Finding | |
|---|---|
| Title | Improper Troubleshooting Results in Reactor Trip Signal and Loss of Source Range Nuclear Instrument Power |
| Description | The inspectors reviewed a Green,self-revealed non-cited violation of Technical Specification 5.4.1.a Procedures, because PG&E personnel failed to follow the requirements of MA1.DC54, Conduct of Maintenance, Revision 15. Specifically, on March 20, 2018, with the reactor in Mode 3 during informal troubleshooting of high background count rate on source range nuclear instrument (NI) NI-32, PG&E personnel caused a short in NI cabinet B resulting in a blown fuse and the loss of power to the cabinet. This resulted in the loss of power to power range NI-42, intermediate range NI-36, source range NI-32, a reactor trip signal, a turbine trip signal, and all associated reactor protection interlocks. Power was automatically removed from the remaining source range NI due to reactor protection interlock P-10, resulting in no safety-related source range NI indication being available for control room operators. |
| Site: | Diablo Canyon  |
|---|---|
| Report | IR 05000323/2018001 Section 1R20 |
| Date counted | Mar 31, 2018 (2018Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.2 |
| Inspectors (proximate) | C Newgent J Reynoso W Sifre L Brookhart N Greene J O'Donnell M Haire |
| Violation of: | Technical Specification - Procedures |
| INPO aspect | WP.1 |
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Finding - Diablo Canyon - IR 05000323/2018001 | |||||||||||||||||
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Finding List (Diablo Canyon) @ 2018Q1
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