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Ho, H. Q.; Ishitsuka, Etsuo
Physical Sciences and Technology, 5(2), p.53 - 56, 2019/00
Increasing of tritium concentration in the primary coolant of the research and test reactors during operation had been reported. To check the source for tritium release into the primary coolant during operation of the JMTR and the JRR-3M, the tritium release from the driver fuels was calculated by MCNP6 and PHITS. It is clear that the calculated values of tritium release from fuels are as about 10
and 10
Bq for the JMTR and JRR-3M, respectively, and that calculated values are about 4 order of magnitude smaller than that of the measured values. These results show that the tritium release from fuels is negligible for both the reactors.
Ishitsuka, Etsuo; Kenzhina, I. E.*
Physical Sciences and Technology, 4(1), p.27 - 33, 2018/06
Increase of tritium concentration in the primary coolant for the research and testing reactors during reactor operation had been reported. To clarify the tritium sources, a curve of the tritium release rate into the primary coolant for the JMTR and the JRR-3M are evaluated. It is also observed that the amount of released tritium is lower in the case of new beryllium components installation, and increases with the reactor operating cycle. These results show the beryllium components in core strongly affect to the tritium release into the primary coolant. As a result, the tritium release rate is related with produced Li by (n,
) reaction from 
Be, and evaluation results of tritium release curve are shown as the dominant source of tritium release into the primary coolant for the JMTR and the JRR-3M are beryllium components. Scattering of the tritium release rate with irradiation time were observed, and this phenomena in the JMTR occurred in earlier time than that of the JRR-3M.
Ishitsuka, Etsuo; Kenzhina, I. E.*; Okumura, Keisuke; Takemoto, Noriyuki; Chikhray, Y.*
JAEA-Technology 2016-022, 35 Pages, 2016/10
JAEA-Technology-2016-022.pdf:3.73MB
As a part of study on the mechanism of tritium release to the primary coolant in research and testing reactors, the calculation methods by PHITS code is studied to evaluate the recoil tritium release rate from beryllium core components. Calculations using neutron and triton sources were compared, and it is clear that the tritium release rates in both cases show similar values. However, the calculation speed for the triton source cases is two orders faster than that for the neutron source case. It is also clear that the calculation up to history number per unit volume of 2
10
(cm
) is necessary to determine the recoil tritium release rate of two effective digits precision. Furthermore, the relationship between the beryllium shape and recoil tritium release rate using the triton sources was studied. Recoil tritium release rate showed linear relation to the surface area per volume of beryllium, and the recoil tritium release rate showed about half of the conventional equation value.
Atarashi-Andoh, Mariko; Amano, Hikaru; Ichimasa, Michiko*; Ichimasa, Yusuke*
Fusion Science and Technology, 41(3), p.427 - 431, 2002/05
In processes of tritium transfer in the environment, conversion of HTO to OBT in plant by photosynthesis is important for both aspects of monitoring and dose estimation. Because once OBT is formed in plant, it stays in the plant for longer time than HTO, and OBT is more harmful than HTO for human body. Conversion rate of HTO in plant leaf to OBT in plant edible parts in the open air were obtained for some plants (komatsuna, radish and cherry tomato) during the chronic HT release experiment at Chalk River in 1994. At the experiment, HT gas was released to the atmosphere at the cultivated site for 12 days continuously [1]. HTO and OBT concentration in cultivated plants were measured during the experiment. For plant leaves conversion rate of HTO to OBT was about 0.2 (% h
) but it varied with their growth stage. A chamber experiment in laboratory was also carried out for comparison.
-LiAlO
;
Journal of Nuclear Materials, 138, p.210 - 214, 1986/00
Times Cited Count：33 Percentile：93.33(Materials Science, Multidisciplinary)no abstracts in English
N; ;
Journal of Nuclear Materials, 116, p.78 - 81, 1983/00
Times Cited Count：8 Percentile：68.35(Materials Science, Multidisciplinary)no abstracts in English
;
Radioisotopes, 29(10), p.484 - 489, 1980/00
no abstracts in English
