Activities of the OECD/ NEA Expert Group on Assay Data for Spent Nuclear Fuel

Transcription

1 Activities of the OECD/ NEA Expert Group on Assay Data for Spent Nuclear Fuel International Workshop on Advances in Applications of Burnup Credit 27 October 2009 Ian Gauld Yolanda Rugama

2 Overview Background Formation of the Expert Group Objectives Status Update on the isotopic assay database Preparation of a state-of-the-art report on assay data by the Expert Group Current activities and next steps 2 Managed by UT-Battelle

3 Expert Group on Assay Data for Spent Nuclear Fuel (EGADSNF) Formed in 2007 by EGBUC as a working group of the WPNCS Initially chaired by K. Suyama (formerly with JAEA) Address wide interest in isotopic assay data to support validation of burnup credit and other safety-related applications Working group includes members from WPNCS, the standing technical Committee on the Safety of Nuclear Installations, the Integration Group for the Safety Case of the Radioactive Waste Management Committee, experts in radiochemistry Members from Belgium, Czech Republic, Finland, France, Germany, Hungary, Japan, Slovak Republic, Spain, Sweden, Switzerland, United Kingdom, and the United States Third meeting held in June 2009 Currently chaired by I. Gauld (ORNL) Meeting attended by 27 participants representing 12 countries 3 Managed by UT-Battelle

4 Motivation for the EGADSNF Countries moving beyond burnup credit R&D to implementation, or expanded implementation, have highlighted need for improved validation data Lack of adequate experimental data for fission products has been an impediment to use of fission products in burnup credit analyses Performing new measurements is an extremely expensive and challenging undertaking Transportation costs Facilities for cutting and waste disposal issues Instrumentation and technical know-how of radiochemistry The EGADSNF aims to take maximum advantage of existing experimental data through better dissemination, improved documentation, and peer review, and serve as a central repository for public data 4 Managed by UT-Battelle

5 Spent Fuel Isotopic Assay Data is Required for Burnup Code Validation Isotopic validation may involve computing the mean bias and uncertainty in calculated isotopic concentration Eu Comparisons between isotopic calculations and experiment Calvert Cliffs-1 - KRI Takahama-3 - JAERI TMI-1 - GE/VNC TMI-1 - ANL ARIANE(GU4) - ITU MALIBU(GGU2), ARIANE(GU3), REBUS, ARIANE(GU1) - SCK/CEN Vandellos II - Studsvik Bias characterizes the average difference between calculated (C) and measured (M) isotopic content Uncertainty represents the variability of the difference between C and M (C/E-1) (%) bias probability distribution burnup (GWd/MTU) The experimental and calculation errors both contribute to the net bias and uncertainty 5 Managed by UT-Battelle

6 Major Activities of the Expert Group Update and expand the electronic database of spent fuel assay measurements (SFCOMPO) Provide users access to primary experimental reports Include benchmark analysis reports when available Include more recent experiments Expand to include non-lwr data (e.g., Magnox, VVER, AGR) Include MOX experimental data Update and improve formats Prepare a state-of-the-art report on the status of assay data for spent nuclear fuel first draft completed May 2009 final draft in November Managed by UT-Battelle

7 State-of-the-Art Report Contents Report includes chapters on: Requirements for assay data (for different applications) Important isotopes Reports on country activities New measurement data being contributed and compiled Recommended state-of-the-art experimental methods, best practices, lessons learned Evaluation of impact of uncertainties associated with input data and modeling 7 Managed by UT-Battelle

8 State-of-the-Art Report Requirements for Assay Data Nuclear Criticality Safety OECD/NEA code benchmarks Important actinide and fission products Nuclear Waste Management Waste disposal assessments Longer-lived and mobile fission products Isotopes of high interest to disposal of spent fuel and vitrified high level waste indentified by international organizations Nuclear Fuel and Fuel Cycle Safety Safety analyses based on radiological properties of spent fuel for fuel handling, storage, transportation, and recycling 8 Managed by UT-Battelle

9 Important Isotopes for Decay Heat Analysis Typical LWR fuel Am 144 Pr 106 Rh 242 Cm 240 Pu Fraction of total heat (percent) Ce 125 Sb 244 Cm 154 Eu 147 Pm 134 Cs 90 Sr 137 Cs 90 Y 238 Pu 239 Pu 137m Ba 241 Pu Decay time (years) 9 Managed by UT-Battelle

10 State-of-the-Art Report SFCOMPO A Database of Spent Fuel Isotopic Compositions Web database maintained by the NEA Data Bank New experimental data being contributed by NEA member countries New experimental programs Previous experiments not captured Contributions expand the number of samples from 246 to more than 400 samples New data generally more extensively characterized (isotopic) and better documented ARIANE International Program (Gosgen LEU and MOX) UK reactor fuel data MAGNOX and AGR VVER data from ISTC Project High burnup PWR data from the Spanish Vandellos NPP New BWR data from Sweden and Japan Three Mile Island Unit 1 PWR data REBUS International Program (Neckarwestheim GKN II LEU) 10 Managed by UT-Battelle

11 Spent Fuel Assay Data Currently in SFCOMPO Reactor Country Type Assembly Design Fuel Type Number of Samples Obrigheim Germany PWR UO 2 23 Gundremmingen Germany BWR 6 6 UO 2 12 Trino Vercellese Italy PWR UO 2 39 JPDR Japan BWR 6 6 UO 2 30 Tsuruga-1 Japan BWR 7 7 UO 2 10 Fukushima-Daiich-3 Japan BWR 8 8 UO 2,UO 2 -Gd 2 O 3 36 Fukushima-Daini-2 Japan BWR 8 8 UO 2,UO 2 -Gd 2 O 3 18 Mihama-3 Japan PWR UO 2 9 Genkai-1 Japan PWR UO 2 2 Takahama-3 Japan PWR UO 2,UO 2 -Gd 2 O 3 16 Cooper USA BWR 7 7 UO 2 6 Monticello USA BWR 8 8 UO 2,UO 2 -Gd 2 O 3 30 Calvert Cliffs No.1 USA PWR UO 2 9 H.B. Robinson Unit 2 USA PWR UO Managed by UT-Battelle

