05000321/FIN-2006006-01
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Finding | |
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| Title | Local Operator Actions in Lieu of Cable Protection for a Fire Area Subject to the Requirements of III.G.2 |
| Description | The team identified an unresolved item (URI) involving reliance on manual operator actions (MOAs) in lieu of the cable protection required by Appendix R,Section III.G.2. Three examples of this problem applied to Fire Zone FZ 0014K, however the extent of this problem went beyond the fire areas selected for this inspection Use of MOAs is a generic industry issue discussed in Federal Register Notice 71 FR 11169, dated March 6, 2006. Notice 71 FR 11169 provides for enforcement discretion if specified conditions are met. The URI was opened to monitor resolution of the MOA issue and determine whether enforcement discretion can be applied. Description: The licensees strategy for accomplishing post fire SSD for a postulated fire in FZ 0014K utilized three MOAs outside of the MCR which were not approved by the NRC. The MOAs were: Restoring power to division II battery chargers Restoring power to intake structure ventilation Manually opening the RHR low pressure coolant injection (LPCI) inboard discharge valve (1E11-F015B), and closing the RHR pump minimum flow valve (1E11-F018B) The first MOA required the operators to pass through the fire affected area to access panel 1R25-S002, switchgear 1R23-S004, and battery chargers 1R42-S029, 1R42-S030, and 1R42-S031 in compartments which could not be entered without traversing the fire affected area. These actions were required to be performed within two hours of the postulated fire in FZ 0014K. The team performed an evaluation of the fire scenario timeline for a postulated fire in FZ 0014K including: detector response time, suppression system response time, fire brigade response time, FZ combustible loading and potential fire duration, and ventilation system smoke removal capability. The evaluation revealed that the fire would most likely be extinguished and smoke removed in time to permit traversing through the area to accomplish the MOA. The team concluded that the MOA met the criteria of IP 71111.05T for an acceptable compensatory measure. Need for this MOA could result from fire damage to a control cable which would result in a spurious loss-of-voltage signal. The licensee entered this unapproved MOA into the corrective action program in CR 2006100755 and was considering rerouting the affected cabling to eliminate the need for the MOA. The second MOA also required the operators to pass through the fire affected area to access switchgear 1R23-S004 to restore power to intake structure ventilation. Need for this MOA was the fact that a control cable could be damaged resulting in a spurious tripping of the feeder breaker to the motor control center which feeds the ventilation fan. Similar to the MOA described above, execution of this action would have to be delayed until the area was accessible to the operator. The inspectors determined that loss of ventilation could be sustained for this delay time without defeating, or significantly affecting, any shutdown function. The team concluded that the MOA met the criteria of. IP 71111.05T for an acceptable compensatory measure. Furthermore, the FHA/SSA indicated that only one intake structure ventilation fan was required for SSD. In most scenarios, the Unit 2 intake structure ventilation fans would provide the cooling during the time that it would take to allow the operator to access the switchgear passing through the fire affected zone. The team reviewed the routing for Unit 2 intake structure ventilation electrical cables which also traversed FZ 0014K on the opposite side of the FZ from the Unit 1 intake structure cabling and determined that there was not a credible fire which could affect both sides of FZ 0014K and completely eliminate intake structure ventilation. The licensee entered this unapproved MOA into the corrective action program in CR 2006100755 and was considering rerouting the affected cabling to eliminate the need for the MOA. . The third MOA was performed in the reactor building and necessitated manual operation of valves 1E11-F015B and 1E11-F018B. Valve 1E11-F015B is located in a high temperature, poorly lit, potentially contaminated environment over the Unit 1 drywell access. The power to motor operated valve 1E11-F015B was from Unit 2 600 V switchgear bus 2D via Unit 1 MCC R24-S018B. Damage to Unit 2 control cable 2R23- S004-ES8-C02 could necessitate manual valve operation to achieve SSD. Similarly, fire damage to electrical cables could necessitate manual operation of valve 1E11-F018B. The team determined this action was feasible, since a fire in FZ 0014K would not require LPCI immediately, and sufficient time was available to accomplish the manual valve operations. The team concluded that the MOA met the criteria of IP 71111.05T for an acceptable compensatory measure. The licensee entered this MOA into the corrective action program in CR 2006100755 and was considering installing manual transfer switches and alternate power feeds to eliminate the need for this MOA. Analysis: The issue is a performance deficiency, because even though it involves a generic industry issue, the licensee should not have used MOAs in lieu of protecting cables important to safe shutdown from potential fire damage. The performance deficiency is associated with the reactor safety mitigating system cornerstone attribute of protection against external events, i.e., fire. It also affects the cornerstone objective of ensuring reliability of systems that respond to events in that MOAs are less reliable than fixed fire protection features. Enforcement: 10 CFR 50.48(b)(1) requires, in part, that all nuclear power plants licensed to operate prior to January 1, 1979, must satisfy the applicable requirements of Appendix R,Section III.G.Section III.G.2 applies to the ability to achieve and maintain hot SSD from the control room during a fire. It states, in part, that where cables or equipment, including associated non-safety circuits that could prevent operation or cause maloperation due to hot shorts, open circuits, or shorts to ground, of redundant trains of systems necessary to achieve and maintain hot shutdown conditions are located within the same fire area outside of primary containment, one of three means of protecting cables to ensure that one of the redundant trains is free of fire damage shall be provided. The three means involve physical protection or separation of cables to preclude fire damage - III.G.2 does not allow MOAs in lieu of protection. Contrary to the above, on April 21, 2006, cables of systems necessary to achieve and/or maintain hot standby conditions were not protected from fire damage. Lack of cable protection could result in de-energizing or losing remote control over battery chargers, ventilation equipment and valves important to achieving and/or maintaining hot standby conditions. Instead the plant relied on MOAs to recover from the potential adverse effects. However, in the March 6, 2006, Federal Register Notice (71 FR 11169) that withdrew the proposed rulemaking on manual actions, the NRC stated that, for cases involving feasible manual actions, the licensee would be eligible for enforcement discretion if they initiated corrective actions within six months of the issue date of the notice and completed all corrective actions within 3 years. The licensee has entered this item into their corrective action program as CR 2006100755 and indicated that they plan to require that all manual actions identified in the Safe Shutdown Analysis Report be re-evaluated for compliance with 10 CFR 50 Appendix R, Section III.G.2. The licensee has indicated that they plan to either submit exemption requests to 10 CFR 50, Appendix R, for any unapproved manual actions or implement modifications to eliminate the need for the manual action. The URI was opened to monitor resolution of the MOA issue and determine whether enforcement discretion can be applied. It is identified as URI 05000321, 366/2006006- 001, Local Operator Actions in Lieu of Cable Protection for a Fire Area Subject to the Requirements of III.G.2. |
| Site: | Hatch  |
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| Report | IR 05000321/2006006 Section 4OA5 |
| Date counted | Jun 30, 2006 (2006Q2) |
| Type: | NCV: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | |
| Inspectors (proximate) | L Dymek M Bates R Carrion D Hardage E Morris J Hickey J Montgomeryd Mas Penarandae Lea G Macdonald G Wiseman N Merriweather R Fanner R Rodriguez |
| INPO aspect | |
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Finding - Hatch - IR 05000321/2006006 | |||||||||||||||||
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Finding List (Hatch) @ 2006Q2
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