IR 05000289/2008010
| ML090690605 | |
| Person / Time | |
|---|---|
| Site: | Three Mile Island  |
| Issue date: | 03/10/2009 |
| From: | Conte R Engineering Region 1 Branch 1 |
| To: | Pardee C Exelon Generation Co |
| References | |
| IR-08-010 | |
| Download: ML090690605 (32) | |
Text
rch 10, 2009
SUBJECT:
THREE MILE ISLAND NUCLEAR STATION UNIT 1 - NRC LICENSE RENEWAL INSPECTION REPORT 05000289/2008010
Dear Mr. Pardee:
On December 12, 2008, the NRC completed the onsite portion of the inspection of your application for license renewal of your Three Mile Island Nuclear Station Unit 1. The enclosed report documents the results of the inspection, which were discussed on February 5, 2009 with members of your staff in an exit meeting open for public observation at the Sheraton Harrisburg Hershey Hotel, located at 4650 Lindle Road, Harrisburg, PA.
The purpose of this inspection was to examine the plant activities and documents that supported the application for a renewed license of Three Mile Island Nuclear Station Unit 1.
The inspection reviewed the screening and scoping of non-safety related systems, structures, and components, as required in 10 CFR 54.4(a)(2), and determined if the proposed aging management programs are capable of reasonably managing the effects of aging. These NRC inspection activities constitute one of several inputs into the NRC review process for license renewal applications.
The inspection team concluded screening and scoping of non-safety related systems, structures, and components, was implemented as required in 10 CFR 54.4(a)(2), and the aging management portion of the license renewal activities were conducted as described in the License Renewal Application. The inspection results supported a conclusion that the proposed activities will reasonably manage the effects of aging in the systems, structures, and components identified in your application. The inspection concluded the documentation supporting the application was in an auditable and retrievable form.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Website at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Richard Conte, Chief Engineering Branch 1 Division of Reactor Safety Docket No. 50-289 License No. DPR-16
Enclosure:
Inspection Report 05000289/2008010
REGION I==
Docket No: 50-289 License No: DPR-16 Report No: 05000289/2008010 Licensee: Exelon Generation Group, LLC Facility: Three Mile Island Nuclear Station Unit 1 Location: Harrisburg, Pennsylvania Dates: November 17 - 21, and December 8 - 12, 2008 Inspectors: M. Modes, Team Leader, Division of Reactor Safety (DRS)
G. Meyer, Sr. Reactor Inspector, DRS T. Bilik, Sr. Reactor Inspector, DRS (Region III)
S. Chaudhary, Reactor Inspector, DRS J. Tifft, Reactor Inspector, DRS Approved By: Richard Conte, Chief Engineering Branch 1 Division of Reactor Safety Enclosure
SUMMARY OF FINDINGS
IR 05000289/20009010; 11/17 - 21 and 12/8 - 12, 2008 Three Mile Island Nuclear Station Unit 1;
Inspection of the Scoping of Non-Safety Systems and the Proposed Aging Management Procedures for the Exelon Generation Group, LLCs Application for Renewed License for Three Mile Island Unit 1.
This inspection of license renewal activities was performed by five regional office engineering inspectors. The inspection was conducted in accordance with NRC Manual Chapter 2516 and NRC Inspection Procedure 71002. This inspection did not identify any findings as defined in NRC Manual Chapter 0612. The inspection team concluded screening and scoping of non-safety related systems, structures, and components, were implemented as required in 10 CFR 54.4(a)(2), and the aging management portions of the license renewal activities were conducted as described in the License Renewal Application. The inspection results supported a conclusion that the proposed activities will reasonably manage the effects of aging in the systems, structures, and components identified in your application. The inspection concluded the documentation supporting the application was in an auditable and retrievable form.
ii
REPORT DETAILS
4OA2 Other - License Renewal
a. Inspection Scope
This inspection was conducted by NRC Region I based inspectors in order to evaluate the thoroughness and accuracy of the screening and scoping of non-safety related systems, structures, and components, as required in 10 CFR 54.4(a)(2) and to evaluate whether aging management programs will be capable of managing the identified aging effect in a reasonable manner.
The inspection team selected a number of systems for review, using the NRC accepted guidance; in order to determine if the methodology applied by the applicant appropriately captured the non-safety systems affecting the safety functions of a system, component, or structure within the scope of license renewal.
The inspection team selected a sample of aging management programs to verify the adequacy of the applicants documentation and implementation activities. The selected aging management programs were reviewed to determine whether the proposed aging management implementing process would adequately manage the effects of aging on the system.
The inspectors reviewed supporting documentation and interviewed applicant personnel to confirm the accuracy of the license renewal application conclusions. For a sample of plant systems and structures, inspectors performed visual examinations of accessible portions of the systems to observe aging effects.
a.1. Scoping of Non Safety-Related Systems, Structures, and Components For scoping, the inspectors reviewed program guidance procedures and summaries of scoping results for Three Mile Island, Unit 1 to assess the thoroughness and accuracy of the methods used to bring systems, structures, and components within the scope of license renewal into the application, including non-safety-related systems, structures, and components, as required in 10 CFR 54.4 (a)(2). The inspectors determined that the procedures were consistent with the NRC accepted guidance in Sections 3, 4, and 5 of Appendix F to Nuclear Energy Institute (NEI) 95-10, Rev. 6, "Industry Guideline for Implementing the Requirements of 10 CFR Part 54," (Section 3: non-safety-related systems, structures, and components within scope of the current licensing basis; Section 4: non-safety-related systems, structures, and components directly connected to safety-related systems, structures, and components; and Section 5: non-safety-related systems, structures, and components not directly connected to safety-related systems, structures, and components).
