Effect of the Temperature Change of Material Test Reactor on Calibration of Cluster Dynamics for Neutron Irradiation Pure Iron

Authors O.R. Gokhman, М.S. Kondria

South Ukrainian National Pedagogical University, 26, Staroportofrankivska St., 65020 Odesa, Ukraine

Issue Volume 11, Year 2019, Number 4
Dates Received 03 June 2019; revised manuscript received 07 August 2019; published online 22 August 2019
Citation O.R. Gokhman, М.S. Kondria, J. Nano- Electron. Phys. 11 No 4, 04025 (2019)
DOI https://doi.org/10.21272/jnep.11(4).04025
PACS Number(s) 61.80.Hg, 61.80.Az, 61.72.Ji, 61.82.Bg
Keywords Cluster dynamics, Pure iron, Change of temperature, Vacancy clusters, Self-interstitial clusters.

Cluster dynamics (CD) simulation is used to study the effect of the temperature T change of reactor pressure vessel (RPV) on the evolution of vacancy clusters (VC) and self-interstitial atom clusters (SIAC) in neutron irradiation pure iron in material test reactor (MTR) BR-2 (Mol, Belgium). During operation time of BR-2, T increases from 300 K to 573 K in the first 19 hours, does not change in the next 370 hours and decreases then to 373 K in the last 7 hours. The time evolution of concentrations of single vacancies, C1v, single self-interstitial atoms, C1i, of VC, Cnv, and SIAC, Cni, in pure iron under neutron irradiation in the MTR BR-2 for neutron flux of 1.39 ( 10 – 7 dpa/s in the range fluence from 0.026 to 0.19 dpa are determined by CD simulation for approach on the constant T as well as with taking into account T change of RPV. Then the dose dependences of number density and mean size of SIAC are calculated. The new calibration of defect structure model has been performed from the comparison of experimental transmission electron microscopy (TEM) data and CD simulation results. It was found the migration energy of a vacancy in iron which provides the best coincidence of experimental data and CD results. The difference between predictions of CD model on dose dependences of the number density and mean size with the constant temperature and model with taking into account the change temperature at the beginning and at the end of operation time of MTR BR-2 has been analyzed.

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