IR 05000331/1999011
| ML20217F732 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 10/07/1999 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20217F727 | List: |
| References | |
| 50-331-99-11, NUDOCS 9910210052 | |
| Download: ML20217F732 (15) | |
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U. S. NUCLEAR REGULATORY COMMISSION REGIONlli Docket No: 50-331 License No: DPR-49 Report No: 50-331/99011(DRP) Licensee: Alliant, IES Utilities In First Street P. O. Box 351 Cedar Rapids, IA 52406-0351 Facility: Duane Arnold Energy Center Location: Palo, Iowa Dates: August 20 through September 30,1999 Inspectors: P. Prescott, Senior Resident inspector M. Kurth, Resident inspector Approved by: M. N. Leach, Chief Reactor Projects Branch 2 Division of Reactor Projects 9910210052 991007 PDR ADOCK 050C0331 G PDR
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- EXECUTIVE SUMMARY Duane Amold Energy Center NRC Inspection Report 50-331/99011(DRP)
This inspection report included the resident inspectors' evaluations of aspects of licensee i operations, engineering, maintenance, and plant suppor ) Operations
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The inspectors noted good performance by the operations shift personnel during routine . activities and maneuvering of the plant for emergent equipment problems. This included i effective communications and good operator knowledge of equipment status .
(Section 01.1).
l Maintenance
. In general, surveillance tests and maintenance activities were conducted in an acceptable manner. However, the inspectors identified a contractor control issue during the spent fuel pool characterization survey work, and emergent equipment problems I were noted during the "A" standby emergency diesel generator maintenance outage (Section M1.1).
. The inspectors noted that several emergent equipment issues were repetitive, such as !' the hydrogen /oxygcw containment analyzer pump problems, rectifier bank leaks, and the instrument air dryer power trips. The maintenance and engineering staffs continued to work with vendor representatives to determine long term corrective actions (Section M2.1).
f Enaineerina
. The inspectors identified uveral examples of failure by the licensee to amend
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surveillance test procedures to incorporate changes that reflected the improved Technical Speatications ultimate heat sink temperature. Due to data not yet available to , support the licensee's conclusions that the emergency service water temperature limits were acceptable, this was considered an Unresolved item (Section E3.1). ;
. The inspectors noted some minor technical support deficiencies with the licensee's safety evaluation and Technical Requirements Manual Change Revision for removal of the requirement that the residual heat removal service water system heat exchanger was not needed to ensure operability of the containment spray systems (Section E3.2).
Mant Sucoort
. The inspectors observed a contract employee sleeping in a low dose area on the refuel floor. Work was being conducted in the general area where the individual slept and plant employees did not attempt to wake the person (Section R1.1).
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Report Details '
. Summary of Plant Status The licensee operated the plant at 100 percent power at the beginning of this inspection perie On August 27,1999, at 11:07 p.m., operators reduced reactor power to 75 percent for a control rod sequencing exchange. At 4:20 a.m., on August 28, full power operation was resumed. On August 29, a crack 3 inches long was discovered on one of the two "A" cooling tower main condenser circulation water discharge distribution headers. On September 2, further inspection of the cooling tower found broken structural braces undemeath the cracked piping. On September 3, at 4:09 p.m., operators proceeded to reduce reactor power in preparation to remove the "A" cooling tower from service. At 9:34 p.m., the down-power was stopped at 51 percent power and the "A" cooling tower was removed from service. Over the next several days, operators raised reactor power to a peak of approximately 65 percent power. On September 7, at 8:55 p.m., operators commenced a down-power to remove the "A" recirculation motor-generator from service for generator end brush replacement. On September 7, at
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- 11:36 p.m., the down-power was stopped at 42 percent power and the *A" recirculation motor-
. generator set was removed from service and single loop operation was entered. On September 8, at 3:19 a.m., operators retumed the plant to two-loop operation and reactor power was increased. The plant was operated in a cyclical manner corresponding to changes in cooling tower temperature and main condenser bac' pressure. Maximum reactor power was 78 percent. On September 16, the "A" cooling tower .vas partially restwed to service and at 9:03 p.m. operators increased reactor power. On September 17, full power operations were resumed. On September 30, at 9:29 p.m., operators brought the plant to 73 percent power to perform control rod drive scram time testing on a rod that has been running hot due to a potential cooling water flow problem. The control rod drive was tested satisfactorily and declared operabl I. Operations 01 Conduct of Operations 0 Observations of Routine Activities and a Power Reduction and Ascension Insoection Scooe (71707)
The inspectors conducted numerous reviews of operators and operations management during shift activities. These reviews included observations of control room shift turn-overs and operator performance during p' ant evolutions. The inspectors interviewed operations personnel regarding plant status, events, and reviewed daily log The inspectors observed the following significant plant evolutions: o On August 27 and 28,1999, operators reduced power to 75 percent for a control rod sequencing exchang ) i I
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On September 3, operators reduced power to 51 percent to remove the i
"A" cooling tower from service due to structural integrity concem *
On September 7, operators commenced a down-power to 42 percent and entered single loop operation to remove the "A" recirculation motor-generator from service for maintenanc .
