IR 05000346/1998003

Insp Rept 50-346/98-03 on 980223-26.No Violations Noted. Major Areas Inspected:Engineering

ML20216C394
Person / Time
Site:	Davis Besse
Issue date:	03/10/1998
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20216C387	List: IR 05000346/1998003 ML20216C382
References
50-346-98-03, 50-346-98-3, NUDOCS 9803160006
Download: ML20216C394 (14)

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U.S. NUCLEAR REGULATORY COMMISSION REGION 111 l

l Docket No: 50-346 l License No: NPF-3

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Report No: 50-346/98003(DRS)

Licensee: Toledo Edison Company i

i Facility: Davis-Besse Nuclear Power Station Location: 5503 N. State Route 2 Oak Harbor, OH 43449

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Dates: February 23-26,1998 Inspector: Michael J. Miller, Reactor Engineer i

Approved by: John M. Jacobson, Chief, Lead Engineering Branch ,

Division of Reactor Safety l l

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9903160006 980310 W

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PDR ADOCK 05000346 G PDR tj.-

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EXECUTIVE SUMMARY Davis-Besse Nuclear Power Station NRC Inspection Report 50-346/98003(DRS)

This inspection was to follow up on the items identi'ied in the Davis-Besse Design Inspection (NRC Inspection Report No. 50-346/97-201) conducted from April 14 through June 20,199 The report covers a four-day on-site inspection by one regional inspector. Three unresolved items and five inspection follow up items were closed; three inspection follow up items remain ope Enaineerie

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Timely and appropriate engineering evaluation of the seismic concern, for non-safety pressure gages tied to safety systems, facilitated prompt closure of this ite .

There was a lack of significant progress on environmental qualification of support equipment in the emergency core cooling system room .

Engineering was proactive in reviewing inspection findings at other nuclear sites for applicability to Davis-Besse and in reviewing original licensing review questions and answers to verify appropriate incorporation in the Updated Safety Analysis Repor .

Engineering judgement proved to be correct conceming the structural adequacy of mounting brackets for the borated water storage tank level instrument.

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Report Details This inspection was to follow up on the items identified in the Davis-Besse Design Inspection (NRC Inspection Report No. 50-346/97-201) conducted from April 14 through June 20,199 '

The three unresolved items and eight inspection follow up items identified in the Design Inspection Report are discussed belo lll Enaineerina E8 Miscellaneous Engineering issues (37550)

E (Closed) Insoection Follow un item 50-346/97201-01: calculations were not available to support the high pressure injection (HPI) response time to a steam generator (SG) tube rupture as described in Updated Safety Analysis Report (USAR) Table 15.4.2-2. The licensee attempted to retrieve the calculation from the vendor's archives; however, the calculation could not be found by the vendo in this scenario, the double-ended SG tube rupture flow was within the small break loss of cooling accident (LOCA) spectrum and full injection capacity was always available from at least one HPl train, so the event was similar to a small break LOCA. However, the HPl response time for HPl to begin injecting and the required flow rate were less demanding than for other small break LOCAs. Therefore, the accident remained bounded by the small break analysis. In addition, the licensee committed to validate the values presented in USAR Table 15.4.2-2, " Summary of the Steam Generator Tube Failure Analysis," by December 31,1998. A contractor has been requested to perform the calculation and the licensee was tracking this item in the Toledo Edison Regulatory Management System under A1895 i Based on the bounding analysis and the licensee's commitment to revalidate the USAR table, this item is close E8.2 (Closed) Insoectiorfilw uo item 50-346/97201-02: the team identified that instrument lines for @.; HPl system contained normally opened isolation valves and that pressure gages on the line were not seismically qualified. The isolation valves were ASME Code, Section Ill, Class 2 valves and were the boundary between the Class 2 system piping ard the non safety-related sensing lines and pressure gages. While the remainder of the non safety-related components were designed and supported to ,

seismic class I requirements, the gages could fail during a seismic even I Following the team's identification of the issue, the licensee found a total of 68 gages that were similar. In each case, the gages served no safety function so the concern was that the gages may not maintain the pressure boundary during a seismic even The licensee demonstrated that under the worse case condition, the maximum seismic force to any of the gages in question was 0.60 times the force of gravity (g's). This included consideration of the mounting and location of the gages in the plant. The

