ML16342D868
| ML16342D868 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/13/1997 |
| From: | Steven Bloom NRC (Affiliation Not Assigned) |
| To: | Rueger G PACIFIC GAS & ELECTRIC CO. |
| References | |
| GL-96-06, GL-96-6, TAC-M96805, NUDOCS 9711210236 | |
| Download: ML16342D868 (10) | |
Text
W gy 0
p 9
Cy
~O
+**++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November i3, 1997 Mr. Gregory M. Rueger, Senior Vice President and General Manager Pacific Gas and Electric Company Nuclear Power Generation N9B P.O.
Box 770000 San Francisco, California 94177
SUBJECT:
INFORMATION PERTAINING TO DIABLO CANYON NUCLEAR POWER PLANT UNIT 2 IMPLEMENTATION OF MODIFICATIONS ASSOCIATED WITH GENERIC LETTER 96-06.
"ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT INTEGRITY DURING DESIGN-BASIS ACCIDENT CONDITIONS" (TAC NO. M96805)
Dear Mr. Rueger:
The staff'ssued Generic Letter (GL) 96-06 on September 30.
1996.
The generic letter requested licensees to determine (1) if containment air cooler cooling water systems are susceptible to either waterhammer or two-phase flow conditions during postulated accident conditions, and (2) if piping systems that penetrate the containment are susceptible to thermal expansion of fluid so that overpressurization of piping could occur.
By letters dated January 28,
- 1997, as supplemented March 17,
- 1997, and July 28, 1997, you submitted your 120-day response to GL 96-06.
The staff is currently performing a detailed review of your response.
Implementing corrective actions to resolve the GL 96-06 issues can have a
significant impact on outage schedules and resources.
Some licensees have indicated that it would be prudent to take more time to better understand the specific concerns that have been identified in order to optimize whatever actions are needed and to assure that they do not ultimately result in a detriment to safety.
Current issues and ongoing efforts that could influence a licensee's decision in planning corrective actions include (1) risk implications of installing relief valves to deal with the thermal overpressurization
- issue, (2) feasibility of'sing the acceptance criteria contained in Appendix F to Section III of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for the permanent resolution of the GL 96-06 issues, (3) ongoing tests by the Electric Power Research Institute to support a generic resolution of the overpressurization of piping issue, and (4) questions regarding the staff's closure of Generic Safety Issue
- 150, "Overpressurization of Containment Penetrations."
Risk insights and industry initiatives that are being considered or that may be proposed could also influence the course of action that licensees take to resolve the GL 96-06 issues.
97ii2i023b 97iii3 PDR ADOCK 05000323 P
'DR
<v-.I Vgbg llllfllllllllllliIjiiiaiailIlgii,
Mr. Gregory M. Rueger November 13, 1997 Licensees are responsible for assessing equipment operability. determining
- actions, and establishing schedules that are appropriate for resolving the specific conditions that have been identified.
In determining the appropriate actions and schedules for resolving GL 96-06 issues, licensees should consider, for example, the continued validity of existing operability determinations, compensatory actions required to maintain operability, the safety significance associated with the specific nonconf'ormances or degraded conditions that have been identified, risk insights, and the time required to complete any generic initiatives and/or plant-specific actions (e.g..
engineering evaluations, design change
- packages, material procurement, and equipment modification and installation).
Also, analytical solutions employing the permanent use of the acceptance criteria contained in the ASME
- Code,Section III, Appendix F (or other acceptance criteria) may present viable alternatives to plant modifications and can be used where appropriate, justified, and evaluated in accordance with NRC requirements such as 10 CFR 50.59, as applicable.
Licensees may find the revised guidance contained in GL 91-18 'Information to Licensees Regarding Two NRC Inspection Manual Sections on Resolution of Degraded and Nonconforming Conditions and on Operability," Revision 1, dated October 8, 1997, helpful in determining appropriate actions and schedules.
