ML20137Z388
| ML20137Z388 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 03/03/1986 |
| From: | Bernero R Office of Nuclear Reactor Regulation |
| To: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| Shared Package | |
| ML20137Z391 | List: |
| References | |
| NUDOCS 8603130030 | |
| Download: ML20137Z388 (8) | |
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of Philadelphia Electric Company Docket No. 50-352 Limerick Generating Station Unit 1 EXEMPTION I
The Philadelphia Electric Company (PECo./the licensee) is the holder of Facility Operating License No. NPF-39 which authorizes operation of the Limerick Generating Station, Unit 1 at a power level not in excess of 3293 megawatts thermal for each unit. The facility is a boiling water reactor located at the licensee's site in Montgomery County, Pennsylvania.
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.
II Paragraphs III.C.3 and III.D.3 of Appendix J to 10 CFR Part 50 require that containment isolation valves which may provide a pathway for leakage of con-tainment atmosphere are required, on at least a 24 month frequency, to have their leakage measured for comparison with the limiting value of 0.6 L, for Type B and Type C tests.
8603130030 303]
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,i The Philadelphia Electric Company proposed a one-time extension to the i
Surveillance Requirements for Technical Specification 4.6.1.2 which would j
allow the 24 month interval for conducting Type C tests with gas on 27 iso-l lation valves to be extended by 12 weeks until May 26, 1986. The staff has found that approval of the proposed extension is warranted and is authorized by the granting of this one-time exemption so that Unit 1 may continue to operate until a shutdown is required on May 26, 1986 to perform other extensive surveillance and maintenance activities.
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III The NRC staff has evaluated the licensee's basis for requesting the extension in the surveillance interval and finds that not granting this exemption would require the licensee to shut down the plant on March 3, 1986 for a period of j
about two weeks to conduct the testing. Granting of this exemption is likely to result in a negligible reduction in containment integrity during the 12 week extension period.
In evaluating the changes to the Technical Specifications and the associated exemption, the staff reviewed the licensee's technical justifications for the requested extension. The staff reviewed the licensee's l
position that these tests cannot be conducted during power operations and that therefore a shutdown would be required to perform the tests. The staff reviewed the types of valves involved to ascertain that these are not the types of valves used in boiling water reactors which have a greater propensity to require intensive maintenance to maintain their leaktight integrity. The staff considered the uses
. l of these valves to ascer'ain that they are not used during normal plant operations in the relatively more demanding applications such as modulating valves to continuously control flow rates or pressure. The staff reviewed available data provided by the licensee on similar valves used elsewhere in the industry which supports the licensee's position that these valves have traditionally good maintenance histories in the industry. The staff also reviewed previous leakage test results on the specific valves subject to the exemption reqJest and has found that there is substantial rargin between the values previously measured and the limiting values in Appendix J and the Tech-nical Specifications to accommodate any additional degradation likely to occur during the period of the extension. The details of the above described review are discussed in the attached Safety Evaluation.
Based on the information provided by the licensee, the staff's evaluation of the licensee's submittals, the hRC staff concludes that the licensee has provided an adequate basis for the conclusion that postponing the subject local leak rate tests until May 26, 1986 is likely to have little or no effect on containment integrity.
The Commission has amended its regulations, effective on January 13, 1986, in 10 CFR 50.12 (50 FR50764-50778) to modify the criteria for granting exemptions from its regulations. The amended regulations in 10 CFR 50.12 state that the Commission will not consider granting an exemption unless special circumstances are present.
In its letter of February 25, 1986 the licensee has addressed two of those special circumstances which are applicable to this exemption request.
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- q. I The licensee states that the special circumstances of 10 CFR 50.12 (a)(2)(ii) are present in that application of the regulation in 10 CFR 50, Appendix J i
for the Type C leakage testing of 27 containment isolation valves within 24 months, i.e. by March 3, 1986, of their initial tests versus the requested i
i one-time extension until May 26, 1986 is not necessary to achieve the under-i
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lying purpose of the rule. Appendix J states that a purpose of the tests is j
to assure that leakage through the primary reactor containment and systems I
and components penetrating primary containment shall not exceed allowable j
leakage rate values as specified in the technical specifications or associated l
l bases.
