Iodine-129 in the Tokai Reprocessing Plant and the environment

Nakano, Masanao

Hoken Butsuri (Internet), 56(1), p.17 - 25, 2021/03

https://doi.org/10.5453/jhps.56.17

The Tokai Reprocessing Plant is the first reprocessing plant in Japan which started hot test in 1977, and had reprocessed 1140 tons of spent nuclear fuel by May 2007. The gaseous and liquid radioactive wastes has been discharged to the environment. Since iodine-129 (I) is one of the most important nuclides for environmental impact assessment. Therefore, I in the exhaust and effluent has been controlled, and a precise analysis method of I in the environmental samples was developed, and the concentration of 129I in the environment was investigated. This report presents an overview of these activities. Not limited to I on reprocessing facilities, it is essential for nuclear operators to reduce the amount released to the environment in the spirit of ALARA, and to continuously develop the further upgrading environmental monitoring methods and evaluation methods in order to foster a sense of safety and security among residents living in the vicinity of the facilities.

Radiation distribution situation seven years after the Fukushima Dai-ichi Nuclear Power Plant Accident and the leading edge of technology for environmental radiation monitoring

Sanada, Yukihisa

Nihon Genshiryoku Gakkai-Shi ATOMO, 61(6), p.453 - 456, 2019/06

no abstracts in English

Using two detectors concurrently to monitor ambient dose equivalent rates in vehicle surveys of radiocesium contaminated land

Takeishi, Minoru; Shibamichi, Masaru; Malins, A.; Kurikami, Hiroshi; Murakami, Mitsuhiro*; Saegusa, Jun; Yoneya, Masayuki

Journal of Environmental Radioactivity, 177, p.1 - 12, 2017/10

AA2016-0534.pdf:1.79MB

https://doi.org/10.1016/j.jenvrad.2017.05.010

By convention radiation measurements from vehicle-borne surveys are converted to the dose rate at 1 m above the ground in the absence of the vehicle. To improve the accuracy of the converted results from vehicle-borne surveys, we investigated combining measurements from two detectors mounted on the vehicle at different heights above the ground. A dual-detector setup was added to a JAEA monitoring car and compared against hand-held survey meter measurements in Fukushima Prefecture. The dose rates obtained by combining measurements from two detectors were within 20% of the hand-held reference measurements. The combined results from the two detectors were more accurate than those from either the roof-mounted detector, or the detector inside the vehicle, taken alone. When radiocesium is deficient on a road compared to the adjacent land, mounting detectors high on vehicles yields dose rates closer to the values adjacent to the road. We also investigated mounting heights for vehicle-borne detectors using Monte Carlo -ray simulations.

Nuclear power plant simulation using multilayer perceptron

Ono, Tomio*; Subekti, M.*; Maruyama, Yuta*; Nabeshima, Kunihiko; Kudo, Kazuhiko*

Dai-13-Kai Interijento, Shisutemu, Shimpojiumu Koen Rombunshu, p.212 - 217, 2003/12

In this research, we present nuclear power plant simulation method using Multilayer Perceptron, which is one of the models of Artificial Neural Networks(ANNs). The major characteristics of ANNs are to obtain the model through learning, analogy and very high speed processing. Furthermore, 'time synchronizing signal' and 'progress synchronizing signal' are added as the inputs to adapt the abnormal events with various scales or progress rates. This ANN, learned some sample data, can be flexibly adapted to simulate the abnormal events with different scales including explicit progress rates. In the verification using PWR simulator, we confirmed that this method could model NPP abnormal events by learning data and simulate the data which have different progress rates from learning data.

Nuclear reactor monitoring with the combination of neural network and expert system

Nabeshima, Kunihiko; Suzudo, Tomoaki; Ono, Tomio*; Kudo, Kazuhiko*

Mathematics and Computers in Simulation, 60(3-5), p.233 - 244, 2002/09

https://doi.org/10.1016/S0378-4754(02)00018-6

This study presents a hybrid monitoring system for nuclear reactor utilizing neural networks and a rule-based real-time expert system. The whole monitoring system including a data acquisition system and the advisory displays has been tested by an on-line simulator of pressurized water reactor. From the testing results, it was shown that the neural network in the monitoring system successfully modeled the plant dynamics and detected the symptoms of anomalies earlier than the conventional alarm system. The real-time expert system also worked satisfactorily in diagnosing and displaying the system status by using the outputs of neural networks and a priori knowledge base.

Hybrid monitoring system for high temperature gas cooling reactor

Nabeshima, Kunihiko; Tuerkcan, E.*; Suzudo, Tomoaki; Nakagawa, Shigeaki; Inoue, K.*; Oono, Tomio*; ; Suzuki, Katsuo

Proc. of Human-Computer Interaction International'99, 2, p.1187 - 1191, 1999/00

no abstracts in English

Development of nuclear power plant monitoring system with neural network using on-line PWR plant simulator

Nabeshima, Kunihiko; Suzuki, Katsuo; Nose, Shoichi*;

Monitoring and Diagnosis Systems to Improve Nuclear Power Plant Reliability and Safety, 0, p.17 - 26, 1996/00

no abstracts in English

Airborne iodine monitoring at the radioisotope test production plant, JAERI

; ; ;

Proc.1st Intern.Cong.of Radiation Protection,Rome, p.1153 - 1166, 1966/09

no abstracts in English