ML20087A596
| ML20087A596 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/19/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20087A590 | List: |
| References | |
| NUDOCS 9201090241 | |
| Download: ML20087A596 (2) | |
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SAFETY EVALUATION B_Y THE OFFICE OF NUCLEAR REACTOR REGULATION REL ATED TO AMENDMENT N05._16.5_ A!1D_,1.6_9__T0_ FACillTY OPERATING LICENSE NOS. DPR-44 and DPR-56 PHILADELPHIA ELECTRIC COMPANY PUBlitlERMCE~llttTRTC AND GAS COMPANY DELt1ARVA TDWER AND LIGTITtDf4 AW~~~
17EMlT1C C1TY ELttThR' TOM _PA!f PEACH _ BOTTOM ATOMIC POWER STATICNx, UNIT NOS. 2 AND 3 DOCKET N05. 5,0, _277_ MD__5_0_-278
1.0 INTRODUCTION
By letter dated July 2,1991, the Philadelphia Elactric Company, Public Servit.e Electric & Gas Company. Delmarva Power and Light Company and Atlantic City Electric Company (the lisnsees) submitted a request for changes to the Peach Bottom Atomic Power Station, Unit Hos. 2 and 3, Technical Specifications (TS). The requested changes would revise the Emergency Service Water Surveillance Test method for demonstrating pump operability from a measurement of pump shut-ofi discharge pressure to a measurement of pump flow.
2.0 EVALUATION The licensee stated in its July 2,1991 submittal that the purpose of the requested TS Change is to minimize the adverse affects of the current method of testing and to provide for increased pump reliability. Present Peach Bottom Atomic Power Station, Units 2 and 3, Technical Specification surveillance requirements for the Emergency Service Water (ESW) System provide for demonstrating the operability of the ESW pumps every three months. Under the current Technical Specifications, pump operability is demonstrated by measuring the pump's discharge pressure at shut-off head. Pump operability is considered satisfactory if the discharge pressure at shut-off head is greater than or equal to 5a psig.
The current surveillance test is conducted by establishing a flow path through an Emergency Diesel Generator (DG) cooler, manually starting the ESW pump and, once the pump is running, shutting the DG cooler discharge valve.
In this condition, there is no flow through the ESW pump and shut-off hecd discharge pressure is measured. Operatiun of the Pump at shut-off head can cause excessive vibration of the pump and set up internal recirculation flows which, over time, can seriously degrade the hydraulic parts and bearings of the pump. The ESW pump is of centrifugal construction, specifically it is a single stage, vertical turbine pump.
Centrifugal pumps require a minimum flow through the pump in order to cool the pump while it is in operation.
l Operation of the ESW pump with the flow blocked for testing could lead to overheating of the pump.
9201090241 911219 PDR ADOCK 05000277 p
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.. In order to implement the proposed test method, the licensee has installed ultrasonic flow measuring devices, which measure pump flow, downstream of the ESW pumps as a means of verifying pump operability. The results of the proposed test method will provide an integrated indication of pump operability by providing data with the system in a flow-through configuration. The test method proposed by the licensee conforms to ASME Boiler and Pressure Vessel Code,Section XI, Rules for Inservice Inspection of fluclear Power Plant Components.
The staff has reviewed the proposed change in ESW pump testing niethodology to flow measurement and finds it acceptable. The proposed change will reduce pump degradation due to testing and will provide for a more reliable pun'p.
3.0 STATE C0tiSULTATION In accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 EllVIRONt1 ENTAL CONSIDERATION The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes the surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significcnt hazards consider-ation, and there has been no public comment on such finding (56 FR 41585).
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in Iq,,CrR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Joseph W. Shea Date: December 19, 1991