ML20246J505
| ML20246J505 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 07/10/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20246J503 | List: |
| References | |
| NUDOCS 8907170389 | |
| Download: ML20246J505 (4) | |
Text
{{#Wiki_filter:_ ~4 f *** %g 3 - c, UNITED STATES j } -{ NUCLEAR REGULATORY COMMISSION .m 7,; "- j WASHINGTON, D. C. 20555 S / %..v... " SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0. 38 TO FACILITY OPERATING LICENSE NO. NPF-47 GULF STATES UTILITIES COMPANY RIVER BEND STATION, UNIT 1 DOCKET NO. 50-458
1.0 INTRODUCTION
By letter dated August 26, 1986 as modified May 2, 1989 and supplemented May 25, 1989, Gulf States Utilities Company (GSU) (the licensee) requested an amendment to Facility Operating License No. NPF-47 for the River Bend Station, Unit 1. The prcposed amendment would add Technical Specifications (TSs) for the Suppression Pool Pumpback System (SPPS). The SPPS is designed to control any post-LOCA leakage from the emergency core cooling system in the crescent area of the auxiliary building at elevation 70 feet, by returning this leakage to the suppression pool. During normal operation, the system pumps floor and equipment drainage to the radwaste building. The SPPS consists of two sumps, each of which has two pumps. Selection of the option to pump back to the suppression pool is by means of opening a motor-operated valve. Opening this valve automatically closes the air-operated valves to the radwaste system. The piping from the isolation valves to the suppression pool interfaces at the high pressure core spray line. Leakage could occur in two sections of the ECCS piping. Leakage in the portion of the piping from the outboard containment isolation valve to the crescent room boundary can be stopped by closing the isolation valve. Leakage from the cor.tainment boundary to the outboard isolation valve is postulated to be as high as 50 gpm (the design basis for the SPPS). The licensee estimates that without initiating the SPPS it would take 40 hours to lower the suppression pool to the minimum level for ECCS pump operability at this leakage rate. Each of the four SPPS pumps is capable of pumping at least 50 gpm. Thus, should a leak occur in this area following a LOCA, the SPPS will be aligned to pump the water to the suppression pool to provide additional time for the operator to identify source of the leakage while maintaining suppression pool water level and preventing excessive buildup of water in the auxiliary building. The NRC staff approved the SPPS in Section 9.3.3 of Supplement No. 3, and Section 3.10.1.6 of Supplement No. 5 to the Safety Evaluation Report relcted to the operation of River Bend Station, NUREG-0989 (Suppitment No. 3, August 1985, and Supplement No. 5, November 1985). 8907170389 890710 PDR ADOCK 05000458 p PDC
1 , 2.0 EVALUATION This section of the Safety Evaluation evaluates the licensee's proposed .TSs for the SPPS. 2.1 Limiting Condition for Operation (LCO) Item c. would be added to the LCO in TS 3.5.3. Item c states that the suppression pool shall be operable with two operable SPPS subsystems consisting of at least one operable crescent area sump pump and an operable flow path to the suppression pool. A footnote is also included to clarify that the SPPS is not required to be operable when the suppression pool is not required to be operable. The staff finds that this LC0 provides reasonable assurince that both subsystems will be available to pump back any post-LOCA crescent area leakage to the suppression pool. This LCO is acceptable. 2.2 Action Statement Items c. and d. would be added to the ACTION statement in TS 3.5.3. With one SPPS subsystem inoperable, the ACTION statement would require that the inoperable subsystem be restored to operable condition within 31 days; otherwise, the remaining subsystem must be demonstrated operable at least once per 31 days. Operability of the remaining system is to be demonstrated by performing a functional test of the crescent area sump pump and demonstrating that the associated ficw path can be aligned to the suppression pool. The pumping capacity of one pump is adequate to control the design basis 50 gpm leakage. The licensee has also requested relief from the provisions of TS 3.0.4 to allow startup and operation with one SPPS subsystem inoperable when operability of the suppression pool is required. TS 3.0.4 states: 3.0.4 Entry into an OPERATIONAL CONDITION or other specified condition shall not be made unless the conditions for the Limiting Condition for Operation are met without reliance on provisions contained in the ACTION requirements. This provision shall not prevent passage through or to OPERATIONAL CONDITIONS as required to comply with ACTION requirements. Exceptions to these requirements are stated in the individual Specifications. As previously discussed, the SPPS is required (1) in the event that a LOCA occurs, and (2) there is leakage between the containment boundary to the outboard isolation valve. Only one SPPS subsystem is required should these two events occur and the proposed ACTION statement requires that at least one subsystem be operable. Oper-ability of the ECCS equipment would not be affected by leakage in the crescent area because this equipment is located in watertight cubicles. Failure of the SPPS alone does not result in the failure of the suppression pool or the ECCS. L___
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. In the May 25, 1989 submittal, the licensee states that they do not condene the startup of the plant with safety features inoperable and they will continue to place a high priority en the maintenance required to keep safety features-operable. The licensee's review of past main.tenance on the pumps and valves involved in the SPPS identified a total of 7 maintenance work orders on the pumps, all of which were given high priority. Four maintenance work orders were identified on the motor operated valve; 3 were given high priority and the remaining one was for routine maintenance. With both SPPS subsystems inoperable, one SPPS subsystem would be required to be restored to operable status within seven days or in Operational Condition 1, 2, or 3, the reactor is to be placed in at least hot shutdown within the next 12 hours and cold shutdown within the next 24 hours. In operational condition 4 or 5 (unless the suppression pool is not required to be operable), one alternate pumpback method is to be provided and demonstrated operable within 24 hours and'at least once per 24 hours thereafter; otherwise all core alterations and all operations that have a potential for draining the reactor vessel are to be suspended. The reactor mode switch'is to be locked in the shutdown condition for this case and Primary Containment Integrity-Fuel Handling is to be established within 8' hours. l l The staff finds that the proposed ACTION statement and the relief from the provisions of TS 3.0.4 are acceptable. 2.3 Surveillance Requirements (TS 4.5.3.3) The proposed surveillance requirements would require demonstration, at least once per 92 days, that the SPPS is operable by(2)) verifying (1 verifying l that each crescent area sump pump delivers 50 gpm, and 1 that the flow path can be aligned to the suppression pool. The staff finds that these surveillance requirements are adequate to j demonstrate operability; accordingly, they are acceptable. 2.4 Bases The licensee has proposed to add a BASES section for the SPPS. The proposed section provides a narrative basis for the proposed TSs. The staff finds the BASES section acceptable. q
3.0 ENVIRONMENTAL CONSIDERATION
The amendment involves a change in the installation or use of a facility component 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 b? released offsite, and that there is no significant l E 1
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- c increase in individual or cumulative occupational' radiation exposures.
The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for cLiegorical exclusion set forth in 10 CFR Section 51.22(c)(9). Pursuant to IV CFR 51.22(b), no environmental impact statement or environ-mental assess:nent need be prepared in connection with the issuance of the amendment.
4.0 CONCLUSION
The staff has concluded, baned on the considerations discussed above, that: -(1) there is reasonable-assurance that the health and safety of the public - will not be endangered by rperation in the proposed r.anner, and (2) such activities will be conducted in. compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public. The staff therefore concludes that the proposed changes are acceptable. Dated: July 10, 1989 Principal Contributors: W. Paulson-I ( .,.}}