ML18051B049
| ML18051B049 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/29/1984 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8409060275 | |
| Download: ML18051B049 (5) | |
Text
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l consumers Power company General Offices: 1945 West Parnall Road, Jackson, Ml 49201 * (517) 788-0550 August 29, 1984
- Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
10CFR50 APPENDIX J INTERPRETATION -
CONTAINMENT AIR LOCK TESTING This interpretation of 10CFR50 Appendix J, III, D, 2. (b) (i), (ii).and (iii) is provided in response to concerns raised by the Palisades Plant staff regarding testing of the entire personnel airlock at internal pressures of not less than the peak calculated accident pressure (Pa).
The Pa test requires approximate-ly 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to conduct (includes set-up, pressurization, decay and dismantling of test equipment) whereas a between-the-seals test may be performed in approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
In the past, the Palisades Plant staff has conservatively interpreted the requirements of paragraph III, D, 2.(b)(ii) that a test of the entire air lock assembly before returning to power operations following a cold shutdown is required. Since the Palisades Plant Technical Specifications do not require containment integrity to be maintained during cold shutdown, this same require-ments implies that a Pa test must be performed any time a forced outage places the plant in a cold shutdown mode regardless of the fact that -
- 1) containment integrity was indeed maintained throughout the duration of the outage; and, 2) a Pa test of the air lock assembly is performed every six months.
Appendix J, III, D, 2.(b)(iii) permits a between-the-seals test for air locks having testable seals.
This test, in accordance with III, D, 2.(b)(iii) is performed at the Palisades Plant during periods of power operation (or any period where containment integrity is required) following an entry into the containment.
NRC staff guidelines (reference the attachment to this letter which was supplied by letter to the Big Rock Point Docket No 50-155, dated August 4, 1980) provide further guidance for an "intermediate test" of the door seals whenever containment integrity is required.
Consumers Power Company, having reviewed the attached Staff position interprets the inter-mediate test as also applicable during periods where containment integrity is not required provided the following requirements have been satisfied:
8409060275 8408~9 ~
~DR ADOCK 05000255 PDR OC0884-0015A-NL02
Director, NRR Palisades Plant CONTAINMENT AIR LOCK TESTING August 29, 1984 2
- 1.
A test of the entire air lock assembly is performed once every six months at Pa.
- 2.
A reduced-pressure test is performed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of every first-of-a series of openings during the interim, between the six month tests.
- 3.
Containment integrity has been maintained since the last Pa test.
We believe this interpretation is consistent with NRC staff positions and objectives of the air lock-testing requirements.
Discussions with the Resident Inspector - Region III and a representative of your staff regarding this information occurred on August 27 thru 29, 1984.
The Palisades Plant Review Committee has also reviewed this interpretation and has found it does not constitute on unreviewed safety question. Procedures have been revised accordingly.
~~~*
Thomas C Bl>~
Staff Licensing Engineer CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades Attachment OC0884-0015A-NL02
OC0884-0015B-NL02 ATTACHMENT Consumers Power Company Palisades Plant -*Docket 50-255 10CFR50 APPENDIX J INTERPRETATION CONTAINMENT AIR LOCK TESTING 2 Pages
APPENDIX A CONTAINMENT AIRLOCKS Appendix J to 10CFRSO requires that reactor containment airlocks be leak-tested at the peak calculated accident pressure (Pa) at six-month intervals.
Further, should the airlocJc,s be opened during such intervals, the airlocks will be leak-tested after each opening.
Appendix J calls out these specific require-ments for airlocks because they present potentially large leakage paths which are subject to human error to a larger degree thaii other potential leakage paths.
The staff's interpretation of the objectives of the airlock-leak-testing requirements are:
- 1. That the six-month test will provide an integrated leakage rate for the entire airlock assembly including electrical and mechani=
cal penetrations, *the airlocks cylinder; hinge assemblies, welded connections, and other potential leakage paths.
- 2.
That the "after-each-opening" test would provide a means of ensur-ing that the door seals had not been damaged or seated improperly during airlock use.
For those operating facilities that were designed and constructed prior to the issuance of Appendix J, consideration has beeri given to the alternatives to the specific testing requirements which will meet the provisions of Appendix J.
Listed below are a number of guidelines which may be useful when considering or revising current airlock:...leak.;.testing*programs.
- 1.
At six-month intervals the entire airlock assembly shall be leak-tested at the peak pressure, Pa.
If the test pressure will lift the inner airlock door off its seat, a strongback or other mechani-cal device should be used so that meaningful test results can be obtained at Pa.
- 2.
Should the airlock be opened during the interval between the six-month tests., the airlock door seals shall be tested within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of every first of a series of openings. This relaxation in the "after-each-opening" test requirement of Appendix J recognizes that a significant amount of time is required to conduct these intermediate tests in relation to the frequency of.use of *the air-lock.
These tests would be conducted whenever containment integ-rity is required.
J.
For those plants which require the use of a strongback or clamps to leak-test the door seals at a pressure, Pa, a lower pressure (e.g., manufacturer's recommended pressure, which would not require the use of such clamping devices) should be used to con-duct the intermediate tests. The results of leakage tests at the A-l:
reduced pressure must be conservatively extrapolated to the leakage at the accident pressure, Pa, to determine accept-ability.
(The extrapolation to be utilized must be submitted to the NRC.)
In lieu of the intermediate tests, an acceptable alternative would be the use of a continuous monitoring system to achieve the objective of the "after-each-opening" test requirement.
As in the case of the reduced-pressure inter-mediate test, it must be demonstrated that the continuous monitoring system is sufficiently sensitive to detect unacceptable leak.age rates and that the accept-able leakage-rate limits will be based upon a conservative extrapolation to the limiting leakage rate experienced under accident conditions (e.g., at a pressure of Pa).
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