Nuclear energy - Determination of neutron fluence and displacement per atom (dpa) in reactor vessel and internals
Abstract
ISO 19226:2017 provides a procedure for the evaluation of irradiation data in the region between the reactor core and the inside surface of the containment vessel, through the pressure vessel and the reactor cavity, between the ends of active fuel assemblies, given the neutron source in the core. NOTE These irradiation data could be neutron fluence or displacements per atom (dpa), and Helium production. The evaluation employs both neutron flux computations and measurement data from in-vessel and cavity dosimetry, as appropriate. This document applies to pressurized water reactors (PWRs), boiling water reactors (BWRs), and pressurized heavy water reactors (PHWRs). ISO 19226:2017 also provides a procedure for evaluating neutron damage properties at the reactor pressure vessel and internal components of PWRs, BWRs, and PHWRs. Damage properties are focused on atomic displacement damage caused by direct displacements of atoms due to collisions with neutrons and indirect damage caused by gas production, both of which are strongly dependent on the neutron energy spectrum. Therefore, for a given neutron fluence and neutron energy spectrum, calculations of the total accumulated number of atomic displacements are important data to be used for reactor life management.
Begin
2023-05-12
WI
00430115
Planned document number
DIN EN ISO 19226 rev
Project number
06236536
Responsible national committee
NA 062-07-54 AA - Criticality safety and decay power
Responsible european committee
CEN/TC 430 - Nuclear energy, nuclear technologies, and radiological protection
Responsible international committee
ISO/TC 85/SC 6/WG 1 - Power reactor analyses and measurements
