ML20149L170
| ML20149L170 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 07/29/1997 |
| From: | Quay T NRC (Affiliation Not Assigned) |
| To: | Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| NUDOCS 9707310169 | |
| Download: ML20149L170 (3) | |
Text
I pm%
)
p-4 UNITED STATES g
j NUCLEAR REGULATORY COMMISSION c
2 WASHINGTON, D.C. 20565 40H
.....,o July 29, 1997 hf&&
Mr. Nicholas J. Liparulo, Manager Nuclear Safety and Regulatory Analysis Nuclear and Advanced Technology Division Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230
)
SUBJECT:
AP600 INSERVICE TESTING RELIEF REQUEST FOR AUTOMATIC DEPRESSURIZATION SYSTEM (ADS) VALVE TEST FREQUENCY
Dear Mr. Liparulo:
Westinghouse letter NSD-NRC-97-5155, dated June 6, 1997, supplements Westing-house letter NSD-NRC-97-4986, dated February 14, and responds to the Nuclear Regulatory Commission (NRC) letters dated April 22, 1997, and May 29, 1997, regarding a request for relief froin ASME Boiler and Pressure Vessel Code Section XI requirements. Specifically, Westinghouse proposes to increase the i
inservice testing frequency of the AP600 ADS stage 1, 2 and 3 valves from 1
three to six months.
In the June 6, 1997, letter, Westinghouse reiterates its previous bases for relaxing the ADS inservice testing interval, i.e., the i
AP600 probabilistic risk assessment (PRA) results demonstrate that AP600 meets the NRC safety goals with a six-month test frequency of the ADS valves, and that meeting these safety goals establishes an acceptable level of quality and safety. The NRC staff stated in its May 29, 1997, letter that additional quantitative information needs to be provided to determine if the increase in risk (due to reduced valve reliability from an increased test interval) can be compensated by the decrease in risk from reduction of a potential human error induced loss-of-coolant-accident as a result of less frequent testing.
Westinghouse did not provide additional information supporting the relief request in accordance with the guidance provided in NRC letter dated May 29,
'1997. Without this additional information, the staff cannot continue its review and, therefore, cannot justify the relaxation of the quarterly testing requirements.
A conference call was held between Westinghouse and the NRC staff on July 10, 1997. The purpose of the call was to discuss Westinghouse's proposal to use a PRA approach to justify extending the ADS valve test frequency from 3 months to 6 months. Westinghouse stated that the AP600 PRA results (which assumed an ADS. valve test frequency of 6 months) met the NRC safety goals and, therefore, should provide an acceptable level of quality and safety. The staff told Westinghouse that meeting the NRC safety goal was not an appropriate accep-tance criterion for a risk-informed (RI) approach.
During the conference call, Westinghouse was asked if its PRA results met the acceptance criteria delineated in the draft Regulatory Guide (RG) and Standard Review Plan (SRP)
{
for RI inservice testing (IST). Westinghouse was not aware of these docu-ments.
g y
L 9707310169 970729 PDR ADOCK 05200003 A
t Mr. Nicholas J. Liparulo July 29, 1997 j
i Westinghouse should either comply with the ASME Code Section'XI 3 month test l
frequency for the ADS stage 1, 2 and 3 valves or provide the requested relief justification in accordance with the guidance in NRC-letter dated May 29, 1997, or use the RI-IST approach outlined in the draft RG _and SRP. However, should Westinghouse elect to choose a RI-IST approach for its ADS relief request, the NRC staff would need to coordinate the review with in-progress RI-IST reviews at selected pilot operating reactors to ensure consistency in implemeatation-of NRC's PRA policy statement. Using an RI-IST approach to the 4
1 ADS valve relief request could result in an impact on the AP600 review l
schedule.
It should be noted that relief requests, if justified, may be submitted by future COL holders at any time during the life of plant opera-tion.
j If you have any questions regarding this matter, you can contact Bill Huffman j
at (301) 415-1141.
Sincerely, j
OriginalSignedBF Theodore R. Quay, Director.
{
Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation j
Docket No.52-003 j
cc: See next page DISTRIBUTION:
1 Docket File PDST R/F MSlosson 1
PUBLIC SWeiss TRQuay TKenyon BHuffman JSebrosky DJackson WDean, 0-5 E23 ACRS (11)
JMoore, 0-15 B18 GBagchi, 0-7 HIS JHuang, 0-7 HIS Glainas, 0-7 D24 BSheron, 0-7 D24 DTerao, 0-7 E23 J
DOCU n
MENT NAME: A: ADS-IST.RV2 r - copy wie d M nti.ncio.or.
. m. m
. me m m. w c. cm,anoui.ei. ohm.ni/.ne.u,.
m. w copy 0FFICE PM:PDST:DRPM ECGB:DF,/St g SC:EMEB:#4 G
BCMC$MDE l
D:PDST:DRPM NAME WCHuffman:k h JHuang i DTerao F\\
- Bagdii TRQuay T1%
DATE 7/d/97
\\
5 q />f/97
~7/2 /97
- -1/ g/97 7 /4 /97 0FFICIAL RECORD COPY
,o Mr. Nicholas J. Liparulo Docket No.52-003 i
Westinghouse Electric Corporation AP600 cc: Mr. B. A. McIntyre Mr. Ronald Simard, Director Advanced Plant Safety & Licensing Advanced Reactor Programs Westinghouse Electric Corporation Nuclear Energy Institute Energy Systems Business Unit 1776 Eye Street, N.W.
P.O. Box 355 Suite 300 Pittsburgh, PA 15230 Washington, DC 20006-3706 Mr. Cindy L. Haag Ms. Lynn Connor Advanced Plant Safety & Licensing Doc-Search Associates Westinghouse Electric Corporation Post Office Box 34 Energy Systems Business Unit Cabin John, MD 20818 Box 355 Pittsburgh, PA 15230 Dr. Craig D. Sawyer, Manager Advanced Reactor Programs Mr. S. M. Modro GE Nuclear Energy Nuclear Systems Analysis Technologies 175 Curtner Avenue, MC-754 Lockheed Idaho Technologies Company San Jose, CA 95125 Post Office Box 1625 Idaho Falls, ID 83415 Mr. Robert H. Buchholz GE Nuclear Energy Mr. Sterling Franks 175 Curtner Avenue, MC-781 U.S. Department of Energy San Jose, CA 95125 NE-50 19901 Germantown Road Barton Z. Cowan, Esq.
Germantown, MD 20874 Eckert Seamans Cherin & Mellott 600 Grant Street 42nd Floor Mr. Frank A. Ross Pittsburgh, PA 15219 U.S. Department of Energy, NE-42 Office of LWR Safety and Technology Mr. Ed Rodwell, Manager 19901 Germantown Road PWR Design Certification Germantown, MD 20874 Electric Power Research Institute 3412 Hillview Avenue Mr. Charles Thompson, Nuclear Engineer Palo Alto, CA 94303 AP600 Certification NE-50 19901 Germantown Road Germantown, MD 20874