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licensee was able to correlate each make and model of gage in question, to specific

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seismic qualification reports. The results for each gage far exceeded the 0.60 g's needed to maintain the pressure boundarv. This item is close E8.3 (Ocen) Insoection Follow uo item 50-346/97201-03: the team questioned the lack of environmental qualification of equipment in the emergency core cooling system (ECCS)

rooms. The equipment included: sump pump motors, sump level switches, associated hand switches, and electrical boxes. These components were required to operate under harsh environmental conditions and their failure could jeopardize operation of associated safety-related equipmen The licensee committed to have the environmental qualification of this equipment I complete by March 6,1998. However, little progress had been made. A work request was originally written to obtain the manufacturer, make, model, and other related data of the installed equipment in the plant. The work request was delayed several times and in Febioary 1998, engineering went into the plant and obtained the information directl The information was easily accessible and only required an operator to open the panels so engineering could obtain the information. Due to the delay in obtaining the data, the licensee planned on extending the commitment dat ;

Based on the original licensee's investigation, there was no operability concern; however, the inspector questioned why a Potential Condition Adverse to Quality Report (PCAQR) written on June 9,1997, took so long just to obtain the initial information needed to start the evaluation process. The lack of progress, reflected the lack of priority and management attention given this issu Since the exit for this report, the inspector was informed that some of the equipment has been qualified. The remainder of the equipment was divided into two parts. The

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licensee planned by April 17,1998, to complete qualification on the equipment that i could be qualified and modify the remaining equipment by November 30,199 This issue will rernain open until the licensee has qualified the equipment or replaced it with qualified equipmen E (Closed)Insoection Follow un item 50-346/97201-04: the team questioned the test methodology used to verify that the battery chargers met the design commitment l described in USAR Section 8.3.2.1.3. The USAR stated that each " charger is capable l

of supplying all steady-state DC loads required under any conditions of operation while recharging the battery to a fully charged condition over a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from a

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discharged condition of 105 volts per battery."

l The team reviewed surveillance test procedure DB-ME-03002," Station Battery Service and Performance Discharge Test," and found it did not meet the above requirement However, DB-ME-03003, ' Station Battery Charger Test," demonstrated that technical specification (TS) surveillance 4.8.2.3.2.c.4 was met. This surveillance required a verification at least once per 18 months that the " battery charger would supply at least 475 amperes at a minimurn of 130 volts for at least eight hours."

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The inspector reviewed Calculation C-EE-002.01-010 "DC Cale-Battery / Charger Size, Short Circuit. Voltage Drop," and determined that the current and voltage parameters of the TS requirement allowed for the steady-state DC loads under any condition while fully recharging the battery, from a discharged condition of 105 volts per battery, in eight hours. The TS surveillance requirement was more conservative than the USAR design commitment and, therefore, did verify the USAR commitmen During this review, the inspector noted some questionable data entries in Surveillances DB-ME-03003 for July 18,23, and 25,1996, on charger numbers DBC1P, DBC1N, and DBC1PN respectively. The data recorded for the start of the surveillance was not greater than 475 amperes but was the initial load to the battery charger as the test equipment ramped up the load. Based on the instructions in the procedure, the operator did follow the instructions but missed the intent of recording the dat The licensee issued PCAOR 98-0248 to address the issue and initiated a procedure change that specified recording the start data after the appropriate parameters were reached. The licensee was able to retrieve two of the three charger test files stored on the test computer's hard drive. Based on the files and the controlled program used to operate the test equipment, the inspector agreed that the TS surve;! lance had been completed satisfactorily. The licensee further stated that the operatoN signature for the acceptance criteria being met was based on the computer data at the end of the surveillance and not on the recorded values on the shee The inspector was concerned that the documentation error had not been caught by the supervisor's review and the system engineer's review. The licensee acknowledged that the error should have been recognized by the reviews and demonstrated a lack of attention to detail. The inspector found no problems for the DB-ME-03003 surveillances i conducted in 1997 (for DBC2P, DBC2N, and DBC2PN). ]

