ML20077E058
| ML20077E058 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 12/06/1994 |
| From: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 94-668, NUDOCS 9412120081 | |
| Download: ML20077E058 (5) | |
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l VIHOINIA ELEcrHrc AND POWEH COMPANY usennoxn,Vnuosuns uncan December 6,1994 U. S. Nuclear Regulatory Commission Serial No.94-668 Attention: Document Control Desk NAPS /JHllEJW R9 Washington, D. C. 20555 Docket Nos.
50-338 License Nos.
NPF-4 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 1 INSPECTION REPORT NOS. 50-338/94-22 AND 50-339/94-22 REPLY TO A NOTICE OF VIOLATION We have reviewed your letter of November 7,1994, which referred to the inspection conducted at North Anna Power Station from September 18,1994 to October 15, 1994, and the associated Notice of Violation which was reported in Inspection Report i
Nos. 50-338/94-22 and 50-339/94-22. Our reply to the Notice of Violation is attached.
In your letter, you stated that the violation was of concern because it was NRC's view that sufficient information was available during the operating cycle to question the resistance temperature detector installations. As noted in the NRC's inspection report, Virginia Power did evaluate the condition of the resistance temperature detectors (RTDs) during the operating cycle. However, in light of the as found condition of the RTDs.during the last Unit 1 outage, our evaluation should have been more questioning.
If you have any further questions, please contact us.
Very truly yours, James P. O'Hanlon Senior Vice President - Nuclear Attachment 0$d212 guck 05000:3s oal 941206 g
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PDR v
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l lb. S. Nuclear Regulatory Commission cc:
Region ll 101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. R. D. McWhorter NRC Senior Resident inspector North Anna Power Station
REPLY TO A-NOTICE OF VIOLATION INSPECTION REPORT NOS. 50-338/94-22 AND 50-339/94-22 NRC COMMENT During an NRC inspection conducted from September 18 through October 15,1994, a violation of NRC requirements was identified.
In accordance with the " General Statement of Policy and Procedure for NRC Enforcement Actions," 10 CFR Part 2, Appendix C, the violation is listed below:
10 CFR 50.49 requires that programs be established for environmentally qualifying electric equipment including post accident monitoring equipment.
This requirement is implemented by Virginia Power Administrative Procedure (VPAP) 0305, Electrical Equipment Oualification Program. VPAP-0305, Section 6.3.1.a, requires controls to ensure environmentally qualified equipment be maintained in its qualified state through its qualified life during maintenance, installation, and replacement. Technical Specification Table 3.3-10 identifies the reactor coolant wide range temperature instrumentation as accident monitoring instrumentation.
Contrary to the above, from April 10,1993 to September 9,1994, Unit 1 reactor coolant wide range temperature instrumentation was not maintained in its designed qualified state. Specifically, insulation that was designed to protect the wide range temperature instrumentation from reactor coolant system heat was not appropriately configured. The insulation's absence caused an adverse temperature environment which allowed the instruments to exceed conditions used for their qualification basis.
This is a Severity Level IV Violation (Supplement 1).
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REPLY TO A NOTICE OF VIOLATION 1.
REASON FOR THE VIOLATION The violation was caused by inadequate installation of thermal insulation around the Reactor Coolant System pipe and thermowell containing the wide range Resistance Temperature Detectors (RTDs). The improperly configured thermal insulation allowed the RTDs to experience elevated temperatures that were outside their environmental qualification (EO) design basis during the previous operating cycle. A review of the insulation installation practices determined that the violation was caused by a dependence on skill of the craft
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for installation and inadequate instructions for certain applications of insulation.
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CORRECTIVE STEPS WHICH HAVE BEEN TAKEN AND THE RESULTS ACHIEVED During the 1994 Unit 1_ refueling outage, the wide range RTDs were replaced with headless RTDs. Insulation was installed around the RTD's thermowell to improve isolation of the RTD from the heat source.
Instrument maintenance procedures for replacement of RTDs were revised to add steps to verify that RTD insulation is properly installed. Steps were added to the instrument maintenance valve lineup procedures to verify installation of RTD insulation.
Current RTD insulation practices were reviewed and recommendations for improvement have been approved by management for implementation. The recommended improvements include conducting a walkdown of each RTD prior to removal of existing insulation to ensure design compatibility, designing an insulation application for each RCS RTD, providing installation, inspection and procedural requirements, and including post installation acceptance criteria.
Utilizing the vendor's (Weed) methodology, an engineering evaluation was performed to determine the qualified life and operability of the North Anna 1 and 2 RCS wide range RTDs. The evaluation determined that the Unit 2 wide range RTDs are qualified through the current operating cycle and that the affected Unit 1 RTDs were considered operable during the previous operating cycle.
The previous operating cycle for Unit 1 ended September 9,1994.
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' 3. : ' CORRECTIVE STEPS WHICH WILL BE TAKEN TO AVOID FURTHER VIOLATIONS As a precautionary measure, the Unit 2 wide range RTDs,2-RC-TE-2413 and 2-RC-TE-2423, will be replaced during the 1995 Unit 2 steam generator replacement / refueling outage which is scheduled to start on March 25,1995.
The approved recommendations associated with RTD insulation installation practices will be implemented, as appropriate, prior to completion of the next refueling outages. The recommendations are described in the preceeding section. Currently the next Unit 1 refueling outage is scheduled to start on February 5,'1996, and the next Unit 2 refueling outage is scheduled to start on March 25,1995.
A procedure will be developed for installation of thermocouples that monitor the RCS RTDs prior to the upcoming Unit 2 refueling outage.
4.
THE DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED Full compliance was achieved when the Unit 1 wide range hot leg RTDs were replaced and insulation was installed during the Unit 1 1994 refueling outage.
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