05000454/FIN-2015004-06
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Licensee-Identified Violation |
| Description | As discussed in Section 4OA3.1 of this report, the licensee identified through communication of operating experience from Braidwood Station that design deficiencies in the circuits associated with the Pressurizer PORV block valves might have resulted in the valves not being available when required due to fireinduced failures in the event of a fire in the control room, cable spreading rooms, or electrical cable penetration areas. Byron License Conditions 2.C(6) for Unit 1 and 2.E for Unit 2, required, in part, that the licensee implement and maintain in effect all provisions of the fire protection program as described in the FSAR, as supplemented and amended, and as approved in SERs and their supplements. Section 2.4.3.2, Pressurizer PORVs and Block Valves of the Safe Shutdown Analysis, stated, in part, that the Division 12(22) PORV and block valves both have control cables in the main control room and in two of the lower cable spreading rooms. Should a fire in any of these zones cause the spurious opening of the PORV, coincident with control circuit damage to the block valve, the block valve could still be closed. A remote/local isolation switch and control switch are provided for the block valve at its motor control center, located in the Division 12(22) electrical penetration area. The block valve can be closed by placing the remote/local isolation switch in local and then closing the valve with the control switch provided. Additionally, Section 2.4.3.2 also stated that in fire zones where one of the PORVs had a control cable present in the zone that can spuriously open the PORV and its associated block valve does not have AC power available, the PORV will be failed closed by pulling its control power fuse at its DC distribution panel. Contrary to the above, as of August 20, 2015, the licensee failed to implement and maintain all provisions of their approved fire protection program. Specifically, the licensee failed to ensure that control circuits associated with the PORVs and local control function would close the PORV block valve during the postulated fire. The licensee entered this issue into their CAP, established fire watches, and performed plant modifications to correct the issue. The inspectors determined that the issue was more than minor because the performance deficiency impacted the Protection Against External Factors Attribute of the Mitigating Systems Cornerstone in that fire-induced circuit failures could impair the operation of the PORV block valves and complicate shutdown of the plant in the event of a fire in the control room, cable spreading rooms, or electrical cable penetration areas. The finding was determined to be of very low safety significance (Green) based on a detailed risk-evaluation performed by a Region III Senior Reactor Analyst. |
| Site: | Byron  |
|---|---|
| Report | IR 05000454/2015004 Section 4OA7 |
| Date counted | Dec 31, 2015 (2015Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | A Shaikh B Palagi C Thompson G Hansen J Cassidy J Draper J Jandovitz J Mcghee L Smith M Holmberg V Meghani |
| Violation of: | License Condition - Fire Protection License Condition |
| INPO aspect | |
| ' | |
Finding - Byron - IR 05000454/2015004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Byron) @ 2015Q4
Self-Identified List (Byron)
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||