ML20045E701
| ML20045E701 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 06/28/1993 |
| From: | Cross J PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20045E702 | List: |
| References | |
| NUDOCS 9307020336 | |
| Download: ML20045E701 (2) | |
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i Portland General ElechicCompany James E. C;ross Vice President and Chief Nuclear Officer June 28, 1993 Trojan Nuclear Plant Docket 50-344 License NPF-1 U.S. Nuclear Regulatory Commission Atta: Document Control Desk Washington DC 20555
Dear Sirs:
Responae_Ao_RraL L 1912_AccidenLSe.quen cee_frecuraar_Renatt Your letter of June 10, 1993 transmitted a copy of an accident sequence precursor (ASP) analysis of the Trojan Nuclear Plant Licensee Event Report (LER) number 344/92-020. We have reviewed the preliminary analysis as suggested and provide the following comments for consideration.
In general, Portland General Electric Company (PGE) has no adverse comments regarding the report characterization of the possible plant responses to the event or the representation of plant safety equipment configuration.
It should be noted, however, that PGE cannot confirm the computer modeling assumptions of the Oak Ridge National Laboratory (ORNL) risk assessment for this event.
Trojan's Individual Plant Examination (IPE) submittal does list the Loss of Main Feedwater Event Total Frequency as 7.15E-07.
The preliminary analysis modeling assumptions (Item B.20.4) describes this event as a reactor trip with loss of feedwater and one auxiliary feedwater (AFW) pump unavailable. The non-safety related AFW pump was assumed capable of providing steam generator (S/G) cooling following a manual start. However, the analysis also assumed that no procedures were l
available for this action. This assumption is incorrect. Operator j
response to a loss of feedwater event, including the failure of the auxiliary feedwater pumps to start, is specified in Functional-Restoration Instruction (FR-H.1), " Response to Loss of Secondary Heat Sink" and Emergency Instruction (EI-0), " Reactor Trip, Safety Injection, and Diagnosis".
Off-Normal Instruction (ONI) 55, " Operation of Electric Auxiliary Feedwater Pump Supplied by Emergency Diesel Generator" was also available to provide procedural steps necessary to start the electric AFW pump if of fsite power was not available during the performance of FR-H.1.
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Document Control Desk June 28, 1993 Page 2 Copies of the appropriate sections of the procedures are attached for your review. Trojan's Nuclear Plant Operators are also trained for various loss of feedwater events in both classroom lecture and the plant simulator.
It is important this information be considered in the final report modeling assumptions.
Should you have any questions, please contact T. D. Walt at (503)550-5527.
Sincerely,
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i Attachments c:
Mr. Bobby H. Faulkenberry Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. David Stewart-Smith State of Oregon Department of Energy Mr. J. F. Melfi NRC Resident Insi ctor Trojan Nuclear Plant