ML112000528

EA-11-047, Millstone Regulatory Conference-July 19, 2011 NRC Slides

ML112000528
Person / Time
Site:	Millstone
Issue date:	07/19/2011
From:	- No Known Affiliation
To:	NRC Region 1
McLaughlin M
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EA-11-047
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Millstone Regulatory Conference Summary of Appendix M Attributes Protecting People and the 1 Environment

Finding Details Multiple Examples of Procedural Violations and Inadequate Procedures Relating to Control Room Crew Performance During g a Plant Transient Poor reactivity management Failure to carry out assigned roles and responsibilities Protecting People and the 2 Environment

Appendix M Significance Defense in Depth Inappropriate reactivity control / Lack of caution related to unexpected plant responses:

Repeated operation of turbine controls when response p not as expected p

Manually re-opening a turbine bypass valve that automatically closed Manually pulling control rods to raise RCS temperature On-going RCS dilution Protecting People and the 3 Environment

Appendix M Significance Safety Margin Resetting the variable high power trip during unplanned power increase No procedure to provide guidance for VHT reset during g unexpected p p plant transient Untimely corrective action to provide written procedural guidance.

Repeated VHT reset actions were not communicated to control room team.

VHT resets performed by Reactivity SRO, who was assigned to supervise board manipulations.

Protecting People and the 4 Environment

Appendix M Significance Extent of Condition Extent of condition included other Unit 2 operating crews Post-event observations documented a number of instances of improper p p control room p performance by y

other crews (RCS dilution error)

Inconsistent application of control room standards (alarm response, panel walkdowns)

Protecting People and the 5 Environment