penetrations, valves) as the means to justify an increase 
in the interval for Type A, B, and C tests. The revised regulation 
requires tests to be conducted on an interval based on the performance 
of the containment structure, penetrations and valves without 
specifying the interval in the regulation. Currently, three Type A 
tests are conducted in every 10 year period. Type B (except airlocks, 
which are tested more frequently) and C tests are conducted on a 
frequency not to exceed 2 years.
    The NRC proposed to base the frequency of Type A tests (ILRTs) on 
the historical performance of the overall containment system. Specific 
findings documented in NUREG-1493 that justify the proposal include:
    1. The fraction of leakages detected only by ILRTs is small, on the 
order of a few percent.
    2. Reducing the frequency of ILRT testing from 3 every 10 years to 
1 every 10 years leads to a marginal increase in risk.
    3. ILRTs also test the strength of the containment structure. No 
alternative to ILRTs has been identified to provide assurance that the 
containment structure would meet allowable leakage rates during design-
basis accidents.
    4. At a frequency of 1 test every 10 years, industry-wide 
occupational exposure would be reduced by 0.087 person-sievert (8.7 
person-rem) per year.
    Based on specific, detailed analyses of data from the North Anna 
and Grand Gulf nuclear power plants, and data from twenty-two nuclear 
plants (see NUREG-1493), performance-based alternatives to current LLRT 
methods are feasible with marginal impact on risk. Specific findings 
include:
    1. Type B and C tests are capable of detecting over 97 percent of 
containment leakages.
    2. Of the 97 percent, virtually all leakages are identified by 
LLRTs of containment isolation valves (Type C tests).
    3. Based on the detailed evaluation of the experience of a single 
two-unit station, no correlation of failures with type of valve or 
plant service could be found.
    4. For the 20 years of remaining operations, changing the Type B/C 
test frequency to once every 5 years for good-performing components is 
estimated to reduce industry-wide occupational radiation exposure by 
0.72 person-sievert (72 person-rem) per year. If 20-year license 
extension is assumed, the estimate is 0.75 person-sievert (75 person-
rem) per year.
    Future industry testing costs are reduced by approximately $330 to 
$660 million if ILRT tests are conducted once every 10 years rather 
than the current 3 per 10 years. ILRT savings represent about 65 
percent of the remaining costs of current Appendix J requirements. 
Performance-based LLRT alternatives are estimated to reduce future 
industry testing costs by $40 million to $55 million. LLRT savings 
represent about 5 percent of the total remaining costs of Appendix J 
testing.
    Therefore, based on the risks and costs evaluated, and other 
considerations discussed above, a performance-based Appendix J was 
proposed which encompassed the following principles, which differ 
moderately from those first described in the Federal Register (January 
27, 1993 58 FR 6197).
    General (1) Make Appendix J less prescriptive and more performance-
oriented; (2) Move details of Appendix J tests to a regulatory guide as 
guidance; (3) Endorse in a regulatory guide the industry guideline (NEI 
94-01) on the conduct of containment tests (The methods for testing are 
contained in an industry standard (ANSI/ANS 56.8-1994) which is 
referenced in the NEI guideline); and (4) Allow voluntary adoption of 
the new regulation, i.e., current detailed requirements in Appendix J 
will continue to be acceptable for compliance with the modified rule.
    Leakage Limits Acknowledge the less risk-significant nature of 
allowable containment leakage but pursue its modification as a separate 
action.
    Type A Test Interval (1) Based on the limited value of integrated 
leakage-rate tests (ILRTs) in detecting significant leakages from 
penetrations and isolation valves, establish the test interval based on 
the performance of the containment system structure; (2) The 
performance criterion of the test will continue to be the allowable 
leakage rate (La); (3) The industry guideline allows extension of the 
Type A test interval to once every 10 years based on satisfactory 
performance of two previous tests, inclusive of the pre-operational 
ILRT; (4) In the regulatory guide, the NRC takes exception to industry 
guidance for the extension of the interval of the general visual 
inspection of the containment system, and limits the interval to 3 
times every 10 years, in accordance with current practice.
    Type B & C Test Interval (1) Allow local leakage-rate test (LLRTs) 
intervals to be established based on the performance history of each 
component; (2) The performance criterion for the tests will continue to 
be the allowable leakage rate (La); (3) Specific performance factors 
for establishing extended test intervals (up to 10 years for Type B 
components, and 5 years for Type C components) are contained in the 
regulatory guide and industry guideline. In the regulatory guide, the 
NRC has taken exception to the NEI guideline allowing the extension of 
Type C test intervals up to 10 years, and limits such extensions to 5 
years.

Summary of Public Comments

    Twenty-six letters were received that addressed the policy, 
technical, and cost aspects of the proposed rulemaking, including the 
nine questions posed by the NRC in the February 21, 1995 proposed rule. 
All comments, including the ones received by the NRC after the deadline 
were considered. The commenters included 4 private citizens, 1 public 
interest group, 18 utilities, 1 nuclear utility industry group, 1 State 
regulatory agency, and 1 foreign regulator.
    Although the proposed rule did not generate a significant number of 
public comments, the commenters did align themselves into two distinct 
groups: those who supported publishing the rule and those against. 
Those who supported publishing the rule comprise the vast majority of 
the commenters (22) and included the Nuclear Energy Institute (NEI), 
which represents the nuclear utility licensees, eighteen individual 
nuclear power plant licensee respondents, a Spanish regulatory 
authority and two private citizens (Mr. 

