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Journal Articles

The Japan Health Physics Society Guideline on Dose Monitoring for the Lens of the Eye

Yokoyama, Sumi*; Tsujimura, Norio; Hashimoto, Makoto; Yoshitomi, Hiroshi; Kato, Masahiro*; Kurosawa, Tadahiro*; Tatsuzaki, Hideo*; Sekiguchi, Hiroshi*; Koguchi, Yasuhiro*; Ono, Koji*; et al.

Journal of Radiation Protection and Research, 47(1), p.1 - 7, 2022/03

Background: In Japan, new regulations that revise the dose limit for the lens of the eye (the lens), operational quantities, and measurement positions for the lens dose were enforced in April 2021. Based on the international safety standards, national guidelines, the results of the Radiation Safety Research Promotion Fund of the Nuclear Regulatory Authority, and other studies, the Working Group of Radiation Protection Standardization Committee, the Japan Health Physics Society (JHPS) developed a guideline for radiation dose monitoring for the lens. Materials and Methods: The Working Group of the JHPS discussed the criteria of non-uniform exposure and the management criteria set to not exceed the dose limit for the lens. Results and Discussion: In July 2020, the JHPS guideline was published. The guideline consists of three parts: main text, explanations, and 26 questions. In the questions, the corresponding answers were prepared, and specific examples were provided to enable similar cases to be addressed. Conclusion: With the development of guideline on radiation dose monitoring of the lens, radiation managers and workers will be able to smoothly comply with revised regulations and optimise radiation protection.

Journal Articles

Development of guidelines on radiation protection for the lens of the eye in Japan

Yokoyama, Sumi*; Iwai, Satoshi*; Tsujimura, Norio; Hashimoto, Makoto; Yoshitomi, Hiroshi; Kato, Masahiro*; Kurosawa, Tadahiro*; Tatsuzaki, Hideo*; Sekiguchi, Hiroshi*; Koguchi, Yasuhiro*; et al.

Proceedings of 15th International Congress of the International Radiation Protection Association (IRPA-15) (Internet), 8 Pages, 2022/00

Journal Articles

The Concept of dose system for radiological protection

Hirayama, Hideo*; Nakashima, Hiroshi; Sanami, Toshiya*; Yamaguchi, Yasuhiro; Sato, Osamu*; Takagi, Shunji*; Suzuki, Toshikazu*; Iwai, Satoshi*

Nihon Genshiryoku Gakkai-Shi ATOMO$$Sigma$$, 55(2), p.83 - 96, 2013/02

Since the accident at the Fukushima Daiichi Power Plant, units of radiation doses such as Sv have been frequently reported by newspapers. However, it is not exactly understood even by experts on nuclear engineering that there are two different concepts which are the protection quantity such as the effective dose related to a radiation health risk and the practical quantity such as ambient dose equivalents related to measurements. In this special issue, Radiological Protection Quantity, and Operational Quantity and Radiological Protection Quantity, explain the radiation protection dose system including the protection and practical quantities established by ICRP and ICRU. Relation between Dosimeters used at Fukushima etc. and Radiological Protection Quantity describes a method and its problems to measure radiations from Cs on surface and underground using survey meters and personal dosimeters, and convert the measured values to effective doses.

Journal Articles

Application of voxel phantoms and Monte Carlo method to whole-body counter calibrations

Kinase, Sakae; Takagi, Shunji*; Noguchi, Hiroshi; Saito, Kimiaki

Radiation Protection Dosimetry, 125(1-4), p.189 - 193, 2007/07

 Times Cited Count:16 Percentile:74.03(Environmental Sciences)

In the Japan Atomic Energy Research Institute (JAERI), a calculation code -UCWBC code- for whole-body counter calibrations using voxel phantoms has been developed as an EGS4 Monte Carlo user code. To validate the UCWBC code for calibrating whole-body counters in JAERI, response functions and counting efficiencies of a p-type high-purity Ge semiconductor detector used for the whole-body counter were evaluated for a water-filled block-shape phantom by the UCWBC code and were measured by experiments. Furthermore, counting efficiencies of the Ge semiconductor detector for the male and female voxel phantoms developed in JAERI were evaluated in the photon energy range 60-1836 keV by the UCWBC code in order to examine the differences between the counting efficiencies for voxel phantoms. In conclusion, it was found that the response functions and counting efficiencies of the Ge semiconductor detector by the UCWBC code for the water-filled block-shape phantom are in good agreement with measured data. The UCWBC code was validated by the comparisons.

Journal Articles

Investigations of different kilovoltage X-ray energy for three-dimensional converging stereotactic radiotherapy system; Monte Carlo simulations with CT data

Deloar, H. M.*; Kunieda, Etsuo*; Kawase, Takatsugu*; Tsunoo, Takanori*; Saito, Hidetoshi*; Ozaki, Masahiro*; Saito, Kimiaki; Takagi, Shunji*; Sato, Osamu*; Fujisaki, Tatsuya*; et al.

