ML20070Q235
| ML20070Q235 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 01/03/1983 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20070Q187 | List: |
| References | |
| NUDOCS 8301260448 | |
| Download: ML20070Q235 (2) | |
Text
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GPU Nuclear UC GM P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:
January 3, 1983 Mr. Thomas T. Martin, Director Division of Engineering and Technical Programs U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Dear Mr. Martin:
Subj ect: Oyster Creek Nuclear Generating Station Docket No. 50-219 IE Inspection No. 82-23 In accordance with 1G CFR 2.201, the attachment to this letter provides our responce to Violation B of the Notice of Violation contained in your letter of November 18, 1982. Our response to Violation A was forwarded by our letter dated December 21, 1982. An extension of this response was requested by GPU Nuclear December 20, 1982, and granted by NRC Region I on the same day during a telecon with Mr. Todd Jackson.
If there are any questions, please contact me or Mr. Michael Laggart of my staf f at (609) 971-4643.
Very truly yours, C
N Peter B. Fiedler Vice President and Dire; tor Oyster Creek PBF:MWL:ja1 At tachment cc:
Mr. Ronald C. Haynes, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 NRC Resident In spect or Oyst er Creek Nuclear Generating Station Forked River, NJ 08731 8301260448 830121 PDR ADOCK 05000219 G
PDR GPU Nuclear is a part of the General Pubhc Utikties System
O ATTACRKENT Violation B Monitoring Requirements of Section 2.0 of the Oyster Creek Environmental Technical Specifications (OCETS) requires that the thermal monitoring system be calib ra ted.
Section 1.0 of tha OCETS defines calibration to encompass all aspects of the circuit, including the sensor, indicating control features, alarm, and/or trip functions.
Contrary to the above, as of September 17, 1982, the periodic routine thermal monitoring system calibrations performed since July 1981 did not include calibration of the integrated system including the thermal sensor (RTD).
Re s pons e The violation is correct in that calibration being performed did not include the thermal sensors, but rather only encompassed the circuit f rom the sensor to the instrumentation in the control room.
The instrumentation being utilized as sensors are Resistance Temperature Detectors (RTD). Based on manufacturer's documentation and field application experience, accuracy drif t is not inherent in these devices. Failure of an RTD would be indicated by gross upscale or downscale indication. Our choice in providing such an accurate and reliable sensor was predicated on the degree of accuracy needed for this application.
Although the calibrations which were performed did not include the thermal sensors, based upon the manufacturer's documentation and field application experience with the type of sensor utilized, we feel confident that the thermal monitoring system has been providing accurate temperature indication which meet the objectives of our Technical Specification monitoring requirements.
The thermal monitoring system contains redundant sensors at three separate remote locations. An accurate method of full range in-situ calibration of the sensors is not practicable at this time.
In-situ calibration of these sensors over the full range poses not only practical problems of providing a calibration medium over a range of 200F to 120 F in the field, but also poses certain personnel saf ety and environmental concerns. This is particularly evident at the U.S. Route 9 bridge location where personnel must perform the calibration while standing on an unused railroad tressel directly over the Oyster Creek discharge canal. Performing a calibration at such a precarious location, especially during the inclement weather of ten experienced during the winter months, presents certain safety hazards to our personnel. Also, to l
cond uc t the calibration requires removing the sensor from an approximately 10 foot long tube which is filled with oil to protect the sensor cable. The additional activity associated with calibrating the sensor, as opposed to replacement with a precalibrated sensor, adds increased risk of inadvertently spilling this oil into the discharge canal. In order to comply with the calibration requirements for these six (6) sensors, we plan to replace each sensor on a monthly basis during plant operation wi h a vendor calibrated RTD.
t The replacement will be done concurrent with conducting the monthly system calib ra t ion.
Replacement with a vendor calibrated sensor concurrent uith calibration of the remainder of the circuit by station personnel will constitute calibration of all aspects of the circuit, consistent with the requirements of the OCETS. Additional sensors have been ordered to isolement this program and delivery is expected within six (6) weeks. The replacement program will be implemented within thirty days af ter receiving the spare monitors. At this time, full compliance will be achieved.