NUREG-1777

Regulatory Effectiveness

Assessment of Option B of

Appendix J

U.S. Nuclear Regulatory Commission

Office of Nuclear Regulatory Research

Washington, DC 20555-0001
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NUREG-1777

Regulatory Effectiveness

Assessment of Option B of

Appendix J

Manuscript Completed: November 2002

Date Published: August 2003

Prepared by

J.V. Kauffman

Division of Systems Analysis and Regulatory Effectiveness

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

Washington, DC 20555-0001
ABSTRACT

The Nuclear Regulatory Commission's Office of Nuclear Regulatory Research is reviewing

selected regulations to determine if they are achieving the desired results. This initiative is part

of an evolving program to make NRC activities and decisions more effective, efficient, and

realistic. The goal of this assessment is to determine whether the revised, performance-based,

risk-informed, voluntary Option B of 10 CFR 50, Appendix J, Primary Reactor Containment

Leakage Testing for Water-Cooled Power Reactors, was effective, and, if not, to make

appropriate recommendations.

The effectiveness of Option B was determined by comparing regulatory expectations to

outcomes. The assessment concluded that risk-informing Appendix J has been effective. The

revised Appendix J has been at least partially adopted by all currently operating nuclear power

plants. Its adoption has resulted in cost saving and burden reduction to licensees, while

maintaining safety. Note that this conclusion regarding maintenance of safety is based on

probabilistic risk assessment insights and the very limited failure data available since the

adoption of Option B by licensees. Occupational radiation exposure to workers has been

reduced by adoption of the revised Appendix J. However, with the reduced frequency of

Type A tests under Option B, it is likely that a degraded containment will not be identified as

quickly as under the original Appendix J. Required licensee inspections of containment

structural members limit the potential for significant degradation to remain undetected for

lengthy periods of time.

iii
TABLE OF CONTENTS

ABSTRACT ............................................. iii

EXECUTIVE SUMMARY . ............................................. vii

FOREWORD.............................................................. ix

ABBREVIATIONS .......................................................... xi

1 INTRODUCTION ........................................................ 1

2 BACKGROUND ........................................................ 1

2.1 General Background ............................................. 1

2.2 Original Appendix J Requirements ................................... 1

2.3 Impetus for Option B ................ ............................. 2

2.4 Revised Appendix J (Option B) .......... ........................... 4

2.5 Expected Results from the Revised Appendix J ......................... 4

3 REGULATORY ASSESSMENT ........................ 4

3.1 Impact on Testing Burden and Cost of Testing ......................... 5

3.2 Risk Impact .................................................... 5

3.3 Impact on Occupational Radiation Exposure ........................... 7

3.4 Summary of Appendix J Revision Expectations and Outcomes ..... ........ 7

4 CONCLUSION ........................................................ 8

5 REFERENCES ............. 8

v
EXECUTIVE SUMMARY-.'

As part of the' Nuclear Regulatory'Commission program toaddress regulatoryeffectiveness, the

Office of Nuclear Regulatory Research'(RES) is reviewing'selected regulations to determine if

they are achieving 'the desired results. SECY-97-1.80, uResponse'to Staff Requirements -

Memorandum of May 28,'1 997, Concerning Briefing on IPE Insight Report," August 6, 1997,

describes a plan for the RES staff to assess the effectiveness of several major safety issue'

resolution efforts or regulations. -

Reactor containments constitute one of the principal lines of defense'in the defense-in-depth

design philosophy embodied in the current generation of light water power reactors. Several

mechanisms can cause releases to the environment. These include gross failure of

containment due to the pressure forces resulting from an accident, containment base-mat

melt-through, failure of containment isolation systems, interfacing system loss-of-coolant

accidents, steam generator tube ruptures, and releases as a result of containment leakage.

The original Appendix J to Title 10 of the Code of Federal Regulations Part 50 (10 CFR 50),

Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, specifies

leakage testing requirements including the types of tests to be performed, testing frequencies,

acceptance criteria, and reporting requirements. Appendix J test frequencies were based on

conservative, engineering judgment. The maximum allowable leakage rate is calculated in

accordance with 10 CFR 100, Reactor Site Criteria, and is defined in each facility's Technical

Specifications. Typical values are 0.1 percent of containment air mass per day for pressurized

water reactors and 1.0 percent of containment air mass per day for boiling-water reactors.

