ML20086L850
| ML20086L850 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 01/17/1984 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT |
| Shared Package | |
| ML20086L854 | List: |
| References | |
| NUDOCS 8402140536 | |
| Download: ML20086L850 (6) | |
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7590-01 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMf11SSION In the Matter of
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Docket No. 50-331
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IOWA ELECTRIC LIGHT AND POWER
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COMPANY
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(Duane Arnold Energy Center)
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EXEMPTION I.
The Iowa Electric Light and Power Company (IELP/the licensee) is the holder of Facility Operating License No. DPR-49 (the license) which authorizes operation of the Duane Arnold Energy Center (DAEC) located in Linn County, Iowa, at steady state reactor core power leyels not in excess of 1658 megawatts thermal.
This license provides, among other things, that it is subject to -
all rules, regulations and Orders of the Commission now or hereafter in effect.
II.
Section 50.54(o) of 10 CFR Part 50 requires that primary reactor con-tainments for water cooled power reactors be subject to the requirements of Appendix J to 10 CFR Part 50. Appendix J contains the leakane test require-ments, schedules, and acceptance criteria for tests of the leak-tight in-tegrity of the primary reactor containment and systems and components which 4
penetrate the containment. Appendix'J was published on February 14, 1973 and in August 1975, each licensee was requested'to review the extent to which its facility met the requirements.
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PDR ADOCK 05
r<. On August 7, 1975, IELP submitted its evaluation of the DAEC in which it assessed compliance with the rule and also requested an exemption from certain requirements of the rule. The IELP submittal for the DAEC was supplemented by letter dated Augus't 29, 1978 and November 5, 1981 and clarified in a telephone discussion on October 1, 1982.
In these submittals, IELP requested that certain test methodology, components, and penetrations be exempted from Appendix J reouirements.
The Franklin Research Center, as 1
a consultant to NRR, has reviewed the licensee's submittals ard prepared a l
l Technical Evaluation Report (TER) dated March 17, 1982. The NRC staff has reviewed this TER, and in its Safety Evaluation dated April 2, 1982, concur-red in the TER's bases and findings.
However, for Item 2 below, pertaining to airlock door testing, the staff performed an additional evaluation prior to determining the acceptability of the licensee's request.
1.
Section III.C.2 of Appendix J requires, in part, that Type C testing be performed at the peak calculated accident pressure (Pa).
IELP reauested an exemption from this. requirement for the Main Steam Isolation Valves (MSIVs) to permit testing at 24 psig rather than at Pa (48 psig) and submitted certain design information as justification.
The MSIVs are leak tested by pressurizing between the valves.
The MSIVs are angled in the main steam lines in the direction of flow in order to afford better sealing upon closure. A test pressure of Pa acting under the inboard disc is sufficient to lift the disc off its seats, and results in excessive leakage into the reactor vessel. This would result
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' in a meaningless test. The proposed test calls for a test pressure of 24 psig to avoid lifting the disc at the inboard valve. The total obse.rved leakage through both valves (inboard and outboard) is then conservatively assigned to the penetration. On this basis, we conclude that testino at a reduced pressure of 24 psig is acceptable.
2.
In a letter dated November 5, 1981, IELP reauested an exemption from the airlock door testing requirements of Section III.D.2(b), which was revised effective October 2?, 19Ph.
The revised rule required testing of the airlocks as follows:
a.
Every six nonths at a pressure of not less than Pa (and after periods when the airlock is opened and contairment integrity is not reouired).
b.
Within three days of opening for every three days durina periods of frecuent openino) when containment integrity is required, at a pressure of Pa or at a reduced pressure as stated in the Technical Specifications.
Our consultant, the Franklin Research Center (FRC), has reviewed the licensee's proposal to (1) test contairment airlocks at a pressure of Pa and at an interval not longer than one operating cycle, and (2) whenever the airlock was opened during the operating cycle, and-containment integrity 4
was required, the airlock gasket would he tested at Pa followino closure if it had been greater than 3 days since.the last leakage test.
FRC concluded that the licensee's proposal to test airlock gaskets within 3 days of an airlock opening is acceptable. However, FRC did not fi_nd acceptable the licensee's proposal to test-the entire airlock at a pressure of Pa once per operating cycle, since it.did not make adequate allowances to
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4-detect potential deterioration of airlocks through normal use, to detect possible damage to the door mechanism, to detect potential damage to door seals through moving equipment-into and out of containment, and to detect possible fouling of seals during closure.
FRC proposed that testing of the entire airlock assembly at a pressure of Pa should be conducted at the six-month interval as required by Appendix J.
We agree with the FRC's conclusion that the airlock gasket leakage be tested w4 thin 3 days from an cirlock openino.
We further agree with the FRC's conclusion that the airlock testing frequency should make adequate allowances to detect potential deterioration of airlocks through normal use.
However, when the airlock remains closed, that is, there is no opening or closing of the doors to cause degradation of seals or damage to door mdchanisms, we find that. the reduced pressure testing frequency proposed by the licensee would be adequate to assure that the airlock door seal integrity is maintained.
Based on the above, the staff has reevaluated the six-month test requirement and has developed a revised position which meets the objectives of Appendix J requirements for containment airlock door tests.
This revised position still requires. the containment airlock to be tested at six-month intervals at a pressure of Pa in accordance with Appendix J, except that this test interval may be extended up to the next refueling outage (up to a maximum interval between Pa tests of 24 months) if there have been I
no airlock openings since the last successful test at Pa.
The intent of the f
Appendix J requirement is to assure that the airlock door seal integrity is maintained and that no degradation has occurred as a result of opening of the L
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airlock doors between testing intervals at Pa. This position satisfies the objectives of the requirement.
The licensee has proposed that the personnel airlock be pressurized to Pa and leak-tested at an interval no longer than one operating cycle (up to a maximum interval between Pa tests of 24 months).
We find this consistent with our position and therefore acceptable, except that the six-month testing interval is still applicable if the containment airlock door has been opened since the last successful test at Pa.
The licensee will be requested to propose appropriate rodifications to the Technical Specifications.
III.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12, an exemption is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest.
Therefore, i
the Commission hereby approves the following exemption requests:
1.
Exemption is granted from the requirements of Section III.C.2 of 4
Appendix J pertaining to the Type C testing of the main steamline J
isolation valves at a test pressure of Pa to the extent that testing is to be conducted at pressure Pa. Testing at a reduced pressure of 24 psig is acceptable due to the unique design of the valves.
2.
Exemption is granted from the requirements of Section III.D.2 of Appendix J pertaining to the test-frequency for conducting Type B tests at six-month intervals at a test pressure of not less than Pa to the extent that the testing is to_be conducted at six-month i
intervals after initial fuel loading. The test interval may be-1 l
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extended beyond the six-month test interyal to the next refueling i
outage, but in nn case shall exceed 24 months from the last test at Pa, provided that there have been no airlock openings since the last successful test at Pa.
The NRC staff has determined that the erantino of this exemption will 4-not result in any significant environmental impact and that pursuant to 10 CFR 51.5(d)(4), an environmental impact statement or negative declaration and environmental impact appraisal nead not be prepared in connection with this action.
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l FOR'THE NUCLEAR REGitLATORY COMMISSTON i
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Darrell G. Eisenhut, Director Division of Licensing Office of Nuclear Reactor Regulation
' Dated at Bethesda, Maryland this 17th day of January,1984 i
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