ML13326A910
| ML13326A910 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/29/1992 |
| From: | Ray H Southern California Edison Co |
| To: | |
| Shared Package | |
| ML13326A909 | List: |
| References | |
| NUDOCS 9211040050 | |
| Download: ML13326A910 (9) | |
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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION Application of SOUTHERN CALIFORNIA EDISON
)
COMPANY and SAN DIEGO GAS & ELECTRIC COMPANY
)DOCKET NO. 50-206 for a Class 104(b) License to Acquire,
)
Possess, and Use a Utilization Facility as
)
Amendment Application Part of Unit No. 1 of the San Onofre Nuclear
)NO.
207 Generating Station
)
SOUTHERN CALIFORNIA EDISON COMPANY and SAN DIEGO GAS & ELECTRIC COMPANY, pursuant to 10 CFR 50.90, hereby submit Amendment Application No. 207.
This amendment application consists of Proposed Change No. 259 to the Unit 1 Operating License No. DPR-13. Proposed Change No. 259 deletes the automatic start capability requirements for the diesel generators in Modes 5 and 6 contained in the Technical Specifications incorporated in Facility Operating License No. DPR-13 as Appendix A.
Technical Specification 3.7.2.b requires operability of one diesel generator capable of automatic start in Modes 5 and 6. However, the automatic start capability of the diesel generators has no safety function in Modes 5 and 6.
The proposed change will remove this requirement from Technical Specification 3.7.2.b, thus eliminating the need to perform special diesel generator surveillance tests to demonstrate the automatic start capability following the upcoming permanent shutdown of SONGS 1. The proposed change will have no adverse impact on the core decay heat removal capability during shutdown, or on the ability of the plant to remain in a safe shutdown condition for an extended period of time. The proposed change is consistent with Westinghouse Standard Technical Specification requirements for electrical power systems during shutdown.
- -92f040050 92T7O29 PDR ADOCK 05000206 PDR
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-2 Based on the significant hazards analysis provided in the "Description and Significant Hazards Consideration Analysis of Proposed Change No. 259 to the Technical Specifications," it is concluded that (1) the proposed change does not involve a significant hazards consideration as defined in 10 CFR 50.92, and (2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change.
-3 Respectfully submitted, SOUTHERN CALIFORNIA EDISON COMPANY By:
Ha -old B. Ray 4
Senior Vice Pre sAent State of California County of Orange On
/0before me, 34,,A3d,9 A. RcCq,--Y~
e personally appeared ZA##OLD Z.
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, personally known to me to be the person whose name is subscribed to the within instrument and acknowledged to me that he executed the same in his authorized capacity, and that by his signature on the instrument the person, or the entity upon behalf of which the person acted, executed the instrument.
WITNESS my hand and official seal.
OFFICIAL SEAL BA..
.RBAR A MC CARTHY Notoy Puic~-CoforNo ORANG COUNW Signature
- c.
James A. Beoletto Attorney for Southern California Edison Company By:
Ja
.'e'041iffil
DESCRIPTION AND SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS OF PROPOSED CHANGE NO. 259 TO THE TECHNICAL SPECIFICATIONS FACILITY OPERATING LICENSE NO. DPR-13 This is a request to revise Technical Specification 3.7.2, "ELECTRICAL SUPPLY:
SHUTDOWN," paragraph b, included as part of Appendix A to the San Onofre Nuclear Generating Station Unit 1 (SONGS 1) Facility Operating License.
This change will remove the requirement for the SONGS 1 diesel generators to have the automatic start capability in Modes 5 and 6.
Existing Technical Specifications See Attachment 1.
Proposed Technical Specifications See Attachment 2.
Description of Change Paragraph b of Technical Specification 3.7.2, "ELECTRICAL SUPPLY: SHUTDOWN" establishes operability requirements for diesel generators while in Modes 5 and 6. Specifically, Technical Specification 3.7.2.b requires that to maintain the Station in the shutdown or refueling condition for extended periods (MODES 5 and 6), one diesel generator must be operable which is capable of automatic start. The proposed change will delete reference to the automatic start requirements for the diesel generator in Modes 5 and 6.