. On September 16 and 17, operators retumed the plant to full power following the completion of temporary repairs to the "A" cooling towe On September 30, operators reduced reactor power to 73 percent power to perform scram time testing on control rod drive 14-31, due to concerns that the rod was hot due to potential cooling water flow problems, Observations and Findinos The inspectors observed that operations personnel effectively communicated operational information, maintained accurate records, and were knowledgeable of plant and equipment status. The inspectors observed that operations personnel conducted effective shift tum-overs and properly used procedures. In general, the conduct of operations was appropriately focused on safet On September 3,1999, licensee management decided to reduce reactor power in order to remove the "A" cooling tower from service following an inspection and a subsequent recommendation from an engineer of a cooling tower vendor (see Section M2.1 of this inspection report for details). Operators proceeded with a controlled power reduction to 51 percent. Response by the shift operators was appropriate to a stuck *B" motor-generator set temperature control valve that occurred during the power reductio On September 7, licen:ee management conservatively decided to remove the "A" recirculation motor-generator from service in order to replace the generator end brushes. Operators entered single loop operations. Following brush replacement, operators retumed the plant to two-loop operation. Both evolutions were conducted error-fre Conclusions The inspectors noted good performance by the operations shift personnel during routine activities and maneuvering of the plant for emergent equipment problems. This included effective communications and good operator knowledge of equipment statu Operational Status of Facilities and Equipment O2.1 Gener el Plant Tours and System Walkdowns (71707)
The inspectors followed the guidance of Inspection Procedure 71707 in walking down accessible portions of two systems. The systems chosen, based on maintenance work activities and pmbablistic risk significance, were:
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Residual Heat Removal Service Water System
. "A" Standby Emergency Diesel Generator Equipment operability, material condition, and housekeeping were acceptable in all cases. The inspectors did not identify any substantive concerns as a result of these walkdown II. Maintenance M1 Conduct of Maintenance M1.1 General Comments Insoection Scope (62707 and 61726)
The inspectors observed all or portions of the surveillance test activities and work request activities listed below. The applicable surveillance test or work package documentation was reviewed. Specific tests and work request activities observed are listed below: Maintenance Activities
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Preventive Work Order 1109906: "A" standby diesel generator; Mechanical inspection
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Work Order (WO) A48214: V46-0027 residual heat removal service water (RHRSW) pump IP-22c discharge isolation repair valve disc T-head; Repair vatve body guide ribs and disc guide slots
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Characterization surveys of the non-fuel in the spent fuel pool and cask pool
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Work Order A44683: "A" cooling tower repair work , Surveillance of Activities
. Surveillance Test Procedure (STP) 3.1.4-01, " Scram insertion Time Test,"
Revision 3 l . STP 3.1.7-01, "[ Standby Liquid Control] SBLC Pump Operability," Revision 2
. STP 3.4.1-02, " Single Loop Operation," Revision 1 . STP 3.4.2 02," Jet Pump Operability Baseline Data," Revision 0 i . STP 3.5.1-05, "[High Pressure Coolant Injection) HPCI System Operability Test,"
Revision 2 i
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. Observations and Findinas in general, the work associated with these activities was conducted in a professional and thorough manner. Work was performed with the appropriate radiological control measures in place. Technicians were knowledgeable of their assigned tasks and work document requirements. However, the inspectors identified a contractor control issue during the spent fuel pool characterization survey work (see Section R1.1 for details), and several emergent equipment problems were noted during the "A" standby emergency diesel generator maintenance outage (see Section M2.1 for details). The
"A" standby emergency diesel generator maintenance outage exceeded the licensee's expectations for completing work in half of the Technical Specification (TS) limiting condition for operation time-frame; Conclusions in general, surveillance tests and maintenance activities were conducted in an l acceptable manner. However, the inspectors identified a contractor control issue during the spent fuel pool characterization survey work, and several emergent equipment problems were noted during the "A" standby emergency diesel generator maintenance outag M2 Mainte._ance and Material Condition of Facilities and Equipment M2.1 Plant Material Condition Insoection Scope (62707 and 61726)
