ML20206S744

Informs That During 460th Meeting on 990310-13,ACRS Discussed Several Matters & Completed Listed Repts & Ltrs. Committee Also Authorized Larkins,To Transmit Noted Memo

ML20206S744
Person / Time
Site:	05200003
Issue date:	04/16/1999
From:	Powers D Advisory Committee on Reactor Safeguards
To:	Shirley Ann Jackson, The Chairman NRC COMMISSION (OCM)
References
ACRS-SL-0469, ACRS-SL-469, SECY-99-054-C, SECY-99-54-C, NUDOCS 9905210208
Download: ML20206S744 (9)

Text

y '

, SL-0469 1 1 purg% UNITED ST4TES E NUCLEAR REGULATORY COMMISSION PDR

. $ ADVISORY COMMITTEE oN REACTOR SAFEGUARDS e o WASHINGTON, D. C. 20586 April 16,1999 The Honorable Shirley Ann Jackson Chairman U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001

SUMMARY

REPORT- FOUR HUNDRED SIXTIETH MEETING OF THE ADVISORY COMMITTEE ON REACTOR SAFEGUARDS, MARCH 10-13, 1999, AND OTHER RELATED ACTIVITIES OF THE COMMITTEE During its 460th meeting, March 10-13, 1999, the Advisory Committee on Reactor Safeguards (ACRS) discussed several matters and completed the following reports and letters. In addition, the Committee authorized Dr. Larkins, Executive Director, to transmit the memoranda noted below:

REPORTS l SECY-99-054. Plans for Final Rule - Revisions to 10 CFR Parts 50. 52. and 72:

Reauirements Concernino Chanaes. Tests. and Experiments"(Report to Shirley Ann Jackson, Chairman, NRC, from Dana A. Powers, Chairman, ACRS, dated

. March 22,1999)

Core Research Capabilities (Report to Shirley Ann Jackson, Chairman, NRC, from Dana A. Powers, Chairman, ACRS, dated March 22,1999)

LETTERS

• 1 Lessons Learned from the ACRS Review of the AP600 Desian (Letter to William D.

Travers, Executive Director for Operations, NRC, from Dana A. Powers, Chairman, ACRS, dated March 22,1999)

• Proposed Amendment to 10 CFR 50.72. Immediate Notification and 50.73.  !

Licensee Event Reportina System (Letter to William D. Travers, Executive Director for Operations, NRC, from Dana A. Powers, Chairman, ACRS, dated March 23, 1999) ,

$:30 D

\

9905210209 990416 3 N W w. C G E ti c y gl PDR ACRS -

L/

SL-0469 PDR 2 g Q '.

C t'fiud Dy _ .

i. The Honorable Shirley Jackson 2

- Apolication of Westinahouse Best-Estimate Loss-of-Coolant Accident Analysis Methodoloav to Upoer Plenum Injection Plants (Letter to William D. Travers, Executive Director for Operations, NRC, from Dana A. Powers, Chairman, ACRS, dated March 24,1999)

Hiah Burnuo Fuel Phenomena identification and Rankina (Letter to William D.

Travers, Executive Director for Operations, NRC, from Dana A. Powers, Chairman, ACRS, dated March 24,1999)

Guidance Memorandum for imolementation of the Revised Enforcement Poliev (Letter to William D. Travers, Executive Director for Operations, NRC, from Dana A. Powers, Chairman, ACRS, dated March 24,1999)

- Proposed ASME Standard for Probabilistic Risk Assessment for Nuclear Power Plant Acolications (Phase 1)(Letter to William D. Travers, Executive Director for Operations, NRC, from Dana A. Powers, Chairman, ACRS, dated March 25,1999)

MEMORANDA

- Dearaded Switchyard Voltaae issues at Palo Verde Nuclear Generatina Station Unit 41. 2. and 3 (Memorandum to William D. 'l ravers, Executive Director for Opera-tions, NRC, from John T. Larkins, Executive Director, ACRS, dated March 22,1999)

Safetv Evaluation Reaardina Combustible Gas Controlin Containment at Indian Point 2 (Memorandum to William D. Travers, Executive Director for Operations, NRC, from John T. Larkins, Executive Director, ACRS, dated March 23,1999)