[[Page 49500]]
Hill and Mr. Barkley). This group is very supportive of the 
Commission's risk-based regulatory program, and supports proceeding 
with the rule in an expeditious manner, despite having reservations 
about three specific provisions. The issues of most concern to this 
group are: (1) Licensee commitments to certain requirements of the 
regulatory guide implementing Appendix J testing via use of the 
technical specifications (industry would prefer using a plant's final 
safety analysis report); (2) requirements to conduct visual internal 
and external inspections of the containment on a frequency of 3 times 
per 10 years (industry would prefer once per 10 years to coincide with 
Type A tests); (3) making Option B of the proposed rule mandatory 
(industry would prefer to retain the optional feature); and (4) Type C 
test frequency (industry would prefer a 10-year test interval for 
certain Type C valves). Industry supports a future rulemaking to 
increase the allowable leakage rate.
    Two private citizens (Mr. Arndt and Dr. Reytblatt) are opposed to 
the proposed rule. The issues of most concern to these citizens are: 
(1) Type A test frequency (Mr. Arndt would prefer that frequencies be 
held at current levels); (2) Type A test methodology (Dr. Reytblatt 
wants to halt Type A testing until the test accuracy is improved); (3) 
Type C test frequencies (Mr. Arndt believes the existing database does 
not support 10-year test intervals, and suggests 5-years as an upper 
limit at the present time); and (4) Leakage rate (a future rulemaking 
to increase the allowable leakage rate should not be undertaken).
    Two organizations are opposed to the proposed rule. The Bureau of 
Nuclear Engineering of the state of New Jersey and the Ohio Citizens 
for Responsible Energy (OCRE, represented by Ms. Hiatt), a public 
interest group, expressed skepticism in the risk-based approach to 
regulation as embodied in the philosophy of the Marginal-to-Safety 
Program. The issues of most concern to this group are that: (1) 
Increases in public risk are not acceptable, no matter how marginal; 
and (2) A future rulemaking to increase the allowable leakage rate 
should not be undertaken.
    NRC Position. With respect to the areas of disagreement between the 
NRC and those who generally support the proposed rule, no new 
information has been provided in the public comments that was not 
already addressed in ongoing dialogue. Accordingly, the NRC has not 
made any substantive changes to its proposed regulation. Specifically, 
the NRC has retained: (1) Its position of requiring the use of 
technical specifications; (2) The intervals established for visual 
examinations of containment; and (3) The 5-year Type C test interval.
    With respect to the optional feature of the rule, the NRC agrees 
with the industry and has retained this feature. With respect to Mr. 
Arndt and Dr. Reytblatt, the NRC agrees in part with Mr. Arndt and has 
decided not to alter the LLRT test interval as noted in item (3). The 
other issues raised by Mr. Arndt and Dr. Reytblatt contain no 
information that has not been considered previously in a public forum. 
Therefore, the NRC has decided to make no substantive changes to its 
proposed rule as a result of the issues raised. With respect to the two 
organizations opposed to the proposed rule (OCRE and the NJ Bureau of 
Nuclear Engineering), neither has provided new information or a 
compelling reason to abandon the risk-based approach to regulation.
    In its preliminary criteria for developing performance-based 
regulations, the NRC identified several issues to be addressed by the 
rulemaking process as a measure of the viability of the revised rule. 
These issues were addressed in the proposed rule and the NRC sought 
further public input on them. Comments were received on these topics in 
addition to other areas of interest to the public. The following is a 
summary of comments received on these issues and areas, and NRC's 
response. A complete discussion of all comments is included in the 
Public Comment Resolution Document.5

    \5\ Copies are available for inspection or copying for a fee 
from the NRC Public Document Room at 2120 L Street NW., Washington, 
DC; the PDR's mailing address is Mail Stop LL-6, Washington, DC 
20555; telephone (202) 634-3273; fax (202) 634-3343.
---------------------------------------------------------------------------

    1. Can the new rule and its implementation yield an equivalent 
level of, or would it only have a marginal impact on safety?
    Twenty-four commenters addressed this issue, offering a wide 
variety of opinions. Twenty commenters believe that implementation of 
the proposed rule will provide an equivalent level of safety to that 
provided by the current rule. A majority of commenters, representing 
for the most part nuclear utilities, believe that the proposed 
regulation will reduce the testing burden currently imposed on the 
nuclear industry, and will result in more efficient use of utility 
resources, while ensuring the health and safety of the public. They 
believe that the practical experience gained from more than 1,500 
reactor-years of commercial nuclear power-plant operation provides an 
appropriate basis to adjust the Appendix J testing intervals which were 
established over 20 years ago on the basis of engineering judgment. 
Further, these commenters believe that a significant reduction in 
occupational exposures can be achieved with reduced testing frequency.
    Mr. E. Gunter Arndt, a private citizen, believes that the NRC has 
neither sufficient objective data nor perspective to justify increasing 
containment leakage rates, decreasing test frequencies, relaxing 
testing criteria, and reducing containment-system maintenance 
standards. Dr. Reytblatt, a private citizen, believes that Type A 
testing must be immediately suspended because the current testing 
methodology is flawed. Mr. Kent W. Tosch, Manager of New Jersey's 
Bureau of Nuclear Engineering, points out that the containment is an 
extremely important barrier to a release of radioactivity, but the 
philosophy reflected in this rulemaking is that this barrier can be 
allowed to become less reliable, even when some nuclear plants are 
showing signs of aging. Ms. Susan L. Hiatt, Director of Ohio Citizens 
for Responsible Energy, notes that relaxing the frequency of Appendix J 
tests leads to an increase in overall reactor risk of approximately 2 
percent and, while the NRC may deem this to be marginal, it nonetheless 
is an increase in risk.
    The NRC believes it has collected sufficient subjective and 
independent data to conduct its risk analysis. Detailed data from two 
independent power plants, representing four units, data supplied by the 
NEI representing approximately 30 additional units, and approximately 
180 ILRT and licensee event reports were analyzed. These data produced 
consistent results. Dr. Reytblatt's views, while technically correct, 
have been opposed by several technically competent organizations 
including the American National Standards Institute, and Oak Ridge 
National Laboratory because the improvements he suggests will have an 
insignificant effect on measured containment leakage rates in practice 
and thus have no safety significance. The NRC believes there has been 
ample opportunity for public discussion of the basis for the Appendix J 
revisions.
    Based on the foregoing, the NRC reaffirms its prior conclusion 
(stated in the February 21, 1995, Federal Register notice) that its 
safety objective for containment integrity can be maintained while at 
the same time reducing the burden on licensees. Additionally, the final 
rule provides a greater level of worker safety than that provided by 
the previous rule. 

