Nuclear Energy System Safety Division
Return to Division Description
To ensure and enhance the safety of various areas of nuclear systems such as nuclear installations and fuels, the Division conducts safety analysis and evaluation (safety evaluations), technical studies for cause and countermeasures of incidents and troubles, development of standards, underlying safety research in a comprehensive manner.
1. Human Factors and Instrumentation and Control System
The Division conducts development of standards, safety evaluation, research activities pertaining to human factors including working processes and organizational management for nuclear systems as well as to highly developed digital I&C technology that has been increasingly applied to nuclear power plants.
2.The Safety of Nuclear Fuel
Using spent nuclear fuels, the Division conducts research and testing of uranium fuel, and uranium and plutonium mixed oxide fuel(MOX fuel) in order to investigate changes in the characteristics of uranium dioxide and changes in metal tubing (cladding tubes), generated during service at nuclear power plants.
3.Phenomena Specific to Nuclear Systems Such as Reactor Physics
The Division conducts analysis and evaluation of such issues specific to nuclear systems as nuclear fission in reactors. Also, the Division conducts research and testing to investigate reactor physics regarding MOX fuel loaded cores.
4.Analysis and Evaluation of Thermal Hydraulic Behavior in Nuclear Installations
Chemical effects testing equipment (PWR sump screen)The Division conducts research and testing, analysis and evaluation of the behavior of reactor coolant when abnormal conditions occur at nuclear power plants. Also, the Division conducts research and testing to establish fire prevention measures for nuclear installations.
5.Aging Management for Nuclear Power Plants
The Division is responsible for research and testing on the conditions for generation of and changes in evolution of defects on vessels and pipes of nuclear power plants to evaluate their integrity. The results obtained are organized into the evaluation method.
The Division precisely evaluates a necessity of aging management on the materials used for vessels and pipes, aiming at strengthening aging management. It also collects the latest engineering insights and encourages the engineering information to be shared among the industry, academia and government.
6.Radiation shielding, exposure and water chemistry of reactors
The Division performs analysis and assessment of radiation shielding and exposure at reactors, develops analysis and assessment methods and studies water chemistry. It also studies measures to reduce occupational exposure at nuclear power stations through international cooperation.
7.Utilization of Probabilistic Safety Assessment (PSA)
The Division conducts quantitative analysis and evaluation on the risk that potentially exists in nuclear power plants by applying PSA method. The insights obtained from the analysis and evaluation are used to enhance the scientific rationality and transparency of the nuclear safety regulations.
8.Severe Accident Countermeasures
The Division conducts analysis, evaluation, research and testing to establish effective measures for preventing a severe accident and mitigating its consequences (an event that may result in significant damage to a reactor core).
9. Safety assessment of fast breeder reactors
Concerning the safety of the fast breeder prototype reactor Monju and future commercial fast breeder reactors, the Division conducts testing and research for improving analytical methods and verifying physical models while focusing on core damage accidents and phenomena unique to fast breeder reactor accidents, such as the behavior of fission products in sodium.
Technical activities to ensure the safety of nuclear systems
