ML17331A940
| ML17331A940 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 07/30/1993 |
| From: | Zwolinski J Office of Nuclear Reactor Regulation |
| To: | INDIANA MICHIGAN POWER CO. |
| Shared Package | |
| ML17331A939 | List: |
| References | |
| NUDOCS 9308190047 | |
| Download: ML17331A940 (4) | |
Text
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Hatter of INDIANA MICHIGAN POWER COMPANY Docket Nos.
50-315 and 50-316 (Donald C.
Cook Nuclear Plant Units 1 and 2)
CORRECTED EXEMPTION Indiana Michigan Power Company (the licensee) is the holder of Facility Operating License Nos.
DPR-58 and DPR-74 which authorize operation of the Donald C.
Cook Nuclear Plant, Units 1 and 2 at steady-state reactor power levels not in excess of 3250 and 3411 megawatts thermal, respectively.
The Donald C.
Cook facilities are pressurized water reactors located at the licensee's site in Berrien County, Michigan.
These licenses
- provide, among other things, that they are subject to all rules, regulations, and orders of the Nuclear Regulatory Commission (the Commission) now or hereafter in effect.
Paragraph III.D.2(b)(ii) of Appendix J of 10 CFR Part 50 requires, in part, that a full pressure air lock leakage test be performed whenever air locks are opened during periods when containment integrity is not required by the plant's Technical Specifications.
The NRC may grant exemptions from the requirements of the regulations which, pursuant to 10 CFR 50. 12(a),
(1) are authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security; and (2) where special circumstances
- are, present.
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By letter dated December 21, 1992, the licensee requested an Exemption from certain requirements of 10 CFR Part 50, Appendix J.
On July 16,
- 1993, the Commission granted the requested Exemption which was published in the Federal Re ister on July 23, 1993 (58 FR 39583).
The Exemption issued on July 16,
- 1993, included two typographical errors.
This Exemption corrects those errors and supersedes the July 16, 1993 Exemption.
In its letter dated December 21, 1992, the licensee requested an Exemption from the requirement of 10 CFR Part 50, Appendix J, III.D.2(b)(ii) identified in section II above, and substitution of an air lock door seal leakage test (Paragraph III.D.2(b)(iii)of Appendix J, 10 CFR Part
- 50) for the full pressure air lock test otherwise required by Paragraph III.D.2(b)(ii) when the air lock is opened while the reactor is in cold shutdown (Node 5) or refueling (Node 6), if no maintenance has been performed on the air lock that could affect its sealing capability.
The exemption would also allow the door seal leakage rates test of III.D.2(b)(iii)to be used when the maintenance affecting the air locks sealing capability was performed only on the door gaskets.
That is, door seal testing will be done after each opening, after maintenance which could affect the air lock door gaskets, and prior to establishing containment integrity. If maintenance that could affect sealing capability has been performed on an air lock, other than the door gaskets, a
full pressure air lock test must still be performed.
If an air lock is opened during Nodes 5 and 6, Paragraph III.D.2(b)(ii) of Appendix J requires that an overall air lock leakage test at not less than the calculated peak containment pressure from a design-basis LOCA (Pa) be conducted before plant heatup and startup (i.e., entering Node 4).
The existing air lock doors are so designed that a full-pressure (i.e.,
Pa
= 12.0 psig) test of an entire air lock can only be performed after strongbacks (structural bracing) have been installed on the inner door.
Strongbacks are needed because the pressure exerted on the inner door during the test is in a direction opposite" to that of the accident pressure direction.
Installing strongbacks, performing the test, and removing strongbacks requires at least 8
hours per air lock (there are two air locks) during which access through the air lock is prohibited.
If the periodic 6-month test of paragraph III.D.2(b)(i) of Appendix J and the test required by paragraph III.D.2(b)(iii)of Appendix J are current, no maintenance (other than to door gaskets) has been performed on the air lock that could affect its sealing capability, and the air lock is properly sealed, there is no reason to expect the air lock to leak excessively just because it has been opened in Mode 5 and Mode 6.
Accordingly, the Commission concludes that the licensee's proposed approach of substituting the seal leakage test of paragraph III.D.2(b)(iii) for the pressure test of paragraph III.D.2(b)(ii) of Appendix J is acceptable following door gasket maintenance and/or prior to entering Mode 4.
Furthermore, the licensee has committed to meet the requirements of paragraph III.D.2(b)(ii) of Appendix J whenever other maintenance that could affect sealing capability has been performed on the air lock.
The special circumstances for granting this exemption pursuant to 10 CFR
- 50. 12 have also been identified.
The purpose of paragraph III.D.2(b)(ii) is to ensure that air locks are properly sealed when containment integrity is required.
The proposed alternative test method is sufficient to achieve this underlying purpose in that it provides adequate assurance of continued leak tight integrity of the air lock.
Consequently, the special circumstances
I 1
~
des'cribed by 10 CFR 50.12(a)(2)(ii) and (iii) exist in that application of the 1,
1 regulation in these particular circumstances is not necessary to achieve the underlying purpose of the rule in that the licensee has proposed an acceptable alternative test method that accomplishes the intent of the regulation.
Compliance would result in undue hardship that would be sign'ificantly in excess of that contemplated when the regulation was adopted in that plant startup would be delayed while an overall air lock leakage test was performed at full pressure.
The effort and delay required is not warranted by the resulting safety benefit.
IV.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50. 12, this exemption as described in Section III above is authorized by law, will not present an undue risk to 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) and (iii) are present justifying the exemption.
Therefore, the Commission hereby grants the exemption as described in Section III above from 10 CFR Part 50, Appendix J, III.D.2(b)(ii).
Pursuant to 10 CFR 51.32, the Commission has determined that the granting of this Exemption will have no significant impact on the environment (58 FR 35984).
This Exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION ORIGINALS SIGNED BY Dated at Rockville, Maryland thi s 30<h da of July.
John A. Zwolin'ski, Acing Director Division of Reactor Projects - III/IV/V Office of Nuclear Reactor Regulation OFFICE LA:PD31 PE:PD31 A D: PD31 OGC
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