ML20081F217

Safety Evaluation Supporting Amends 94 & 84 to Licenses NPF-10 & NPF-15,respectively

ML20081F217
Person / Time
Site:	San Onofre
Issue date:	06/03/1991
From:	Kokajko L Office of Nuclear Reactor Regulation
To:
Shared Package
ML20081F210	List: ML20081F206 ML20081F217
References
NUDOCS 9106070215
Download: ML20081F217 (4)

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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 94 AND B4 TO FACILITY OPERATING LICENSE N05. NPF-10 AND NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE, CAllFORNIA THE CITY OF ANAHEIM, CALIFORNIA SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NOS. 2 AND 3 DOCKET NOS. 50-361 AND 50-360

1.0 INTRODUCTION

By letter dated A or the licensee) pril 8,1991, Southern California Edison Company, et al., (SCE requested an amendment to Facility Operating License Nos.

NPF-10 and NPF-15 that authorize operation of San Onofre Nuclear Generating Station, Unit Nos. 2 and 3 in San Diego County, California. Specifically, the proposed amendment revised the Updated Final Safety Analysis Report (UFSAR)

Section 9.1.3, " Spent Fuel Pool Cooling and Cleanup System," to allow the use of the shutdowr. cooling system as an alternate means of cooling the spent fuel pool.

The spent fuel pool (SFP) cooling system for San Onofre Nuclear Generating Station, Units 2 and 3, consists of two pumps, each powered from the class IE electrical system, and two heat exchangers. The SFP cooling heat exchan are cooled by the non-critical loop of the component cooling water (CCW)gers system.

The non-critical loop is supplied by either of two trains of the CCW system.

Each CCW heat exchanger is cooled by an independent train of the salt water cooling (SWC) system which transfers heat to the ultimate heat sink, the Pacific Ocean.

The CCW system has two 100 percent capacity train aligned pumps and one 100 percent capacity swing pump, each powered from the class IE electrical system, and two 100 percent capecity heat exchangers. The two independent critical loops are interconnected with a cross tie downstream of the heat exchangers and a cross tie upstream of the component cooling water pumps.

Isolation valves for the two independent critical loops are provided in these two cross ties. The non-cr ical loop piping is connected between these cross ties such that it can be supplied from either critical loop. Each CCW critical loop operates indepentjently of the other, including when the opposite loop cross 9106070215 01060~1 PDR ADOCK 05000361 P

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2 train isolation valves are isolated for maintenance. However, mair,tenance to be performed on the cross-train isolation valve will require the removal of the SFP cooling system from service. Therefore, an approved alternate cooling system for the SFP is needed. Consequently, by letter dated April 8,1991, the licensee requested an amendment to f acility Operating License Nos. NPF-10 and NPF-15.

The licensee's application proposed to revise the Updated Final Safety Analysis Report (UFSAR) Section 9.1.3, " Spent Fuel Pool Cooling and Cleanup Systcm," to allow the use of the shutdown cooling system (SDC) system as an alternate means of cooling the SFP when the Technical Specification (TS) do r.ot require the SDC system to be operable to cool the reactor core.

Currently, the SDC system has been approved only as a backup system and may only be used to cool the SFP if the SDC is available and the normal SFP cooling system fails.

The SDC system has two 100 percent capacity heat exchangers, each cooled by a CCW critical loop.

Flow through the SDC heat exchangers is provided by two low pressure safety injection pumps; each pump can be aligned to either SDC heat exchanger. The syster can be aligned to either the reactor coolant system or the SFP. The process generally consists of the reversal of blind spectacle flanges, a fill and vent of the suction and discharge lines f rom the refueling water storage tank, ard a valve alignment.

2.0 EVALUATION 2.1 Proposed changes to San Ono're Unit Nos. 2 and 3 UFSAR Section ".1.3.2,

" System Description" The licensee propcsed to add the following paragraph to Section 9.1.3.2:

"The shutdown cuoling system is a safety related, and seismically qualified system which is powered by a class 1E electrical system. The cooling capacity of 1 trair of the shutdown cooling systerr is sufficient to maintain the spent fuel pool temperature lower than the spent fuel pool cooling system. During a full core offload from the reactor vessel, the shutdown cooling system is not required to be operable for reactor core cooling.

The shutdown cooling system (consisting of 1 LPSI [ low pressure safety injection]

pump, I heat exchanger, flow path to and from the SFP, and the associated diesel generator) may be aligned to cool the spent fuel pool."

The licensee stated that the SDC system will only be used during a complete core off-load when current TS do not require SDC system operability for reactor core cooling.

We concur with licensee's rationale and find the above proposed changes to the UFSAR acceptable.

2.2 Proposed changes to San Onofre Unit Nos. 2 and 3 UFSAR Section 9.1.3.3, "Saf ety Evaluation" l

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. The licensee proposed to reword the second to the last paragraph of Section 9.1.3.3 as follows to reflect the above proposed use of SDC system as an alternate means of cooling the spent fuel pool:

Current Wording:

"The shutdown cooling system, if available, may be used as backup cooling for the spent fuel pool when the full core is removed from the reactor vessel and this covers the possibility referred to under the remarks column of table 9.1-3."

Proposed Wording:

"The shutdown cooling system, if available, may be used as 6n alternative means of cooling the spent fuel pcol when the full core is removed from the reactor vessel.

This covers the possibility referred to under the remarks column of table 9.1 -3. "

Based on our review of licensee's ratiorale, we fir.d the above proposed rewcrding of UFSAR acceptable.

2.3 Conclusion Based upon the licensee's letter dated April 8,1991, and the information presented ab've, the staff finds the proposed amendment to the San Onofre Nuclear Gencrating Station, Unit Nos. 2 and 3, (Facility Operating License Nos. NPF-10 and NPF-15) acceptable. Therefore, staff approval to authorize Southern California Edison Company, et al., to revise the Updated Final Safety Analysis Report to reflect the use of the shutdown cooling system as an alter-nate means to cool the spent fuel pool is grented.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendment. The State of ficial had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to the installation or use of a facility compunent located within the restricted area as defined in 10 CFR Part 20, or changes a surveillance requireraent. The NRC staff has detenniried that the amendments involve no significant increase in the amounts, and no significant change iri the types, of any effluent. that may be released offsite, l

and that there is no significar,t increase in individual or cumulative occupa-tionr1 radiation exposure. The Commission has previously issued a proposed i

finding that the amendments involve no significant hazards consideration, and there has beer, no public comment on such finding.

Accordingly, the amendments l

4 meet 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 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 endangert:d 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 amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors:

David H. Shum Lawrence E. Kukajko Date: June 3,1991

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