The inspector concluded that the licensee had verified the USAR design commitmen l This item is close I E8.5 (Closed) Insoection Follow uo item 50-346/L U1-05 rectifiers, inverters, and constar,'

voltage transformers were not being tested to demonstrate the specified capabilities or the available margins under abnormal conditions of the 120 volt AC system. Based on a review of NRC surveillance testing requirements and the technical specification, the NRC concluded, as a minimum, that the licensee should verify the following:

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once per 7 days - that the inverters, rather than the constant voltage transformers, are supplying power of proper voltage and frequency to the essential instrumentation distribution panels, l

= periodically test (e.g. during refueling outages) that the reversed-biased diodes, separating the rectifiers from the essential de distribution panels, are capable of conducting current in the forward direction to supply the inverte i~

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._ Weekly surveillance test procedure DB-SC-03041, "Onsite AC Bus Sources Line UP, Available and Isolated (Modes 1,2,3 and 4)," did require verification that the inverter was suppiying the load, that the output voltage was in the acceptable range, and separately verifiad t!'at each trouble light was not lit. The trouble lights irduded a check that the inverter was synchronized with the altemate AC source which requia ad proper inverter outpui dequency. During the refueling outage, the inverter output wave shape and frequency were tested. In addition, each trouble light function was tested. During DB-SC-03114, " Safety Features Actuation System Integrated Time Response Testing,"

the reverse-biased diodes were tested as a result of the test sequenc Based on the above surveillances performing the minimum required checks, this item is close E8.6 (Closed) Unresolved tism 50-346/97201-06: the team identified discrepancies in the USAR that had not been updated in a timely manner. However, the team also recognized that the licensee had initiated a USAR program in August 1993 to review and update the USAR.' A review of that process reveled that the licensee was appropriately resolving the issues identified.

l The licensee had a USAR review process in place with defined scope and schedule. Of l the minor issues identified in this URI, the most significant issue was identified by the

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licensee. The licensee had already submitted a license amendment request (LAR)in April 1997, and was appropriately waiting for the approval before revising the USA Since the team inspection, the LAR was approved, a USAR change notice had been processed, and the modification had been implemented with testing and turnoverin progress. Therefore, this item was not considered a discrepanc I The issue conceming USAR Table 7.5-1 listing the HPI and low pressure injection (LPI)

flow readouts in the main control room as being analog, digital, and computer points when only analog and digital were actually in the control room was minor. The licensee lssued a change request to remove the "D" (for digital) from two locations in the table.

l l The timing sequence listed in USAR Section 15.4.4.2.6.6 was originally added during j initial licensing at the request of the NRC to demonstrate the conservatism used. The analysis and the actual time response tests showed that the actuation would occur l sooner. The calculation referenced in the URI, was for a different scenario and had not been implemented yet. Although the analysis and actual time response testing showed a faster response than the conservative numbers listed in the USAR, the difference did not constitute a discrepancy that required updatin The inspector reviewed the remaining issue concerning a conflict between Section 6.3.1.4 and Section 6.3.5. When the statements were taken in context, they were not contradictory.