Medical Physics, 33(12), p.4635 - 4642, 2006/12

 Times Cited Count:13 Percentile:40.88(Radiology, Nuclear Medicine & Medical Imaging)

We are investigating three-dimensional converging stereotactic radiotherapy for small lung tumors with better dose homogeneity at the target. A computed tomography radiotherapy was simulated with BEAMnrc X-ray energy of 147.5, 200, 300, and 500 kilovoltage system was validated by comparing calculated and measured percentage of depth dose in a water phantom for the energy of 120 and 147.5 kVp. A thorax phantom and CT data from lung tumors compare dose homogeneities of kVp energies with MV energies of 4, 6, and 10 MV. Three non-coplanar arcs of the target were employed. The Monte Carlo dose data format was converted to the XiO RTP format to compare dose homogeneity, differential, and integral dose volume histograms of kVp and MV energies. In terms of dose homogeneity and DVHs, dose distributions at the target of all kVp energies with the thorax phantom were better than MV energies, with mean dose absorption at the ribs of 100%, 85%, 50%, 30% for 147.5, 200, 300, and 500 kVp, respectively. Considering dose distributions and reduction of the enhanced dose absorption at the ribs, a minimum of 500 kVp is suitable for the lung kVp 3DCSRT system.

Journal Articles

Dose calculation using Japanese voxel phantoms for diverse exposures

Saito, Kimiaki; Sato, Kaoru; Kinase, Sakae; Noguchi, Hiroshi; Funabiki, Jun*; Takagi, Shunji*; Sato, Osamu*; Emoto, Yutaka*; Koga, Sukehiko*

Proceedings of Monte Carlo 2005 Topical Meeting (CD-ROM), 14 Pages, 2005/00

The voxel phantoms for Japanese male and female adults developed from CT data have been utilized for radiation protection purposes. User codes based on the EGS4 Monte Carlo program have been constructed to calculate external and internal exposures for photons and electrons. The calculated doses were compared with those using stylized MIRD type and other phantoms. The difference for external dose is not simply explained by the difference in body size, but the positions of organs were found to be an important factor to determine the doses. In internal exposure, the positional relations among organs drastically affect the specific absorption fractions, if the source and target organs are different. The simple approximation which has been used by ICRP to evaluate the dose at the boundary of two different media was found to give S values being too conservative. These calculated data shows the usefulness of realistic voxel phantoms combined with the Monte Carlo calculations.

Journal Articles

Evaluation of counting efficiency of whole-body counter using voxel phantoms

Kinase, Sakae; Takagi, Shunji*; Noguchi, Hiroshi; Saito, Kimiaki

Proceedings of 11th International Congress of the International Radiation Protection Association (IRPA-11) (CD-ROM), 7 Pages, 2004/05

The present study was performed to validate the UCWBC code for calibrating in vivo measurements. Furthermore, the calibration data for the adult voxel phantoms developed in JAERI were evaluated by the UCWBC code in order to examine the differences between the calibration data for voxel phantoms, including a voxel version of water-filled block-shape phantom based on an actual phantom that is used for the calibration of the whole-body counter in JAERI. It was found that the calculated calibration data by the UCWBC code for the water-filled block-shape phantom show good agreement with measured ones. Consequently, the UCWBC code was validated by the comparisons. It was also found that the calibration data depend on phantoms of different sizes and the effective distance between phantom and detector. The calibration of in vivo measurements using voxel phantoms for individuals would be quite useful for the improvement in accuracy of the measurement results.

Journal Articles

Progress in physics and technology developments for the modification of JT-60

Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.

Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02

 Times Cited Count:2 Percentile:6.67(Physics, Fluids & Plasmas)

The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-$$beta$$. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.

Journal Articles

Objectives and design of the JT-60 superconducting tokamak

Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Chujo, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.

Nuclear Fusion, 43(7), p.606 - 613, 2003/07

no abstracts in English

Journal Articles

Objectives and design of the JT-60 superconducting tokamak

Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Cho, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.

Nuclear Fusion, 43(7), p.606 - 613, 2003/07

 Times Cited Count:33 Percentile:70.69(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Mobile robot with a self-positioning system

Yanagihara, Satoshi; Hatakeyama, Mutsuo; Ito, Hirokuni; Mori, Shunji*; Takagi, Akira*

Advanced Robotics, 15(3), p.293 - 300, 2001/06

 Times Cited Count:1 Percentile:10.41(Robotics)

Automatic measurement of building surface radioactivity must be a useful approach for decommissioning and maintenance activities in nuclear facilities. In particular, in the final step of decommissioning a nuclear power plant, it is essential to confirm that there is no effective radioactivity on building surfaces by measurement. However, experience showed that hands-on measurement using conventional detectors requires a great deal of labor-hours for all building surfaces in relatively large facilities. To realize the automatic measurement of building surface radioactivity, a mobile robot equipped with highly sensitive surface detectors has been developed; it can move automatically based on route plans to measure radioactivity on concrete floors and walls. In the development of this system, efforts were especially made to realize accurate robot motions by applying self-position identification system in consideration of the fact that the measurement should cover all the surfaces of planned areas with minimum overlap.

