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A finding of very low safety significance … A finding of very low safety significance (Green) for failure to implement work instructions for an engineering change to the Integrated Control System (ICS) was self-revealed when Unit 2 lost control of reactor vessel level on September 14, 2013, requiring insertion of a manual scram. The cause of the loss of level control was determined to be a coding error in the ICS that resulted in the improper transition of feedwater control modes during a reactor shutdown. PPLs immediate corrective actions included entering the issue into their corrective action program (CAP) as condition report 1746169, correcting the coding error, and performing and extent of condition review of the ICS code to ensure no additional errors were present. The performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Initiating Events cornerstone and affected its objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the failure to implement work instructions associated with the engineering change resulted in an ICS logic code error which caused a loss of reactor feed requiring a manual reactor scram. The inspectors evaluated the finding in accordance with IMC 0609, Appendix A, The SDP for Findings At-Power, Exhibit 1 for the Initiating Events cornerstone. The inspectors determined the finding was of very low safety significance (Green) because it did not cause both a reactor trip and the loss of mitigation equipment. This finding was determined to have a cross-cutting aspect in the area of Human Performance, Work Management because PPL did not implement a process of planning, controlling, and executing work activities such that nuclear safety is the overriding priority, including the identification and management of risk commensurate to the work. Specifically, the work instructions associated with the engineering change lacked the specificity commensurate with the complexity of the work such that it could be accomplished without error.at it could be accomplished without error.

Discovered date

23:59:59, 31 March 2014 +

Docket

05000388 +

Equipment trip

Reactor Trip +

Event date

23:59:59, 31 March 2014 +

Finding integer

2 +

Finding type

Finding +

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Identified by

Self-revealing +

Inspection Manual Chapter

NRC Inspection Manual 0609/Appendix A, The Significance Determination Process (SDP) for Findings At-Power +

Inspection procedure

IP 71153, Event Followup +

Inspection report

IR 05000387/2014002 +

Inspector

J Grieves +, S Hansell +, Frank Arner +, Andrey Turilin +, Tom Hedigan +, Fred Bower +, Travis Daun +, Douglas Dodson + and Beverly Smith +

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>.

12:59:14, 25 September 2017 +

Person