ML120720409

Email, Request for Additional Information, Amendment Request to Revise Technical Specification 3.3.8.1, Loss of Power Instrumentation, to Extend Frequency of SR 3.3.8.1.3 / Revise Allowable Values for Certain Functions

ML120720409
Person / Time
Site:	River Bend
Issue date:	03/12/2012
From:	Wang A Plant Licensing Branch IV
To:	Burmeister B, Clark J, Williamson D, Wang A Entergy Operations, Office of Nuclear Reactor Regulation
Wang, A B, NRR/DORL/LPLIV, 415-1445
References
TAC ME7767
Download: ML120720409 (2)

Text

From: Wang, Alan Sent: Monday, March 12, 2012 1:03 PM To: Wang, Alan; 'BURMEISTER, BARRY M'; 'Joseph Clark (JCLARK@entergy.com)';

WILLIAMSON, DANNY H Cc: Burkhardt, Janet; Lent, Susan

Subject:

River Bend Station, Unit 1 (RBS) Request for Additional Information Regarding Degraded Voltage Surveillance Frequency Extension TS Change (ME7767)

Barry, Danny and Joey, By letter dated December 8, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML11349A246), Entergy Operations, Inc (Entergy, the licensee) submitted Entergy Letter RBG-47193, License Amendment Request 2011-05 Degraded Voltage Surveillance Frequency Extension and Allowable Value Changes. In this letter, Entergy submitted a request to extend the frequency of Surveillance Requirement (SR) 3.3.8.1.3 (calibration of loss of power instrumentation) from 18 to 24 months and revise certain allowable values in TS 3.3.8.1, Loss of Power Instrumentation.

The NRC staff has determined that the following additional information is needed to complete our review. This request was discussed with Mr. Danny Williamson of your staff on March 12, 2012, and it was agreed that a response would be provided within 30 days from the issuance of this email. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1445 or via e-mail at Alan.Wang@nrc.gov. .

This amendment request proposes revisions to the loss of voltage setpoint allowable values and Degraded Voltage Time Delay (No LOCA) allowable values in Technical Specification (TS)

Table 3.3.8.1-1. Following questions pertain to changes to the setpoint allowable values:

1. In section 3.2 of the license amendment request (LAR) the licensee states:

Because all Class 1 E motors were purchased to be capable of starting and accelerating their driven equipment with motor terminal voltages of 70 or 80 percent of motor nameplate voltage without affecting performance or equipment life, no operability concerns exist for any equipment. However, a group of the motor operated valves (MOVs) governed by GL 89-10 was determined to have insufficient voltage to pick up their torque switch, allowing potential failure after reaching their safety position. Thus, although the valves maintain their operability, full functionality was not maintained under existing analysis. To bring the valves back to full functionality, River Bend Station used the results of the offsite grid stability studies and modified the offsite power requirements to ensure that grid voltage is no lower than 97.5%, up from the current limit of 95%.

a. Provide a brief summary of the evaluation that demonstrates that all Class 1E motors have adequate starting and running voltages based on the setpoint values specified in TS Table 3.3.8.1 rather than higher voltage shown on the grid stability study. Verify that protective devices such as relays, thermal overloads, fuses and contactors will not actuate during the start sequence.

b. Provide details on how the grid voltage is maintained at or above 97.5%. If grid operator actions are required, then validate that MOVs will remain functional and perform their intended safety functions with the safety bus

voltages at the degraded voltage relay set point as specified in TS Table 3.3.8.1.

c. Verify that plant modifications and replacement equipment installed since the original plant construction have maintained 70 or 80 percent minimum voltage operating requirements.

Alan Wang Project Manager (River Bend Station)

Nuclear Regulatory Commission Division of Operating Reactor Licensing