The inspectors identified a Green Non-Cited Violation (
NCV) of Robinsons License Condition 3. E,
Fire Protection Program, for increasing the amounts of in-situ combustibles in several fire zones within fire area A above required limits in NRC approved licensing exemptions. The licensee has entered the finding into the corrective action program as Nuclear Condition Report (NCR) 567284 and established continuous fire watches as well as restricted
transient combustibles permits for the fire areas of concern. The failure to properly evaluate increases in the quantities of in-situ combustibles above those stated as upper limits for anticipated fire severity and duration in HBR2
exemption requests and an associated
SER was a performance deficiency. This performance deficiency was determined to be more than minor because the finding was associated with the protection against external events (i.e. fire) attribute of the
mitigating systems cornerstone objective of ensuring the availability, reliability and capability of systems that respond to external events that prevent undesirable consequences. In seven fire zones upper limits for fire severity were exceeded. Using the guidance contained in the
IMC 0609 Appendix F, the inspectors concluded that a Phase 3 analysis was necessary because the noncompliance involved fires leading to main control room abandonment. The Phase 3 analysis concluded that this item would be associated with a finding of very low safety significance (Green) because the fire detection systems, fire brigade,
fire barriers, and the Dedicated Shutdown Systems were not affected by increase in fire loading in the affected fire areas. The inspectors identified a cross cutting aspect in the decision making component of the human performance area because the licensee did not use conservative assumptions in decision making to demonstrate the proposed action did not affect the validity of the technical basis for granted exemptions.