Paragraph F of Technical Specification 4.4, "EMERGENCY POWER SYSTEM PERIODIC TESTING," provides surveillance requirements for the diesel generators and the Safeguards Load Sequencing Systems (SLSS) during shutdown. According to current Specification 3.7.2.b, the associated surveillance of the diesel generators must be performed to demonstrate automatic start capability in Modes 5 and 6 in accordance with Specification 4.4.F. However, as discussed in the following sections, the automatic start capability of the diesel generators has no safety function in Modes 5 and 6. Removal of this requirement from Specification 3.7.2.b will eliminate the need to perform special diesel generator surveillance tests to demonstrate the automatic start capability following the upcoming permanent shutdown of SONGS 1.
The proposed change is consistent with the Westinghouse Standard Technical Specification (STS) 3.8.1.2 (dated May 15, 1978 and subsequent revision dated July 27, 1981) for the minimum A.C. electrical power source operability requirements during shutdown.
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Discussion BACKGROUND The SONGS 1 Technical Specifications for electrical power systems during shutdown were added in 1983 in response to an agreement with the NRC following a loss of all AC power at SONGS 1 on April 22, 1980.
The required actions to be taken resulting from the agreement were documented in a letter from the NRC on April 23, 1980 (see Reference 1).
These included the following:
"Effective immediately you will implement requirements similar to the standardized Technical Specification for Westinghouse PWRs (Specification 3.8.1.2, dated May 15, 1978) which requires as a minimum one source of offsite electrical power and one diesel generator (capable of automatic start) to be operable."
We submitted Amendment Application No. 92 on August 27, 1980 (see Reference 2) requesting revision to Technical Specification 3.7, "AUXILIARY ELECTRICAL SUPPLY," to implement the above requirements. Amendment No. 68 was issued on May 3, 1983 (see Reference 3) requiring operability of one diesel generator capable of automatic start during cold shutdown or refueling conditions.
(Subsequent amendments have revised Technical Specification 3.7 to address the electrical supply requirements during operation and shutdown in separate sections.)
AUTOMATIC START CAPABILITY REQUIREMENTS IN MODES 5 AND 6 In the event of a Safety Injection System signal concurrent with a Loss of Power signal (SISLOP), the SLSS automatically starts the diesel generators and automatically closes the diesel generator output breakers to the 4160-V AC buses. Although currently required by the Technical Specifications, the diesel generator automatic start capability has no safety function in Modes 5 and 6.
In Modes 5 and 6, the diesel generators are only required for decay heat removal and do not carry ECCS loads. Regardless of the automatic start capability, operator action is necessary to close the diesel generator breakers in Modes 5 and 6 for decay heat removal, and adequate time is available for the operator to initiate decay heat removal in these modes.
Consequently, the automatic start capability of the diesel generators does not provide any safety benefit in Modes 5 and 6. Eliminating this capability in Modes 5 and 6 will not degrade the decay heat removal capabilities in these modes.
In specifying that the diesel generator be capable of automatic start, the NRC sought (see Reference 1) to make SONGS 1 specifications for electrical power systems during shutdown similar to those of Westinghouse STS 3.8.1.2 (dated May 15, 1978).
However, Westinghouse STS 3.8.1.2 dated May 15, 1978 did not contain the automatic start requirement for the diesel generator. This requirement was also not included in the more recent version of the STS 3.8.1.2 dated July 27, 1981.
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DIESEL GENERATOR SURVEILLANCE REQUIREMENTS Technical Specification 4.4.F contains surveillance requirements to ensure operability of the diesel generators and the SLSS. These include requirements for testing the diesel generators for performance during a simulated occurrence of Safety Injection System signal concurrent with Loss of Offsite Power signal (SISLOP) during shutdown. The SISLOP test includes demonstration of the diesel generator capability for automatic start and loading upon receiving the SISLOP signal (Specification 4.4.F.1.b).
Technical Specification 4.4.F is intended to apply only to SISLOP functions.
Although SISLOP functions are not applicable in Modes 5 and 6, the current Technical Specification 3.7.2.b would require a separate surveillance to demonstrate the automatic start capability in Modes 5 and 6. As discussed earlier, automatic start capability has no safety function in Modes 5 and 6.
Operator action is required to initiate decay heat removal, and no immediate operator action is required to start or load the diesels for this purpose.