[[Page 49501]]

    2. Can the regulatory/safety objective (qualitative or 
quantitative) be established in an objective manner to allow a common 
understanding between licensees and the NRC on how the performance or 
results will be measured or judged?
    To avoid repetition, the NRC incorporated responses to this 
question with those of Question 3.
    3. Can the regulation and implementation documents be developed in 
such a manner that they can be objectively and consistently inspected 
and enforced against?
    Approximately 20 commenters expressed opinions on Questions #2 and 
#3. The majority of the commenters believe that regulatory/safety 
objectives can be established objectively, and can be consistently 
enforced, although opinions differ on the optimum enforcement 
mechanism. Mr. Fernando Robledo of the Spanish nuclear regulatory 
agency states that the use of probabilistic risk assessment in the 
regulatory process provides a more realistic and objective assessment 
of nuclear safety, and thus supports its increased use in the 
regulatory process. The NEI believes the use of technical 
specifications for inspection and enforcement is neither necessary nor 
warranted and that, rather than a licensee commitment in the plant 
technical specification, future licensee commitments to implement 
Option B should be provided by documentation in the updated Final 
Safety Analysis Report.
    To assist in the common understanding of new methods of 
establishing Type A, B, and C test frequencies between the NRC and 
power reactor licensees, the NRC has had ongoing discussions with 
licensees. These discussions included participation in workshops 
designed to elicit a common understanding. Also, the NRC wishes to 
retain the current practice which requires its review and approval of 
changes to Appendix J performance limits and surveillance requirements. 
Therefore, the NRC has required that the regulatory guide should be 
specified in the technical specifications, an approach not inconsistent 
with the Commission's policy on technical specifications.
    Based on the foregoing, the NRC reaffirms its prior conclusion 
(stated in the February 21, 1995, proposed rule) that it expects that 
its activities to date, the review and endorsement of a industry 
guideline in a regulatory guide, and the general reference of the 
regulatory guide in plant technical specifications, will provide a 
common understanding on the measures of compliance.
    4. Should the proposed revision be made even less prescriptive?
    Except for Mr. Hill and Mr. Barkley, commenters did not explicitly 
address this question, which was directed at the possibility of 
reducing, even further, the testing frequency of ILRTs based on the 
fact that there does seem to be a strong statistical link between 
passing or failing successive ILRTs. Mr. Hill believes that there is no 
need to make the rule less prescriptive, and it may be inferred that is 
no desire on the part of industry to further increase the testing 
interval between ILRTs or to eliminate them completely. Richard 
Barkley, although strongly supporting an adjustment to the frequency of 
Type A testing to once every 10 years, also discourages the NRC from 
adopting a Type A surveillance interval any longer than 10 years 
because of aging considerations.
    The NRC has decided, in general, to maintain the present level of 
prescriptiveness in the proposed rule and, in particular, to not 
decrease further the test frequency for ILRTs. The NRC's position is 
guided by the desire to maintain some conservatism to address 
uncertainties and adopt an evolutionary approach wherein incentives 
remain for good performance.
    5. Should the proposed revisions be made mandatory?
    To avoid repetition, the NRC incorporated responses to this 
question with those of Question 7.
    6. Was the definition of ``backfit'' in Sec. 50.109(a)(1) intended 
to encompass rulemakings of the type represented by this proposed rule?
    To avoid repetition, the NRC incorporated responses to this 
question with those of Question 7.
    7. Is it appropriate for the Commission to waive the applicability 
of the Backfit Rule?
    The majority of the 20 commenters believe that compliance with the 
performance-based Appendix J program should not be made mandatory. The 
NEI believes that rulemakings that provide relief from a current 
regulation but would also contain one or more new requirements (as is 
the case here) would be subject to the backfit rule. These commenters 
believe that application of the backfit rule would be necessary before 
the NRC could promulgate the performance-based Appendix J program as a 
requirement, believing some licensees might select, for reasons of 
cost, to continue to comply with the existing Appendix J.
    The majority of commenters believe that the backfit rule would 
apply and should not be waived. Several utilities have no objection to 
waiving a backfit analysis when clear relief is available, but are 
concerned with the generic implications of waiving the applicability of 
the backfit rule. The NEI believes that while the proposed Appendix J 
revisions would provide much needed performance-based improvements to 
the existing Appendix J, it would also impose new requirements; thus, 
the proposed rule constitutes a backfit. Further, this commenter 
believes that, as a matter of administrative law, an agency lacks 
authority to depart from its own rules, thus, it cannot waive its own 
regulations.
    The NRC believes that if the rule were made mandatory, all 
licensees would incur costs setting up the procedures for implementing 
the rule's requirements following the guidance provided in the 
regulatory guide and the NEI guidance document. For those utilities 
whose circumstances (e.g., remaining plant life) would lead them to 
follow the current Appendix J, costs would be incurred with no 
additional benefit. Thus, the NRC agrees with the opinions expressed by 
the NEI and has decided to retain the proposed rule in its present 
form, which provides a non-mandatory alternative to the current 
Appendix J requirements. Because the NRC has decided to retain the 
optional feature of the proposed rule, the question of backfit is not 
addressed.
    8. Should NRC pursue a fundamental modification of its regulations 
in this area by establishing an allowable leakage rate based on risk 
analysis (as presented in draft NUREG-1493, Chapter 5), as compared to 
the current practice of using deterministic design basis accidents and 
dose guidelines contained in 10 CFR Part 100; or should the NRC modify 
the allowable leakage rate within the current licensing basis by 
revising source terms and updating regulatory guides (R.G.s 1.3 and 
1.4) 6 for calculating doses to the public? What are the 
advantages and disadvantages of the two approaches? What are some other 
considerations than risk to public, e.g., plant control room 
habitability, that might limit the allowable leakage rate?