Jhe inspectors followed licensee actions concerning emergent work items detailed below to ensure appropriate operability evaluations were performed, TSs were met, repairs were made, and root cause evaluations were performed where appropriat Observations and Findinas On August 29,1999, a crack was discovered in one of the two "A" cooling tower main condenser discharge distribution headers. Further inspection of the cooling tower identified broken structural braces that supported the cracked distribution piping. A cooling tower vendor engineer inspected the cooling tower and concluded that the
"D" cell was in poor condition. A combination of an improper modification to the tower when the 60-inch diameter distribution piping was further extended several years ago, and rotting wood structural braces resulted in the poor condition of the cooling towe The licensee conservatively decided to remove the "A" cooling tower from servic . Temporary repairs were made and, on September 16, the cooling tower was placed back in service. Additional repairs were planned to occur during the upcoming refuel outage that begins October 22. The inspectors noted that prior assessments were performed by a vendor concluding thet the cooling towers were structurally safe and would function adequately until the October 1999 refuel outage, when preventive maintenance activities had been scheduled to begi T . .
On September 17, the main generator rectifier bank number 2 developed a water lea The rectifier was secured and repaired. The licensee in the past had repaired several leaking rectifier bank fittings and concluded that the loose fittings may have been caused by vibration. In this case, the loose fitting may also have been caused by vibratio On September 17, the "A" instrument air dryer power tripped for unknown reasons. This was a repetitive problem that had occurred twice in July 1999. The licensee had attempted to troubleshoot the issue. However, when power was lost, the local indicating alarms lost power. Therefore, the cause of the trips was unknow ~ On September 13 through 18, preventive maintenance for the "A" standby diesel generator (SBDG) was performed. Emergent issues that developed during the maintenance included:
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On September 13, the mechanical overspeed trip mechanbm was tested and tripped below the required range. The trip mechanism was repaired and post-tested satisfactorily, a On September 13, the engine tachometer S13259A, was reading higher than expected during testing. The licensee initiated work card A45188 and used a calibrated portable tachometer to determine engine speed during testing. The licensee was planning corrective maintenance for the engine tachomete On September 16, a small section of oil soaked insulation surrounding the exhaust manifold caught fire during post-maintenance operability testing. The licensee immediately tripped the SBDG and the fire extinguished itself within several minutes. The small fire was of short duration and did not activate the fire suppression system. An operability determination was performed and concluded 1 that surrounding equipment was not damaged. The insulation was removed and replaced on both exhaust manifold ;
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On September 17, the normal air start solenoid SV3261B, developed an air leak during post-maintenance operability testing. The solenoid was replaced and post tested satisfactoril The following emergent equipment issues developed for the hydrogen / oxygen primary j containment analyzers 1C218A and 1C218B: J
* On September 7,1C218B was taken out of service for sample pump replacement due to suspect oxygen readings. The pump was returned to the manufacturer for evaluation. The proper TS limiting condition for operation (LCO) was entered and the pump replacement was completed and post-tested satisfactorily on September 9. The licensee acknowledged that previous sample pump problems had caused a number of entries into TS LCO condition Engineering personnel were working with vendor representatives to determine a ;
