ML20086G569

Proposed Tech Specs Section 3.8.3.1,Page 3/4 8-15 Re Footnote & Bases & Expansion

ML20086G569
Person / Time
Site:	Vogtle
Issue date:	07/06/1995
From:	GEORGIA POWER CO.
To:
Shared Package
ML20086G563	List: ML20086G561 ML20086G569
References
NUDOCS 9507140461
Download: ML20086G569 (2)

Text

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Revision to Proposed Footnote Addition to TS Section 3.8.3.1, page 3/4 8-15

• • The redundant emergency buses of 4160 volt switchgear 1/2AA02 and 1/2BA03 may be manually connected within the unit by tie breakers in order to allow transfer of preferred offsite power sources provided surveillance requirements of 4.8.1.1.l(a) are successfully performed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> prior to the interconnection. This interconnection will be implemented and controlled by plant procedures to assure certain preconditions and limitations are met, as described in TS Bases 3/4.8, so that the ability to simultaneously sequence both trains of LOCA loads is not adversely impacted.

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l Revised Insert to Bases 3/4.8 Electrical Power Systems Normally, the two required offsite power source circuits are connected to the onsite Class IE distribution system through their respective reserve auxiliary transformers, (RATS).

These transformers are utilized as the final point of transmission grid voltage reduction to the onsite Class IE electrical distribution system. When a RAT is unavailable, the standby auxiliary (an additional 10 CFR 50 Appendix A, GDC 17 power source) may be placed into service and connected to the onsite Class IE distribution system in order to meet the TS requirements as an OPERABLE A.C. electrical offsite power circuit.

During power operation in order to facilitate the transfer of preferred offsite power sources, independent of emergency diesel generator operation, the emergency safety busses of 4160 volt switchgear may be manually connected within the unit by tie breakers and fed from one offsite power source provided the following precautions and limitations are followed: 1) either one of the RATS, but not the SAT, may be utilized as the single offsite power source for both 4160 volt safety busses during the transfer evolution; 2) no additional nonsafety related 4160 volt loads, other than those normally fed from 4160 volt safety busses 1/2AA02 and 1/2BA03, shall be manually connected to the RAT while the busses are interconnected; 3) the automatic bus transfer schemes for the nonsafety related 4160 volt busses shall be disabled during the interconnection; and 4) the offsite power system shall have the minimum voltage necessary to assure that the offsite power source feeding both interconnected 4160 volt safety busses has the capacity and capability to simultaneously sequence both trains of LOCA loads.

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