ENS Event | |
|---|---|
22:00 Sep 14, 2023 | |
| Title | Technical Specification Reportable Occurrence |
| Event Description | The following information is a summary provided by the licensee via phone and email:
On September 7, 2023, a Senior Reactor Operator (SRO) noted that power indication channel 1 and channel 2 initially responded abnormally during preoperational checks. It was determined that the data acquisition system (DAS) system had been de-energized possibly by a power outage the night before. The DAS was re-energized and channel 1 and channel 2 both returned to normal. Preoperational checks were able to be completed but the reactor start up was not completed due to time. On September 14, 2023, the licensee was concerned regarding the initial abnormal response of the power indications when the DAS was de-energized, and it was determined that further investigation was needed to fully understand the potential effects on the reactor power channel indications. A plan was developed and approved by the Reactor Administrator to perform applicable steps of OP-1 to perform pre-operational and rod-drop tests with DAS energized and with DAS de-energized. All indications and pre-operational checks were normal with DAS energized. A rod drop test was performed while de-energizing DAS to determine the effect if any on reactor power and scram functionality. Safety rod 1 and 2 were raised (reactor not critical), data recorded, then the power to DAS was removed. The power readings after DAS was de-energized were as follows: channel 1 - 150 cps (counts per second), channel 2 - off scale high on meter and chart recorder, channel 3 - 33 percent of 10 mW. The SRO noted that reactor did not scram when channel 2 indicated off scale high. The SRO manually scram the reactor, power to DAS was restored, and all indications returned to normal. An attempt to perform the pre-operational checks with DAS de-energized was aborted due to channel 1 and 2 indicating abnormally. The licensee contacted the NRC Project Manager. |
| Where | |
|---|---|
| Idaho State University (Idah) Pocatello, Idaho (NRC Region 0) | |
| License number: | R-110 |
| Reporting | |
| Non | |
| Time - Person (Reporting Time:+15.57 h0.649 days <br />0.0927 weeks <br />0.0213 months <br />) | |
| Opened: | Mary Lou Dunzik-Gougar 13:34 Sep 15, 2023 |
| NRC Officer: | Kerby Scales |
| Last Updated: | Sep 15, 2023 |
| 56740 - NRC Website | |
Idaho State University (Idah) with Non | |
WEEKMONTHYEARENS 567402023-09-14T22:00:00014 September 2023 22:00:00
[Table view]Non Technical Specification Reportable Occurrence 2023-09-14T22:00:00 | |