JAEA Reports

Response calculation of a neutron detector

*; Takagi, Shunji*

PNC TJ9222 98-003, 15 Pages, 1998/03

PNC-TJ9222-98-003.pdf:0.5MB

The responses were calculated for the burnup measurement equipment placed in the spent fuel storage facility beside JOYO by using the continuous energy Monte Carlo code "MCNP-4A". In this work, the responses were calculated without cosidering the neutron multiplication in a spent fuel and were compared to the responses considering neutron multiplication to clarify the effect of neutron multiplication in a spent fuel. The calculated results show that the neutron multiplication in a spent fuel not only increases the count rates but also influence to the axial count rate distribution. This count rate distribution was flattened by the neutron multiplication.

JAEA Reports

Calculation of correction factors for neutron multiplication in spent fuel

*; Takagi, Shunji*

PNC TJ9222 98-002, 40 Pages, 1998/03

PNC-TJ9222-98-002.pdf:1.6MB

The responses have been calculated for the burnup measurement equipment placed in the spent fuel storage facility beside JOYO by using the Monte Carlo code "MCNP-4A". These responses are influenced by the neutron multiplication depending to the burnup of the fuel to be measured. In this work, the dependence of calculated responses to the burnup of fuel was ivestigated using the composition of the irradiated fuels obtained from the burnup calculation with MAGI. These responses were compared to the responses without multiplication. The following relationship between burnup and detector response became clear as the results of these calculations. (1)The burnup of fuel influence to the detector response from the neutron source near the detector, but does not significantly influence to the detector apart from the neutron source. (2)The response from the neutron source near the detector decrease with burnup, and the decrease is proportional to the multiplication; 1/(1-k), except for the case that the neutron source is at the end of fuel region. The burnup dose not significantly influence to the detector response from the neutron source at the end of fuel. The detector responses from the neutron from a spent fuel of arbitrary burnup can be corrected by the hear interpolation for neutron multiplication; 1/(1-k), when the detector closes to neutron source, and no corrections are required when the detector is apart from neutron source. It was also investigated that the effect of considering the gas plenum at the top of fuel and considering fission products in irradiated fuels. The multiplication factor of fuel and detector response were decreased with the model considering gas plenum because of neutron leakage from the void in gas plennum. The axial distribution of the detector response was not influenced by this modeling. The fission products in irradiated fuel cause great negative reactivity, about 6%$$Delta$$k for the burnup of 62,540MWd/t, and decrease ...

JAEA Reports

Shielding calculation of the radiation condition for the surveillance testing

*; Takagi, Shunji*

PNC TJ9222 98-004, 216 Pages, 1998/02

PNC-TJ9222-98-004.pdf:9.72MB

The neutron flux, reaction rate, gamma flux, and gamma were evaluated by using the radiation shielding calculation code for the estimation of the radiation condition for the surveillance testing heating of JOYO reactor core. Neutron reaction cross sections were calculated from the JENDL dosimetry files. The spatial distributions of neutron and gamma flux were evaluated by using two models. One was the RZ model for the axial and radial distribution, and the other was the XY-R$$theta$$ model for the radial and azimuthal distribution. The collapsed effect of the grouped cross section was estimated by the calculation with the RZ model. The effect of the rack fuel was estimated by the calculation with the XY-R$$theta$$ model.

Journal Articles

None

Nojiri, Ichiro; Iwai, Satoshi*; Sato, Osamu*; Takagi, Shunji*; *; *

Donen Giho, (102), p.59 - 66, 1997/06

None

Oral presentation

How should we monitor to adequately estimate equivalent dose of the lens of the eye for radiation workers?

Tsujimura, Norio; Yokoyama, Sumi*; Iwai, Satoshi*; Takagi, Shunji*

no journal, , 

no abstracts in English

Oral presentation

Upscaling and intercomparison of soil respiration in Japan

Yamanuki, Hina*; Ichii, Kazuhito*; Yamamoto, Yuhei*; Kotsuki, Shunji*; Sun, L.*; Liang, N.*; Teramoto, Munemasa*; Nagano, Hirohiko*; Hirano, Takashi*; Takagi, Kentaro*; et al.

no journal, , 

Oral presentation

Refinement of a model for upscaling of soil respiration in Japan

Yamanuki, Hina*; Ichii, Kazuhito*; Yamamoto, Yuhei*; Kotsuki, Shunji*; Sun, L.*; Liang, N.*; Teramoto, Munemasa*; Nagano, Hirohiko*; Hirano, Takashi*; Takagi, Kentaro*; et al.

no journal, , 

Oral presentation

Task Group for the Development of Estimation Codes for Cancer Risk caused by Radiation Exposure

Sasaki, Michiya*; Takagi, Shunji*; Kai, Michiaki*; Furukawa, Kyoji*; Kawaguchi, Isao*; Kudo, Shinichi*; Takahara, Shogo; Otoshi, Kazuki*; Shimada, Kazumasa; Satoh, Daiki

no journal, , 

To contribute to the quantitative discussion of risks associated with low-dose radiation exposure, the Japan Society of Health Physics established the "Task Group for the Development of Estimation Codes for Cancer Risk caused by Radiation Exposure". This presentation will report on the activities conducted during the two-year period from FY2020 to FY2021.

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