    \6\ Copies may be purchased at current rates from the 
Superintendent of Documents, U.S. Government Printing Office, P.O. 
Box 37082, Washington, DC 20402-9328 (telephone 202-512-2249 or 202-
512-2171); or from the National Technical Information Service by 
writing NTIS at Port Royal Road, Springfield, VA 22161.
---------------------------------------------------------------------------

    The 20 commenters who responded to this question consist 
predominantly of the utilities endorsing the NEI position. These 
respondents encourages the NRC 

[[Page 49502]]
to pursue a rulemaking to alter allowable leakage rates using risk-
based analysis, believing that a firm technical basis exists for 
relaxing leakage rates up to two orders of magnitude with only a 
marginal impact on population risk estimates. It was also suggested 
that a review of the present source terms, dose projection models, and 
associated assumptions against the revised source terms and dose 
methodologies should also be performed to determine if relief can be 
achieved while assuring public health and safety. Three commenters 
discouraged the NRC from relaxing containment leakage rates ranging 
from the opinion that little benefit would result (Mr. E. Gunter Arndt) 
to an unequivocal belief that such a move would violate a plant's 
licensing basis by eliminating the protection provided for the nearest 
public individual by the 10 CFR Part 100 siting criteria (Ms. S. 
Hiatt). Ms. Susan Hiatt, representing the Ohio Citizens for Responsible 
Energy, believes that containment leak rates should be periodically 
reexamined, not for the purpose of relaxing them, but to determine 
whether they should be made more stringent given increasing population 
density around operating nuclear power plants.
    The NRC has decided to continue to pursue further reductions in 
regulatory burden with marginal impacts on safety and will address the 
complexities noted in the public comments in its future efforts to 
relax the allowable leakage rate.
    9. If the allowable leakage rate is increased, could on-line 
monitoring of containment integrity replace other current containment 
tests? Could the results of the on-line monitoring be used to establish 
a new performance basis for containment integrity involving less 
stringent reporting requirements if there is high assurance there are 
no large leakage paths in containment (> 1 in. diameter).
    The 18 commenters who responded to this question consist of the NEI 
and the utilities endorsing the NEI position, and Mr. Richard Barkley. 
The commenters do not believe that on-line monitoring (OLM) of 
containment integrity can replace many of the current containment 
tests, and state that OLM systems have very limited abilities to 
identify breaches in containment integrity. In the experience of Mr. 
Barkley, such systems add unnecessary plant complexity and cost.
    The NRC acknowledges the public comments rendered and will be 
guided by them in decisions yet to be made regarding the Phase 2 
effort.
    10. Are there any other regulatory approaches and technical methods 
by which the NRC can adopt a complete performance and risk basis to its 
regulations for containment leak-tight integrity? What are some of the 
attributes for performance, and what risk-based methods can be used to 
analyze these attributes?
    The NEI, speaking for all other utilities, addressed this question 
by stating that it had not conducted any analyses to determine whether 
any other regulatory approaches and technical methods by which the NRC 
can adopt a complete performance and risk basis to its regulations for 
containment leak-tight integrity.
    11. Rulemaking Documents.
    Seventeen commenters expressed opinions about NRC's regulatory 
policy decisions and/or specific language in the rule or its supporting 
documents. Mr. Hill believes that the NRC's and the NEI's guidance 
documents are not developed to the point of establishing a common 
understanding of how to meet NRC's regulatory and safety objectives 
(e.g., while NEI 94-01 contains a lot of information and solid 
guidance, it also contains inconsistencies, contradictions and unclear 
passages). The NEI, whose comments were endorsed by most responding 
licensees, proposed modifications to several of the rulemaking 
documents, including the Federal Register notice and its own guidance 
document.
    The NRC has amended its rule and accepts most of the revisions to 
the implementing documents to clarify language and achieve consistency 
between the rulemaking documents.
    12. Technical Issues.

