ML20214R401

Responds to 870413 Request for NRR Assistance Re Whether Drywell Ventilation Tech Spec Change Necessary Following 870312 Unusual Event.Tech Spec Amend Not Necessary Due to Specs Being Silent on Ventilation Sys Design

ML20214R401
Person / Time
Site:	LaSalle
Issue date:	06/01/1987
From:	Holahan G Office of Nuclear Reactor Regulation
To:	Norelius C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8706080114
Download: ML20214R401 (2)

Text

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June 1, 1987 Docket No. 50-373 MEMORANDUM FOR: Charles E. Norelius, Director Division of Reactor Projects Region III FROM: Gary M. Holahan, Assistant Director Assistant Director for Region III and V Reactors Division of Reactor Projects - III, IV, V and Special Projects REFERENCE Memorandum from C. E. Norelius to D. M. Crutchfield dated April 13, 1987

SUBJECT:

REQUEST FOR NRR ASSISTANCE - WHETHER A DRYWELL VENTILATION SYSTEM CHANGE AT LASALLE UNIT 1 (AITS 7030011787) SHOULD REQUIRE A TECHNICAL SPECIFICATION CHANGE The following is in response to your April 13, 1987 memorandum requesting NRR assistance to determine if a Technical Specification change was necessary to accommodate a modification of the drywell ventilation system that was made following the March 12, 1987 unusual event concerning the drywell ventilation system at LaSalle Unit 1.

Section 3.6.1.7 of the Technical Specifications limits the condition for operation to a drywell average air temperature not to exceed 135*F. Since the licensee was unable to determine the average drywell temperature during the March 12, 1987 unusual event, the licensee took the conservative approach and shut the unit down. The containment system bases regarding the limitation on drywell average air temperature ensures that the containment peak air temperature does not exceed the design temperature of 340 F during LOCA conditions and is consistent with the accident analyses. The Technical Specifications for LaSalle and other BWRs in this area are the same in that they do not contain specific requirements for the operation of the drywell ventilation system. After the unusual event, the licensee modified the drywell venti;ation system from two independent systems with one fan each into one system with two fans. The NRR position is that a Technical Specification amendment was not required because the specifications are silent on the design of the ventilation system and the system has no function other than to maintain drywell temperature.

This position was discussed with-members of the Technical Specifications Branch, Division of Operational Events Assessment. While we do not believe that the licensee should have sought a Technical Specification amendment to accommodate the ventilation system design modification, this event will however be taken into consideration during future Standard Technical Specification 8706080114 870601 PDR P

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4 revisions at which time, limiting conditions for operation of ~ the drywell ventilation system may be incorporated. Should you have any questions on this issue, please contact the LaSalle Project Manager, Paul Shemanski (FTS492-8375).

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1 Original signed by/

Gary M. Holahan, Assistant Dire'ctor Assistant Director for Region III and

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