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| Site | Quarter | Title | Description | |
|---|---|---|---|---|
| 05000416/FIN-2012003-06 | Grand Gulf | 2012Q2 | Failure to Follow Procedure Results in Loss of Decay Heat Removal to the Spent Fuel Pool | The inspectors reviewed a self-revealing non-cited violation of Technical Specifications 5.4.1(a), involving a loss of decay heat removal in the spent fuel pool due to station personnel failing to correctly follow operation of pool gate seal air supply procedure. On April 17, 2012, Grand Gulf Nuclear Station was preparing to drain the reactor cavity to reinstall the vessel head after the completion of refueling activities. In preparation, the upper containment pool to the reactor cavity gate was installed by General Electric-Hitachi technicians with Entergy oversight. Technicians were directed by procedure to verify that all supply isolation toggle valves to the gate seals were open and secured in place. However, technicians failed to complete this action correctly and the control room was informed that all prerequisites were completed and began the cavity drain down. The control room immediately noticed the fuel pool drain tank level was decreasing and attempted to makeup to the tank via the normal makeup valve. When the fuel pool drain tank level reached 17 percent full, both fuel pool cooling and cleanup pumps tripped as expected, resulting in loss of decay heat removal to the spent fuel pool. The main control room entered the off-normal event procedure for inadequate decay heat removal, and they secured the drain down evolution. Approximately 47 minutes later, spent fuel pool cooling was re-established. During this event, the spent fuel pool temperature did not exceed the limits required by Technical Requirements Manual Section 6.7.4 (140F). Short term corrective actions included restoring decay heat removal to the spent fuel pool and conducting a human performance review of the event. The licensee entered this issue into the corrective action program as Condition Report CR-GGN-2012-05756. The finding is more than minor because it is associated with the human performance attribute of the Barrier Integrity Cornerstone and adversely affects the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Using Inspection Manual Chapter 0609.04, Phase 1 - Initial Screening and Characterization of Findings, the inspectors determined that the finding was of very low safety significance (Green) because the finding only represented a loss of spent fuel pool cooling that would not preclude restoration of cooling to the spent fuel pool prior to pool boiling. This finding has a cross-cutting aspect in the area of human performance associated with the work practices component because licensee personnel failed to use adequate self- and peer-checking techniques to ensure gate seals were properly inflated prior to cavity drain down. |
| 05000440/FIN-2011002-01 | Perry | 2011Q1 | Failure to Establish Radiological Conditions in a Locked HRA (i.e., the fuel pool cooling and cleanup (FPCC) heat exchanger room) Prior to Allowing Personnel Access | A finding of very low safety significance and an associated NCV of Technical Specifications (TS) 5.7.2 was self-revealed following the licensees failure to adequately identify the radiological conditions in the fuel pool cooling and cleanup (FPCC) heat exchanger room prior to a pre-job brief for work in the room and prior to workers entering the room. Specifically, on November 19, 2010, operators involved in tag-out activities for a valve encountered elevated dose rates when they entered an un-surveyed area on the back side of the FPCC heat exchanger. At the time the FPCC room was controlled as a locked high radiation area (HRA). While entering the area one of the operators received an electronic dosimeter (ED) dose rate alarm of 1500 mRem/hr. Follow-up surveys determined that the highest dose rate in the area entered was 2000 mrem/hr. As part of the licensees corrective actions, lessons learned were shared with the radiation protection (RP) staff to address survey and briefing inadequacies. Additional performance management actions were implemented by the station. The inspectors determined that the licensees failure to adequately identify the radiological conditions in the room prior to workers entering the work area was a performance deficiency. The inspectors determined that the finding was more than minor because the inspectors identified Example 6(h) of IMC 0612, Appendix E, as similar to the finding; the workers were not made aware of the radiological conditions before entry into the area on the back side of the FPCC heat exchanger. Additionally, the finding impacted the program and process attribute of the Occupational Radiation Safety Cornerstone by adversely affecting the cornerstone objective of ensuring adequate protection of worker health and safety from exposure to radiation in that workers entry into areas, without knowledge of the radiological conditions, placed them at increased risk for unnecessary radiation exposure. The finding was determined to be of very low safety significance because the performance deficiency was not an as-low-as-reasonably-achievable (ALARA) planning issue, there was no overexposure, nor substantial potential for an overexposure, and the licensees ability to assess dose was not compromised. The inspectors determined that the cause of this incident involved a cross-cutting component in the human performance area of work practices in that the work crew proceeded in the face of uncertainty when unexpected circumstances were encountered in the FPCC heat exchanger room. |
