ML20198E975
| ML20198E975 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/07/1985 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20198E980 | List: |
| References | |
| 5211-85-2177, NUDOCS 8511140201 | |
| Download: ML20198E975 (2) | |
Text
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i GPU Nuclear Corporation
. Nuclear
- . ors
- r8o Middletown, Pennsylvania 17057-0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Nurnber:
l November 7, 1985 5211-85-2177 l
Office of Nuclear Reactor Regulation Attn: John F. Stolz, Chief Operating Reactors Branch No. 4 U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Mr. Stolz:
Three Mile Island Nuclear Station Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Fire Hazards Analysis Report and Appendix R Section III.G Safe Shutdown Evaluation Revision No. 7 The enclosed Revision No. 7 of the subject document identifies changes to GPUN's submittal of July 1,1982, letter no. 5211-82-156, as supplemented. As discussed in GPUN's letter of February 11, 1985, letter no. 5211-85-2011, it was found necessary to provide fire protection features to "B" train equipment and components rather than "A" train due to ongoing development of the detailed design of other required modifications, principally the upgraded Emergency Feedwater System (EFW) including the Heat Sink Protection System (HSPS). These modifications involve new cable routings and interfaces with safe shutdown systems throughout the plant which has necessitated a review of the 10 CFR 50, Appendix R work to assure safe shutdown capability in the event of any fire that may occur.
In many areas it was found more advantageous to provide protection of "B" train components rather than "A" train as was previously proposed. This revision also incorporates improvements in the protection schemes recognized during detailed design work completed to date.
Additionally, this revision includes protection requirements for the Reactor Coolant Pump (RCP) seals due to the concern associated with seal failure.
Although recent testing and evaluation indicates the seals will survive a loss of cooling for an extended period, no quantitative evaluation exists; therefore, GPUN has included RCP seal protection in the Appendix R evalua tion.
Furthermore, protection in conjunction with an exemption request has been proposed for the control structure ventilation system even though ongoing analysis may show that such protection is unnecessary. GPUN plans t this time to provide such protection until further resolution shows this protection is not required.
J' 8511140201 851107 pd pM.)
PDR ADOCK 05000289 F
PDR I W GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation f/
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5211-85-2177 November 7, 1985 The revised fire protection features, as discussed above, have resulted in the addition of three new fire zones and additional fire boundary modifications as described in-Section 1.3 of the. enclosed revision. The criteria used in the evaluation of fire area / zone boundaries was that agreed to by the NRC staff in a meeting with GPUN on August 14, 1984.
Although the conceptual-approach of providing fire protection features to assure the availability of one train of equipment and components for safe shutdown in the event of fire remains unchanged, protecting the "B" train results in additional protection requirements as well as changes to the exemption status. Section 3.14 provides an evaluation of the previously approved exemptions and requests additional exemptions 'for manual actions and
'the use of Rockbestos Firezone R Cable in lieu of one hour fire barriers. The conceptual use of Rockbestos Firezone R Cable, as. described in GPUN's letter of February 11, 1985, has been previously reviewed by the NRC staff and found acceptable in the NRC letter of July ~22,1985, provided that sufficient justification and. design criteria are submitted.
Section 3.14 provides a separate exenption request for each zone in which Rockbestos Firezone R Cable will be utilized.
The application fee, pursuant to 10 CFR 170.12(C), for review of the additional exemptions being requested is enclosed.
The alternative shutdown capability will remain as previously proposed and approved; however, some changes to the. design. details are anticipated as a result of those changes. described in this revision. A revised system
. description.will. be submitted at a later.date to identify these changes; however, functionally the system will remain as. described in previous submittals-so that no changes to the existing approval will be required.
This submittal revises in its entirety the July 1,1982 report and all subsequent revisions. The enclosed revision maintains the original approach of naintaining the capability to safely shutdown in the event of any postulated fire at the TMI-1 station.
Sincerely,
. D. Huk'll Director, TMI-l HDH/GB:2510f 0397A' cc: J. Thoma T. Wambach
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