ML022800236

Technical Specification Proposed Change No.250 Scram & Isolation Valve Closure Functions of Main Steam Line Radiation Monitors Erratum to Supporting Analysis

ML022800236
Person / Time
Site:	Vermont Yankee
Issue date:	10/03/2002
From:	Balduzzi M Entergy Nuclear Northeast
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 02-80
Download: ML022800236 (3)

Text

Entergy Nuclear Northeast Entergy Nuclear Operations, Inc Vermont Yankee En i~~g}"P0 185 Old Ferry Rd Box 500 Brattleboro, VT 05302 Tel 802-257-5271 October 3, 2002 BVY 02-80 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

References:

(a) Letter, VYNPC to USNRC, "Technical Specification Proposed Change No. 250, Scram and Isolation Valve Closure Functions of the Main Steam Line Radiation Monitors," BVY 02-18, March 19, 2002 (b) Letter, USNRC to Vermont Yankee, "Vermont Yankee Nuclear Power Station - Issuance of Amendment Re: Main Steam Line Radiation Monitor (TAC No. MB4610)," September 18, 2002

Subject:

Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

Amendment No. 212 Technical Specification Proposed Change No. 250 Scram and Isolation Valve Closure Functions of the Main Steam Line Radiation Monitors Erratum to Supporting Analysis By letter dated March 19, 2002 [Reference (a)] and supplemented by letters dated June 4, July 16 and 24, August 22, and September 4, 2002, Vermont Yankee (VY) requested an amendment to Facility Operating License, DPR-28 to eliminate the reactor scram and main steam isolation valve closure requirements associated with the main steam line radiation monitors (MSLRMs) and modify other requirements related to MSLRM trip functions. The NRC subsequently granted VY's request and issued license Amendment No. 212 by Reference (b).

In support of activities to change the licensing basis, VY conducted additional analyses, revised existing analyses and updated calculations. During the process of incorporating the related changes into the Updated Final Safety Analysis Report, a review of the information provided to the NRC in Reference (a) revealed a minor discrepancy. The enclosed erratum contains a correction to Reference (a). Although the error results in less conservatism than previously stated, the impact is not significant, and consequences of postulated events remain well within acceptable limits. Accordingly, this discrepancy has no material impact on conclusions previously made by the NRC staff in this matter.

BVY 02-80 / Page 2 If you have any questions on this transmittal, please contact Mr. Gautam Sen at (802) 258-4111.

Sincerely, Michael A. Balduzzi Vice President, Operations .

STATE OF VERMONT )

)ss WINDHAM COUNTY )  ! - ,

Then personally appeared before me, Michael A. Balduzzi, who, being duly sworn, d4.lt* ;ae &at. he is :,1e President, Operations of Vermont Yankee Nuclear Power Station, that he is duly authorized eaute &-clfile thp' foregoing document, and that the statements therein are true to the best of his knowledge and be'Or. ' ,. '

Salfy A. Sandstrum, Notary Public My Commission Expires February 10, 2003 Attachment cc: USNRC Region 1 Administrator USNRC Resident Inspector - VYNPS USNRC Project Manager - VYNPS Vermont Department of Public Service

BVY 02-80 / Attachment / Page 1 of I ERRATUM TO LICENSE AMENDMENT REQUEST VERMONT YANKEE NUCLEAR POWER STATION TECHNICAL SPECIFICATION PROPOSED CHANGE NO. 250 SCRAM AND ISOLATION VALVE CLOSURE FUNCTIONS OF THE MAIN STEAM LINE RADIATION MONITORS By letter dated March 19, 2002 (BVY 02-18), Vermont Yankee proposed to amend Facility Operating License, DPR-28 by eliminating the reactor scram and main steam isolation valve closure requirements associated with the main steam line radiation monitors (MSLRMs) and modifying other requirements related to MSLRM trip functions. Attachment 1 to that letter contained a safety assessment and other information in support of the request for a license amendment. On page 13 of Attachment 1, the third bulleted paragraph stated:

The fraction of fuel melted due to the control rod drop will also add to the fission products released to the reactor coolant. NEDO-31400A assumed that 0.77% of the failed rods contained melted fuel (i.e. the equivalent of 0.0077 x 850 = 6.54 rods melted). The VYNPS UFSAR reports no fuel rod melts for VYNPS. Since the NEDO assumed that 100% of the noble gases (i.e., 10 times the release from a failed rod) and 50% of the iodines (i.e., 5 times the release from a failed rod) would be released from melted fuel, the 6.54 melted rods would be equivalent to 65.4 failed rods for the noble gases and 32.7 failed rods for the iodines. NEDO-31400A bounds the VYNPS analysis in this regard by a factor of 1.08 [i.e. (850 + 65.4) /

850] for whole body doses from noble gases, and by a factor of 1.04 [i.e. (850 +

32.7) / 850] for thyroid doses from iodines.

The last sentence of the above paragraph should be replaced with:

NEDO-31400A bounds the VYNPS analysis in this regard by a factor of 1.07 (i.e.,

[(850 x 0.9923) + (10 x 0.0077 x 850)] / 850} for whole body doses from noble gases, and by a factor of 1.03 (i.e., [(850 x 0.9923) + (5 x 0.0077 x 850)] / 850} for thyroid doses from iodines.

Thus, the resulting consequences of VY's postulated control rod drop accident are still bounded by the NRC-approved safety assessment in NEDO-31400A and remain well within acceptable limits.