Event Notification Report for May 26, 2022

AGREEMENT STATE REPORT - DISCOVERED FIXED GAUGE

The following information was received from the Oklahoma Department of Environmental Quality (DEQ) via email:

"On 5/17/2022, the state of Arkansas notified Oklahoma DEQ's Radiation Management Section that a DOT [(Department of Transportation)] Special Permit 10656 had been issued for a trailer that originated in Sallisaw, Oklahoma. The load was surveyed at the scrap metal facility in Arkansas and sent back to Oklahoma. It arrived back to Sallisaw today and was surveyed by the owner of the salvage yard. The owner of the salvage yard found a Thermo Measure Tech Model 5201 fixed gauge containing 50 mCi of Cs-137, serial number R4473. The source housing appears to be intact. When the gauge was removed from the trailer no additional radiation was measured on the trailer. The facility owner was instructed to isolate and secure the gauge. The owner stated that he would place it in a drum and lock it in a concrete shed."

DOT Approval Number: AR-OK-22-007

NON-AGREEMENT STATE REPORT - TECHNETIUM-99M SPILL

The following is a synopsis of information provided by the licensee via phone call:

At approximately 0200 on May 19, 2022, a spill of approximately 3 curies of Tc-99m occurred in the compounding room at the Pharmalogic Puerto Rico facility in San Juan, PR. The spill was contained to the compounding room (a restricted area). One worker received a skin contamination that did not require medical attention.

CRITICALITY ACCIDENT ALARM SYSTEM SPEAKERS DISABLED

The following information was provided by the licensee via email:

"On May 18, 2022, at approximately 1450 (EDT), an electrical switch for the Criticality Accident Alarm System (CAAS) legacy speakers was noted to be out of its normal position. A functional redundant speaker system is installed in the main processing plant and laboratory. As a consequence of the switch being out of position, in the highly unlikely event that the CAAS had actuated, the alarm would not have been annunciated in areas outside of the main processing area and laboratory where there are no redundant speakers. Compliance was restored at approximately 1500 (EDT) when the switch was placed back in its normal position. The system was subsequently tested and confirmed to be operational. The most recent audibility test of the speaker system had been performed on May 13, 2022, at approximately 1100 (EDT). The licensee notified the NRC Resident Inspector on May 18, 2022, at approximately 1625 (EDT). There were no actual nuclear safety consequences. The potential consequence was that, in the event of a nuclear criticality accident, evacuation could have been delayed for those personnel outside of the main processing area where redundant speakers have not been installed."

AGREEMENT STATE REPORT - SHUTTER FAILURE

The following is a synopsis of an email received from the state of North Dakota:

On 5/18/2022, the licensee reported to the North Dakota Department of Environmental Quality an equipment failure of a nuclear device sealed source shutter manufactured by Berthold Technologies. The seal source is model SSC-100, containing 20 millicuries of Cs-137. The source holder is Berthold Technologies model LB 300 IRL Type I. The manufacturer was contacted by the licensee to come on site and evaluate the device.

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

The source is in a safe location and there was no exposure to personnel.

EN Revision Imported Date: 5/25/2022

EN Revision Text: MANUAL REACTOR TRIP FOLLOWING MANUAL TURBINE TRIP FROM HIGH VIBRATIONS ON MAIN TURBINE

The following information was provided by the licensee via email:

"On May 24, 2022, at 0414 EDT, while rolling the Unit 1 main turbine during the Unit 1 Cycle 31 refueling outage, the Unit 1 main turbine experienced high vibrations and the main turbine was manually tripped with reactor power at 12 percent. Main turbine vibrations persisted and the reactor was manually tripped, Main Steam Stop Valves were closed, and main condenser vacuum was broken.

"This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The DC Cook Resident NRC Inspector has been notified.

"Unit 1 is being supplied by offsite power. All control rods fully inserted. Both Motor Driven Auxiliary Feedwater Pumps started properly. Decay heat is being removed via Steam Generator Power Operated Relief Valves. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 1 remains stable in Mode 3 while conducting the Post Trip Review. No radioactive release is in progress as a result of this event."

EN Revision Imported Date: 5/25/2022

EN Revision Text: PROCEDURAL NONCOMPLIANCE WITH ADMINISTRATIVE ITEMS RELIED ON FOR SAFETY (IROFS)

The following additional information was obtained from the licensee by phone and email:

"Administrative IROFS WT-165 and WT-166 require independent operators to sample and verify the V-1170 uranium concentration is below an administrative limit prior to discharge to the V-1160 tank. These IROFS were correctly performed on May 18, 2022, for both the V-1170A and V-1170B tanks. In between the 18th and the 23rd, the warm caustic filter was water washed with the process solution sent to the V-1170 tanks.

"At 0422 EDT on May 23, 2022, the contents of V-1170A and V-1170B tanks were pumped to the T-1160B tank without the tank uranium concentration being updated following the warm caustic filter wash.

"At 0925 EDT on May 23, 2022, an evaluation into the reportability of the event was initiated when a Uranium Recovery and Recycling Services (URRS) team manager contacted Criticality Engineering to report the transfer without the test results required by procedure. After reviewing updated tank test results, performing calculations to determine risk, and discussing actions taken by the operators, IROFS WT-165 and WT-166 were considered failed and IROFS WT-171, WT-172, WT-175 and WT-176 were considered degraded.

"Per CSE-15C-S1-G3, the remaining safety margin was 1.000E-2, which was below the required 1.000E-4.

"The result is reportable per 10 CFR Part 70 Appendix A (b)(2), 'Loss or degradation of items relied on for safety that results in failure to meet the performance requirements of 10 CFR 70.61.'

"Following the event, the contents of V-1170A and T-1160B were tested and historical tank level indication data was reviewed with results well within the IROFS limits. There was no safety impact as a result of the failed IROFS."

DEGRADATION TO A FUEL ELEMENT CLADDING

The following information was provided by the University Of Utah Training Reactor (UUTR) via email:

"This is a written report to NRC regarding minor damage to a fuel element identified during routine fuel inspection operations, filed per UUTR Technical Specification para 6.7.2, 'Special Reports' noting degradation in a reactor fuel element cladding. On Tuesday, May 24 2022, at 1115 [MDT], during a routine UUTR bi-annual fuel inspection, one stainless steel U-235 TRIGA fuel element removed from core position D-14, element number 4138E, was noted to have low-level surface pitting and severe discoloration at several locations along the element length. When this fuel element was moved toward the inspection apparatus, at one of the pitted locations on the surface of the fuel element, a small stream of clear bubbles began to evolve. This was captured on high resolution video; the bubbles were presumed to be fission gas. Reinspection of this same fuel element one hour later with high resolution video showed no evolution of gas bubbles, and the element remained intact. Radiation levels throughout the facility remained constant and consistent with background levels.

"Response to this Event: After initial observation of the pitting and bubble evolution, the fuel element number 4138E was placed in a fuel element storage rack; local radiation levels remained at measured background levels at all times from multiple instruments. On the facility continuous air monitor, no noted deviations from background levels were observed over the entire period of concern. Radiation readings throughout the duration of this observation remained at background levels, and no significant issues or safety concerns were noted; the reactor and facility remain secure, and fuel inspection operations will continue over the next week.

"Follow-up Actions: UUTR reactor personnel will permanently remove fuel element number 4138E from service, and continue to monitor for any instance of elevated radiation levels from the reactor pool. All levels remain stable at background levels."

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

The Non-Power Reactor Project Manager will be notified and the Utah State Radiation Safety Officer was notified.

The estimated time for restart is one week.