ML20154Q648
| ML20154Q648 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/18/1986 |
| From: | Butterfield L COMMONWEALTH EDISON CO., WESTINGHOUSE OPERATING PLANTS OWNERS GROUP |
| To: | Novak T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20154Q650 | List: |
| References | |
| RTR-NUREG-1154 OG-178, NUDOCS 8603210214 | |
| Download: ML20154Q648 (3) | |
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- N CommonwIlth Edison i
72 west Adams street. chicago. Ilknois J Address Reply to: Post Office Box 767 Nd Chicago, Illinois 60690 OG-178 March 18, 1986 Ref: OG-168, dated December 6,1985 Mr. Tom Novak Director (Acting) Licensing PWR-A Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Phillips Building Washington, D.C.
20555
Dear Mr. Novak:
Westinghouse Owners Group Final Report on WOG Davis-Besse Evaluation Program In December 1985, the referenced letter informed the NRC staf f that the WOG had undertaken a program to evaluate the NUREG-1154 findings and assess their relevance to WOG plants.
In order to accomplish this task the WOG established the Davis-Besse working group whose primary purpose was to develop and document the WOG position on each of the potential generic issues stemming from the Davis-Besse event. The WOG Davis-Besse Program is now complete, and the report documenting the WOG position on the Davis-Besse event is enclosed.
It was the general conclusion of the WOG that the fundamental design differences between Davis-Besse and WOG plants have two important impacts.
1.
These fundamental design differences preclude the specific Davis-Besse sequence of events from occurring at a WOG plant.
2.
These design differences, prove beneficial to the ability of a Westinghouse NSSS plant to respond to a loss-of-feedwater transient, and thus lessen the safety significance of the Davis-Besse type issues.
when applied to Westinghouse designs.
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0G-178 March 18,1986 The design differences are described in more detail in the attached report, but generally fall into four areas:
Steam Generator Design Secondary Side Reactor Trip j
Auxiliary Feedwater System Diversity
" Smart" Control Systems The W0G recognized that the nature of the human errors and the type of equipment failures which occurred during the Davis-Besse event could occur at a W0G plant. Therefore, the primary focus of the WOG Davis-Besse Program was 1
the evaluation of the following eleven potential issues (described in the i
enclosed report) stemming from the Davis-Besse event.
1.
Plant Security Features 2.
Adequacy of Emergency Procedures 3.
Reliability of Motor Operated Valves 4.
Safety System Testing 5.
Acceptability of Current Safety Assessment Methods 6.
Adequacy of Emergency Notifications 7.
AvaiIabiiity of the Shift Technical Advisor 8.
Resolution of Equipment Deficiencies 9.
ReIiability of AFW Pump Turbines 10.
Adequacy of Control Room Instrumentation 11.
Rellability of Pilot-Operated Rellef Valves in the course of reviewing the Davis-Besse potential issues, the WOG identified (three) issues which may warrant further consideration.
For the i
following issues, the WOG is identifying what portions of these issues the WOG can address on a generic basis.
l ReIlability of AFW Pump Turbines Adequacy of Safety System Testing ReIiability of Motor-0perated Valves The " Reliability of Motor-Operated Valves" issue has already resulted in an additional WOG program to develop a methodology to address action (a) of Bulletin 85-03 " Motor-0perated Valve Common Mode Failures During Plant Transients Due to improper Switch Settings".
If the WOG identifies portions of the remaining two issues currently under consideration, which can be addressed on a generic basis, then potential l
programs will be developed to address these issues.
The WOG will keep the NRC abreast of the status of these issues.
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0G-178 March 18,1986 The WOG does not consider it necessary to pursue any additional generic action on the remaining eight issues.
This report completes the WOG Davis-Besse Evaluation Program.
If you have questions, or wish to discuss in further detail any aspects of the program or the position, please contact me.
Thank you.
Very truly yours, w M(
L.D. Butterfield, Chairman Westinghouse Owners Group LDB:dac attachment cc: WOG Representatives Davis-Besse Working Group I
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