ML20151R036
| ML20151R036 | |
| Person / Time | |
|---|---|
| Issue date: | 08/01/1988 |
| From: | Wohl M Office of Nuclear Reactor Regulation |
| To: | Butcher E Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8808120032 | |
| Download: ML20151R036 (4) | |
Text
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UNITED CTATES 5
NUCLEAR REGULATORY COMMISSION n
j WASHINGTON, D. C. 20665
- Q*****l AUG I 1988 MEMORANDUM FOR:
Edward J. Butcher, Chief Technical Specifications Branch Division of Operational Events Assessment, NRR THRU:
Richard L. Emch, Jr., Section Leader Special Projects Section Technical Specifications Branch Division of Operational Events Assessment, NRR FROM:
Millard L. Wohl Special Projects Section Technical Specifications Branch Division of Operational Events Assessment, NRR
SUBJECT:
SUMMARY
OF MEETING WITH WESTINGHOUSE ON TOPICAL REPORT WCAP-10271, SUPPLEMENT 2, REVISION 1, "EVALUATION OF SURVEILLANCE FREQUENCIES AND OUT OF SERVICE TIMES FOR THE ENGINEERED SAFETY FEATURES ACTUATION SYSTEM" 0TSB, SICB, and PRAB staff members met with personnel from Westinghouse Electric Corporation to discuss problems encountered in the review of Topical Report WCAP-10271, Supplement 2, Revision 1, A Vendor /0wners Group presentation was made on extensions of surveillance intervals (STIs) and allowed outage times (A0Ts) for the ESFAS.
Two important problem areas discussed in the meeting were (1) Channel Logic Considerations, and (2) "Case 1" vs. "Case 3" analyses.
These are discussed below.
o Channel Logic Considerations Westinghouse asserted that 2/3 and 2/4 channel logics are not significantly different from a risk perspective with respect to extended STIs and A0Ts.
Brookhaven National Laboratory (BNL), the staff's contract reviewer, agrees with the WCAP-10271, Supplement 2, Revision 1 analyses for solid state and relay plants operating with 2/4 channel logic.
A 2/3 channel logic analysis was not done, however, with application to a specific plant; the Millstone-3 reference plant is a 2/4 plant. Many Westinghouse plants have systems with 2/3 channel logic, o
"Case 1" vs. "Case 3" Analyses l
A substantial number of analyses were performed for "Case 1" (WCAP-10271, Supplement 2, Revision 1) STI and A0T parameters to compare ESFAS unavail-abilities obtained with those of the "Base Case".
However, Westinghouse.
requested that "Case 3" STI and A0T parameters be granted (extended STI, f'F A0T values).
Instead of redoing the extensive calculations for "Case 3",
(
Westinghouse used the "Case 1" calculations and relied on the similarity 0# gy) 8808120032 880801 g
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AUD 1 688 Page 2 of the "Case 1" and "Case 3" parameters.
Westinghouse estimated a 2.4%
core damage frequency (C0F) increase and a 1.7% person-Rem increase for "Case 3" compared with the "Base Case."
The issues discussed above, Channel Logic Considerations (2/3 vs. 2/4) and "Case 1" vs. "Case 3" analyses will be resolved through some additional analysis.
Westinghouse has agreed to perform additional calculations comparing "Case 3" ESFAS unavailabilities with those of the "Base Case".
OTS will discuss the results of these analyses with Westinghouse during 3
the week of August 1.
Comparative core damage frequency estimates (BNL vs. Westinghouse Owners Group) related to STI and A0T modification requests were discussed with Westinghouse staff.
They are as follows:
o Core Damage Frequency Estimates The BNL review calculations yielded a CDF frequency increase of 2.8%
for solid state plants if the STI and A0T modifications ("Case 3")
requested by the Westinghouse Owners Group (WOG) are granted.
This is in close agreement with the 2.4% Westinghouse C0F increase estimate.
The corresponding increase of C0F for relay plants calculated by BNL, assuming concurrent slave relay testing, is 4%.
Finally, the staff raised a concern related to computed ESFAS unavailabilities due to the Auxiliary Feedwater Pump Start Signal failure.
Several computed ESFAS unavailabilities are above the staff's goal of 1 x 10 4 even for the "Base Case" and increase by as much as a factor of 4 for "Case 1" (steam generator level lo lo conditions).
This concern is presently under review by SICB. is an attendance list. is the meeting announcement.
