ML14183A147
| ML14183A147 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 09/05/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML14183A146 | List: |
| References | |
| NUDOCS 8909120208 | |
| Download: ML14183A147 (2) | |
Text
,tpg RE J UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFEY. EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 123 TO FACILITY OPERATING LICENSE NO. DPR-23 CAROLINA POWER & LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261
1.0 INTRODUCTION
By letter dated April 27, 1989, the Carolina Power & Light Company (CP&L) submitted a request for changes to the H. B. Robinson Steam ElectrikRlant, Unit No. 2 (HBR -2) Technical Specifications (TS) to add surveillance requirements to Table 4.1-3 for the automatic bus transfers on the -a1xiiar feedwater system (AFWS) valve V2-16A and service water (SW) system ViaW' V6-16C. The proposed change would require a refueling interval tes thermal and magnetic trip of elements of the molded case circuit (MCCB) associated with valves V2-16A and V6-16C.
2.0 EVALUATION Related to TMI Action Plan (NUREG-0737), Item II.E.1.2, the NRC staff reviewed the adequacy of the automatic initiation of the AFWS. The staff's evaluation found that with the exception of the presence-of an automatic bus transfer (ABT) device the AFWS complies with the staff's long-term safety grade requirements. This ABT is designed to transfer the power supply for the AFWS' motor driven, pump discharge valve No. V2-16A from its normal train A supply (Bus El) to an alternative power source (train B, Bus E21 if the normal power source becomes unavailable.
The staff's concern about the ABT device is that it creates an increased potential for common mode failures by providing an automatic connection between redundant load groups. CP&L maintains that a potential common mode failure is unlikely since the circuit breaker protection scheme employed is coordihated for a worst case fault and-would act to prevent the transfer of any fault. In support of this position, CP&L submitted, by letter dated June 14, 1985, the results of an "ABT Study."- CP&L states that the study shows that circuit breaker trip settings are properly sequenced so that breakers which are electrically closest to a fault at the valve will operate to isolate the fault prior to any impact being felt by upstream protective devices in either load train. Therefore, CP&L asserts that adequate protection against common mode failures exists primarily because of the MCCB used as isolation devices between redundant buses and because of proper coordination between MCCB and their upstream breaker within each bus train.
PDR ADOCK 05F000261 PPD
-2 To ensure that the circuit breaker operation will occur as anticpated, the staff recommended implementation of surveillance procedures which require periodic testing of the instantaneous and thermal overload trip elements in the MCCB. The proposed TS would add the recommended surveillance requirements for the AFW header discharge valve V2-16A and is, therefore, acceptable for providing the operability demonstration. The SW system isolation valve, V6-16C is identified by CP&L to fall under the same ABT category and is included in the surveililance requirement. The staff finds the inclusion of V6-16C to be appropriate.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment changed a surveillance requirement with respect the use of facility components located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released off site; and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration, and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 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 this amendment.
4.0 CONCLUSION
The Commission made a proposed determination that this amendment involves no significant hazards consideration, which was published in the FEDERAL REGISTER (54 FR 25370) on June 14, 1989, and consulted with the State of North Carolina. No public comments or requests for hearing were received, and the State of North Carolina did not have any comments.
The Staff 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, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Ronnie Lo Dated: September 5, 1989