BS ISO 18075:2018 pdf download

BS ISO 18075:2018 pdf download.Steady-state neutronics methods for power- reactor analysis
1 Scope
This document provides guidance for performing and validating the sequence of steady-state
calculations leading to prediction, in all types of operating UO 2 -fuel commercial nuclear reactors, of:
— reaction-rate spatial distributions;
— reactivity;
— change of nuclide compositions with time.
The document provides:
a) guidance for the selection of computational methods;
b) criteria for verification and validation of calculation methods used by reactor core analysts;
c) criteria for evaluation of accuracy and range of applicability of data and methods;
d) requirements for documentation of the preceding.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1 Terms
3.1.1 application-dependent multigroup discrete energy-group structure that is intermediate between the application-independent multigroup structure and a few-group structure Note 1 to entry: The application-dependent multigroup structure can be such that the group constants are dependent on reactor composition through an estimated neutron energy spectrum. An application dependent Multigroup data set is one type of averaged data set.
3.1.2 application-independent multigroup discrete energy-group structure that is sufficiently detailed that the group constants may be considered as being independent of reactor composition, geometry, or spectrum for a wide range of reactor analysis Note 1 to entry: The application-independent multigroup structure can be employed directly in reactor- design spectrum calculations, or it can be employed to generate group constants in an application- dependent multigroup structure. An application-independent multigroup data set is one type of averaged data set.
4 Relation to other standards
The following American National Standards are related to this document:
— Nuclear Data Sets for Reactor Design Calculations, ANSI/ANS-19.1-2002 (R2011) [1] , defines the criteria to be employed in the preparation of application-independent cross-section data files from experimental data and theoretical models. This document covers subsequent space and energy averaging processes which may be employed to prepare cross-sections for use in the representation of the core and its environment, and the subsequent calculation of the spatial distribution of neutron reaction rates in the core and of the core reactivity. There may be many ways of carrying out the space and energy averaging to obtain few-group cross-sections, and no unique path for the preparation or use of cross-sections employed in design calculations is defined, required, or recommended by this standard.
— Guide for Acquisition and Documentation of Reference Power Reactor Physics Measurements for Nuclear Analysis Verification, ANSI/ANS-19.4−2017 [3] ; and Requirements for Reference Reactor Physics Measurements, ANSI/ANS 19.5-1995; W2005 [4] .