12 New Experimental Data to be Included in SFCOMPO Country of Reactor Name Reactor Measurement Assembly Number of 235 U Burnup Reactor Type Facility Design Samples Enrichment [wt%] [GWd/t] Germany Obrigheim PWR ITU/IAEA/WAC/IRCh 14x14 5* Obrigheim PWR ITU 14x Pu-fis 37 Fukushima-Daini-2 BWR NFD 8x (assembly average) 9-62 Japan Fukushima-Daini-1 BWR JAEA 9x (assembly average) NFD 9x (assembly average) Tsuruga-1 BWR NFD 8x /4.6Pu Not yet opened PWR JAEA 17x Netherlands Dodewaard (ARIANE) BWR SCK CEN/PSI 6x /6.4Pu Spain Vandellós PWR Studsvik Nuclear 17x Sweden Forsmark 3 BWR Studsvik Nuclear, Dimitrovgrad, Harwell SVEA Switzerland Beznau-1 (ARIANE) PWR SCK CEN/PSI 14x Pu Gosgen (ARIANE) ITU/SCK CEN 15x / Beznau-1 (UK) ITU/ Karlsruhe 14x Pu Hinkley R3/R4 AGR AERE Harwell/AEE Winfrith Annular UK Hunterston AGR AERE Harwell/AEE Winfrith Annular Hunterston Magnox AERE Harwell Fuel rod Bradwell Magnox AERE Harwell Fuel rod USA TMI-1 PWR GE-Vallecitos x15 Argonne Russia Novovoronezh VVER- (ISTC-2670) 440 RIAR (Russia) Hexagonal Managed by UT-Battelle

13 PWR Experimental Data Illustrating Range of Measured Isotopic Data for Burnup Credit 80 Burnup (GWd/MTU) Calvert Cliffs Turkey Point - Robinson Calvert Cliffs Calvert Cliffs Obrigheim Yankee ARIANE REBUS TMI-1 Takahama MALIBU Vandellos Typical spent fuel cask loading curves 20 Trino TMI Trino Initial Enrichment (Wt% U-235) Actinide sets Partial FP sets Full isotopic sets Principal Isotope Actinide Only 13 Managed by UT-Battelle

14 State-of-the-Art Report Required Data for Benchmark Calculations Define information needed in order to perform a high quality benchmark calculations Design and irradiation history information Design data Reactor information (core layout) Assembly design and dimensions Fuel design and configuration Irradiation conditions Burnup information Coolant data Temperatures Soluble boron Void fraction data Control rod insertions 14 Managed by UT-Battelle

15 State-of-the-Art Report Sensitivity Input Data Uncertainty Takahama-3 PWR used as a reference model (CEA and JAEA studies) Sensitivity to modeling parameters: Assembly pitch Assembly surroundings (neighbor assemblies) Fuel and moderator temperature Irradiation history detail X RODI RODII X X RODIII X RODIV X SF97 15 Managed by UT-Battelle

16 State-of-the-Art Report Sensitivity of Modeling Uncertainty Takahama-3 isotopic sensitivity of edge rods to characteristics of neighbor assembly (unknown) (NRI Rez study) VS. 16 Managed by UT-Battelle

17 State-of-the-Art Report Methods and Techniques for Radiochemical Analysis Important contribution compiling program management and isotope measurement experience of Belgonucleaire, SCK CEN, ITU, CEA, Studsvik An overview of the complete analytical process given, including: Sampling and sample dissolution Separations Measurement techniques and instrument capabilities Uncertainties in the experimental results Best practices and lessons learned Source Glove box High-voltage power supply Vacuum control Source control Filament power supply Magnetic field power supply Magnetic sector Hall probe Hall probe controller I n t e r f a c e Analog-digital converter Ion pump Detection counts 4E+4 3E+4 Cm-243/Cm Pu Am PC mode ANALOG mode E E+4 Pu-239/Pu240 Pu-238/Am-241 Cm U Pu Pu Pu Pu Am Am Cm Cm Cm Cm Managed by UT-Battelle International Workshop Channel on Advances in Applications of Burnup Credit

18 Future Activities of the EGADSNF Peer review and evaluation of the experimental data Currently most public isotopic assay data is largely unreviewed and documentation is inconsistent Little quality assurance of data Some data contains errors and erratic measurement results Experiments are not completely documented what kinds of missing information will preclude use of the data for code validation? Review and processing of the experimental measurements into usable data formats can be very time consuming and must be done by each individual organization utilizing the measurements Review for completeness/accuracy of data required for validation calculations (e.g. reactor operating history and design data) Examples of review procedures available from International Criticality Safety Benchmark Evaluation Project (ICSBE); Evaluated Reactor Physics Experiments Evaluation Project (IRPhEP) Working group experts will initially evaluate two data sets to (activity supported by CSN): identify issues and develop guidance and establish required level of effort moving forward 18 Managed by UT-Battelle

19 Publications on EGADSNF Activities Publications on Expert Group Progress and Activities ICAPP 2009 Global 2009 International Workshop on Advances in Application of Burnup Credit 2009 ANS Winter Meeting Managed by UT-Battelle

20 20 Managed by UT-Battelle Questions?