ML20039B783
| ML20039B783 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/15/1981 |
| From: | Hukill H METROPOLITAN EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| L1L-364, NUDOCS 8112230551 | |
| Download: ML20039B783 (4) | |
Text
I Metropolitan Edison Company Post Office Box 480 U-Middletown, Pennsylvania 17057 Writer's Direct Dial Number December 15, 1981 LlL 364 9
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G g@ [.d Office of Nuclear Reactor Regulation Attn:
D. G. Eisenhut, Director gP Division of Licensing Q
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p% #{go @d U. S. Nuclear Regulatory Commission pdf C
Washington, D.C.
20555
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Dear Sir:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Response to Appendix R to 10 CFR Part 50 As promised in our letter of March 19, 1981, LlL 077, we are providing the design criteria and schedule which will be utilized to comply with 10 CFR Part 50 Appendix R, Section III.G.
The basis for the design criteria's development and the criteria itself are described below.
The most prominent effort at TMI-l following the implementation of 10 CFR Part 50 Appendix R has been the production of a detailed " Safe Shutdown Evaluation" to supplement the TMI-l Fire Hazards Analysis (FHA). The " Safe Shutdown Evaluation" includes the identification of the systems and components required to achieve and maintain hot and cold shutdown from either the control room or. emergency control station (s) and their location wJth respect to specific fire areas or fire zones. Where it has been determined by the " Safe Shutdown Evaluation" that components of redundant safety divisions required for safe shutdown are located in the same. fire area / zone, the evaluation and the TMI-l Fire Hazards Analysis must demonstrate that:
(1) A postulated fire will not damage both safety divisions r; quired for safe shutdown, or; (2) Alternative safe shutdown capability will be provided.
Based on our review of combustible loadings for each fire area or fire zone and the equipment identified as being required to maintain hot and cold shut-down, we have prepared the following criteria for modifications to the existing arrangement in order to meet the intent of the requirements as set forth in Section III.G.1 of 10 CFR Part 50 Appendix R.
This criteria is based upon the premise that the equipment and circuits (safety kd and associated non-safety) required for safe shutdown, which are identified
/
in the " Safe Shutdown Evaluation", will not be subjected to the theoretical J
design basis fire in excess of one hour. This has been determined through the evaluation of updated combustible loading data for each fire area / zone
[
l of the plant. Where the combustible ~ loadings in a given fire area / zone, may in the-future, exceed one (1) hour, due to plant modifications, an automatic fire suppression system wil.1 be provided to supplement the planned one (1) hour barrier (s).
8112230551 811215" Mem PDR ADOCK 050002g9 er of the General Public Utsties System F
f Darr*ll G. Eisenhut LlL 364 Our specific criteria for compliance with Section III.G.1 of Appendix R is as follows:
1.
One hour fire barrier protection for a single train of safety-related cable tray located less than 20 feet apart from its redundant train when both trains are located within'the same fire area / zone.
2.
One hour fire barrier protection for a single train of safety-related tray located in the same fire area / zone as its redundant train and the trays are positioned such that an intervening combus-tible is within 20 feet of both trains.
3.
In certain cases where a single cable or small number of cables in a tray are the only circuits which must be protected in that tray' and the tray falls.under the conditions of items 1 & 2 above, these circuits may be:
a.
Removed from the tray and run in conduit near the tray-in -
which case the conduit will be protected by a one hour fire barrier, or; b.
Removed from the tray and run in conduit such that the conduit does not fall under the conditions of items 1 & 2 in which case no fire barrier will be required.
4.
Redundant components and/or equipment located within the same fire area / zone and which fall under the conditions of item 1 & 2, will be protected by partial one (1) hour fire barriers sufficient to protect the. equipment.
5.
Inside-containment, either one hour fire barrier protection or a radiant energy heat shield will be provided for a single train of cable tray or conduit which is located less than 20 feet from its redundant train.
(The radiant energy heat shield is still under investigation as a possibility for protection in lieu of one hour-fire barrier protection.)
As committed to previously, alternate shutdown capability will be provided as a means to bring the unit to a cold shutdown, independent of the equipment-in the relay roo= (cable spreading area) and the control room. The facility includes:
(1) a remote shutdown panel, and
.(2) the capability to control vital electrically operated equipment-at the power source (switchgear or motor control centers). Ihis will be acco=plished via emergency mode selector. switches which allow for the bypass of control, circuits routed through the relay or control rooms.
(see also TLL 243 dated May 30, 1980)
In addition to the protection provided via items 1-5 above automatic fire detection systems for prompt fire brigade response to a fire will be provided for all arsas presently not in compliance with Section III.G of Appendix R,
4 Darrell C. Eisenhut LlL 364 if detection systems are not already provided. Also each area will be provided with a full complement of hose stations and portable fire extinguishers if hose stations and portable extinguishers are not already provided.
It is the position of GPUN that the aforementioned criteria meets the intent of 10 CFR Part 50 Appendix R requirements for " Fire Protection of Safe' Shutdown Capability" as outlined in Section III.G.I.
GPUN requests that an exemption be granted for TMI-l as described in Attachment 1 to this letter. Appendix R Section III.J.and 111.0 are considered resolved per our letters L1L 092 (Dated 4/13/81) and L1L 142 (Dated 5/15/31) respectively.
GPUN will assemble all the data, and submit an updated IMI-l Fire Hazards Analysis by October 1, 1982. This submittal will also include the identification of non-compliances and corrective modifications for each non-compliance based upon the criteria established in this letter.
Imple-mentation of the required modifications will be consistent with manpower limitations and ALARA concerns. Based upon these considerations, GPUN intends to complete the required modifications no later than the next TMI-l Refueling Outage (Cycle 6).
Sincerely, 1
. Ht i 1 Director, TMI-1 HDH: CJS:vj f Enclosure cc:
L. Barrett J. F. Stolz R. Jacobs R. C. Haynes
ATTACHMENT 1 Exemption:
GPUN requests that an exemption be granted for TMI-l with regard to additional automatic fire suppression system protection as required by Section III.G.2 (b) &-(c) of Appendix R, where redundant safe shutdown equipment is located in' the same fire area / zone.
Safety Evaluation Jusitfying Exemption The equipment and circuits required for safe shutdown, identified in the
" Safe Shutdown Evaluation", will not be subjected to a theoretical design basis fire in excess of one hour. This fire rating is based on the combus-tible loading in each fire area / zone of the plant. Therefore, it is our position 1that the addition of automatic fire suppression systems will not enhance the ability of the plant fire protection system to maintain safe shutdown capability.
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