On 11th May, Dr. Joseph gave a presentation on behalf of Dr. Wren at the The University Network of Excellence in Nuclear Engineering (UNENE) Research Advisory Committee Meeting #42, at the University of Guelph. The talk was entitled "Radiolysis-induced Corrosion of Dissimilar Metal Welds".
Dr. Jiju Joseph (far left) presented a talk on behalf of Dr. Wren at the 2018 Information Exchange Meeting on Super-Critical-Water-Cooled Reactors hosted by the Canadian Nuclear Society. The talk was entitled “Effects of Radiolysis on Materials Degradation under Sub‐ and Supercritical Water Conditions: Experimental and Modelling Studies”. The meeting was held in Montreal.
The Nuclear Waste Management Organization (NWMO) is one of our industrial partners and is collaborating with us on several projects involving the corrosion of metals under radiation. On 3rd May, NWMO scientists Dr. Mehran Behazin and Dr. Peter Keech visited us so that we could update them on our research progress and consult on our laboratory protocols. Graduate students Dan Guo, Jennifer Shin, Masoumeh Naghizadeh and Lindsay Grandy gave presentations on the progress of their research projects. Some great insights and suggestions came out of these discussions!
Rose Karimihaghighi, a PhD candidate in the Wren Group, has just been awarded an OGS scholarship. Congratulations, Rose!
Rose's research involves studying the effect of pH, temperature, ionic strength, and γ-radiation on corrosion and oxide formation on pure (> 99.95%) nickel and Alloy 600. These materials are widely used in the nuclear industry due to their tendency to form corrosion-resistant oxide films. They are exposed to gamma-radiation and radiolysis products in the coolant flowing from the reactor core. In order to improve the fundamental understanding of the corrosion of these alloys, the kinetics of metal oxidation and oxide formation are being studied by performing various experiments.
Ontario Power Generation (OPG) is one of our industrial partners and is collaborating with us on two related projects. The first involves using a high-powered laser to clean oxides from metal surfaces, and the second the use of geopolymers to encapsulate ion exchange resins for disposal. Some OPG scientists and engineers visited us here at Western so that we could update them on our research progress. In the above images, graduate students Thao Do and Ryan Morco give presentations on their research progress and show the laser set-up and some geopolymers that have been produced. A technician from Laserax, a company in Quebec that manufactures the laser we are using, also came to help demonstrate the laser.
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!