The team identified a Green noncited violation of Unit 1 License Condition 2.G. Specifically, the fire suppression systems installed in Fire Zones SE16 and SE18 (remote safety related panels/Train B switchgear rooms) were not installed in accordance with the approved
fire protection program. Description. The fire suppression systems in Fire Zones, SE16 and SE18 are manually actuated dry pipe deluge (preaction) systems with closed sprinkler heads. During plant walkdowns, the team noted that the fire suppression systems did not provide protection in the vicinity of one train of
safe shutdown cables. These
safe shutdown cables were protected by 1-hour
fire barriers, so they are required by the
fire protection program to have fire suppression coverage. The team also noted that the configuration of the fire suppression systems in Fire Zones SE16 and SE18 did not meet the requirements of
NFPA 13 and 15. Section 6.3.5 of Section II of the Fire Protection Report stated that manually actuated preaction sprinkler systems are installed to provide floor area and/or concentrated cable tray coverage in the electrical equipment rooms and cable spreading rooms, including Fire Zones SE16 and SE18. This section also stated that the water suppression systems would be installed in accordance with
NFPA 13 or 15. The NRC approved these suppression systems with less than full area coverage based on the configuration described and evaluated in Calculation 0210-63-0064. Circuits required for
safe shutdown are routed through Fire Zones SE16 and SE18 in cable trays and conduits protected by 1-hour
fire barriers. The supports for these cable raceways are unprotected. The team identified that the installed configuration of the fire suppression systems in Fire Zones SE16 and SE18 do not provide coverage in the areas of cable raceways protected with 1-hour
fire barriers and their unprotected supports as required be the approved
fire protection program. Additionally, the partial coverage manually actuated suppression systems do not meet
NFPA codes, which would be another method of compliance. The licensee entered this finding into its corrective action program under Smart Form SMF-2008-000324-00. Analysis: Failure to ensure that the installed fire suppression systems meet the requirements of the approved
fire protection program was a performance deficiency. The team determined that this deficiency was more than minor because it is associated with the Protection Against External Factors attribute of the
Mitigating Systems Cornerstone and could affect the availability, reliability, and capability of systems that respond to fire events to prevent undesirable consequences. The team used Manual Chapter 0609, Appendix F, Fire Protection
Significance Determination Process and evaluated the finding under the fixed fire protection systems category with a high degradation rating. The circuits in Fire Zones SE16 and SE18, which are required for post-fire
safe shutdown are routed in cable raceways protected by 1-hour
fire barriers with unprotected supports, and do not have sprinkler coverage. In completing the fire protection
Significance Determination Process, Phase 1 and 2 worksheets, the team determined that no potential ignition source could potentially have a direct impact on the protected cable raceways or their supports. The team determined that the largest potential ignition sources in the fire zones could not form a hot gas layer sufficient to impact the protected cable raceways or their supports using the spreadsheet, Predicting Hot Gas Layer Temperature in a Room Fire With Forced Ventilation, contained in
NUREG-1805, Fire Dynamics Tools (
FDT) Quantitative Fire Hazard Analysis Methods for the U.S. Nuclear Regulatory Commission Fire Protection Inspection Program. Based on these evaluations, the finding screened as having very low safety significance (Green) during the Phase 2 significance determination. Enforcement: License Condition 2.G for Unit 1 states, in part, that the Luminant Generation Company
LLC shall implement and maintain in effect all provisions of the approved
fire protection program as described in the Final Safety Analysis Report through Amendment 78 and as approved in the safety evaluation report (
NUREG-0797) and its supplements through Supplemental Safety Evaluation Report 24. The approved
fire protection program included the installation of fire suppression systems with less than full area coverage in some areas of the plant, including Fire Zones SE16 and SE18, as documented in Supplemental Safety Evaluation Report 21. The partial area suppression systems were accepted by the NRC staff based on the system configurations and fire area evaluations provided in Calculation 0210-063-0064, Partial Sprinkler Coverage Evaluation. Contrary to the above, the licensee failed to implement the provisions of the approved
fire protection program. Specifically, the partial coverage fire suppression systems installed in Fire Zones SE16 and SE18 did not provide coverage as approved by the NRC, and are also not in compliance with
NFPA 13 and 15. Because this finding is of very low safety significance and has been entered into the corrective action program, this violation is being treated as a noncited violation, consistent with Section VI.A of the NRC Enforcement Policy:
NCV 05000445/2008006-03, Inadequate Fire Suppression Systems