I The issues cited in this URI have been resolvd This item is close i

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! E8.7 (Closed) Unresolved item 50-346/97201-0Z: the design basis for valves DH81, DH82, HP31, and HP32 was apparently not correctly translated into procedures and instructions. The concem was that the valves were not being tested for leakage. The licensee identified that these check valves were not being tested as required and documented the problem in PCAOR 97-529 on April 23,1997, l l The licensee was reviewing inspection findings at other sites for applicability to Davis-Besse. The licensee identified that these check valves were not being tested, wrote the PCAOR, and started developing a test procedur Two of the valves, DH81 and DH82, were required to be tested due to the design description found in the recently revised USAR. The licensee had initiated an effort to review original licensing review questions and answers to verify that they had been properly incorporated into the USAR. One item that was identified and added to the USAR in December 1996, was that DH81 and DH82 had a design function to prevent backflow to the borated water storage tank (BWST). While the function of these valves should have been documented in the USAR earlier, the licensee's actions to revisit the original licensing questions and answers was noteworth i This item was licensee identified and corrective actions were prompt and appropriat The licensee issued PCAQR 97-0529 before the full team arrived on site to start the actualinspection. Testing of the valves was completed and the valves passed satisfactorily. The valves were added to the testing program for quarterly testing. The licensee's actions of reviewing the originallicensing questions and answers to ensure appropriate incorporation into the USAR, and the monitoring of inspection findings at other sites to verify the condition didn't exist at Davis-Besse, were proactive. This corrected and non-repetitive violation is being treated as a Non-Cited Violation consistent with Section Vll.B.1 of the NRC Enforcement Poliev (NCV 50-346/98003-01).

E8.8 (Closed) Insoection Follow Lo Item 50-346/97201-08: the team questioned the validity of leakage testing that did not address temperature compensation between the

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temperature the tests were conducted at and the temperature that would be expected during post accident conditions. This issue was related to leak testing of valves DH81, DH82, HP31, and HP32; along with monitoring for external leakage from ECC The licensee's test data for the HP integrated system test showed that the leakage was zero, hence HP-31 and HP-32 had zero leakage and temperature correction would not ;

change the results. DH81 and DH82 were tested as part of two low pressure integrated I tests. Some leakage was identified during these tests but it could not be attributed to a specific valve in the system. The results from both low pressure tests remained well l l

within the acceptance criteria. The licensee stated that temperature compensation for j the leak test would not increase the leak rate and may in fact decrease the leakag '

The inspector concluded that if there was increased leakage due to an increased temperature, the leakage would remain well within the acceptance criteria. This part of the issue close ,

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l The team was also concerned that external leakage from ECCS was not checked at or compensated for the temperatures expected following a design basis accident (DBA).

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The inspector confirmed that checks for leaks were made when the systems were operated at lower nominal temperatures. However, the decay heat removal system actually operated at a higher temperature following a reactor shutdown than would be expected following a DBA. Due to ALARA concems, the licensee chose not to perform the walkdown looking for leaks during that time. The licensee indicated that there was no evidence (such as boron crystals remaining on components) that the system experienced any additional!sakage during the higher temperature operation than was observed at nominal temperatures. TS 6.8.4 requires that the licensee should reduce leakage from those portions of systems outside containment that could contain highly radioactive fluids during a serious transient or accident to as low as practical. The inspector concluded that this TS dealt with attempting to minimize the leakage and testing the system at a higher temperature did not effectively change the results. This issue is close E8.9 (OPEN) Insoection Follow un item 50-346/97201-09: the team noted several inconsistencies in the BWST low-low level trip setpoint value shown in various document Progress had been made on this issue. The licensee performed a new calculation (C-NSA-049.01-004) which verified the minimum BWST level where the transfer for ECCS suction should be initiated by operators. In addition, the Calculation C-lCE-48.01-004 was revised to change the reference to this new calculation. The licensee has extended the commitment date to July 31,1998, for completion of Calculation C-lCE-48.01-004. The extension will allow consideration of other issues not relred to this inspection follow up item before completing the calculatio This item will remain open until Calculation C-ICE-48.01-004 is complete E8.10 (Ocen) Insoection Follow uo item 50-346/97201-10: the team noted inconsistencies in the documentation for the backup safety features actuation system (SFAS)

instrumentation trip setpoint for Level 3 containment high pressure. In addition, the licensee was unable to provide supporting documentation for instrument loop inaccuracie The licensee was in the process of changing methodologies for determining instrument errors which, for this setpoint, would improve the operational margin before the SFAS signal would activate. The licensee had started a new instrument error calculation for this setpoint several years ago using the latest information available from the Instrument Society of America (ISA) standard. It was this calculation that the team reviewed. The inconsistencies identified by the team would be resolved once the calculation was completed and an l_AR was approve The standard (ISA-S67.04, Part I, "Setpoints for Nuclear Safety Related

