ML20082B703
| ML20082B703 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/27/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20082B701 | List: |
| References | |
| NUDOCS 9504050277 | |
| Download: ML20082B703 (3) | |
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UNITED STATES j
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NUCLEAR REGULATORY COMMISSION j
o WASHINGTON, D.C. 20$66-0001 f
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l
RELATED TO AMENDMENT NO.186 i
TO FACILITY OPERATING LICENSE NO. DPR-65 i
NORTHEAST NUCLEAR ENERGY COMPANY i
THE CONNECTICUT LIGHT AND POWER COMPANY l
THE WESTERN MASSACHUSETTS ELECTRIC COMPANY HILLSTONE NUCLEAR POWER STATION. UNIT NO. 2 l
DOCKET NO. 50-336 l
1.0 INTRODUCTION
By letter dated April 22, 1994, the Northeast Nuclear Energy Company'(the j
licensee) submitted a request for changes to the Millstone Nuclear Power Station, Unit No. 2 Technical Specifications (TS). The requested changes 4
j would delete the operability and surveillance requirements (SR) of the condenser air ejector (CAE) radiation monitor from the Millstone Unit 2 l
Technical Specification Tables 3.3-12 and 4.3-12.
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2.0 EVALUATION t
i The CAE monitor and the steam generator (SG) blowdown monitor are gross j
radioactivity monitors which provide automatic termination of SG blowdown discharge at the trip set points of the monitors. Currently, TS Table 3.3-12 requires the operability of one of these two monitors in operational Modes 1 through 5 and in Mode 6 when the SG blowdown pathway is used. This is because either of these monitors can automatically terminate the SG blowdown discharge. The CAE monitor is included in the current TS Tables 3.3-12 and l
4.3-12 because at the time when these tables were formalized, it was believed i
that the CAE monitor could be an alternative monitor to the SG blowdown 3
monitor for monitoring and isolating the SG blowdown.
Specifically, it was j
then believed that typical causes of increased SG blowdown activity, such as i
increased primary coolant activity or increased primary to secondary leakage, would translate into corresponding increased activities in the streams i
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monitored by both the CAE and SG blowdown monitors.
From its operational experience, the licensee found that this is not necessarily true for all
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operating conditions, and that SG blowdown stream activity can increase without causing a corresponding increase in the activity in the stream i
monitored by the CAE monitor.
In its April 22, 1994 submittal, the licensee 4
provided two examples to illustrate when this lack of correlation between SG blowdown stream activity and CAE stream activity can occur. As a first i
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i example, the licensee pointed out that a plant trip following an extended period of primary to secondary leakage can cause long lived secondary side i
i activity (e.g., Cs-137) to come out of " hide out" in the SG, resulting in an-i increase in the SG blowdown activity without a corresponding increase in the activity in the stream monitored by the CAE monitor. As a second example, the j
licensee pointed out that a reduction in the SG blowdown flow with all other parameters held constant, will cause an increase in the SG blowdown l
concentration without a corresponding increase in the activity in the stream monitored by the CAE monitor. Accordingly the CAE monitor which would be deleted from the TS is not as accurate as the SG blowdown monitor which is i
being retained in the TS.
For the above reasons, the licensee concluded that the CAE monitor does not adequately monitor or isolate SG blowdown under all-1 operating conditions. Therefore, the licensee proposed deletion of the i
operability and SR for the CAE monitor identified in the Millstone Unit 2 TS Tables 3.3-12 and 4.3-12.
The licensee further proposed deletion of l
applicable portions of notes (i.e., portions of notes applicable to the CAE 1
monitor) to TS Tables 3.3-12 and 4.3-12 to be consistent with its proposed i
deletion of the operability and SR for the CAE monitor from the above tables.
The licensee further justified its proposed license amendment to Millstone i
Unit 2 TS for liquid effluent monitoring instrumentation stating that it is more conservative than the existing TS for liquid effluent monitoring i
instrumentation, since it imposes stricter limitations on the operation of Millstone Unit 2.
The licensee stated that this is because the proposed TS change requires the use of a single radiation monitor, the SG blowdown monitor j
(instead of either the SG blowdown monitor or the CAE monitor as allowed by
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the existing TS), to meet the requirements of Millstone Unit 2 TS 3.3.3.9, i
" Radioactive Liquid Effluent Monitoring Instrumentation." Additionally, the j
licensee stated that although the operability and SR of the CAE monitor will be deleted from Millstone Unit 2 TS if NRC approves the licensee's requested t
TS change, the design features, functions and currently specified J
surveillances and frequencies for such surveillances will not be changed and that the CAE monitor will continue to isolate the SG blowdown upon a high i
radiation alarm.
In a telephone conversation with the staff on July 27, 1994, l
the licensee clarified that the surveillances and their frequencies for the CAE radiation monitor, identified in the existing Millstone Unit 2 TS Tables j
3.3-12 and 4.3-12, will be relocated in plant controlled procedures and documentation.
Based on the discussion above, the staff finds the CAE monitor is not 3
necessary to assure the protection of the public health and safety and the proposed deletion is acceptable.
In this context, the staff notes that the i
deletion of the CAE monitor from the TS tables on liquid effluent monitoring l
instrumentation for Millstone Unit 2, does not compromise the plant's i
capability to monitor, prior to release to environs, the gaseous effluent from j
the CAE. The staff finds that the stack radiation monitor will monitor the j
above release as well as releases from some other sources (see Millstone Unit j
2 TS Tables 3.3-13 and 4.3-13 and FSAR Section 10.4.2).
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3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a 3
facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves no si'gnificant increase in the amounts, and no significant change in the types, of any effluents that may be released i
offsite, and that there is no significant increase in individual or cumulative i
occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards l
consideration, and there has been no public comment on such finding (59 FR j
27058). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR t
51.22(b) no environmental impact statement or environmental assessment need be j
prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
i The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the 4
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.
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Principal Contributor:
T. Chandrasekaran 4
i Date:
March 27, 1995 l
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