Browse wiki
Jump to navigation
Jump to search
This 60-day telephone notification is bein … This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv) and 10 CFR 50.73(a)(1) to describe an invalid RPS (SCRAM) actuation.</br>On March 30, 2011, at 1443 hours Central Daylight Time (CDT), during a refueling outage, Browns Ferry Unit 2 received an invalid Common Accident Signal (CAS) as a result of maintenance activities.</br> </br>The CAS caused a full Unit 2 Reactor SCRAM and associated system initiations. The CAS was initiated due to invalid indications on both Channels A and B of low-low-low reactor water level, which did not exist; therefore, the actuation was invalid.</br> </br>The affected equipment responded as designed. All four Unit 1/2 Emergency Diesel Generators auto started and all four Unit 3 Emergency Diesel Generators auto started. Unit 2 received a full Reactor SCRAM and Core Spray Pumps A, B, C, and D auto started and injected into the reactor. Unit 2 Division I Residual Heat Removal (RHR) System was in Shutdown Cooling with only the C pump in service. The 'A' RHR pump auto started and Shutdown Cooling flow increased, as expected. Unit 2 Division II RHR System had been tagged out for maintenance and did not respond. High Pressure Coolant Injection and Reactor Core Isolation Cooling received auto initiation signals; however, their steam isolation valves were tagged closed and the systems did not start. The Inboard Main Steam Isolation Valves (MSIVs) isolated as a result of the CAS signal. The outboard MSIVs had been previously closed and tagged for refueling outage purposes. </br>This event was entered in the Corrective Action Program as Service Request (SR) 346544, which generated Problem Evaluation Report (PER) 346568.</br>There were no safety consequences or impact on the health and safety of the public as a result of these events.</br> </br>The NRC Senior Resident Inspector has been notified.</br>The shutdown reactor water level transmitters share a common variable leg. When maintenance unrelated to the transmitters was performed, the variable leg was lost causing the low-low-low reactor water level SCRAM signal to be generated. water level SCRAM signal to be generated.
19:43:00, 30 March 2011 +
46,880 +
18:03:00, 24 May 2011 +
19:43:00, 30 March 2011 +
This 60-day telephone notification is bein … This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv) and 10 CFR 50.73(a)(1) to describe an invalid RPS (SCRAM) actuation.</br>On March 30, 2011, at 1443 hours Central Daylight Time (CDT), during a refueling outage, Browns Ferry Unit 2 received an invalid Common Accident Signal (CAS) as a result of maintenance activities.</br> </br>The CAS caused a full Unit 2 Reactor SCRAM and associated system initiations. The CAS was initiated due to invalid indications on both Channels A and B of low-low-low reactor water level, which did not exist; therefore, the actuation was invalid.</br> </br>The affected equipment responded as designed. All four Unit 1/2 Emergency Diesel Generators auto started and all four Unit 3 Emergency Diesel Generators auto started. Unit 2 received a full Reactor SCRAM and Core Spray Pumps A, B, C, and D auto started and injected into the reactor. Unit 2 Division I Residual Heat Removal (RHR) System was in Shutdown Cooling with only the C pump in service. The 'A' RHR pump auto started and Shutdown Cooling flow increased, as expected. Unit 2 Division II RHR System had been tagged out for maintenance and did not respond. High Pressure Coolant Injection and Reactor Core Isolation Cooling received auto initiation signals; however, their steam isolation valves were tagged closed and the systems did not start. The Inboard Main Steam Isolation Valves (MSIVs) isolated as a result of the CAS signal. The outboard MSIVs had been previously closed and tagged for refueling outage purposes. </br>This event was entered in the Corrective Action Program as Service Request (SR) 346544, which generated Problem Evaluation Report (PER) 346568.</br>There were no safety consequences or impact on the health and safety of the public as a result of these events.</br> </br>The NRC Senior Resident Inspector has been notified.</br>The shutdown reactor water level transmitters share a common variable leg. When maintenance unrelated to the transmitters was performed, the variable leg was lost causing the low-low-low reactor water level SCRAM signal to be generated. water level SCRAM signal to be generated.
Has query"Has query" is a predefined property that represents meta information (in form of a <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Subobject">subobject</a>) about individual queries and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
00:00:00, 24 May 2011 +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
02:07:06, 2 March 2018 +
18:03:00, 24 May 2011 +
false +
false +
54.93 d (1,318.33 hours, 7.847 weeks, 1.806 months) +
19:43:00, 30 March 2011 +
60-Day Telephonic Notification of Invalid Rps Signal Due to Loss of Variable Leg of Level Transmitter +
URL"URL" is a <a href="/Special:Types/URL" title="Special:Types/URL">type</a> and predefined property provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a> to represent URI/URL values.