The Wren Group visited the Nuclear Waste Management Organization's Proof Test Facility in February, 2018. This was a fantastic opportunity for information exchange between NWMO and its academic research partners from several universities. We got to see the used fuel container, bentonite clay box production, and fabrication and transportation technologies. Dr. Joseph gave a presentation about our group's collaborative research with NWMO. Our students gave poster presentations on their research projects and had many fruitful discussions. Thanks, NWMO, for hosting such a useful and well-organized event!
In November, Dr. Wren attended the Corrosion Prediction and Mitigation for Key Components of Fukushima Daiichi NPS conference in Japan as an invited keynote speaker. Her lecture was entitled "Effects of Chemical and Physical Properties of Solution on Radiolysis Induced Corrosion of Carbon Steel". This is Dr. Wren's second invited visit to Fukushima to provide expertise on radiation-influenced corrosion to assist with the the decontamination and decommissioning process.
2018 commences with the fantastic news that two of our graduate students have been awarded 2018 Roy G. Post Foundation scholarships! This scholarship was established to help students develop careers in the safe management of nuclear materials. Congratulations to Dan Guo and Joseph Turnbull!
Dan's research work involves studying the corrosion behaviour of carbon steel, the material used for the inner vessel of Canada's proposed container for the storage of spent fuel. Although carbon steel corrosion is well studied, prediction of its progression in the storage environment is still difficult. One major reason for this is that the understanding of corrosion processes in the presence of ionizing radiation is limited. Another reason is that the required lifetime of the UFC is around a thousand to a million years. This duration is much longer than any laboratory experiments. Dan is currently performing modeling calculations of the predicted corrosion damage of the interior of the UFC, to determine the effect of different solution properties, such as pH, ionic strength, and O2 concentration on the corrosion process.
Joseph's research also relates to the proposed spent fuel container, but his work involves studying the corrosion of the external copper coating of the container, rather than the carbon steel shell. The overall goal of this wider project is to determine whether gamma radiolysis of water can influence the corrosion of a copper-coated steel nuclear waste container. The proposed use of a thin-walled copper-coated steel container makes it possible that corrosion could be radiolytically supported in the early stages of emplacement in the repository. The influence of radiation is being studied directly and by the addition to the exposure environment of chemical species that mimic the radiolysis products. Joseph's project involves electrochemical studies in small water volumes to study the effect of radiolytically produced nitric acid on the copper corrosion rate.
Just before Christmas we visited OPG's mock-up reactor and got to see many of the reactor components in 1:1 scale and in context. We are grateful to OPG for arranging this visit which has been really beneficial in understanding and visualizing the configurations of some of the components that we are studying in the laboratory.
Our PhD candidate Mojtaba Momeni has successfully defended and become Dr. Momeni! Congratulations, Moji!
Max Fang has been with the group for a year as a visiting graduate student, and during this time has mostly been working on modelling the kinetics of copper corrosion. Max's work has given us new insights into copper corrosion kinetics, allowing us to refine our reaction mechanisms and predictive capabilities. He has also also made great efforts over the last few months to improve the general modelling skills of the group. Thanks for all your hard work! Max, we'll miss you, and we wish you the best of luck in finishing your Phd and whatever you decide to do afterwards.
Congratulations to our PhD candidate Ryan Morco who is the recicipient of a 2017 Roy G. Post Foundation Scholarship. The Roy G. Post Foundation is a non-profit organization that provides scholarships to students to develop careers in the safe management of nuclear materials and to participate in the WM Conference.
Ryan’s research is to assess the influence of gamma-radiation on the proposed used fuel container’s materials, and particularly that of copper corrosion under the different deep geologic repository (DGR) conditions. He is developing a chemical kinetics model on the radiolysis of humid air, pure water and saline groundwater which are conditions anticipated in a nuclear waste DGR environments. These models predict radiolytic oxidants and their concentrations which are then tested for corrosivity and compared with a radiation exposure experiments.
The R.E. Jervis Award is provided by the Canadian Nuclear Society (CNS) and recognizes excellence in research and development carried out by a full time graduate student in nuclear engineering or related fields. It is awarded once a year. Congratulations to our PhD candidate Mojtaba Momeni for winning this prestigious prize.
Mojtaba's research is in the area of corrosion of Cr-Fe-Ni alloys in nuclear reactor environments. His research on enhancing the understanding and modelling of corrosion kinetics and how water chemistry induced by gamma radiation may affect corrosion kinetics has already produced significant outcomes valuable to the Canadian nuclear industry.
More information about the R.E. Jervis Award can be found here:
Belated congratulations to Arielle on the successful defense of her MSc. thesis "Evolution of Cu2O Morphology During Copper Corrosion in the Presence of Gamma-Radiation" Well done! Details on Arielle's thesis can be found here:
Congratulations to our PhD candidate Mi Li for winning the award for the best oral presentation at the NACE southern Ontario student section.
Mi is studying the effect of γ-radiation on the corrosion of carbon steel (CS, SA36) - stainless steel (SS, Type 304L) welds under different pH and temperature conditions. These types of welds are used in CANDU nuclear reactors in regions that are exposed to water under a constant flux of γ-radiation. When exposed to ionizing radiation, water decomposes into some highly redox-active species which might affect the corrosion behaviour of metals. These factors, as well as possible changes in the temperature, can affect the rate of corrosion.