Generalized Nuclear Data: A New Structure (with Supporting Infrastructure) for Handling Nuclear Data

Abstract

The Evaluated Nuclear Data File (ENDF) format was designed in the 1960s to accommodate neutron reaction data to support nuclear engineering applications in power, national security and criticality safety. Over the years, the scope of the format has been extended to handle many other kinds of data including charged particle, decay, atomic, photo-nuclear and thermal neutron scattering. Although ENDF has wide acceptance and support for many data types, its limited support for correlated particle emission, limited numeric precision, and general lack of extensibility mean that the nuclear data community cannot take advantage of many emerging opportunities. More generally, the ENDF format provides an unfriendly environment that makes it difficult for new data evaluators and users to create and access nuclear data.The Cross Section Evaluation Working Group (CSEWG) has begun the design of a new Generalized Nuclear Data (or 'GND') structure, meant to replace older formats with a hierarchy that mirrors the underlying physics, and is aligned with modern coding and database practices.In support of this new structure, Lawrence Livermore National Laboratory (LLNL) has updated its nuclear data/reactions management package Fudge to handle GND structured nuclear data. Fudge provides tools for converting both the latest ENDF format (ENDF-6) and the LLNL Evaluated Nuclear Data Library (ENDL) format to and from GND, as well as for visualizing, modifying and processing (i.e., converting evaluated nuclear data into a form more suitable to transport codes) GND structured nuclear data.GND defines the structure needed for storing nuclear data evaluations and the type of data that needs to be stored. But unlike ENDF and ENDL, GND does not define how the data are to be stored in a file. Currently, Fudge writes the structured GND data to a file using the eXtensible Markup Language (XML), as it is ASCII based and can be viewed with any text editor. XML is a meta-language, meaning that it has a primitive set of definitions for representing hierarchical data/text in a file. Other meta-languages, like HDF5 which stores the data in binary form, can also be used to store GND in a file.In this paper, we will present an overview of the new GND data structures along with associated tools in Fudge.

CALMAR: A New Versatile Code Library for Adjustment from Measurements

“…Modern programming languages allows this flexibility. This is one of the features of the new Generalized Nuclear Data (GND, [15]) format for libraries. This new format has the following features:…”

Ionization and scintillation of nuclear recoils in gaseous xenon

“…Our calculations follow those of [41][42][43], and make use of ðα; nÞ cross-sections from the Japanese Evaluated Nuclear Data Library (JENDL) [44] and neutron-xenon scattering crosssections from the Evaluated Nuclear Data File (ENDF) [38]. The cross-sections were processed using the tools developed in [45]. Table A1 gives information on the decays of isotopes 238 Pu and 241 Am used as α-emitters in the sources used in this study.…”

Development and verification of a new nuclear data processing system FRENDY

“…Recently, changing the nuclear data format is considered by adopting the Generalized Nuclear Data (GND) format [17] by utilizing the Extensible Markup Language (XML). Since the GND format is completely different from the current ENDF-6 format [18] which was defined several decades ago, the current widely used nuclear data processing systems, e.g., NJOY and PREPRO, cannot treat such a new format without extensive modification.…”