BSEP-93-0042, Responds to NRC Re Violations Noted in Insp Repts 50-324/93-02 & 50-325/93-02.Corrective Actions:Corrosion Preventive Program Will Be Integrated W/Insp Procedures to Ensure Resolution of Identified Corrosion
| ML20035D235 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 04/05/1993 |
| From: | Richard Anderson CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BSEP-93-0042, BSEP-93-42, NUDOCS 9304120309 | |
| Download: ML20035D235 (6) | |
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Carolina Power & Light Company Enmswick Stream Electric Plant P.O. Ilox 10429 i
Southport, North Carolina 28461 APR 051993 i
SERIAL: BSEP-93-0042 United States Nuclear Regulatory Commission ATTENTION: Document Contrcl Desk Washington, DC -20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2
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DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 REPLY TO NOllCE OF VIOLATION i
Gentlemen:
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On March 4,1993, the Nuclear Regulatory Commission issued a Notice of Violation for the Brunswick Steam Electric Plant. Units 1 and 2. Details of the underlying NRC inspections are provided in Inspection Report Nos. 50-325/93-02 and 50-324/93-02 dated March 4,1993.
Carolina Power & Light Company hereby responds to the Notice of Violation. Enclosure 1 to this letter provides CP&L's reply to the Notice of Violation in accordance with the provisions of 10 CFR 2.201.
Please refer any questions regarding this submittal to Mr. R. C. Godley at 1919) 457-2412.
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GMT/gmt Enclosures cc:
Mr. S. D. Ebneter Mr. P. D. Milano Mr. R. L. Prevatte I
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ENCLOSURE 1 j
i BRUNSWICK STEAM F 'CTRIC PLANT, UNITS 1 AND 2 NRC DONF t 3S. 50-325 & 50-324 OPERATINC _.itNSE NOS. DPR-71 & DPR-62 l
REPLY TO NOliCE OF VIOLATION l
VIOLATION:
During an NRC inspection conducted on January 11 - February 12,1993, 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-l l
Technical Specification 6.8.1 requires that written procedures be established, implemented, j
and maintained for applicable procedures recommended in Appendix A of Regulatory Guide 1.33, November 1972. Appendix A to Regulatory Guide 1.33 requires in part that specific procedures for surveillance tests, inspections and calibrations be wntten and implemented for each surveillance test, inspection or calibration required by the Technical Specif:ations.
Carolina Power & Light Company Periodic Test procedure PT-20.5.1, Primary Containment inspection, was written to provide requirementr for visualinspections of the containment structure which are performed to meet Technical Specifications 4.6_1.4.1 and 4.6.2.1.e.1.
Paragraph VI.C.2 of PT 20.5. requires that indications (rust stains or corrosion) be measured, sketched and described on the procedure data sheets. Paragraph 11 of procedure PT 20.5.1 requires the indications to be evaluated per ENP-12.
Contrary to the above, the depth and extent of corrosion of the drywell liner plate at the intersection of the interior concrete floor and interior drywellliner plate a~ound the entire circumference of the drywell was not measured or evaluated when the inspections were performed in 1987,1989,1990, and 1991 in toe Unit 1 drywell and in 1988.1990,and 1991 in the Unit 2 drywell.
This is a Severity Level 8V violation (Supplement 1).
j RESPONSE TO VIOLATION:
A.
Admission of Violation:
Carolina Power & Light Company admits this violation.
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B.
Reason for Violation The violation cites various dates for inspections when extent of the corrosion was not measured or evaluated. The dates listed are not entirely correct, however. For Unit 1 in 1989 inon-ILRT outage) and 1990, no drywell liner inspections were scheduled and thus I
were not performed. For the Unit 1 and 2 inspections performed in 1991, evaluations were i
not performed based on the procedures listed acceptance criteria. Evaluation of the '
f remaining inspections were performed but were inade7uate in that the depth and extent of the corrosion was not fully documented by the inspections such that a valid evaluation
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could be conducted. The Unit 21992 liner inspection that was on-going had documented an increase in liner corrosion that would have required an evaluation, but the ability to identify the increase was aided by the inspector's previous involvement in the 1988 liner inspection.
l The visualinspections conducted of the interior surfaces of the drywellliner during the series of Periodic Terts (pts), PT-20.5.1 (Primary Containment inspection), lacked sufficient guidance to establish a meaningful baseline for the liner corrosion. T he procedure did not l
give a method to allow for nor give guidance for tracking corrosion growth rate over a period of time. Without this guidance the results from subsequent evaluations could not adequately build on the previous findings. Also, the Acceptance Cotena were wntten such that previous corrosion findings were required to be revisited. However, if thcre was a l
previous Engineering Evaluation Report the acceptance criteria could be interpreted to mean
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additional evaluations were not required.
