ML20141D510
| ML20141D510 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/24/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20141D508 | List: |
| References | |
| NUDOCS 9706270236 | |
| Download: ML20141D510 (3) | |
Text
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UNITED STATES l
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NUCLEAR REGULATORY COMMISSION i
o WASHINGTON, D.C. 20066 4 001 l
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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.142 TO FACILITY OPERATING LICENSE N0. NPF-49 l
NORTHEAST NUCLEAR ENERGY COMPANY. ET AL.
MILLSTONE NUCLEAR POWER STATION. UNIT N0. 3 DOCKET N0. 50-423
1.0 INTRODUCTION
By letter dated April 15, 1997, the Northeast Nuclear Energy Company, et al.
(the licensee), submitted a request for changes to the Hillstone Nuclear Power Station, Unit No. 3 Technical Specifications (TS). The requested amendment makes changes to TS Sections 4.3.3.6 and'4.6.4.1, which require that the hydrogen monitors be periodically tested.
Specifically, the changes increase the testing interval of the monitor's hydrogen sensor, correct inconsistencies between the TS surveillances, and make changes to the Bases of the surveillances.
2.0 BACKGROUND
By letter dated January 3, 1995, the NRC issued Amendment No. 100 to the Millstone Unit 3 operating license. As part of this amendment, the NRC approved a change to the channel calibration surveillance interval associated with the hydrogen monitors from once per 92 days to once a refueling interval.
The licensee subsequently determined that the surveillance extension was not consistent with the recommendations of the equipment vendor and that a refueling interval testing frequency was not appropriate for the hydrogen sensor.
In its letter dated April 15, 1997, the licensee proposed modifying the testing interval of the hydrogen sensor to be consistent with vendor testing recommendations. The licensee also requested changes to TS Sections 4.3.3.6 and 4.6.4.1 to correct inconsistencies in surveillance testing requirements and make editorial changes.
3.0 EVALUATION TS 4.3.3.6 currently requires that each accident monitoring instrumentation channel be demonstrated operable by performance of the channel check and channel calibration at the frequencies shown in Table 4.3-7.
Table 4.3-7 requires the channel check to be performed every 31 days and the channel ca'libration to be performed every refueling interval.
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. TS 4.6.4.1 currently requires that each hydrogen monitor be demonstrated operable by the performance of a channel check at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, an analog channel operational test at least once per 92 days, and at least once each refueling interval by performing a channel calibration using sample gas containing volume perce(nt hydrogen, balance nitrogen.1) one volume percent hydrogen, ba To make the above TS consistent and incorporate the vendor testing recommendations for the hydrogen monitor sensors, the licensee has proposed i
the following changes:
1.
Change the number of TS 4.3.3.6 to TS 4.3.3.6.1 and add a new TS surveillance, TS 4.3.3.6.2.
TS 4.3.3.6.2 would require that each hydrogen monitor be demonstrated operable by a hydrogen sensor calibration and an analog channel operational test at least once per 92 days on a staggered test basis.
2.
Change the channel check testing frequency from every 31 days to every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> in Table 4.3-7.
3.
Modify the format of TS 4.6.4.1 by dividing it up into three groups based on the test frequency and adding the requirement for testing each hydrogen monitor sensor.
The proposed surveillance requirements would require that each hydrogen monitor be demonstrated operable by (1) the performance of a channel check at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (TS 4.6.4.1.a), (2) the performance of a hydrogen sensor calibration and an analog channel operational test at least once per 92 days on a staggered test basis (TS 4.6.4.1.b), and (3) the performance of a channel calibration at least once each refueling interval (TS 4.6.4.1.c).
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The renumbering of TS 4.3.3.6 to TS 4.3.3.6.1 is administrative and is acceptable to the staff. The new surveillance requirement (TS 4.3.3.6.2), in addition to the already required channel check and channel calibration l
(TS 4.3.3.6.1), would add a specific requirement to perform a hydrogen sensor calibration and an analog channel operation test once per 92 days on a staggered basis. The sensor test will be a two-point calibration, utilizing a test gas containing approximately 1 percent hydrogen for one calibration point, and approximately 4 percent hydrogen for the second calibration point.
Since (1) the calibration surveillance of the hydrogen monitor sensor is consistent.with the vendor recommended practice for maintaining sensor calibration, (2) the analog channel operation test is the same as that required by TS 4.6.4.1, and (3) adding the analog channel operation test to Section 4.3.3.6 ensures consistency within the TS; the NRC staff finds the changes acceptable.
The changing of the hydrogen monitor channel check testing frequency from every 31 days to every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> in Table 4.3-7 adds consistency between TS 4.3.3.6 and TS 4.6.4.1, since TS 4.6.4.1 requires the channel check to be performed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
The staff finds this change acceptable.
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Modifying the format of TS 4.6.4.1 by dividing it up into 3 groups based on the test frequency and adding the requirement for testing each hydrogen monitor sensor is administrative and adds consistency between TS 4.3.3.6 and 1
The staff finds these changes acceptable. The licensee has also updated the Bases to incorporate the addition of the hydrogen monitor sensor calibration and the description of the two-point calibration to be utilized in the surveillance.
l The changes in hydrogen monitor surveillance testing, along with the existing requirements, continue to provide assurance of expected instrument performance under accident conditions; therefore, the NRC staff finds the changes acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Connecticut State l
official was notified of the proposed issuance of the amendment.
The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes surveillance requirements. The NRC staff has determined l
that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (62 FR 27797 dated May 21,1997). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessigent need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, i
that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, I
and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: J. Andersen Date: June 24, 1997 i
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