ML20043H111
| ML20043H111 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 06/08/1990 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | PORTLAND GENERAL ELECTRIC CO. |
| Shared Package | |
| ML20043H110 | List: |
| References | |
| NUDOCS 9006220021 | |
| Download: ML20043H111 (7) | |
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION l
1 In the Matter of PORTLAND GENERAL ELECTRIC COMPANY Docket No. STN 50-344 l
(Trojan Nuclear Plant, Unit 1) l EXEMPTION j
1.
By letter dated April 18, 1990, the Portland General Electric Company (PGE,thelicensee),ownerandoperatoroftheTrojanNuclearPlant, requested an exemption from certain requirements of 10 CFR Part 50, Appendix J, regarding testing of containment airlock door equalizing valves.
Trojan is a pressurized water reactor located in Columbia County, Oregon, on the Columbia River.
Appendix J of 10 CFR Part 50 requires the licensee to perform primary contain-l ment. leakage testing, 11.
Appendix J of 10 CFR Part 50, requires that testing of containment airlock equalizing valves be included in the airlock leakage tests as addressed in TrojanTechnicalSpecification(TTS)3.6.1.3,"ContainmentAirLocks."
Because of its design, however, the equalizing valves on the inner door of
- each airlock cannot be tested in the manner required by Appendix J.
- PGE, therefore, requested an exemption from a requirement of Appendix J fot that
-valve, and proposed an alternative test method to demonstrate the inf.egrity of the seals for that valve. The proposed test would utilize the exist.ing l
90062200219joO 44 PDR ADOCK O pg P
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reduced pressure test port to test the leak-tightness of the o-ring seals of the equalizing valve. Any leakage (rate) would be multiplied by the ratio of L
the airlock barrel pressure and the test pressure, and added to the airlock barrel leakage rate.
This type of test is necessary and appropriate for several reasons.
It is a reasonable method for testing the integrity of the 0-ring seals, and quantifying any leakage as a contribution to the total leak rate of the airlock at design pressure Pa (60 psi). The test performed in this manner gives a measure of the leakage in the seals at design pressure despite the fact that the valve, designed to protect against a design LOCA pressure in the oppositedirection(i.e.frominsidethecontainment),cannotwithstand(by design) a pressure of 60 psi in the opposite direction (i.e. from the airlock sideofthevalve). The test, while not conforming to the Appendix J requirement for Type B testing of the airlock seals, is the best possible approximation, and involves the minimum deviation from the prescribed Appendix J Type B test consistent with the limits imposed by equipment design.
The proposed exemption to the testing requirement of 10 CFR Part 50,
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Appendix J, for the containment airlock door equalizing valve, and the proposed alternative testing methods, have been considered by the NRC staff.
For t
reasons set forth above, the staff finds the requested exemption acceptable.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12 (a)(1),thisexemptionisauthorizedbylaw,willnotpresentanundueriskto the public health and safety, and is consistent with the common defense and security. The Commission further determines that special circumstances, as provided in 10 CFR 50.12(a)(2)(ii), are present to justify the exemption,
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In the circumstances of this case application of the regulation would not serve the underlying purpose of the rule. Because of the design limits of the equipment, the tests cannot be performed as required by the regulation. The tests to be performed as proposed satisfy the underlying purpose of the l
requirement, to measure the leak rate of the airlock as part of the overall measurement of the leak tightness of the containment.
III.
Accordingly, the Comt.. ion hereby grants an exemption as described in Section 11 above from compliance with the requirements of Appendix J, of 10 CFR Part50,SectionIll.D.2.b(1).
The licensee may perform the proposed test 1
of the inner airlock door as described as an alternative to fulfilling the testing requirements of 10 CFR Part 50, Appendix J Section III.D.2.b(1) for
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the inner airlock door equalizing valves.
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i Pursuant to 10 CFR 51.32, the Commission has determined that the granting i
of this exemption will have no significant impact on the quality of the human environment (June 5,1990,55FR22975).
l This exemption is effective upon issuance, i
FOR THE NUCLEAR REGULATORY COMMISSION 42r/. Nd Ao 1
Ififecto Dennis M. Crutch Division of Reactor Pro Wcts Ill, l
IV, Y and Special Projects Office of Nuclear Reactor Regulation Dated at Rockville, Maryland this 8th day of June 1990.
