ML20084R209

Forwards Analytical Justification for Treatment of Reactor Coolant Pumps During Accident Conditions, in Response to Re NUREG-0737,Item II.K.3.5 Concerning Automatic Trip of Reactor Coolant Pump

ML20084R209
Person / Time
Site:	Crane
Issue date:	05/16/1984
From:	Hukill H GENERAL PUBLIC UTILITIES CORP.
To:	Eisenhut D Office of Nuclear Reactor Regulation
Shared Package
ML20084R212	List: ML20084R209
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.05, TASK-TM 5211-84-2109, NUDOCS 8405220229
Download: ML20084R209 (2)

Text

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Route 441 South Middlotown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:

May 16,1984 5211-84-2109 Offico of Nuclear Reactor IbJulation Attn:

D. G. Eisenhut, Director Division of Licensing U. S. Nuclear IbJulatory Cannission Wasidngton, D.C. 20555

Dear Mr. Eisenhut:

Three Mile Island Nuclear Station, Unit I, (TMI-1)

Operating License No. DPR-E0 Docket No. 50-289 Autunatic Trip of Roactor 0]olant Pump (NUREG 0737 II.K.3.5)

In response to your letter of Mardt 4,1983 GPm has detennined that the tri ping of all four RC punpa ' remnmended following indication of a Small t

Break Ioss of Coolant Accideat (SEIDCA) and that it can be achieved safely and reliably by the operator (Bef.1-5). The attached report entitled " Analytical Justification for the Treatment of RC Paaps Following Ac-:ident Conditions" demmstrates that the concept of loss of subcooling nargin is an appropriate signal to alert the operator of the need to trip RC pumps and meets the intent of the critxria identified in iten II.2 of the March 4,1983 letter. Further, the analysis canbines certain best estinnte values with sana conservative assutptions to show that at least 10 minutes is available for the operator to trip the PC purps following a loss of subcooling margin.

In the event that the PC purps are not tripped in the allotted time frame, the operators are Instructed to keep the pumps running (thus ensuring adequate coro cooling).

<$g This generL cnalysis is conservative for TMI-l for the following reasons:

o EU l.

The coro power level for TMI-l is 2535 Mir wldch is lower than the 0@

analysis value of 2772 Mir. The lower steady stato power level mq results in lower decay heat power levels and less severo ccnsequences d'

following a IOCA.

N6 00 2.

'Iho HPI capacity for IMI is greater than the flow assumed in the N<

generic analysis. The acklitional injection flow provides faster 8

recovery of the core following a delayed ICP trip.

3.

1ho radial and axial power peaking assuned in the generic analysis is worso than nonnally experienced at 1MI-1. The lower peaking GPU Nuclear Corporation is a subsidiary of the Uonoral Public Utliltles Corporation

'\\

r Mr. D. G. Eisenhut, Director 5211-84-2109 Division of Licensing

3. (Con't). results in lower clad tarperatures in the hottest core channel allowing longer times for manual reactor coolant p mp trip.

With reference to section 5.4.1 of this analysis, please note that TMI-1 does not isolate RC pmp seal services except when Reactor Building pressure exceeds 30 psi or line rupture (Restart Report 2.1.1.5). Also TMI-l has implemented Abnormal Transient Procedures (ATP) which use slightly different criteria than that described in the generic B&W ATOG (see reference 5).

Sincerely, D. IIuki ctor, TMI-l IIDil/SFO/mle Enclosure cc:

J. F. Stolz J. Van Vliet R. Conte Ref:

1.

GPUN ltr dated 3/31/83 (5211-83-017) 2.

GPUN ltr dated 6/8/83 (5211-83-174) 3.

GPtN ltr dated 8/15/83 (5211-83-219) 4.

GPLN ltr dated 12/29/83 (5211-83-377) 5.

GPLN ltr dated 1/26/84 (5211-84-2015) e

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