Abstract
A magnitude 9.0 great earthquake, the 2011 off the Pacific coast of Tohoku Earthquake, occurred on March 11, 2011, and subsequent Fukushima Daiichi Nuclear Power Station (Fukushima NPS) accidents stirred up natural radiation around the campus of Fukushima Medical University (FMU). FMU is located in Fukushima City, and is 57 km to the northwest of Fukushima NPS. Due to temporary failure of the steam boilers, the air conditioning system for the animal rooms, all autoclaves, and a cage washer could not be used at the Laboratory Animal Research Center (LARC) of FMU. The outside air temperature dropped to zero overnight, and the temperature inside the animal rooms fell to 10°C for several hours. We placed sterilized nesting materials inside all cages to encourage rodents to create nests. The main water supply was cut off for 8 days in all, while supply of steam and hot water remained unavailable for 12 days. It took 20 days to restore the air conditioning system to normal operation at the facility. We measured radiation levels in the animal rooms to confirm the safety of care staff and researchers. On April 21, May 9, and June 17, the average radiation levels at a central work table in the animal rooms with HEPA filters were 46.5, 44.4, and 43.4 cpm, respectively, which is equal to the background level of the equipment. We sincerely hope our experiences will be a useful reference regarding crisis management for many institutes having laboratory animals.
