TY - JOUR
T1 - Adsorption of volatile polonium species on metals in various gas atmospheres: Part III - Adsorption of volatile polonium on stainless steel 316L
AU - Maugeri, Emilio Andrea
AU - Neuhausen, Jörg
AU - González Prieto, Borja
AU - Aerts, Alexander
AU - Mendonca, Tania Melo
AU - Stora, Thierry
AU - Eichler, Robert
N1 - Score=10
PY - 2018/2/7
Y1 - 2018/2/7
N2 - This article summarizes the results obtained studying the interaction between polonium and stainless steel 316L in different atmospheres by the thermochromatography method. This issue is particularly important in terms of licensing of the MYRRHA prototype ADS reactor, where highly radiotoxic α-emitting polonium isotopes are produced in lead-bismuth eutectic used as both spallation target material and coolant, while stainless steel 316L is going to be the main structural material. The polonium adsorption enthalpy on stainless steel 316L in inert atmosphere was measured as −147±6 kJ mol−1. The findings obtained using reducing atmospheres show that the affinity of polonium for stainless steel 316L increases with the metallic character of the stainless steel surface. The presence of moisture in inert and reducing atmosphere does not significantly influence the polonium adsorption. Oxidizing atmospheres induce the formation of polonium dioxide which has a stronger interaction with the stainless steel 316L, with an adsorption enthalpy of −225±6 kJ mol−1. A prolonged exposure of the stainless steel to strong oxidants, such as pure oxygen, reduces the metallic character of the stainless steel surface and, consequently, its affinity to the polonium oxide. Furthermore, it was found that in all experiments at least 5 ppm of the total polonium present in the starting material were not retained on the stainless steel 316L surface at all.
AB - This article summarizes the results obtained studying the interaction between polonium and stainless steel 316L in different atmospheres by the thermochromatography method. This issue is particularly important in terms of licensing of the MYRRHA prototype ADS reactor, where highly radiotoxic α-emitting polonium isotopes are produced in lead-bismuth eutectic used as both spallation target material and coolant, while stainless steel 316L is going to be the main structural material. The polonium adsorption enthalpy on stainless steel 316L in inert atmosphere was measured as −147±6 kJ mol−1. The findings obtained using reducing atmospheres show that the affinity of polonium for stainless steel 316L increases with the metallic character of the stainless steel surface. The presence of moisture in inert and reducing atmosphere does not significantly influence the polonium adsorption. Oxidizing atmospheres induce the formation of polonium dioxide which has a stronger interaction with the stainless steel 316L, with an adsorption enthalpy of −225±6 kJ mol−1. A prolonged exposure of the stainless steel to strong oxidants, such as pure oxygen, reduces the metallic character of the stainless steel surface and, consequently, its affinity to the polonium oxide. Furthermore, it was found that in all experiments at least 5 ppm of the total polonium present in the starting material were not retained on the stainless steel 316L surface at all.
KW - Polonium
KW - thermochromatography
KW - accelerator driven system (ADS)
KW - MYRRHA
KW - stainless steel 316L
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/34788815
U2 - 10.1515/ract-2017-2807
DO - 10.1515/ract-2017-2807
M3 - Article
SN - 0033-8230
VL - 106
SP - 125
EP - 134
JO - Radiochimica Acta
JF - Radiochimica Acta
IS - 2
ER -