NUCLEAR FUEL TECHNOLOGY

Transcription

1 NUCLEA FUEL TECHNOLOGY DEVOTED TO NUCLEA FUELED BY SCIENCE SI-POWE structint.com

2 STUCTUAL INTEGITY ASSOCIATES, INC. DEVOTED TO NUCLEA FUELED BY SCIENCE NUCLEA FUEL TECHNOLOGY The Nuclear Fuel Technology Division is highly experienced in performance evaluations, material modeling, engineering analysis, and software development related to nuclear fuel behavior under normal operating conditions, off-normal transients, and postulated accidents. We have unique experience in all aspects of fuel reload design including core neutronics, thermal-hydraulics, transients and radiological dose analyses. ecognizing the importance of component quality on fuel performance and reliability, we have developed advanced capabilities in the technical assessment and fabrication surveillance of fuel rods and assembly components. We welcome new challenges and urge you to contact us whenever the need arises 24/7/365 2 NUCLEA FUEL TECHNOLOGY

3 -877-4SI-POWE structint.com OU NUCLEA FUEL TECHNOLOGY SEVICES We provide practical and innovative engineering services to assess and improve the performance, reliability and safety of nuclear fuel and associated core components. We are industry experts in nuclear fuel behavior modeling and analyses. Our expertise extends to reload design and analyses as well as NC licensing submittals for fuel driven modifications. We perform fuel engineering support for the entire fuel cycle from fuel fabrication to core design and analysis to plant operation and finally spent fuel storage and transportation. SEVICES Modeling and Software Development for Diagnostic Evaluation of Critical Fuel Performance elated Issues Classic Pellet-Cladding Interaction (PCI), Stress Corrosion Cracking (SCC), and PCI Missing Pellet Surface (MPS) Accidents: eactivity Insertion Accident (IA), and Loss of Coolant Accident Degradation (LOCA) Behavior Failed Fuel Post CHF CILC MPS PCI-SCC Design Basis Transients Cladding esponse to Strong PCMI eload Design and Plant Support Core Design Thermal Hydraulics Analysis Safety Analysis Setpoint Analysis Dose Analysis Startup and Operations Support for Plant Maneuvers SS 6P P 6P P P 6P P 6P Example of fuel pattern that satisfies safety, economy, etc. SS Failure Criteria for Cladding with Mixed Hydride Structure 4 Critical Strain Energy Density (MPa) Circumferential Hydride Concentration (ppm) adial Hydride Concentration (ppm Hydrogen) PCI-isk-Free Power Operations Plant Start-up Power amping Flexible Power Operations and Load Follow Fuel Conditioning and econditioning Operational Guidelines Propagating SCC Fresh Surface upture Defect PCI-SCC Eventual Ductile Fracture 8 K SCC Propagated upture 9 K PCI-SCC+MPS Falcon Simulation Note egion of high stress at ~45º is consistent with observed crack trajectory -35 MPS Embrittling F.P. Species elease Licensing Support for Spent Fuel Dry Storage and Transportation Hydrides eorientation Fuel ods Failure under Hypothetical Accidents Circumferential: 227ppm e-orientated 7ppm adial Stress MPn) Hydrides eorientation Circumferential Mixed Hydrides SED=MPs SED=5.2 MPs Data:.5% Data: 7.5% Strain (m/m) OU NUCLEA FUEL TECHNOLOGY SEVICES 3