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= . On September 16,1C218A was declared inoperable when its reagent test gas cylinder emptied from a possible gas leak. No replacement cylinder was available. Several months prior, the licensee changed the reagent gas mixture in accordance with a vendor recommendation. However, due to a procurement oversight, additional gas cylinders were not ordered. The system engineer initiated Action Request (AR) 16794 to document the reason for the unplanned TS LCO entr * On September 18,1C218B was declared inoperable due to suspect oxygen readings. A 7-day TS LCO was entered for 1C218A and 1C2188 being inoperable. The licensee switched gas cylinders between the' analyzers returning 1C218A to service and the 7-day TS LCO was exited. A 30-day TS LCO condition existed for having 1C2188 inoperabl On September 23, reagent test gas cylinders were received on site and the licensee installed the gas cylinder for 1C2188. However, the licensee then identified a pump / motor coupling failure. Instrument technicians completed repairs and 1C218B was post-tested satisfactorily and the TS LCO was exited on September 2 c. Conclusions The inspectors noted that several emergent equipment issues were repetitive, such as the hydrogen / oxygen containment analyzer pump problems, rectifier bank leaks, and the instrument air dryer power trips. The maintenance and engineering staffs continued to work with vendor representatives to determine long term corrective action Ill. Engineerina E3 Engineering Procedures and Documentation E3.1 Emeroency Service Water System Maximum Temoerature Comoarison to Ultimate Heat Sink Temoerature Limit a. Insoection Scope (37551 and 71707)
The inspectors reviewed the ultimate heat sink (UHS) temperature limit specified in the TS as compared to the emergency service water (ESW) system limiting temperature requirements derived from surveillance test results. The inspectors reviewed the following procedures:
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Duane Amold TSs
- STP 3.0.0-01, " Instrument Checks," Revision 12 - STP NS540002, " Emergency Service Water Operability Test," Revision 3
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Duane Amold Updated Final Safety Analysis Report (UFSAR)
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Action Request 16484, " Emergency Service Water Temperature Versus Ultimate Heat Sink Temperature Limit of 95' [ Fahrenheit] F" b. Observations and Findinas The inspectors noted, during a review of the daily STP 3.0.0-01, that the acceptance criterion for the UHS (river water temperature) was to be less than or equal to 95' This temperature corresponded to the requirements in TS. There were also acceptance criteria for the operations shift crew to verify that the river water temperature was less than the maximum established by the latest performance of the ESW system operability test, STP NS54002. The acceptance criteria required that if the river water temperatur was greater than the temperature limits established by STP NS54002, then operators shall declare the pump (s) inoperable. At the time of the review, ESW loop "A" Tm was 91.8' F and ESW loop "B" Tm was 93.2* F. The inspectors questioned why the ESW temperature was more limiting than the UHS temperature. Also, when the inspectors reviewed the UFSAR flow requirements for components cooled by ESW, the results of STP NS54002 did not align with the UFSAR requirement The inspectors performed a historical review of licensee documentation associated with the change to improved Technical Specifications (ITS). Prior to ITS, the original Duane Amold TS did not specify an actual UHS temperature. However, there was a graph in the original TS of total ESW flow versus river temperature. That graph was based on the sum of individual components cooled by ESW. At some unknown time, additional independent component operability curves were added to the graphs in STP NS54002, and those curve results were added to the UFSAR. However, those curves were not used in STP NS54002 to determine operability. The results of STP NS54002 determined the river water temperature limit. Therefore, an actual river temperature above the total ESW flow curve would have resulted in that ESW loop being declared - inoperabl The licensee adopted a 95* F UHS temperature limit with the conversion to ITS. The ESW versus river water temperature graph was relocated (but not changed) to STP NS54002 to be used as part of the in-service test program. The ESW graph was deleted in the licensee's ITS submittal. In response to NRC questions, the licensee's j engineering staff stated that Generic Letter 89-13 testing verified, based on the data in the UFSAR, that the ESW system would remain operable above the ITS UHS temperature of 95* The inspectors determined that the possibility of exceeding the more limiting ESW temperatures in the remaining summer months were low. Should river temperatures approach the ESW loop limits, the licensee stated it would re-perform STP NS54002 and re-balance the ESW flow rates to components. This should raise the temperature limit for the affected component (s) (i.e., control building chillers). If this was not successful, the licensee would declare that component inoperable and exit the ' ,W sysLm TS LCO. The TS bases supported the licensee's concept of restoring cSW loop operability and declaring the affected component inoperabl )
