ML20216A995
| ML20216A995 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 05/07/1998 |
| From: | Laux J UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-483-98-11, ULNRC-3809, NUDOCS 9805140330 | |
| Download: ML20216A995 (6) | |
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Union Elsctric Po Box 620 collaway aant Fulton, MO 65251 May 7,1998 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop PI-137 Wash:.gton, DC 20555-0001 ULNRC-3809 Gentlemen:
MI6 SUPPLEMENTAL RESPONSE TO NOTICE OF VIOLATION pyj N
INSPECTION REPORT NO. 50-483/97011 UE CALuwAv PtANr UNION ELECTRIC CO, Ref
- 1) Inspection Report 50-483/97011, dated December 24,1997
- 2) ULNRC-3709, dated February 6,1998.
This responds to Mr. Arthur T. Ilowell's letter dated April 8,1998. That letter requested additional information be provided to supple. :nt our presious response to the Notice of Violation for events discussed in Inspection Report 50-483/97011. Our response to the concerns identified in your letter is presented in the attachment.
None of the material in the response is considered proprietary by Union Electric.
If you have any questions regarding this response, or if additional information is required, please let me know.
Very truly yours, J. V. Laux Manager, Quality Assurance JVL/tmw I
Attachment:
- 1) Supplemental Response to Violation
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9E05140330 980507 PDR ADOCK 05000483 0
PDR a subsidiary el Amorea Corporation
ULNRC-3809
'May 7,1998 Page 2 cc: Mr. Ellis W. Merschoff Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Dr. Dale A. Powers Chief, Maintenance Branch, DRS U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Senior Resident Inspector Callaway Resident Oflice U.S. Nuclear Regulatory Conunission 8201 NRC Road Steedman, MO 65077 Ms. Kristine M. Thomas (2 copies)
Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Conunission Mail Stop 13E16 Washington, DC 20555-2738 Manager, Electric Department Missouri Public Service Commission i
PO Box 360 Jefferson City, MO 65102 Mr. Thomas A. Baxter Shaw, Pittman, Potts, & Trowbridge 2300 N. Street N.W.
Washington, DC 20037 Manager, Plant Support Wolf Creek Nuclear Operating Corporation PO Box 411 Burlington, KS 66839
At*chment to UL; '.U-3809 May 7,1998 Page1 Statement of Violation A In regard to your response to Example 1, additional information regarding the planned change to the performance criteria, for the containment Isolation function is needed in order to evaluate the effectiveness of the corrective actions. Specifically, we request that you provide the definition of" failure" which is referred to in Item 2 of the planned changes to the performance criteria on page 5 ofyour response. As presently stated, simultaneous failures of both valves in a penetration could be interpreted to mean: both valves of a penetration exceeding their individual administrative leakage limits; both valves, as well as, eight other valves exceeding their administrative leakage limits; or both valves exceeding 0.4 L. Please explain simultaneous failure of both valves in a penetration with regard to test program leakage.
In regard to your response to Example 2, you did not agree that a violation had occurred in your monitoring of feedwater heaters. We agree with your position that the feedwater heaters are not classi6ed as run to-failure and are presently being monitored at the plant level. We also recognize that a design change to replace the feedwater heater tube bundles with an improved design is in progress. However, additional inforn ation is needed before we can further consider you denial of this portion of Violation A, Example 2. Specifically, have there been, or could there be, occasions where tube failures have been repaired without incurring a power loss? In addition, how will your plant-level performance criteria recognize ud capture degraded heater performance using unplanned capacity loss when there is an wisting reduced power level for core axial offset, or any other reason?
In regard to your response to Example 2 that addressed heater drain pump seals, the planned corrective action to evaluate the heater drain pump seals for monitoring in a rim-to-failure mode is satisfactory. We will verify the implementation of your planned corrective action during future inspection activities at the Callaway site.
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I g Attachment to ULNRC-3809 May 7,1998 Page 2 l
Sunnlemental Response to Violation A Examplel The simultaneous failure of both valves in a penetration is the failure ofboth valves to
- activate upon a valid Containment Isolation Signal for any reason. The basis for this performance criterion is that the simultaneous failure of both valves in a single penetration could result in an uncontrolled release from the Containment. Performance Criteria #1 and
- 4 provide the assurance that the leakage through the containment penetrations is at an acceptably low level.
