ML20236K774

Proposes Interim Operation Plan to Use Svc Bldg Chiller Sys While Completing Retubing Activities of Control Room Ventilation Sys Chillers.Crosstie Would Link Svc Bldg & Control Room Chilled Water Sys as Noted in Util

ML20236K774
Person / Time
Site:	Braidwood
Issue date:	10/30/1987
From:	Hunsader S COMMONWEALTH EDISON CO.
To:	Murley T NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), Office of Nuclear Reactor Regulation
References
3776K, NUDOCS 8711090352
Download: ML20236K774 (2)

Text

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,' Chicago, Illinois 60690 0767 October 30, 1987 Mr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 Attn: Document Control Desk

Subject:

Braidwood Station Units 1 and 2 Control Room Ventilation (VC)

Interim Operation plan NRC Docket Nos. 50-456 and 50-457 References (a): September 9, 1986 A.D. Miosi letter to H.R. Denton (b): NUREG-1002, Safety Evaluation Report, Supplement #2, dated October, 1986 (c): March 26, 1987 S.C. Hunsader letter to H.R. Denton (d): NUREG-1002, Safety Evaluation Report, Supplement #4, dated July, 1987

Dear Mr. Murley:

Reference (a) provided Commonwealth Edison's. interim operation plan for the control room ventilation (VC) system. Section 6.5.1 of reference (b) provided the staff evaluation and acceptance of that plan. This acceptance included the provision, during fuel loading and reactor system testing before initial criticality, that one train of the VC emergency make-up filter system be available including an associated chiller system and control room air handling unit. Reference (c) provided our plan to utilize on a temporary basis in the early summer of 1987, the service building chilled water system in lieu of the control room chiller. Section 6.4 of Reference (d) provided the NRC evaluation and acceptance of this plan. This evaluation concluded that the proposed cross-tie to the service building chiller system would meet General Design Criterion (GDC) 4 of Appendix A to 10 CPR 50 as described in Standard Review Plan Section 9.4.1 of NUREG-0800 and would, therefore, be at; acceptable means for providing adequate temporary cooling to the control room envelope.

The purpose of this letter is te provide our plan to again utilize the service building chiller system.

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chilleri,}InaneffhttocontjutetheretubingactivitiesoftheVCSystem prior t(ilnitial criticality of Braidwood Unit 2, a temporary crosstie of the service buildirig and control room chilled water systems is 3

This 'rosstie will again add the load of the again being consi'dored.

c contreal room cooling to the service building chilled water system. This method has utilized early in the summers of 1986 and 1987 during the control 3

room 5. W ec watar system construction. completion and preoperational tett;5nd end proved more than adequdte in maintaining control room / auxiliary e

elec.'tric dkr tet)eratures at desis values during the specified period in i

the strame'r. h s

h As tad teen presente 'in referer.ce (c), two temporary pipe t

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i sectins, 'an#!wpply and one return, will be re-connected to provide a ficQath from 'tde service building chilled water header piping, (near the

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radia(ion chetL7try igboratory ' air handling unit) to the control room i

coolins coils),111 equipment 'in the control room chilled water system, other than the'd.Uling' coils an'd their associated supply and return water

[T pipidg;s'will be Llolated frca the service building chilled water system.

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UtMziUg the service buildinQ chillers, and the chilled water pumps and

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t.ipiab, an adequate source 1oC 42*F chilled water will again be provided to all control room ventilation loads. We anticipate this configuration co@'o in place for approximately 45. days and should be more than adequate to tc'b

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supply cooling durine the winter.

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The proposed configuration is the same as that which was presented in reference (c) and accepted in reference (d).

The evaluated finding of safety significance will not be changed since Braidwood Unit 1 will be in cold shutdown (mode 5}'and Unit 2 is expected to be in a condition no more than its pre-critical testing phase.

No changes are necessary to the Braidwood Technical Specifications.

Technical Specification 3/4.7.6 currently includes a note that rendered it s not applicable until Braidwood Unit 1 initial criticality. Commonwealth 611 son requests that this note remain in place for Braidwood Unit 2 so that j

bhit 2 pre-critical testing can proceed during the anticipated Unit 1 outage and the concurrent chiller retubing woth.

Braidwood Unit 1 will be maintained in cold shutdown during the chfLler retubing effort. No positive reactivity changes or core alterations A:

will be ser @ ted.

As such, we will maintain compliance with the I appropri dhionstatementrequirementsofTechnicalSpecification3.7.6.

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2 nd is bains submitted for NRC review and acceptance. Please address ariy huestions concerning this matter to this office.

f' Very truly yours, i

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Jcf S. C. Hunsader

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Nuclear Licensing Administrator g'

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