With a goal to facilitate removal of trace amounts of radioisotopes dissolved in water, we conducted column chromatographic experiments with an anion-exchanger at high pressures up to 19MPa at 5 and 25°C to recover stable boron isotopes, as a substitute for radioisotopes, from its 0.10mmol L−1 solution. The results showed that the dynamic adsorption capacity, q, increased with increasing pressure and decreasing temperature. The largest q value obtained was 2.33mmol g−1 at 19MPa(5°C), 1.7 times larger than that at the standard temperature and pressure. This indicates that the chromatographic technique to purify waters contaminated by trace amounts of toxic solutes can be improved by controlling pressure and temperature.
To study the uptake of glutamine in a rice seedling, a double-labeled (15N, 13C) glutamine was supplied for an hour and the glutamine in the seedling was analyzed using the high performance liquid chromatography equipped with the ion trap mass spectrometer. The mass spectrum peak of 15N- and 13C-glutamine was detected both in underground and above-ground part of the rice, suggesting that glutamine itself was absorbed from the root without decomposition at rhizosphere and was transferred to the above-ground part.
In the vicinity of intense accumulation of 18F-FDG, 3D acquisition data caused false-negative and false-positive findings. On the other hand, 2D acquisition date showed little or no false-negative findings or false-positive. Combination of 3D and 2D acquisition images seem to be able to compensate mutual drawbacks. In actual clinical practice, whole-body image was taken with 3D acquisition at first, and then sequential 2D acquisition images were added when the metabolically abnormal foci showed intense accumulation of 18F-FDG.
Changes in the radioactivity of 131I, 134Cs and 137Cs in milk which was produced by the cow supplied the pasture (Italian ryegrass) were examined from 30th May(about 2.5 months after the accident in Fukushima Daiichi Nuclear Power Plant) to 26th June, 2011. In Animal Resource Science Center located at Ibaraki-prefecture (about 130km south-west of far from the power plant), the cows were kept and the pasture was cultured. No 131I was detected neither the milk nor the pasture. It was found that the radioactive nuclides (134Cs and 137Cs) included in the pasture, which was given to the cow for 2 weeks, were transferred to the milk. After exchange the feed from the pasture to imported feed, which was given for 2 weeks, radioactivity in the milk rapidly decreased. The radioactivity of these nuclides in the cow milk were lower than the provisional and new confirmed government regulated values(200 and 50Bq/kg for radioactive Cs, respectively).
The Japan Radioisotope Association conducted a questionnaire survey to ascertain status of QA/QC activity of PET in Japan. The questionnaire was sent to 277 PET facilities with 116 valid responses(41.9%). The survey revealed that acceptance test of PET was performed by vender in 86.0% and by facility in 7.6% of the scanners. System sensitivity, accuracy of image registration, image homogeneity, accuracy of dead-time correction and accidental coincidence, and accuracy of attenuation and scatter correction was tested in 59.6%, 57.9%, 55.0%, 29.2%, and 28.1% of the PET scanners, respectively. The count normalization and cross calibration was tested once in 3 months in 71.5% of the scanners. Maintenance service contract was present in 93.3%. Normalization factor, cross calibration factor, and SUV were varied from −11 to +20%, from −8 to +54%, and from −20 to +10% between the initial and the last tests. Dose calibrator and well counter was regularly checked in 55.0% and 82.6% of the equipment, respectively.
High-level radioactive waste (HLW) contains minor actinides (MA) which dominate long-term potential radiological hazard. The transmutation technology is to transform MA to short-lived or stable nuclides by nuclear reactions, and makes it possible to reduce the potential radiological hazard of HLW and the area to dispose of it. The accelerator-driven system (ADS) is recognized as a dedicated tool to transmute MA, and variety of research and development activities for it are under way in the world. The research areas to be covered spread over wide range of scientific and technological fields on an accelerator, a spallation target, materials, nuclear reactor engineering, nuclear fuel, and so on. It is, therefore, of great importance to facilitate international collaboration. The Transmutation Experimental Facility of J-PARC is being proposed as one of possible centers of excellence.