ML20080A195

Advises That Util Emergency Operating Instruction Being Revised to Manually Energize Permanent Hydrogen Mitigation Sys,Due to Delay in Completion of Westinghouse Owners Group Emergency Response Guidelines

ML20080A195
Person / Time
Site:	Sequoyah
Issue date:	07/19/1983
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	Adensam E Office of Nuclear Reactor Regulation
References
RTR-NUREG-0011, RTR-NUREG-11 NUDOCS 8307250219
Download: ML20080A195 (2)

Text

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TENNESSEE VALLEY AUTHORITY

"%WtEeEfn^ tit 3f,Nre53*foEnfII July 19, 1983 Director of Nuclear Reactor Regulation Attention: Ms. E. Adensam, Chief Licensing Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Ms. Adensam:

In the Matter of ) Docket No. 50-327 Tennessee Valley Authority ) 50-328 In my September 27, 1982 letter to you we stated that the Permanent Hydrogen Mitigation System (PHMS) would be energized manually, following any accident upon the occurrence of any condition which indicates inadequate core cooling without waiting for a potential hydrogen buildup.

By my November 30, 1982 letter to you, we explained the placement of the manual operator action in the present emergency operating instructions (E0I) and in the forthcoming Westinghouse Owner's Group (WOG) emergency response guidelines (ERG). At that time we expected that the WOG ERGS would be completed soon. However, the schedule for completion of these guidelines has slipped.- We are therefore in the process of revising our current E0Is to manually energize the PHMS for both units 1 and 2 and to trip the-ice condenser air handling units (AHU) used for formal refrigeration, upon the occurrence of any condition which indicates inadequate core cooling. . Specifically, the manual operator action for energizing the PHMS and for tripping the ' ice condenser AHU was moved from the immediate actions in E0I-0 (Immediate Actions and Diagnostics) to early in EOI-1 (Loss of Reactor Coolant). We also plan to add both of the manual operation steps, for PHMS and the ice condsnser AHU, to the inadequate core cooling section of E0I-1. Placing the manual operator actions in E0I-1 will still ensure that the PHMS is energized and that the normal ice condenser AHUs are tripped before entering into an inadecuate core cooling condition that could generate hydrogen. We expect the WOG ERG's to contain similar appropriate manual. operator actions.

I Supplement 6 to NUREG-0011, page 22-3, provides a statement that the "TVA emergency operating instructions direct the operator to actuate the PHMS following any reactor trip _or_ safety injection initiation." To clarify a misconception or misunderstanding, the PHMS will be actuated following any reactor trip with safety injection initiation. This understanding has been

- previously discussed with members of your staff.

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i j 1983-TVA SOTH ANNIVERSARY L An Equal Opportunity Employer

U.S. Nuclear Regulatory Comission July 19, 1983 If you have any questions concerning this matter, please get in touch with J. E. Mills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, nager Nuclear Licensing Sworntogdsubscr ed pefore me thi /9 day of /> f # '1983 f2 Ms Notary $ublic j j My CoMaission Expires Y/[/ 8)ge t

cc: U.S. Nuclear Regulatory Comission Region II Attn: Mr. James P. O'Reilly Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 Michael H. Mobley, Director Division of Radiological Health T.E.R.R.A. Building 150 9th Avenue North Nashville, Tennessee 37203

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