NRC Generic Letter 1981-24
| ML031210452 | |
| Person / Time | |
|---|---|
| Issue date: | 06/15/1981 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| GL-81-024, NUDOCS 8107310298 | |
| Download: ML031210452 (2) | |
tA REG(,, k UNITED STATES
- NUCLEAR REGULATORY COMMISSION
< £i WASHINGTON, D. C. 20555 June 15, 1981 LICENSEES OF ALL GE BWR FACILITIES (EXCEPT HUMBOLDT BAY)
SUBJECT: MULTI-PLANT ISSUE B-56, CONTROL RODS FAIL TO FULLY INSERT
(Generic Letter No. 81-24)
Gentlemen:
By letters dated August 29, 1978 and January 10, 1980, you were requested to provide information on your experience with one or more control rods stopping short of the fully inserted position on scram and then settling back to notch position "02" or six inches short of full insertion.
We have evaluated your responses, along with those provided by other BWR
licensees, and have concluded that the problem of control rods inserting only to notch position "102" on scram is attributable to leakage past worn I stop and drive piston seals. We have determined that this problem is a maintenance problem, and is readily correctable by control rod drive over- haul at a subsequent outage. We have further concluded that Technical Specification requirements regarding control rod operability and shutdown margin provide adequate assurance of the capability to place and maintain the plant in a safe shutdown condition. Consequently, the failure to fully insert events, as described herein, do not represent a significant safety issue.
The enclosed safety evaluation provides the basis for this determination.
Sincerely,
/ Darrell G. Eisenhut, rector Division of Licensing Office of Nuclear Reactor Regulation Enclosure:
Safety Evaluation cc w/encl:
Service List
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yw BOILING WATER REACTOR LICENSEES
Docket No. 50-293 Docket No. 50-245 Pilgrim Unit 1 Millstone Unit 1 Docket No. 50-325 Docket No. 50-263 Brunswick Unit 1 / Monticello Docket No. 50-324 - .9 04 9 Brunswick Unit 2 Docket No. 50-10 . Docket No. 50-277 Dresden 1 Peach Bottom Unit 2 Docket No. 50-237 Docket No. 50-278 Dresden 2 Peach Bottom Unit 3 Docket No. 50-249 Docket No. 50-333 Dresden 3 FitzPatrick Docket No. 50-254 Docket No. 50-259 Quad-Cities Unit 1 Browns Ferry Unit 1 Docket No. 50-265 Docket No. 50-260
Quad-Cities Unit 2 Browns Ferry Unit 2 Docket No. 50-155 Docket No. 50-296 Big Rock Point Browns Ferry Unit 3 Docket No. 50-409 Docket No. 50-271 Lacrosse Swcj. Vermont Yankee Docket No. 50-321 Edwin I. Hatch Unit 1 I
Docket No. 50-366 Edwin I. Hatch Unit 2 Docket No. 50-331 Duane Arnold Docket No. 50-219 Oyster Creek Docket No. 50-220
Nine Mile Point Unit 1 Docket No. 50-298 Cooper Station