06cinal Signed By Millard L. Wohl Special Projects Section Technical Specifications Branch Division of Operational Events Assessment, NRR
Enclosures:
As stated cc:
w/ enclosures TEMurley JHSniezek TTMartin CERossi DISTRIBUTION:
OTSB R/F OSTB Members JJoyce RLEmch KCampe POR WDLanning 00EA R/F CHBerlinger Echow EJButcher SNewberry Central Files f.Barrett 0FC: TSB:00EA:NRR:TSB:00EA:NRR:
N E L h R
c DATE: 1/O'/88
- 3/01/88 0FFICIAL RECORD COPY
pp
} 1%S Page 2 of the "Case 1" and "Case 3" parameters.
Westinghouse estimated a 2.4%
core damage frequency (CDF) increase and a 1.7% person-Rem increase for "Case 3" compared with the "Base Case."
The issues discussed above, Channel Logic Considerations (2/3 vs. 2/4) and "Cece 1" vs. "Case 3" analyses will be resolved through some additional analysis.
Westinghouse has agreed to perform additional calculations comparing "Case 3" ESFAS unavailabilities with those of the "Base Case".
OTSB will discuss the results of these analyses with Westinghouse during the week of August 1.
Comparative core damage frequency estimates (BNL vs. Westinghouse Owners Group) related to STI and A0T modification requests were discussed with Westinghouse staff.
They are as follows:
o Core Damage Frequency Estimates The BNL review calculations yielded a CDF frequency increase of 2."
for solid state plants if the STI and A0T modifications ("Case 3'.
requested by the Westinghouse Owners Group (WOG) are granted.
This is in close agreement with the 2.4% Westinghouse CDF increase estimate.
The corresponding increase of CDF for relay plants calculated by BNL, assuming concurrent slave relay testing, is 4%.
Finally, the staff raised a concern related to computed ESFAS unavailabilities due to the Auxiliary Feedwater Pump Start Signal failure.
Several computed ESFAS unavailabilities are above the staff's goal of 1 x 10 4 even for the "Base Case" and increase by as much as a factor of 4 for "Case 1" (steam generator level lo lo conditions).
This concern is presently under review by SICB. is an attendance list. is the meeting announcement.
Oririnal Si:ned By Millard L. Wohl Special Projects Section Technical Specifications Branch Division of Operational Events Assessment, NRR
Enclosures:
As stated cc:
w/ enclosures TEMurley JHSniezek TTMartin CERossi DISTRIBUTION:
0TSB R/F OSTB Members JJoyce RLEmch KCampe PDR UDLanning 00EA R/F CHBerlinger EChow EJButcher SNewberry hentralFiles RBarrett 0FC: TSB: 00EA: NRR: TSB: 00EA: NRR:
NAME:MLWohi 8/-
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- RLEmch'/(' :
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DATE:f/O'/88
- f/01/88 OFFICIAL RECORD COPY
I NAME AFFILIATION PHONE NO.
R. C. Howard Westinghouse (412) 374-4159 Lee Bush Commonwealth Edison (815) 458-2801 ext. 2511 G. R. Andre Westinghouse (412) 374-4095 Gregg A. Sinders Carolina Power & Light Co. (919) 362-3260 Rich Emch NRC (301) 492-1186 Scott Newberry NRC (301) 492-0782 Ed Chow NRC (301) 492-1077 Millard Wohl NRC (301) 492-1181 6
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Page 4 ENCLOSURE 2 HEMORANDUM FOR:
Edward J. Butcher, Chief aical Specifications Branch is Division of Operational Events Assessment, NRR FROM:
Richard L. Emch, Jr., Section Chief Special Pro.jects Section Technical Specifications Branch
SUBJECT:
FORTHCOMING MEETING FOR CULMINATING REVIEW 0F WESTINGHOUSE TOPIf.L REPORTS WCAP-10271, SUPPLEMENT 2, REVISION 1, "EVALUATION OF.C:RVEILLANCE FREQUENCIES AND OUT-0F-SERVICE TIMES FOR THE L JIHEERED SAFETY FEATURES ACTUATION SYSTEM."
DATE & TIME:
Thursday, July 14 1988, 9:30-12:30 LOCATION:
Nuclear Regulatory Commission White Flint -Srth Building Room 14811 11555 Rockville~ Pike Rockville, Maryland 20852 PURPOSE:
TO DISCUSS PRA MODELLING, ESFAS OPERATION AND TESTING, AND ESFAS TECHNICAL SPECIFICATIONS PARTICIPANTS:
NRC WESTINGH0llSE WOG S. Newberry R. Howard G. Sinders J. Mauck G. R. Andre R. Emch M. Reinhart COMMONWEALTH EDIS0N M. Wohl Lee Bush D. Lasher E. Chow Richard L. Emch, Jr., Section Chief Technical' Specifications Branch Divisions of Operational Events Assessment, NRR OFC:TSB:00EA:NRR:
NAME:MLWohl
- RLEmch :
DATE:6/23/88
- 6/23/88:
0FFICIAL RECORD COPY
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