4 STUCTUAL INTEGITY ASSOCIATES, INC. NUCLEA FUEL DESIGN AND ELOAD SAFETY ANALYSES 38 UB8 53 UB U48 T72 85 T35 UW2 2 7 T39 UW T32 T63 36 U4 5 UB2 66 UB4 25 UB6 39 UA3 54 T42 69 U5 86 T554 4 UB4 26 U32 4 T59 55 U46 7 T56 87 U UB6 U33 5 UB 5 UA 27 T559 4 U44 56 T55 7 U5 88 T544 3 UA5 4 T545 5 U58 2 T53 2 U52 22 T U T U T4 53 U42 54 T UA7 68 T56 69 U44 83 T UB8 UA9 6 UB 6 T42 28 U42 42 T56 57 T T2 89 U55 6 T52 23 U52 4 T23 55 T57 7 T53 84 U46 96 T46 T62 2 UW 3 UW 4 T U4 T36 T3 T37 U4 UB2 UB U5 T533 UA T55 U52 T48 UA2 UB T542 U53 T549 U54 T555 U43 T532 U3 UB U55 T547 U56 T5 U57 T526 U45 T529 UA4 UB T24 U58 T546 U59 T26 T59 T525 U47 T45 UB T552 T3 T522 T4 T22 U52 T53 U53 U49 T T64 T527 U36 T44 U35 T556 U56 T55 U57 T5 T UW5 T2 T4 P4 T49 T4 T548 U59 T535 UA6 T UW5 T54 U37 T4 U34 T52 U522 T539 U523 T53 T T7 T3 T54 T T528 T2 T28 U526 T57 U527 U T27 U528 T543 U529 T25 T52 T58 U43 T43 UB U53 T5 U53 T537 U532 T55 U45 T52 UA8 UB T58 U533 T536 U534 T54 U47 T534 U3 UB7 97 U T UA 2 T553 2 U T47 23 UA 24 UB9 COE DESIGN OPTIMIZATION Traditionally, core design has been the exclusive area of expertise of fuel vendors. To manage fuel costs, utilities have recognized the value of independent core design and multi-cycle optimization. We have the experience to perform independent core design analysis and optimization resulting in: Significant fuel cost savings by improving fuel utilization Operational flexibility including reduced power operations, and load following Enhanced long term performance from multi-cycle optimization 25 UB2 26 UB2 27 U48 28 T38 29 T3 2 T34 2 U49 22 UB22 23 TB T74 UW UW7 T6 ELOAD SAFETY ANALYSIS The continued evolution of fuel designs, plant operating strategies, and performance goals in the power generation market demands that licensing and safety analysis of nuclear reactors be flexible and responsive. We have the analytical expertise to perform all aspects of fuel reload engineering including: Core thermal hydraulics, design basis transients, setpoints, and accident radiological dose analyses Licensing submittals to provide additional plant safety analysis margins and support power uprates, life extension and Fukushima related activities Temperature (ºC) Time (s). 4 IA Analysis Temperature Distributions 3 2 adial Position (mm) MULTIPLE FUEL VENDO LICENSING AND ANALYSIS Security of fuel supply is an increasing concern in the nuclear power industry. Additionally, fuel costs and engineering support can be improved by having multiple fuel vendors available to supply fuel. Domestic and international fuel vendors will compete for your fuel contracts. Independent fuel reload analysis allows use of fuel from multiple vendors and supports competition. Our personnel have orchestrated licensing of multiple fuel vendors and fuel vendor transitions, including: Financial impact assessments of multiple fuel suppliers Optimized core designs for multiple fuel types Detailed mixed core thermal hydraulic and fuel performance analyses Impact assessments on existing reload analysis methodologies Independent review of fuel vendor specific reports and analyses 4 NUCLEA FUEL DESIGN AND ELOAD SAFETY ANALYSES

5 -877-4SI-POWE structint.com.3.25 Axial Position (m) Hoop Stress (8.36 h) adial Position (m) adial Position (m) -2.E E+ 3.96E E+ 2.44E E=2-2.E E+ 3.96E E+ 2.44E E=2 Clad Element Hoop Stress (MPa) Clad Element Hoop Stress (MPa) od Deformation; Cladding Stress Distribution FUEL BEHAVIO MODELING AND ANALYSIS SI s Nuclear Fuel Technology (NFT) Division has developed and contributed to some of the most robust and cutting edge computational technology for fuel performance analysis in the industry for over 4 years under the sponsorship of research and governmental organizations such as EPI and the Department of Energy (DOE). Development of power ramp rate restrictions and operational guidance for commercial utilities to mitigate fuel rod failure due to Missing Pellet Surface (MPS)- induced Pellet Cladding Interaction (PCI) Analysis for Crud-Induced Localized Corrosion (CILC)- affected BW fuel during normal operation Key member of the Industry Task Force on eactivity Initiated Accidents (IA) Key participant in the Nuclear egulatory Commission (NC) Expert Panel that developed the Phenomena Identification and anking Tables (PIT) review document for BW Anticipated Transient Without Scram (ATWS) Power Oscillation Event, PW Control od Ejection Accident (EA), BW/PW Loss of Coolant Accident (LOCA) Key technical participant for industry response to NC rulemaking on IA and LOCA Primary contractor to EPI for development of Pellet- Cladding Interaction (PCI) Fuel eliability Guidelines Leading participant in EPI-sponsored programs related to Flexible and Extended educed Power Operations (FPO, EPO) Assessment of proposed advanced and accident tolerant fuel (ATF) designs Spent fuel rod integrity during handling and transportation FUEL BEHAVIO MODELING AND ANALYSIS 5

