ML19261B257
| ML19261B257 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 01/30/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19261B256 | List: |
| References | |
| NUDOCS 7902150132 | |
| Download: ML19261B257 (3) | |
Text
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ATTACHMENT TO LICENSE AMENDMENT NO. 49 FACILITY OPERATING LICENSE N0. DPR-29 DOCKET N0. 50-254 Replace pages 3.7/4.7-6a and 3.7/4.7-7 of the Appendix "A" Technical Specifications with the enclosed pages.
7902150(3 }
QUAD-CITIES DPR-29 except as specified in Specification 3.7.A.5.b.
b.
Within the 24-hour period subse-quent to placing the reactor in the Run mode following a shutdown, the containment atmosphere oxygen concentration shall be reduced to less than 5% by weight, and main-tained in this condition.
Deinerting 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 pericd from 10 P.M.
January 14, 1979 to midnight January 21, 1979, the oxygen concentration limit in para-graph 3.7. A.5.b shall not apply unless adequate supplies of nitrogen or system load condi-tions sooner allow the inerting of the containment or shutdown of the reactor.
6.
Containment Systemi 6.
Containment Systems Drywell-Suppression Chamber
.Drywell-Suppression Chamber Differential Pressure Differential Pressure The pressure differ-a.
a.
Differential pressure ential between the between the drywell and drywell and suppressier.
suppression chamber shall chamber shall be recorded be maintained at equal to at least once each shift.
or greater than 1.20 psid except 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 into the RUN mode during a startup 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.
3.7/4.7-6a Amendaent No. 49
QUAD-CITIES DPR-29 (2) T11s 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 HPCI system pump, the RCIC system pump, the drywell-pressure suppres-sion chamber vacuum breakers, and reactor pressure relief valves.
(3)
If the Specifications of 3.7.A cannot be met, and the differen-tial pressure cannot be restored within the subsequent six (6) hour period, an )rderly shut-down shall be initiated and the reactor shall be in a cold shutdown condition in the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
B.
Standby Gas Treotment System B.
Standby Gas Treatment System 1.
Two separate and independent standby 1.
At least once per month, initiate gas treatment system circuits shall be frem the control room 4000 cfm operable at all times when secondary
(+ 10%) flow through both circuits containment integrity is required, oT the standby gas treatment system except as specified in sections for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> with the 3.7.B.l.(a) and (b).
circuit heaters operating at rated power.
a.
After one of the standby gas a.
Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> from the time treatment system circuits is made that one standby gas treatment or found to be inoperable for any system circuit is made or found reason, reactor operation and fuel to be inoperable for any reason handling is permissible only during and daily thereafter for the the succeeding seven days, provided next succeeding seven days, that all active components in the initiate from the control room other standby gas treatment system 4000 cfm (+ 10%) flow through shall be demonstrated to be oper-the operable circuit of the able within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and daily standby gas treatment system thereafter. Within 36 hourt follow-for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> with the ing the 7 days, the reactor shall be circuit heaters operating.
placed in a condition for which the standby gas treatment system is not required in accordance with Spec-ification 3.7.C.l.(a) through (d).
[
b.
If both standby gas treatment system circuits are not operable,
=
within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> the reactor shall be placed in a condition for which
[
the standby gas treatment system 6
is not required in accordance with Specification 3.7.C.l.(a) 3 through (d).
3.7/4.7-7
[oRec n
o UNITED STATES NUCLEAR REGULATORY COWAISSION y}
- g WASHINGTON, D. C. 20656 N
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,e SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION AMENDMENT NO. 49 TO LICENSE NO. DPR-29 QUAD CI'IES NUCLEAR POWER STATION UNIT NO. 1 COMMONWEALTH ElISON COMPANY AND IOWA-ILLIN0IS GAS AND ELECTRIC COMPANY DOCKET N0. 50-254 Introduction 14, 1979, the Comonwealth Edison Company (CECO)
By telecopy on January requested an amendment to the operating license of Quad Cities Unit No.1 that would extend the period required to establish an inerted atmosphere in the containment beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The extension is requested from 10 P.M. January 14, 1979 to a time no later than midnight January 21, 1979.
Discussion Quad Cities Unit I containment was deinerted at 8:15 A.M. on January 13, 1979 in preparation for a normal shutdown for refueling.
Later in the morning of January 13, a new weather forecast was received for Monday, January 15 which indicated a probable need for the generating capacity of Quad Cities Unit 1 if the system load demands were to be met on January 15.