Managerial standards for material condition corrosion issues were low. Plant personnel did not have the general guidance needed to determine what level of corrosion was acceptable l
l and at what point additional / corrective action would be required. This was reflected in the I
subjective wording used in the procedure, like " badly corroded" that could have different meanings for different inspectors. This resulted in the inspectors not providing sketches of i
the deficient areas as the procedure intended.
i C.
Corrective Actions. Steps Taken, and Result Achieved Special Procedure OSP-93-010, Drywell Liner Corrosion Examination, was developed to quantify the extent and depth of the liner corrosion (see Attachment 1). The procedure provides instructions for cleaning the liner plate, designation of inspection zones, and instructions for measuor.g the base metal plate thickness and the depth of pits m the corroded areas. The plate thickness is measured using Ultrasonic Testing (UT) methods in unaffected areas adjacent to the corrodc t area. The depth of corrosion is measured using dental molding compound.
The examir"31 ion of the Unit 2 liner determined that five areas required base metal repairs to restore the liner plate to an acceptable thickness, and these repairs are complete. United Engineers and Constructors has prepared a calculation to document the as-found condition of the liner and determined the liner to be operable with the corroded areas. The onginal UFSAR assumption that the liner yields before it buckles remains vahd. The minimum E1-2
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acceptance criteria for liner thickness and repair evaluation are documented in Engineering Evaluation Report (EER) 93-0173 revision 2. To minimize recurring corrosion, this area of the liner was recoated with an epoxy coating and an enhanced seal was installed in the expansion joint between the liner plate and the concrete floor that will prevent the liner from contacting the shallow standing water present in this area (see Attachment 2). This same process will be used for Unit 1, with the inspections and repairs (if required) being performed prior to the restart of Unit 1.
Other procedures used by Technical Support were reviewed for non-specific or subjective acceptance criteria, procedure wording, or guidance. This review identified 18 procedures that require enhancement.
D.
Corrective Actions That Will be Taken to Avoid Future Violations The acceptance criteria of PT-20.5.1 will be revised by September 1993 to clarify the requirements for evaluation of previously analyzed indications. The revision will also provide inspectors sufficient detail and guidance for proper inspections.
This event will be reviewed May 10,1993, with appropriate Technical Support personnel emphasizing the need to ensure acceptance critena for surveillance testing is satisfied and that identified concerns are addressed.
The 18 Technical Support procedures needing enhancement due to non-specific or subjective wording will be revised by September 1993.
The Brunswick Nuclear Plant Three Year Plan, submitted to the NRC Decernber 15,1992 includes a Corrosion Controlinitiative (# 502). This initiative is part of a broader focus area that aims to improve system reliability and material condition. The objective of the Corrosion Control initiative is to: Provide preventive measures to control the effects of corrosion at the cosmetic stage and well before structural integrity is challenged. Provide corrective measures to restore existing equipment and structures affected by corrosion"(sic). This initiative will develop a comprehensive program to address root causes of existing corrosion, implement preventive maintenance measures, provide repairs for existing corroded equipment and structures, and upgrade materials and coatings where appropriate. This corrosion prevention program will be integrated with inspection procedures such as PT 20.5.1 to ensure resolution of identified corrosion concerns by qualified inspectors and engineers.
Also efforts are being taken to minimize corrosion in the drywells and torus with a project i
to refurbish coatings. A schedule for this work will be provided tu the NHC by June 30.
1993.
E.
Date of Full Comphance CP&L will be in full compliance upon completion of the Unit 1 drywell liner inspection, which w:ll be I
performed prior to the Unit 1 Startup.
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