ML20128B805
| ML20128B805 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/29/1993 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | NORTHEAST NUCLEAR ENERGY CO. |
| Shared Package | |
| ML20128B808 | List: |
| References | |
| NUDOCS 9302030180 | |
| Download: ML20128B805 (6) | |
Text
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9:
UtilTED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
{
in the Matter of NORTHEAST NUCLEAR ENERGY COMPANY
)
Docket No. 50-423 (Millstone Nuclear Power Station, Unit 3) i
)
EXEMPTION 1.
Northeast Nuclear Energy Ccmpany (the licensee) is the holder of Facility Operating License No NPF-49, which authorizes operation of H111 stone Nuclear Power Station, Unit No. 3.
The license provides,.among other things, that the facility is subject to all rules, regulations, and orders of the Commission now or hereafter in effect.
The-facility consists of a pressurized-water reactor located at.the licensee's site in New London County, Connecticut, 11.
One of the conditions of all operating licenses for water-cooled power reactors, as specified in 10 CFR 50.54(o), is that primary reactor containments shall meet the containment leakage test requirements set forth 'in 10 CFR Part 50, Appendix.J.- More specifically the following sections require that:
9302030180 930129 DR ADOCK 0500 W
.y Section Ill.D.2.fa). "Tvoe B Tests" Type B tests, except tests for air locks, shall be perforned during reactor shutdown for refueling or other convenient intervals but in no case at intervals greater than 2 years.
Section III.D.3. "Tvoe C Tests" Type C tests shall be performed during each reactor shutdown for refueling but in no case at intervals greater than 2 years.
III.
A.
Exemotion for Temocrary Relief By letter dated November 18, 1992, the licensee requested a one-timo schedular exemption for the local leak rate tests (LLRTs) from the requirements of 10 CFR 50, Appendix J, Sections Ill.0.2(a) and III.D.3 to accommodate a schedule change for the next refueling outage. The request for-exemption, if granted, would exceed the required Type B and C test interval by approximately 10 months.
In addition, the licensee proposed Technical Specification (TS) changes to reflect tht above cited exemption request. The staff's evaluation of the licensee's exemption request is provided in the -
Safety Evaluation dated January 29, 1993, supporting Amendment No. 75, and is sunmarized below.
At Millstone Unit 3, there are 84 Type B penetrations which require Type B testing. The licensee plans to test all of these penetrations in accordance with the schedule required by Appendix J, except for the fuel transfer canal.
blind flange that cannot be tested at power.
A schedular exemption was requested for the fuel transfer canal blind flange, which was last tested on March 18, 1991.
There are 68 mechanical penetrations that require Type C testing. All but 31 of these were tested when opportunities occurred during outages in the l
1
. last year.
Schedular exemption for testing the remaining 37 penetrations..ere requested because they either cannot be tested during plant operation, or would cause a degradation in safety if tested during plant operation. All of these penetrations were tested during the 1991 refueling outage.
i The Technical Specifications contain a combined leakage rate limit for all penetrations and valves subject to Type B and C testing. The last measurement of combined Type B and C leakage during the 1991 refueling outage was 37.5% of the Technical Specification limit.
The projected leak rate at the end of the 10-month period, during which this exemption from Type B and C testing applies, would be less than 50% of Technical Specification limits for combined Type B and C leakage.
Based on the foregoing, the NRC staff concludes that a schedular exemption is technically justified.
B.
10 CFR 50.12 Determina.t.11qs for Soggial Circumstances On January 22, 1991, ar.d February 5, 1991, the licensee (Northeast Nuclear Energy Company) commenced the most recent containment LLRTs in accordance with the above Type B and C periodic testing requirements, respectively, for the Hillstone Unit 3 during the 1991 refueling outage. As a result of an unusually long maintenance outage due to the service water system work and erosion / corrosion work during 1991, and two limited duration outages in 1992, the licensee has rescheduled the next refueling outage from November 1992 to approximately September 1993. With the new outage schedule, the opportunity for performing the required tests would exceed the required interval by about 10 months.
