ML19339B331

Discusses Reactor Vessel Overpressurization Potential Caused by Single Equipment Failure Per NRC 760811 Request

ML19339B331
Person / Time
Site:	Yankee Rowe
Issue date:	10/26/1976
From:	French J YANKEE ATOMIC ELECTRIC CO.
To:	Office of Nuclear Reactor Regulation
References
WYR-76-108, NUDOCS 8011060752
Download: ML19339B331 (3)

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7so.330.o733 YANKEE ATOMIC ELECTRIC COMPANY "ra 's-108 20 Turnpike Road Westborough, Massachusetts 01581

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Reference:

(1) License No. DPR-3 (Docket No. 50-29) uu (2) USNRC letter to Yankee Atomic Electric

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WW Company dated August 11, 1976 (3) Response to Reference (2), J. L. French

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requested that Yankee evaluate the potential fo Reference (2) pressurization of the reactor vessel as a result of a single equipment

{i failure, or a single operator error and to impicment design and/or procedural modifications as required to preclude such occurrences. Yankee was also requested to establish a schedule for submittal of the above information.

Reference (3) described Yankee's schedule for submittal of the requested informatien and additionally made a commitment to review its administrative controls and cperating procedures. Modifications were to be made to those administrative controls and procedures where appropriate, to minimize the possibility of a reactor vessel overpressurization occurrence.

As a result of the review effort dercribed above, the following actions have been taken at this time.

A.

Administrative Controls during all periods when the possibility of a reactor vessel overpressurization exists were reviewed in detail.

P.any precautions existed to minimize the possibility and the potential of this type of occurrence. One additional measure has been added when the reactor is in the cold shutdown mode.

During this condition, one (1) licensed operator may be assigned to the Control Room for the express purpose of monitoring the main coolant system pressure during solid water conditions.

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All plant operating procedures were reviewed in detail. This review was performed concurrent with an ongoing program which is upgrading be 8011oe o 75g

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thited States Nuclear Regulatory Commission October 26, 1976 l

Attn Office of Nuclear Reactor Regulation Page Two 4

all procedures for conformance with the new Yankee Rowe-Standard i

Technical Specifications. Many procedures already contain adequate precautions. The following procedures were modified to include further precautions and procedural steps to avoid conditions where the possibility of an overpressurization exists and minimize the potential of an occurrence.

Procedure Number Title OP-2125 Filling and Venting of the Main Coolant System OP-2105 Plant Cooldown from Hot Shutdown OP-2653 Removal of the Safety Injection System from Service j

OP-2652 Prepatation of the Safety Injection System for t

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Normal Operation OP-2002 Operations Department Personnel Shift Relief OP-2140 Periodic Jogging of the Main Coolant Pumps during an Extended Shutdown l

We trust that you will find the response satisfactory, however, should you I

desire additional information, please feel free to contact us.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY J

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REACTOR VESSEL CVERPRESSURIZATION DISTRIBUTION PER G. EEC11 10-21-76

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