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  • Explosion Safety Research Group

    Explosion Safety Research Group

    Ken Okada
    Group Leader:Ken Okada

    6 Researchers:
    Shiro Kubota, Tomoharu Matsumura, Miyako Akiyoshi, Yuta Sugiyama, Takahiro Tamba

    6 Contract Employees

    Outline

    We are conducting a wide variety of research, from basic to applied, related to explosion safety, such as safety evaluation methods and visualization techniques, technologies to reduce the effects of explosions, and safety evaluation of batteries, in order to advance the understanding of ignition and explosion phenomena of high-energy materials, as typified by explosives.
    We also actively respond to the governmental needs for explosives and conduct large-scale field experiments on explosives. The results obtained are reflected in the creation of standards for safe explosives handling technology, and are also used to help formulate international standards for the handling of hazardous materials through proposals for UN testing, thereby contributing to the realization of a safe and secure society.

    Research Highlights

    Development of Methods and Techniques for Evaluating and Mitigating Explosion Effects

    Explosion Tests in the Field

     

    • Assessing the effects occurring at the time of explosion (blast wave, fragment characteristics, ground vibration, radiant heat, explosion sound)
      • Developing technologies to reduce the explosion effects
      • Reduction of required safety distance for more effective space utilization, etc.
      • Obtaining scientific evidence and basic data for amendment of Explosives Control Act

    → Contributing to the formulation of standards for techniques for handling explosives

    Detonation of ANFO explosive

    Ref: Report on technical standard for explosion mitigation of explosives (2016)

     

    Small-scale indoor experiments
    • Complementing field experiments with multi-point measurements and optical visualization.
    • Development of technology to reduce blast effects by buffer materials.

     

    Optical visualization of shock front of blast wave

    Blast isobaric diagram

    Ref: Report on technical standard for explosion mitigation of explosives (February 2021)

     

    Numerical Calculation Techniques

    Developing techniques for predicting effects of explosions based on numerical calculations that are highly precise and computationally fast

     

    Modeling of magazines
    for explosives

    Simulation results of gases produced by explosion

     

    International contributions for explosion safety

    Classification of Explosives and Energetic Materials for Safety
    • Participation in TDG and GHS organized by the United Nations and international coordination of chemical substance regulations.
    • Contributed to the formulation of international standards for the handling of hazardous substances by proposing MTC.

     

    Evaluation Techniques for Explosion Safety for Energetic Materials

    Explosivity evaluation by exothermic decomposition energy
    • Development of “Method for measuring exothermic decomposition energy as a method for evaluating the explosive hazard of chemical substances, JIS K4834.
    • Development of accurate exothermic hazard evaluation method for chemical substances that react with metal containers.

    ☛Gold plating ≠ gold

    ☛☛There are different types of glass containers on the market, and the results differ.

     

     

     

    Ammonium nitrate exothermic decomposition energy

    Development of advanced JIS for stability testing of explosives.

    • A method for quantifying gases generated from explosives containing nitrocellulose and for evaluating the stability of explosives with high precision was added to JIS.
    • Amended JIS K 4810(2023).
    • Standardization of MV test method and test papers using methyl violet paper was added to JIS.
    • Amended JIS K 4822(2023).

     

    BJS test tube

    Safety evaluation of batteries
    • Applied evaluation technology for safely detonating explosives to battery safety evaluation.
    • Battery safety evaluation methods by evaluating thermal runaway of LIBs and gases generated in 1.5L heating vessels and 20L pressure vessels.

    1.5L heating vessel

     

    Development of technologies for more effective use of explosives

    High-Efficiency Production Technique for Detonation Nanodiamond

    Development of original explosion device

    → Patent of production method at a low-cost and high-efficiency

     

    Development of Functional Materials by Shock Compression

    Light-emitting materials, carbon based materials, etc.

     

    Synthesis of energetic materials having  nanostructures

    Synthesis of nano-nitrocellulose

    → Improvement of combustibility and application to new devices