ML20043H991
| ML20043H991 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 06/20/1990 |
| From: | Whittier G Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GDW-90-06, GDW-90-6, MN-90-62, NUDOCS 9006270171 | |
| Download: ML20043H991 (3) | |
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.T MaineYankee REUABLE ELECTRICITY FOR MAINE SINCE 19/7 PO. BOX 408. WISCASSET, MAINE 04578. (207) 882 6321 j
June 20, 1990 MN-90-62 GDW-90,
- l UNITED STATES NUCLEAR REGULATORY COMMISSION l
Attention:
Document Control Desk Washington, DC 20055
References:
(a)- License-No. DPR-36 (Docket No. 50-309)4 Subjec't:. Maine Yankee Control-Element Assemblies (CEA)
Gentlemen:
j The attached is in response to questions: received from Mr. Eric-Leeds of your
-staff.
Maine Yankee will' be discussing this matter further during a meeting with your staff ~on June-25, 1990.
Sincerely, f
t hh flVk G. D. Whittier, Manager Nuclear Engineering and Licensing GDW:SJJ Attachment
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'Mr. Thomas T. Martin Mr. Eric J. Leeds.
Mr. Richard J. Freudenberger.
y GDW9066.LTR 0 0 j@$62g g gggt
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ATTACHMENT NRC Ouestion:
1.
How many CEAs of the reference design are currently installed in your plant?
Provide the operating history including cycle installed and the number of operating cycles completed.
Include exposure history _ if readily available.
Response
1.
One CEA of the reference design is operating in Maine._ Yankee.
The operating history of CEAs installed in the core follows:
Number Design Cycles Used 8-New 5
5 New 3
15 New 2
15 New I
37 New 0
1 Reference 0
Exposure history will be provided separately.
NRC Ouestion:
2.
What is the' expected design lifetime for the reference design CEAs in your plant.
Resoonse:
2.
The expected design lifetime for the reference material design CEA's in Maine Yankee is at least ten years.
NRC Ouestion:-
3.
Service history infers that the strain rate versus exposure history has been underestimated in the original reference design.
What assurance can you provide-based on inspections and current exposure that all of the reference CEAs remaining in service conform to the acceptance criteria for continued operation.
Response
i 3.
There is one CEA of the reference design currently instailed 1.n the reactor..
l This CEA has not been previously used.
Experience at Maine Yankee with CEAs of the reference design indicates that this CEA will continue to perform its intended function for approximately eight cycles.
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4 ATTACHMENT Page 2 NRC Ouestion:
4.
The mechanism for the end cap failures and loss of absorber material in Maine Yankee has not been determined. What assurance can you provide that failures of this type have not occurred in your plant and will not occur during planned continuing operation with CEAs of the reference design.
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-Response:
f 4.
All CEAs installed in the plant have either not been previously used or have recently been inspected using eddy current techniques. Also, failures of this type appear to be related to the reference design and there are no CEA's of the 1
reference design installed in trippable locations, j
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1 Maine Yankee will provide additional information concerning our operating experience l
with CEA's which have been discharged to the Spent Fuel Pool'as the information i
becomes available. A meeting is scheduled with the NRC Monday, June 25, 1990 to l
discuss this matter further.
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