A PHWR should be refueled everyday while the reactor is working.
For this purpose, there is a fuel exchange machine, as shown in
Fig. 1. Since the fuel refueling takes place within a 9 mheight, there
is large space in front of the Calandria, which is a reactor room. In
addition, the radiation level is so high during the on-power state
that maintenance is carried out behind the shelter wall. The wall
moves on the guide rail in the ditch with a width of 75 cm and
depth of 25 cm, as shown in Fig. 1. It was noted that there is a service
area with a passing gate with a height of 2 m and width of
1.5 m.