ML20046B536
| ML20046B536 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 07/26/1993 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NSD930884, NUDOCS 9308050078 | |
| Download: ML20046B536 (2) | |
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GENERAL OFFICE
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9 P.O. BOX 499. COLUMBUS, NEBRASKA 68602-0439 Q] Nebraska Public Power District "T&"S'Es%*
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NSD930884 July 26, 1993 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 Gentlemen:
Subj ec t :
NPPD Response to Inspection Report 50-298/93-20 (Reply to Notice of Violation)
This letter is written i t. response to your letter dated June 29, 1993, which transmitted a Notice of Violation (NRC Inspection Report No. 50-298/93-20).
Following is the statement of violation and our response in accordance with 10 CFR 2.201.
STATEMENT OF VIDIATION Technical Specification 6.3.2.C requires that written procedures and instructions including applicable checkoff lists shall be established, implemented, and maintained for emergency conditior< involving possible or actual releases of radioactive materials. Criterion V of Appendix B,10 CFR Part 50, " Instructions, Procedures, and Drawings," specifies, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
One example of violating this requirement is stated below.
Emergency Plan Implementing Procedure 5.7.16,
" Release Rate Determination," specifies the process to determine airborne radioactive release rates under plant emergency conditions.
Contrary to the above, Emergency Plan Implementing Procedure 5.7.16, Revision 16, implemented on May 7,
1993, was inappropriate to the circumstances because it contained erroneous instructions for determining the noble gas release rates using the primary containment monitor and the drywell curie content in Steps 8.3.5, 8.4.5, and Attachments 3 and 4.
The licensee had created, then failed to identify, the error during the procedure revision process.
This is a Severity Level IV violation (298/9320-01) (Supplement VIII).
REASON FOR VIO1ATION In an effort to improve the effectiveness of plant procedures, human factors improvements have been made to Emergency Plan Implementing Procedures (EPIP) attachments as procedure revisions are processed.
During the processing of Revision 16 to EPIP 5.7.16, human factors changes in the procedure were made that 9308050078 930726
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Document Control Desk July 26, 1993 Page 2 introduced errors into the mathematical formulae in the attachment to EPIP 5.7.16 f or noble gas release rate determination. Specifically, in revising Steps 8.3.5 and 8.4.5 from their word text format in Revision 15 to a mathematical formula, various terms were incorrectly assigned to the denominator of the formula that should have been in the numerator.
These errors produced non-conservative results. The errors were not discovered by the reviewers since the intent of the revision, as initiated, was not to change these calculations. During the review, the attachments in EPIP 5.7.16 Revision 16 were compared against the body of the procedure for proper computational sequence.
However, no sample calculations were made using the attachments to verify the attachments still yielded the expected results.
In addition, it was not noted that the erroneous formulae resulted in incorrect units of measurement for the parameter being determined.
During the timeframe the erroneous procedure was in effect (May 7-26, 1993) the plant was shutdown for a refueling and maintenance outage.
CORRECTIVE STEPS TAKEN AND RESULTS ACHIEVED The errors in the procedure were initially discovered on May 18, 1993 by a Health Physicist from the Kansas Department of Health and Environment who described the letter received by NPPD on May 24, 1993.
A Procedure Editorial errors in a Change was initiated and the corrected procedure was issued on May 26, 1993.
Mathematical computations in other EPIPs were reviewed to verify that similar errors had not been introduced by the human factors improvement efforts. None were found.
CORRECTIVE STEPS WHICH WILL BE TAKEN TO AVOID FURTHER VIOLATIONS CNS Procedure 0.4,
" Procedure Change Process," will be revised to ensure all procedure revisions that involve calculations important to nuclear safety or personnel safety, are verified to assure that the results have not been unexpected!y changed.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED The procedure change will be implemented by October, 1993.
Shou,1d you have any questions concerning this matter, please contact my office.
Sir ere1y,
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G.fRgHorn Nu'elear Power Group Manager
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Regional Administrator USNRC - Region IV NRC Resident Inspector Cooper Nuclear Station
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