Characterization of the PTW 34031 ionization chamber (PMI) at RCNP with high energy neutrons ranging from 100 - 392 MeV

Theis, C.*; Carbonez, P.*; Feldbaumer, E.*; Forkel-Wirth, D.*; Jaegerhofer, L.*; Pangallo, M.*; Perrin, D.*; Urscheler, C.*; Roesler, S.*; Vincke, H.*; et al.

EPJ Web of Conferences, 153, p.08018_1 - 08018_5, 2017/09

https://doi.org/10.1051/epjconf/201715308018

At CERN, gas-filled ionization chambers PTW-34031 (PMI) are commonly used in radiation fields including neutrons, protons and -rays. A response function for each particle is calculated by the radiation transport code FLUKA. To validate a response function to high energy neutrons, benchmark experiments with quasi mono-energetic neutrons have been carried out at RCNP, Osaka University. For neutron irradiation with energies below 200 MeV, very good agreement was found comparing the FLUKA simulations and the measurements. In addition it was found that at proton energies of 250 and 392 MeV, results calculated with neutron sources underestimate the experimental data due to a non-negligible gamma component originating from the target Li(p,n)Be reaction.

Heat treatment of phosphate-modified cementitious matrices for safe storage of secondary radioactive aqueous wastes in Fukushima Daiichi Nuclear Power Plant

Irisawa, Keita; Taniguchi, Takumi; Namiki, Masahiro; Garca-Lodeiro, I.*; Osugi, Takeshi; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro; Kinoshita, Hajime*

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 6 Pages, 2017/04

A solidification technique with minimized water content is being developed using phosphate cements for the safe storage of secondary radioactive wastes in the Fukushima Daiichi Nuclear Power Plant. Conventional cement systems become solidified via hydration reactions, and need a certain water content. Phosphate cement systems, however, become solidified via an acid-base reaction, and so they only require water mainly for reasons of workability. A reduced water content of phosphate cement systems is beneficial for the immobilization of the radioactive wastes from mitigating the potential to generate hydrogen gas by the radiolysis of water by radioactive wastes. The current study investigated the water content and mineralogy of calcium aluminate cement (CAC) and phosphate-modified CAC (CAP) cured in open systems at 60, 90 and 120 C and in a closed system at 20 C as a reference case. Water contents in both the CAC and the CAP were seen to decrease as curing progressed. For 90 C, the CAP contained less water than CAC. Free water in CAC converted to structural water by heat treatment, but this was not the case for CAP. An orthophosphate hydrate salt, a precursor phase of hydroxyapatite, was found in CAP when cured at 20 and 60 C, and a mixture of the orthophosphate hydrate salt and hydroxyapatite, Ca(PO)(OH), were formed in the CAP when cured at 90 C. Phosphate products in CAP cured at 120 C appears to consist of a different phosphate phase compared with the CAP cured at 20, 60 and 90 C.

Thick target neutron yield at 0 degree by 250 and 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

Proceedings of 8th Specialists' Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-8), p.195 - 203, 2010/03

Neutron energy spectra at 0 degree produced from stopping-length thick graphite, aluminum, iron and lead targets bombarded by 250 MeV and 350 MeV protons were measured at the neutron TOF course at RCNP of Osaka University. The neutron energy spectra were obtained by using the time-of-flight technique in the energy range from 10 MeV to incident proton energy. To compare the experimental results, Monte Carlo calculations by the PHITS and MCNPX codes using the JENDL-HE and the LA150 evaluated nuclear data files were performed. It was found that these calculated results at 0-degree generally underestimated the experimental results for all targets in the energy range above 20 MeV.

Development of a quasi-monoenergetic neutron field using the Li(p,n)Be reaction in the energy range from 250 to 390 MeV at RCNP

Taniguchi, Shingo*; Nakao, Noriaki*; Nakamura, Takashi*; Yashima, Hiroshi*; Iwamoto, Yosuke; Satoh, Daiki; Nakane, Yoshihiro; Nakashima, Hiroshi; Itoga, Toshio*; Tamii, Atsushi*; et al.