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Instrumentation") was approved in September 1994. While the licensee was not committed to use this standard for future instrument calculations, the licensee planned

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i tu use the standard as guidance for this issue . The licensee committed to complete the calculation and submit an LAR by June 30,1999. The current setpoint actually resulted in a more conservative backup activation of a SFAS signa This item will remain open until the licensee completes the calculation for instrument loop inaccuracies and submits the LA E8.11 (Closed) Unresolved item 50-346/97201-11: the team was concerned that structural integrity of two level transmitters for the BWST (LT-1525B and LT-1525C) could be degraded due to severely rusted mounting hardware. On September 28,1994, the licensee issued PCAOR 94-0840 which identified corrosion on LT-1525B and LT-1525 The licensee concluded that the condition of the transmitter supports was acceptabl The licensee conducted another inspection on January 13,1997, and concluded that the supports were still capable of meeting operability requirements. However, the team noted that the PCAQR and corresponding evaluations only addressed the transmitters in the BWST pit and did not include the two transmitters in the shed, one of which (LT-1525C) had been severely corrode The PCAOR addressed specific material conditions in the pit. It included the mounting hardware for the transmitters as one of the items of concern. Therefore, it was reasonable that the PCAQR did not include the transmitters in the shed. The material condition in the pit was poor due to rainwater in leakage and the licensee focused attention on correcting the leakage before restoring material conditio Correctiv, actions on this issue were slow. The PCAQR review committee flagged the issue fo A of progress when the PCAOR exceeded 1.5 years. It was appropriate that the comi, tee flagged the issue and prompted re-emphasis on the issue; however, the condition should have been addressed more timely, without the prompting of the PCAQR review committe The licensee has sealed the instrument pit and has restored the material condition. The level transmitter that the team indicated had significant corrosion on the mounting hardware and had not been listed in the PCAOR (LT-1525C) was cleaned up and coated to prevent further corrosion. The structuralintegrity had not been compromised by the corrosion and all the original parts were reused. The repair of LT-1525B did have the mounting hardware replaced but this was to minimize leaving the instrument in a tripped condition while the work was completed. The bolts removed from this transmitter had no reduction in diameter and were capable of performing their functio While the material condition was poor and restoration of material condition was slow, the engineering judgement proved to be accurate in that the hardware condition did not effect the structuralintegrity. This item is close j l

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V. Manaaement Meetings X1 Exit Meeting Summary On February 26,1998, the inspector presented the inspection results to licensee rnanagemen The license acknowledged the findings presente The inspector asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identifie i l

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PARTIAL LIST OF PERSONS CONTACTED Licensee M. Borysiak, Electrical / Controls Engineering Supervisor R. Donnellon, Engineering and Services Director J. Freels, Regulatory Affairs Manager C. Kraemer, Licensing T. Lang, Nuclear Engineering Supervisor D. Lockwood, Compliance Supervisor G. Mcintyre, Mechanical System Supervisor F. Swanger, Design Basis Engineering Manager NHC S. Campbell, Senior Resident inspector K. Zellers, Resident inspector LIST OF INSPECTION PROCEDURES USED IP 37550 Engineering LIST OF ITEMS OPENED 50-0346/98003-01 NCV Failure to test valves DH81, DH82, HP31, and HP32 LIST OF ITEMS CLOSED j l

