Event Notification Report for June 27, 2024

DAMAGED GAUGE

The following is a summary of information that was provided by the licensee via phone:

At 1530 CDT on 6/19/2024, the radiation safety officer (RSO) at Geo Technology, LLC was notified about a water truck that was unable to stop and ran over an InstroTek nuclear gauge. The gauge was a model explorer 3400 (serial number 3379) which contains 370 MBq of Cs-137 and 1.48 GBq of Am-241/Be. The site reported that the source inside the gauge was able to be retracted to the shielded position. The RSO plans to inspect the gauge and perform surveys.

AGREEMENT STATE REPORT - UNPLANNED CONTAMINATION

The following information was provided by the New York State Department of Health (NYSDOH) via email:

"NYSDOH received a call from the radiation safety officer of NRD on May 8, 2024, regarding a worker that had detectable amounts of contamination on their hand upon exiting a restricted area (smoke detector assembly). [The smoke detector assembly] area is not classified as an airborne radioactive materials area therefore the only personal protective equipment (PPE) required is coveralls, booties, gloves, and dust masks (to [discourage] touching of mouth/nose with gloved hands). Additionally, there is no continuous air monitoring in these areas.

"The individual had surveyed themselves upon leaving the assembly lab (Am-241 would be the target isotope) and it was determined that only one hand (dominant hand) had been contaminated. The contamination on their hands was determined to be 242 disintegrations per minute per one hundred centimeters squared (DPM/100cm^2). Following detection, the individual underwent a full body frisk and survey by environmental health and safety and underwent nasal swabs, all of which returned results below background. The individual will be placed on special bioassay collection as a confirmatory measure. Following the detection of contamination on this individual's hand, they were instructed to wash and scrub the affected areas on their palm and fingers. Following this decontamination, the individual was resurveyed and the surveys showed that the contamination had been successfully removed.

"NRD, LLC was able to interview the individual and discovered that upon leaving the assembly lab, the worker had doffed PPE, including gloves, and removed a layer of the sticky mat for the room with their bare hands. Following removal and disposal of the sticky pad layer, the individual surveyed their hands and feet which led to the discovery of contamination on their hands. NRD, LLC performed a large area removable [contamination] survey of the area in which this event occurred and found no contamination in excess of action limits requiring decontamination.

"Urinalysis results (24-hour cumulative collection) indicated undetectable concentration of Am-241 in the individual's urine, therefore no intake was suspected from this event. NRD's investigation determined that the cause of this event was improper following of procedures by the worker. Corrective actions included retraining of the employee and other staff within smoke [detector] assembly [area]. This incident is now closed."

NY Incident Number: 1484

AGREEMENT STATE REPORT - UNPLANNED CONTAMINATION

The following is a summary of information provided by the New York State Department of Health (NYSDOH) via email:

"NYSDOH received an email from the radiation safety officer of NRD on 6/11/2024 to indicate that a non-routine bioassay was started for an employee due to hand contamination. The employee's hand was decontaminated with soap and water and a whole-body frisk and nasal swabs were conducted. The whole-body count and nasal swabs were less than background.

"[After NYSDOH inquiry, the licensee subsequently reported that] the incident occurred on 6/10/2024 at 1630 EDT and was identified when the employee was leaving the facility. As a standard procedure implemented by license condition, the employee was frisking hands and feet for potential removable contamination. It was discovered upon frisking that the employee had 758 disintegrations per minute of suspected Am-241 on the palm of their left hand when leaving the facility. This amount of alpha skin contamination is 63 times the incident levels established on the license.

"[The employee] was transferring contaminated personal protective equipment (PPE) bags into a B25 [shielded waste] container. [The employee is believed to have] incorrectly doffed gloves. No other individuals had contamination present. A survey was performed of the area showing no contamination in excess of background levels on the surfaces, including the external surface of the B25 container.

"NRD is still performing an investigation, reporting their findings, and providing NYSDOH with bioassay data for this employee.

"It is unclear if this event truly meets the reportability criteria by 10 CFR 20.2203(a)(3)(i) or (ii), however, NYSDOH wishes to voluntarily report this event in the event [it is reportable,] regardless of applicability. NYSDOH will provide updates as appropriate regarding this incident."