Testing Frequency

    Twenty-four commenters expressed opinions on test frequency, the 
majority were supportive of 10-year intervals for both Types A, B and C 
tests. Regarding ILRTs, the Nuclear Energy Institute, several 
individual utilities, and Mr. Howard Hill expressed views that the 
proposed rule provides an acceptable testing frequency for ILRTs. Mr. 
Fernando Robledo, of the Spanish nuclear regulatory agency, believes 
that 10 years is too long a time interval between Type A containment 
tests. Mr. E. Gunter Arndt's view is that a preoperational test should 
not count as one of the two successful ILRT tests required to go to a 
10-year test interval because preoperational conditions are not at all 
representative of operating conditions. The citizens' group, Ohio 
Citizens for Responsible Energy, believes the frequency of containment 
leak-rate testing should remain unchanged from the current practice.
    Several commenters also expressed opinions on the NRC's position on 
LLRT testing frequency. Mr. Fernando Robledo, while agreeing in general 
with the test frequency for type B and C tests proposed in the draft 
regulatory guide, believes that certain mechanical penetrations 
particularly important for plant safety should be leak tested every 24 
months. Mr. E. Gunter Arndt's view is that the testing history of 
penetrations, and especially of valves, does not support leaving them 
untested for 10 years and suggested that an upper limit should be once 
every 5 years. One utility in particular, and the Nuclear Energy 
Institute in general believe that the NRC does not go far enough in 
citing that several sets of data justify 10-year LLRT intervals. In 
contrast, Mr. Richard Barkley, who also endorses Type B & C testing 
frequency based on performance, strongly supports the NRC's proposal to 
prohibit the adoption of Type C surveillance intervals longer than 60 
months.
    In establishing the 5-year test interval for LLRTs, the NRC has 
designed a cautious, evolutionary approach as data are compiled to 
minimize the uncertainty now believed to exist with respect to LLRT 
data. The NRC's judgment, based on risk assessment and deterministic 
analysis, continues to be that the limited database on unquantified 
leakages and common mode and repetitive failures introduces significant 
uncertainties into the probabilistic risk analysis. The NRC will be 
open to submittals from licensees as more performance-based data are 
developed. The extension of LLRT test interval to 5 years is a prudent 
first step. By allowing a 25 percent margin in testing frequency 
requirements, the NRC has provided the flexibility to accommodate 
longer fuel cycles. With respect to the 10-year interval for ILRTs, the 
NRC believes its technical support document (NUREG-1493) is persuasive 
by demonstrating that testing intervals could be increased up to once 
every 20 years with an imperceptible increase in risk, using actual 
ILRT data which accounted for random and plant-specific failures and 
plant aging effects.
    Based on the foregoing discussion, the NRC has decided to retain 
the 60-month Type C test interval and the 120-month interval for Type A 
and B tests. In response to public comments, the NRC has revised the 
regulatory guide to limit the extension of test intervals for main 
steam and feedwater isolation valves in BWRs, and containment purge and 
vent valves in PWRs and BWRs beyond 30 months given their operating 
experience and/or safety significance.

[[Page 49503]]


Test Pressures

    Two commenters expressed opinions on the magnitude of the pressures 
used in conducting Type A leakage tests. Northern States Power Company 
believes that Type A testing at full pressure is unnecessary and 
believes that visual inspection coupled with a reduced pressure test 
will adequately assure that the containment structural members are 
leak-tight, especially since reduced pressure Type A tests are legally 
acceptable tests as prescribed in the current 10 CFR Part 50, Appendix 
J. Mr. E. Gunter Arndt states that while Type A tests performed at 
reduced pressure rather than peak accident pressure are economically 
advantageous to the industry, the results of these tests are not 
necessarily indicative of leakage rates during accidents.
    The NRC believes that extrapolating low pressure leakage-test 
results to full pressure leakage-test results has turned out to be 
unsuccessful. The NRC believes that the peak calculated accident 
pressure: (1) Is consistent with the typical practice for NRC staff 
evaluations of accident pressure for the first 24 hours in accordance 
with Regulatory Guides 1.3 and 1.4; (2) Provides at least a nominal 
check for gross leak paths which might exist at high test pressures, 
but not at low test pressures; and (3) Directly represents technical 
specification leakage-rate limits, and provides greater confidence in 
containment system leak-tight integrity.
    Based on the foregoing, the NRC has decided to retain the 
calculated design basis loss-of-coolant accident peak pressure as the 
ILRT test pressure.

Containment Inservice Visual Inspection

    Eighteen commenters expressed opinions on this issue. The NEI and 
most utilities oppose the NRC's proposal to require visual examination 
of containment be performed 3 times every 10 years. These commenters 
suggest that this issue be taken up in a parallel rulemaking.
    The NRC finds the industry's arguments for relaxing the frequency 
of containment visual inspections to be unpersuasive. Because the 
visual examination is not integral to the ILRT (i.e., may be performed 
independently) and because the NRC sees benefits to the early detection 
of unknown aging mechanisms which may be active, the NRC considers it 
prudent to conduct visual inspections on a frequency greater than the 
ILRT. Further, the NRC believes it is inappropriate to defer a 
requirement pertaining to containment structural integrity to an 
ongoing rulemaking to incorporate ASME Section XI, IWE and IWL until 
its form and substance is finalized.
    Based on the foregoing, the NRC has decided to retain its frequency 
for the inservice visual inspection.

Reporting Requirements

    Only one comment was received on this issue. Dr. Z. Reytblatt noted 
that the proposed rule's reporting requirements consist only of a cover 
letter to the NRC and suggested this is intended to conceal information 
from the public. Dr. Reytblatt suggests that utilities should be 
required to submit all computer files related to testing to the NRC 
immediately after the tests have been completed to prevent their 
alteration or destruction.
    It is not the intent of the NRC's reporting requirements to conceal 
information from the public; if tests fail, the information is required 
to be reported to the NRC, and the NRC will make such data available to 
the public. The NRC has decided to retain its reporting requirements as 
stated in the proposed rule.

