Browse wiki
Jump to navigation
Jump to search
A finding of very low safety significance … A finding of very low safety significance and associated NCV of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was self-revealed when Instrumentation and Controls (I&C) Technicians failed to fully shut an instrument isolation valve for a Reactor Vessel Pressure Transmitter. During subsequent steps of the Surveillance Test Procedure (STP), a pressure surge occurred on the shared reference leg and RPS channels A2 and B2 initiated an automatic reactor scram due to a sensed low reactor water level. The inspectors determined that the failure to complete the steps of STP 3.3.3.2-09B was contrary to the requirements contained in 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, and was therefore a performance deficiency. The licensee entered this event into their Corrective Action Program as CAP 070334, and implemented corrective actions including enhancement of all STPs that test instruments on shared reference legs. These enhancements include requiring pre-pressurization of instrument test lines during the surveillance testing and also revising STP 3.3.3.2-09B to identify the manipulation of shared reference leg isolation valves as critical steps. Additionally, the licensee has implemented corrective actions to improve the Apprenticeship Training Program for I&C Technicians. The finding was determined to be more than minor because the finding was associated with the Initiating Events Cornerstone attribute of Human Performance and affected the cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during power operations. Specifically, the failure to fully isolate the Reactor Vessel Pressure Transmitter from the Reactor Vessel Level Instruments installed on the shared reference leg as required by the STP resulted in an unplanned reactor scram. The inspectors determined the finding was of very low safety significance (Green) because the finding only resulted in a reactor scram and did not contribute to the likelihood that mitigation equipment or functions would not be available. This finding has a cross-cutting aspect in the area of Human Performance, Work Practices, because the licensee did not use human error prevention techniques commensurate with the risk of the assigned task and personnel proceeded in the face of uncertainty. Specifically, an I&C technician failed to complete a step of STP 3.3.3.2-09B when the technician encountered difficulty in shutting the instrument isolation valve for a Reactor Vessel Pressure Transmitter. After several attempts to shut the isolation valve followed by a discussion with a peer, the I&C technician then proceeded in the face of uncertainty and caused a reactor scram. (H.4(a)he face of uncertainty and caused a reactor scram. (H.4(a)
23:59:59, 31 December 2009 +
23:59:59, 31 December 2009 +
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>.
05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 +, 05000331/FIN-2009005-02 + and 05000331/FIN-2009005-02 +
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>.
00:33:27, 29 October 2017 +
23:59:59, 31 December 2009 +