NYSDOH Incident Number 1489

TECHNICAL SPECIFICATION REPORTABLE OCCURRENCE

The following information was provided by the licensee via phone and email:

"In accordance with Technical Specification (TS) 6.7.2.1, a report is required to be made within 24 hours by telephone, confirmed by digital submission or fax to the NRC Operations Center if requested, and followed by a report in writing to the NRC, Document Control Desk, Washington, D.C. within 14 days that describes the circumstances associated with eight different specifications, one of which, (h), is abnormal and significant degradation in reactor fuel, cladding, or coolant boundary.

"At approximately 0900 MDT this morning, abnormal and significant degradation in reactor cladding was observed on fuel element 681E, an aluminum-clad element being inspected for removal from service. The degradation was in the form of an L-shaped hole, approximately 0.25 inches long in the upper section of the fuel element body approximately one inch from the top edge, where the upper aluminum pin and upper graphite section meet internally. It is unknown how long this damage has existed, as there is no visual record of any of this fuel since first inspected in 2003 at the VA Omaha TRIGA reactor before USGS took possession. At that point, it did not have this damage. According to the records, it was dropped during handling in 2003 when it was being unloaded from the shipping cask here at the GSTR [Geological Survey TRIGA Reactor], but no record of further inspection appears to exist. Therefore, this element may have been in the operating core for as long as 18 years in this condition, as USGS was first licensed to use it in 2006."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

No fission products were detected in the primary, pool, or on an air particulate detector. The damaged element remains in its storage location in the pool with no other mitigating measures planned in the near term.

SHUTDOWN REQUIRED BY TECHNICAL SPECIFICATIONS

The following information was provided by the licensee via email:
"At 0159 EDT on 6-27-24, DC Cook Unit 2 commenced a controlled shutdown to address identified leakage through 2-QRV-251, CVCS [chemical and volume control system] charging pumps discharge flow control valve, valve packing. The leakage started at 2303 EDT on 6-26-24 and was determined to be greater than the 10 gallons per minute limit per technical specification 3.4.13 allowable leakage. The leakage was determined to not be repairable at power.

"Per 10CFR 50.72(b)(2) this is a 4 hour non-emergency report for Technical Specification required shutdown."

The NRC Resident Inspector was notified.

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
A normal shutdown is expected to be completed by 0900 EDT. There are no radiological releases. Unit 1 was not affected. There is no estimate for the time of the repairs.

AUTOMATIC START OF TURBINE DRIVEN AUXILIARY FEEDWATER PUMP

The following information was provided by the licensee email:

"On June 27, 2024, at 0804 [EDT], D.C. Cook Unit 2 had an automatic start of the turbine driven auxiliary feedwater pump (TDAFP) following a controlled down power and manual reactor trip at approximately 17 percent power. The automatic start of the TDAFP was due to a steam generator water level 'low low' signal following the reactor trip. The down power and trip were performed in accordance with normal shutdown procedures to comply with the required action C.1 of technical specification 3.4.13, 'reactor coolant system operational leakage.' Reference event notification number EN57194.

"An automatic start of the TDAFP is an eight hour report per 10CFR 50.72(b)(3)(iv)(A).

"Unit 2 is being supplied by offsite power. All control rods fully inserted. Steam generators are being fed by both motor driven auxiliary feedwater pumps. Decay heat is being removed via the steam dump system to the main condenser. Preliminary evaluation indicates plant systems functioned normally following the reactor trip. D.C. Cook Unit 2 remains in Mode 3 to repair the previously reported reactor coolant system leakage through valve 2-QRV-251, 'CVCS [chemical and volume control system] charging pumps discharge flow control' valve packing."

The NRC Resident Inspector has been notified.

TECHNICAL SPECIFICATION (TS) REPORTABLE OCCURRENCE

The following information was provided by the licensee via phone and email:

"On June 27, 2024, at 1037 EDT, the North Carolina State University (NCSU) PULSTAR reactor was shutdown due to channel failure of the N-16 detector. This channel is required during operations over 500 kW by TS 3.4a. The reactor was operating at 950 kW at the time of channel failure. The reactor operator promptly shutdown and secured the reactor. Due to the nature of an unscheduled shutdown, investigation as to the source of channel failure and remedy will be commenced. At this time, failure has been isolated to just the N-16 channel. As such, operations may continue with approval for restart by the director of the NCSU PULSTAR reactor at powers below 500 kW. To resume full operations, channel maintenance, required surveillances, and additional approval by the director of the NCSU PULSTAR reactor are required."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

The N-16 channel provides a reference power level indication while adjustments are being made to other power level channels.