Appendix J became effective on March 16, 1973.

In September 1995, NRC issued the revised Appendix J. NRC allowed increasing the intervals

of tests based on the performance history of the containment, penetrations, and valves.

Guidance for implementation of Option B was issued as Regulatory Guide 1.163, Performance

Based Containment Leak-Test Program." In Regulatory Guide 1.163, NRC stated the

regulatory position limiting extension of main steam and feedwater isolation valves in boilingwater reactors, and containment vent and purge valves to 30 months based on operating

experience and their importance. Option B was voluntary for licensees.

The goal of this assessment was to determine whether Option B of Appendix J was effective in

achieving its desired results. The expectations were established from objectives stated when

the rule was issued. In general, Appendix J was to be made less prescriptive and more

performance oriented with appropriate regulatory guidance or endorsement of industry

guidelines. Adoption of Option B was voluntary. For this evaluation, effectiveness was

evaluated by assessing the extent to which the benefits of the rule have been achieved, and the

rule's impact on safety. Essentially, regulatory expectations and outcomes were compared.

The results were obtained from reviews of documents and operating experience. This

evaluation considered four main expected outcomes from Option B: (1) opportunity for

reduction in occupational radiation exposure from leak rate testing; (2) only a marginal risk

increase; (3) opportunity for reduced testing burden resulting in more efficient use of utility

resources; and (4) opportunity for licensee cost savings.

* . - . . t _~~ . ~ ~~ 

vii
The assessment concluded that risk-informing Appendix J has been effective. The revised

Appendix J has been at least partially adopted by all currently operating nuclear power plants.'

Its adoption has resulted in cost savings and burden reduction to licensees, while maintaining

safety. Note that this conclusion regarding maintenance of safety is based on probabilistic risk

assessment insights and the very limited failure data available since the adoption of Option B

by licensees. Occupational radiation exposure to workers has been reduced by adoption of the

revised Appendix J. However, with the reduced frequency of Type A tests under Option B, it is

likely that a degraded containment will not be identified as quickly as under the original

Appendix J. Required licensee inspections of containment structural members limit the

potential for significant degradation to remain undetected for lengthy periods of time.

'Partial adoption as used in this report means that not all portions of this voluntary rule were

adopted by all licensees. The vast majority of plants have adopted all portions.

viii
FOREWORD

This report evaluates the effectiveness of the voluntary, Option B of Appendix J to Title 10 of

the Code of Federal Regulations Part 50, "Primary Reactor Containment Leakage Testing for

Water-Cooled Reactors." NRC issued the revised, risk-informed, Appendix J in September,

1995. NRC allowed increasing the intervals of tests based on the performance history of the

containment, penetrations, and valves. The effectiveness of Option B is assessed by

comparing regulatory expectations to outcomes in the areas of opportunities for occupational

radiation exposure reduction, risk impact, testing burden reduction, and licensee cost savings.

The report concludes that risk-informing Appendix J has been effective. The revised Appendix

J has been at least partially adopted by all currently operating nuclear power plants. Its

adoption has resulted in cost savings and burden reduction to licensees, while maintaining

safety. Occupational radiation exposure to workers has been reduced by the adoption of the

revised Appendix J. However, with the reduced frequency of Type A tests under Option B, it is

likely that a degraded containment will not be identified as quickly as under the original

Appendix J. Required licensee inspections of containment structural members limit the

potential for significant degradation to remain undetected for lengthy periods of time.

This report is consistent with the NRC strategic performance goals of maintaining safety;

increasing public confidence; and making NRC activities more effective, efficient, and realistic

as follows:

Maintaining safety -The study report confirms that safety was maintained with the

implementation of Option B. The reduction in occupational radiation exposure resulting from

Option B directly contributes to the safety of nuclear workers. If the study had found that safety

had not been maintained, appropriate recommendations would have been made.

Public confidence - Public confidence should be improved by confirming that implementation

of Option B resulted in maintaining safety while burden and costs to licensees (ultimately,

societal costs) and occupational radiation exposure were reduced.