HIGHLIGHTS OF KEY ISSUES CONSIDERED BY THE COMMITTEE i

1. SECY-99-054. " Plans for Final Rule and Revisions to 10 CFR Parts 50. 52. and 72- '

Reauirements Concernina Chanaes. Tests. and Exogriments" l l I

The Committee heard presentations by and held discussions with representatives I of the NRC staff regarding SECY-99-054. The Committee discussed the staff's i proposed resolution of public comments and recommendations for revising 10 CFR l 50.59. The Committee and staff discussed issues related to use of the term l

" minimal" rather than " negligible" for increases in probability or consequences, the l l industry's approach to maintaining the design bases of fission product barriers, the I

scope of 10 CFR 50.59, and margin of safety. The Committee also considered the Commission's request included in the Staff Requirements Memorandum dated March 5,1999, that the ACRS provide key questions and issues that should be considered during the current 10 CFR 50.59 rulemaking effort as well as any I

f

l The Honorable Shirley Jackson 3 recommended answers or positions. The Committee previously provided a list of questions in its February 18,1999, report to the Commission.

Conclusion <

The Committee issued a report to Chairman Jackson, dated March 22,1999, on this ,

matter. The Committee plans to review the proposed final rule during its May 5-8, 1999 meeting.

2. Westinahouse Best-Estimate Larae-Break LOCA Methodoloav The Committee heard presentations by and held discussions with representatives of the Westinghouse Electric Company and the NRC staff regarding the application l of the Westinghouse best-estimate large-break LOCA methodology, which utilizes i the WCOBRA/ TRAC code, to Upper Plenum injection (UPI) plants. This j methodology had previously been approved for use in 3- and 4-loop Westinghouse i plants. The Committee discussed key issues associated with the application of I WCOBRA/ TRAC code to the UPI plants, including the adequacy of the use of the  !

steps described in the Code Scaling, Applicability, and Uncertainty evaluation methodology, as well as whether modeling of the phenomena of interfacial i condensation and drag have been appropriately ranged in the code. The NRC staff stated that it has found the WCOBRAITRAC code acceptable for modeling of large-break LOCA for UPI plants.

Conclusion

)

The Committee issued a letter to the Executive Director for Operations, dated March 24,1999, on this matter.

3. Proposed Phase 1 Standard for PRA Quality The Committee met with representatives of the American Society of Mechanical Engineers (ASME) Committee on Nuclear Risk Management (CN RM) to discuss the proposed Phase 1 Standard for Probabilistic Risk Assessment (PRA) for Nuclear Power Plant Applications. Representatives of the NRC staff, who participated on the CNRM working committees, were also involved in the Committee's discussions on this matter. Representatives of the Nuclear Energy Institute (NEI) provided a brief report on the status of industry initiatives to certify PRAs and discussed possible integration of these initiatives with the ASME Standard.

The Committee discussed possible use of the Standard as a means to ensure that the technical quality of PRAs is sufficient to support the regulatory review and

E 9,

y The Honorable Shirley Jackson 4 approval of licensee applications. The Committee offered comments and suggestions on the use of analytical models and methods, balance between specificity and flexibility of requirements, the peer-review process, and treatment of expert judgment.

Conclusion The Committee issued a letter to the NRC Executive Director for Operations, dated March 25,1999, on this matter.

4. Proposed Rule for Event Reportino Reauirements The Committee heard presentations by and held discussions with representatives of the NRC staff and NEl concerning proposed revisions to 10 CFR 50.72, "Immediate Notification Requirements for Operating Power Reactors," and 50.73,

" Licensee Event Reporting System." Items discussed included the rationale for the required length of time within which licensees must report events, how the staff verifies that licensees provide required reports, and the possibilities for developing site-specific lists of reportable engineered safety feature actuations.

Conclusion The Committee issued a letter to the NRC Executive Director for Operations, dated March 23,1999, on this matter.

5. Reevaluation of the Generic Safety issue Process The Committee heard presentations by and held discussions with representatives of the NRC staff regarding the results of the reevaluation of the Generic Safety issue (GSI) Process. The staff summarized the principal observations made during the reevaluation process. The staff stated that there are many misconceptions of the GSI process, the most significant one is that safety is adversely affected while a GSI remains unresolved.

