Scientific Highlights from Research Division Nuclear Energy and Safety
(NES)
Scientific Highlights
New blueprint for more stable quantum computers
PSI researchers have shown how faster and better defined quantum bits can be created. The central elements are magnetic atoms from the class of so-called rare-earth metals, selectively implanted into the crystal lattice of a material.
Weissbuch Radiochemie Schweiz
In December 2020, the Swiss Academy of Sciences (SCNAT) published its white book on radiochemical education in Switzerland. The report was authored under the lead of Prof. Dr. Roger Alberto (University of Zurich), Dr. Mario Burgener (Spiez Laboratory), and Prof. em. Dr. Heinz W. Gäggeler (University of Bern/Paul Scherrer Institute) and comprises contributions from many experts on the topic from various institutions throughout Switzerland. The white book highlights the imminent loss of experts in the field of radiochemistry and provides solutions to counteract this development.
Radiochemistry at ETH Zurich
As of December 10, 2020, the ETH Zurich appointed PSI’s Prof. Dr. Patrick Steinegger as assistant professor of radiochemistry (tenure track). Thus, the ETH domain took first counter measures against the imminent loss of radiochemical expertise in Switzerland, emphasized in the “Weissbuch Radiochemie Schweiz” by the Swiss Academy of Sciences (SCNAT). Furthermore, the December issue of CHIMIA (Swiss Chemical Society) invited to present the diverse radiochemical activities throughout the country.
CHIMIA: Radiochemistry in Switzerland
The December issue of CHIMIA of the Swiss Chemical Society (SCS) focused on the radiochemical activities throughout Switzerland. Scientists of the Laboratory of Radiochemistry contributed with a number of articles ranging from topics of fundamental sciences to applied research, thereby reflecting on the diverse projects carried out in our laboratory.
New element and speciation specific analytical options at AHL
The Hot Laboratory division (AHL) within PSI’s Nuclear Energy and Safety (NES) division continually upgrades and advances its analytical infrastructure to provide cutting-edge scientific service to PSI’s researchers and industrial customers. A new, fully automatable and highly flexible Ion Chromatograph (IC) furthers AHL’s efforts in sample miniaturization and extends the spectrum of destructive analytical capabilities to element and speciation specific analyses. With the new IC and its modern ICP-MS (Inductively Coupled Plasma Mass Spectrometry) facilities, AHL offers innovative scientific options for nuclear and general research. Moreover, speciation analyses by IC-ICP-MS for polyvalent inorganic water pollutants such as Cr or As and the acquisition of a new ICP-OES system (Inductively Coupled Plasma Optical Emission Spectrometry) enable future autonomy in wastewater management.
Deep geological disposal of radioactive waste in clay rocks
Geological waste disposal, cement clay interaction
• A considerable reduction of HTO and 36Cl− was observed after 6 years interaction.
• The chloride flux showed a much stronger reduction compared to HTO.
• For HTO the relation between the De and the porosity in the clay part can be described using Archie's law.
• No complete clogging of the porosity was observed after 6 years interaction.
Used Nuclear Fuel: from Better Characterization to Better Optimization
A safe, economical and environmental friendly disposal of used nuclear fuel represents an essential objective of relevance for all. This guides the approach under development at the laboratory for reactor physics and thermal-hydraulics. Establish higher resolution simulation methods to gain more detailed knowledge on the content of each single nuclear fuel rod ever irradiated in a reactor. Thereafter, use this knowledge to explore optimization approaches that could potentially enlarge the range of disposal options allowing to fulfill the highest level of safety standards while reducing economical costs and geological footprints at the same time.
Hydrogen uptake into Zr-based fuel claddings
At the hot surface of a fuel rod cladding in the reactor water, the water is partially dissociated in hydrogen and oxygen, leading to corrosion of the cladding and to the uptake of a part of the created hydrogen. Hydrogen in solid solution and in precipitated form changes the mechanical properties of the cladding tube. The uptake of the hydrogen through the dense oxide layer is unclear. The structure and physical properties of the oxide near the metal-interface is critical The resistivity of the oxide increases with distance from the interface. Nb-containing alloys show lower resistivity in the oxide close to the metal interface, and exhibit a lower hydrogen pick-up. The time in the reactor is an important factor, leading to increasing resistivity in the oxide close to the metal interface, and a higher hydrogen uptake late in life.
Relevance of the findings: considering resistivity, the model of hydrogen uptake is better understood, revealing hints for further cladding development.
Life cycle assessment of cars – new web tool helps consumers and researchers
Decision support for car buyers: Researchers at the Paul Scherrer Institute have developed a web tool called the Carculator that can be used to compare the environmental performance of passenger cars in detail.