Making NRC activities more effective, efficient, and realistic - The report compares the

regulatory expectations to outcomes to assess the effectiveness of this regulation in achieving

its goals and identify areas needing attention, if any. In this case, issuing a voluntary,

risk-informed regulation was successful.

Farouk Eltawila, Director

Division of Systems Analysis and Regulatory Effectiveness

Office of Nuclear Regulatory Research

ix
ABBREVIATIONS

BWR boiling-water reactor

CFR Code of Federal Regulations

EPRI Electric Power Research Institute

ILRT integrated leak rate test

INEEL Idaho National Engineering and Environmental Laboratory

LLRT local leak rate test

NRC Nuclear Regulatory Commission, U.S.

PRA probabilistic risk assessment

PWR pressurized-water reactor

RES Nuclear Regulatory Research, Office of (NRC)

xi
1 INTRODUCTION

As part of the Nuclear Regulatory Commission program to address regulatory effectiveness, the

Office of Nuclear Regulatory Research (RES) is reviewing selected regulations'to determine if

they are achieving the desired results. SECY-97-1 80,'Response to Staff Requirements

Memorandum of May 28, 1997, Concerning Briefing onIPE Insight Report," August 6, 1997'

(Ref. 1), describes a plan for the RES staff to assess the effectiveness of several major safety

issue resolution efforts or regulations.

The work described in this report is an assessment of the performance-based, risk-informed,

voluntary option B of Title 10 Code of Federal Regulations Part 50 (10 'CFR 50), Appendix J,'

'Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors." The final

rule for revision of Appendix J was published on'Septerber 26, 1995, in the Federal Register.

(60FR49495). Much of this'study is based onw6rk performed by NRC contractors at the Idaho

National Engineering and Environmental Laboratory (INEEL).

2 BACKGROUND

2.1 General Background

Reactor containments constitute oneof the principal lines of defense in the defense-in-depth

design philosophy embodied in the current generation of light water power reactors. Several

mechanisms can cause releases'to'the environment. 'These include gross failure of

containment due to the pressure forces resulting from an accident, containment base-mat

melt-through, failure of containment isolation systems, interfacing system loss-of-coolant

accidents, steam generator tube ruptures, and releases as a result of containment leakage.

2.2 Original Appendix J Requirements

10 CFR 50, Appendix A, General Design Criteria for Nuclear Power Plants, Criterion 16,

mandates that the primary containment provide an essentially leak-tight barrierto protect,,.-

against uncontrolled release of radioactivity to the environment following postulated accidents.

Appendix J to 10 CFR 50, uPrimary Reactor Containment Leakage Testing for Water-Cooled

Power Reactors," specifies leakage testing requirements including the types of tests to be

performed, testing frequencies, acceptance criteria, and reporting requirements. Appendix J

test frequencies were based on conservative, engineering judgment. The maximum allowable

leakage rate is calculated in accordance with 10 CFR 100, uReactor Site Criteria," and is

defined in each facility's Technical Specifications. -Typical values are 0.1 percent of: 

containment air mass per day for pressurized-water reactors (PWRs) and 1.0 percent of

containment air mass per day for boiling-water reactors (BWRs). Appendix J became effective

on March 16, 1973. - - . -

Three types of containment leakage tests are required by the original Appendix J: (1) Type A,

integrated (or overall) leakage rate tests (ILRTs), (2) Type B,. leakage tests of penetration seals,

gaskets, and expansion bellows, and (3) Type C, leakage tests of isolation valves of pipes

penetrating containment. Type B and C tests are often called local leak rate tests (LLRTs).
Type A tests are required to be performed three times every 10 years. The Type A test itself

usually does not last longer than 24 hours, however, other activities associated with the test

(visual inspection, instrument setup, system lineups, pressurization, pressure stabilization,

verification, and depressurization) require several days and significant personnel resources.

ILRTs significantly impact plant outages because maintenance and refueling activities are

restricted and no activities are allowed inside containment during the tests. ILRTs are usually a

critical path activity.

