ML20137L984

Responds to 10CFR50.61 Requirements Re Pressurized Thermal Shock Rule to Provide Reactor Pressure Vessel Matls Assessment by 860123.Forwards Results of Assessment of Reactor Pressure Vessel Beltline Matls..

ML20137L984
Person / Time
Site:	Maine Yankee
Issue date:	01/21/1986
From:	Whittier G Maine Yankee
To:	Thadani A Office of Nuclear Reactor Regulation
Shared Package
ML20137L988	List: ML20137L984 ML20137M018
References
REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR 6958L-HFJ, GDW-86-25, MN-86-14, NUDOCS 8601280161
Download: ML20137L984 (2)

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MAME HARHEE ATOMICPOWERCOMPARUe ,uaugr,Y,,l,7,lg o",%

h (207) 623-3521 e

January 21, 1986 MN-86-14 GDW-86-25 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention: ' Mr. Ashok C. Thadani, Director PWR Project Directorate #8 Division of Licensing

References:

(a) License No. [PR-36 (Docket No. 50-309)

(b) " Policy. Issue for Pressurized Thermal Shock (PTS)",

SECY-82-465, November 23, 1982 (c) MYAPCo Letter to USNRC dated April 22, 1983 (MN-83-76)

Subject:

Response to Requirement of 10 CFR 50.61 (Pressurized Thermal Shock Rule)

Gentlemen:

This letter responds to the requirements set forth in 10 CFR 50.61(b)(1)

(Pressurized Thermal Shock Rule) to provide an assessment of Reactor Pressure Vessel Materials by January 23, 1986.

A report providing results of our assessment of Reactor Pressure Vessel o- material properties to respond to these requirements is provided in the

@ enclosure. Included are values of RTPTS for January 23, 1986 and expiration

$go$ . of License on October 21, 2008. The report also specifies the basis for g values of RTPTS as required by 10 CFR 50.61(b)(1) including those related to core loadings.

to-2d The results of this assessment demonstrate that the Pressurized Thermal .

80 Shock (PTS) screening criteria would not be exceeded until 2054 A.D. if the

$< plant were to continue operation, 46 years beyond expiration of the current l g License. The United States Nuclear Regulatory Commission Staff concluded in l

,c o Reference (b) that values of RTPTS below the screening criterion present an i m a a-acceptably low risk of vessel failure from PTS events. Therefore, PTS is not l a significant safety concern for the Maine Yankee Atomic Power Plant. 1

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6958L-HFJ I E w S a>

, e.; MAINE YANKEE ATOMIC POWER COMPANY United States Nuclear Regulatory Commission Page Two

. Attention: Mr. Ashok C. Thadani m-86-14 These conclusions are based upon continuation of the flux reduction i program committed to in Reference (c). Evidence now suggests that implementation of the flux reduction program was unnecessary to remain belcw the screening criterion at expiration of License. However, we plan to continue to use low-leakage fuel management in future cycles. We wi)' .

continue monitoring the effectiveness of these. measures and other incarmatten and update this assessment should significant changes occur in projected values.

If you have any questions, please feel free to give me a call.

.Very truly yours, MAIrE YANKEE ATOMIC POWER COWANY Jb 0 / 1 G. D. Whittier, Manager Nuclear Engineering & Licensing GDW/bjp

Enclosure:

cc: Dr. Thomas E. Murley Mr. Cornelius F. Holden f

6958L-HFJ

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