Preliminary investigation of pretreatment methods for liquid scintillation measurements of environmental water samples using ion exchange resins

Nakasone, Shunya*; Yokoyama, Sumi*; Takahashi, Tomoyuki*; Ota, Masakazu; Kakiuchi, Hideki*; Sugihara, Shinji*; Hirao, Shigekazu*; Momoshima, Noriyuki*; Tamari, Toshiya*; Shima, Nagayoshi*; et al.

Plasma and Fusion Research (Internet), 15, p.2405027_1 - 2405027_3, 2020/05

https://doi.org/10.1585/pfr.15.2405027

A quick preprocessing system for tritium analysis of environmental samples is important to judge environmental influence of tritium releases due to accident or tritium-handling facilities. Analysis of tritium in water samples with liquid scintillation counting method requires removal of impurities such as organic matter and ion species from water samples. Generally, a distillation method is adopted as a pretreatment of analysis for tritium; however, the distillation method is a time-consuming process. The aim of this study is to evaluate a rapid pretreatment method for tritium analysis with ion exchange resin. From batch and column experiments that used inland water and ion exchange resin, we confirmed removals of impurities of the water sample and that the removal of impurities was possible for a short time (by 5 minutes).

Formation and retention of organically bound deuterium in rice in deuterium water release experiment

Atarashi-Andoh, Mariko; Amano, Hikaru; Kakiuchi, Hideki; Ichimasa, Michiko*; Ichimasa, Yusuke*

Health Physics, 82(6), p.863 - 868, 2002/06

https://doi.org/10.1097/00004032-200206000-00015

As a substitute of tritium, deuterium water (D2O) vapor release experiments were performed to estimate the difference of formation and subsequent retention of organically bound deuterium (OBD) in rice plants between daytime and nighttime exposure. Potted plants were exposed to deuterium water vapor in a greenhouse for 8 hours, under day and night conditions. Deuterium concentrations in free water and organic matter in rice leaves and ears were investigated until the harvest time. Data analysis was carried out using a model in which different generating processes of organic matter were considered. The calculated results agreed with the measured value.

Research and considerations of radiation control in decommissioning

Goda, Tadashi; Ando, Hideki

JNC TN9420 2000-001, 54 Pages, 1999/09

JNC-TN9420-2000-001.pdf:2.8MB

In O-arai Engineering Center of Japan Nuclear Cycle Development Institute, dccommissioning of nuclear facilities will be expected in future. The results of preceding JPDR decommissioning were researched and the radiation control in decommisioning was examined. The principles and technology necessaly for radiation control in decommissioning were arranged. The radiation control in decommissioning seems to be on extension line of daily radiological work control. Noticing points all the control of exposure dose with disassembly of high radiological equipment, the surface contamination measurement of building disassembly waste which large arises and the radioactivity measurement of activated material. When high radiological equipment is disassembled, the measures which reduce the exposure in the remote manipulation are taken. The total adiation protection program including the control of exposure dose in preparedness stage must be decided. Much time and personnel are required, when surface contamination of waste arisen in the building disassembly was measured by surveymeters. Therefore, it is necessaly to rationalize the measurement using automatic inspection equipment with large detection area. This type equipment has results which effectively fulfilled the function in the decommissioning of JPDR. It is possible to product the equipment in the combination of existing technology.

Report of radiation exposure control on the 11th periodic inspection at experimental fast reactor JOYO; Reported by radiation control section

; ; ; Ando, Hideki

PNC TN9410 97-094, 27 Pages, 1997/10

PNC-TN9410-97-094.pdf:0.85MB

The 11th periodic inspection had been executed at the experimental fast reactor JOYO from May 10,1995 to March 24,1997. Because the inspection had been extended several times, the time span of external exposure control was divided into two period. The result of collective dose equivalent in the previous term(from May 10,1995 to December 7,1996: about seventeen months) was 243.34 man*mSv, whereas, the expected collective dose equivalent was about 280man*mSv. The result of collective dose equivalent in the latter term (from December 8,1996 to March 24,1997: about three months) was 44.73 man*mSv, whereas, the expected collective dose equivalent was about 85man*mSv. The collective dose equivalent in the whole period of this inspection was 288.07 man*mSv. It was confirmed that this inspection was carried out with the suitable radiation protection programmes. In this report, the method for the control of external exposure and the reduction of external exposure, provided in 11th periodic inspection, were described with taking the results of the past periodic inspections into consideration.