Although adjustments in schedules may be warranted on the basis of these (and other ) considerations, specific actions that have been defined and are clearly needed should not be delayed without suitable justification.
It is the staft's current position that licensees can use the ASME Code.
Section III, Appendix F, criteria for interim operability determinations for degraded and nonconforming piping and pipe supports until permanent actions have been identified and approved by the NRC (as applicable) for resolving the GL 96-06 issues.
This guidance supplements the guidance provided by GL 91-18 for resolution of the GL 96-06 issues.
In order to further facilitate resolution of the GL 96-06 issues, the NRC will participate in a public workshop on this topic later this fall.
The workshop proceedings will be summarized by the NRC staff and made publicly available.
The need for additional NRC guidance and generic communication will be considered upon completion of the workshop.
If you choose to revise your commitments for resolving the GL 96-06 issues.
you should submit a revised response to the generic letter.
Your revised response should include appropriate discussion of the considerations
/~
re
Mr. Gregory M. Rueger
-'3-November13, 1997 discussed
- above, the current resolution status, and actions remaining to be completed.
and plans being considered for final resolution of the GL 96-06 issues.
If you have any questions.
please contact me at (301) 415-1313.
Sincerely, Original Signed By Docket No. 50-323 cc:
See next page Steven D. Bloom, Project Manager Project Directorate IV-2 Division of Reactor Projects
- III/IV Office of Nuclear 'Reactor Regulation DISTRIBUTION:
Docket PUBLIC PDIV-2 Reading EAdensam WBateman SBloom EPeyton OGC ACRS TMarsh BWetzel HWong, Region IV/WCFO
- KPerkins, Region IV/WCFO Document Name:
-2/PM DATE 11/i$ /97 PDIV-2/LA El@6%
11/iO/97
4
, g t
1L ll ff I
i
e Ck Mr. Gregory M. Rueger November 13, 1997 CC:
NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission
'P. 0.
Box 369 Avila Beach'alifornia 93424 Dr. Richard Ferguson, Energy Chair Sierra Club California 1100 11th Street, Suite 311 Sacramento, Cali fornia 95814 Ms. Nancy Culver San Luis Obispo Mothers for Peace P. 0.
Box 164 Pismo Beach, California 93448 Chairman San Luis Obispo County Board of Supervisors Room 370 County Government Center San Luis Obispo. California 93408 Mr;. Truman Burns Mr. Robert Kinosian California Public Utilities Commission 505 Van Ness
~
Room 4102 San Francisco.
Cali fornia 94102 Mr. Steve Hsu Radiologic Health Branch State Department of Health Services Post Office Box 942732 Sacramento, California 94232 Diablo Canyon Independent Safety Committee ATTN:
Robert R. Wellington, Esq.
Legal Counsel 857 Cass Street, Suite D
Monterey, California 93940 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower 8 Payillion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Christopher J. Warner, Esq.
Pacific Gas 8 Electric Company Post Office Box 7442 San Francisco, California 94120 Mr. Robert P.
Powers Vice President and Plant Manager Diablo Canyon Nuclear Power Plant P. '0.
Box 56 Avila Beach, California 93424 Telegram-Tribune ATTN:
Managing Editor 1321 Johnson Avenue P.O.
Box 112 San Luis Obispo, California 93406
a,
/
t
>/return Distri97.txt Distribution Sheet Priority: Normal From: Linda Eusebio Action Recipients:
S Bloom E Peyton Internal Recipients:
RES/DET/MEB RES/DET/ERAB OGC-FXLE CENTER 01 ACRS Copies:
1 1
Not Found Not Found Not Found Not Found Not Found Not Found Not Found External Recipients:
NOAC INEEL Marshall Not Found Not Found Total Copies:
Item:
ADAMS Package Library:
ML ADAMS"HQNTAD01 ID: 003678011
Subject:
OR Submittal: Inservice/Testing/Relief from ASME Code Body:
Docket:
- 05000323, Notes:
N/A Page 1
l 1
1 E