The inspectors reviewed the set of license renewal drawings submitted with the Three Mile Island, Unit 1 License Renewal Application, which was color-coded to indicate systems and components in scope for license renewal. The inspectors interviewed personnel, reviewed license renewal program documents, and independently inspected numerous areas within Three Mile Island, Unit 1, to confirm that appropriate non-safety-related systems, structures, and components had been included within the license renewal scope; that systems, structures, and components excluded from the license renewal scope had an acceptable basis; and that the boundary for determining license renewal scope within the systems, including seismic supports and anchors, was appropriate.
The Three Mile Island, Unit 1 in-plant areas reviewed included the following:
- Turbine Building
- Intermediate Building
- Control Building
- Intake Screen and Pump House
- Condensate Storage Tank (CST) A
- Diesel Generator Building
- Service Building
- Auxiliary Building - Heat Exchanger Vaults
- Station Blackout (SBO) Diesel Generator Building During the walk-down of the river water system within the Intake Screen and Pump House for structural interaction purposes, the inspectors noted that a portion of the system was not represented on the license renewal drawing consistent with the system in-place. The license renewal drawing was based on the plant piping and instrument drawing. The error was not consequential for operational or license renewal purposes.
The applicant initiated AR 00779708 to address the drawing error.
For systems, structures, and components selected regarding spatial interaction (failure of non-safety-related components adversely affecting adjacent safety-related components),the inspectors determined the in-plant configuration was accurately and acceptably categorized within the license renewal program documents. The inspectors determined the personnel involved in the process were knowledgeable and appropriately trained.
While most of the systems and components within the Turbine Building were included within license renewal scope, the applicant excluded a portion of the lower level of the Turbine Building and the contained equipment from license renewal. The inspectors confirmed the appropriateness of this scoping based on reviews, and in-field inspection and walk-downs.
For systems, structures, and components selected regarding structural interaction (seismic design of safety-related components dependent upon non-safety-related components), the inspectors determined that structural boundaries had been accurately determined and categorized within the license renewal program documents. The inspectors determined that the applicant had reviewed applicable isometric drawings to determine the seismic design boundaries and had correctly included the applicable components in the license renewal application, based on the inspectors independent review of a sample of the isometric drawings and the seismic boundary determinations.
In summary, the inspectors concluded that the applicant had implemented an acceptable method of scoping of non-safety-related systems, structures, and components and that this method resulted in accurate scoping determinations
.
a.2 Operational Experience Review NEI 95-10, Revision 6, June 2005 Industry Guideline for Implementing the Requirements of 10 CFR Part 54 - The License Rule suggests a plant specific operating experience review should assess the operating and maintenance history. A review of the prior five to ten years of operating and maintenance history should suffice. The results of the review should confirm consistency with the documented industry operating experience.
Differences with previously documented industry experience such as new aging affects or lack of aging effects allow consideration of plant specific aging management requirements.
Exelon Generation Group, LLC does not perform a plant specific assessment of operating and maintenance history for a minimum period of 5 years for the mechanical systems.
Instead Exelon Generation Group, LLC substitutes, for some part of the 5 years, the information contained in EPRI Non-Class 1 Mechanical Implementation Guideline and Mechanical Tools, Revision 4, January 2006. The application review was frozen, by Exelon Generation Group, LLC, on November 30, 2006 and the period of time a handbook is given credit for is based on the year the handbook was last issued. The end date for which the book is given credit is backed up to January of the year the handbook was in final preparation. At Three Mile Island Unit 1 the handbook was applied up until January of 2005, after which a plant specific review was performed.
Exelon Generation Group, LLC gives this handbook credit, at the plant, for assessing the operating and maintenance of the plant from November 30, 2001 to January 2005.
Exelon Generation Group, LLC then implemented a specific review of the plant operating experience from January 2005 until November 30, 2006. The rationale for this approach is the handbook contains all the aging affects that occurred at Three Mile Island Unit 1 prior to the date the book was issued. Because the information contained in the book is based, in part, on a search of the Epix industry database, for all aging affects for Babcock
& Wilcox reactors in the country, including Three Mile Island, it includes the relevant information from Three Mile Island, for the period it is applied to, as well as the relevant information from all the other plants of similar design in this country (Oconee, Davis Bessie, Crystal River, etc).
The inspector reviewed the relevant Exelon Generation Group, LLC procedures and the EPRI handbook. The EPRI handbook does consider many sources of information for determining aging affects, and does it in a very orderly fashion. The handbook also includes a thorough discussion and consideration of NRC generic communications. EPRI benchmarked the handbook against NUREG 1800 aging affects.
