In 2015,the whole body counter of the Department of Radiation Safety was retrofitted.The whole body counter was used for monitoring radiation workers’internal exposure doses.One of the contents in this project was the retrofit of a ventilation and radon reduction system in the low In 2015, the whole body counter of the Department of Radiation Safety was retrofitted. The whole body counter was used for monitoring radiation workers’ internal exposure doses. One of the contents in this project was the retrofit of a ventilation and radon reduction system in the low