05000298/FIN-2015002-01
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Finding | |
|---|---|
| Title | Failure to Prevent Reactor Thermal Power from Exceeding 2419 MWt for Preplanned Activity |
| Description | The inspectors identified a non-cited violation of Technical Specification 5.4.1.a, associated with the licensees failure to appropriately implement General Operating Procedure 2.1.10, Station Power Changes, Revision 107. Specifically, the procedure required in Step 10.3 that the licensee, Ensure any pre-planned evolution (e.g., pressure change, flow change, etc.) will not result in operation greater than 2419 MWt. On May 8, 2015, the licensee failed to implement Step 10.3 of General Operating Procedure 2.1.10, when they failed to reduce power to ensure that reactor power did not exceed 2419 MWt as the reactor recirculation motor generator B scoop tube was unlocked. As a result of this failure to reduce power for this planned evolution, reactor power increased to 2422 MWt. The licensee entered this deficiency into their corrective action program for resolution as Condition Report CR-CNS-2015-04259. The performance deficiency is more than minor, and therefore a finding, because it is associated with the human performance attribute of the Initiating Events Cornerstone objective to limit the likelihood of events that upset plant stability and challenge safety functions during shutdown as well as power operations. Specifically, the licensee did not know the condition of the reactor recirculation motor generator set B potentiometer prior to unlocking it and failed to reduce power such that when the scoop tube was unlocked, the resulting power increase would not exceed 2419 MWt. The inspectors screened the finding using Inspection Manual Chapter 0609, Appendix A, Exhibit 2, Section C, Reactivity Control Systems, which resulted in a Yes answer to Question 2 since the finding involved control manipulations that unintentionally added positive reactivity. This referred the inspectors to Inspection Manual Chapter 0609, Appendix M, Significance Determination Using Qualitative Criteria. A Senior Reactor Analyst performed a bounding qualitative evaluation and determined that the finding was of very low safety significance (Green) because of the relatively small magnitude of the overpower event, the prompt operator actions to return power to below the licensed limit upon discovery, and the fact that the overpower event did not result in any failure of the fuel cladding. This finding has a cross-cutting aspect in the area of human performance associated with conservative bias. Specifically, the affected evolution was known in advance to have the possibility of a positive reactivity impact; however, operators did not take appropriate actions to reduce power sufficiently prior to unlocking the reactor recirculation motor generator set B scoop tube in order to prevent the reactor from exceeding 2419 MWt [H.14]. |
| Site: | Cooper  |
|---|---|
| Report | IR 05000298/2015002 Section 1R13 |
| Date counted | Jun 30, 2015 (2015Q2) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | J Melfi J Nance M Phalen P Elkmann P Hernandez P Nizov R Azua C Henderson G Warnick |
| Violation of: | Technical Specification - Procedures Technical Specification |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Cooper - IR 05000298/2015002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Cooper) @ 2015Q2
Self-Identified List (Cooper)
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