The inspector reviewed the site specific operational experience recorded in selected aging management review basis documents and compared these against the aging affects identified in the handbook. The aging management review operational experience review was thorough and compared favorably with the types of aging affects described in the handbook. The inspector independently searched the corrective actions system for a year when Amergen gave the handbook credit for the specific plant review of operational experience, for a randomly chosen raw water system (Nuclear Services River Water System 531, 2004). No additional aging affects or related operational experience was noted during this search.
The approach taken by Exelon Generation Group, LLC, although no a direct plant specific operating experience review as described in NEI 95-10 it is indirectly a comprehensive review of the aging affects that might be applicable and does take into account more then just the local experience recorded in the Three Mile Island corrective actions program history. The inspectors concluded there reasonable assurance the operational experience review was adequate.
a.3. Programs Selective Leaching Inspection Program The Selective Leaching Inspection Program is a new, one-time program, which is credited with managing the aging of components made of gray cast iron and copper alloys with greater than 15% zinc, exposed to raw water, treated water, and soil environments, which may lead to selective leaching of material constituents, e.g.,
graphitization and dezincification. The program will include a one-time visual inspection and hardness measurement test of selected components that may be susceptible to selective leaching to determine whether loss of material due to selective leaching is occurring, and whether the leaching process will affect the ability of the components to perform their intended function during the period of extended operation.
The inspectors reviewed the program description, program implementing procedure, sampling plan basis document, discussed the planned activities with the responsible staff, and reviewed a sample of corrective action program documents for applicable components, based on an inspector-initiated search of the condition report data base.
The inspectors noted that for some material and environment combinations, the sampling plan specified a single sample. This appeared to be a minimal sample to the inspectors.
The applicant stated that the sampling plan would be revised to have a minimum of three samples for combinations involving the more severe environments, i.e., raw water and soil. The inspectors determined that this sampling was more appropriate and representative.
In addition, the inspectors reviewed corrective actions involving replacements of main steam system caps due to an incorrect material application. The inspectors noted that the replaced caps could provide valid selective leaching data. The applicant stated that these opportunities would potentially be used.
For the Selective Leaching Program, based on a review of site-specific operating experience, the inspectors determined that there were no aging effects at Three Mile Island, Unit 1 outside the bounds of industry operating experience. In program-level documents the applicant provided adequate guidance to ensure aging effects are appropriately identified and addressed.
One-Time Inspection Program The One-Time Inspection Program is a new, one-time program that will be implemented prior to the period of extended operation. The program will verify the effectiveness of other aging management programs, including Water Chemistry, Fuel Oil Chemistry, and Lubricating Oil Analysis Programs, by reviewing various aging effects for impact. Where corrosion resistant materials and/or non-corrosive environments exist, the One-Time Inspection Program is intended to verify that an aging management program is not needed during the period of extended operation by confirming that aging effects are not occurring or are occurring in a manner that does not affect the safety function of systems, structures, and components. Non-destructive examinations will be performed by qualified personnel using procedures and processes consistent with the approved plant procedures and appropriate industry standards.
The inspectors reviewed the program description, program implementing procedures, sampling basis document, discussed the planned activities with the responsible staff, and reviewed a sample of corrective action program documents, including inspector-initiated data searches for applicable material and environment combinations in the emergency feed and fuel oil systems.
For the One-Time Inspection Program, based on a review of site-specific operating experience, the inspectors determined that there were no aging effects at Three Mile Island, Unit 1 outside the bounds of industry operating experience. In program-level documents the applicant provided adequate guidance to ensure aging effects are appropriately identified and addressed.
Fuel Oil Chemistry Program The Fuel Oil Chemistry Program is an existing program, which is credited with managing the effects of aging for loss of material (corrosion) and fouling in fuel oil systems. The aging effects are managed by a combination of periodic chemistry sampling and analysis, and periodic fuel oil tank cleaning and inspection.
The inspectors reviewed the existing fuel oil monitoring program, associated procedures and results for sampling and tank cleaning, and recent fuel oil analysis results to evaluate the effectiveness of the existing program. The inspectors reviewed tank inspection records to verify the results were within the acceptable range. In addition, the inspectors interviewed engineering personnel, and performed field walk-down inspections of the accessible portions of the fuel oil systems for emergency diesel generators, station blackout diesel generator, and river water diesel fire pump, and the diesel fuel oil storage tank to independently assess the material condition of the fuel oil systems and identify inconsistencies between the as-built plant configuration, and the aging management evaluations and programs. The inspectors also reviewed a sample of corrective action program documents related to fuel oil, including an inspector-initiated search of 2005 and 2006 fuel oil system condition reports.
For the Fuel Oil Chemistry Program, the inspectors concluded the applicant had performed adequate evaluations, as well as industry experience and historical reviews, to determine aging effects. The applicant provided adequate guidance to ensure the aging effects will be appropriately identified and addressed.
Buried Piping and Tanks Inspection Program The Buried Piping and Tanks Inspection Program is an existing program, which is credited with managing the effects of external corrosion on the pressure-retaining capability of buried carbon steel, concrete-coated carbon steel, cast iron, and stainless steel piping components and tanks in a soil environment. The aging effects will be managed by preventive measures (i.e., coatings and wrappings) to mitigate corrosion, in accordance with standard industry practice for maintaining external coatings and wrappings and by visual inspections during planned excavations. The program specified performing at least one inspection of each material type within the 10 year period prior to the period of extended operation, either during an excavation for other purposes (i.e.,
opportunistic) or during an excavation planned for this inspection. An additional inspection will also be performed during the first 10 years of extended operation. The program will provide inspection and acceptance criteria, and will require evaluation of the inspection results. Inspections will be performed in accordance with approved station procedures.