Type B and C tests (LLRTs) are required on all penetrations at least once every 2 years, except

for airlocks which are tested more frequently. LLRTs are required to determine the as found"

condition of penetrations and isolation valves and another test must be performed following

maintenance or repairs. Although labor intensive, LLRTs are usually not critical path. Each

LLRT takes about 1 to 8 hours to perform. The number of penetrations and containment

isolation valves varies, but the typical PWR has about 90 containment penetrations while the

typical BWR has about 175 penetrations (Ref. 2). The weighted average of all U.S. BWRs and

PWRs is 110 penetrations per plant (Reference 2).

2.3 Impetus for Option B

NRC initiated a program in 1984 to identify regulatory requirements with marginal importance to

safety (49FR39066). The goal was the elimination or modification of requirements where

burdens on licensees were not commensurate with the requirement's safety significance.

Under this program, licensees were surveyed and Appendix J requirements were identified as

imposing significant burdens while having only marginal importance to risk (Ref. 3). An NRC

staff survey also identified Appendix J as a candidate for modification.

Another impetus for changing Appendix J was the results from probabilistic risk assessments

(PRAs) and other studies. PRAs provided a broad technical basis for the revision of the original

Appendix J requirements. PRAs, beginning with WASH-1400, "Reactor Safety Study," 1975

(Ref. 4), have consistently shown that containment leakage is a relatively minor contributor to

overall plant risk.

Several PRA documents and other risk information or analyses supporting a voluntary, riskinformed option for Appendix J were reviewed. Some important results which support revision

of Appendix J include:

1986 NUREG/CR-4330, "Review of Light Water Reactor Regulatory Requirements"

(Reference 3).

Concluded that increasing allowable reactor containment leakage to 10 percent per day

would have minimal mpact on safety but would provide substantial savings. The effect

of containment leakage is small since risk is dominated by accident sequences that

result in failure or bypass of containment.

1988 NUREG-1273, 'Technical Findings and Regulatory Analysis for Generic Safety Issue

II.E.4.3 - Containment Integrity Check" April 1988 (Ref. 5).

2
Concluded that: (1) the leakages in about one third of reported events were

immediately detected and corrected, (i.e., posed minimal threat to containment

integrity), (2) about one sixth of reported events involved components in direct

containment-to-atmosphere leakage paths, and (3) 99 percent of leakage events were

detected by LLRTs.

1990 NUREG-l150, "Severe Accident Risk: An Assessment of Five U.S. Nuclear Power

Plants" Vols. 1 and 2, June 1989 and December 1990 (Ref. 6).

Used more advanced PRA techniques. Concluded that the overall levels of risk due to

containment leakage are less than previous studies because accident risks are,

dominated by scenarios where the containment fails or is bypassed. -A major finding is

that maintaining containment structural integrity post-accident is much more important

than containment leak tightness.

1997 NUREG-1560, Individual Plant Examination Program: Perspectives on Reactor Safety

and Plant Performance" December 1997 (Ref. 7).

Contains insights from Individual Plant Examinations, which were performed at all plants

using PRA techniques. Risk is dominated by containment failure and bypass following

severe accidents. Concludes that containment isolation failures are not important BWR -

contributors to risk, and that while the probability of isolation failures are relatively large

for some PWRs (primarily those with large, dry, and subatmospheric containments), the

leak area is usually small such that the failure does not contribute significantly to

radionuclide releases.- :- -

1994 Electric Power Research Institute (EPRI) TR-1 04285, "Risk Impact Assessment of

Revised Containment Leak Rate Testing Intervals" August 1994 (Ref. 8).

Showed that the risk associated with extension of containment leak rate testing

frequencies is insignificant.

1995 NUREG-1493, "Performance Based Containment Leak-Test Program" (Reference 2).

This was a detailed study of the impacts, costs, and risk of the original Appendix J

requirements and several alternatives including changing test intervals and allowable. 

leakage rates. Confirmed the insensitivity of population risks to low containment

leakage rates following an accident.

Also concluded that: (1) increasing allowable leakage rates by 10 to 100 times results in

a marginal risk increase,- while reducing costs by about 10 percent; (2) reducing Type A

tests to once per 10 years results in imperceptible risk increases, but substantially

reduces costs; (3) Type A tests rarely detect significant leakage, the majority of leakage

is detected by Type C tests; (4) Type B test frequencies (except airlocks) could be

reduced with no risk impact because there are very few Type B failures (except airlocks)

and test failures usually involve only small leaks; (5) based on past component

performance, Type C test frequencies could be reduced; and (6) reducing Type B and C

test frequencies could result in substantial cost savings (up to 58 percent).