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_ UNITED STATES NUCLEAR REGULATORY COMMISSION f
PORTLAND GENERAL ELECTRIC COMPANY l
THE CITY OF EUGENE. OREGON i
DOCKET NO. 50-344 TROJAN NUCLEAR PLANT t
ENVIRONMENTAL ASSESSMENT AND FINDING OF NO $1GNIFICANT IMPACT The U.S. Nuclear Regulatory Comission (the Comission) is considering l
1ssuance of an exemption from the requirements of 10 CFR Part 50 Appendix J.
Section III.D.2.b(1) for the containment airlock door equalizing valves of the Trojan Nuclear Plant. The Portland General Electric Company (PGE, the licensee)isthelicenseefortheTrojanPlant,locatedinColumbiaCounty, Oregon.
ENVIRONMENTAL ASSESSMENT Identification of Proposed Action:
The proposed action would grant an exemption from the requirements to perform containment leak testing for 10 CFR Part 50, Appendix J, Section Ill.D.2.b(i)forthecontainmentairlockinnerdoorequalizingvalves. By letter dated April 18, 1990, the licensee requested an exemption from the requirements of 10 CFR Part 50, Appendix J Section !!!.D.2.b(1) for the containment airlock inner door equalizing valves.
The Need for the Proposed Action:
The requirements of 10 CFR Part 50, Appendix J. Section !!!.D.2.b(1) make-no provision for alternative methodology for testing airlocks at an interval pressure of less than Pa, as defined in Appendix J.
However, all parts of the i.
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2 equipment, notably the inboard door equalizing valves, cannot be tested at pressure Pa in the airlock because it is designed (properly) to withstand pressure Pa in the opposite direction, which is the direction in which the design basis accident exerts design basis accident force on the valve.
Accordingly, the licensee has requested an exemption from that part of 10 CFR Part 50, Appendix J which requires airlock testing of the containment 41rlock inner door equalizer valve at a pressure not less than Pa, since the v61ve is notdesigned(norwoulditbecalledoninadesignbasisaccident)to withstand a pressure of Pa in the direction associated with airlock testing.
Since the valve cannot, by design, withstand the required pressure of Pa in the f
required airlock test, the licensee has a need for an exemption from a testing requirement that cannot by design meet the regulatory requirement.
Environmental Impact of the proposed Action:
The proposed exemption affects only the method by which the equalizer valves in the containment airlock inner doors are tested to determine the rate of seal leakage associated with the valves. The proposed action does not affect the risk of facility accidents and could not reasonably have any significant environmental impact. The post-accident radiological releases will not differ from those determined previously, and the proposed exemptia does not otherwise affect facility radiological effluents, or any significant occupational exposures. With regard to potential non-radiological effluents, the proposed exemption does not affect plant non-radiological effluents and has no other adverse environmental impact. Therefore, the Comission concludes there are no measurable radiological or non-radiological environmental impacts associated with the proposed exemption.
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4 Alternative to the Proposed Action:
Since we have concluded there are no significant environmental impacts for the proposed actions, any alternatives with equal or greater environmental impacts need not be evaluated.
The principal alternative would be to deny the requested exemption. Such an action would not reduce environmental impacts of the plant operatior.
Alternative Use of Resources:
This action does not involve the use of resources not considered previously in the Final Environmental Statement for the Trojan Nuclear Plant.
Agencies and Persons Consulted:
The NRC staff reviewed the licensee's request and did not consult other agencies or persons.
FINDING 0F NO SIGNIFICANT IMPACT:
The Commission has determined not to prepare an environmental impact statement for the proposed exemption.
Based upon the environmental assessment, the NRC staff concludes that the proposed action will not have a significant effect on the quality of the human environment, i
For details with respect to this action, see the licensee's submittal dated April 18, 1990, which is available for public inspection at the Commission's Public Document Room, Gelman Building, 2120 L Street, N.W.,
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4-Washington, D.C. and at the local public document room for the Trojan Nuclear-Plant at the Branford P. Millar Library: Portland State University Portland, Oregon 97207.
Dated at Rockville, Maryland, this 31 day of May 1990.
FOR THE NUCLEAR REGULATORY COMMIS$10N
..,4 John T. Larkins, Acting Director Project Directorate V Division of Reactor Project - !!!,
IV, Y and Special Projects Office of Nuclear Reactor Regulation I
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