ML19350A190
| ML19350A190 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/27/1977 |
| From: | Bixel D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-77-01, IEB-77-1, NUDOCS 8103020743 | |
| Download: ML19350A190 (1) | |
Text
(
(
[f%9 CODSumerS p'
.! Power A
Company ro T R f 5
U S
c..,. o n.c.. : m w.
o,c ~,.
4..~
s.c.,. o,c ~,., m.,.. co...u,.....o May 27, 1977 Mr James G Keppler US Huclear Regulatory Con =ission 799 Roosevelt Road Glen Ellyn, IL 60137 DOCKEI 50-155 - LICEUSE DP3 BIG ROCK POINT PLAST - RESPONSE TO IE BULLETIN 77-01 IE Bulletin 77-01 dated April 29, 1977 identified set point drift problems associated with the pneu=atic time delay relays used in control circuitry for diesel generators and requested licensee action in investigating generic problems. The purpose of this letter is to provide the resu1*s of this in-vestigation for Big Rock Point.
A complete review of the emergency diesel control circuitary was conducted to identify any set point drift proble=s. The time delay relays in the control circuitry are AGASTAT relays, not ITE Imperial. These relays are tested each refueling outage and set point drift proble=s have never been experienced.
An investigation into other plant systems using time delay relay schemes within their control circuitry was also conducted. The results of this investi ation b
indicated that no ITE Imperial relays are in use at Big Rock Point.
- Further, the only set point drift problem experienced was in the time delay relays as-sociated with the manual reactor control system.
In January 19Th the " settling time" relay in the control rod positioning circuitry experienced a complete loss of its time deJay function and was replaced.
It was also discovered that the set point of toe " insertion time" relay had drifted, and this relay was subse-quently reset.
In February 1975 the " insertion time" relay was replaced when it was found to be hangin6 up upon energizing. The set point of these and the remaining relays in this system are checked annually, and since the replacement of the aforementioned relays, no set point drift problems have been experienced.
T aed on the adequate performance of the time delay relays to date and the stringent surveillance testing program in effect at Big Rock Poirt, Consumers Pever Co=pany concludes that no further action pertinent to IE Bulletin 77-01 vill be conducted.
David A Bixel (Signed)
Da rid '. Bixel Nuclear Licensing Administrator MAY 311977 pgg3
-