05000390/FIN-2012004-01
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Finding | |
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| Title | Lack of Ability to Execute Flood Mode Configuration within the Time Frame Required by the Technical Requirements Manual, Section 3.7.2, Flood Protection Plan |
| Description | Inspectors identified an unresolved item related to Technical Requirements Manual 3.7.2, Flood Protection Plan. This requirement specifies communications between the licensee and the TVA River Operations organization and time frames for these communications. Based on these communications, which are broken up into Stage I and Stage II, the licensee is required take actions. Stage I activities are essentially preparatory in nature for the plant site to receive flooding levels above plant grade. These include shutting down the reactor and commencing cool-down to 350 degrees and movement of equipment. These Stage I activities are to be complete within 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> of the determination that Stage I should be implemented. Based on communications with River Operations, the licensee remains in Stage I until River Operations determines that flood levels may reach plant grade level. At this point, Stage II is entered where significant plant system realignments occur including connecting the essential raw cooling water (ERCW) system to the component cooling system (CCS) system, ERCW to the raw cooling water (RCW) system, the Fire Protection system to the auxiliary feedwater (AFW) system and in some plant conditions, spent fuel pool (SFP) cooling to the residual heat removal (RHR) system. These connections are made with spool-pieces that are staged at various locations throughout the plant. Stage II activities are to be completed within 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />. Inspectors observed the licensee simulating installation of the spool-pieces utilized to implement AOI-7.01. Based on the observation of the tools, procedures and manpower requirements, the inspectors questioned if the licensee would be successful at reconfiguring the plant within the 17-hour window, and therefore the total time of Stage I plus Stage II activities may exceed the assumed 27 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br />. Initial efforts at integrating these observed maintenance procedures within the master AOI-7.1 Maximum Probable Flood, yielded a time of approximately 39 hours4.513889e-4 days <br />0.0108 hours <br />6.448413e-5 weeks <br />1.48395e-5 months <br />. With input from the field and improved resource loading, sequencing of the support procedures over a three-day effort, the time was reduced to 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> and 37 minutes. With additional focus, based on previous field demonstration of one particular supporting procedure, MI-17.021, Installation of Spool-pieces Between ERCW and Component Cooling Systems, the time was reduced to 27 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br /> and 34 minutes. This was accomplished by assigning two maintenance teams working in parallel on the two largest, heaviest spool-pieces. A further reduction in the time requirements of AOI-7.10, Flood Mode Electrical Systems Alignment, by working parallel teams on the four shutdown boards versus in series yielding a time reduction to 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> and 57 minutes. Excluded from these times was the manpower that would have been required to build a temporary wall protecting the thermal barrier booster pumps (TBBP), which is approximately 4 people for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />. This TBBP modification, although currently installed as of August 2012, would have been required to be built as part of the licensees flood mitigation strategy. Additionally, the two largest spool-pieces were relocated to make installation faster. The time saved by repositioning these spool-pieces would also be added to the above total times to achieve a realistic estimate of the time needed for the all required flood mode mitigation measures to be implemented. The Watts Bar Final Safety Analysis Report (FSAR), Section 2.4.14.4.3 says the following: The steps needed to prepare the plant for flood mode operation can be accomplished within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of notification that a flood above plant grade is expected. An additional 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> are available for contingency margin. Based on NRC observation of the aggregate activities and time frames needed to implement adequate flood protection measures as described in the FSAR, the licensee may not be able to demonstrate an acceptable capability in the required time. The ability of the licensee to perform these activities in the time allotted by the Technical Requirements Manual may not have been assured given the number of days of refinement required by the licensee to reduce the time to 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> and 57 minutes. Compounding the issue is the fact that not all of the activities that would have been required, specifically building the TBBP temporary barrier and relocating two of the spool-pieces, were included in the estimated time. Currently, based on the licensees refinements in their flood protection implementation plan involving more effective resource allocation and job planning, installation of the TBBP temporary barrier, and relocation of key spool-pieces, the licensee has calculated their ability to adequately prepare for a flood event. NRC evaluation of the licensees ability to implement a successful flood protection plan prior to the refinement in the flood mode protection implementation plan requires further response from the licensee as to how they could have previously met this requirement. Pending additional information from the licensee which can verify the timeliness of the licensees ability to reconfigure the plant for flood mode operation URI 050000390/2012004-01, Lack of Ability to Execute Flood Mode Configuration within the Time Frame required by the Technical Requirements Manual, Section 3.7.2, Flood Protection Plan, was identified. |
| Site: | Watts Bar  |
|---|---|
| Report | IR 05000390/2012004 Section 1R01 |
| Date counted | Sep 30, 2012 (2012Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.01 |
| Inspectors (proximate) | R Monk S Shaeffer A Nielsen R Hamilton G Kuzo J Hamman M Coursey K Miller W Pursleyr Monks Shaeffer K Miller |
| INPO aspect | |
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Finding - Watts Bar - IR 05000390/2012004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Watts Bar) @ 2012Q3
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