Standard Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance

Importancia y uso:

5.1 Radiometric monitors shall provide a proven passive dosimetry technique for the determination of neutron fluence rate (flux density), fluence, and spectrum in a diverse variety of neutron fields. These data are required to evaluate and estimate probable long-term radiation-induced damage to nuclear reactor structural materials such as the steel used in reactor pressure vessels and their support structures.

5.2 A number of radiometric monitors, their corresponding neutron activation reactions, and radioactive reaction products and some of the pertinent nuclear parameters of these RMs and products are listed in Table 1. Table 2 provides data (37) on the cumulative and independent fission yields of the important fission monitors. Not included in these tables are contributions to the yields from photo-fission, which can be especially significant for non-fissile nuclides (2-5, 27-29, 38-41).

(A) All yield data are given as a percentage with associated uncertainties given as percentages of the percentage at the 1σ level.(B) For this fission yield evaluation (37), “Fast” indicates that the data was extracted from a wide range of reactor-based fission neutron spectra that can be characterized as having an average energy of ~0.4 MeV. Almost all of the fission reactions for U-238 and Th-232 occur above an effective threshold energy of ~1 MeV and, for Np-237, above ~0.2 MeV.

Subcomité:

E10.05

Referida por:

E0844-18, E0393-19, E0266-23, E0263-18, E1297-18, E1006-21, E1035-18R23, E0523-21E01, E0526-22, E0853-23, E0704-19, E1018-20E01, E0705-18, E0261-16R21, E2956-23, E2059-20, E0910-24, E0264-19, E0944-19, E0900-21, E0706-23

Volúmen:

12.02

Número ICS:

17.240 (Radiation measurements)

Palabras clave:

activity; fission monitor; monitor foil; neutron fluence; pressure vessel; radiometric monitor; reaction rate; reactor surveillance;