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Part of the licensee's proposed corrective actions documented in AR 16484 were to perform a safety evaluation to revise the in-service test program to delete or revise the use of the graph that was relocated from the original TS. The safety evaluation would include a review of the documents submitted to the NRC for ITS that pertained to the UHS and ESW specification changes. The safety evaluation would also include a review of the calculations and the basis for the component operability graphs that are in STP NS54002, which match the numbers in the UFSAR. The new safety evaluation would be the basis for revising the in-service test program to only perform required testing, excluding any testing performed for Generic Letter 89-13 purposes. Finally, the daily STP 3.0.0-01 and STP NS54002 would be revised to reflect only the ITS UHS temperature of 95* F. This issue was considered an Unresolved item (50-331/99011-01(DRP)) due to the unavailability of the data to support the licensee's conclusions of the continued operability of the ESW system above the current i ITS temperature of 95* I Conclusions The inspectors identified several examples of failuro by the licensee to amend surveillance test procedures to incorporate changes that reflected the ITS ultimate heat sink temperature. Due to data not yet available to support the licensee's conclusions that the emergency service water temperature limits were acceptable, this was considered an Unresolved ite E3.2 Suporession Pool Sorav TS Bases Chance Insoection Scope (37551 and 71707) The inspectors reviewed a safety evaluation and a Technical Requirements Manual Change Revision (TRMCR) for a TS Bases change. The purpose of the safety evaluation was to justify the non-dependency of the suppression pool spray and drywell spray systems on the RHRSW system. Discussions were held with the licensing and project engineering personnelinvolved in the TS bases changes. The following documents were reviewed:
* Safety Evaluation 99-33 * [ Technical Requirements Manual Change Revision] TRMCR-003 - Technical Specifications and Technical Requirements Manual -
Updated Final Safety Analysis Report
* Action Request 3688, "NRC Bulletin 96-03 (ECCS Suction Strainers) Closeout Work"
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Action Request 14328, "Revied Bases for TS 3.6.2.4 to Delete References to Heat Exchanger"
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GE-NE-T2300752-00-01-R2,"Duane Amold Energy Center Containment ' Analysis" b. Observations and Findinas i Operations management was concemed with the impact of inoperability of the RHRSW system on the suppression pool spray and drywell spray systems. Both the TS and { q Technical Requirements Manual stated that a residual heat removal (RHR) heat I exchanger was required for the operability of the suppression pool spray and drywell -{ spray systems. This implied that the RHRSW system was required for the operability of the suppression pool sprey and drywell spray systems because a heat exchanger ' required flow through the tubes and shell to perform its intended function. The purpose , of the requested safety evaluation was to justify the non-dependency of the suppression
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pool spray and drywell spray systems on the RHRSW syste During a design basis loss of coolant accident, with the drywell pressure and reactor water tevel permissives n et, the flow from one of the low pressure coolant injection pumps could be diverted from the reactor vessel to the containment spray by operator action. The pump flow would be routed through the RHR heat exchanger, where it would be cooled before being discharged to the containment spray headers. Thus, both the containm6nt spray (performed by the spray headers) and suppression pool cooling (performed by the RHRSW heat exchanger) functions were performed. As analyzed in GE-NE-T2300752-00-01-R2, the suppression pool spray and drywell spray systems were capable of performing the design function without the use of the RHRSW heat exchanger because suppression pool temperature was maintained below saturated conditions by the suppression pool cooling during the design basis accident scenario In the safety evaluation, the inspectors noted that initially the issue of not having the ; heat exchanger available to ensure adequate net positive suction head for the pump
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was not addressed. Additionally, the issue of potential degradation of the heat exchanger due to no RHRSW available was not considered. The analysis and safety evaluation did support the ability to maintain containment integrity without containment sprays. The licensee subsequently revised the safety evaluation to correct for the omission The inspectors also noted two issues with the TRMCR-003. The licensee did not omit in the Plant System Bases, Section B3.7.1, the following statement, "The RHRSW system is operated whenever the RHR heat exchangers are required to operate in the shutdown cooling mode or in the suppression pool cooling or spray mode of the RHR system."
