ML20236U797
| ML20236U797 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/28/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20236U796 | List: |
| References | |
| NUDOCS 9807310077 | |
| Download: ML20236U797 (4) | |
Text
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t UNITED STATES g
j NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 2008H001 l
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.216 AND 93 TO FACILITY OPERATING LICENSE NOS. DPR-66 AND NPF-73 DUQUESNE LIGHT COMPANY l
OHIO EDISON COMPANY PENNSYLVANIA POWER COMPANY i
THE CLEVELAND ELECTRIC ILLUMINATING COMPANY THE TOLEDO EDISON COMPANY BEAVER VALLEY POWER STATION. UNIT NOS.1 AND 2 DOCKET NOS. 50-334 AND 50-412
1.0 INTRODUCTION
By [[letter::L-98-127, LARs 256 & 126 to Licenses DPR-66 & NPF-73,modifying Channel Calibr Definition to Exclude RTDs & Thermocouples from TS Channel Calibr Requirements|letter dated June 19,1998]], as supplemented June 23,1998, the Duquesne Light Company (the licensee) submitted a request for changes to the Beaver Valley Power Station, Unit Nos.1 and 2 (BVPS 1 and BVPS-2), Technical Specifications (TSs). The requested changes would rev;se the BVPS-1 and BVPS-2 TSs definitions of a channel calibration to add two sentences stating that (1) the calibration of instrument channels with resistance temperature detector (RTD) or thermocouple (T/C) sensors may consist of an inplace qualitative assessment of sensor behavior and normal calibration of the remaining adjustable devices in the channel and (2) whenever a sensing element is replaced, the next required channel calibration shallinclude an inplace cross calibration that compares the other sensing elements with the recently installed sensing element. This change wouid make the BVPS-1 and BVPS-2 TS definition of channel calibration consistent with the definition of a channel calibration contained in the NRC's improved Standard Technical Specifications for Westinghouse Plants (NUREG-1431, Revision 1). The June 23,1998, letter provided minor editorial changes to the TS pages that did not change the initial proposed no significant hazards consideration determination or expand the amendment request beyond the scope of the June 26,1998 Federal Reaister notice.
2.0 EVALUATION The current BVPS-1 and BVPS-2 TS definition of channel calibration (TS 1.19) is as follows:
CHANNEL CALIBRATION 1.9 A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the channel output such that it responds with the necessary range and accuracy to known values of the parameter which the channel monitors. The CHANNEL 9807310077 980728 PDR ADOCK 05000334 P
2 CALIBRATION shall encompass the entire channel including the sensor and alarm and/or trip functions, and shall include the CHANNEL FUNCTIONAL TEST. The l-CHANNEL CALIBRATION may be performed by any series of sequential, overlapping or total channel steps such that the entire channel is calibrated.
This definition requires that a channel calibration of instrument channels containing RTD or T/C l
sensors shallinclude these sensors. Duquesne Light Company (DLC) proposed that the current definition be revised to better account for standard industry methodology for temperature sensor channel calibration. The proposed revision would make the definition of channel calibration read
- as follows:
CHANNEL CALIBRATION 1.9 A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the channel output such that it responds with the necessary range and accuracy to known values of the parameter which the channel monitors. The CHANNEL CALIBRATION shall encompass the entire channel, including the sensor and alarm l
and/or trip functions, and shall include the CHANNEL FUNCTIONAL TEST, Calibration of instrument channels with resistance temperature detector (RTD) or thermocouple sensors may consist ofinplace qualitative assessment of sensor behavior and normal calibration of the remaining adjustable devices in the channel.
Whenever a sensing element is replaced, the next required CHANNEL CALIBRATION shall include an inplace cross calibration that compares the other sensing elements with the recently installed sensing element. The CHANNEL t
CALIBRATION may be performed by any series of sequential, overlapping or total channel steps such that the entire channelis calibrated.
DLC stated that removal and installation of RTDs, and T/Cs, solely for the purpose of calibration could introduce errors, cause sensor damage, and increase personnel occupational radiation exposure since most of these sensors are locatert in systems containing radioactive fluid. DLC further stated that in order to confirm the calibration of instrument channels having RTD or T/C temperature sensors, DLC will perform inplace qualitative assessments of sensor behavior. The reactor coolant system RTDs have been cross calibrated in accordance with current procedures and within the frequencies required by TSs. Qualitative assessments of sensor behavior of other TS required temperature sensors will be completed prior to changing modes from the present plant operating mode (Mode 5). Subsequent RTD and T/C qualitative assessments will be performed consistent with the frequency specified in the current TSs. If calibration of a temperature sensor is confirmed by inplace qualitative assessment using cross calibration, and if that temperature sensor must be replaced, the next required channel calibration will include an inplace cross calibration which compares the similarly located sensing elements with the recently installed sensing element. The proposed revision to TS 1.g (definition of channel calibration) includes these cross calibration and assessment requirements.
The issue of cross calibration was addressed in NUREG/CR-5560, " Aging of Nuclear Plant Resistance Temperature Detectors," which recognizes that on-line cross calibration can be a reasonable method for temperature sensor calibration. However, as stated in NUREG/CR-5560, to perform in-situ calibration would normally require one or more newly calibrated sensors to be used as a reference. Without a reference, the cross calibration will not account for common i
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i mode (systematic) drift and will only provide information on the consistency and not the accuracy of the installed sensors. The cross calibration technique assumes that the average of the sensor measurements represents the true process temperature and that sensor drift is random and not systematic. The results of studies referenced in NUREG/CR-5560 indicate that sensor drift is usually random. However, the particular testing done to validate the cross calibration methodology in NUREG/CR-5560 utilized newly calibrated sensors for the test.
The inplace cross calibration of temperature sensors is an acceptable method of performing a qualitative assessment of these sensors' behavior as delineated in Branch Technical Position HICB-13, " Guidance on Cross Calibration of Protection System Resistance Temperature Detectors," Revision 4, June 1997, of the NRC's Standard Review Plan.
The NRC staff also notes that DLC's proposed change in TS 1.9 (definition of channel calibration) is consistent with the definition of channel calibration presented in the NRC's improved Standard Technical Specifications for Westinghouse Plants (NUREG-1431, Revision 1).
Based on the foregoing, the NRC staff agrees with the proposed change to the definition of channel calibration and finds it acceptable.
The changes noted in DLC's June 23,1998, letter are purely administrative in nature and do not change any requirements in the TSs, and are therefore, acceptable.
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Pennsylvania State official was notified 6f the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in t
l ihe 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 amendments involve no significant hazards consideration, and there has been no public comment on such finding (63 FR 34939). Accordingly, the amendments meet 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 connection with the issuance of the amendments.
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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 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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Donald S. Brinkman Date: July 28, 1998 i