ML20066G408
| ML20066G408 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 02/07/1991 |
| From: | Hannon J Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20066G412 | List: |
| References | |
| NUDOCS 9102190116 | |
| Download: ML20066G408 (5) | |
Text
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y" 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION ILLINOIS POWER COMPANY, ET AL.
CLINTON POWER _ STATION, UNIT NO.1 DOCKET NO. 50-461
_El".'IRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT s
The U. S. Nuc1 car Regulatory Commission (the Commission) is considering issuance of a temporary exemption from the requirements of Appendix J'to 10 CFR Part 50 to Illinois Power Company *, (the' licensee),
for the Clinton Power Station, Unit No.1, located in Harp Township, DeWitt C;unty, Illinois.
' ENVIRONMENTAL _ ASSESSMENT l: '
! Identification of Proposed Action The proposed action would grant a. temporary exemption from requirements contained in' Sections III.B.3 and III.C.3 of Appendix J to 10 CFR Part 50, which states, in part, that "...the combined leakage rate for all [ containment]
penetrations'and valves subject to Type B and.C tests shall be less than 0.60 i,
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The. proposed action is in accordance with the licensee's request for a temporary exemption dated January 18, 1991.
- Illinois Power Company is authorized to act as agent for Soyland Power Cooperative,.Inc. and -has exclusive responsibility and control.
over the physical construction, operation and maintenance of the l.
f acility.
9102190116 910207 I' PDR ADOCK 05000461.
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j The Need for the Proposed Action.
The; proposed exemption is needed because the requirements of Sections !!!.B.3 and III.C.3 of Appendix 0 to 10 CFR Part 50 would not be satisfactorily met if the current air leakage of feedwater containment isolation valves 1821-F032A(B) were to be included in the overall Integrated Leak Rate Test (ILRT) total.
The two feedwater containment penetrations for which this exemption is needed consist of two check valves and 'a remote-manual motor operated gate valve (gate valve) in series.
1 The situation was identified after performing extensive refurbishing on the outboard-feedwater containment isolation check valves (1821 F03kA(B)).
during the current refueling outage. Although the F032A(B) check valves passed a 1000 psig water test performed in accordance with Section XI of the ASME Code, they failed an air test pursuant to Appendix J.
In 6 discussion with the licensee on January 8,1991, the staff indicated that this penetration leakage should be calculated utilizing the check valve with the highest leakage rate. Prior to the January 8,1991. discussion, the licensee calculated the feedwater penetration leakage based on the' valve with
- the second highest' leakage.
Utilizing this methodology, the licensee took credit for the shut gate valve and assumed the valve ~with the lowest leakage failed to open. A conservative calculation of penetration leakage would: include
- the two boundaries left for containment isolation. This would result in a penetration leakage calculation equal to the leakege of the valve with the lowest individual leakage of the two remaining boundaries. The staff indicated to the licensee that the gate valves should not be counted as part of!the containment boundary, at least for the time it is open, bec6use they 4
do not respond to an automatic containrrent isolation signal.
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1 The design of the 1821-F032A(B) chect valve Ji,fers from the design of the inboard check valve (1821-F010A(B)), in that the F032A(B) check valve utilizes a tilting disc and hard seat while the F010A(B) check valve utilizes a sof t ceat design. The sof t seat design of the F010A(B) check valves makes it easier for these valves to pass the Appendix J air test. The licensee stated in its request that a permanent and effective solution (most likely involving changes to the current design) is required to censistently obtain accepte.ble air leabge results for the F032A(B) check valves. The licensee has also indicated that several months would be required to identify and evaluate the alternatives, adopt the best alternative, procure the required materials, and implement the needed changes, Based en the ab' ave discussion and the licensee's commitment to address the F032A(B) check valve air leakage problem adequately, the stuff has determined that t'lere is suf ficient need for the proposed action.
Environmental impacts of the_ Proposed Action The Comission's staff has determined that granting the proposed exemption would not significantly increase the probability or amount of expected containment leckage and that containment integrity would thus be maintained.
Consequently, the probability of accidents would not be increased, nor would the post-accident radiological releases be creater than previously determinel.
Neither vould the proposed exemption otherwise affect radiological plant effuents. Therefore, the Commission's staff concludes that there are no significant radiological i
environmental impacts associated with the proposed exenption.
t With regard to potential nonradiological impacts, the proposed
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exemption involves a change to surveillance and testing requirements.
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.o 4-j It does not affect nonradiolopical plant effluents and has no other environmental impact. Thereforn, the Commission concludes that there are no significant nonradiologit.e', environmental impacts associated with the proposed exemption.
Alternative to_the Proposed Action siice the Commission concluded that ti;erce are no significant envir+ umental impacts associated with the preposed action, any alternatives i
woL1d < tve either no or greater environmental im7,act.
The principal alte" native would be to deny the requested exemption This wc3 0 net reduce the environmental impacts attributed to the facility aut would result in a prolonged and cos(Sy extension to the current refueling outage.
Alternative Use of Resources
<G); action 'dces not' involve the use of any resources not'previously con di&Tred s 1 the " Final Environmental Statement Related to tit OperatTon of linton Power Station, Unit No.1,' deted Hay 1992.
Agencies and _?ersons Consulted The'Nhc staff reviewed the licensee's request and did nat' consult other,ogencies or persont.
' Fig [JNF OF N0;SIGNIFICANT 1MP'CT.
f/f Commission has dete 9.ined not to prepare an environmental fi-
- fmpact statu ent for the proposed exemption..
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-Based upci I.'m foregoing environmental assessment, we conclude that the proposea aytton will not have a significant effect on the quality. of the human.et,'ironr.ent.
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For further detailsifth respect tt this action, see the application for exemption dated ' January 18 -1991, which is available for public inspection'at the Commission's Public Document Room, 2120 L Street, N.W.,
Washington, D.L. 20555 and at the Vespasian Warner Public-Library,
-120 West Johnson Street, Clinton, Illinois 61727.
- Dated at Rockville, Maryland, this day of 1991.
FOR THE NUCLEAR REGULATORY COMMISSION p,= -
l Joh i N. Hannon, Director Project Directorate III-3 l'
Division of Reactor Projects'III/IV/V Office of Nuclear Reactor Regulation I
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