ASTM E1018-20e1

4.1 The ENDF/B library in the United States and similar libraries elsewhere, such as JEFF (23), JENDL (21), and BROND (22), provide a compilation of neutron cross section and other nuclear data for use by the nuclear community. The availability of these excellent evaluations makes possible standardized usage, thereby allowing easy referencing and intercomparisons of calculations. However, as the first ENDF/B files were developed it became apparent that they were not adequate for all applications. This need resulted in the development of the specialized ENDF/B Dosimetry File 4.2 The application to LWR surveillance dosimetry introduced new data needs that can best be satisfied by the creation of a dedicated cross section file. This file shall be maintained in a form designed for easy application by users (minimal processing). The file shall continue to incorporate the following types of information or indicate the sources of the following type of data that should be used to supplement the file contents:

4.3 The ASTM-recommended cross sections and uncertainties are based mostly on the IRDFF (version 1.05) dosimetry files. Damage cross sections for materials such as iron have been added in order to promote standardization of reported dpa measurements within the dosimetry community. Integral measurements from benchmark fields and reactor test regions have been considered in order to ensure self-consistency 1.1 This guide covers the establishment and use of an ASTM evaluated nuclear data cross section and uncertainty file for analysis of single or multiple sensor measurements in neutron fields related to light water reactor LWR-Pressure Vessel Surveillance (PVS). These fields include in- and ex-vessel surveillance positions in operating power reactors, benchmark fields, and reactor test regions.

1.2 Requirements for establishment of ASTM-recommended cross section files address data format, evaluation requirements, validation in benchmark fields, evaluation of error estimates (covariance file), and documentation. A further requirement for components of the ASTM-recommended cross section file is their internal consistency when combined with sensor measurements and used to determine a neutron spectrum.

1.3 Specifications for use include energy region of applicability, data processing requirements, and application of uncertainties.

1.4 This guide is directly related to and should be used primarily in conjunction with Guides E482 and E944, and Practices E560, E185, and E693.

1.5 The ASTM cross section and uncertainty file represents a generally available data set for use in sensor set analysis. However, the availability of this data set does not preclude the use of other validated data, either proprietary or nonproprietary. When alternate cross section files that deviate from the requirements laid out in this standard are used, the deviations should be noted to the customer of the dosimetry application.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.