ML19323B456
| ML19323B456 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/09/1980 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8005120398 | |
| Download: ML19323B456 (2) | |
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Consumers POVrer Conspany
.1 General Ofhces. 212 West M (.higan Avenue, Jinck son, Michigan 49201. Area Code 517 7HH-0550 May 9, 1980 Director, Nuclear Reactor Regulation Att Mr Dennis M Crutchfield, Chief Operating Projects Branch No 5 U S Nuclear Regulatory Commission Washington, D C 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - RESPONSE TO NRC LETTER DATED JANUARY ll, 1980:
CONTROL ROD 3 FAILING TO FULLY INSERT NRC letter dated January ll, 1980, requested information concerning Big Rock Faint Plant's experience with control rods failing to fully insert and control rol drive malfunctions. This information was requested by April lo, 1980; how-ever, due to scheduling problems, this information is being provided at this time.
During the 1978 and 1979 period, there were only four occurrences of control rod unlatching (no other malfunctions or failures to fully insert occurred).
Three of these four occurrences were due to 22 control rod drive drifting out of the core and were on: May 6, 1978 (Deviation Report D-BRP-78 h6), May 17, 1978 (Deviation Report D-BRP-T8 hT), and July 5,1978 (Deviation Report D-BRP-78-57).
The fourth occurrence was due to E2 control rod drive drifting into the core and occurred on September 1h,1978 (Deviation Report D-BRP-78-81).
All occurrences were considered non-reportable.
Control rod drive B2 (serial number 253) was changed oitt and rebuilt.
A sticky substance was found on the surface of the piston tube, but was removed before a cample could be taken. A sample of the graphitar seals and portions of the seal-to-piston contact area were sent to Battelle Columbus Laboratories and the examination did not reveal any foreign material.
The control rod drive was cleaned, rebuilt and installed, and has not malfunctioned since.
The problem that occurred with E2 drive on September lh, 1978, was that the drive was inserting into the core. A test was performed four days later to try to duplicate the problem, but with no success.
The cause of the problem is un-l known, but the drive was changed out and inspected with no abnonnalities found.
1 Big Rock Point Plant 2
Response to NRC Letter Dated January 11, 1980 Thus, the above two, B2 and E2, drive malfunctions are not related and have not occurred since 1978.
David P Hoffban (Signed)
David P Hoffe.an Nuclear Licensing Administrator CC JGKeppler, USNRC a
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