On January 2, 2015, operators implemented a plant barrier impairment (PBI) form to allow installation of a metal beam under the 1A
DG rollup door (0DSSD166) to support work for the planned
DG work window scheduled to begin on January 4. PBI 14400 was created to support
WO 1657636 and identified the type of barrier as a fire, security, and
high energy line break (
HELB) barrier. The PBI also identified the compensatory actions required to be in place when the PBI was implemented in order to satisfy the requirements of
TRM 3.10.g, Fire Assemblies. Barrier impairments were controlled by CCAA201, Plant Barrier Control Program. In the case of this fire door, an
hourly fire watch was specified in the PBI for this barrier, but was not implemented until January 4 when operators recognized the beam was not a qualified
fire barrier. The required
hourly fire watch was not in place for
33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> and 28 minutes after the barrier was impaired. The Byron Unit 1 operating license (NPF37) specified, in part, in Condition 2.C.(22) that Byron would develop and maintain strategies for addressing large fires and explosions considering, in part, minimizing the spread of fire. A key element to that strategy for
fire barriers providing support for a credited safety function identified in the current licensing basis as documented in the Fire Protection Report and implemented in CCAA201 was the Plant Barrier Control Program.
Technical Specification 5.4.1.c requires, in part, that written procedures be implemented and maintained covering
Fire Protection Program Implementation. Contrary to the
TS 5.4.1.c requirements specified above, the requirements of CCAA201 were not implemented to ensure that fire spread would be minimized in accordance with evaluated compensatory measures identified in the PBI and supporting documents. The licensee immediately implemented the required
hourly fire watch when the condition was identified. The issue was entered into the
CAP as
IR 2441189 and support procedures were revised to provide clarifying information regarding barrier impairment for
DG rollup doors. The inspectors determined that this issue was more than minor because the performance deficiency adversely impacted the Design Control attribute of the
Mitigating Systems cornerstone and adversely impacted the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences (i.e., core damage) in that intentional impairment of a design barrier is a modification that adversely impacts the attribute of design control and must be performed in accordance with approved procedures and processes. The inspectors determined the issue was of very low safety significance using
IMC 0609 Appendix F, Fire Protection
Significance Determination Process. The finding was characterized as 1.4.1, Fire Prevention and Administrative Controls. The inspectors answered "Yes" to Question 1.3.1 A and determined that the reactor could be safely shutdown since the vulnerability was limited to one safety train and suppression/detection systems remained functional during the entire period that compensatory measures were not in place.