Radiation Protection Dosimetry, 126(1-4), p.23 - 27, 2007/08

https://doi.org/10.1093/rpd/ncm007

A quasi-monoenergetic neutron field was developed using the reaction in the energy range from 250 to 390 MeV in the ring cyclotron facility at the Research Center for Nuclear Physics (RCNP), Osaka University. Neutrons were generated from a 10-mm thick Li target injected by 250, 350 and 392 MeV protons. The neutrons produced at 0 degree were extracted into the 100-m long TOF room through a 150-cm thick ironcollimator of 10 cm 12 cm aperture, and were measured by a 12.7-cm diam. 12.7-cm long NE213 organic liquid scintillator. This neutron field is very useful since experimental data for high energy neutrons in this energy region are very scarce. It has already been used for a neutron shielding experiment.

Measurement of neutron spectra produced in the forward direction from thick graphite, Al, Fe and Pb targets bombarded by 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 562(2), p.789 - 792, 2006/06

https://doi.org/10.1016/j.nima.2006.02.056

Neutron energy spectra produced from thick targets play an important role in validation of calculation codes that are employed in the design of spallation neutron sources and the shielding design of accelerator facilities. However, appropriate experimental data were scarce in the forward direction for the incident energy higher than 100 MeV. In this study, neutron spectra at 0 degree from thick targets bombarded with 350 MeV protons were measured by the time-of-flight technique using an NE213. The targets used were graphite, Al, Fe and Pb and their thicknesses were chosen to be a little thicker than the stopping lengths. The experiment was carried out at the TOF course of the RCNP (Research Center of Nuclear Physics) ring cyclotron, Osaka University. The flight path length between center of the target and of an NE213 were 11.4 m for the measurement of low energy neutrons and 95 m for high energy neutrons. The experimental data are compared with the calculated results by using the Monte Carlo transport codes, such as MCNPX and PHITS codes.

Thick target neutron yield at 0 degree by 250 and 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

no journal, , 

Neutron energy spectra at 0 degree produced from stopping-length thick graphite, aluminum, iron and lead targets bombarded by 250 MeV and 350 MeV protons were measured at the neutron TOF course at RCNP of Osaka University. The neutron energy spectra were obtained by using the time-of-flight technique in the energy range from 10 MeV to incident proton energy. To compare the experimental data, Monte Carlo calculations by PHITS and MCNPX codes using the JENDL-HE and the LA150 evaluated files were performed. It was found that these calculation results at 0-degree generally underestimated the experimental data for all targets in the energy range above 20 MeV.

Development of seismic assessment method toward the demonstration reactor of JSFR, 2; Analysis of vibration test of 1/2.5 scale test assembly in triangular arrangement

Monde, Masatsugu*; Iwasaki, Akihisa*; Sawa, Naoki*; Ikarimoto, Iwao*; Taniguchi, Yoshihiro*; Kitamura, Seiji

no journal, , 

The three-dimensional analysis method of a reactor core is developed. The outline of the analysis method and the applicability of the method by comparison with a vibration test of 1/2.5 scale test assembly are reported.

Development of under sodium viewer, 1; Development requirement

Aizawa, Kosuke; Chikazawa, Yoshitaka; Ara, Kuniaki; Taniguchi, Yoshihiro*; Yui, Masahiro*

no journal, , 

Inspection technique in opaque liquid metal coolant is one of the important issues for safety warranty of Liquid Metal Fast Breeder Reactor (LMFBR) core. To facilitate operations and maintenance activities, an under sodium viewer (USV) has been developed in several research institutes and countries. In this study, the requirement of USV for the 750 MWe sodium fast breeder reactor was made clear on the basis of the reactor structure and the policy for the maintenance and repair. In addition, the sophistication of element technology for the USV was conducted.

Development of solidification techniques with minimised water content for secondary radioactive aqueous wastes in Fukushima, 1; Synthesis and evaluation of simulated wastes

Taniguchi, Takumi; Irisawa, Keita; Ito, Yuzuru; Namiki, Masahiro; Osugi, Takeshi; Abe, Tomohisa; Sato, Junya; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro; et al.

no journal, , 

no abstracts in English

A Micro pixel chamber based neutron imaging detector ( NID) with boron converter for energy-resolved neutron imaging at J-PARC

Parker, J. D.*; Shinohara, Takenao; Harada, Masahide; Hayashida, Hirotoshi*; Hiroi, Kosuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Oikawa, Kenichi; Segawa, Mariko; Su, Y.; et al.

no journal, ,