The following information was provided by the licensee via email:
At 0838 [MDT] on May 21, 2022, the diesel fuel day tank level transmitter for the B Central Utility Building (CUB) Standby Diesel Generator failed low. The failed level transmitter signaled the automatic start of the fuel oil transfer pump. When the transfer pump started, it pumped off-highway diesel fuel from the 8000 gallon bulk storage tank, located on the south side of the CUB, to the 150 gallon day tank which was already at its normal operating level of 70-90 percent. Since the level instrument had failed low, the transfer pump continued to run. Level in the day tank continued to rise and diesel fuel spilled from the day tank vent, located above and to the side of the CUB roof. The transfer pump continued to run for 23 minutes until an operator shut down the pump. This stopped the release. An estimated maximum of 240 gallons of diesel fuel was spilled. Most of the diesel fuel landed on the ground outside of the CUB in an area covered by gravel. There were no injured personnel and no radiation exposure as a result of this event.
The plant is in a safe, stable condition. The B CUB Standby Diesel Generator does not perform a safety function. The transfer pump has been placed out of service. The area is currently being cleaned of diesel fuel. This event has been entered in Urenco USA's corrective action program as EV151632.
This event was reported to the
New Mexico Environment Department at 0643 MDT on May 22, 2022 and is being reported concurrently to the NRC.