| 05000440/FIN-2010003-01 | Perry | 2010Q2 | Failure to Adequately Establish the Radiological Conditions In A Locked High Radiation Area to Allow Workers to Be Properly Briefed Prior to Entry | A finding of very low safety significance and an associated NCV of Technical Specification 5.7.1 was self-revealed following worker entry into the fuel pool cooling and cleanup (FPCC) heat exchanger room. At the time, the FPCC heat exchanger room was being controlled as a locked high radiation area (HRA). The licensee failed to adequately determine radiological dose rates in the room to ensure workers were briefed accurately on the radiological conditions prior to entry. On March 12, 2010, workers involved in tag-out activities in the room encountered greater than expected dose rates. After completion of the tag-out activity, the licensee identified that the electronic dosimeter (ED) worn by one of the workers had a dose rate of 550 mrem/hour and had alarmed. The workers were briefed to expect dose rates no greater than 150 mrem/hour based on the radiation survey used to support the briefing. The radiological information conveyed to the workers through a briefing by the radiation protection (RP) staff was inadequate because it was based on an incomplete survey. As part of the licensees corrective actions, lessons learned were shared with the RP staff to address survey adequacy and for enhanced communications with workers during pre-job briefings. The inspectors identified Example 6(h) of IMC 0612, Appendix E, as similar to the performance issue. The workers were not made aware of the radiological conditions before entry into the room. Therefore, as provided in Example 6(h), the inspectors determined that the performance deficiency was more than minor. Additionally, the performance deficiency impacted the program and process attribute of the Occupational Radiation Safety Cornerstone and adversely affected the cornerstone objective of ensuring adequate protection of worker health and safety from exposure to radiation, in that, worker entry into areas without knowledge of the radiological conditions placed them at increased risk for unnecessary radiation exposure. The finding was determined to be of very low safety significance because the problem was not an as-low-asreasonably- achievable (ALARA) planning issue, there was no overexposure, nor substantial potential for an overexposure, and the licensees ability to assess dose was not compromised. The inspectors determined that the cause of this issue involved the cross-cutting component of work control in the human performance cross-cutting area (H.3.(a)), in that work activities were not adequately planned by incorporating job site radiological conditions. Specifically, the pre-job briefing did not utilize complete and accurate survey maps for the areas being entered into by the workers assigned to conduct tasks in the FPCC heat exchanger room. |
| 05000416/FIN-2010003-02 | Grand Gulf | 2010Q2 | Failure to Follow Procedure Results in Loss of Decay Heat Removal to the Spent Fuel Pool | The inspectors reviewed a self-revealing noncited violation of Technical Specifications 5.4.1(a), involving a loss of decay heat removal in the spent fuel pool due to station operators failing to follow the fuel pool cooling and cleanup system operating instruction. The licensee entered this issue into the corrective action program as Condition Report CR-GGN-2010-02172 This finding is more than minor because it is associated with the human performance attribute of the Barrier Integrity Cornerstone and adversely affects the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Using the Manual Chapter 0609, Significance Determination Process, Attachment 0609.04, Phase 1 Initial Screening and Characterization of Findings, the inspectors determined that the finding has a very low safety significance because it only represented a loss of spent fuel pool cooling that would not preclude restoration of cooling to the spent fuel pool prior to pool boiling. The cause of this finding has a crosscutting aspect in the area of human performance associated with work practices, because licensee personnel failed to use adequate self- and peer-checking techniques to remove the filter/demineralizer from service. |
| 05000237/FIN-2006010-05 | Dresden | 2006Q3 | DOA 1900-01, step D.1.c. Can Not Be Performed Under a Loss of AC Power Coincident with Loss of Coolant Accident (LOCA) Conditions | The inspectors identified an unresolved item regarding the performance of DOA 1900-01, Loss of Fuel Pool Cooling, Revision 14. DOA 1900-01, step D.1.c. can not be performed under a loss of AC power coincident with a loss of coolant accident (LOCA) conditions. On January 18, 2006, during testing of the 2A fuel pool cooling pump, per DOA 1900-01, heat exchanger tube side relief valves 2-1999-279 (A relief valve) and 2-1999-280 (B relief valve) lifted. On January 20, 2006, during testing of the 2B fuel pool cooling pump, per DOA 1900-01, both A and B heat exchanger tube side relief valves (2-1999-279 and 2-1999-280) lifted. The 2A fuel pool cooling pump was tested again on January 20, and both A and B relief valves lifted. Following each of the incidents, DOP 1900-01, Fuel Pool Cooling and Cleanup System Startup, was utilized to reseat the relief valves and return the system to a stable condition. The licensee concluded that after a fuel pool cooling pump trip, the pump can not be re-started without operator manual actions in the reactor building. On January 20, 2006, the licensee determined that DOA 1900-01, step D.1.c. can not be performed under a loss of AC power coincident with loss of coolant accident (LOCA) conditions. Step D.1.c. provides guidance on how to start a fuel pool cooling pump in case access to the reactor building is not possible. This condition affects Unit 2 and likely affects Unit 3. These events were documented in IR 444332. The inspectors challenged the licensee as to whether the condition of Unit 2 (and potentially Unit 3) fuel pool cooling system should be an operator workaround or challenge. The licensee initiated IR 528541 to address the inspectors concern. Also, the inspectors inquired as to whether any compensatory actions were in place and if there was an alternate success path to accomplish the re-start of the fuel pool cooling pumps under a loss of AC power coincident with loss of coolant accident (LOCA) conditions. The compensatory action in place directed operations personnel to take actions to ensure DOA 1900-01, step D.1.c. is not used on either unit until a solution to the problem is implemented. At the end of the inspection period, the licensee was still evaluating if there is an alternate success path to accomplish the re-start of the fuel pool cooling pumps. The inspectors considered this issue to be an unresolved item pending evaluation efforts. |