The inspectors reviewed the program basis document and program implementing procedures. The inspectors also reviewed a sample of corrective action program documents related to buried piping, including inspection records for nuclear river water piping in December 2005, which had been replaced because of a microbiologically induced corrosion leak, and an apparent cause evaluations for condensate storage tank piping, and microbiologically induced corrosion and buried piping. The inspectors also interviewed selected system and component engineers responsible for the associated program elements and buried components. The inspectors performed field walk-downs to independently assess the material condition of the visible portion of a short section of cast iron fire header piping, which was exposed for unrelated valve work.
For the Buried Piping and Tanks Inspection Program, the inspectors concluded the applicant had performed adequate evaluations, as well as industry experience and historical reviews, to determine aging effects. The applicant provided adequate guidance to ensure the aging effects will be appropriately identified and addressed.
Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Aging Management Program The Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements aging management program is a new program credited with managing the aging effects from insulation degradation due to adverse environmental conditions in cables and connections in the Three Mile Island Nuclear Station - Unit 1.
The aging effects are managed by a sampling visual inspection of cables and connections in adverse localized environments.
This new program will perform periodic visual inspections of cables and connections in adverse localized equipment environments caused by heat, radiation, or moisture which can accelerate aging of electrical cables. A representative sample of accessible electrical cables and connections installed in adverse localized environments and ambient conditions in excess of 60-year service-limiting environments will be visually inspected for jacket surface anomalies that indicate insulation or connection degradation.
The inspectors reviewed draft procedures, conducted walk-downs, and had discussions with plant personnel to assess the proposed program and assure it will be capable of managing aging effects. The inspectors reviewed the scope of the program, which will not distinguish between EQ and non-EQ cables within each area inspected and determined that this conservatively increased the scope of cables inspected. The inspectors concluded that, if effectively implemented as described in the program description documents, the aging effects in accessible cables and connections would be adequately managed.
The inspectors concluded the applicant had conducted adequate evaluations as well as industry experience and historical reviews to determine aging effects managed by an aging management program. The applicant provided adequate guidance to ensure aging effects are appropriately managed.
Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Used in Instrumentation Circuits Aging Management Program The Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Used in Instrumentation Circuits aging management program is an existing program modified for the purpose of aging management credited with managing the aging effects due to reduced insulation resistance in nuclear instrumentation and radiation monitoring instrumentation cables and connections in the Three Mile Island Nuclear Station - Unit 1. The aging effects are managed by performance of existing calibration tests for instrumentation containing the in scope radiation monitoring circuits in the Radiation Monitoring System and by the addition of cable testing of the in scope nuclear instrumentation circuits in the Nuclear Instrumentation and lncore Monitoring System.
This program credits calibration testing for in scope circuits of the Radiation Monitoring System. These calibrations are performed with the circuits intact. Therefore, a test that meets its acceptance criteria indicates that no cable or connection degradation significant enough to prevent the circuit from performing its intended function has occurred. Existing system performance monitoring will be used to detect trends indicating potential cable aging degradation.
The existing program is enhanced for the purpose of aging management with the addition of cable testing. For the in scope nuclear instrumentation in the Nuclear Instrumentation and lncore Monitoring System, the cables and connections will be tested for reduced insulation resistance using current/voltage (IN) or Time Domain Reflectometry (TDR)testing. This testing will be initially performed prior to the period of extended operation and the test frequency will be once every 10 years.
The inspectors reviewed draft procedural guidance for cable testing using acceptable testing methods. The inspectors interviewed relevant applicant personnel regarding how the proposed program will identify age related deficiencies. The inspectors reviewed existing surveillance and calibration procedures and results. The inspectors concluded that, if effectively implemented as described in the program description documents, the aging effects in accessible cables and connections used in instrumentation circuits would be adequately managed.
The inspectors concluded the applicant had conducted adequate evaluations as well as industry experience and historical reviews to determine aging effects managed by an aging management program. The applicant provided adequate guidance to ensure aging effects are appropriately managed.
Fire Protection Aging Management Program The Fire Protection aging management program is an existing program modified for the purpose of aging management credited with managing the aging effects in the fire barrier system, the diesel driven fire pump, and the Halon and CO2 fire suppression systems in the Three Mile Island Nuclear Station - Unit 1. The aging effects are managed by periodic inspection of fire barrier penetration seals and fire barrier envelop systems, fire barrier walls, ceilings, and floors, and periodic inspection and testing of fire rated doors and dampers. Aging effects are also managed by the periodic inspection and testing of the diesel driven fire pump to ensure that the fuel supply line can perform its intended function. Aging effects for the Halon and CO2 fire suppression systems are managed by performing periodic operability testing and visual walk-downs of the systems.
