05000321/FIN-2003006-02
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Finding | |
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| Title | Untimely and Unapproved Manual Operator Action for Post-Fire SSD |
| Description | The team found that a local manual operator action to prevent spurious opening of all eleven SRVs would not be performed in sufficient time to be effective. Licensee reliance on this manual action for hot shutdown during a fire, instead of physically protecting cables from fire damage, had not been approved by the NRC. The team noted that Step 9.3.2.1 of AOP 34AB-X43-001-2, Fire Procedure, Version 10.8, dated May 28, 2003, stated: To prevent all eleven SRVs from opening simultaneously, open links BB-10 in Panel 2H11-P927 and BB-10 in Panel 2H11-P928. The team noted that spurious opening of all eleven SRVs should be considered a large loss of coolant accident (LOCA), and that a LOCA should be prevented from occurring during a fire event to comply with 10 CFR 50, Appendix R, Section III.L.Section III.L requires that, during a post-fire shutdown, the reactor coolant system process variables (e.g., reactor vessel pressure and water level) shall be maintained within those predicted for a loss of normal alternating current power. Having all eleven SRVs opened during a fire would challenge this. Additionally, the team observed that this step was sufficiently far back in the procedure that it may not be completed in time to prevent potential fire damage to cables from causing all eleven SRVs to spuriously open. The licensee had no preplanned estimate of how long it would take operators to complete this step during a fire event. There was no event time line or operator training JPM on this step. The team noted that, during a fire, operators could be using many other procedures concurrent with the Fire Procedure. For example, they could be using other procedures to communicate with the fire brigade about the fire, respond to a reactor trip, deal with a loss of offsite power, and provide emergency classifications and offsite notifications of the fire event. During the inspection, licensee operators estimated that, during a fire event, it could take about 30 minutes before operators would accomplish Step 9.3.2.1. The team concurred with that time estimate which the team had previously determined independently. However, NRC fire models indicated that fires could potentially cause damage to cables in as short a period as five to ten minutes. Consequently, the team concluded that during a fire event, the licensees procedures would not ensure that Step 9.3.2.1 would be accomplished in time to prevent potential spurious opening of all eleven SRVs. The team also identified other issues with Step 9.3.2.1. There was no emergency lighting inside the panels, hence, if the fire caused a loss of normal lighting (e.g., by causing a loss of offsite power), operators would need to use flashlights to perform the actions inside the panels. Consequently, the team considered the emergency lighting for Step 9.3.2.1 to be inadequate (see Section 1R05.07.b). In addition, labeling of the links inside the panels was so poor that operators stated that they would not fully rely on the labeling. Also, the tool that operators would use to loosen and slide the links inside the energized panels was made of steel and was not professionally, electrically insulated. Further, licensee reliance on this operator action, instead of physically protecting the cables as required by 10 CFR 50, Appendix R, Section III.G.2, had not been approved by the NRC. The licensee stated that cable damage to two reactor pressure instrument cables would be needed to spuriously open all eleven SRVs. Because the licensee stated that the two cables were in the same cable tray in Fire Area 2104, the team considered that a fire in that area could potentially cause all eleven SRVs to spuriously open (see Section 1R21.01.b). In response to this issue, the licensee initiated CR 2003008203 and promptly revised the Fire Procedure before the end of the inspection, moving the actions of Step 9.3.2.1 to the beginning of the procedure. The procedure change enabled the actions to be accomplished much sooner during a fire in the Unit 2 east cableway or in other fire areas that were vulnerable to the potential for spuriously opening all eleven SRVs. The team determined that this issue is related to associated circuits. As described in NRC IP 71111.05, Fire Protection, inspection of associated circuits is temporarily limited. Consequently, the team did not pursue the cable routing or circuit analysis that would be necessary to evaluate the possibility, risk, or potential safety significance of Group B and C SRVs spuriously opening due to fire damage to the instrument cables. The team did, however, perform a circuit analysis of Group A SRVs for which the licensee takes credit during a fire in Fire Area 2104. |
| Site: | Hatch  |
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| Report | IR 05000321/2003006 Section 1R04 |
| Date counted | Sep 30, 2003 (2003Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.04 |
| Inspectors (proximate) | C Smith K Sullivan R Schin G Wiseman C Oglec Castod Simpkins J Hickey M Widmann N Staples |
| INPO aspect | |
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Finding - Hatch - IR 05000321/2003006 | |||||||||||||
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Finding List (Hatch) @ 2003Q3
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