ENS 49781

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v t e ENS Event
05:00 Jan 31, 2014
Title	Part 21/50.55 - Ap1000 Updated Reactor Coolant Pump Locked Rotor Analysis
Event Description	The following was received via facsimile: The purpose of this letter is to provide the Commission with the prescribed interim report as required per 10 CFR 21.21(a)(2) of a deviation identified by Westinghouse Electric Company LLC. This also will serve as an interim report under 10 CFR 50.55 (3)(ii) to the extent applicable. A postulated reactor coolant pump (RCP) locked rotor (LR) transient has been explicitly analyzed for the AP1000 steam generator (SG) structural design, as documented in the latest AP1000 Design Control Document (DCD), Revision 19. This includes the calculation of LR hydrodynamic forces (HF) on the SG using the BANG UP code. This activity was performed based upon the unique features of the AP1000 design. However, the other AP1000 reactor coolant system (RCS) structural component analyses have not considered the locked rotor transient for hydrodynamic forces, even though a determination has been made that the effects of these loads could be more bounding than the limiting design-basis loss of coolant accident (LOCA) hydrodynamic forces (based on the BANG UP calculation of pressure pulsations through the RCS). Westinghouse has not yet completed its evaluation as to whether there is a reportable condition as defined in 10 CFR 21 (or 10 CFR 50.55 to the extent applicable) if the deviation is left uncorrected. Westinghouse expects to complete this evaluation by September 30, 2014. We will inform the staff if there are any changes to this schedule, prior to that date.

ENS 49781 +/-
Where
Westinghouse Electric Company Cranberry Township, Pennsylvania (NRC Region 1)
Organization:	Westinghouse Electric Company
Reporting

10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component 10 CFR 50.55(e)
Time - Person (Reporting Time:+8.65 h0.36 days <br />0.0515 weeks <br />0.0118 months <br />)
Opened:	James Gresham 13:39 Jan 31, 2014
NRC Officer:	Daniel Mills
Last Updated:	Jan 31, 2014
49781 - NRC Website
v • d • e

v t e Emergency Notification System
Westinghouse Electric Company with 10 CFR 50.55(e), 10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component
WEEKMONTHYEAR2014-01-31T05:00:00 [Table view]
[ENS list for Westinghouse Electric Company]

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