Event Notification Report for January 31, 2019

BOTH EMERGENCY DIESEL GENERATORS INOPERABLE DUE TO LOW AIR TEMPERATURE

"At 0743 [CST] on 1/31/2019, both trains of Unit 2 Diesel Generators were declared INOPERABLE due to outside air temperature exceeding the low temperature design limit for the diesel engines; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v) for an event or condition that could have prevented the fulfillment of a safety function. The Unit 2 Diesel Generators are still able to start if necessary to provide power. Additionally, multiple layers of defense in depth measures are in place to ensure safety. Prairie Island has five sources of offsite power; all of which are currently available. The Unit 1 Diesel Generators are OPERABLE and capable of being cross-connected to Unit 2. Additional equipment capable of responding to beyond design basis events is available on site providing another layer of defense in depth.

"Both Unit 2 Diesel Generators were returned to an OPERABLE status at 0810 on 1/31/2019 based on outside air temperature rising above the low temperature design limit with forecasted temperatures to remain above the low temperature design limit.

"There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."

The air temperature limit was -30 degrees Fahrenheit.

Unit 1 was not affected. The EDGs were supplied by a different manufacturer with different air temperature limits.

* * * RETRACTION AT 1340 EDT ON 03/22/2019 FROM BRIAN JOHNSON TO JEFFREY WHITED * * *

"Engineering analysis performed subsequent to the event notification has determined that both Unit 2 Diesel Generators would have been able to fulfill their safety function during the period of time when the outside air temperature had exceeded the low temperature design limit. Therefore, EN# 53853 is being retracted.

"The NRC Resident Inspector has been notified of the event notification retraction."

Notified R3DO (McCraw).

REPORT OF LOSS OF AM-241 SOURCES CONTAINED IN HELICOPTER LASERS

The following is a summary of a call with the US Army Aviation Missile Command.

While taking inventory of sources located in decommissioned helicopter lasers, the US Army Aviation Missile Command identified that they were missing 88 Am-241 sources located in 44 helicopter lasers. It can not be determined exactly where the sources were lost, though the licensee is going to provide possible options, including that the lasers could have been lost during combat. It is assumed that the sources are not in public areas. It can not be determined when the sources were lost.

The licensee noted that it is unlikely anyone would receive a dose as a result of this loss of material because it is difficult to retrieve the sources.

The US Army continues to attempt to find the sources during routine house keeping activities. They have a similar license for a new aircraft and will perform inventory checks more frequently to ensure that any losses are more promptly reported.

The licensee has notified the NRC Regional Office.

THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

MANUAL REACTOR TRIP - CIRCULATING WATER ICING CONDITIONS

"At 0301 [EST] on 1/31/19, with Unit 2 in Mode 1 at 100% power, the reactor was manually tripped due to icing conditions requiring the removal of 4 Circulating Water Pumps from service. The trip was not complex, with all systems responding normally post-trip. 21 CFCU [Containment Fan Cooler Unit] was inoperable prior to the event for a planned maintenance window and did not contribute to the cause of the event and did not adversely impact the plant response to the trip. An actuation of the Auxiliary Feedwater System occurred following the manual reactor trip. The reason for the Auxiliary Feed Water System auto-start was due to low level in a steam generator. Operations responded and stabilized the plant. Decay heat is being removed by the Main Steam Dumps and Auxiliary Feedwater System.

"Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an eight hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the Auxiliary Feed Water System. There was no impact on the health and safety of the public or plant personnel.

"The NRC Resident Inspector has been notified."

The icing condition was described as frazil ice.

Unit-1 reduced power to 88% because one circulating water pump was shutdown.

FALSE NEGATIVE INDICATED ON A FITNESS FOR DUTY BLIND QUALITY ASSURANCE TEST

"On 1/31/2019, the Medical Review Officer for Seabrook was notified of an error made by the HHS [Health and Human Services] certified lab resulting in a false negative Fitness for Duty quality assurance test result. The test lab, Quest Diagnostics-Norristown, was provided an adulterated sample specimen that was part of a blind performance test, which tested negative. This false negative test result will be investigated and the results reported as required.

"This event is being reported in accordance with 10 CFR 26.719(c)(3).

"NRC Resident Inspector has been notified."