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| Discovered date | Reporting criterion | Title | Description | LER | |
|---|---|---|---|---|---|
| ENS 56553 | 2 June 2023 12:18:00 | Non | Unscheduled Shutdown | The following information was provided by the licensee via fax or email: An unscheduled shutdown of the reactor occurred on 6/2/23 at 0818 EDT due to an abnormal response of the Safety Power Level channel during the approach to power of 1 MW at 150 kW. The Reactor Operator observed a discrepancy in power indications by the Linear Power Level and Safety Power Level channels and took immediate actions required by procedure NRP-OP-105, Response to SCRAMS, Alarms, and Abnormal Conditions. The reactor was shut down and secured immediately. The Designated Senior Reactor Operator was immediately notified. The Safety Power Level channel is required to be operable per Technical Specification 3.3.b Table 3.3-1 while the reactor is being operated. During the startup checklist, the channel performed satisfactorily. The Safety Power Level channel is part of the reactor safety system and has two automatic shutdowns (SCRAMs) associated with it. Reactor power was correctly monitored by all other operable power monitoring channels which have redundant SCRAM capabilities. No SCRAM occurred or was needed due to the power level of the reactor. Following the reactor shutdown, the reactor staff investigated and determined that the high voltage power supply in the Safety Power channel was faulty. The power supply was replaced and a channel calibration of the Safety Power channel will be performed using procedure PS 1-05-03A:S1 to verify the channel is operable. Maintenance Log #0888 has been opened. There was no safety issue with this event. Procedures were followed during reactor operation, shutdown, and the investigation. This unscheduled shutdown is a reportable event per TS 6.7.1 based on the circumstances and as defined in the facility Technical Specification (TS 1.2.24.d) for reportable events from operation in violation of Limiting Conditions for Operation (LCO) established in TS. TS 1.2.24.d, does not allow for an exception for taking prompt remedial action. A report to the NRC is required within one working day and will be made by 1700 EDT by phone on 6/2/23, as required by TS 6.7.1. Also as required by TS 6.7.1, a written report to the NRC is due in 14 days (6/16/23). | |
| ENS 55747 | 17 February 2022 18:46:00 | Non | Technical Specification Violation | The following is a summary of information provided by the licensee via telephone: On February 17, 2022 at 1346 EST, while the reactor was operating at 95 percent power, the North Carolina State University test reactor was manually shutdown due to an incorrect power meter reading. The power meter was reading 20 percent power. The incorrect power meter reading violated technical specification 3.4. The facility director was notified of the event. The reactor is shutdown and secured. The NRC Project Manager was notified. | |
| ENS 52748 | 10 May 2017 21:00:00 | Non | Research Test Reactor - Technical Specification Violation | On Wednesday May 10, 2017 at approximately (1700 EDT), the Reactor Operator (RO) that was signed in on the reactor console logbook completed a ('key on') checklist in preparation for a routine reactor startup. The RO left the control room and brought the log book to the reactor bridge for the Designated Senior Reactor Operator (DSRO) to sign off for the ('key on') startup. The RO immediately realized his mistake concerning the procedural requirement for a reactor operator to be present in the control room at all times when the reactor is not secured (procedure OP-103), and returned to the control room. The DSRO followed the RO to the control room and observed that the reactor key was in the on position, the control rods were all fully inserted, and reactor power was at residual levels. The reactor was shutdown, but was not secured. The DSRO determined that this constituted a violation of procedure OP-103 and could be a Reportable Occurrence as defined under Technical Specification 1.2.24 h. The DSRO reviewed Technical Specification (TS) 6.6.2, Action to be Taken in the Event of a Reportable Occurrence. The DSRO determined that under TS 6.6.2a that reactor conditions had been returned to normal by the presence of the licensed operator in the control room. The DSRO then signed the Key On checklist authorization for reactor startup and the reactor was started. The DSRO spoke with the Manager of Engineering and Operations (MEO) by telephone about this matter at approximately 1800 on May 10, 2017. The MEO concurred that procedure OP-103 was violated and would be reportable to the Nuclear Regulatory Commission (NRC). The DSRO and MEO agreed to discuss this matter with the Director, Nuclear Reactor Program and the Reactor Health Physicist on May 11, 2017. The MEO stated on May 11, 2017 that TS 6.1.3a, the specification implemented by procedure OP-103, was not met. It was agreed that required notifications to NRC would be made by (1700) on May 11, 2017 to meet the 24 hour notification requirement. | |
| ENS 47182 | 23 August 2011 18:30:00 | Other Unspec Reqmnt | Notification of an Unusual Event Due to a Seismic Event | The licensee declared a Notification of Unusual Event due to seismic activity. Equipment walkdowns performed. The licensee also terminated the event at the time of notification. | |
| ENS 46484 | 13 December 2010 20:00:00 | Non | Research Reactor Radiography Incident | On 12/13/10 at 1500 EST, North Carolina State University (NCSU) was conducting routine radiography with the reactor at 1MW when unknown to the technician, the shutter stuck open. The technician entered the shielded room and noticed the shutter wasn't closed and immediately left the exposure room. After the technician left the room and secured the area, he notified other personnel including the control room. NCSU reports that the reactor was shut down by the operator because of this event. After the reactor was shut down, personnel entered the room and closed the shutter. The shutter door interlock had malfunctioned due to a mechanical interference. It was noted that the technician was not wearing personal dosimetry. NCSU estimates (based on cameras and a re-enactment conducted with the technician) that the technician was exposed for a maximum of 18 seconds with a resulting dose rate of about 150 mRem. NCSU corrective actions include a research reactor shutdown, closing of the radiography shutter, installing interlocks to prevent shielded room access with the shutter not fully closed, and safety training of personnel related to use of the radiography facility. NCSU is making this report in accordance with their research reactor technical specifications. | |
| ENS 44991 | 10 April 2009 13:30:00 | Non | Violation of Limiting Conditions in Technical Specification 3.5B | On Monday, 13 Apr 2009 at approximately 9 AM, the stack sample pump was observed to be off. On Friday, 10 Apr 2009, the reactor operated from approximately 11 AM to 4 PM. Upon investigating this situation it was learned that at approximately 9:30 AM on 10 Apr 2009 the stack sample pump apparently lost power. The stack pump remained off until being re-started on 13 Apr 2009. Technical Specification (TS) 3.5b requires the stack particulate and stack gas radiation monitoring channels to be operable during reactor operation. With the stack sample pump off, neither of these two channels were operable during reactor operation on 10 Apr 2009. The Auxiliary GM may serve as a substitute for one of the two required channels. As a result, the reactor was operated on 10 Apr 2009 in violation of TS 3.5b. This event is a reportable event as defined in TS (1.2.24d and 6.6.2) under TS 6.7.1 since both channels were not operable as required by the Limiting Conditions for Operation TS 3.5b. The US Nuclear Regulatory Commission (NRC) was notified by telephone on 14 Apr 2009 at approximately 4 PM. The event will be investigated further with a detailed explanation of the event and actions taken and planned to prevent recurrence. The NRC will be given a written report on or before 24 Apr 2009. Consequences of this event were not significant. Other radiation monitors were in service to monitor airborne radioactive effluent and reactor bay airborne activity. All of those monitors indicated typical radiation levels during reactor operation. |