500346/97210-01 IFl Missing calculation to support response time to a steam generator tube rupture 50-346/97201-02 IFl Ability of non-safety related pressure gages to maintain the pressure boundary during a seismic event 50-346/97201-04 IFl Test methodology used to verify that the battery chargers met the USAR design commitment 50-346/97201-05 lFI Rectifiers, inverters, and constant voltage transformers were tiot tested to demonstrate specified capabilities or available margins 50-346/97201-06 URI USAR discrepancies had not been updated in a timely manner 50-346/97201-07 URI DH81, DH82, HP31, and HP32 were not tested as required i 50-346/97201-08 IFl Temperature compensation was not addressed during leak testing 50-346/97201-11 URI Structural integrity for level transmitters on the BWST could be ,

degraded due to severely rusted mounting hardware l 50-0346/98003-01 NCV Failure to test valves DH81, DH82, HP31, and HP32

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[ LIST OF ITEMS DISCUSSED 50-346/97201-03 IFl Environmental qualification of support equipment in the emergency core cooling system rooms 50-346/97201-09 IFl Several inconsistencies were noted in various documents for the

BWST low-low level trip setpoint 50-346/97201-10 IFl inconsistencies were noted in the documentation for the backup

safety features actuation system instrumentation trip setpoint for

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Level 3 containment high pressure

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LIST OF ACRONYMS USED ALARA As Low As Reasonably Achievable BWST Borated Water Storage Tank DBA Design Basis Accident ECCS Emergency Core Cooling System g's Force of Gravity HPl ' High Pressure injection LAR License Amtsndment Request LOCA Loss Of Cooling Accidents LPl Low Pressure injection NCV Non-Cited Violation PCAOR Potential Condition Adverse to Quality Report SFAS Safety Features Actuation System SG Steam Generator TS Technical Specification USAR Updated Safety Analysis Report

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PARTIAL LIST OF DOCUMENTS REVIEWED i The following is a list of licensee documents reviewed during the inspection, including documents prepared by others for the licensee. Inclueen on this list does not imply that NRC inspectors reviewed the documents in their entirety, but, rather that selected sections or portions of the documents were evaluated as part of the overallinspection effort. Inclusion of a document in this list does nnt imply NRC acceptance of the document, unless specifically stated in the body of the inspection repor Number Revision Subiect l C-EE-002.01-010 16 DC Calc-Battery / Charger Size, Short Circuit, l

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Voltage Drop DB-ME 3003.00 1 Station Battery Charger Surveillance Test Procedure i DB-ME-09202 1 Maintenance of Essential Solid-state Controls l Incorporated Un-interruptible Power Supply DB-PF-04150 0 Augmented ECCS Integrated Leakage Test I

DB-SC-03041 2 On- Site AC Bus Sources Lined Up, Available, and Isolated (Modes 1,2,3, and 4) Surveillance l DB-SC-03114 1 SFAS Integrated Time Response Test E-1 31 AC Electrical system One Line Diagram E-7 29 250/125V DC and Instrument AC One line Diagram

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E-56B 8 Radioactive Waste System ECCS Sump Pumps Wiring Diagram M-033A 22 High Pressure injection F'&lD M-033B 29 Decay Heat Train P&lD i M-034 51 Emergency core Cooling system Containment

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Spray & Core Flooding Systems P&lD l MWO 1-97-0408-00 N/A Maintenance Work Order for BWST Level l Transmitter Mounting Bracket Repair NG-NS-00802 0 Commitment Management Procedure PCAOR Date Issued Subiect 94-0840 9/28/94 Material Condition issues identified in the BWST Pit 97-0529 4/23/97 Identified DH81, DH82, HP31, and HP32 were not being tested for specific design function /9/97 Questioned environmental qualification of certain

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equipment in the ECCS room 98-0248 2/13/98 Identified data recording errors in battery charger tests performed in 1996 i 98-0291 2/24/98 Identified missing clamps on 3/8 inch instrument lines that l were seismically supported

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