ML13302B404
| ML13302B404 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/07/1991 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML13302B405 | List: |
| References | |
| GL-88-17, TAC-69745, TAC-69774, NUDOCS 9105100261 | |
| Download: ML13302B404 (6) | |
Text
ACCELERATED DITRIBUTION DEMONST TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9105100261 DOC.DATE: 91/05/07 NOTARIZED: NO DOCKET #
FACIL:50-361 San Onofre Nuclear Station, Unit 2, Southern Californ 05000361 50-362 San Onofre Nuclear Station, Unit 3, Southern Californ 050 AUTH.NAME AUTHOR AFFILIATION ROSENBLUM,R.M.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION R
Document Control Branch (Document Control Desk)
I
SUBJECT:
Forwards CE NPSD-550, "Risk Evalution of Removal of Shutdown Cooling Sys Autoclosure Interlock," to support Amend D
Applications 101 & 86 to Licenses NPF-10 & NPF-15, respectively re Generic Ltr 88-17 on loss of DHR.
S DISTRIBUTION CODE: AO61D COPIES RECEIVED:LTR ENCL SIZE: !_74 TITLE: OR/Licensing Submittal: Loss of Residual Heat Removal (RHR) GL-87-12 NOTES:
A RECIPIENT COPIES RECIPIENT COPIES D
ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1
0 PD5 PD 1
1 D
KOKAJKO,L.
1 1
S INTERNAL: ACRS 6
6 NRR BALUKJIAN,H 2
2 NRR TRAMMELL,C 1
1 NRR/DOEA/OTSB11
.1 1
NRR/DST 8E2 1
1 OC/
1 0
OGC/HDS3 1
0
,R FI LE 01 1
1 RES/DSIR/EIB 1
1 EXTERNAL: NRC PDR 1
1 NSIC 1
1 R
I D
S A
D D
NOTE TO ALL "RIDS" RECIPIENTS:
S PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P1-37 (EXT. 20079) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 20 ENCL 17
Southern California Ed'ison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 R. M. ROSENBLUM TELEPHONE MANAGER OF M
(714) 454-4505 NUCLEAR REGULATORY AFFAIRS U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket Nos. 50-361 and 50-362 Amendment Application Nos. 101 and 86 Change to Technical Specification 3/4.5.2 ECCS Subsystems -
Tav, Greater Than or Equal to 350 0F.
Emergency Core Cooling Systems (TAC Nos. 69774 and 69745)
San Onofre Nuclear Generating Station Units 2 and 3
References:
- 1) Generic Letter 88-17, "Loss of Decay Heat Removal"
- 2) Letter from Harold B. Ray (SCE) to NRC dated April 15, 1991,
Subject:
Amendment Application Nos. 101 and 86 Change to Technical Specification 3/4.5.2 ECCS Subsystems -
Ta, Greater Than or Equal to 3500F, Emergency Core Cooling Systems (TAC Nos. 69774 and 69745)
- 3) Letter from P. R. Nelson (ABB) to Operations Subcommittee, Analysis Subcommittee, (Task 582 Participants) dated April 30, 1991,
Subject:
"Clarification of Operator Error Probability used in CE NPSD-550" In accordance with our commitment in reference 2, enclosed is the Combustion Engineering Owners' Group (CEOG) report "Risk Evaluation of Removal of the Shutdown Cooling System Auto Closure Interlock" and an associated clarification report (reference 3).
910y5:OO26 1 910507 DbR ADOCK 05000:'361 P'
Document Control Desk
- 2 This report and clarification support the recommendations of reference 1, Generic Letter 88-17, and of the CEOG to remove the Shutdown Cooling System Auto-Closure Interlock. This report was referenced in support of our license amendment application Nos.
101 and 86 for San Onofre Units 2 and 3, respectively. These applications propose changes to Technical Specification 3/4.5.2 ECCS Subsystems -
Tavg Greater Than or Equal to 3500F, Emergency Core Cooling Systems.
If you need additional information on this Technical Specifi cation change request, please let me know.
