🤝 Client:
Collaborative project funded by Japan's Ministry of Economy, Trade, and Industry (METI) with multiple stakeholders, including Toshiba, So Innovation Inc., Hayafuji, and Kokyo Sangyo Co., Ltd.
📩 Request:
Stakeholders needed a specialized solution for measuring the radioactive contamination of Flexible Intermediate Bulk Container (FIBCs) filled with contaminated soil. While Polimaster’s PM5300 FBM model with integrated scales offered effective detection of pollution in one FIBCs, users required to conduct simultaneous inspections of six FIBCs on a truck without unloading them. The system also needed to provide rapid detection and meet strict precision standards to be used in Fukushima’s interim storage facilities.
🚧 Challenge:
The main challenge was adapting the PM5300 FBM model to handle varying levels of contamination in FIBCs within short measurement times (30 to 180 seconds) and from trucks passing at different speeds. Additionally, the system had to accurately measure contamination levels with a precision tolerance of ±18% and provide real-time feedback to truck drivers via signal lights. The main difficulty of the task was the need to use the approximate weight of the bags and to make the highest accuracy for Becquerel to meet the requirements for accuracy in Becquerels per kilogram.
🔍 Solution:
Polimaster engineers developed a custom solution by enhancing the PVT scintillation detectors used in the PM5300 TFBM. Six high-sensitivity detectors were installed to ensure rapid and accurate measurement of soil contamination levels (500 to 100,000 Bq/kg). The firmware and dedicated software were adapted to process varying contamination levels efficiently, allowing for automatic calibration and real-time data transmission.
Further, the system was integrated with a signaling mechanism that triggers lights based on pre-set contamination levels, providing instant instructions to truck drivers. A custom mounting design was implemented to ensure that the detectors could measure radiation effectively from fixed distances, even as trucks moved through the measurement line. The main challenge of measuring Becquerels per kilogram was addressed by averaging the weight of the FIBCs and making the highest accuracy for Becquerel, but Polimaster emphasized that exact weight measurements would improve accuracy.
✅ Outcome:
The customized PM5300 TFBM met all of the client requirements. It provided highly accurate Becquerel measurements, with precision within ±18%, and allowed the detection of contaminated soil while trucks remained stationary or passed through slowly. Although Polimaster developed a successful prototype that met all technical requirements and operated in Fukushima's interim storage facilities, the final system was not widely adopted due to changes in project management. Despite these challenges, the PM5300 TFBM showcased Polimaster’s ability to deliver high-precision solutions for complex contamination measurement tasks.
