Comparison of the Thermal Performance of Damaged and Intact Shock Absorber

Regulatory requirements for a Type B package are specified in the Korea MEST Act 2009-37, IAEA Safety Standard Series No. TS-R-1, and US 10 CFR Part 71. These regulatory guidelines require that a Type B package for transporting radioactive materials should be able to withstand a test sequence consisting of a 9 m drop onto an unyielding surface, a 1 m drop onto a puncture bar, and a period of 30 min under a thermal condition of 800 °C. To evaluate the thermal shielding effect of a shock absorber, a thermal test was performed using a half scale model with shock absorber, which was damaged by both a 9 m drop test and a 1 m puncture test. For the purpose of comparison, the thermal test was also carried out using a half scale model with intact shock absorber. The maximum temperature of the seal in the upper part was measured at 273 °C, which is higher than the manufacturer's recommended maximum temperature in the thermal test using damaged shock absorber. This is because the shock absorber, which was broken in the drop test, was almost burned. However, the maximum temperature of the seal in the upper part was measured at 249 °C, which is lower than the manufacturer's recommended maximum temperature in the thermal test using intact shock absorber. Therefore, to maintain the containment boundary of the hot-cell cask, it is important that the manufacturing of the shock absorber prevent failure of shock absorber housing.