Performance Criterion #2 for the containment isolation function will be clarified as i
follows:
- 2. No simultaneous failure to activate on a valid Containment Isolation System of both the inside and outside valves in a single penetration.
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This.evised criteria will be implemented by April 30,1998.
Example 2 Callaway experienced two instances oflow pressure feedwater heater tube failures in the l
current operating cycle (Cycle 9). These did not result in a load reduction since Callaway L
was operating at a reduced power level due to the core axial offset anomaly. In each case a corrective action document (SOS) was initiated per the requirements of Procedure APA-ZZ-00500, Corrective Action Program. The two SOS's were evaluated for Functional Failures per the requirements of the Callaway Maintenance Rule Program. The low pressure feedwater heaters are also monitored under the plant level performance criteria of unplanned reactor trips. Monitoring of the low pressure feedwater heaters for functional failures and unplanned reactor trips ensures that tube failures are not masked.
Therefore, the low pressure feedwater heaters are adequately being monitored per the requirements of 10 CFR 50.65.
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a Attachment to ULNRC-3809 May 7,1998 Page 3 Statement of Violation B In regard to your response to Violation B, we note that you intend to review all suggestion occurrence solution reports that have been initiated since July 10,1993, in order to verify that all structures, systems, or components (SSCs) within the program scope have been properly evaluated and classified as Category (a)(1) or (a)(2). This corrective action is satisfactory and will be reviewed during a future inspection. However, we request clarification on your completed corrective action. In particular, the team noted in the inspection report that a failure would not be classified as a functional tailure on the basis that an equipment operator was available at the valve to open it and that personnel errors during the performance of maintenance activities were not considered for functional failure evaluations. As a result of your response to Violation C, please discuss your current position relative to taking credit for operator intervention for functional failure evaluation. Also, please describe how your program evaluates personnel errors in determining whether functional failures have occurred.
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I Supplemental Response to Violation B The Maintenance Rule Program at Callaway evaluates an event to first determine if a functional failure occurred. If a function of an SSC within the scope of the Maintenance Rule at Callaway is lost, when it is required, then a functional failure has occurred. The evaluation for Maintenance Rule functional failures does not consider the cause of the event. The cause could be the result of equipment failure or human performance error. No credit is taken for operator intervention in the case of functional failures. Even if an operator were present and could easily remedy the loss of SSC function after the event has begun, Callaway would consider the event to be a functional failure.
Attachment to ULNRC-3809 May 7,1998 Page 4 Statement of Violation C In regard to your response that provides train unavailability criteria for monitoring the reactor protection trip system, we find the planned corrective action to be acceptable. We will review the implementation of the corrective action during a future inspection.
Your planned program change concerning the evaluation of unavailability does not take into consideration the unavailability of risk-significant SSCs during surveillance if there is a minimal restoration time for those SSCs and is, therefore, not acceptable because this action would not necessarily preclude future violations. Your reference to INPO performance indicator reporting guidelines for taking credit for operator action to quickly restore SSCs undergoing surveillance is not endorsed by NRC. NUMARC 93-01 guidance, which is endorsed by NRC, is clear with respect to availability determination in that SSCs, which respond automatically, must be subject to direct control or function automatically without human action to be considered available. Your approach does not take into consideration that maintenance / surveillance time be counted as unavailable for the purpose of determining the effectiveness of the maintenance and surveillance j
performed on SSCs. Furthermore, your stated intention to take exception to the guidance of NUMARC 93-01 for availability determination, by allowing a " minimal" Intervention time, was not accompanied by an acceptable alternative for NRC review.
Sunnlemental Response to Violation C Callaway will revise our Maintenance Rule Program to require the monitoring of unavailability of risk significant SSC's during surveillance testing when the system or train is not available for automatic operation. This monitoring will begin in Cycle 10, currently 2
scheduled to begin in May 1998. Since the current performance criteria did not take this l
into account, the performance criteria will be revised to account for this additional out-of-service time that is not accounted for in the Callaway IPE. Revisions to the performance criteria will be completed by June 30,1998.
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