ENS 46964

v t e ENS Event
18:00 Jun 15, 2011
Title	Rosemount Model 710 Trip Units Would Not Turn on During Testing
Event Description	On June 15, 2011, the Site Vice President was notified that the 10 CFR 21 evaluation of Rosemount Model 710 trip units supplied under purchase order 10174727 determined that the reporting criteria of 10 CFR 21.21 (d)(1) are met. During pre-installation testing, it was found that 3 of 4 Rosemount Model 710 trip units would not turn on. The units were returned to Rosemount for failure analysis and it was determined that a resistor in the start-up circuit for the trip unit was failed. This prevented the trip unit from starting. Based on engineering analysis, some of the applications for the trip unit require it to energize to perform the associated safety functions. Therefore, the identified failure mechanism could have represented a substantial safety hazard if the components had been installed, and the condition is reportable. The condition had no actual safety consequences as the deficiency was identified during pre-installation testing and if installed without pre-installation testing, the system could not have passed post maintenance testing. The three failed units were returned to Rosemount. This notification is made pursuant to 10 CFR 21(d)(ii)(3)(i). The licensee notified the NRC Resident Inspector.

ENS 46964 +/-
Where
FitzPatrick New York (NRC Region 1)
Reporting

10 CFR 21.21
Time - Person (Reporting Time:+18.23 h0.76 days <br />0.109 weeks <br />0.025 months <br />)
Opened:	Eugene Dorman 12:14 Jun 16, 2011
NRC Officer:	Pete Snyder
Last Updated:	Jun 16, 2011
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v • d • e

v t e Emergency Notification System
FitzPatrick with 10 CFR 21.21
WEEKMONTHYEAR2011-06-15T18:00:00 [Table view]
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