A 3D radiation image display on a simple virtual reality system created using a game development platform

佐藤 優樹; 寺阪 祐太; 小澤 慎吾*; 谷藤 祐太; 鳥居 建男

Journal of Instrumentation (Internet), 13(8), p.T08011_1 - T08011_10, 2018/08

https://doi.org/10.1088/1748-0221/13/08/T08011

The Fukushima Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., suffered a meltdown after a large tsunami caused by the Great East Japan Earthquake on March 11, 2011. The measurement of radiation distribution inside FDNPS buildings is indispensable for executing appropriate decommissioning tasks in the reactor's buildings. In addition, it is extremely important to accurately predict the location of radioactive contamination beforehand because the working time is limited owing to radiation exposure to workers. In this paper, a simple virtual reality (VR) system that can detect radioactive substances in virtual space has been developed to simulate real working environments. A three-dimensional (3D) photo-based model of the real working environment, including an image of the radioactive substance, was imported into the virtual space of the VR system. The developed VR system can be accessed using a smartphone and a cardboard goggle. The VR system is expected to be useful for preliminary training of workers and for recognizing radioactive hotspots during decommissioning of the work environment.

Remote radiation imaging system using a compact -ray imager mounted on a multicopter drone

佐藤 優樹; 小澤 慎吾*; 寺阪 祐太; 冠城 雅晃; 谷藤 祐太; 川端 邦明; 宮村 浩子; 和泉 良*; 鈴木 敏和*; 鳥居 建男

Journal of Nuclear Science and Technology, 55(1), p.90 - 96, 2018/01

https://doi.org/10.1080/00223131.2017.1383211

A remote radiation imaging system comprising a lightweight Compton camera and a multicopter drone was developed to remotely and quickly measure radioactive contamination inside the buildings of the Fukushima Daiichi Nuclear Power Station (FDNPS). The drone system is used for measuring detailed radiation distributions in narrow areas, which have been difficult to gauge with conventional aircraft monitoring using helicopters. A measurement of radiation distributions in outdoor environments in the coastal areas of Fukushima, Japan, was performed. The drone system with the Compton camera succeeded in remote observations of dense hotspots from the sky over a contaminated area near the FDNPS. The time required for image reconstruction is approximately 550 s in the case of a 9-m flight altitude for the hotspots with a surface dose rate of several tens of Sv/h. This drone system will be used inside the buildings of the FDNPS for remote measurement of radioactive contamination.

Radiation imaging system using a compact -ray imager mounted on a remotely operated machine

佐藤 優樹; 川端 邦明; 小澤 慎吾*; 和泉 良*; 冠城 雅晃; 谷藤 祐太; 寺阪 祐太; 宮村 浩子; 河村 拓馬; 鈴木 敏和*; et al.

IFAC-PapersOnLine, 50(1), p.1062 - 1066, 2017/07

https://doi.org/10.1016/j.ifacol.2017.08.218

The development of remote and quick radiation imaging methods in the high dose-rate environment is requested to accelerate implementation of decommissioning of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP). We developed the remote radiation imaging system consisting of a Compton camera and a multicopter drone to remotely measure the radioactive contamination on the several radioactive fields in the environment and inside the building of nuclear facilities such as the FDNPP. The drone system succeeded in the observation of several hotspots from the sky at the outdoor environments in coastal areas of Fukushima, Japan. In addition, we are now developing the SLAM technology for remotely operated machines such as the drone to complete the remote radiation imaging system, which can autonomous flight.

小型・軽量コンプトンカメラを用いた遠隔放射線イメージング技術の開発,2; 福島県浜通り地域でのコンプトンカメラのイメージング精度検証

寺阪 祐太; 佐藤 優樹; 冠城 雅晃; 小澤 慎吾*; 鳥居 建男

no journal, , 

開発した小型・軽量コンプトンカメラを用いて福島県浜通り地域でフィールド試験を実施した。コンプトンカメラをドローンに搭載する前段階として、コンプトンカメラ単独で環境中に局所的に線量率が高いホットスポットをイメージング可能であるかを検証した。

Compact Compton camera for radiation distribution imaging under high dose rate environments

佐藤 優樹; 寺阪 祐太; 冠城 雅晃; 谷藤 祐太; 宇佐美 博士; 宮村 浩子; 小澤 慎吾*; 和泉 良*; 川端 邦明; 鈴木 敏和*; et al.

no journal, , 

The development of quick radiation imaging methods in the high dose rate environments is very important to accelerate decommissioning of the Fukushima Daiichi Nuclear Power Station (FDNPS). We have developed a compact Compton camera for measurement of radioactive contamination inside FDNPS. We conducted a performance evaluation test inside the -ray irradiation facility, and the Compton camera can visualize the Cs-irradiation source under the dose rate of 1 mGy/h. We also developed the remote radiation imaging system consisting of the Compton camera and a multicopter-type drone. The drone system succeeded in observing the Cs-radioactive source, which was set on the floor surface, remotely. We plan to use the Compton camera and the drone system inside the buildings of FDNPS.

Radiation image display on a simple virtual reality system

佐藤 優樹; 小澤 慎吾*; 谷藤 祐太; 鳥居 建男

no journal, , 

The Fukushima Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., went into meltdown after the large tsunami caused by the Great East Japan Earthquake of March 11, 2011. Radiation distribution measurements inside the buildings of the FDNPS are indispensable to execute the decommission tasks because the information would be important to predict risk to workers and to decrease the amount of radiation exposure. In this work, we developed a simple virtual reality (VR) system that can perceive the radioactive substances in the virtual space reproducing working environments. The VR was developed with Unity 5.6 which is a game development engine. The developed VR will be experienced using a smartphone and a cardboard goggle. The advantage of using smartphones is that it has a gyro sensor, which users can use to look over the VR space. In addition, it is owned by many users. The VR system is expected to be useful for preliminary training of workers and recognition of radioactive hot spots in the decommissioning work environment.

放射線分布の3次元表示方法及び装置

鳥居 建男; 佐藤 優樹

小澤 慎吾*; 菅原 洋*

特願 2018-173023  公開特許公報  特許公報

【課題】地表の広い範囲における放射性物質の位置を高精度で検出して3次元表示可能とする。 【解決手段】3次元位置を検出可能な移動体(ドローン10)に搭載された放射線検出器(コンプトンカメラ20)を用いて放射線を測定し、前記移動体(10)の移動に伴って得られる複数位置での前記放射線検出器(20)による測定結果と前記移動体(10)の3次元位置情報とを用いることによって、放射線分布の3次元マップを作成し、該放射線分布の3次元マップを、3次元の地形データ又は航空写真と重ね合せて表示する際に、放射線検出器(20)による放射線測定値を、地表(6)面の単位面積毎の測定にかかった時間に応じて時間補正する。更に、放射線検出器(20)と地表(6)面の距離に応じて距離補正したり、放射線検出器(20)に対する放射線の入射角度に応じて角度補正したりすることもできる。