ML20041C693
| ML20041C693 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/24/1982 |
| From: | Leasburg R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0588, RTR-NUREG-0809, RTR-NUREG-588, RTR-NUREG-809 105, IEB-79-01B, IEB-79-1B, NUDOCS 8203020471 | |
| Download: ML20041C693 (2) | |
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February 24, 1982
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Mr. Harold R. Denton, Director Serial No. 105 Office of Nuclear Reactor Regulation N0/RGS:Ims Attn:
Mr. Robert A. Clark, Chief Docket Nos. 50-338 Operating Reactors Branch No. 3 50-339 Division of Licensing License Nos. NPF-4 U. S. Nuclear Regulatory Commission NPF-7 Washington, D. C.
20555 Gentlemen:
REVISION TO LICENSE CONDITION AND ENVIRONMENTAL QUALIFICATION COMMITMENT RESISTANCE TEMPERATURE DETECTORS (RTD'S)
I.E. BULLETIN 79-01B AND NUREG 0588 NORTH ANNA UNITS 1 AND 2 The purpose of this letter is to inform you of our intentions concerning the replacement of resistance temperature detectors (RTD's) at North Anna Units 1 and 2.
The matter of RTD replacement has been addressed in license condition 2.C.(4)(c) for Unit 2 which states that, "No later than June 30, 1982, the wide-range resistance temperature detectors for the reactor coolant system shall be qualified for radiation exposure for the 40 year plant life and appropriate exposure condition due to design basis accidents.
Pending comp-letion of such qualification and acceptance by the Commission, VEPC0 shall replace each of these detectors at each refueling outage."
In addition, our letter Serial No. 330 dated August 24, 1981 for Unit 1 and letter Serial No.
355 dated September 4,1981 for Unit 2 provided our response regarding RTD replacement to your Safety Evaluation Report for environmental qualification of safety-related electrical equipment.
In the license condition for Unit 2 and our commitments on environmental qualification for both units, Vepco committed to replace the RTD's during each refueling outage until a long-term qualified RTD is available.
Vepco has received equipment bid proposals from several RTD vendors that indicate environmental qualification requirements of IEEE 323-1974 are met by their products.
We are encouraged by the equipment qualification documenta-tion that we have received from one vendor.
However, several items must be resolved before we can confirm that the RTD is qualified and can be installed at North Anna.
O B203020471 820224 L
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DR ADOCK 05000338 PDR
Vs wom A EllCThlC AND Powth COMPANY TO 2
Recently the Electric Power Research Institute (EPRI) developed an accurate method (<10% error) for measuring RTD time response called the Loop Current Step Response (LCSR) method.
We have tested, Analysis and Measurement Services Corporation (AMS) test equipment, the LCSR method and found it to be a viable method for obtaining reasonably accurate results.
In addition, it is our understanding that the NRC, (NUREG-0809 dated August 1981) has reviewed the AMS LCSR methodology and finds it to be reliable and adequate to measure the RTD time constant and time response.
Based on the above discussion on the improved accuracy of RTD time response testing, Vepco intends to test (LCSR method) the Reactor Coolant System (RCS) Narrow and Wide Range RTD's in Units 1 and 2 each quarter until a long-term qualified RTD is available. We do not intend to replace the RCS RTD' r during the Spring 1982 refueling outages, unless we acquire unsatisfactory LCSR test results on individual Rosemount RTD's.
We feel that this is a reasonable approach based on the results of the NRC and EPRI studies.
Therefore, we request your review and approval of the approach we have outlined for interium action with regard to the environmental qualification requirements for the RTD's.
We are available at your earliest convenience should additional information be required.
Very truly you s,
/
R. H. Leasburg cc:
Mr. Richard C. DeYoung, Director NRC Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D. C.
20555 Mr. James P. O'Reilly, Regional Administrator Office of Inspection and Enforcement l
Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 1
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