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The inspectors reviewed a self-revealing n … The inspectors reviewed a self-revealing noncited violation of Technical Specification 5.4.1.a, Procedures, after maintenance on power range nuclear instrument N41 resulted in an unanticipated plant transient. On October 6, 2009, the licensee performed Procedure ISL-SE-00N41 to calibrate power range nuclear instrument N41. During performance of the test, control rods unexpectedly inserted ten and a half steps at a rate of 72 steps per minute. The negative reactivity that was inserted due to the inward rod motion caused reactor power to drop approximately one percent power and pressurizer pressure to drop from 2235 psig to approximately 2223 psig. Subsequent review by the licensee determined that the cause of the undesired rod motion was the rod bank selector switch being left in auto rather than other than auto as required by the procedure. The licensee initiated Callaway Action Request 200908596 to address the causes of the unanticipated plant transient. This finding was determined to be greater than minor because it impacted the Initiating Events Cornerstone attribute of human performance and affected the cornerstone objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions. Using Manual Chapter 0609.04, Phase 1 - Initial Screening and Characterization of Findings, this finding was determined to be of very low safety significance since it did not affect the technical specification limit for reactor coolant system leakage or mitigation systems safety function, did not contribute to both the likelihood of a reactor trip and mitigation equipment or functions not being available, and did not increase the likelihood of a fire or internal/external flooding. This finding has a crosscutting aspect in the area of human performance associated with the work practices component because the reactor operator who failed to place the rod bank selector switch into the procedurally required position failed to use human error prevention techniques, such as self- and peer-checking (H.4(a)s, such as self- and peer-checking (H.4(a)

Discovered date

23:59:59, 31 December 2009 +

Docket

05000483 +

Equipment trip

Reactor Trip +

Event date

23:59:59, 31 December 2009 +

Finding integer

3 +

Finding type

Non-cited violation +

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QA.4 +

IR 05000483/2009005 +

Inspector

Geoffrey Miller +, G Guerra +, M Peck +, David Dumbacher +, Paul Elkmann +, Jeremy Groom + and Jim Melfi +

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>.

00:37:03, 29 October 2017 +

Person