ML19207C087
| ML19207C087 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 07/20/1979 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7909060426 | |
| Download: ML19207C087 (3) | |
Text
.
_pa necm f(
o, UNITED STATES
-y * #,,
j NUCLEAR REGULATORY COMMISSION
.C WASHINGTON D. C. 70555 2
1/
JUL 2 01979 MEMORANDUM FOR:
T. Ippolito, Chief, Operating Reactors Branch #3, Division of Operating Reactors FROM:
G. Lainas, Chief, Plant Systems Branch, Division of Operating Reactors
SUBJECT:
VERMONT YANKEE, REQUEST FOR ADDITIONAL INFORMATION FOR DEGRADED GRID VOLTAGE (TAC 10059)
Plant Name: Vemont Yankee Docket No.: 50-271 Responsible Branch: ORB #3 Project Manager:
V. Rooney Reviewing Branch: Plant Systems Branch Status: Awaiting Information In response to technical assistance request TAC 10059, the Plant Systems Branch has reviewed the licensee's submittal of July 18, 1977 and found that additional infomation is required in order to complete our review.
The attached request for additional information should be forwarded to the licensee as soon as possible with a request for response within 45 days.
p.'
/
,f t v Y
's
/*
G. Lainas,' Chief Plant Systems Branch Division of Operating Reactors
Contact:
S. Rhow, X28077 J. Ibarra, LLL
Enclosure:
As stated Ulf CW 7909060 2g
/C
n a f
/
?%
2-cc w/ enclosure:
D. Eisenhut W. Gamill B Grimes V. Rooney G. Lainas D. Tondi M. Chiramal P. Shemanski S. Rhow J. Ibarra, LLL e,,.
,q e) A Lles.s C o
REQUEST FOR ADDITIONAL INFORMAi10N VERMONT YANKEE DEGRADED GRID VOLTAGE (TAC 10059)
Based on our review of your submittal dated July 18, 1977, we have concluded that your basis for not proposing a design modification to your plant electrical power distribution system undervoltagt protection is not acceptable. Your basis being that compliance with our positions, submitted to you by our letter dated June 3,1977, violates GDC-17.
We contend that without a modification your existing system may not meet the requirements of GDC-17, since GDC-17 requires that the safety functions of each of the offsite and onsite system (assuming the other system is not functioning) shall be to provide sufficient capacity and capability to assume that:
(a) specified acceptable fuel limits and the design conditions for the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences; and (b) the core is cooled and containment integrity and other vital functions are maintained during any of the postulated accidents. The offsite power system ic the common source which normally supplies power to the redundant safety related buses. Any transient or sustained degradation of this cormon source will be reflected into the safety related buses and could result in loss or damage to redundant safety loads.
In view of the above, we require that you provide your proposed design modification and changes in the Technical Specification based on the guidance contained in the staff positions submitted to you by our letter dated June 3, 1977.
e S
e