3
2.4 Revised Appendix J (Option B)

In September 1995, NRC issued the revised Appendix J (60FR49495). In Option B and its

associated guidance documents, NRC allowed increasing the intervals of Type A, B, and C

tests based on the performance history of the containment, penetrations, and valves. The

maximum test interval for Type A tests was 10 years, but the requirement for three containment

visual inspections every 10 years was retained. All Type A tests were to be performed at Pa2

(rather than extrapolating the leakage from measurements taken at a lower pressure as allowed

by the original Appendix J). Type B tests (except for airlocks) would be required at least once

every 10 years. The 5 year maximum test interval for containment isolation valves (Type C)

was established due to uncertainties about Type C test data. Guidance for implementation of

Option B was issued as Regulatory Guide 1.163, "Performance Based Containment Leak-Test

Program" September 1995 (Ref. 9). In Regulatory Guide 1.163, NRC stated the regulatory

position limiting extension of testing of main steam and feedwater isolation valves in BWRs,

and containment vent and purge valves, to 30 months based on operating experience and their

importance. Option B was voluntary for licensees.

NRC decided to defer consideration of changes in allowable leakage rates to a second phase of

rulemaking. On-line monitoring of containment integrity could not be justified solely on risk

considerations and so was not proposed as a requirement. Containment visual inspection

requirements of Appendix J were retained, despite industry assertions that such inspections

were adequately addressed by ASME Section Xl Subsections IWE and IWL, because

rulemaking to incorporate these subsections into the regulations had not been finalized.

Twenty-six letters were received during the comment phase of rulemaking for Option B. Those

who supported the rule comprised the vast majority of the commenters (22), and included the

Nuclear Energy Institute, which represents the nuclear utility licensees, 18 individual nuclear

power plant license respondents, a Spanish regulatory authority and 2 private citizens. Two

private citizens and two organizations opposed the proposed rule. NRC did not make any

substantive changes to the proposed rule based on the comments received because the

comments did not contain new information that had not already been addressed in a public

forum.

2.5 Expected Results from the Revised Appendix J

NRC had four main expected results from Option B (60FR49495): (1) opportunity for reduced

occupational radiation exposure, (2) only a marginal risk increase, (3) opportunity for reduced

testing burden, and (4) opportunity for cost savings.

3 REGULATORY ASSESSMENT

For this assessment of the regulatory effectiveness of Option B, the following were reviewed

and evaluated: (1) history and purpose of Appendix J, (2) PRA documents and other risk

information or analyses supporting a voluntary risk-informed option for Appendix J (see

2 Pa is the calculated peak containment internal pressure related to the design basis accident.

4
Section 2.3), (3) history and expectations for Option B, (4) operating experience and reliability

data for containment valves and penetrations, and (5) data regarding voluntary adoption of

Option B (i.e., which plants adopted Option B and when it was adopted).

3.1 Impact on.Testing Burden and Cost of Testing I

A significant decrease in testing burden and cost were expected for those licensees which

adopted the revised Appendix J. Costs of Type A tests (ILRTs) were estimated (Reference 2).

The total cost for-an ILRT was estimated to be about $1.89 million per test- and included

equipment cost rentals, labor costs, and replacement power costs. Replacement power costs

are included because ILRTs are critical path and usually take from 3 to 5 days. With the

revised Appendix J. ILRTs are conducted at a periodic interval based on the performance of the

overall containment system. Costs were estimated to decrease by about 67 percent for

changing from three ILRTs every 10 years to one lLRT every 10 years.

