RS-13-164, Clarification Regarding the Testing Frequency for Fifth Inservice Testing Interval Relief Request RV-23H
| ML13165A205 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/13/2013 |
| From: | Simpson P Exelon Generation Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RS-13-164, TAC ME9872 | |
| Download: ML13165A205 (2) | |
Text
4300 RS-1 3-164 June 13, 2013 10 CFR 50.55a ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249
Subject:
Clarification Regarding the Testing Frequency for Fifth Inservice Testing Interval Relief Request RV-23H (TAC No. ME9872)
References:
1.
Letter from P. R. Simpson (Exelon Generation Company, LLC (EGC)) to U. S. NRC, "Submittal of Relief Requests Associated with the Fifth Inservice Testing Interval," dated October 30, 2012 2.
Letter from P. R. Simpson (EGC) to U. S. NRC, " Response to Request for Additional Information Related to Request for NRC Approval of Relief Requests for Fifth Inservice Testing Interval (TAC Nos. ME9871 and ME9872)," dated April 1, 2013 In Reference 1, EGC requested approval of relief requests associated with the upcoming fifth IST Interval at Dresden Nuclear Power Station (DNPS), Units 2 and 3.
While reviewing Reference 1, the NRC found that additional information was required to support its review. The requested information was provided in Reference 2.
During a telephone conversation between the NRC and EGC personnel on June 4, 2013, NRC personnel requested that EGC provide an additional clarification related to the testing frequency for DNPS, Units 2 and 3 High Pressure Coolant Injection (HPCI) valves 2(3)-2301-32-SO.
Specifically, in Relief Request RV-23H as submitted in Reference 1, EGC stated that 2(3)-2301-32-SO will be exercised quarterly using the handswitch, and that they will also be tested each refueling outage by filling the drain pot and verifying that the valves actuate as indicated by the high level alarm clearing. In the response to NRC Question RAI-RV-23H-2 provided in Reference 2, EGC stated, "A semi-annual exercise of the 2(3)-2301-32-SO valves is currently performed and its associated level switches operate as proven by the receipt of the
'HPCI TURBINE EXH DRAIN POT HIGH LEVEL' alarm (i.e., water level increase) and reset (i.e., water level decrease due to the open exercise of valves 2 (3)-2301-32-SO)."
June 13, 2013 U. S. Nuclear Regulatory Commission Page 2 For the sake of clarity, EGC currently performs the semi-annual testing of DNPS, Units 2 and 3 HPCI valves 2(3)-2301-32-SO described in Reference 2 every six months, in addition to the quarterly exercise test and the functional test performed during each refueling outage as described in Reference 1.
Since the semi-annual testing and refueling outage testing both entail filling the HPCI drain pot, cycling 2(3)-2301-32-SO as verified by the resetting of the associated high level alarm, and verification that the valve solenoid energizes through ensuring a small metallic object is attracted to the solenoid, EGC intends to discontinue reliance on the functional test performed during each refueling outage. The first paragraph of Reference 1, Attachment 4, Section 5, "Proposed Alternative and Basis for Use," is superseded with the following paragraph:
These valves will be exercised quarterly using the hand switch. They will also be functionally tested semi-annually (i.e., every six months).
During the semi-annual test valve 2(3)-2301-32 actuation will be verified by the receipt of the "HPCI TURBINE EXH DRAIN POT HIGH LEVEL" alarm (i.e., water level increase) and reset (i.e., water level decrease due to the open exercise of valves 2(3)-2301-32-SO).
During this same semi-annual test, the valve solenoid is also verified to actuate (i.e., valve solenoid is magnetized) by use of a small metallic object. This testing approach provides reasonable assurance that the valves function as required.
Performing the functional test every six months in conjunction with the quarterly exercise test and the disassembly, inspection, repair and or replacement of 2(3)-2301-32-SO every third reactor fuel cycle as described in Reference 1, is sufficient to verify the operational readiness of the valves. Based on the operational history for the valves described in Reference 2, it is not necessary to rely on the refueling outage functional test to verify the operational readiness of these valves. No other changes are proposed to DNPS fifth inservice testing interval Relief Request RV-23H.
There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, or require additional information, please contact Mitchel Mathews at (630) 657-2819.
ReeRectfully, Manager - Licensing Exelon Generation Company, LLC Patrick R. Simpson