This program uses existing surveillances and tests to manage aging effects. Existing visual inspections for fire barrier penetration seals, envelop systems, walls, ceilings, and floors are credited along with visual inspections and periodic testing of fire barrier doors and dampers. An enhancement to the program will be made to improve the inspection acceptance criteria for the fire barrier walls, ceilings, and floors, to include degradation due to cracking, spalling, and loss of material caused by freeze-thaw, chemical attack, and reaction with aggregates.
The program credits the existing surveillance tests performed on the diesel driven fire pump to monitor the aging effects on the fuel supply line. These surveillance tests demonstrate that the fuel supply line can deliver sufficient fuel for the pump to meet its intended function. Enhancements to the surveillance test procedure will provide guidance for visual inspection of the diesel fuel supply line for external surface corrosion.
To monitor aging effects of the in scope Halon and CO2 fire suppression systems, existing periodic operability testing and visual walk-downs of the systems are credited.
The operational testing for these systems occur at a frequency of 18 months for the Halon system and 24 months for the CO2 system. These are less frequent than the six month frequency recommended in NUREG-1801.
The inspectors reviewed the existing fire protection program and supporting documents to verify the effectiveness of the program. The inspectors conducted interviews and performed walk-downs of various fire barriers throughout the plant to observe the effectiveness of the existing program. The inspectors also walked down the diesel driven fire pump and the associated fuel supply line and accessible portions of the carbon dioxide suppression system. Surveillance procedures and results were reviewed for completeness and compliance with applicable codes. Program enhancements were reviewed for adequacy and completeness.
An acceptable exception to the NUREG-1801 guidance was noted for frequency of the functional tests of the halon system and carbon dioxide system. NUREG-1801 states that the functional tests for both systems should be performed once every six months.
The Three Mile Island - Unit 1 program specifies performance of the test once every 18 months for halon and once every 24 months for carbon dioxide. This is acceptable, because visual inspections occur on the halon system for system charge testing (storage tank pressure at least every 3 months, and storage tank weight at least every 6 months),and the carbon dioxide system undergoes a visual storage tank level and pressure check at least weekly. Also, there have not been any aging-related events adversely affecting system operation. These conditions have been granted previously by the NRC in license renewal safety evaluation reports as conditions necessary to recognize the frequency in the current licensing basis as acceptable. The inspectors reviewed the systems surveillance and corrective action histories and determined that these conditions were met.
The inspectors concluded the applicant had conducted adequate evaluations as well as industry experience and historical reviews to determine aging effects managed by an aging management program. The applicant provided adequate guidance to ensure aging effects are appropriately managed.
Fire Water System Aging Management Program The Fire Water System aging management program is an existing program modified for the purpose of aging management credited with managing the aging effects from loss of material due to corrosion, microbiologically induced corrosion, or biofouling in water-based fire protection systems in the Three Mile Island Nuclear Station - Unit 1. The aging effects are managed by periodic testing and inspection of systems and components exposed to raw water including sprinklers, nozzles, fittings, valves, hydrants, hose stations, standpipes, water storage tanks, and above ground and underground piping and components.
The program credits existing tests and inspections to monitor the aging effects on the fire water system. Fire system main header flushes are performed annually and fire system main header flow tests are conducted every three years. Fire hydrant hose hydrostatic tests, gasket inspections, and yard fire hydrant flow tests are performed annually. Visual inspections of hydrants for signs of corrosion are also performed annually. Fire pump functional tests are performed every 18 months to confirm adequate discharge flow and pressure. Pressure is maintained by the motor-driven jockey pump and the altitude tank.
Pressure is monitored for low-pressure conditions by an alarm in the main control room and auto start of the three main fire service water pumps and by a low-level alarm on the altitude tank.
The program will be enhanced to include periodic nonintrusive volumetric fire protection piping wall thickness measurements. These nonintrusive inspections will include selected portions of the fire protection system piping located aboveground and exposed to water and will measure the thickness of the pipe wall and the inside diameter of the piping. The inspections will be conducted prior to the end of the current term and repeated on a frequency not exceeding every 10 years.
Sprinkler system visual inspections are performed at least once every refueling outage.
The program will be enhanced to perform sprinkler head sampling in accordance with NFPA 25, "Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems" (1998 Edition), Section 2-3.1. Representative samples of sprinkler heads from in scope sprinkler systems will be submitted to a testing laboratory prior to being in service 50 years. Thereafter, the testing will be repeated on a frequency of once every 10 years.
The inspectors reviewed program bases documents and implementing procedures to assess the effectiveness of the existing program. The inspectors reviewed the implementing procedures for and results of previous periodic flow testing, along with other relevant surveillance results. The inspectors also conducted interviews and performed walk-downs of portions of the fire water system to observe the effectiveness of the existing program. Program enhancements, including draft implementing procedures, were reviewed for adequacy and completeness.
The inspectors concluded the applicant had conducted adequate evaluations as well as industry experience and historical reviews to determine aging effects managed by an aging management program. The applicant provided adequate guidance to ensure aging effects are appropriately managed.
Inaccessible Medium Voltage Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Aging Management Program The Inaccessible Medium Voltage Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements aging management program is a new program credited with managing the aging effects in inaccessible medium-voltage cables that are exposed to significant moisture simultaneously with significant voltage in the Three Mile Island Nuclear Station - Unit 1. The aging effects are managed by periodic inspection for water collection in cable manholes and conduit and draining water as needed. Also, in-scope cables will be periodically tested to provide an indication of the condition of the conductor insulation.
