Radiation control in LHD and radiation shielding capability of the torus hall during first campaign of deuterium experiment

Kobayashi, Makoto; Saze, Takuya; Ogawa, K.; Isobe, M.; Tanaka, Masahiro; Nishimura, K.; Hayashi, Hiroshi; Kobuchi, T.; Yokota, Mitsuhiro; Osuna, Masaki; Nakanishi, Hiroyuki; Osakabe, M.; Takeiri, Y.

doi:10.1016/j.fusengdes.2019.03.062

Cited by 3 publications

(2 citation statements)

References 38 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An important goal of the present study was to verify whether the SDD operated with our enhanced PSD procedure can be used for radiation safety. The high-precision measurement of thermal neutrons is important to satisfy the strict safety management plan of D-D experiment in LHD [37,38]. Therefore, the fluctuation of the measured EI count rate was analyzed to evaluate the reliability of the measurement.…”

Section: Real-time Thermal Neutron Measurement In the Lhd Torus Hallmentioning

confidence: 99%

Thermal neutron measurement by single crystal CVD diamond detector applied with the pulse shape discrimination during deuterium plasma experiment in LHD

Kobayashi

Angelone

Yoshihashi

et al. 2020

Fusion Engineering and Design

Self Cite

View full text Add to dashboard Cite

Section: Real-time Thermal Neutron Measurement In the Lhd Torus Hallmentioning

confidence: 99%

Thermal neutron measurement by single crystal CVD diamond detector applied with the pulse shape discrimination during deuterium plasma experiment in LHD

Kobayashi

Angelone

Yoshihashi

et al. 2020

Fusion Engineering and Design

Self Cite

View full text Add to dashboard Cite

“…Therefore, the comprehensive radiation control system has been developed in LHD. The detail of this system can be found elsewhere 5,6) .…”

Section: Introductionmentioning

confidence: 99%

The Evaluation of a Simple Measurement Method using NaI(Tl) Scintillation Survey-Meter for Radiation Safety Management of Radioactivated Armor Tiles of LHD Vacuum Vessel

Kobayashi

Suzuki

Saze

et al. 2021

Radiat. Saf. Manage.

Self Cite

View full text Add to dashboard Cite

In this study, the application of a simple measurement method using NaI(Tl) scintillation survey-meter to detect the gamma-rays in the armor tiles of LHD vacuum vessel exposed to fast neutrons during deuterium plasma experiments was evaluated to control the occupational exposure for the storage of huge numbers of the armor tiles. The gamma-ray spectrometry for an activated armor tile by high-purity germanium detector (HPGe) showed the gamma-ray peaks from 58 Co, 54 Mn and 60 Co. The detection efficiencies of these nuclides for HPGe were evaluated by PHITS to estimate the concentrations of these nuclides. The radiation transport model for HPGe in PHITS were validated by the gamma-ray measurements for sealed gamma-ray sources. Then, the detection efficiencies of these nuclides for NaI(Tl) scintillation survey-meter were also evaluated by the same manner using PHITS. The predicted dose rate of the activated armor tiles in NaI(Tl) scintillation survey-meter was consistent with the actual measurement. The predicted count rate in NaI(Tl) scintillation survey-meter for 60 Co, which will be a deterministic nuclide in the armor tile due to longer half-life, in the clearance level was sufficiently higher than the minimum detectable count rate of NaI(Tl) scintillation survey-meter with a simple shielding for environmental radiation.

show abstract

核融合科学研究所における松葉及び土壌中の環境放射性物質のモニタリング

Nakada

Tanaka

Kato

et al. 2021

Jpn. J. Health Phys.

Self Cite

View full text Add to dashboard Cite

NIFS), the environmental radioactivity in soil and pine needles were measured from 2014 to 2019 as a part of the monitoring activities for deuterium plasma experiments using Large Helical Device (LHD). Among the monitoring nuclides of 54 Mn, 59 Fe, 58 Co, 60 Co, 134 Cs, 137 Cs, 7 Be and 40 K, the nuclides of 137 Cs, 7 Be and 40 K were detected by a HPGe detector. The concentration of 40 K in soil ranged from 530 Bq/kg to 1,068 Bq/kg, which was the same level at the Tono area reported by Hosoda et al. In addition, the concentration of 40 K in pine needles ranged from 125 Bq/kg to 300 Bq/kg and a peak was observed in summer. The maximum concentrations of 7 Be on soil and pine needles were 69.4 Bq/ kg and 31.9 Bq/kg, respectively. The concentration of 7 Be on pine needles became low in summer. Although the concentration of 137 Cs on pine needles was not almost detectable, that on soil ranged from 0.56 Bq/kg to 3.69 Bq/kg. The concentrations of these nuclides remain the same level after starting the deuterium plasma experiment in LHD.

show abstract

Radiation control in LHD and radiation shielding capability of the torus hall during first campaign of deuterium experiment

Cited by 3 publications

References 38 publications

Thermal neutron measurement by single crystal CVD diamond detector applied with the pulse shape discrimination during deuterium plasma experiment in LHD

Thermal neutron measurement by single crystal CVD diamond detector applied with the pulse shape discrimination during deuterium plasma experiment in LHD

The Evaluation of a Simple Measurement Method using NaI(Tl) Scintillation Survey-Meter for Radiation Safety Management of Radioactivated Armor Tiles of LHD Vacuum Vessel

核融合科学研究所における松葉及び土壌中の環境放射性物質のモニタリング

Contact Info

Product

Resources

About