On the basis of the reevaluation, the staff recommends that the GSI process be implemented using two levels of guidance; the first at the agency-wide level which I would take the form of a Management Directive or Commission policy statement, l and the second would entail more detailed office level procedures which consider I

explicitly the distinctive aspects of work in the office. The staff presented a preliminary version of the Management Directive 6.4," Generic issue Process," and an associated Handbook. The staff plans to issue the Management Directive and the Handbook for public comment in May 1999.

r l

The Honorable Shirley Jackson 5 l

Conclusion The Committee deferred its comments to the April 1999 ACRS meeting. The .

l Cornmittee plans to review another version of the Management Directive 6.4 and of an associated Handbook at a future ACRS meeting.

6. Licensino Framework for Fuel Burnuo Extension /NRC Particioation in the CABRI

' Reactor Fuels Research Proaram i The Committee heard presentations by and held discunsions with representatives of the NRC staff and the industry regarding the status of the NRC confirmatory research program on high-burnup fuel. The Committee and staff discussed the status of activities associated with extending fuel burnup beyond the current regulatory limit of 62 Gwd/t. The proposed use of phenomena identification and ,

ranking. This method could be used to rank the relative importance of phenomena '

that affect high-bumup fuel and to provide a technical basis for establishing the data and analyses needed to support applications for extending fuel burr !p beyond the j current regulatory limit. Key issues discussed at the meeting include current licensing requirements, impact of extended fuel burnup on the chemical forms and volatilities of radionuclides and on the accident source term.

Conclusion The Committee issued a letter to the NRC Executive Director for Operations, dated March 24,1999, on this matter.

7. Guidance for imolementino the Revised Enforcement Poliev The Committee heard presentations by and held discussions with representatives j of the NRC staff and NEl concerning the guidance memorandum for implementing the revised Enforcement Policy and a proposed approach for making the Enforcement Policy risk informed. items discussed include notices of violation for repeated violations, use of inspection findings and violations in the assessment process, and development of risk metrics for use in implementing the Enforcement Policy.

Conclusion The Committee issued a letter to the NRC Executive Director for Operations, dated March 24,1999, on this matter.

The Honorable Shirley Jackson 6

8. Safety Evaluation Report on the Tooical Reoort Recardina Tritium Production Core I

The Committee heard presentation by and held discussions with representatives of the Department of Energy (DOE), its contractors, and the NRC staff regarding the issues related to tritium production in commercial nuclear power plants.

DOE is responsible for establishing the capability to produce tritium by the end of the year 2005, in accordance with a Presidential decision directive. DOE has selected the commercial light water reactor (CLWR) as the primary means to produce tritium, with the accelerator production of tritium as a backup. DOE has developed burnable poison rods using lithium aluminate, rather than boron, in pressurized water reactor fuel assemblies. As a result of irradiation by neutrons in the reactor core, some of the lithium in the target rods is converted to tritium. The

)

irradiated burnable poison rods can then be removed from the fuel assemblies and shipped to another location (e.g., Savannah River Plant ) for tritium extraction.

The NRC staff prepared a draft safety evaluation report (DSER) regarding a DOE topical report on the tritium production. In its DSER, the staff concluded that many of the technicalissues related to the use of tritium production burnable absorber rods in CLWRs have been satisfactorily addressed by DOE. The staff, however,  ;

identified several plant-specific interface issues for which a licensee will have to provide additionalinformation and analysis in support of a gant-specific amendment for authorization to operate a tritium production core.

Conclusion The Committee plans to continue its review of this matter at future meetings. Also, it plans to review a plant-specific application for license amendment.

9. NRC Safety Research Proaram The Committee continued its discussion of the 1999 report to the Commission regarding the NRC Safety Research Program. Several research areas were Gscussed, including human factors and human-machine interface; high burnup fuel performance; thermal-hydraulic code integration and in-house capabilities; advanced instrumentation and controls; integrity of steam generators; integrity of reactor pressure vessels; irradiation-assisted stress corrosion cracking; and severe accident research.

p i

l3 The Honorable Shirley Jackson 7 i

! Conclusion l

l The Committee plans to continue its discussion of this matter during the May 1999 ACRS meeting.

RECONCILIATION OF ACRS COMMENTS AND RECOMMENDATIONS

- The Committee discussed briefly the response from the NRC Executive Director for Operations (EDO) dated March 8,1999, to ACRS comments and recommendations l included in NUREG-1835 Vol.1, Review and Evaluation of the NRC Safety i Research Program.