This new program will include periodic inspections of cable manholes containing in scope cables and draining water out of the manholes if needed. These inspections will occur at a six month frequency. These inspections are designed to be a preventative measure for insulation damage due to moisture intrusion and water trees.
The new program will also include cable testing. The first testing will occur before the period of extended operation and will continue at a frequency of every ten years. The method of testing will be determined prior to the first testing and will be a test method proven to determine insulation deterioration, such as power factor, partial discharge, or polarization index testing.
The inspectors reviewed data from previous manhole inspections, including the procedural guidance and results. The inspectors also reviewed the applicants draft plan for managing water intrusion of in scope manholes. The inspectors interviewed relevant applicant personnel regarding how the proposed program will prevent and identify age related deficiencies. The inspectors reviewed draft procedural guidance for cable testing using acceptable testing methods. The inspectors concluded that, if effectively implemented as described in the program description documents, the aging effects in inaccessible medium-voltage cables would be adequately managed.
The inspectors concluded the applicant had conducted adequate evaluations as well as industry experience and historical reviews to determine aging effects managed by an aging management program. The applicant provided adequate guidance to ensure aging effects are appropriately managed.
The Structures Monitoring Program also implements the Masonry Wall Program, and the Water-Control-Structures Inspection Program.
The Structures Monitoring Program at Three Mile Island - Unit 1 is an existing program that is to be further enhanced to meet the requirements and guidance set forth in 10 CFR 50.65, Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, NUMARC 93-01, Industry Guidelines for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, and Regulatory Guide 1.160, Rev. 2, Monitoring the Effectiveness of Maintenance at Nuclear Power Plants. This program is described in Appendix B, Section 2.39 for the license renewal application. Exelon Generation Group, LLC uses the structural monitoring program to monitor the condition of structures and structural components within scope of the Maintenance Rule, thereby providing reasonable assurance that there is no loss of intended function of structure or structural component. The program will be enhanced to include additional structures and structural components identified in the license renewal aging management review. Enhancements to the Exelon Generation Group, LLC Structural Monitoring Program will be implemented prior to the period of extended operation.
The scope of the program also includes condition monitoring of masonry walls and water-control structures as described in the Masonry Wall Program and in the RG 1.127, Inspection of Water-Control Structures Associated With Nuclear Power Plants, aging management program. As a result, the program elements incorporate the requirements of NRC IEB 80-11, Masonry Wall Design, the guidance in NRC IN 87-67, Lessons learned from Regional Inspections of Licensee Actions in Response to IE Bulletin 80-11, and the requirements of NRC Regulatory Guide 1.127, Inspection of Water-Control Structures Associated with Nuclear Power Plants.
Aging effects identified within the scope of the Structures Monitoring Program such as loss of material, cracking, change in material properties, and loss of form are detected by visual inspection of external surfaces prior to the loss of the structures or components intended function.
The inspectors reviewed the Aging Management Program description for the Structural Monitoring Program, the Program Evaluation Document for the Structural Monitoring Program, engineering documents, inspection reports, condition reports, corrective action documents, work request documents, site procedures, and related references used to manage the aging effects on the structures. On August 14, 2008, the inspectors conducted a general walkthrough inspection of the site, including the turbine building, reactor containment building, diesel generator building, control room, the intake structure, and other applicable structures, systems, and components related to the Structural Monitoring Program. The inspectors held discussions with applicants supervisory and technical personnel to verify that areas where signs of degradation, such as spalling, cracking, leakage through concrete walls, corrosion of steel members, deterioration of structural materials and other aging effects, had been identified and documented. Also, the inspectors verified that the applicant maintains appropriate (photographic and/or written) documentation of these inspections to facilitate effective monitoring and trending of structural deficiencies and degradations.
Through the review of documents, walkthrough inspections, and discussions with engineering and plant personnel, the inspector identified some weaknesses in the structural aging management program. The following observations were common to all the three reviewed programs as currently implemented.
A technically acceptable trending system was not implemented to establish the status of observed cracks (stable or active), and qualification and certification of inspectors/examiners was not explicitly established and documented to assure assignment of qualified individuals for inspection. The inspection personnel selection is left to the supervisor of the group. The applicant has initiated a review and revision of all structural inspection and documentation practices as noted in TM-AMRBD-S-2.4.13,19, 20, Rev 1, Ref 5.12 Further Evaluations Summary Report.
Based on the above review, and the applicants efforts to address the observations, the inspectors concluded that the applicant had conducted adequate historic reviews of the plant specific and industry experience to determine aging effects. The applicants proposed amended program will provided adequate guidance to ensure aging effects will be appropriately assessed and managed.
