Event Notification Report for June 28, 2024

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

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.