ML19289C667

Requests Emergency Tech Spec Change to Allow Operation in de-inerted Mode Until Sufficient Supplies of Nitrogen Become Available or Sys Load Conditions Permit.Change Needed by Midnight 790121

ML19289C667
Person / Time
Site:	Quad Cities
Issue date:	01/15/1979
From:	Reed C COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 7901220083
Download: ML19289C667 (4)

Text

Commonwealth Edison 1 One First National Plata. Chicago Illinois Address Reply to: Post Office Box 767 Chicago Illinois 60690 January 15a 1973 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatorv Conniasion Washington, D.C. 20555

Subject:

Quad-citics Unit 1 Emergency Change to License DPa-2-l Appendix A, Technical specifications NRC Docket No. 50-254 Dear Sir Quad--Citico Unit 1 containmont was de-inerted at 8:15 a.m. on January 13, 1979 in preparation for a shutdown at midnight to start a normal refueling outage. It had been normal practico to de-inert and check for leaks prior to shutdown.

Later in the morning, a new weather forecast was received for Monday, January 15, 1979, changing the previous forocast of temperatures in tho 20's to -15 F in the early morning to -3 F as a high. This cold ucather forecast changed the Monday load Additionally, estimate from 10,500 megawatts to 11,100 megawatts.

at noon, our 460-mogawatt Kincaid Unit 1 was forced out of service with a tube 1eak.

These two conditions resulted in a projected 785-megawatt deficiency in meeting the Monday load without Quad--Cities Unit 1. When taking into account. racerve margins, the projected Efforts were made all day to deficiency would be 475 megawatts. ne of got corznitments for the purchase of emergency power but, late evening on January 13, our power supply office couldThis only get commitments for, 550 megawatts from other utilities.

situation created the u ,ent need to defer the Quad-cities Unit 1 outage and have the unit in operation for the Monday load.

The severe weather conditions have also caused the closing of even major highways in the area and made it extremely difficult to predict when a delivery of nitrogen can be expected.

Besides being needed to inert Unit 1, the nitrogen la also used to maintain the drywell-to-torus /]P on Units 1 and 2.

Due to pump-back system compressor malfunctions on Unit 2, the nitrogen inerting system ir; the only method available to maintain the necessary dP on that unit.

79012200Ts3

Director of Muclear Reactor Regulation January 15, 1979 Page 2 Baacd on exiating tank levoln and nitrogen usage rates for nonmal operation, the inorting of Unit 1 vould leave only 2 daya nupply of nitrogen available for normal ucc. Sinco deliveries of more nitrogen cannot be accured in this time frame, this could cauae the shutdown of both unita and a wornoning of the system load condition.

No bavo, thorofore, continued with the shutdown of Unit 1, to the point of a hot standby condition, notic fying the Tech. Spec.

requiremant to be out of the run mode within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after de-inerting.

In order to meet the load requirements fo January 15, 1979, we are requesting an emergency Tcch. Spec. change for Unit 1 to allow operation in the do-inerted mode until suf ficient supplies of nitrogen becomo availabic or system load conditione permit, but no later than midnight January 21, 1979. Encionure I indicates the proposed change to Pago 3.7/4.7-63 of the Technical Specifications.

This chango has received on-aite and off-sito revicw and approval.

Uc feel that this mathod of operation will not cause any undue hazard to the hoalth end nafety of the public for the following reasono:

1. The probability of a LOCA occurring during the period in question is extremely small.

2 Unit 1 is limited to 50% power due to const down at and-of-cycle. The lower power level makes the effects of a LOCA much less severe than those previously analyzed for full power operation.

3. Temporary emergency procedurea will be put in place to uso the inerting synkem and the standby gan treatmont system for containment dilution if a LOCA waro to occur (sbnilar to the proposed ACAD system identified in the M. S. Turbak letter to George E.

Lear dated March 28, 1978.). If Unit 1 does not inort, cufficient nitrogen should remain in the storage tar.N to allow control of containuent hydrogen levels via

" blood-and-food" operation. Additionally, containment dilution can bo performed by the use of the pump back

N Director of Nuclear Reactor Regulation January 15, 1979 Page 3 system compressor or service air which can be valved into the containment. Either of the additional air dilution systems can moet the analyzed flow rato of the ACAD system.

Pu'rsuant to 10 CFR 170, commonwealth Edison has detonained th'at the proposed amendment is clans III. Ao such, we have enclosed a foe remitance in the amount of $4,000.00.

Please direct any additional questions or comments on thic matter to this office.

Thrco (3) signed originals and thirty-ncvon (37) copics of this letter are provided for your uso.

Very truly yours, b\

Cordell Reed Annistant Vice-Procident Enclosuro SUBSCRIBED and SW 7 to hofore me thic /5- , day of I h 4 I l /19 7 / , 1979.

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(/ Notary Public L) t

l** , Q UA D-CITIES DP R-29 s.

except as specified in Specification 3.7.A.S.b.

b. Within the 24-hour period subse-quent to placing the reactor in the Run mode following a shutdown, the containment atmosphere oxy-gen concentration shall be re.

duced to less than 5% by weight, and maintained in this condition.

Deir.crting may commence 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to a shutdown.

c. For the period from 10:00 P.M.

on January 14, 1979 until midnight on January 21, 1979, the oxygen concentration limits in Paragraph 3.7.A.S.b shall not apply unless adequate supplies of nitrogen or system load con-ditions sooner allow the inerting of the containment or shutdown of the reactor

6. Containment Systems 6. Containment Systems DrywellSuppression Chamber Differential Pres- Drywell-Suppression Chamber Differential Pres-sure sure

a. Differential pressure between the drywell a. The pressure differential between the drywell and suppression chamber shall be maintained and suppression chamber shall be recorded at at equal to or greater than 1.20 psid except least once each shift.

as specified in (1),(2), and (3) below:

(1) This differential shall be established within the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period subsequent to placing the reactor mode switch C - into the RUN mode during a start-up and may be relaxed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reactor shutdown when the provisions of 3.7.A.5(b) apply.

(2) This differential may be decreased to less than 1.20 psid for a maximum of -

4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> during required operability testing of the IIPCI system pump, the RCIC system pump, the drywell-pressure suppression chamber vacuum breaker ~s, and reactor pressure relief -

vahes.

3.7/4.7-6a