05000250/FIN-2007006-02
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Finding | |
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| Title | Halon System in FZ 108A |
| Description | The team identified a noncompliance with 10 CFR 50, Appendix R, Section III.G.2.c, in that the automatic fire suppression system required by this part for FZ 108A did not have the capability to suppress fires due to the swapping of flexible piping between Halon storage bottles and the protected area. The Halon piping was restored to correct alignment during the inspection. Pursuant to published NRC policy for plants with fire protection programs in transition to NFPA 805 enforcement discretion was exercised. FZ 108A and 108B are each protected by Halon 1301 fire suppression systems which should be designed in accordance with NFPA 12A - 1980, Halon 1301 Fire Extinguishing Systems. These systems are automatically actuated by cross-zoned fire detection systems. The systems were initially designed to provide a 6 percent (by volume) Halon concentration with a hold time of 30 minutes. After further licensee review of the Control Building heating ventilating and air conditioning (HVAC) system operational line-up and potential room leakage issues, the design basis concentration for these areas was changed to provide a 5 percent Halon concentration with a hold time of 10 minutes. These areas primarily contained electrical equipment located in metal cabinets with a limited amount of cable routed in cable trays. The team requested the licensee provide the concentration discharge test reports for these areas to confirm that a 5 percent Halon concentration could be maintained for a hold time of 10 minutes. The team noted that the Control Building ventilation system would remain in operation while the closure of fire dampers would be relied upon to hold the Halon 1301 concentration within the protected room. When it was found that licensee discharge testing had not been performed during system installation, the team requested all engineering documentation that would demonstrate that the required design concentration could be achieved and maintained for the committed hold time period. Further, the team requested that the licensee confirm the quantity of Halon in the bottles connected to the system, so that it could be compared to the data sheet provided by the vendor. As a result of this inquiry, the licensee determined that the Halon bottles for FZ 108A and 108B were misaligned such that the Halon bottle for FZ 108A was connected to Halon system 108B and visa versa. Because FZ-108A is larger than FZ-108B, less than the expected quantity of Halon could be discharged into FZ-108A. Applying formula 2-5.2 from NFPA 12A assuming a room volume of 9,625 cubic feet and a quantity of Halon injected of 221 pounds, the team calculated the initial concentration of Halon in the misaligned configuration would be about 5.55 percent. Licensee calculations assuming the correct alignment of bottles showed that approximately 0.5 percent of the initial concentration would be lost over 10 minutes due to leakage through openings in the envelope of the protected space (such as under doors and through dampers). This calculated 0.5 percent loss in concentration was due to the relative greater density of Halon gas as compared to air. However, it did not account for the additional inflow of fresh air that would leak past nominally closed dampers due to the fact that HVAC fans would continue to run to supply air to other rooms in the control building. Therefore, the team concluded that the misaligned system could not supply sufficient Halon to meet the 10 minute soak time at 5 percent concentration. The apparent cause for the misaligned Halon bottles is attributable to human error, lack of clear procedural guidance and insufficient equipment labeling. The licensee generated a CR and declared the FZ-108A and FZ-108B Halon systems degraded and stationed fire watch personnel in accordance with fire protection compensatory requirements. |
| Site: | Turkey Point  |
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| Report | IR 05000250/2007006 Section 1R05 |
| Date counted | Mar 31, 2007 (2007Q1) |
| Type: | Violation: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | D Payne J Quinones L Bradford M Thomas P Fillion B Melly |
| INPO aspect | |
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Finding - Turkey Point - IR 05000250/2007006 | |||||||||||||
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Finding List (Turkey Point) @ 2007Q1
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