GO2-05-065, Review of NRC Violation 50-397/04-05-02
| ML051090295 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 04/04/2005 |
| From: | Atkinson D Energy Northwest |
| To: | Document Control Desk, NRC Region 4 |
| References | |
| GO2-05-065 | |
| Download: ML051090295 (2) | |
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ENERGY NORTHWEST People -Vision -Solutions P.O. Box 968
- Richland, WA
- 99352-0968 April 4, 2005 G02-05-065 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001
Subject:
COLUMBIA GENERATING STATION DOCKET NO.'50-397 REVIEW OF NRC VIOLATION 50-397/04-05-02 (NCV)
Reference:
Letter dated February 14, 2005, WB Jones (NRC) to JV Parrish (Energy Northwest), "Columbia Generating Station - NRC Integrated Inspection Report 05000397/2004005"
Dear Sir or Madam:
This i6ttefrdodumrents the licensee's position with regard to the Commission'.s non-cited violation' (NCV) '50-397/04-05-02: This'green NCV was identified for..the failure to-.
manually s'crarni'the 'reactor in accordance with Abnormal Condition Procedure ABN-ROD, Control Rod Faults, Revision 6, for an inadvertent control rod movement during maintenance. Energy Northwest does not contest the violation but would like to note that its position differs from that of the NRC in that we believe that this issue is one of an inadequate procedure rather than a failure to follow procedures. In this case, the procedure allowed multiple courses of action depending on the interpretation of the wording used to describe the entry conditions. Energy Northwest maintains that this violation is more appropriately characterized as a violation of Technical Specification 5.4.1.a for the ambiguous guidance provided by the ABN-ROD procedure.
The referenced inspection report concluded that Energy Northwest should have followed the immediate operator actions of procedure ABN-ROD section 3.2.1 and manually scrammed the reactor following the unplanned rod movement on June 10, 2004. Energy Northwest would like to note that the procedure in place at the time of the event allowed an alternative course of action described in section 4.9 (Recovery from a Mispositioned Control Rod).
The decisions made by the control room operators were based on an assessment of control room indications after thae event including: 1) the absence.of a valid scram signal (ie., the blue 'scram' lights were not illuminated indicating that the scram valves were co's'ed "an'd no other jlarif process condition existed that would have.caused a Reactor Protection System actuation), 2) the occurrence and immediate clearing of a control 1
REVIEW OF NRC VIOLATION 50-397/04-05-02 (NCV)
Page 2 drive system suction pressure alarm associated with a rod movement, 3) the absence of rod drift alarms, 4) indication from the Rod Worth Minimizer that a rod was not at its intended position, and 5) communications from the field providing knowledge that a local rod actuation may have occurred. These initial plant conditions and indications best met the entry conditions for section 4.9 for the recovery of a mispositioned control rod. As directed by the procedure, the operators assessed the fuel limits, reduced reactor power, consulted with the station nuclear engineer, and fully inserted the rod in response to this event. The operators had no indications that the rod had malfunctioned or otherwise failed to fully insert following a valid RPS signal which is the premise of section 3.2.1 and the inspection report findings.
Subsequent evaluation of the guidance provided by the ABN-ROD procedure revealed differing professional opinions regarding the proper response to this event.
Accordingly,-the procedural guidance of ABN-ROD'was-revised to clarify'the requifed-actions.
Energy Northwest considers this matter to be important from a nuclear safety perspective. Although there were no apparent consequences for this particular event, the potential exists for an unplanned reactivity change to challenge fuel thermal limits with an increased probability for fuel damage. Energy Northwest believes that the operating crew's actions were reasonable in responding to the conditions while following the procedural guidance. The ABN-ROD procedure has been subsequently revised to address the apparent ambiguities and to promote consistent operator responses in case of a similar event.
Should you have any questions or desire additional information regarding the matter, please contact Mr. Greg Cullen at (509) 377-6105.
Respectfully, DK Atkinson Vice President, Nuclear Generation Mail DrodpPE08 cc:
BS Mallett - NRC RIV RN Sherman - BPA/1399 BJ Benney - NRC NRR WA Horin - Winston & Strawn NRC Sr. Resident Inspector-988C