05000244/FIN-2013004-01
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Finding | |
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| Title | Design Basis External Flooding and Unsealed Penetrations in the ?B? Battery Room |
| Description | On May 29, 2013, the east and west chambers of manhole 1 were opened to complete Fukushima flooding walkdown inspections of two penetrations. The east and west chambers of manhole 1 are located in the transformer yard on the east side of the plant directly adjacent to the control building. One penetration was between the east chamber of manhole 1 and the B battery room, and the other penetration was between the west chamber of manhole 1 and the B battery room. During this inspection, which focused only on the penetrations, the inspectors and CENG personnel identified that the penetrations appeared to be unsealed and only contained ceramic fiber insulation. By May 31, CENG personnel determined that each chamber of manhole 1 also contained a drain. Condition report (CR)-2013-003407 documented these conditions and documented an assessment that assumed flow into the manhole chambers via the edges around and holes in the manhole covers. This assessment assumed 50.3 gallons per minute (gpm) of flow into each chamber of manhole 1 based on a flood height of 1.73 feet above the outside of the manhole. The assessment assumed that each drain was capable of passing 95 gpm of water. The CR noted that a walkdown of the floor drains was required to verify that the floor drains were as designed and capable of passing the calculation assumed flow rate. The inspectors questioned the preventive maintenance frequency and previous testing of the drains and no licensee records could be located that indicated that the drains had ever been tested or cleaned. The inspectors were subsequently informed that the manhole drain inspections were not planned until October 2. The inspectors noted that Ginna had no definitive plans to seal the penetrations between manhole 1 and the B battery roomonly a potential enhancement action with a due date of December 1, 2014. Because the drains had never been inspected or tested, the inspectors expressed concerns to CENG personnel about the drains being clear and able to pass the assumed flows. On September 5, CENG electricians were performing periodic manhole inspections these inspections check for water in manhole chambers and pump it out, if necessary. The inspectors accompanied the electricians on this inspection. The inspectors captured photographs of substantial debris in both chambers of manhole 1 and both manhole 1 drains. In one chamber, a large sheet of plastic laid on the chamber floor among a layer of mud, rocks, and other debris. Other debris in one or both chambers of the manhole included large and small pieces of wood, 3-inch diameter pieces of foam, tie wraps, large nails and bolts, varying sizes of rocks and stones, rope, large pieces of hard plastic, wire, sticks, and tools. The photographs also documented likely water staining of the cinder block walls in both manhole chambers and significant debris was clearly visible in both drains. These photographs were shared with CENG management on September 5. CR-2013-005262 documented the debris in manhole 1, but stated that the condition could not affect operability of a structure, system, and component (SSC) and that the drain line would pass anticipated flow. The inspectors questioned this assessment and again expressed concern that the drains would not be capable of passing the necessary flow. Ginna took no additional immediate actions. On September 17, CENG personnel were reviewing the photographs that the NRC inspectors provided on September 5 and determined that the manhole drains were missing their covers. At this point, the issue was elevated to a priority two work order (WO). Compensatory measures were also established to check the 5-day weather forecast and maintain plastic covers and sandbags over the manhole covers. Plans to test the drains and clean the manhole chambers were also expedited. Finally, a modification package was created to permanently seal the penetrations between manhole 1 and the B battery room. On September 20, CENG tested the manhole 1 drains to determine the flow rate the drains were capable of passing; neither drain was able to pass the amount of water needed to prevent water accumulation during testing. CR-2013-005643 documented that the drains failed to demonstrate the ability to pass the required flow and noted that the penetrations between manhole 1 and the B battery room would be challenged. CENG management concluded that an unanalyzed condition existed due to unqualified battery room penetrations and partially blocked manhole chamber drains. On September 30, CENG completed modification engineering change package (ECP) 13-000854, Battery Room to Manhole 1 Penetrations Flood Barrier, Revision 0000, which installed permanent seals in both penetrations between manhole 1 and the B battery room; thereby, the flooding concern was addressed. Section 2.4.2.1, Flood Design Considerations, of Ginnas UFSAR states that the plant is protected from a Deer Creek flood at an elevation of 273.8 feet, which is equivalent to a Deer Creek flood of 26,000 cubic feet per second. Section 3.4.1.1.3, Deer Creek Flood Protection, states that a Deer Creek discharge of 26,000 cubic feet per second corresponds to an elevation of 272.0 feet on the north and east side of the plant. This is a flood height of approximately 2 feet in the transformer yard, where manhole 1 is located, because the general plant grade is approximately 270 feet. At the end of the inspection period, CENG personnel were completing an apparent cause evaluation (ACE) focusing on the unqualified penetrations in the B battery room, the clogged manhole 1 drains, and previous opportunities to identify and correct these conditions. CENG personnel were also conducting some additional flooding analyses to determine what, if any, safety-related equipment in the A and B battery rooms would be challenged by a design basis flood via the unqualified penetrations and what, if any, consequences would result. This issue will be opened as a URI in order to review and evaluate CENG new flooding analyses, ACE, and other supporting documentation to determine if a violation exists with respect to the issue of concern of not adequately assessing plant conditions or taking appropriate actions to ensure equipment in the A or B battery room would not be challenged by a design basis flood. |
| Site: | Ginna  |
|---|---|
| Report | IR 05000244/2013004 Section 1R01 |
| Date counted | Sep 30, 2013 (2013Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.01 |
| Inspectors (proximate) | A Rosebrook D Dodson D Schroeder J Laughlin N Perry T Moslak |
| INPO aspect | |
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Finding - Ginna - IR 05000244/2013004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Ginna) @ 2013Q3
Self-Identified List (Ginna)
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