Very truly yours, Enclosures cc:
J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3
ASEA BROWN BOVERI April 30, 1991 CEOG-91-260 Operations Subcommittee Analysis Subcommittee (Task 582 Participants)
Subject:
Clarification to Test of CE NPSD-550
Attachment:
Clarification of Operator Error Probability Used in CE NPSD-550
Reference:
"Risk Evaluation of Removal of Shutdown Cooling System Auto-Closure Interlock," CE NPSD-550.
Gentlemen:
Attached for your information and use is a clarification to a specific section of the referenced report, i.e., quantification of operator error that leads to loss of shutdown cooling during refueling operations.
The need for the clarification was discovered during a review of the referenced report by Southern California Edison. Ruppert Weston (ABB-CE) has developed the attached clarification. Please call Ruppert at (203) 285-3262 if you have any questions on this information.
Sincerely, Peter R. Nelson Assistant Project Manager C-E Owners Group PRN/mnw cc J. W. Pfeifer, C-E P. W. Richardson, C-E ABB Combustion Engineering Nuclear Power Combustion Engineering, Inc.
1000 Prospect Hill Road Telephone (203) 688-1911 Post Office Box 500 Fax (203) 285-9512 Windsor. Connecticut 06095-0500 Telex 99297 COMBEN WSOR
CLARIFICATION OF OPERATOR ERROR PROBABILITY USED IN CE NPSO-550 The following is provided as clarification of the qualification of operator error that leads to loss of shutdown cooling during refueling operations.
As noted in CE NPSD-550 (Page 4-17), this type of operator error was explicitly modeled in the fault trees and quantified using expression (4-3).
Upon closer review, the value of 0.22 represents the probability that the operator errs given loss of shutdown cooling and not the conditional probability for the given expression. Consequently, the following modification to the operator error probability that was used in CE NPSD-550 is provided.
The probability of an operator erring while performing maintenance or test is obtained using the method described in Reference 12. It includes error of omission and failure to recover.
Omission Error:
HEP=
0.001 Operator errs in using written procedures Table 20-7 (Item #1)
And Recovery Error:
HEP=
0.1 Checker fails to detect error during maintenance or test operation Table 20-22 (Item #1)
The probability, that the operator errs and shutdown cooling is lost, is therefore.1.OOE-04. An error factor of 3.0 is assumed.
The operator probability used in CE NPSD-550 is approximately twice as large as this revised estimate. As shown in CE NPSD-550, this type of operator.
error is an insignificant contributor to the unavailability of shutdown cooling.
With the revised estimate for operator error, the contribution to shutdown cooling unavailability would become even less. Consequently, the results and conclusions.of CE NPSD-550 are still valid for the revised estimate of operator error probability.
OPERATIONS SUBCOMMITTEE R. Buzard, APS (Phoenix)
J. Hill, BG&E (Lusby)
G. C. Bischoff, ABB/C-E (Windsor)
R. Frigo, CPC (Covert)
M. Chisum, Entergy Operations-ANO (Russellville)
R. Starkey, Entergy Operations-Waterford (Killona)
C. Burton, FPL (Ft. Pierce)
G. Stowers, MY (Wiscasset)
S. Brinkman, NU (Waterford)
D. Trausch, OPPD (Ft.Cal)
D. Lokker, SCE (San Clemente)
John Hutchinson, FPL (Juno Beach) Subcommittee Sponsor
- Not a member, but receives correspondence ANALYSIS SUBCOMMITTEE B. Miller, APS (Phoenix)*
M. Radspinner, APS (Phoenix)
J. A. Mihalcik, BG&E (Lusby)
M. S. McDonald,.ABB (Windsor)
R. J. Gerling, CPC (Covert)
B. Daiber, Entergy Operations-AN0 (Russellville)
J. Holman, Entergy Operations-Waterford (Killona)
J. Perryman, FPL (Juno)
H. Jones, MY (Wiscasset)
T. Honan, NU (Berlin)
K. Holthaus, OPPO (Omaha)
M. McDevitt, SCE (Irvine)
P. Dietz, INPO (Atlanta)**
- Not a member, but receives all correspondence
- On distribution for meeting announcements/agenda transmittals