Costs of LLRTs were also estimated (Reference 2). The costs for a full battery of Type B and

C tests for a typical light water reactor was estimated to be abo'ut $165,000, and included LLRT

crew labor and support from plant staff. To illustrate the potential costs savings with the revised

Appendix J, calculations were done which showed that the cost of LLRTs could be reduced by

58 percent. Elimination-of Type B electrical penetrations from the previous 2-year frequency

was estimated to'eliminate $25,000 of LLRT costs, and elimination of half of the Type C tests

was estimated to reduce LLRT costs by an additional $70,000, for a total savings of $95,000 or

58 percent of the costs for a typical complete battery of Type B/C tests. Actual savings are, of

course,' dependent on the actual performance histories of the components.' - - . . C* 

Burden reduction and cost savings to licensees have resulted from the adoption of the revised

Appendix J. All licensees have at least partially adopted the revised 'Appendix J, mainly- in 1996

and 1997. U.S. reactors broke the 80 percent capacity factor aver'age for the'first time in 1999,

and achieved capacity factors of 87 percent and 88 percent in 2000 and 2001, respectively

(Ref. 10). An important factor in this improvement was licensee success in limiting the length of

refueling outages. Refueling outages may be shortened when the amount of containment leak

rate testing is reduced by the adoption of the revised Appendix J. It was impractical fr this -

assessment to determine precisely the timing and the extent which testing aid costs have been'

reduced. As part of its contract, NEEL reviewed containment isolation valve leakage events as'

reported in the NRC's Sequence Coding and Search System and the Institute of Nuclear Power

Operations' Nuclear Plant Reliability'Data System and Equipment Performance and Information

Exchange databases. INEEL determined that testing may be deferred on the majority of valves

and that ILRTs would rarely be required more than once every 10 years: All licensees have at:

least adopted portions of the voluntary, revised Appendix J, demonstrating that the burden

reduction and cost savings opportunities are real, and are being realized by many licensees.

3.2 'Risk Impact 'i 

Several PRA documents that supported or provided the bases for revising Appendix J were

reviewed (see section 2.3). This review found that'

Containriment leakage is a small contributor to overall accident risk. At the lower end of

changes in leakage rates, any uncertainties associated with the'calculated leakage' -

5
contribution are minuscule in comparison with other uncertainties, (e.g., prediction of

containment failure mode probabilities and magnitudes of fission product source terms.)

The NUREG-1 150 results for PWRs predict significant probabilities of no containment

failure even in the event of core melt accidents. With the containments predicted to

remain intact, at the upper end of the leakage-rate ranges considered. i.e., 200-400

percent containment volume per day, containment leakage could lead to several-fold

increases in the predicted risk. The expected fission product source terms associated

with the large leakage-rate cases, considering all possible unit damage states and

accident progression bins, were substantially lower than those resulting from

containment failure or bypass. Thus, the uncertainties associated with assessing the

leakage contribution at the upper ends of the ranges considered would be lower than

those associated with other containment failure modes. (NUREG-1 493, page 9-1)

Type B and C testing can detect a very large fraction of containment leaks. Only a

small fraction (a few percent) of leaks can only be detected by integrated containment

leakage tests. An assessment of the risk significance of the leaks only detectable by

ILRT was not provided. (NUREG-1273, pg. 6)

Experience from leakage rate testing indicates that frequent Type B testing of electrical

penetrations is of limited usefulness. There have been very few Type B failures (except

airlocks) and the leakage rates associated with these failures are typically small.

(NUREG-1493, pg. 10-3)

In NUREG-1 150 (Reference 6), the calculated individual latent cancer fatality risk is

below the NRC's safety goal, for containment leakage up to 100 percent per day.

EPRI TR-1 04285, uRisk Impact Assessment of Revised Containment Leak Rate Testing

Intervals" (Reference 8), demonstrated that a small (less than 1 percent), but

insignificant, risk increase was associated with the containment leak rate testing

frequency reduction of Option B.

Trending of valve failures reported in Nuclear Plant Reliability Data System, Equipment

Performance and Information Exchange, and licensee event reports showed generally

improving performance (fewer failures per year). The limited data available since the adoption

of the revised Appendix J, when taken in conjunction with the larger database considered as

part of the revision to Appendix J, does not show a statistically significant change in the trend of

the number of failures per year. Since the performance of valves has not significantly changed,

the failure rates assumed in support of the revision to Appendix J were appropriate, and may be

conservative. Therefore, at most, only the expected marginal increase in risk has resulted from

adoption of the revised Appendix J. The effectiveness of the original Appendix J was not

assessed for this study. Because of the continued reduction in transient initiators, any risk

increase from adoption of the revised Appendix J is likely to be even less than was expected

when Option B was offered to licensees.