Bolting Integrity Aging Management Program The Bolting Integrity Program is an existing aging management program, as described in Appendix B, Section 2.1.7 for the license renewal application. This program implements bolting monitoring requirements specified by EPRI NP-5067, Good Bolting Practices and maintenance recommendations of EPRI TR-104213, Bolted Joint Maintenance &
Application Guide. The Bolting Integrity Program manages loss of preload, cracking, and loss material due to corrosion of bolts within scope of license renewal. The Bolting Integrity program incorporates NRC and industry recommendations delineated in NUREG-1339, Resolution of Generic Safety Issue 29: Bolting Degradation or Failure in Nuclear Power Plants, Bolted Joint Maintenance & Applications Guide, and EPRI NP 5769, Degradation and Failure of Bolting in Nuclear Power Plants, as part of the comprehensive corporate component pressure retaining bolting program.
The inspectors reviewed the program description and supportive material for the Bolting Integrity Program. This program is implemented through the System Walkdown Program; In-service Inspection (ISI) Program for mechanical bolting; and by the In-service Inspection (ISI) Program - IWF; and the Structures Monitoring Program (SMP) for structural bolting. The inspectors reviewed inspection reports, condition reports, site procedures, drawings, and related references used to manage the aging effects related to most of the programs mentioned above. The applicant presented documentation to support maintenance work and observation related to bolts in structural and mechanical elements. Observed conditions with potential to affect intended functions are, evaluated or corrected in accordance with the corrective action process. The Bolting Integrity Program is consistent with the ten elements of aging management program XI.M18, Bolting Integrity as specified in NUREG-1801, with some exceptions, as mentioned in the program description.
The inspectors concluded that the applicant had conducted adequate historic reviews of plant specific and industry experience to determine, identify, and address aging effects.
The applicant had provided adequate guidance to ensure aging effects will be appropriately assessed and managed.
ASME Section XI Inservice Inspection, Subsections IWB, IWC, and IWD Aging Management Program The Inservice Inspection aging management program is an existing program credited in the license renewal application for managing cracking due to stress corrosion cracking, cracking due to thermal and mechanical loading, cracking due to cyclic loading, and loss of fracture toughness due to thermal aging embitterment. The Three Mile Island - Unit 1 Inservice Inspection program details the requirements for the examination, testing, repair, and replacement of components specified in ASME Section XI Subsections IWB-1100, IWC-1100, and IWD-1100 for Class 1, 2, and 3, respectively, including pressure-retaining piping and components, and their integral attachments. For the current in service inspection interval, the Three Mile Island - Unit 1 program plan applies risk-informed Inservice Inspection alternative requirements to Categories B-F, B-J, C-F-I and C-F-2 for Class 1 and Class 2 piping welds. The Three Mile Island - Unit 1 Inservice Inspection Program Plan for the third ten-year inspection interval effective from April 20, 2001 through April 19, 2011 is based on the 1995 ASME Section XI B&PV Code, including 1996 addenda.
The inspectors reviewed the applicable license renewal evaluation, applicable procedures, reviewed the latest NRC Inservice Inspection program plan, reviewed the latest Inservice Inspection baseline inspection report, and conducted a general review of the Inservice Inspection program with the responsible applicant personnel.
The inspectors concluded that the Inservice Inspection program was in place, included the elements identified in the license renewal application, and that Inservice Inspection activities are being conducted as described in the Inservice Inspection Program.
Reactor Head Closure Studs Aging Management Program The Reactor Head Closure Studs Aging Management Program provides for condition monitoring and preventive activities to manage stud cracking due to stress corrosion cracking and loss of material due to wear, general pitting, and crevice corrosion. It is an existing program that provides for ASME Section XI inspections of reactor head closure studs and stud components. The program is implemented through station procedures based on the examination and inspection requirements of ASME Code,Section XI, Subsection IWB, Table IWB 2500-1, and Regulatory Guide 1.65.
The inspectors reviewed station procedures, interviewed the ISI program manager, concluded that the applicant had provided adequate guidance to ensure the aging effects will be appropriately assessed and managed.
ASME Section XI Inservice Inspection, Subsection IWE Aging Management Program The ASME Section XI, Subsection IWE aging management program is an existing program, credited in the LRA, which provides for inspecting the reactor building liner plate and related components for loss of material, loss of pressure retaining bolting preload, cracking due to cyclic loading, loss of sealing, and leakage through seals, gaskets and moisture barriers in accordance with ASME Section XI. Areas of the reactor building adjacent to the moisture barrier and the moisture barrier are subject to augmented examination.
The inspectors reviewed applicable procedures, the latest Inservice Inspection program and interviewed the Inservice Inspection program manager.
The inspectors concluded that the Inservice Inspection program was in place, had been implemented, was an on-going program subject to NRC review, and included the elements identified in the license renewal application. As it is a currently required program subject to periodic review and inspection, the applicant provided adequate guidance to ensure the aging effects will be appropriately assessed and managed ASME Section XI Inservice Inspection, Subsection IWF Aging Management Program The ASME Section XI, Subsection IWF aging management program is an existing program, which provides for periodic visual examination of ASME Section XI Class 1, 2, and 3 component and piping supports within the scope of license renewal for loss of material and loss of mechanical function due to aging effects. Bolting is also included with these components and is inspected for loss of material and for loss of preload by inspecting for missing, detached, or loosened bolts.
The current licensee Inservice Inspection program is implemented through corporate and station procedures, which provide for visual examination in accordance with the requirements of ASME Section XI, Subsection IWF 1995 Edition with 1996 Addenda as approved by 10 CFR 50.55(a).