At Hillstone Unit 3, there are 84 Type B penetrations which require Type B testing.
Of the 84 penetrations, 80 are electrical penetrations which can be tested at power.
The licensee is conducting Type B testing of these penetrations and plans to complete the testing prior to January 22, 1993. Of
4 the four remaining penetrations, two penetrations (the equipment hatch and equipment hatch manway) were tested on November 16, 1991 and January 28, 1992, respectively.
The third penetration, the personnel air lock, is covered under TS Section 3.6.1.3 and is not the subject of this request.
The fuel transfer canal blind flange which was tested (Type B) on March 18, 1991, is the only penetration that cannot be tested at power and will require an extension.
There are 08 mechanical penetrations that require Type C testing, in January, May and October 1992, while shut down, Type C testing was satisfactorily performed on 31 penetrations. This represents approximately 45% of the total Type C testing.
The exemption request is only for the remaining penetrations (37) whose last Type C tests were performed during the last refueling outage.
The staff concludes that with the unplanned outages that have occurred, with the testing that has been performed to date, and with the licensee's commitment to perform additional testing during any forced outages of sufficient duration that may occur before the next refueling outage, the licensee's good faith efforts to comply with Appendix J have been demonstrated.
The time interval of 24 months, specified in Appendix J, was based, in part, on the expected degradation of components exposed to the environment resulting fross.a full 24 months of normal plant of ration.
The total cxposure time for the containment penetration to normal p1 at operating environment-will be only about 19 months with the requested exemption.
The 24-month interval requirement for Type B and C penetrations is intended to be often enough to prevent significant deterioration from occurring and long enough to permit the LLRTs to be performed during plant outages.
In addition leak testing of the penetrations during plant shutdown l
1
E 5-is preferable because of the lower radiation exposures to plant personnel.
Moreover, some penetrations, because of their intended functions, :annot be tested at power operation.
For penetrations that cannot t,e tested during power operation or those that if tested during plant operation would cause a degradation in the plant's overall safety (e.g.. the closing of a redundant line in a safety system), the increase in confidence of containment integrity following a successful test is not-significant enough to justify a plant shut-down specifically to perform the LLRTs within the 24-month time period, in light of the above discussions.
t IV.
5 Pursuant to 10 CFR 50.12 (a)(2)(v), the Commission will not consider I
granting a schedular exemption unless the licensee has made good faith efforts to comply with the regulation.
The NRC staff believes that the licensee has taken prudent steps to improve the containment integrity and, if not for the change in refueling outage schedule caused by unexpected outages, would have complied with Appendix J.
Based on our evaluation, the NRC staff has concluded that the'11censee has made a good faith effort to comply with the requirements.of Appendix J and thatthespecialcircumstancesasdescribedin10CFR50.12(a)(2)(v)existin that the exemptions would provide only-temporary relief from the applicable regulations. Therefore, the staff has determined that.the schedular.
exemptions from 10 CFR Part 50, Appendix J should be granted.
Accordingly, the Commission has determined that pursuant to 10 CFR 50.12, the exemption is authorized by law, will not endanger life or property or the common defense and security, and is otherwise in the public. interest.
Therefore, the Commission hereby approves.the following exemption request.
6-A temporary exemption is granted from the requirements of Sections Ill.D.2.(a) and 111.D.3, which require a local leak rate test to be conducted at intervals not greater than 24 months, for good cause shown, this exemption extends that interval by approximately 10 months from February 5, 1993, to the next refueling outage, but no later than December 5,1993.
Pursuant to 10 CFR 51.32, the Commission has determined that the granting of these exemptions will have no significant impact on the quality of the human environment (58 FR 5035).
This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Original signed by Steven A. Varga, Director Division of Reactor Projects - 1/II Office of Huclear Reactor Regulation Dated at Rockville, Maryland this 29th day of January 1993
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