With the reduced frequency of Type A tests under Option B, it is likely that a degraded

containment will not be identified as quickly as under the original Appendix J. However,

required licensee inspections of containment structural members limit the potential for

significant degradation to remain undetected for lengthy periods of time. Because Option B is

performance-based, testing failures will result in adjustments to the testing frequencies.

6
3.3 Impact on Occupational Radiation Exposure

A significant reduction in occupational radiation exposure was expected for those licensees

which adopted the revised Appendix J. Staff estimated that at an ILRT frequency of one test

every 10 years, industry-wide occupational exposure would be reduced by 0.087 person-sievert

(8.7 person-rem) per year (Reference 2). Changing the Type B and C testing frequency to

once every 5 years was estimated to reduce industry-wide occupational radiation exposure by

about 0.72 person sievert (72 person-rem) per year. Therefore, the total expected reduction in

occupational radiation exposure was 0.807 person sievert (80.7 person-rem) per year.

As previously noted, all currently operating U.S. nuclear power plants have at least adopted

portions of the revised Appendix J, mainly in 1996 or 1997. Performance Indicator data

reported by licensees and available on the NRC's public website, show that industry-wide

collective radiation exposure decreased from 202 Rem per plant in Fiscal Year 1995 to,',-

122 Rem in Fiscal Year 2001, with the largest decrease coming in Fiscal Year 1998 (140 Rem

down from 176 Rem). Although these reductions cannot be attributed solely to the adoption of

the revised Appendix J, occupational exposure is directly related to the number of tests

performed. The biggest reduction coincides with the time period immediately following adoption

of the revised Appendix J by most plants, and the magnitude'of the decrease in occupational

radiation exposure corresponds with the expectations for the revised Appendix J. Therefore,

the revised Appendix J was successful in providing the opportunity to reduce occupational

radiation exposure.

3.4 Summary of Appendix J Revision Expectations and Outcomes

-- ' Summary of Appendix'J Revision Expectations and Outcomes '

Area Expected Result Actual Outcomes Observations

Cost Savings Opportunity for cost Analysis of reported valve failures Expectations Met*

savings (for indicate that testing may be deferred.

licensees) on the majority of valves and that

ILRTs would rarely be required

more than once every 10 years. ' _||

Less Prescriptive Opportunity to reduce 100% of licensees have, at least Expectations Met

Regulation current testing partially, voluntarily adopted. See

burden; more efficient also cost savings.

use of utility

resources. See also

cost savings. -

Risk Impact Marginal Increase All studies indicate that the risk 'Expectations Met

impact to the public is not significant ||

Occupational Opportunity to reduce Occupational radiation exposure is Expectations Met

Exposure occupational radiation directly related to the number of

exposure tests performed. The number of ___________________ tests performed is reduced.

*although unquantified, the revision has been at least partially adopted by all licensees and has allowed licensees to

reduce testing costs and occupational exposure, thus expectations are met.

7
4 CONCLUSION

Risk-informing Appendix J has been effective. The revised Appendix J has been at least

partially adopted by all currently operating nuclear power plants. Its adoption has resulted in

cost saving, burden reduction, and reduced occupational radiation exposure while having an

insignificant impact on risk, and demonstrates the potential for further successes in riskinforming regulations.

5 REFERENCES

1. U.S. Nuclear Regulatory Commission, "Response to Staff Requirements Memorandum

of May 28, 1997, Concerning Briefing on IPE Insight Report," SECY-97-180, August 6,

1997.

2. U.S. Nuclear Regulatory Commission, "Performance-Based Containment Leak-Test

Program," NUREG-1493, September 1995.

3. U.S. Nuclear Regulatory Commission, "Review of Light Water Reactor Regulatory

Requirements," NUREG/CR-4330, PNL-5809, Vols. 1 and 2, April 1986 and June 1986.

4. U.S. Nuclear Regulatory Commission, Reactor Safety Study," WASH-1 400,

NUREG/75/014,1975.

5. U.S. Nuclear Regulatory Commission, "Technical Findings and Regulatory Analysis for

Generic Safety Issue I.E.4.3-Containment Integrity Check," NUREG-1273, April 1988.

