Semantic search

Jump to navigation Jump to search
 Entered dateEvent description
ENS 5385130 January 2019 17:41:00At 0910 (CST) on January 30, 2019, the Dresden Station Heater Boiler 'B' tripped while placing the station Heater Boiler 'A' in service. With colder temperatures, the density of the supply air increased and contributed to a greater quantity of air entering the Reactor Building than what was previously being supplied with heating steam in service. The Reactor Building differential pressure (DP) degraded and dropped below 0.25 inches water column vacuum. This condition represents a failure to meet Technical Specification (TS) Surveillance Requirement 3.6.4.1.1. Entry into TS 3.6.4.1 Condition A was made due to Secondary Containment becoming inoperable. Standby Gas Treatment System was initiated to assist with Reactor Building DP control. Reactor Building DP was restored to greater than 0.25 inches water column vacuum. TS 3.6.4.1 Condition A was exited. This event is being reported under 10 CFR 50.72(b)(3)(v)(C), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to ... control the release of radioactive material.' The NRC Resident Inspector has been notified.