05000237/FIN-2011004-01
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Finding | |
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| Title | Classification of the Emergency Diesel-Driven Flood Pump to Required Quality Standards |
| Description | At the end of the previous inspection period the inspectors identified an unresolved item (URI 05000237/2011003-01; 05000249/2011003-01) regarding the failure to include adequate acceptance criteria in a surveillance test. On April 8, 2011, the inspectors observed the performance of Work Order (WO) 872864, D2/3 6Y PM Emergency Diesel Pump (Flood Pump) Operation. After the surveillance test was completed, the inspectors reviewed the completed work package and identified that the work instructions did not include acceptance criteria. Task 1 of WO 872864, MM D2/3 6Y PM Emergency Diesel Pump (Flood Pump) Operation, stated that the surveillance was found and left within acceptance criteria. The comments section of Task 2 of WO 872864, Ops Support Flood Emergency Makeup Pump Maintenance, stated there is no specific Acceptance Criteria in Task 01. The licensee generated issue report (IR) 1209642, NRC Identified URI with Flood Acceptance Criteria, to address the inspectors concerns. Calculation DRE99 0035, Capacity and Discharge Head for Portable Isolation Condenser Make Up Pumps to be used during Flood Conditions, Revision 4, determined that the most demanding hydraulic requirement for the flood pump is 350 gpm at 47 psig. Dresdens Updated Final Safety Analysis Report (UFSAR), Section 3.4.1.1, External Flood Protection Measures, requires, in part, that the emergency flood pump be capable of providing at least 175 gpm flow to each unit, should the flood levels exceed 517 feet. 10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires that licensees establish a test program to assure that all testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents. Hence, the inspectors concluded that the test procedure for testing the emergency flood pump should have had acceptance criteria to demonstrate that the flood pump will perform satisfactorily in service. Upon further discussions with the licensee, the inspectors noticed that in early 2007, the flood pump was reclassified as non-safety-related. Based on the definition of safety-related systems, structures and components, as described in Title 10 of the Code of Federal Regulations, Part 50.2, Definitions, and based on the fact that that the flood pump is utilized to mitigate the consequences of an event described in Section 3.4.1.1, External Flood Protection Measures, of the Dresden UFSAR, the inspectors were concerned that the flood pump had been misclassified as non-safety and it should have been classified as a safety-related piece of equipment. The licensee was unable to produce documentation that explained the rationale behind the safety downgrade. However, licensee management personnel stated that the licensing basis definition for safety-related equipment for Dresden only included equipment used to mitigate design basis accidents described in Chapter 15 of the UFSAR. This definition was different than the definition of safety-related in 10 CFR 50.2, which states: Safety-related structures, systems, and components means those structures, systems, and components that are relied upon to remain functional during and following design basis events to assure: (1) The integrity of the reactor coolant pressure boundary; (2) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (3) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to the applicable guideline exposures set forth in 50.34(a)(1) or 100.11 of this chapter, as applicable. The licensee generated IR 1239579, NRC Questions the Safety Classification of Diesel Flood Pump, to address the inspectors concerns. As part of this IR, the licensee generated an action to determine if the safety classification of the flood pump was appropriate based on Dresdens design bases. At the end of this inspection period the licensee was unable to produce any documentation that demonstrated that the NRC had accepted the definition that the term safety-related only referred to equipment used to mitigate UFSAR, Chapter 15 accidents. The licensees closure document for IR 1239579 stated that there was not a clear definition of a design basis event. The licensee concluded that the emergency diesel-driven flood pump should be classified as non-safety-related. However, 10 CFR 50.49(b)(1)(ii), while intended for environmental qualification of electrical equipment, provides a clear definition of design basis events and states, Design basis events are defined as conditions of normal operation, including anticipated operational occurrences, design basis accidents, external events, and natural phenomena for which the plant must be designed to ensure functions (b)(1)(i) (A) through (C) of this section. Those functions in 10 