Supercritical water pretreatment method for analysis of strontium and uranium in soil (Andosols)

Nagaoka, Mika; Fujita, Hiroki; Aida, Taku*; Guo, H.*; Smith, R. L. Jr.*

Applied Radiation and Isotopes, 168, p.109465_1 - 109465_6, 2021/02

https://doi.org/10.1016/j.apradiso.2020.109465

The radioactivities in the environmental samples are analyzed to monitor the nuclear power facilities. The pretreatment of radioactive nuclides of alpha and beta emitters in the environmental samples is performed with acid to decompose organic matter and extract object nuclide such as Sr, U and Pu. However, the pretreatment methods are time-consuming and used many concentrated acid solutions that are unsafe and hazardous. Therefore, we develop to the new pretreatment method using supercritical water instead of acid. Hydrothermal pretreatment of soils (Andosols) from Ibaraki prefecture (Japan) was used to improve methods for monitoring radioactive Sr and U. Calcined samples were pretreated with subcritical or supercritical water (SCW) followed by extraction with 0.5 M HNO solutions. With SCW pretreatment, recoveries of Sr and U were 70% and 40%, respectively. Experimental recoveries obtained can be described by a linear relationship in water density. The proposed method is robust and can lower environmental burden of routine analytical protocols.

Key achievements in elementary R&D on water-cooled solid breeder blanket for ITER test blanket module in JAERI

Suzuki, Satoshi; Enoeda, Mikio; Hatano, Toshihisa; Hirose, Takanori; Hayashi, Kimio; Tanigawa, Hisashi; Ochiai, Kentaro; Nishitani, Takeo; Tobita, Kenji; Akiba, Masato

Nuclear Fusion, 46(2), p.285 - 290, 2006/02

https://doi.org/10.1088/0029-5515/46/2/012

This paper presents significant progress in R&D of key technologies on the water-cooled solid breeder blanket for the ITER-TBM in JAERI. By the improvement of heat treatment process for blanket module fabrication, a fine-grained microstructure of F82H, can be obtained by homogenizing it at 1150 C followed by normalizing at 930 C after the HIP process. Moreover, a promising bonding process for a tungsten armor and an F82H structural material was developed by using a uniaxial hot compression without any artificial compliant layer. Also, it has been confirmed that a fatigue lifetime correlation, which was developed for ITER divertor, can be applicable for F82H first wall mock-up. As for R&D on a breeder material, LiTiO, the effect of compression loads on thermal conductivity of pebble beds has been clarified. JAERI have extensively developed key technologies for ITER-TBM, and now steps up into an engineering R&D stage, where integrated performance of TBM structures will be demonstrated by scalable mock-ups.

User's manual of a supporting system for treatment planning in boron neutron capture therapy; JAERI computational dosimetry system

Kumada, Hiroaki; Torii, Yoshiya

JAERI-Data/Code 2002-018, 158 Pages, 2002/09

JAERI-Data-Code-2002-018.pdf:30.28MB

A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimentional head model of a patient by using CT and MRI images and that generates a input data file automaticly for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patinet's head is able to be made easily. The three-dimensional head image is editable to simulate the state of a head after its surgical processes such as skin flap opening and bone removal for the BNCT with craniotomy that are being performed in Japan. JCDS can provide information for the Patient Setting System to set the patient in an actual irradiation position swiftly and accurately. This report describes basic design and procedure of dosimetry, operation manual, data and library structure for JCDS (ver.1.0)

A Preliminary study of CT imaging of water in a carnation flower

Nakanishi, Tomoko*; Furukawa, Jun*; Matsubayashi, Masahito

Nuclear Instruments and Methods in Physics Research A, 424(1), p.136 - 141, 1999/00

https://doi.org/10.1016/S0168-9002(98)01281-9

no abstracts in English

Molecular motion and structure of unsintered polytetrafluoroethylene, 1; Dynamic visco-elastic property

Sasuga, Tsuneo; Takehisa, Masaaki

Reports on Progress in Polymer Physics in Japan, 16, p.343 - 346, 1973/00

no abstracts in English

Rapid removal of cesium from Fukushima contaminated soil by hydrothermal treatment with multivalent cations

Yin, X.; Koma, Yoshikazu; Inaba, Yusuke*; Takeshita, Kenji*

no journal, , 

The decontamination and volume reduction of Cs contaminated soil remains a great challenge after the Fukushima Daiichi Nuclear Power Station accident. In present study, the authors aim to develop the continuous hydrothermal treatment process to remove Cs rapidly from the clay soils by a column system. The results will inspire new insights for treatment of post-accident soils in Fukushima.