ML20235N438
| ML20235N438 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 09/30/1987 |
| From: | Whittier G Maine Yankee |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 9179L-SDE, GDW-87-230, MN-87-108, NUDOCS 8710060519 | |
| Download: ML20235N438 (2) | |
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MaineYankee REUABLE ELECTRICITY FOR MAINE $1NCE 1972 EDISON DRIVE. AUGUSTA, MAINE 04330.(207) 622-4868 September 30, 1987 MN-87-108 GDH-87-230 United States Nuclear Regulatory Commission Attention:
Document Control Desk Hashington, D. C.
20555
References:
(a) License No. DPR-36 (Docket No. 50-309)
(b) MYAPCo Letter to USNRC dated November 10, 1986 (MN-86-141)
(c) USNRC Letter to MYAPCo dated January 6, 1987 - Safety Evaluation of Large Break ECCS Evaluation Model Phase I.
(d) HYAPCo Letter to USNRC dated May 21, 1987 (MN-87-59) l
Subject:
Review of Revised LOCA Methodology - Steam Cooling Model l
Gentlemen:
In Reference (b), and in our October 22, 1986 meeting with NRC representatives, Maine Yankee proposed a two-phase program to revise the LOCA methodology for Maine Yankee. The intent of the program is to regain lost margin to LOCA limits and ensure adequate LOCA limit margins for future cycles.
The NRC has approved Phase I - implementation of an improved delta p injection penalty for the reflood phase of the ECCS evaluation - in Reference (c).
Phase II of our program - implementation of a revised steam cooling model was described in detail during our meeting with the NRC on December 16, 1986 and submitted for NRC review and approval in Reference (d).
Based upon our assessment of the current fuel performance characteristics, the higher peaking factors expected during Cycle 11 could limit plant operation if the revised steam cooling model is not implemented as we had anticipated. Hithout the application of this revised model, Maine Yankee could face a potential future derate in power operation.
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United States Nuclear Regulatory Commission Page Two Attention:
Document Control Desk MN-87-108 Accordingly, we request your review and approval of our proposed model,
- Reference (d).for use in the design and analysis of Cycle 11. He anticipate that NRC approval of the revised model will be necessary by the'end of 1987 to
- provide adequate time for implementation.
He would be happy to discuss this issue-further with your staff if necessary.
'Please contact us if you have any further questions.
Very truly yours, MAINE YANKEE
(
AJ $ /L v G. D. Whittier, Manager Nuclear Engineering and Licensing GDH/bjp cc: Mr. Victor Nerses Mr. H1111am T. Russell Mr. Pat Sears Mr. Cornelius F. Holden i
9179L-SDE j
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