05000461/LER-2013-006
| Clinton Power Station, Unit 1 | |
| Event date: | 10-13-2013 |
|---|---|
| Report date: | 12-11-2013 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| LER closed by | |
| IR 05000461/2013005 (11 February 2014) | |
| 4612013006R00 - NRC Website | |
PLANT AND SYSTEM IDENTIFICATION
General Electric — Boiling Water Reactor, 3473 Megawatts Thermal Rated Core Power Energy Industry Identification System (EllS) codes are identified in text as [XX].
EVENT IDENTIFICATION
Implementation of Enforcement Guidance Memorandum (EGM) 11-003, Revision 1
A. CONDITION PRIOR TO EVENT:
Unit: 1 Event Date: 10/13/13 Event Time: 0340 hours0.00394 days <br />0.0944 hours <br />5.621693e-4 weeks <br />1.2937e-4 months <br /> CDT Mode: 5 Mode Name: Refueling Reactor Power: 0 percent
B. DESCRIPTION OF EVENT:
While in Mode 5, Refueling, OPDRV's were performed as part of the Unit 1 C1R14 Refueling Outage without an operable secondary containment. The event timeline is as follows:
10/13/2013 03:40 — Commenced OPDRV activity under the provisions of EGM 11-003, Revision 1.
10/13/2013 to 10/27/2013 — Performed OPDRV activities in support of C1R14.
The station used the provisions of EGM 11-003, Revision 1 to perform the following outage activities:
- Reactor Water Cleanup (RWCU) suction line local leak rate testing (LLRT) and subsequent system fill
- Shifting RPV level control to Residual Heat Removal (RHR)
- Hydraulic Control Unit riser vent valve 1C11-1F101 replacement for mechanism 32-53
- SRM B dry tube replacement
- Control Rod Drive (CRD) mechanism exchange (de-torque to re-torque)
- RHR shutdown cooling valves, 1E12F008 and 1E12F009, Category A leak rate testing and LLRTs and subsequent system fill
- Startup of RHR A for shutdown cooling operations
C. CAUSE OF EVENT:
Implementation of EGM 11-003, Revision 1 interim actions during C1R14 Refueling Outage was a planned activity. As such, no cause determination was performed for the events.
D. SAFETY ANALYSIS:
This event is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as an operation prohibited by CPS Technical Specification 3.6.4.1, Secondary Containment, which prohibits performing activities identified as OPDRV's in Mode 5 with secondary containment inoperable.
The OPDRV activities described in this report were accomplished using the interim actions provided by the NRC in EGM 11-003, Revision 1. CPS adhered to the NRC plain language meaning of OPDRV activities that could potentially result in draining or siphoning the RPV water level below the top of the fuel. This included evolutions involving aligning and realigning plant systems prior to achieving steady-state water level control, without taking credit for mitigating measures. CPS also met the requirements which specify the minimum makeup flow rate and water inventory. Further, an adequate defense in depth was maintained to minimize the potential for the release of fission products with secondary containment inoperable. Since these measures were implemented, an adequate level of safety was provided during the performance of the OPDRV activities described in this report.
E. CORRECTIVE ACTIONS:
CPS will submit a license amendment request following NRC approval of the Technical Specification Task Force (TSTF) traveler associated with generic resolution of this issue within the time constraints specified in EGM 11-003.
F. PREVIOUS OCCURRENCES:
None.
G. COMPONENT FAILURE DATA:
Not applicable.