Community Research and Development Information Service - CORDIS

Abstract

In order to predict the long-lived gamma activities leading to radiation exposure during dismantling operations it is necessary to know the likely trace element content of the reactor vessel and internals. This work has been concerned with measuring the elements Ni, Nb, Mo, Co, Ag, Eu, Sm and Ho in steels, with particular reference to light water reactors. Various steel samples have been provided by organizations in Europe. Analyses have been carried out principally by neutron activation analysis, but also by atomic absorption (AA), inductively coupled plasma (ICP) and secondary ion microprobe spectrometry (SIMS). Analyses for Ni, Mo and Co were straightforward and results agreed with analyses carried out elsewhere. A variety of techniques were employed for Nb; ICP was the most successful and results were confirmed using SIMS.In the case of Ag only flameless AA yielded results for all samples. The low concentration of rare earth elements required the development of a preliminary ion exchange technique. Low-alloy steels examined had Nb concentrations less than 10 ppm. Ag levels in the vicinity of 1 ppm were found in all steel samples, indicating that Ag may be the most significant element at long cooling times. Rare earth concentrations from this and other work indicate that these elements are unlikely to give gamma activities exceeding those of 60-Co, 59-Ni, 108-Ag and 94-Nb activities. Illustrative gamma activity decay calculations using the Origen code are presented.

Additional information

Authors: GODDARD A J H, IMPERIAL COLLEGE, NUCLEAR POWER SECTION, DEPARTMENT OF MECHANICAL ENGINEERING, LONDON (UK);MACMAHON T D, IMPERIAL COLLEGE, NUCLEAR POWER SECTION, DEPARTMENT OF MECHANICAL ENGINEERING, LONDON (UK);GAMBERINI D, IMPERIAL COLLEGE, NUCLEAR POWER SECTION, DEPARTMENT OF MECHANICAL ENGINEERING, LONDON (UK);TAYLOR J M, IMPERIAL COLLEGE, NUCLEAR POWER SECTION, DEPARTMENT OF MECHANICAL ENGINEERING, LONDON (UK);DUGGAN F IMPERIAL COLLEGE, NUCLEAR POWER SECTION, DEPARTMENT OF MECHANICAL ENGINEERING, LONDON (UK), IMPERIAL COLLEGE, NUCLEAR POWER SECTION, DEPARTMENT OF MECHANICAL ENGINEERING, LONDON (UK)
Bibliographic Reference: EUR 9264 EN (1984) FS, 40 P., BFR 200, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989123014600 / Last updated on: 1987-01-01
Category: PUBLICATION
Available languages: en
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top