Furthermore, the equipment on which the test would be performed would no longer be needed following the upcoming permanent shutdown of SONGS 1.
Consequently, performing a SISLOP test as described in Specification 4.4.F in Modes 5 and 6 would constitute an unnecessary burden. The proposed change to Specification 3.7.2.b will eliminate this burden.
Significant Hazards Consideration Analysis In accordance with 10CFR50.91(a)(1), the following analysis is provided to demonstrate that the proposed change does not represent a significant hazards consideration. According to 10CFR50.92(c), the proposed change discussed above is deemed to involve a significant hazards consideration if there is a positive finding in any one of the following areas:
- 1. Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequences of an accident previously.evaluated?
Response: No The proposed change to Technical Specification 3.7.2.b will eliminate the automatic start requirements for the diesel generators in Modes 5 and 6.
Since SIS is not required in Modes 5 and 6, and since no immediate operator action is needed for core decay heat removal, there is no need for the automatic start capability for the diesel generators in Modes 5 and 6 and the associated surveillance.
The automatic start capability of the diesel generators has no safety function in Modes 5 and 6. The only accident with any possible impact from the proposed change is the loss of decay heat removal.
- However, regardless of the automatic start capability, the diesel generators must be loaded manually to the associated buses by operator action for decay heat removal in Modes 5 and 6. In addition, there is no requirement for immediate operator action for decay heat removal.
Therefore, the 3
automatic start capability of the diesel generators does not provide a safety benefit in Modes 5 and 6, and eliminating this capability will not have any adverse impact on the ability to remove decay heat or any other function during shutdown.
The proposed change will have no impact on the plant design or operation.
There will be no impact on the operability of the Safety Injection System (SIS) in Modes 1-3 when the SIS is required to be operational, or on the availability of the diesel generators when they are needed for ECCS actuation. The capability to maintain the plant in the shutdown condition for extended periods will not be degraded by the proposed change.
Therefore, the proposed change to the Technical Specification will not result in an increase in the probability of an accident previously evaluated. Since operability of the SIS or other accident mitigating systems, and the core decay heat removal capability are not adversely affected, the proposed change will not result in an increase in the consequences of an accident previously evaluated.
- 2. Will operation of the facility in accordance with this proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change will eliminate the requirement for the diesel generators to have automatic start capability in Modes 5 and 6. This change will not adversely affect the ability to remove core decay heat, or cause any new accidents. The ability of the SIS to perform its intended safety functions will not be affected by the proposed change since this system is not required to be functional in Modes 5 and 6.
Regardless of the presence of the automatic start capability, operator action is necessary in Modes 5 and 6 to load the diesel generators to their buses for decay heat removal.
In addition, SISLOP has no function in Modes 5 *and 6. Therefore, the automatic start capability is not safety significant, and provides no benefits in these modes.
The proposed change has no impact on the existing plant design, operation, safety analyses, or the ability of the plant to remain in the shutdown condition for an extended period of time. There is no impact on any factors that could create accidents. Therefore, the proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Will operation of the facility in accordance with this proposed change involve a significant reduction in margin of safety?
Response: No Elimination of the automatic start capability will not cause any delay in the removal of decay heat since operator action is required to load the diesel generators to the buses, and there is no requirement for immediate 4
operator action for decay heat removal.
The proposed change will have no impact on the existing plant design or safety analyses. Therefore, the proposed change will not involve any reduction in margin of safety.
Safety and Significant Hazards Determination Based on the above safety analysis, it is concluded that: (1) the proposed change does not constitute a significant hazards consideration as defined by 10CFR50.92; (2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change; and (3) the proposed change will not result in a condition which significantly alters the impact of the Station on the environment as described in the NRC Final Environmental Statement.
References
- 1. Letter, R. H. Engelken, NRC to L. T. Papay, SCE, April 23, 1980
- 2. Letter, Robert Dietch, SCE to H. R. Denton, NRC, "Amendment No. 92, San Onofre Nuclear Generating Station Unit 1," August 27, 1980
- 3. Letter, Walter A. Paulsen, NRC to R. Dietch, SCE, "Operability of Power Sources, San Onofre Nuclear Generating Station, Unit 1," May 3, 1983 5
ATTACHMENT 1 EXISTING TECHNICAL SPECIFICATIONS