ML17056C182
| ML17056C182 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 12/24/1992 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | NORTHERN STATES POWER CO. |
| Shared Package | |
| ML17056C183 | List: |
| References | |
| NUDOCS 9212300246 | |
| Download: ML17056C182 (10) | |
Text
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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NIAGARA MOHAWK POWER CORPORATION
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(Nine Mile Point Nuclear Station
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Unit No.
1)
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Docket No. 50-220 EXEMPTION Niagara Mohawk Power Corporation (NMPC or the licensee) is the holder of Facility Operating License No. DPR-63, which authorizes operation of Nine Mile Point Nuclear Station Unit No.
1 (the facility or NMP1), at a steady-state reactor power level not in excess of 1850 megawatts thermal.
The facility is a boiling water reactor located at the licensee's site in Oswego County, New York.
The license provides among other things, that it is subject to all rules, regulations, and Orders of the U.S. Nuclear Regulatory Commission (the Commission or NRC) now or hereafter in effect;Section III of Appendix J to 10 CFR Part 50 requires the development of a program to conduct periodic leak testing of the primary reactor containment and related systems and components, and components penetrating the primary containment pressure boundary.
The interval between local leak rate tests for containment isolation valves (Type C tests) is specified by Section III.D.3 to be no greater than 2 years.
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By letter dated November 3,
- 1992, NHPC requested a one-time only exemption (for a maximum of 7 weeks) from the requirements of 10 CFR Part 50, Appendix J, Section III.D.3, regarding periodic retest schedules for 39 Type C
tests.
This letter superseded an application from NNPC dated October 14, 1992.
The requested exemption would permit continued operation of the facility until its next refueling outage, which will begin no later than February 19, 1993.
Otherwise, the required testing would require a plant shutdown 7 weeks before the end of the current fuel cycle.
IV.
Section III.D.3 of Appendix J to 10 CFR Part 50 states that Type C tests shall be performed during reactor shutdowns for refueling, at an interval not to exceed 2 years.
The licensee has requested a one-time exemption from the regulations.
The 2-year interval requirement for Type C testing is intended to be often enough to preclude significant deterioration between tests and long enough to permit the tests to be performed during routine plant outages.
Leak rate testing of containment isolation valves during plant shutdown is preferable because of the lower radiation exposures to plant personnel.
Furthermore, some containment isolation valves cannot be tested at power.
For those valves that cannot be tested during power operation, or fo'r which testing at power would yield unnecessary radiation exposure of personnel, the
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Commission staff believes the increase in confidence of containment integrity following a successful test is not significant enough to justify the hardships and costs associated with a plant shutdown specifically to perform the tests within the 2-year time period.
V.
The Commission has determined that pursuant to 10 CFR 50. 12(a)(1) this exemption 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), are present justifying the exemption; namely, that application of the regulation in the particular circumstances is not necessary to achieve the underlying purpose of the rule.
The underlying purpose of Section III.D.3 of Appendix J to 10 CFR Part 50 is to provide an interval short enough to prevent serious deterioration from occurring between tests and long enough to permit testing to be performed during regular plant outages.
For containment isolation valves that cannot be tested at power, or for containment isolation valves where testing at power involves unreasonable risk to personnel and equipment, the increased confidence in containment integrity following successful testing is not significant enough to justify a plant outage merely to perform the tests within the 2-year interval.
The licensee has presented information accepted by the Commission, which gives a
high degree of confidence that the components affected by this exemption will not degrade to an unacceptable extent.
Acceptable leakage limits are defined in Sections III.B.3(a) and III.C.3 of Appendix J to 10 CFR Part 50.
Pursuant to 10 CFR 51.32, the Commission has determined that granting this Exemption will not have a significant impact on the environment (57 FR 54621).
This Exemption is effective upon issuance and shall expire on February 20, 1993.
FOR THE NUCLEAR REGULATORY COMMISSION Dated at Rockville, Maryland, this 24t?day of December 1992 e
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recto Division of Reactor Proj s - I/II Office of Nuclear Reactor egulation
Pursuant to 10 CFR 51.32, the Commission has determined that granting this Exemption will not have a significant impact on the environment (57 FR 54621).
This Exemption is effective upon issuance and shall expire on February 20, 1993.
FOR THE NUCLEAR REGULATORY COMMISSION 1
Original signed by:
Dated at Rockville, Maryland, this24<~day of December 1992 Steven A. Varga, Director Division of Reactor Projects I/II
,Office of Nuclear Reactor Regulation
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