RS-09-155, Clarification Regarding License Amendment Request for a One-Time Extension of the Essential Service Water Train Completion Time
| ML093200065 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 11/13/2009 |
| From: | Simpson P Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-09-155 | |
| Download: ML093200065 (2) | |
Text
Exelon Cenerat~on 4300 W~nfield Road Nuclear RS 1 55 November 13,2009 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455
Subject:
Clarification Regarding License Amendment Request for a One-Time Extension of the Essential Service Water Train Completion Time
Reference:
Letter from P. R. Simpson (Exelon Generation Company, LLC) to U. S. Nuclear Regulatory Commission, "License Amendment Request for a One-Time Extension of the Essential Service Water Train Completion Time," dated September 24, 2009 In the Reference, Exelon Generation Company, LLC, (EGC) requested a license amendment for Byron Station, Units 1 and 2, for a one-time extension of the Completion Time (CT) to restore a unit-specific SX train to operable status associated with Technical Specifications (TS) Limiting Condition for Operation (LCO) 3.7.8, "Essential Service Water (SX) System," from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br />. This proposed change will only be used one time during the Byron Station Unit 2 spring 2010 refueling outage (i.e., B2R15). of the Reference provides the supporting risk-informed evaluation of the proposed change. Provided in Section 2.3.2.2 of Attachment 5 is a risk evaluation of the impact of the SX outage on the key shutdown safety functions: Reactivity Control, Shutdown Cooling, lnventory Cooling, Fuel Pool Cooling, Electric Power Control, Containment, and Vital Support Systems.
Section 2.3.2.2 of Attachment 5 describes, in part, the impact of the SX outage on the Inventory Control function as follows:
The inventory control requirements consist of optimizing the RH, SI, and CV train availability at all times during the outage except when the core is completely offloaded.
The lnventory Control function is no longer applicable when the core is completely offloaded; hence, there is no need to maintain the residual heat removal (RH), safety injection (SI) and chemical and volume control (CV) systems available for that function. For clarification, the phrase regarding availability, "except when the core is completely offloaded," also applies to the Reactivity Control and Shutdown Cooling functions for the same reasons. Although this is implied within the description of the two functions, this letter is intended to provide this clarification.
November 13,2009 U. S. Nuclear Regulatory Commission Page 2 EGC has reviewed the information supporting a finding of no significant hazards consideration that was previously provided to the NRC in the Reference. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration.
There are no regulatory commitments contained in this letter.
Should you have any questions concerning this letter, please contact Ms. Lisa A. Schofield at (630) 657-281 5.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 13th day of November 2009.
idMlt&-\\
Patrick R. Simpson Manager - ~ i c e n s i n ~ 0 Exelon Generation Company, LLC cc:
NRC Regional Administrator, Region Ill NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station