ML20217M754
| ML20217M754 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 08/19/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20217M750 | List: |
| References | |
| NUDOCS 9708250272 | |
| Download: ML20217M754 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION
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E WASHINGTON, D.C. 30666 4001 l
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR RFACTOR REGULATION REL ATED TO AMENDMENT NO.133 TO 3
FACILITY OPERATING LICENSE NO. NPF-38 ENTERGY OPERATIONS. INC.
WATERFORD STEAM ELECTRIC STATION. UNIT 3 QQQi[T NO. 50-382
1.0 INTRODUCTION
h By application dated April 11, 1997, Entergy Operations, Inc. (the licensee),
submitted a request for changes to the Waterford Steam Electric Station, Unit 3, Technical Specifications (TSs). The requested changes would modify TS 3.3.3.7.3, and Surveillance Requirements (SR) 4.3.3.7.3 for the broad range gas detection system. Also it would make some changes to the Bases in Section 3/4.3.3.7 to incorporate information associated with the proposed modifications. The licensee is planning to replace the existing toxic gas monitors in the system with a new, more advanced gas monitors.
These new gas monitors operate on different principle and require, therefore, different operating procedures.
The proposed changes to the current TS will account for these differences.
2.0 EVALUATION The current toxic gas detection system has a photoionization detector, a local readout and alarm adjustment for detection of toxic gases and isolation of the control room. This system proved to be unreliable, requiring excessive amount of maintenance and calibration efforts. The new monitors, which the licensee proposes to use, are based on a Fourier Transform Infrared (FTIR) analysis technique. This technique utilizes microprocessor gas analysis based on infrared spectrum analysis.
It is more accurate than the method used currently. Also, one of its advantages is that the new monitors allow the operators to adjust gas concentration setpoints individually for each gas to the limits defined by the lowest Immediately Dangerous to Life or Health (IDLH) values. The modified taxic gas detection system will not include any changes to the existing alarms and control room isolation function.
The modified system will be able to measure all gases of concern with the exception of chlorine. A separate chlorine monitor will be provided in the new system. However, this monitor will not be seismically qualified and in order to ensure chlorine monitoring under adverse accident conditions, the licensee will leave the existing, seismically qualified monitor in place in the modified system and use the new chlorine monitor as a backup unit.
9708250272 970819 PDR ADOCK 05000382 P
2-The new gas monitor will be perforn:ng automatic calibration once every one to four haurs with a ty>ical value of once mery two hours. This calibration is required to establisi a baseline reference for the infrared spectrum.
During the calibration period, which will last one minute, the monitor will not be available for monitoring presence of toxic gases. Although there are two monitoring trains in the system and calibration periods are staggered, there is a possibility that with one monitoring train inoperable (e.g., being serviced), the system will not be able to monitor toxic gases for as long as one minute. The licensee evaluated this case by performing probabilistic analysis. The results of this analysis have indicated that the probability of incapacitation of the operators, due to the absence of toxic gas monitoring, is below the level that is considered acceptable risk in Section 2.2.3 of the Standard Review Plan.
Interruption of the monitoring operation during calibration period will not, therefore, significantly affect the safety of the plant.
In order to account for the differences in the operating procedures for the new toxic gas detection system, the licensee amended the TS as follows.-
In LCO 3.3.7.3 a footnote was added stating that the requirement for maintaining the system operable does not apply during the time (approximately one minute) when the instrument automatic background / reference spectrum check renders the instrument inoperable.
In SR 4.3.3./.3 a change was introduced modifying the channel functional test to account for the new calibration procedure.
The Bases in Section 3/4.3.3.7 were modified to include a description of the new toxic gas detection system, its operation and its calibration procedure.
The staff has evaluated the licensee's proposed modification to the TS for the toxic gas detection system. The licensee would like to modify these TS to make them applicable to the new toxic gas monitors it plans to install in the system. These new monitors provide better monitoring and contribute to an improved detection of the toxic gases in the plant. The licensee addressed two problems related to the usc of these new monitors:
interruption in monitoring operation during monitor calibration and lack of seismic qualification for the new chlorine monitor.
In both these cases the licensee found an acceptable solution and was able to demonstrate that satisfactory operation of the modified system could be achieved. The staff has evaluated the licensee analyses and based on its evaluation concludes that the proposed amendment to the TS for the toxic gas detection system is acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Louisiana State official was notified of the proposed issuance of the amendment. The State official had no consents.
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4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a 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 significant increase in the amounts, and no
. significant change in the types, of any effluents-that may be released
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offsite, and that there is no significant increase in f ndividual or cumulative occupational radiation exposure. The Commission has previously issued a pro-posed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (62 FR-24987).
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 assessment need be prepared in l
connection with the issuance of the amendment.
5.0 SQNCLUSION The Commission has concluded, based on the considerations discussed above, 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, and (3) the issuance of the amendment will not be-inimical to the common defenss and security or to the health and safety of the public.
Principal _ Contributor:
K. Parczewski Date: August 19. 1997
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