[en] During a high temperature treatment of the radioactive wastes that contain ruthenium, some ruthenium is volatilized and released to the off gas system. The volatilized ruthenium is removed with a scrubber and an adsorber. It was expected that the scrubber was one of the most effective equipments to remove ruthenium and the decontamination factor of the scrubber was studied. The experimental apparatus was simulated as part of an actual perforated plate column scrubber. The non-radioactive ruthenium which simulated the radioactive ruthenium was volatilized and fed into the scrubber. The decontamination factor of the scrubber was determined by the ratio of the ruthenium concentration at the inlet and outlet of the scrubber off gas stream. The results showed that the scrubber removed the volatile ruthenium effectively as expected

[en] Ruthenium is partly volatilized and carried to the gas stream during evaporation and calcination of solution which contains ruthenium. Most of the volatilized ruthenium is removed in the first quencher or scrubber, but a small part of the volatilized ruthenium remains in the off gas stream. When the off gas is scrubbed in the next scrubber, e.g. NO_x scrubber, it is expected to remove the remaining ruthenium. This study is intended to examine the efficiency of the scrubber in the decontamination of the volatilized ruthenium. The experimental apparatus consists of an off gas supply system including a RuO₄ generator, a scrubbing water supply system, a plate column and gas samplers. The column is made of three perforated plates

[en] High Level Liquid Waste (HLLW) is planned to be solidified to glass by vitrification process. HLLW is fed to a Liquid Fed Ceramic Melter (LFCM) with glass former and vitrified in it. In this process, a portion of ruthenium in HLLW releases from the LFCM into the off-gas system. The released ruthenium is removed in the off-gas system and the decontaminated off-gas is released from a stack into atmosphere. In this study, the ruthenium release rate from the pilot scale LFCM was evaluated based on an inactive operational data. In the results of the experiments, the release rate of ruthenium from the LFCM were about 10 % of the feed rate of it and similar to previous works. (author)

[en] Purpose: To determine the clinical feasibility of rapid-sequence phosphorus-31 magnetic resonance spectroscopy (³¹P -MRS) of the heart with cardiac patients using a 5T clinical MR system. Material and Methods: Twenty cardiac patients, i.e. dilated cardiomyopathy (DCM)3 cases, hypertrophic cardiomyopathy (HCM) 3 cases, hypertensive heart diseases (HHD) 3 cases, and aortic regurgitation (AR) case were examined using rapid cardiac ³¹P-MRS. Complete three-dimensional localization was performed using a two-dimensional phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. The rapid-sequence ³¹P-MRS procedure was phase encoded in arrays of 8x8 steps with an average of 4 acquisitions. The total examination time, including proton imaging and shimming, for the rapid cardiac ³¹P-MRS procedure, ranged from 0 to 5 min, depending on the heart rate. Student's t test was used to compare creatine phosphate (PCr)/adenosine triphosphate (ATP) ratios from the cardiac patients with those of the control subjects (n≅13). Results: The myocardial PCr/ATP ratio obtained by rapid ³¹P-MRS was significantly lower (P <0.001) in DCM patients (1.82±0.33, mean±SD), and in patients with global myocardial dysfunction (combined data for 20 patients:.89±0.32) than in normal volunteers (2.96±0.59). These results are similar to previous studies. Conclusion: Rapid-sequence ³¹P-MRS may be a valid diagnostic tool for patients with cardiac disease