ML19322A579
| ML19322A579 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 10/27/1979 |
| From: | Autio H YANKEE ATOMIC ELECTRIC CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| RO-50-29-79-26, NUDOCS 7911190356 | |
| Download: ML19322A579 (1) | |
Text
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N VAGEEE 1370EM9 22.207000 GGGPl]UV w
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Octcber 27, 1979 Iktited States b:le%r Reguintory Cocmission m
D Office of Inspection and Ihforcenent Vcciva I OQ 631 Park Avenue o'
"9 D
King of Prussia, Pa.
19406 m
i (JJ l
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,,v Attention: Mr. B.11. Grier Ibar Mr. Urier:
Nrsuant to the require =ents of Technical Specifications, Sectica 6.9.4,a, the following is reported as Licensee Event Report 50-29/79-26.
Prolininary co puter studies have found a potential problen vira Yankee Rwa is in a startup rode of operatico with the rain generctor separated fraa the grid.
The safety related tuses ray not be provided the ngdred voltsp,e Icvels ndi in the event of a IDCA.
' Utis probic:a results only if clo grid voltage is at the c.inire.xa enccted valte with all four min coolant pu=ps in operation.
Yankee Rrme has a three bus design concept.
There are three 2400 Volt trases, three 480 V buses md thn:e e=rgency 480 V buses.
liith the gener <
ator at power, all bus cross tie breakers are open, and the center buses s.mmt ed w the n.e m..to r.
Dn i. %
s tariup ute, ;.o. c so des center
- t r
buses is provided by cross-ties to the outer buses witich in turn are powered frca tha tu) 115 KV trans:.dssion lines.
Our cmuter stulles do not indicato my problera when the plant is in other thnn the starttp rvJe of operation.
W are in the process of confindng tlmse results, and arriving at suitable engineerJng m.lifications to alleviato i.Le situation.
In the interin, we are evaluating various procedural clanges to assure adequate voltage to the safety related buses for the forthcorting startup.
A 42 tailed report will follow in 14 days.
Very truly yours, Herbert A. Autio P. Int Superintendent IRA 7911190 3 N reg n _ _,w-
...,.