Checking, processing and verification of nuclear data covariances

The aim of this paper is to present the activities carried out by NEA Data Bank on checking, processing and verification of covariances. A picture of the completeness and status of the JEFF- covariances is addressed. | Checking processing and verification of nuclear data covariances EPJ Nuclear Sci. Technol. 4 39 2018 Nuclear Sciences O. Cabellos et al. published by EDP Sciences 2018 amp Technologies https epjn 2018028 Available online at https REGULAR ARTICLE Checking processing and verification of nuclear data covariances Oscar Cabellos James Dyrda and Nicolas Soppera OECD NEA Boulogne-Billancourt France Received 30 October 2017 Received in final form 17 January 2018 Accepted 14 May 2018 Abstract. The aim of this paper is to present the activities carried out by NEA Data Bank on checking processing and verification of covariances. A picture of the completeness and status of the JEFF- covariances is addressed. The verification of covariances is performed with nuclear data sensitivity tool providing the keff uncertainty as a function of the contributing nuclide-reaction pairings including cross-reaction covariances. A total number of 4501 ICSBEP benchmarks is used in this analysis. This exercise is also extended to covariance libraries such as updated files ENDF and ENDF allowing comparison of these results with both the experimental criticality benchmark and different methodologies of evaluation. 1 Introduction covariances MF31 MF32 MF33 MF34 and MF35 are processed using the code 10 formatting 1 is a fully consistent and complete nuclear and processing issues will be discussed in the paper. data library with all data needed and associated covariance The performance of covariance library in information full covariance information for the main criticality and safety analysis is outlined in Section 5. actinides which can be reliably used for a large spectrum Nuclear data sensitivity tool NDaST 11 is able to of applications and which has shown a better performance propagate the covariance of nuclear data in 4501 ICSBEP than library 2 . Previous