The inspectors reviewed procedures, interviewed the Inservice Inspection program manager, and concluded that the ASME Section XI, Subsection IWF aging management was in place, had been implemented, and included the elements identified in the license renewal application. The inspectors further concluded that the applicant will provide adequate planned guidance to ensure the aging affects will be appropriately assessed and managed.
Nickel Alloy Aging Management Program The Three Mile Island - Unit 1 Nickel Alloy Aging Management program is an existing program that manages the aging affects of Alloy 600 components and alloy 82/182 welds in the reactor coolant system. The Three Mile Island - Unit 1 Nickel Alloy Aging Management Program manages cracking due to primary water stress corrosion cracking for nickel alloy components exposed to borated water at elevated temperatures located in the Steam Generator, Reactor Vessel, Reactor Coolant, and Core Flooding system. The components do not include steam generator tubes or secondary side components, reactor vessel internals, or control rod drive mechanism nozzles.
The Nickel Alloy Aging Management program uses a number of inspection techniques to detect cracking due to primary water stress corrosion cracking, including surface examinations, volumetric examinations, and bare metal visual examinations. The Nickel Alloy Aging Management program implements the inspection of components through an augmented in-service inspection program. The augmented program administers component evaluations; examination methods, scheduling, and site documentation as required by regulations, the Code or industry commitments related to nickel alloy issues.
The Nickel Alloy Aging Management program includes mitigation and repair activities and strategies to ensure the long-term operability of nickel alloy components. . Some of the currently available mitigation techniques include weld overlay, replacement with Alloy 690 and Alloy52/152, and half nozzle repair.
The inspectors concluded that the Nickel Alloy Inspection Program was consistent with the description in the LRA and that the applicant had provided adequate guidance to ensure that the aging effects will be appropriately managed.
Open Cycle Cooling Water System Aging Management Program The Open Cycle Cooling aging management program is an existing program credited with managing aging affects such as loss of material, pitting, crevice corrosion, reduction in heat transfer capability, fouling, leaching, and microbiological influenced corrosion in the Main Condenser, Auxiliary Condensers, Main Condenser Air Removal System, Circulating Water System, Nuclear Services River Water, Decay Heat Removal, Reactor Building Emergency Cooling Water, and other systems in Three Mile Island Nuclear Station - Unit 1. The aging effects are managed by various techniques such as chemical treatment for bio-fouling, verification of heat transfer function, routine inspection, cleaning, maintenance, and system walk-downs. These activities will be expanded to include the aging affects on the internal surfaces of concrete circulating water piping.
The Open Cycle Cooling Water System Aging Management Program takes advantage of existing programs to manage the affects of aging. For example the program implements the Raw Water Chemistry Strategic Plan by way of such procedures as the Asiatic Clam and Zebra Mussel Surveillance, and the River and Circulating Water System Macro-Fouling Treatment procedure. The program also includes the elements of GL 89-13 for heat exchanger performance monitoring, such as procedure OP-TM-533-271 and 272, "HTXR Performance Test Procedures".
The inspectors walked-down a large portion of the Open Cycle Cooling Water System and reviewed the current remediation program for Microbiologically Induced Corrosion with the system manager. The program results, condition of the system, maintenance and management programs being currently implemented were compared with the claims made for these programs in the license renewal application. The inspectors determined there was good alignment between the existing programs, the claims made in the application, and current effective management of the affects of aging.
The inspectors concluded the applicant had conducted adequate evaluations as well as industry experience and historical reviews to determine aging effects managed by an aging management program. The applicant provided adequate guidance to ensure aging effects are appropriately managed.
b. Overall Findings The inspection team concluded screening and scoping of non-safety related systems, structures, and components, was implemented as required in 10 CFR 54.4(a)(2), and the aging management portion of the license renewal activities were conducted as described in the License Renewal Application. The inspection results supported a conclusion that the proposed activities will reasonably manage the effects of aging in the systems, structures, and components identified in your application. The inspection concluded the documentation supporting the application was in an auditable and retrievable form.
ATTACHMENT
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
Mike Gallagher, Vice President License Renewal Exelon
Fred Polaski, License Renewal Manager, Exelon
Chris Wilson, Licensing Lead, Exelon TMI License Renewal Team
Al Fulvio, Technical Lead, Exelon TMI License Renewal Team
Ed Fuhrer, Site Lead Exelon TMI License Renewal Team
Mark Miller, Mechanical Exelon TMI License Renewal Team
Stu Getz, Site Lead Exelon TMI License Renewal Team
Dan Christiana, Mechanical Exelon TMI License Renewal Team
Jack Crockroft, Exelon TMI License Renewal Team
Bill Ford, Mechanical Exelon TMI License Renewal Team
Charlotte Geiger, Mechanical Exelon TMI License Renewal Team
Mike Guthrie, TLAA Exelon TMI License Renewal Team
Dep Spamer, Electrical Exelon TMI License Renewal Team
Mike Drago, Civil Exelon TMI License Renewal Team
G. Navratil ISI Program Manager
Rich Sieglitz Fire Protection System Engineer
Ryan Harris Fire Protection System Engineer
Rich Freeman Senior Program Engineer
Chet Shorts Electrical Engineer