6 STUCTUAL INTEGITY ASSOCIATES, INC. NUCLEA FUEL PEFOMANCE CODE DEVELOPMENT Our Nuclear Fuel group is the industry leader in fuel performance code development. Our staff has developed cutting edge fuel performance tools for EPI and DOE and provided training and independent analyses throughout the industry in the Americas, Europe, and Asia. Under contract to EPI, NFT pioneered the use of advanced thermo-mechanical techniques for fuel performance analysis in the development of the FEY code, the first fully 2D, thermo-mechanical, finite element (FE)-based nuclear fuel performance code for transient analysis. The FEY architecture was also used as the basis for the DEFECT code, a computational tool, unique in the industry, for post primary failure analysis and assessment for suppression of secondary fuel rod failures in BWs. The next significant fuel performance code developed by SI for EPI was the Falcon code. Key Falcon items of interest are: Used for both steady state and transient analyses simultaneously providing the capability to address fuel rod behavior during normal operation, power maneuvers, and postulated accidents Applied to PCI SCC and MPS rod failure assessment, IA, LOCA, FPO and EPO NFT is also now working on 3D, FE-based computational tools for fuel performance analysis and since 22 has been contracted by the Department of Energy as a contributing developer to the NEAMS, BISON and Consortium for Advanced Simulation of Light Water eactors (CASL) programs. Participation in these leading-edge programs demonstrate the wide-ranging experience and expertise of NFT staff and our contributions of critical technologies to the nuclear fuel industry T (K).27e e e e+2 8.e+2 C BISON Fuel Modeling 6 NUCLEA FUEL PEFOMANCE CODE DEVELOPMENT

7 -877-4SI-POWE structint.com NUCLEA FUEL TECHNOLOGY APPLICATIONS - PCI NFT has provided pioneering expertise to the nuclear industry in the evaluation of Pellet-cladding interaction (PCI) fuel failures. Maximum Cladding Hoop Stress (ksi) Nodal Power (kw/ft) Power and burnup dependent bounding analysis 25 2 Nodal Burnup (GWd/tU) Operational Experience NFT developed the computational tools and methodology to evaluate and mitigate potential fuel rod failures due to PCI and MPS-enhanced PCI in LWs. Worked with utilities to assess margin to failure based on their current and proposed operating strategies including evaluation of startup strategies, alternative fuel designs, manufacturing defects, and equipment outages Provided operational guidance to mitigate and eliminate PCI-type fuel rod failures NFT was the primary contractor for EPI that developed the fuel reliability guidelines for use by utility personnel and industry oversight organizations PCI failure mitigation in BW and PW fuel designs through the development of improved power maneuvering procedures Based on this experience, NFT has developed and provides training seminars to utility staff to enhance their awareness and understanding of PCI-type failures. Clad Inner Surface Hoop Stress (Avg) and Cum Damage Index History Clad Element Hoop Stress (MPa) Clad Inner Surface Element Clad Hoop Stress (MPa) Clad Inner Surface Element Clad Cum Damage Index Position (m) Time (h) -2.36E E+ 9.6E+ 2.62E E E+2 NUCLEA FUEL TECHNOLOGY APPLICATIONS - PCI 7

8 STUCTUAL INTEGITY ASSOCIATES, INC. DEVELOPMENT OF INDUSTY FUEL ELIABILITY GUIDELINES In support of the nuclear industry s initiative to eliminate fuel failures, we worked with the Electric Power esearch Institute (EPI) to develop the following important fuel reliability guidelines for use by utility personnel and industry oversight organizations: Fuel surveillance and inspection programs to identify and assess trends in key fuel performance characteristics for currently operating reactors, following changes in fuel design, manufacture and operation, or after anomalous plant operational conditions. Pellet-cladding interaction (PCI) failure mitigation in BW and PW fuel designs through the development of improved power maneuvering procedures. Grid-to-rod fretting fuel failure recommendations to eliminate failures through improvements in debris mitigation features in fuel designs, core design modifications, and fuel spacer grid design improvements. These guidelines have been used by Utility personnel and industry oversight organizations not only to enhance their understanding of the issues but to also assess and improve the performance of their fuel. 9 8 Original Plan Extended Low Power # rods in this region % % 5% 2% 25% 3% 35% 4% 45% 5% 55% 6% 65% % Through Wall 7% 75% 8% 85% 9% 95% % 5% % Grid-to od Fretting Wear Trends - Assuming 3rd cycle increase from 6 to 67 days at flow Grid to od Fretting Indication 8 DEVELOPMENT OF INDUSTY FUEL ELIABILITY GUIDELINES

