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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)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation signal affecting more than one system.</br>On September 19, 2011, at 1000 hours Central Daylight Time (CDT), during the performance of a maintenance activity on the Reactor/Refueling Zone Ventilation Radiation Monitor BFN-3-RM-090-0141/143, Browns Ferry Unit 3 received a Primary Containment Isolation System (PCIS) Group 6 isolation. This resulted in isolation of the reactor and refuel zone ventilation systems, initiation of the Standby Gas Treatment System (Trains A, B and C), and the initiation of the Control Room Emergency Ventilation System (Trains A and B). All plant systems responded as designed.</br> </br>There are two divisions of Reactor/Refueling Zone Ventilation Radiation Monitors: BFN-3-RM-090-0140/142 and BFN-3-RM-090-0141/143. A downscale or inoperable signal in both divisions will initiate the PCIS Group 6 isolation. Prior to the performance of the maintenance activity, BFN-3-RM-090-0140/142 was functional. However, during a field walkdown after the PCIS Group 6 isolation, relay BFN-3-RLY-064-16AK62A for BFN-3-RM-090-0140/142 was discovered to be chattering. A chattering relay could cause momentary loss of continuity between the contacts which would effectively generate a spurious isolation signal from that division. Thus, when 3-RM-090-0141/143 was made inoperable by the surveillance, the PCIS Group 6 logic was made-up.</br>The PCIS Group 6 isolation was reset at 1008 CDT. This event was entered in the Corrective Action Program as Problem Evaluation Report (PER) 434799. There were no safety consequences or impact on the health and safety of the public as a result of these events. The NRC Senior Resident Inspector was notified.RC Senior Resident Inspector was notified. +
16:00:00, 19 September 2011 +
47,450 +
13:53:00, 17 November 2011 +
16:00:00, 19 September 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)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation signal affecting more than one system.</br>On September 19, 2011, at 1000 hours Central Daylight Time (CDT), during the performance of a maintenance activity on the Reactor/Refueling Zone Ventilation Radiation Monitor BFN-3-RM-090-0141/143, Browns Ferry Unit 3 received a Primary Containment Isolation System (PCIS) Group 6 isolation. This resulted in isolation of the reactor and refuel zone ventilation systems, initiation of the Standby Gas Treatment System (Trains A, B and C), and the initiation of the Control Room Emergency Ventilation System (Trains A and B). All plant systems responded as designed.</br> </br>There are two divisions of Reactor/Refueling Zone Ventilation Radiation Monitors: BFN-3-RM-090-0140/142 and BFN-3-RM-090-0141/143. A downscale or inoperable signal in both divisions will initiate the PCIS Group 6 isolation. Prior to the performance of the maintenance activity, BFN-3-RM-090-0140/142 was functional. However, during a field walkdown after the PCIS Group 6 isolation, relay BFN-3-RLY-064-16AK62A for BFN-3-RM-090-0140/142 was discovered to be chattering. A chattering relay could cause momentary loss of continuity between the contacts which would effectively generate a spurious isolation signal from that division. Thus, when 3-RM-090-0141/143 was made inoperable by the surveillance, the PCIS Group 6 logic was made-up.</br>The PCIS Group 6 isolation was reset at 1008 CDT. This event was entered in the Corrective Action Program as Problem Evaluation Report (PER) 434799. There were no safety consequences or impact on the health and safety of the public as a result of these events. The NRC Senior Resident Inspector was notified.RC Senior Resident Inspector was notified. +
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100 +
00:00:00, 17 November 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>.
22:26:28, 24 September 2017 +
13:53:00, 17 November 2011 +
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58.87 d (1,412.88 hours, 8.41 weeks, 1.935 months) +
16:00:00, 19 September 2011 +
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