Modifications to the Proposed Rule in Response to Public Comments

    The NRC has decided to amend its proposed rule and its implementing 
documents to clarify language. The NRC has concluded that its 
regulatory analysis and its technical support document, NUREG-1493, do 
not require corrections to its technical or cost analyses or its 
findings. Modifications to all documents will be restricted to 
clarifications and enhancements to assist in communications with the 
reader, specifically in areas discussed in the public comments.
    The proposed rule has been modified by changing ``Acceptance 
criteria'' to ``Performance criteria'' in Section II, Definitions, and 
various conforming text changes to reflect consistent use of that term. 
Other similar redundant terms in the proposed rule, e.g. goals, have 
been deleted to establish clear and concise language in the rule.
    Specific changes to the draft regulatory guide, Section C, 
Regulatory Position, include (1) in paragraph number 2, the inclusion 
of the rationale for denying the ``3 refueling cycle'' change requested 
in the public comments; (2) the inclusion of a new paragraph number 4, 
taking exception to the NEI Industry Guideline, Section 10.2.3.3, which 
provides guidance that an as-found Type C test or an alternative test 
or analysis (emphasis added) shall be performed prior to any 
maintenance, repair, modification, or adjustment activity if it could 
affect a valve's leak-tightness. ``Alternate test or analysis'' are not 
endorsed as appropriate substitutes for an as-found test, since the 
latter provides clear and objective evidence of performance of 
isolation components; and (3) limitation of the extension of test 
intervals for main steam and feedwater isolation valves in BWRs, and 
containment purge and vent valves in PWRs and BWRs beyond 30 months 
given their operating experience and/or safety significance.

Regulatory Guide; Issuance, Availability

    The Nuclear Regulatory Commission has issued a new guide in its 
Regulatory Guide Series. This series has been developed to describe and 
make available to the public such information as methods acceptable to 
the NRC staff for implementing specific parts of the Commission's 
regulations, techniques used by the staff in evaluating specific 
problems or postulated accidents, and data needed by the staff in its 
review of applications for permits and licenses.
    Regulatory Guide 1.163, ``Performance-Based Containment Leakage-
Test Program,'' endorses an industry standard which contains guidance 
on an acceptable performance-based leakage-test program, leakage rate 
test methods, procedures, and analyses that may be used to implement 
the final regulation published in this notice.
    Comments and suggestions in connection with items for inclusion in 
guides currently being developed or improvements in all published 
guides are encouraged at any time. Written comments may be submitted to 
the Rules Review and Directives Branch, Division of Freedom of 
Information and Publications Services, Office of Administration, U.S. 
Nuclear Regulatory Commission, Washington, DC 20555. The NRC staff's 
response to public comments received on the draft version of this guide 
(DG-1037, issued in February 1995) are available for inspection or 
copying for a fee in the NRC Public Document Room, 2120 L Street NW., 
Washington, DC.
    Regulatory guides are available for inspection at the Commission's 
Public Document Room, 2120 L Street NW., Washington, DC. Single copies 
of regulatory guides may be obtained free of charge by writing the 
Office of Administration, Attention: Distribution and Services Section, 
U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; or by 
fax at (301) 415-2260. Issued guides may also be purchased from the 
National Technical Information Service on a standing order basis. 
Details on this service may be 

[[Page 49504]]
obtained by writing NTIS, 5285 Port Royal Road, Springfield, VA 22161. 
Regulatory guides are not copyrighted, and Commission approval is not 
required to reproduce them.

Implementation

    The proposed Option B to Appendix J will become effective 30 days 
after publication. At any time thereafter, a licensee or applicant may 
notify the NRC of its desire to perform containment leakage-rate 
testing according to Option B. Accompanying this notification, a 
licensee must submit proposed technical specifications changes which 
would eliminate those technical specifications which implement the 
current rule and propose a new technical specification referencing the 
NRC regulatory guide or, if the licensee desires, an alternative 
implementation guidance. Implementation must await NRC review and 
approval of the licensee's proposal. The NRC anticipates that a generic 
communication will be issued shortly which will provide the 
implementation procedure to all power reactor licensees.

Finding of No Significant Environmental Impact: Availability

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
Subpart A of 10 CFR Part 51, that this rule, if adopted, would not be a 
major Federal action significantly affecting the quality of the human 
environment, and therefore an environmental impact statement is not 
required. There will be a marginal radiological environmental impact 
offsite, and the occupational exposure onsite is expected to decrease 
by about 0.8 person-rem per year of plant operation for plant personnel 
if licensees adopt the performance-based testing scheme provided in the 
revised regulation. Alternatives to issuing this revision of the 
regulation were considered. One alternative would also entail complex 
revisions to other NRC regulations and therefore the NRC has decided to 
pursue it separately in the future. A third alternative would add 
regulatory burden without a commensurate safety benefit and therefore 
was found not to be acceptable. The environmental assessment is 
available for inspection or copying for a fee in the NRC Public 
Document Room, 2120 L Street NW, (Lower Level), Washington, DC; the 
PDR's mailing address is Mail Stop LL-6, Washington, DC 20555; phone 
(202) 634-3273; fax (202) 634-3343.