The licensee has provided various bases for its conclusion that the reouested j
l delay of 12 wecks is not likely to result in a situation wherein the measured leakage from these valves would cause the limitations of the technical specifi-cations to be exceeded. These bases, which are discussed in more detail in j
the enclosed Safety Evaluation and the licensee's submittals, include the licensee's characterization of these valves as being of the type which tradt-l I
tionally have good maintenance histories, are not used in the relatively more j
j demanding applications and which have shown in their initial leakage tests j
that they do not contribute an undue proportion of either the total measured containment leakage or the technical specification allowable leakage values.
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On these bases the staff agrees that it is unlikely that the delay in the
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testing of the subject 27 valves would result in measured leakage that would cause the allowable technical specification values to be exceeded. Thus the 1
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NRC staff concludes that the underlying purpose of Appendix J in this regard, l
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. to provide assurance that leakage shall not exceed technical specification allowable values, will be met with this one-time extension of the test schedule.
The licensee also states that the special circumstances of 10 CFR 50.12 (a)
(2)(v) are present in that the exemption would provide only temporary relief from the applicable regulation and the licensee has made good faith efforts to comply with the regulation, i
The exemption is temporary since it provides relief from the requirement to conduct the subject tests only from March 3, 1986 until during a shutdown which shall begin no later than May 26, 1986. The licensee submits that it has made a good faith effort to comply with the requirements of the regulation in that it has tested all but 27 valves out of a total population of over 200 valves subject to such testing by the date initially required by Appendix J and the technical specifications. The licensee also describes its attempts I
to minimize the number of valves which would require the schedular relief by proceeding with the tests of all valves necessary to permit operations until May 26, 1986 which could be tested without requiring the shutdown of the plant.
This effort was undertaken following the delay between the completion of low
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power testing activities and issuance of the full power license. Thus the NRC staff concludes that the requested exemption meets the criterion of pro-viding only temporary relief and has been accompanied by a good faith effort to comply with the regulation.
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. Based upon the staff's findings that postponing the local leak rate tests from March 3 until May 26, 1986 is likely to have little or no effect on containment integrity and the staff's assessment of the special circumstances associated with this request for an exemption the NRC staff finds that operation of Limerick Unit I during the proposed extension period is acceptable. Therefore.
the staff finds that the proposed temporary exemption from 10 CFR 50, Appendix J.
Paragraph 111.0.3 is acceptable.
i IV 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 interast. Therefore, the Commission hereby grants the exemption as follows:
l' "An exemption is granted from the requirement to conduct Type C testing on containment isolation valves at an interval no greater than 24 months as stated in 10 CFR 50, Appendix J. Paragraph III.D.3. This exemption is granted for the perind specified in the licensee's December 18, 1985 reouest for exemption (from March 3, 1986 until May 26, 1986) and is i
only applicable to 27 valves in Limerick Unit 1 as indicated in the modified Technical Specification Table 3.6.3-1 accompanying the issuance of Amendment fio. 2 to License flo. NPF-39."
i Pursuant to 10 CFR 51.32, the Commission has determined that the issuance of the exemption will have no significant impact on the environment (SIFR7344, March 3, 1986).
. A copy of the Commission's Safety Evaluation dated March 3, 1986 related to this action is available for public inspection at the Comission's Public Document Room, 1717 H Street, N.W., Washington, DC and the Po'.tstown Public Library, 500 High Street, Pottstown, Pennsylvania 19464.
This Exemption is effective upon issuance and is to expire at midnight on May 26, 1986.
FOR THE NUCLEAR REGULATORY CCMMISSION l
M ** w Robert Bernero, Director Division of BWR Licensing Cated at Bethesda, Maryland this 3rd day of March 1986
. A copy of the Commission's Safety Evaluation dated March 3, 1986 related to this action is available for public inspection at the Commission's Public Document Room 1717 H Street, N.W., Washington, DC and the Pottstown Public Library, 500 High Street, Pottstown. Pennsylvania 19464.
This Exemption is effective upon issuance and is to expire at midnight on May 26, 1986.
FOR THE NUCLEAR REGULATORY COMMISSION Origiani si,,,a sy,
Robert Bernero, Director Division of BWR Licensing Dated at Bethesda, Maryland inau t s this 3rd day of February 1986 PD#4/PM PD#4/LA EB/ Dbl /C OELD PD#4/D RMartin ml EHylton BDLiaw WButler 2/
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