ML18139B490
| ML18139B490 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/07/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18139B489 | List: |
| References | |
| TASK-2.E.1.2, TASK-TM NUDOCS 8108240333 | |
| Download: ML18139B490 (3) | |
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SAFETY EVALUATION SURRY UNITS.I & 2 - AUXILIARY FEEDWATER AUTOMATIC INITIATION AND FLOW INDICATION ACTION PLAN ITEM II.l.1.2 INTRODUCTION AND
SUMMARY
To improve the reliability of Auxiliary Feedwater Systems (AFWS) at pressurized water reactor (PWR) facilities, th~ staff is r~quiring licensees to upgrade the system \\'!'here necessary to ensure safety grade automatic initiation and flow indication.
The criteria for this ~pgrading are contained in NUREG-0737 (Clarifications of TMI Action Plan Requirements),Section II.E.1.2.
The evaluation of the Surry Units 1 & 2 AFWS design was performed for the NRC by Franklin Research Center (FRC) as part of a technical assistance contract program.
The fesults of the FRC evaluation are reported in the attached Technical Evaluation Report (TER-C5257 - 277/315).
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Based on our review of the FRC TER, we conclude that the AFW automatic initiation and flow.indication designs are acceptable, wtth exceptions as noted below.
EVALUATION The attached TER provides a technical evaluation of the electrical, instrumentation, and control design aspects of the Surry Units 1 & 2 AFWS with regard to automatic initiation and flow indication.
In addition to the design description contained in the TER, it should be noted that the a.c. motor driven pumps and valves in the AFWS are included ii the automatic actuation of loads onto the emergency buses.
- Also, no single *failure could be found which would prevent more than one of the two parallel valves (normally closed) in the steam supply line for the turbine driven auxiliary feedwater pump from opening on an automatic initiation signal.
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The environmental qualification of safety related systems including AFWS circuits and components is. being reviewed by the Environmental Qualification Branch as part of their review of licensee responses to "Guidelines for Evaluating Environmental Qualification of Class lE Electrical Equipment in Operating Reactors," issued to' the licensee in NRR letter dated March 5, 1980.
In order to adequate1y determine from the control room the performance of the AFWS, steam generator level instrumentation is used, in addition to flow indication.
,The requirements for this ste9m.genera.tor level instrumentation are specified in Regulatory Guide 1.97, Revis.ion 2 (Regulatory Guide 1.97 - "Instrumentation for Ligh~-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions*
During and Following an Accident").
The steam generator level instrumentation at Surry must be in conformance with these requirements and implemented in accordance with the schedule indicated in the referenced ReguTatory Guide.
CONCLUSION Based on our review of the Franklin Research Center TER, we agree with their findings that the Surry Units 1 & 2 AFWS automatic initiation and flow indication comp_ly vdth the staff's long term safety grade requirements with the following exce~tions:
- 1.
During monthly testing of the low:low steam generator level trip, the*
auxiliary'feedwater pumps are locked out by placing pump control in the p~ll-to-lock position.
Since this action precludes automatic initiation of the AFWS, this fact should be continuously indicated in the control room in accordance vdth IEEE Standard 279-1971, Section 4..13 (Indication of Bypasses).
- 2.
The AFW flow transmitters presently used at Surry are not safe~y grade.
Safety grade AFW flow transmitters should be installed consist2nt with NUREG-0737.
In addition, surveillance requirements regarding the testing of the AFW flow channels
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should be included in the Surry Units 1 & 2 Technical Specifications~
The test frequencies should be consistent with those of other safety related instrument channels (e.g., those used to generate protective actions).