Resurgence of a Nation’s Radiation Science Driven by Its Nuclear Industry Needs

From MDPI via Jisc Publications RouterHistory: accepted 2021-10-26, pub-electronic 2021-11-23Publication status: PublishedThis article describes the radiation facilities and associated sample preparation, management, and analysis equipment currently in place at the Dalton Cumbrian Facility, a facility which opened in 2011 to support the UK’s nuclear industry. Examples of measurements performed using these facilities are presented to illustrate their versatility and the breadth of research they make possible. Results are presented from research which furthers our understanding of radiation damage to polymeric materials, radiolytic yield of gaseous products in situations relevant to nuclear materials, radiation chemistry in light water reactor cooling systems, material chemistry relevant to immobilization of nuclear waste, and radiation-induced corrosion of fuel cladding elements. Applications of radiation chemistry relevant to health care are also described. Research concerning the mechanisms of radioprotection by dietary carotenoids is reported. An ongoing open-labware project to develop a suite of modular sample handling components suited to radiation research is described, as is the development of a new neutron source able to provide directional beams of neutrons

TEM micrographs and EELS images of neutron, proton and self-ion irradiated Fe9Cr

This data provides a comparison of the microstructure of a model Fe9Cr alloy subject to irradiation by neutrons, protons or self-ions. The micrographs contained are sufficient to calculate dislocation number densities, sizes, and nature; void number densities and sizes; and the chemical mapping obtained for analysis of chromium redistribution within the alloy

Microstructural examination of neutron, proton and self-ion irradiation damage in a model Fe9Cr alloy

Transmission electron microscopy (TEM) was used to compare the microstructural defects produced in an Fe9Cr model alloy during exposure to neutrons, protons, or self-ions. Samples from the same model alloy were irradiated using fission-neutrons, 2 MeV Fe + ions or 1.2 MeV protons at similar temperatures (∼300 °C) and similar doses (∼2.0dpa). The neutron-irradiated alloy contained visible interstitial dislocation loops with b = 111, and on average ∼5 nm in size. The density varied from 2±1 × 1020 m-3 (in the matrix far from dislocations and boundaries) to 1.2 ± 0.3 × 1023 m-3 (close to helical dislocation lines). Chromium α′-phase precipitates were also identified at a density of 7.4 ± 0.4 × 1023 m-3. Self-ion irradiation produced mostly homogeneously distributed dislocation loops (6–7 nm on average), and with a greater fraction of 100 loops (∼40%) than was seen in the neutron-irradiated alloy, and at a density of 6.8 ± 0.8 x1022 m-3. In contrast to the loops produced by neutron irradiation, the self-ion irradiated Fe9Cr contained only vacancy-type loops. Chromium also remained in solution. Proton-irradiated Fe9Cr contained interstitial dislocation loops close to helical-dislocation segments, similar to the neutron-irradiated sample. Chromium α′-phases were also identified in the proton-irradiated sample at a density of 2.5 ± 0.3 × 1023 m-3, and large voids (up to 7 nm) were found at a density over 1022m−3. Like the neutron-irradiated sample, the density of dislocation loops was also heterogeneously distributed; far from grain boundaries and dislocation lines the density was 2.5 ± 0.4 x1022 m-3, while close to helical dislocation lines the density was 8.1 ± 1.3 x1022 m-3

Microstructural examination of neutron, proton and self-ion irradiation damage in a model Fe9Cr alloy

Transmission electron microscopy (TEM) was used to compare the microstructural defects produced in an Fe9Cr model alloy during exposure to neutrons, protons, or self-ions. Samples from the same model alloy were irradiated using fission-neutrons, 2&nbsp;MeV Fe&nbsp;+&nbsp;ions or 1.2&nbsp;MeV protons at similar temperatures (&sim;300&nbsp;&deg;C) and similar doses (&sim;2.0dpa). The neutron-irradiated alloy contained visible interstitial dislocation loops with&nbsp;b = 111, and on average &sim;5 nm in size. The density varied from 2&plusmn;1 &times; 1020 m-3&nbsp;(in the matrix far from dislocations and boundaries) to 1.2 &plusmn; 0.3 &times; 1023 m-3&nbsp;(close to helical dislocation lines). Chromium &alpha;&prime;-phase precipitates were also identified at a density of 7.4 &plusmn; 0.4 &times; 1023 m-3. Self-ion irradiation produced mostly homogeneously distributed dislocation loops (6&ndash;7 nm on average), and with a greater fraction of&nbsp;100&nbsp;loops (&sim;40%) than was seen in the neutron-irradiated alloy, and at a density of 6.8 &plusmn; 0.8 x1022 m-3. In contrast to the loops produced by neutron irradiation, the self-ion irradiated Fe9Cr contained only vacancy-type loops. Chromium also remained in solution. Proton-irradiated Fe9Cr contained interstitial dislocation loops close to helical-dislocation segments, similar to the neutron-irradiated sample. Chromium &alpha;&prime;-phases were also identified in the proton-irradiated sample at a density of 2.5 &plusmn; 0.3 &times; 1023 m-3, and large voids (up to 7 nm) were found at a density over 1022m&minus;3. Like the neutron-irradiated sample, the density of dislocation loops was also heterogeneously distributed; far from grain boundaries and dislocation lines the density was 2.5 &plusmn; 0.4 x1022 m-3, while close to helical dislocation lines the density was 8.1 &plusmn; 1.3 x1022 m-3.</p