CFR 50.49 are the same as those listed in 10 CFR 50.2. (i) This equipment is that relied upon to remain functional during and following design basis events to ensure-- (A) The integrity of the reactor coolant pressure boundary; (B) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (C) The capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures comparable to the guidelines in 50.34(a)(1), 50.67(b)(2), or 100.11 of this chapter, as applicable. In addition, UFSAR Section 3.2.7, Identification of Safety-Related Components of Systems or Structures, stated that Generic Letter 83-28, Required Actions Based on Generic Implications of Salem ATWS Events, defines safety-related systems and components. That definition is the same as 10 CFR 50.2. UFSAR Section 3.2.7 also stated that subsequent to Generic Letter 83-28 a reclassification of mechanical and electrical systems and components was under taken utilizing the Guideline for safety classification of systems, components, and parts used in Nuclear Power Plant Applications (NCIG-17) NP-6895 Research Project Q101-20 Final Report, February 1991. Flooding was included in the definition of a Design Basis Event in NCIG-17 on page 4-3. Finally, 10 CFR Part 50, Appendix A, Criterion 2Design bases for protection against natural phenomena states, in part: Structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions. Structures, systems, and components important to safety at Dresden are not designed to withstand the effects of a maximum probable flood. Dresden was designed and constructed before the design criteria in 10 CFR Part 50, Appendix A, were required and therefore, both Dresden units were licensed before the requirements to protect against flooding were developed. However, Dresden Unit 2 was reviewed by the NRC as part of the Systematic Evaluation Program (SEP). The purpose of SEP was to determine if an adequate level of safety existed at the plants that were licensed before the 10 CFR Part 50, Appendix A, Design Criteria were developed. Flooding was one of the areas reviewed under SEP. The NRC stated in NUREG-0823, Integrated Plant Safety Assessment, dated February 1983, that the licensees flood emergency plan in its existing form (at the time) was inadequate. One reason was that the plan did not adequately address post-flood conditions such as sources of emergency cooling water. The NRC recommended that the licensee have the capability to install and operate an emergency pump above the probable maximum flood level capable of providing water to the isolation condenser and other cooling needs for the duration of the flood. Since the emergency diesel-driven flood pump described earlier is the only component capable of providing condensate water to the isolation condensers and make up water to the fuel pools on both units during and after a maximum probable flood, the inspectors concluded that the emergency diesel-driven flood pump was necessary to maintain both reactors in a safe shutdown condition and prevent a potential offsite exposure due to a loss of inventory in both unit fuel pools. Therefore, the inspectors concluded that the emergency diesel-driven flood pump was required to be classified as safety-related in order to ensure that the safety function was met. Subsequent to the end of the inspection period, and after the initial exit meeting, on October 28, 2011, the licensee presented the inspectors with substantial additional documentation regarding the safety classification status of the emergency diesel-driven flood pump. The licensee contended that this documentation demonstrated NRC approval of the flood pump classification as other than safety-related. Since the inspectors have not completed their review of this additional documentation, the emergency diesel-driven flood pump safety classification is considered an Unresolved Item (URI 05000237/2011004-01; 05000249/2011004-1, Classification of Emergency Diesel-Driven Flood Pump to Required Quality Standards) pending further inspector review. Reaching an enforcement conclusion on the failure to include adequate acceptance criteria in the emergency flood pump surveillance is dependent on the safety classification of the flood pump. Therefore, URI 05000237/2011003-01; 05000249/2011003-01 remains open pending the above review. |
| Site: | Dresden  |
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| Report | IR 05000237/2011004 Section 1R01 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.01 |
| Inspectors (proximate) | D Jones D Melendez Colon G Roach J Cameron J Corujo Sandin T Goj Draperl Jones J Corujo-Sandin R Orlikowski D Melendez-Colon C Phillips M Ring |
| INPO aspect | |
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Finding - Dresden - IR 05000237/2011004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Dresden) @ 2011Q3
Self-Identified List (Dresden)
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