6. U.S. Nuclear Regulatory Commission, "Severe Accident Risks: An Assessment for Five

U.S. Nuclear Power Plants, Final Summary Report," NUREG-1150, Vols. 1 and 2,

June 1989 and December 1990.

7. U.S. Nuclear Regulatory Commission, "Individual Plant Examination Program:

Perspectives on Reactor Safety and Plant Performance," NUREG-1560, Vol. 1,

December 1997.

8. Electric Power Research Institute, "Risk Impact Assessment of Revised Containment

Leak Rate Testing Intervals," EPRI TR-104285, August 1994.

9. U.S. Nuclear Regulatory Commission, "Performance Based Containment Leak Test

Program," Regulatory Guide 1.163, September 1995.

10. Nucleonics Week, "U.S. Nuclear Record Sustained as 2001 Output Nears 800-Million

MWH," February 14, 2002.

8
NRC FORM 335 U.S. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER

(2-89) (Assigned by NRC, Add Vol Supp., Rev, NRCM 1102 BIBLIOGRAPHIC DATA SHEET and Addendum Numbers. If any.)

3201.3= ILIG AHI02A HE

(See kisinrction on the reverse)

2. TITLE AND SUBTITLE NUREG-17m

Regulatory Effectiveness Assessment of Option B of Appendix J3. DATE REPORT PUBLISHED

MONTH YEAR

08 2003

4. FIN OR GRANT NUMBER

5. AUTHOR(S) 6. TYPE OF REPORT

John V. Kauffman

7. PERIOD COVERED (Inlusive Dates)

8. PERFORMING ORGANIZATION -NAME AND ADDRESS (f NRC provide Division. OfficeorRegion, U.S. NdearRegulatoryCommission, andmairngadass, ffc ractor.

provide name and mailing address.)

Division of Systems Analysis and Regulatory Effectiveness

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

Washington, D.C. 20555-0001

9. SPONSORING ORGANIZATION NAME AND ADDRESS (If NRC. type Sane aaove; N contractor, provide NRC Divslon. Office or Region, U.S NufearReguatoCrmisson.

and maling address.)

Same as above.

10. SUPPLEMENTARY NOTES

J.V. Kauffman, NRC Project Manager

11. ABSTRACT (200 words or ess)

The Nuclear Regulatory Commission's Office of Nuclear Regulatory Research is reviewing selected regulations to determine if

they are achieving the desired results. This nitiative is part of an evolving program to make NRC activities and decisions more

effective, efficient, and realistic. The goal of this assessment is to determine whether the revised, performance-based,

risk-informed, voluntary Option B of 10 CFR 50, Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled

Power Reactors was effective, and, if not, to make appropriate recommendations.

The effectiveness of Option B was determined by comparing regulatory expectations to outcomes. The assessment concluded

that risk-informing Appendix J has been effective. The revised Appendix J has been at least partially adopted by all currently

operating nuclear power plants. Its adoption has resulted in cost saving and burden reduction to licensees, while maintaining

safety. Note that this conclusion regarding maintenance of safety is based on probabilistic risk assessment insights and the

very limited failure data available since the adoption of Option B by licensees. Occupational radiation exposure to workers has

been reduced by adoption of the revised Appendix J. However, with the reduced frequency of Type A tests under Option B, it is

likely that a degraded containment will not beidentified as quickly as under he original Appendix J. Required licensee

inspections of containment structural members limit the potential for significant degradation to remain undetected for lengthy

periods of time.

1Z KEY WORDS/DESCRIPTORS (Lst words orplrases that ilassist researchers Inhoating the rort) 13. AVAILASIUTY STATEMENT

Appendix J unlimited

Option B 14. SECURITY CLASSIFICATION

Criterion 16 (This Page)

primary containment unclassified

integrated leak rate test (This Report)

local leak rate test unclassified

15. NUMBER OF PAGES

16. PRICE

NRC FORM 335 2-89)
L Printed

on recycled d

Fe a paper P

Federal Recycling Program
NUREG-1777 REGULATORY EFFECTIVENESS ASSESSMENT OF OPTION B OF APPENDIX J AUGUST 2003

UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, DC 20555-0001

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