The Committee decided to continue its discussion of the EDO response during the April 7-10,1999 ACRS meeting.

OTHER RELATED ACTIVITIES OF THE COMMITTEE During the period from February 3,1999 through March 10,1999, the following Subcom-mittee meetings were held:

. Thermal-Hydraulic Phenomena - February 23,1999 The Subcommittee continued its review of the application of Westinghouse Electric Company's WCOBRA/ TRAC best-estimate large-break LOCA code to Westinghouse plants with Upper Plenum Injection.

. Plannina and Procedures - March 9,1999 The Planning and Procedures Subcommittee discussed proposed ACRS activities, I practices, and procedures for conducting Committee business and organizational and personnel matters relating to ACRS and its staff.

l

. LIST OF FOLLOW-UP MATTERS FOR THE EXECUTIVE DIRECTOR FOR OPERATIONS

- The Committee plans to review the proposed final revision to 10 CFR 50.59 during the May 1999 ACRS meeting.

- The Committee plans to review the proposed final amendment to 10 CFR 50.72, "Immediate Notification Requirements for Operating Powers Reactors," and 50.73,

" Licensee Event Reporting System," after reconciliation of public comments.

1

[

l 1

. The Honorable Shirley Jackson 8

<o

- The Committee plans to review the proposed final Phase 1 ASME Standard for PRA quality following the reconciliation of public comments.

- The Committee plans to continue its review of activities associated with tritium production at commercial light water reactors; also, it plans to review the associated plant-specific applications for license amendment.

- The Committee plans to review another version of the Management Directive 6.4,

" Generic lasue Process," and of an associated Handbook during a future ACRS meeting.

PROPOSED SCHEDULE FOR THE 461ST ACRS MEETING I

The Committee agreed to consider the following during the 461st ACRS Meeting, April 7-10,1999:

1 Draft Commissior Paper on Proposed imorovements to the Generic Communications Process The Committee will hear presentations by and hold discussions with representatives of the NRC staff regarding the draft Commission Paper on proposed improvements to the Generic Communications Process.

Steam Generator Tube and Reactor Pressure Vessel Intearity issues The Committee will hear presentations by and hold discussions with representatives of the NRC staff regarding the status of ongoing regulatory activities associated with steam generator tube integrity; staff's draft safety evaluation of Boiling Water Reactor Vessel and Internals Project-14 (BWRVIP-14), " Evaluation of Crack Growth in BWR Stainless Steel Reactor Pressure Vessel Infernals;" suggested changes to 10 CFR 50.61, pressurized thermal shock rule; and related matters.

l Insichts Gained from the Risk-informed Pilot Aoolicatiqn.g n i The Committee will hear presentations by and hold discussions with representatives of the NRC staff and the Nuclear Energy Institute (NEI) regarding the Insights gained from the l risk-informed pilot applications, including those from the pilots for inservice inspection, extension of allowed outage times, and online maintenance.

Proposed Final Revision to 10 CFR 50.65(a) of the Maintenance Rule and an Associated

' Draft Reaulatorv Guide The Committee will hear presentations by and hold discussions with representatives of the NRC staff and NEl regarding the proposed final revision to 10 CFR 50.65(a) of the Maintenance Rule that would require licensees to perform safety assessments prior to performing maintenance activities, and an associated draft Regulatory Guide.

l 1

P g The Honorable Shirley Jackson 9 Proposed Aporoach for Revisino the Commission's Safety Goal Policy Statement The Committee will hear presentations by and hold discussions with representatives of the NRC staff regarding the proposed approach for revising the Commission's Safety Goal Policy Statement.

Imoact of the Use of Hiah Burnuo or Mixed Oxide Fuel on the Revised Source Term The Committee will dis runs proposed ACRS response to a Commission request, included in the March 5,1999 Stutf Requirements Memorandum (SRM), that the ACRS considerthe impact of the use of high burnup or mixed oxide fuel on the revised source term.

Relationshio and Balance Between PRA Results and Defense-in-Deoth The Committee will discuss proposed ACRS response to a Commission request, included in the March 5,1999 SRM, that the ACRS consider the appropriate relationship and balance between PRA results and defense-in-depth in the context of risk-informed regulation.

Sincerely, l mG w=_ __1 J Dana A. Powers Chairman i

i 1

I I

l l

t