Gamma radiation induces hydrogen absorption by copper in water

One of the most intricate issues of nuclear power is the long-term safety of repositories for radioactive waste. These repositories can have an impact on future generations for a period of time orders of magnitude longer than any known civilization. Several countries have considered copper as an outer corrosion barrier for canisters containing spent nuclear fuel. Among the many processes that must be considered in the safety assessments, radiation induced processes constitute a key-component. Here we show that copper metal immersed in water uptakes considerable amounts of hydrogen when exposed to γ-radiation. Additionally we show that the amount of hydrogen absorbed by copper depends on the total dose of radiation. At a dose of 69 kGy the uptake of hydrogen by metallic copper is 7 orders of magnitude higher than when the absorption is driven by H2(g) at a pressure of 1 atm in a non-irradiated dry system. Moreover, irradiation of copper in water causes corrosion of the metal and the formation of a variety of surface cavities, nanoparticle deposits, and islands of needle-shaped crystals. Hence, radiation enhanced uptake of hydrogen by spent nuclear fuel encapsulating materials should be taken into account in the safety assessments of nuclear waste repositories.Peer reviewe

BioMAX the first macromolecular crystallography beamline at MAX IV Laboratory

BioMAX is the first macromolecular crystallography beamline at the MAX IV Laboratory 3 GeV storage ring, which is the first operational multi bend achromat storage ring. Due to the low emittance storage ring, BioMAX has a parallel, high intensity X ray beam, even when focused down to 20 mm 5 mm using the bendable focusing mirrors. The beam is tunable in the energy range 5 25 keV using the in vacuum undulator and the horizontally deflecting doublecrystal monochromator. BioMAX is equipped with an MD3 diffractometer, an ISARA high capacity sample changer and an EIGER 16M hybrid pixel detector. Data collection at BioMAX is controlled using the newly developed MXCuBE3 graphical user interface, and sample tracking is handled by ISPyB. The computing infrastructure includes data storage and processing both at MAX IV and the Lund University supercomputing center LUNARC. With state of the art instrumentation, a high degree of automation, a user friendly control system interface and remote operation, BioMAX provides an excellent facility for most macromolecular crystallography experiments. Serial crystallography using either a high viscosity extruder injector or the MD3 as a fixedtarget scanner is already implemented. The serial crystallography activities at MAX IV Laboratory will be further developed at the microfocus beamline MicroMAX, when it comes into operation in 2022. MicroMAX will have a 1 mm x 1 mm beam focus and a flux up to 10 15 photons s 1 with main applications in serial crystallography, room temperature structure determinations and time resolved experiment

Interactions Between Different Elements – The Need for Mineral Balance?

Minerals are important for the human body. Mineral ratios are also important since minerals can operate both antagonistically and synergistically with each other. Water with a high concentration of calcium, hard water, reduces the corrosion of copper and lead from pipes. Calcium and magnesium are synergists in the body and cooperate at moderate levels, but an elevated calcium: magnesium ratio in especially mineral–poor water is a threat against heart health. Zink, iron, copper, and molybdenum are examples of elements that are antagonists, and one element can depress the other, while at moderate concentrations e.g. copper is needed for iron utilisation. Mg in drinking water decreases the risk of rectal cancer from THMs. When the ratio between nutrient mineral elements and toxic was high, women were healthier.</p

Corrosion rate of pure copper in an oxic bentonite/saline groundwater environment

The principal strategy for high level radioactive waste disposal in Sweden is to enclose the spent fuel in copper canisters that are embedded in bentonite clay similar to 500 m down in the Swedish bedrock. At this depth, the groundwater is reducing. However, oxic conditions are initially established in the repository during emplacement. The corrosion rate of pure copper in an oxic bentonite/saline groundwater environment has been followed by thin electrical resistance sensors placed in a bentonite test package that was kept at room temperature for 3 years. The corrosion potentials of the sensors have verified oxic conditions in the test package. The corrosion rate of pure copper in this environment has been found to slowly decrease to quite low but measurable values; from above 15 mu m/year down to similar to 1 mu m/year after 3 years of exposure. The measurements have verified a desired behaviour of copper in the environment.</p