JANUS has developed codes suited to various types of fields for atmospheric dispersion, from plume models to 3D modeling, and conducts analysis such as the atmospheric advection diffusion of radioactive materials and environmental impact evaluation.
To evaluate radiation exposure at nuclear power plants, an exposure dose evaluation system in normal operation and severe accident, as well as a gamma ray exposure evaluation system have been developed.
In the event of a nuclear disaster, JANUS deploys and runs an emergency environmental impact evaluation system to quickly conduct an exposure evaluation of the surrounding area if radioactive materials are released into the atmosphere after an accident, and also creates a disaster prevention map required for implementing disaster prevention measures.
Exposure dose evaluation
JANUS provides systems that cover all work related to annual exposure dose evaluation at nuclear power plants in normal operation as well as estimated exposure dose evaluation after an accident.
The exposure dose evaluation system (PC version) is designed as a single, integrated system package that covers all the work related to exposure dose evaluation. The package reduces the amount of work required by your staff, and ensures that results can be determined quicker and with a greater level of accuracy. The results of statistical processing of weather data and the impact on the general public after the plant starts operating can also be verified easily.
Gamma ray exposure evaluation
JANUS is developing a system that provides a comprehensive level of support for calculating the dose rate of ƒÁ rays released from the nuclear reactor building. A service is also available for analyzing the direct and skyshine doses.
The system incorporates various existing analysis codes, and allows various data to be created and managed through the GUI (Graphical User Interface), as well as plotting graphs based on analysis results. The system also includes a preview function for the geometric shape of buildings, allowing visual verifications of input data for a high response capability, even when dealing with complex shapes.
Emergency environmental impact evaluation system
JANUS provides an emergency environmental impact evaluation system for conducting real-time prediction evaluation of exposure doses around nuclear power plants in the event of an emergency situation.
To ensure that the latest data is always used, the system regularly receives weather data observed at the site via online communications between a site data acquisition system. In addition to these data, predicted weather data evaluated with weather models using GPV data, that are grid point values forecasting released by Japan Meteorological Agency, can be used for quick prediction evaluation of exposed radiation dose around the site. Dose evaluation can also be conducted with virtual meteorological condition specified by a user.
Disaster prevention map
JANUS organizes the necessary resources for conducting monitoring work during emergencies, including fixed monitoring posts and monitoring stations installed at nuclear power plants in Japan, various different locations for taking environmental samples, population distribution maps by direction, and population distribution maps by human settlements.
JANUS also operates digital versions of all map data released by the Geospatial Information Authority of Japan, monitoring point data owned by power utility companies, and population data, allowing it to organize the most up-to-date resources for monitoring during emergency situations.
JANUS has developed the codes to predict radioactive source strength and work environment dose rates within the reactor containment vessels. Those codes simulates radioactive crud transport and accumulation behavior within the reactor vessel accounting for the effects of new water chemistry management methods in Japan such as hydrogen injection and zinc addition.
JANUS also has installed various water chemistry related codes such as radiolysis and corrosion potential analysis through partnership with ALARA Engineering (Sweden). JANUS has a wealth of knowledge and experience with analysis and evaluation using the developed and installed codes.
Numerical simulation of the environmental transport of radioactive materials
JANUS provides comprehensive technical support for environmental transport evaluation of radioactive materials, from developing models to conducting exposure dose evaluation.
Evaluations are conducted on each individual environmental medium by applying specific tools: JANUSf atmospheric dispersion simulation tool that includes a meteorological model for the transport of radioactive materials in the atmosphere; tools such as dynamic terrestrial food chain models for the transport of radioactive materials on agricultural land; and using distributed water catchment area models as well as pond, lake and reservoir models for the transport of radioactive materials in the aquatic ecosystems. Numerical simulations are also conducted for the transport of radioactive materials in the coupled environments that span numerous interfaces between each environment.
Nuclear power plant fire protection
JANUS provides a range of services aimed at supporting the various initiatives related to fire protection measures at nuclear power plants in cooperating with research institutes and consulting companies in the US which have considerable experience related to fire protection. Specific services include conducting surveys related to general fire protection topics and fire PRA (site tours, literature surveys etc.), fire testing, and analysis work.