Also, a statement in the Containment Systems Bases, Section B3.6.2.4, deleted the statement, "Thus, both suppression pool cooling and suppression pool spray function are performed when the suppression pool spray system is initiated." This statement , was still true in order to consider the suppression pool spray system was still operable and met the analysis. All of the issues discussed above were documented on AR 13487. The licensee was in the process of incorporating the information into the safety evaluation and TRMCR-00 l
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. . Conclusions The inspectors noted some minor technical support deficiencies with the licensee's
' safety evaluation and Technical Requirements Manual Change Revision for removal of the requirement that the residual heat removal service water system heat exchanger was not needed to ensure operability of the containment spray system IV, Plant Support R1 Radiological Protection and Chemistry Controls R1,1 Characterization of Non-fuel items in the Soent Fuel Pool a. Inspection Scope (71750) The inspectors assessed the radiological protection practices that supported the waste J characterization of non-fuel items in the spent fuel pool. The inspectors reviewed procedures Administrative Control Procedure (ACP) 1411.22, " Control of Access to Radiological Areas," Revision 8, and ACF 1411.27, " Rules of Conduct of Work in Radiological Areas," Revision b. Observations and Findiagg On September 8,1999, the inspectors observed radiation protection personnel and contractors perforr,iing characterization surveys of non-fuel items in the spent fuel pool (SFP). The !r. formation was being gathered to confirm what items were located in the SFP, their associated dose rates, and to develop a properly shielded cask to transfer the items offsite for disposa Individuals working in potentially contaminated areas wore the proper protective clothing. The personnel supporting the work on the refuel floor wore the proper dosimetry and took the necessary precautions to minimize doses by standing in low dose areas. As the inspectors observed the work activities, it was noted that a contract i employee was sitting on the refuel floor asleep. The inspectors brought this to the I attention of the refuel floor supervisor and he awoke the individual. The area where the individual slept was a low dose area, approximately 0.3 millirem per hour; therefore, the individual received a minimal dose, it was noted that work activities were being conducted in the general area; however, plant employees did not attempt to wake the individual. Administrative Control Procedure 1411.27 required, in part, that individuals in radiological areas be in a mentally alert and physically sound condition for performing assignmi work. This failure constitutes a violation of minor significance and is not l subject to formal enforcement action. As documented in NRC Inspection l Report 050-331/98004(DRP), a number of human performance problems occurred, including contract employee performance, during the last scheduled refuel outage. The upcoming refuel outage begins in late October 1999. This item was entered in the licensee's corrective action program as AR 1668 r-
. Conclusions The inspectors observed a contract employee sleeping in a low dose area on the refuel floor. Work was being conducted in the general area where the individual slept and plant employees did not attempt to wake the perso V. Manaaement Meetinas X1 Exit Meeting Summary The inspectors presented the inspection results to members of licensee management at the conclusion of the inspection on September 30,1999. The licensee acknowledged the findings presented. The inspectors asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identifie ,
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PARTIAL LIST OF PERSONS CONTACTED Licensee
' D. Curtland, Operations Manager - D. Wilson, Vice President Nuclear G. Van Middlesworth, Plant Manager J. Bjorseth, Maintenance Superintendent
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' K. Peveler, Manager, Regulatory Performance M. McDermott, Manager, Engineering -
R. Hite, Manager, Radiation Protection R. Anderson, Manager, Outage and Support INSPECTION PROCEDURES USED IP 37551: Onsite Engineering IP 61726: Surveillance Observation IP 62707: Maintenance Observation IP 71707: Plant Operations IP 71750: Plant Support ITEMS OPENED, CLOSED, AND DISCUSSED Opened-50-331/99011-01 URI Unavailability of data to support conclusions of continued operability of ESW system Closed None Discussed None 14 ,
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LIST OF ACRONYMS USED ACP ' Administrative Control Procedure ALARA As low as reasonably achievable AR Action Request CFR' Code of Federal Regulations DAEC Duane Arnold Energy Center DRP Division of Reactor Projects ESW Emergency service water F Fahrenheit IP- Inspection procedure ITS Improved Technical Specifications LCO Limiting condition for operation NCV- Non-cited violation NRC Nuclear Regulatory Commission RHR Residual heat removal RHRSW Residual heat removal service water SBDG Standby diesel generator SFP Spent fuel pool STP Surveillance Test Procedure TRMCR Technical Requirements Manual Change Revision TS Technical Specification UFSAR Updated Final Safety Analysis Report UHS Ultimate heat sink URI Unresolved item WO Work Order 15 }}