Later in the day, an additionai 450 MW capacity was lost to the system when another station was forced out of service due to mal-function. The conditions resulted in a projected 785 MW deficiency in meeting the January 15 load without Quad Cities Unit No. I with no reserve margin.
Efforts were made at that time to purchase emergency By the evening of January 13, comitments could be had for only power.
The 550 MW from neighboring utilities, again with no reserve margin.
situation then became one of urgent need to defer the Quad Cities outage and have the Unit in operation for the Monday January 15, load.
There is not presently available onsite sufficient nitragen to reinert the containment and, because of severe weather conditions, there is little chance of obtaining the nitrogen by Monday, January 15.
In order to meet the load requirements for January 15, 1979 and possible succeeding days, CECO requested a change in their Technical Specifications that will allow them to operate, on a provisional basis, with the containment deinerted, for up to about a week.
Evaluation During normal plant operation, the primary contair. ment of Quad Citics Unit No. 1 is inerted (i.e., the oxygen concentration is maintained at less 790215064M
. than 5% by weight) as part of the measures to control potential combust-ible gas concentrations within the primary containment following a postu-lated loss-of-coolant accident (LOCA).
Specifically, tne requirement for inerting resulted from the assumption of a reaction of 5% of the fuel zircaloy cladding with the primary system coolant as specified in Safety Guide 7 (presently referred to as Regulatory Guide 1.7).
This amount of
" metal-water" reaction will lead to combustible gas concentrations within a very short period of time following a LOCA.
The Technical Specification requirements for Quad Cities currently allow a 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 in the "RUN" mode for the inerted condition to be estu.;ished. This allowance is based on consideration of the low probability of a LOCA event within this limited period of time, the reduced consequences at lower power levels, and the level of difficulty associated with establishing and maintaining an inerted condition during the atmospheric transients that occur within the containment during startup.
The licensee has requested an extension of this 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period to estab-lish an inerted atmosphere within the containment. This request resulted from severe local weather conditions which have caused the licensee to defer a scheduled refueling outage for about one week. There presently is not a sufficient supply of nitrogen available at the plant site to establish and maintain an inerted containment atmosphere in both units for a period of time sufficient to obtain additional nitrogen.
In early 1975, the licensee submitted a proposed combustible gas control system design that would not require inerting. This system design was predicated on a lower metal-water reaction which was being considered as part of a proposed change to the Connission's regulations. A new rule (i.e., 10 CFR 50.44), which became effective on November 27, 1978, would allow the assumed metal-water reaction to be based on the results of the Emergency Core Cooling System analyses requirements of 10 CFR 50.46.
Although the staff has not completed its review of the proposed system design, the preliminary analyses indicate that inerting would not be required for Quad Cities under the provisions of the new rule, and that an air-dilution system would be an effective means of manually controlling combustible gas concentrations following a LOCA.
Based on these analyses, we conclude that combustible gas control measures could be provided by means other than inerting.
In conjunction with the proposed change to the plant Technical Specifica-tions, the licensee will alsc implement emergency procedures which direct the plant operators to take alternate actions in the event of a LOCA with the plant deinerted.
In addition, because of end of cycle reactivity considerations, Unit No.1 will be operated below about 50% of licensed powar.
The alternate conbustible gas control is designed to provide dilution and purging of the containment atmosphere. At the present time, this system is not operational nor are the associated atmosphere monitoring subsystems available. However, the licensee has determined that air dilution and purging can be provided by existing systems at rates equal to or greater than that specified for the proposed system. Further, the emergency procedures call for durations of dilution and purging based on the system design analyses, since the atmosphere monitoring subsystems are not operational.
Based on our preliminary assessment of the proposed system design, we conclude that the licensee's emergency procedures are sufficient to assure combustible gas control following a postulated LOCA and to assure that offsite exposures are acceptable.
On this basis, we conclude that this action is acceptable for the period proposed.
Sunnary Based on the licensee's power needs, the low probability of a LOCA event within the limited period of time associated with this action, the emergency procedures instituted by the licensee, and the reduced power level of the plant, we conclude that Quad Cities Unit No. I can operate safely with a deinerted containment for the proposed period of about one week and still provide adequate measures for combustible gas control should a LOCA occur.
Environmental Consideration We have determined that !.he amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and pursuant to CFR 51.5(d)(4), that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of the amendment.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reason-able assurance that the health and safety of the public will not be en-dangered by oneration in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment. will not be inimical to the cocuon defense and security or to the health and safety of the public.
Dated:
January 30, 1979