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Sato, Kazuyuki; Tsubota, Yoichi
no journal, ,
In leaving a radiation controlled area, there sometimes happens alarm of contamination of worker's clothing surface by adhering of natural radionuclides on the surface, could be occurred by static electricity on the clothes surface. For clarifying its mechanism, radon and 
Pb concentration in each room in the controlled area was measured by a radon monitor, and a dust sampler and a Germanium detector, respectively. Moreover, electrostatic charges on each protective clothing were measured by a measuring device of the charge. The study results showed that there may be relationship of the alarm to the natural radionuclides in area and electrostatic charge on protective clothing although more study should be required.
Harada, Masahide; Yamaguchi, Yuji; Hashimoto, Norimichi*; Ito, Taku*; Tajima, Takahiro*; Oku, Takayuki; Haga, Katsuhiro; Ikeda, Hiroshi*; Tamura, Satoshi*
no journal, ,
In Materials and Life Science Experimental Facility at J-PARC, carbon and mercury targets bombarded by 3 GeV and 1 MW proton beam produce muons and neutrons to provide to muon and neutron instruments. As the samples irradiated by muons and neutrons produce radioactive materials, an estimation of the radioactive materials produced in the irradiated samples is necessary for the stable operation and management of the facility. Therefore, a sample radio-activity evaluation code was developed using data from the DCHAIN-SP-2001 code. By selecting the irradiation conditions for each experiment and entering the information for each sample, the radio-activity of a sample can be calculated by multiplying the neutron flux by the activation cross section. The code is a servlet application, programed by JAVA, accessible on the Web, and can be used from the internal network. In the future, we will conduct activation experiments on various materials and validate this code.
Uemura, Takero; Fujita, Hiroki; Koike, Yuko; Kubota, Tomohiro; Koarashi, Jun
no journal, ,
To establish a measurement method of surface contamination density of tritium on wiping smear paper using a liquid scintillation counter, the influence of a smear sample in a vial on the counting was studied in this experiment. Measurement vials without smear paper were utilized for making quenching curve for tritiated water and acetone was used as a quencher of optical efficiency. After making the quenching curve, the vials of tritiated water with smear papers were measured and then the efficiency and the quenching index were compared with the quenching curve. As a result, no influence of smear paper on the liquid scintillation counting was found. In this presentation, the above results and the other basic data related to the measurement will be explained.
Sakashita, Koichi; Arakawa, Yuto; Kasugai, Yoshimi; Ishii, Tetsuro
no journal, ,
Radioactive concentration of short-lived gas nuclides produced via air activation by neutron in the hot-cell was measured using a plastic scintillator gas monitor in Materials and Life Science Experimental Facility at J-PARC. However, conversion factors (CF), the ratio of radioactive concentration to count rate, had been unknown for the short-lived nuclides of 
C, 
N and 
O. Therefore we evaluated them with Monte Carlo method using Geant4. As a result, the CF's were shown to be almost constant in the energy region of 
-rays emitted from these short-lived nuclides and 
Ar. Then we adopted the CF of Ar, which is certified by the vendor, as those of the short-lived nuclides.
Kato, Saori; Kasugai, Yoshimi; Saito, Fumihiro; Ito, Takashi; Tanaka, Takeshi*; Sugawara, Masakatsu*; Numajiri, Masaharu*; Bessho, Kotaro*; Nakane, Yoshihiro; Miyamoto, Yukihiro
no journal, ,
Three kinds of video materials on the radioactive material leak accident which happened in J-PARC on May 23, 2013 have been produced. These have been screened on the "J-PARC Safety Day" to encourage the J-PARC staff members to keep the memory, to pass on the lessons learned to the next generation, and to use them for future safety.
Saito, Fumihiro; Kasugai, Yoshimi; Bessho, Kotaro; Nakane, Yoshihiro
no journal, ,
"Safety day", on which all staff members put their safety-related efforts first, has been assigned on a certain day in late May every year in J-PARC. This is an approach to make a safer environment in J-PARC, learning from the radioactive material leak accident happened on May 23, 2013, to raise the safety consciousness of every staff and foster a safety culture at J-PARC. There are four main programs that have been held on "Safety Day" so far: meeting for sharing safety information, safety awards, lectures on safety matters, and watching the documentary video on the material leak accident. The details will be shown in the presentation.