© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 1 WPEC/SG39 Short updates on neutron propagation experiments, STEK, CIELO status O.Cabellos NEA Data Bank

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 2 ACTION: STEK experiments: Action to be reviewed in future Regarding availability of resources: -NRG activities related to STEK experiment to be clarified/defined in Proposal of transfer STEK models to the SG39 members (TBD) STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 3 STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39 ACTION: Starting from CIELO new files (with uncertainties) attempt new adjustment  Selection of integral experiments (old and new ones)  Use of improved criteria for reliability (as result of methodology studies)  A-posteriori covariance data: proposals on how to use them in evaluation  Need more complete covariance information (e.g. U- 235 data), possibly cross correlations For this point, any future action should be agreed with the CIELO group, in order to check interest and to define a possible schedule. Feedback from CIELO expected.

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 4 Consultant's Meeting on Compensating Effects due to Nuclear Reaction and Material Cross Correlations in Integral Benchmarks. Part of the IAEA activity on the CIELO project (OECD/NEA SG-40). 28 September - 1 October 2015, IAEA, Vienna Objectives  Identify the most common compensating effects in reaction cross sections and cross-material correlations.  Define methodology for selecting a list of benchmarks that can be used to test specific sets of correlations.  Define input files for MCNP for the selected benchmarks. AuthorTitle A. TrkovOn the Compensating Effects in the Evaluated Cross Sections of 235U O. CabellosCompensating Effects due to Nuclear Reaction and Material Cross Correlations D. BernardDecompensating effects in nuclear data integral benchmarking A. KahlerLANL Experience using ICSBEP Benchmarks for Cross Section Data Testing Liu PingBenchmarks for Data Testing of Iron V. PronyaevUncertainties of the Evaluated Nuclear Data and Compensation Effects in the Criticality Go ChibaSensitivity analysis of CIELO test files for fast neutron systems Go ChibaExercise of nuclear data adjustment with fast neutron systems integral data Go ChibaApplication of sub-space method for nuclear data validation STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 5 STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39 Exercise with constraints in nuclear data

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 6 STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39 Change in 235U(n,inel)=MT4: “-9%” in all energy groups)

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 7 STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39 Change in 235U(n,inel)=MT4: “-9%” in all energy groups)

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 8 STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39 Criteria for Clean Experiments (3724 ICSBEP SDFs)  Summing up square sensitivity for isotope and FAST energy range (E> 100 keV):  Ratio of square sensitivity for isotope and energy range: CASES: Pu TOTN_MAT PU-MET-FAST ,910,0299,92 PU-MET-FAST ,790,1499,92 PU-MET-FAST S99,790,1599,92 PU-MET-FAST ,790,1499,92 PU-MET-FAST ,790,1499,92 PU-MET-FAST ,790,1499,92 PU-MET-FAST ,680,27100,02 PU-MET-FAST ,670,2799,92 PU-MET-FAST ,670,2799,92 PU-MET-FAST ,670,2799,92 CASES: U TOTN_MAT HEU-MET-FAST ,610,040,01099,73 HEU-MET-FAST ,610,010,02099,63 HEU-MET-FAST ,60,010,02099,63 HEU-MET-FAST ,60,040,01099,73 HEU-MET-FAST ,590,050,01099,73 HEU-MET-FAST ,590,040,01099,63 HEU-MET-FAST ,580,040,01099,63 HEU-MET-FAST ,580,050,01099,63 HEU-MET-FAST ,580,060,01099,73 HEU-MET-FAST ,580,010,02 99,64 Example: FAST energy range

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 9 STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39 CIELO approach to evaluations To use the best physics, make sure that the models represent the available differential data and use integral data as guidance to set the less-well known parameters, without any attempt to constrain the uncertainties. This is not “fitting” but just an educated guess to prepare a good starting point for a subsequent LSQ analysis, in which the uncertainties will be applied. CIELO is still at the stage of “polishing” the mean values and did not get to the covariances yet. Next meetings planned for 2016: 9-13 May:WPEC /SG40 Meeting Paris, France May:IAEA CM on Current Status and Open Issues in the U-235 Evaluation, Vienna, Austria October: IAEA/TM on Integral Data in Nuclear Data Evaluation 5-9 December: IAEA/TM on CIELO Network

© 2013 Organisation for Economic Co-operation and Development © 2015 Organisation for Economic Co-operation and Development 10 Provide feedback (including Am-241 issue) to be used in the frame of ND activities towards MA improvement requirements (NSC Expert group). Action: Secretariat to suggest most appropriate form of communication. STEK exp. CIELO files –Selection Bench. –Methodologies –Covariance data –Next Meetings MA improv SG39