Paperwork Reduction Act Statement

    This final rule amends information collection requirements that are 
subject to the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et 
seq.). These requirements were approved by the Office of Management and 
Budget, approval number 3150-0011.
    Because the rule will relax existing information collection 
requirements by providing an option to the existing requirements, the 
public burden for this collection of information is expected to be 
reduced by approximately 400 hours per licensee per year. This 
reduction includes the time required for reviewing instructions, 
searching existing data sources, gathering and maintaining the data 
needed and completing and reviewing the collection of information. Send 
comments regarding the estimated burden reduction or any aspect of this 
collection of information, including suggestions for reducing this 
burden, to the Information and Records Management Branch (T-6 F33), 
U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; and to 
the Desk Officer, Office of Information and Regulatory Affairs, NEOB-
10202, (3150-0011), Office of Management and Budget, Washington, DC 
20503.

Regulatory Analysis

    The Commission has prepared a final regulatory analysis on this 
regulation. The analysis examines the costs and benefits of the 
alternatives considered by the Commission. The analysis is available 
for inspection or copying for a fee in the NRC Public Document Room, 
2120 L Street NW, (Lower Level), Washington, DC; the PDR's mailing 
address is Mail Stop LL-6, Washington, DC 20555; phone (202) 634-3273; 
fax (202) 634-3343.

Regulatory Flexibility Certification

    In accordance with the Regulatory Flexibility Act of 1980, (5 
U.S.C. 605(b)), the Commission certifies that this rule will not, if 
promulgated, have a significant economic impact on a substantial number 
of small entities. This rule affects only the licensing and operation 
of nuclear power plants. The companies that own these plants do not 
fall within the scope of the definition of ``small entities'' set forth 
in the Regulatory Flexibility Act or the Size standard adopted by the 
NRC (10 CFR 2.810).

Backfit Analysis

    This final rule amends a current regulation by establishing 
alternative requirements which may be voluntarily adopted by licensees. 
Therefore, the final rule does not constitute a backfit as defined in 
10 CFR 50.109(a)(1). Therefore, a backfit analysis is not necessary.

List of Subjects in 10 CFR Part 50

    Antitrust, Classified information, Criminal penalties, Fire 
protection, Incorporation by reference, Intergovernmental relations, 
Nuclear power plants and reactors, Radiation protection, Reactor siting 
criteria, Reporting and recordkeeping requirements.

    For the reasons set out in the preamble and under the authority of 
the Atomic Energy Act of 1954, as amended, the Energy Reorganization 
Act of 1974, as amended, and 5 U.S.C. 552 and 553, the NRC is adopting 
the following amendments to 10 CFR Part 50.

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

    1. The authority citation for Part 50 is revised to read as 
follows:

    Authority: Secs. 102, 103, 104, 105, 161, 182, 183, 186, 189, 68 
Stat. 936, 937, 938, 948, 953, 954, 955, 956, as amended, sec. 234, 
83 Stat. 1244, as amended (42 U.S.C. 2132, 2133, 2134, 2135, 2201, 
2232, 2233, 2236, 2239, 2282); secs. 201, as amended, 202, 206, 88 
Stat. 1242, as amended, 1244 1246 (42 U.S.C. 5841, 5842, 5846).

    Section 50.7 also issued under Pub. L. 95-601, sec. 10, 92 Stat. 
2951, as amended by Pub. L. 102-486, sec. 2902, 106 Stat. 3123, (42 
U.S.C. 5851). Sections 50.10 also issued under secs. 101, 185, 68 
Stat. 936, 955, as amended (42 U.S.C. 2131, 2235); sec. 102, Pub. L. 
91-190, 83 Stat. 853 (42 U.S.C. 4332). Sections 50.13, 50.54(dd), 
and 50.103 also issued under sec. 108, 68 Stat. 939, as amended (42 
U.S.C. 2138). Sections 50.23, 50.35, 50.55, and 50.56 also issued 
under sec. 185, 68 Stat. 955 (42 U.S.C. 2235). Sections 50.33a, 
50.55a and Appendix Q also issued under sec. 102, Pub. L. 91-190, 83 
Stat. 853 (42 U.S.C. 4332). Sections 50.34 and 50.54 also issued 
under sec. 204, 88 Stat. 1245 (42 U.S.C. 5844). Sections 50.58, 
50.91, and 50.92 also issued under Pub. L. 97-415, 96 Stat. 2073 (42 
U.S.C. 2239). Section 50.78 also issued under sec. 122, 68 Stat. 939 
(42 U.S.C. 2152). Sections 50.80 50.81 also issued under sec. 184, 
68 Stat. 954, as amended (42 U.S.C. 2234). Appendix F also issued 
under sec. 187, 68 Stat. 955 (42 U.S.C. 2237).

    2. Appendix J to 10 CFR Part 50 is amended by adding the following 
language between the title and the Table of Contents and adding the 
language for Option B after Section V.B3.

Appendix J--Primary Reactor Containment Leakage Testing for Water-
Cooled Power Reactors

    This appendix includes two options, A and B, either of which can 
be chosen for meeting the requirements of this appendix. 

[[Page 49505]]


Option A--Prescriptive Requirements

* * * * *

Option B--Performance-Based Requirements

Table of Contents

I. Introduction.
II. Definitions.
III. Performance-based leakage-test requirements.
    A. Type A test.
    B. Type B and C tests.
IV. Recordkeeping.
V. Application.

