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This notification is being made in accorda … This notification is being made in accordance with 10CFR50.73(a)(2)(iv)(A) to provide the NRC with information pertaining to the invalid Primary Containment Isolation System (PCIS) Group III actuation signal that affected containment isolation valves in more than one system.</br>On July 31, 2004 at 1356 (EDT) with the reactor at full power, the power supply that provides power to the Reactor Protection System (RPS) Channel 'A' of the Reactor Building Ventilation Exhaust Rad Monitor and RPS Channel 'A' of the Refuel Floor Rad Monitor was momentarily lost causing an invalid PCIS Group III actuation. Operators immediately verified the plant response to the loss of RPS 'A', backed up the Group III actuation manually, walked down the control room panels, shifted RPS 'A' bus to the alternate power supply, secured 'A' RPS MG set and restored the affected plant equipment to a normal line-up. The following systems were observed to have performed as follows:</br>The PCIS functioned successfully providing a complete Group III isolation. Both trains of the Standby Gas Treatment System started and operated as designed. </br>The PCIS Group Ill isolation involved isolation of valves in the following systems:</br>Drywell Air Purge and Vent, Drywell and Suppression Chamber Main Exhaust, Suppression Chamber Purge</br>and Vent, Containment Air Compressor Suction Valve, Exhaust to Standby Gas Treatment, Containment Purge </br>Supply and Makeup, Containment Air Sampling, Air Dilution Subsystem Valves, Vent Subsystem Valves, and </br>Containment Air Dilution Vent System MOV VG-22 A/B.</br>Repairs were subsequently made to the 'A' RPS power supply and the system was returned to normal status. This event has been entered into Entergy Nuclear Vermont Yankee's Corrective Action Program.</br>The licensee will notify the NRC Resident Inspector.ee will notify the NRC Resident Inspector. +
17:56:00, 31 July 2004 +
41,004 +
14:14:00, 1 September 2004 +
17:56:00, 31 July 2004 +
This notification is being made in accorda … This notification is being made in accordance with 10CFR50.73(a)(2)(iv)(A) to provide the NRC with information pertaining to the invalid Primary Containment Isolation System (PCIS) Group III actuation signal that affected containment isolation valves in more than one system.</br>On July 31, 2004 at 1356 (EDT) with the reactor at full power, the power supply that provides power to the Reactor Protection System (RPS) Channel 'A' of the Reactor Building Ventilation Exhaust Rad Monitor and RPS Channel 'A' of the Refuel Floor Rad Monitor was momentarily lost causing an invalid PCIS Group III actuation. Operators immediately verified the plant response to the loss of RPS 'A', backed up the Group III actuation manually, walked down the control room panels, shifted RPS 'A' bus to the alternate power supply, secured 'A' RPS MG set and restored the affected plant equipment to a normal line-up. The following systems were observed to have performed as follows:</br>The PCIS functioned successfully providing a complete Group III isolation. Both trains of the Standby Gas Treatment System started and operated as designed. </br>The PCIS Group Ill isolation involved isolation of valves in the following systems:</br>Drywell Air Purge and Vent, Drywell and Suppression Chamber Main Exhaust, Suppression Chamber Purge</br>and Vent, Containment Air Compressor Suction Valve, Exhaust to Standby Gas Treatment, Containment Purge </br>Supply and Makeup, Containment Air Sampling, Air Dilution Subsystem Valves, Vent Subsystem Valves, and </br>Containment Air Dilution Vent System MOV VG-22 A/B.</br>Repairs were subsequently made to the 'A' RPS power supply and the system was returned to normal status. This event has been entered into Entergy Nuclear Vermont Yankee's Corrective Action Program.</br>The licensee will notify the NRC Resident Inspector.ee will notify the NRC Resident Inspector. +
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100 +
00:00:00, 1 September 2004 +
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>.
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14:14:00, 1 September 2004 +
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31.846 d (764.3 hours, 4.549 weeks, 1.047 months) +
17:56:00, 31 July 2004 +
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