05000341/FIN-2007006-07
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Finding | |
|---|---|
| Title | NON-QUALIFIED TY-WRAPS Inside Primary Containment |
| Description | The inspectors noted the use of Tefzel ty-wraps inside primary containment and, due to their abundance, the inspectors questioned the licensee about their tracking program for items that could become debris in the torus and potentially block the ECCS and RCIC pump suctions. The licensee stated the design specification did not cover the use of ty-wraps in the drywell. Upon further investigation, the licensee identified that the lead shielding installed during a previous outage had not been considered in the design specification. The inspectors reviewed specification 3071-389, Revision 3, Emergency Core Cooling System Suction Strainers, and noted that ty-wraps were not addressed in the specification. When questioned by the inspectors, the licensee stated the only program in place was to track paint in the drywell and torus. Upon further review, the licensee noted shield blankets had been installed in the drywell without modeling the debris loading on the strainers. The licensee-performed walkdowns revealed a total of 36 ft2 of ty-wraps inside the drywell. The licensee removed 20.6 ft2 of ty-wraps from the drywell following the walkdowns. Engineering personnel performed Engineering Functional Analysis (EFA) E11-07-0005, Revision A, Non-Qualified, Tefzel Ty-Wraps Inside Primary Containment, to analyze the effects of the remaining ty-wraps and the shield blanket debris on ECCS and RCIC suction from the torus. This analysis included the potential for the ty-wraps to be carried into the strainers via the torus for several different accident scenarios. The strainer hydraulic analysis performed in the EFA allowed for an increase in the load from fibrous debris and included the lead wool and ty-wraps. The evaluation concluded that only 7.1 ft2 of ty-wraps were available for transport to the strainers, which was less than the maximum allowable load of 13.75 ft2. For the design limiting case, the RHR and Core Spray pumps would have sufficient net positive suction head available thereby alleviating current safety concerns. Resolution of the past operability concern will be provided by incorporating the remaining material in the drywell into the plant design bases associated with strainer loading and the establishment of a program for control of materials inside containment. Pending further analysis of past operability by the licensee of whether the use of nonqualified Tefzel ty-wraps inside primary containment could have plugged the strainers, this is considered an Unresolved Item. URI 05000341/2007006-07: Non-Qualified Ty-Wraps Inside Primary Containment. |
| Site: | Fermi  |
|---|---|
| Report | IR 05000341/2007006 Section 1R20 |
| Date counted | Dec 31, 2007 (2007Q4) |
| Type: | URI: |
| cornerstone | No Cornerstone |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.2 |
| Inspectors (proximate) | T Steadham D Reeser M Bielby M Franke R Morris A Wilson R Lerch K Barclay A Muniz C Lipa J Moore K Streit M Holmberg M Munir R Jickling J Cassidyj Cassidyj Jacobson T Steadham J Rutkowski R Morris J Giessner F Tran E Martinez |
| INPO aspect | |
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Finding - Fermi - IR 05000341/2007006 | |||||||||||||||||||||||||||||||||
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Finding List (Fermi) @ 2007Q4
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