I. Introduction

    One of the conditions required of all operating licenses for 
light-water-cooled power reactors as specified in Sec. 50.54(o) is 
that primary reactor containments meet the leakage-rate test 
requirements in either Option A or B of this appendix. These test 
requirements ensure that (a) leakage through these containments or 
systems and components penetrating these containments does not 
exceed allowable leakage rates specified in the Technical 
Specifications and (b) integrity of the containment structure is 
maintained during its service life. Option B of this appendix 
identifies the performance-based requirements and criteria for 
preoperational and subsequent periodic leakage-rate testing.3

    \3\ Specific guidance concerning a performance-based leakage-
test program, acceptable leakage-rate test methods, procedures, and 
analyses that may be used to implement these requirements and 
criteria are provided in Regulatory Guide 1.163, ``Performance-Based 
Containment Leak-Test Program.''
---------------------------------------------------------------------------

II. Definitions

    Performance criteria means the performance standards against 
which test results are to be compared for establishing the 
acceptability of the containment system as a leakage-limiting 
boundary.
    Containment system means the principal barrier, after the 
reactor coolant pressure boundary, to prevent the release of 
quantities of radioactive material that would have a significant 
radiological effect on the health of the public.
    Overall integrated leakage rate means the total leakage rate 
through all tested leakage paths, including containment welds, 
valves, fittings, and components that penetrate the containment 
system.
    La (percent/24 hours) means the maximum allowable leakage rate 
at pressure Pa as specified in the Technical Specifications.
    Pa (p.s.i.g) means the calculated peak containment internal 
pressure related to the design basis loss-of-coolant accident as 
specified in the Technical Specifications.

III. Performance-Based Leakage-Test Requirements

A. Type A Test

    Type A tests to measure the containment system overall 
integrated leakage rate must be conducted under conditions 
representing design basis loss-of-coolant accident containment peak 
pressure. A Type A test must be conducted (1) after the containment 
system has been completed and is ready for operation and (2) at a 
periodic interval based on the historical performance of the overall 
containment system as a barrier to fission product releases to 
reduce the risk from reactor accidents. A general visual inspection 
of the accessible interior and exterior surfaces of the containment 
system for structural deterioration which may affect the containment 
leak-tight integrity must be conducted prior to each test, and at a 
periodic interval between tests based on the performance of the 
containment system. The leakage rate must not exceed the allowable 
leakage rate (La) with margin, as specified in the Technical 
Specifications. The test results must be compared with previous 
results to examine the performance history of the overall 
containment system to limit leakage.

B. Type B and C Tests

    Type B pneumatic tests to detect and measure local leakage rates 
across pressure retaining, leakage-limiting boundaries, and Type C 
pneumatic tests to measure containment isolation valve leakage 
rates, must be conducted (1) prior to initial criticality, and (2) 
periodically thereafter at intervals based on the safety 
significance and historical performance of each boundary and 
isolation valve to ensure the integrity of the overall containment 
system as a barrier to fission product release to reduce the risk 
from reactor accidents. The performance-based testing program must 
contain a performance criterion for Type B and C tests, 
consideration of leakage-rate limits and factors that are indicative 
of or affect performance, when establishing test intervals, 
evaluations of performance of containment system components, and 
comparison to previous test results to examine the performance 
history of the overall containment system to limit leakage. The 
tests must demonstrate that the sum of the leakage rates at accident 
pressure of Type B tests, and pathway leakage rates from Type C 
tests, is less than the performance criterion (La) with margin, as 
specified in the Technical Specification.

IV. Recordkeeping

    The results of the preoperational and periodic Type A, B, and C 
tests must be documented to show that performance criteria for 
leakage have been met. The comparison to previous results of the 
performance of the overall containment system and of individual 
components within it must be documented to show that the test 
intervals established for the containment system and components 
within it are adequate. These records must be available for 
inspection at plant sites.
    If the test results exceed the performance criteria (La) as 
defined in the plant Technical Specifications, those exceedances 
must be assessed for Emergency Notification System reporting under 
Secs. 50.72 (b)(1)(ii) and Sec. 50.72 (b)(2)(i), and for a Licensee 
Event Report under Sec. 50.73 (a)(2)(ii).

V. Application

A. Applicability

    The requirements in either or both Option B, III.A for Type A 
tests, and Option B, III.B for Type B and C tests, may be adopted on 
a voluntary basis by an operating nuclear power reactor licensee as 
specified in Sec. 50.54 in substitution of the requirements for 
those tests contained in Option A of this appendix. If the 
requirements for tests in Option B, III.A or Option B, III.B are 
implemented, the recordkeeping requirements in Option B, IV for 
these tests must be substituted for the reporting requirements of 
these tests contained in Option A of this appendix.

B. Implementation

    1. Specific exemptions to Option A of this appendix that have 
been formally approved by the AEC or NRC, according to 10 CFR 50.12, 
are still applicable to Option B of this appendix if necessary, 
unless specifically revoked by the NRC.
    2. A licensee or applicant for an operating license may adopt 
Option B, or parts thereof, as specified in Section V.A of this 
Appendix, by submitting its implementation plan and request for 
revision to technical specifications (see paragraph B.3 below) to 
the Director of the Office of Nuclear Reactor Regulation.
    3. The regulatory guide or other implementation document used by 
a licensee, or applicant for an operating license, to develop a 
performance-based leakage-testing program must be included, by 
general reference, in the plant technical specifications. The 
submittal for technical specification revisions must contain 
justification, including supporting analyses, if the licensee 
chooses to deviate from methods approved by the Commission and 
endorsed in a regulatory guide.
    4. The detailed licensee programs for conducting testing under 
Option B must be available at the plant site for NRC inspection.

    Dated at Rockville, Maryland this 20th day of September, 1995.

    For the Nuclear Regulatory Commission.
John C. Hoyle,
Secretary of the Commission.
[FR Doc. 95-23803 Filed 9-25-95; 8:45 am]
BILLING CODE 7590-01-P