Development of a radioactive gas monitor using plastic scintillation fibers

Nozaki, Tatsuo; Torii, Tatsuo; Takada, Chie; Tobita, Kazunori; Ando, Hideki

PNC TN9410 96-262, 96 Pages, 1996/09

PNC-TN9410-96-262.pdf:3.27MB

The basic research on large electron linear accelerator is under current investigation at Quantum Technology Development Facility in O-arai Engineering Center, Power Reactor and Nuclear Fuel Development Corporation. The result of this, the transmutation of fission products would be incorporated In the future demonstrative stage of the transmission of fission products, Nitrogen-13 and Oxygen-15 will be produced by the interaction between high energy bremsstrahlung and air during operation of the linac. The detection limits of conventional monitors are not sufficient for the limits of the concentration of Nitrogen-13 (610 Bq/cm) and Oxygen-15 (610 Bq/cm) in exhaust air. Therefore we have developed a new type of gas monitor detector that is packed with plastic scintillation fibers as the detection elements to detect the limits of concentration of Nitrogen-13 and Oxygen-15 in exhaust air. On designing the gas monitor detectors, the sensitivities of the detectors were simulated to optimize the shape and the volume of detector by using EGS4, the Monte-Carlo code for electrons and photons. Based on the results of the simulations, the detectors were composed and the characteristic examinations of sensitivities were carried out by using beta-ray checking sources and Krypton-85 gas. Main points are as follows : (1) The detection limit of the developed torus-type detector for Krypton-85 is 5.410 Bq/cm based on the results of the experiments. (2) The counting efficiency of a detector for Nitrogen-13 is 40 percent higher than the counting efficiency for Krypton-85 based on the results of simulations. This indicates that the detection limit of the detector for Nitrogen-13 is about 3.9 10 Bq/cm. (3) The beta-ray energy of Oxygen-15 is higher than the beta-ray energy of Nitrogen-13. This theoretically reaches the conclusion that the detection limit of the detector for Oxygen-15 is lower than the ...

Realistic contamination control methods at and () nuclide coexistence facilities

Ando, Hideki;

PNC TN9100 96-007, 32 Pages, 1996/03

PNC-TN9100-96-007.pdf:1.09MB

At the light water reactors with no fuel failure, radioactive contamination control is needed for () nuclides such as Co and Mn. On the other hand, at the nuclear facilities where irradiated fuels (spent fuels) are handred, contamination control is needed for many kinds of and () nuclides. There are three facilities where destructive testing of irradiated fuels and materials is done at Oarai Engineering Center. The ratios of the nuclidc composition are considerably stable at these facilities. Therefore, daily contamination control is cxecuted by measuring total (gross) () activity with paying attention to the representative nuclides such as Pu, Pu and Sr. The investigation about the ratios of the nuclide composition, the basic idea of the contamination control, and the reality of the contamination control in the facilities are reported.

Development of compound neutron dose meter

Hashimoto, Makoto; Torii, Tatsuo; Ando, Hideki

PNC TN9410 95-189, 69 Pages, 1995/08

PNC-TN9410-95-189.pdf:2.88MB

The new radiation weighting factors for neutron are introduced in ICRP 1990 Recommendations instead of the former quality factor. The contribution of intermediate energy neutron to the dose estimated with the new factors is more serious than with the former factors. Therefore, it indicates that the neutron dose evaluated by the former factors sometimes underestimates the dose evaluated by the new factors. Accordingly, to develop the neutron dose meter adjusted to the new recommendations, the new neutron detector has been cxperimented. In this study, instead of moderated detectors usually used as a neutron dose rate meter, the compound detector based on the multidetector method was employed. To understand the characteristic of this detector, we simulated the energy response and carried out the characteristic cxamination with neutron sources and accelerators. As a result of energy response simulation, in the region of interest, it can apply the multidetector method. As a result of characteristic examination, the detector can be used for measuring the neutron dose. Furthermore, in processes of the examination, this detector can discriminate the average energy of neutrons of Am-Be from that of Pu-Be. It is very sensitive to the neutron cnergy difference at intermediate energy. In future, it will be made improvement to make more practical dose estimation, and it will be made investigation to apply the ability of energy resolution.

Research and tests of position sensitive radiation detector

Emoto, Takehiko; ; Ando, Hideki

PNC TN9410 93-186, 65 Pages, 1993/09

PNC-TN9410-93-186.pdf:2.24MB

From the viewpoint of radiation protection and radiation shielding evaluation, the needs to know the positions that are irradiated by radiation are increasing, because measuring irradiated positions is useful for detecting local streaming at working areas in nuclear facilities and evaluating beam-loss from accelerators. We have investigated and experimented the characteristics of plastic scintillating fiber(PSF), that has been recently developed one of most popular position sensitive particle detectors in high energy physics, for purpose of that we can apply them to the radiation measurements as a position sensitive radiation detector. First, we referred to the results of the committed research performed in last year and to relative works. And, to aim for improvement of efficiency of gamma-ray and for stretch of the detector, we investigated efficiency and resolution of the detectors giving priorities to (a) variation of length and bundle of PSFs hamess, and (b) variation of the irradiated positions. As the results of referring to the works and the experiments on the detectors, we got the followings, (1)The method using the difference of reaching time between the scintillation photons from both ends of PSF is hopeful as position sensitive radiation detecting, because PSF has good time resolution and the time measurements have been recently developed to be rather easy and accurate methods. (2)Position resolution is 20cm to 30cm for collimated gamma-ray of Cs. And, the detectors bundled of ten PSFs have better characteristics of both efficiency and resolution. (3)When the detector is irradiated at near one of the ends, the efficiency and resolution will be 10% to 30% worse than irradiated at middle of it.

None

Ando, Hideki

Hoken Butsuri, , 

None

Results of heat treatment trial of ITER toroidal field coil

Yamane, Minoru; Matsui, Kunihiro; Kajitani, Hideki; Hemmi, Tsutomu; Takano, Katsutoshi; Ando, Shinji; Koizumi, Norikiyo

no journal, , 

no abstracts in English