9 -877-4SI-POWE structint.com NUCLEA FUEL MECHANICAL DESIGN Whether to extend current capabilities or remedy in-core reliability issues, the risks of introducing new fuel design features or new materials can be quite severe. These risks include failure to meet performance or operational expectations, introduction of unexpected reliability issues, and in the worst case, fuel failures. Given these risks, it is imperative to independently assess supplier changes to existing designs and materials prior to introduction into the core. This third-party assessment includes review of: SI s unparalleled, specialized, global experience in this area includes design review for the following: Advanced BW, PW and VVE designs Structural design of fuel assembly and core components for an advanced reactor concept Material evaluations of advanced cladding alloys Supplier design packages Mechanical and seismic test requirements, criteria, and reports In-core performance databases Lead test program post-irradiation examination results Past performance of similar features NUCLEA FUEL MECHANICAL DESIGN 9

10 STUCTUAL INTEGITY ASSOCIATES, INC. SPENT FUEL STOAGE AND TANSPOTATION With the increasing frequency of nuclear plant shutdowns, decommissioning of power plant sites is becoming a new focus area in the industry. Decommissioning and emergency response reduction licensing submittals, spent fuel pool islanding and dry cask canister design verifications are becoming familiar terms at nuclear plant sites. Our staff have the knowledge and expertise to perform and review all fuel related analysis in this area, including dry cask storage loading patterns, heat load analyses and dose calculations, and safety analyses of spent fuel systems under storage and transport conditions prescribed in CF 7 & 72. In offering these services, we rely on our staff s extensive experience in spent fuel technology as described below. The Structural Integrity Nuclear Fuel Technology Group began their spent fuel activities in the early 99s as members of an expert team selected by SANDIA National Laboratory for the development of the well-known cask containment requirements report SAND9-246, November 992. Building on that report, the SI team, under contract to EPI since the year 2, have carried the research further to deal with high burnup fuel issues, developing methods to quantify threats to cladding integrity during drop accidents. Such threats stem from cladding loss of ductility during high-burnup operation and the evaluation of damage mechanisms, such as hydride re-orientation, during long-term dry storage. SI s research in this area, which is still continuing, has produced a large volume of original work, which include position papers submitted to the NC for review on topics such as the characterization of failure mechanisms and associated failure criteria, and the response analysis of spent fuel systems subjected to normal and hypothetical accident conditions as prescribed in CF 7. The following is a synopsis in pictures that selectively highlights SI s spent fuel experience. Assembly Distortion Maximum esponse SED VALUE -3.27E E E E E E E E E E E E E E+8 SED VALUE -5.3E E E+8 -.3E E E E+8 +4.E E E+8 +8.E E+8 +.7E+9 +.2E+9 SED VALUE -7.25E E E E E+8 +2.E+7 +.7E E E E E E+8 +.7E E+9.-ms.54-ms 4.-ms Hypothetical Transportation Accident: 9-m Cask-Drop Guide Tube esponse: Green Color Indicates the Extent of Fracture TITLE SPENT FUEL STOAGE AND TANSPOTATION

11 -877-4SI-POWE structint.com Spent Fuel esponse Analysis & Failure Probabilities Under 9-m Drop Pinch Force (lb) Time (s) Cumulative Distribution Function SED or CSED (MPa).2 SED CSED.4.6 P F =2.47%.8 Cumulative Distribution Function SED or CSED (MPa).2 SED CSED.4.6 P F =.6%.8 Cask Drop Simulation showing assembly econfigurations Maximum Pinch Force Time Histories Failure Probability IFBA/Standard Fuel Training Distribution Failure Mode Crack Transverse Tearing Strain Distribution 2 (P f ) ID < 2% (P f ) ID-OD 2% od Breakage od Interaction Load SECTION A-A Longitudinal Tearing Internal Pressure PCI Crack Internal Pressure 3 SED VALUE -5.53E E E+6 -.7E E E E+6 +7.E E+6 +.7E E E+7 +.6E E+7 (P f ) ID < 2% (P f ) ID-OD 2% Axial Stress SED VALUE -7.7E+8-6.9E+8-5.2E E E E+8-7.3E E E E E E E E+8 Zero Axial Strain SED VALUE -. 3E E E E E E E E E E E E E E-2 Fuel ods Failure Modes During Cask Drop Cladding Failure Probabilities at ID & OD Guide Tube Partial Failure 2e+7-2e+7-4e+7-6e e+7 Fuel adial Stress at 4 C & Pressurized Cracks adial Stress in Fuel Pellet with Pressurized Cracks Spent Fuel with Fuel-Cladding Bonding In Dry Storage adial Stress (Pa).3e+8 3.2e+7.3e+8.2e+8.e+8 e e+7 Cladding hoop stress at 4 C at zero hold time 6.77e+7 Cladding hoop stress at 4 C After 6-day hold 6e+7 5e+7 4e+7 3e+7 2.6e+7 Cladding Hoop Stress During 6-day Hold at 4ºC after Vacuum Drying SPENT FUEL STOAGE AND TANSPOTATION

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