The Atomic Fuel Corporation has been paying a great effort for the development of uranium mines in this country since its establishment in 1956. The prospecting has so far been centered on the uranium deposits stretching, round Ningyo-toge Mine.
The underground prospecting investigating on the feasibility of industrialization of the mine has been done with similar method of ordinary metal mines. Moreover, suitable drifting method has been carried out in conjunction with the progress of prospecting on sedimentary uranium deposits.
Although there were many difficulties for the ore reserve calculations because of the wide varieties of the seam thickness and the grades of ores, a suitable method has been applied to the calculation as a result of research.
At present, the stoping method is in the testing stage as the type of the deposit is different from those in other parts of this country and in the world. As preliminary testing, two stoping methods, namely the pillar method and the long wall method using the iron props and caps of the ordinary coal mines have been tested and brought about a success. Aiming at the raising of the efficiency, excavation and face conveying method have been put under testing.
For the safety of the mine, an attention was given to the special nature of the mine as a nuclear source material producting mine and a special policy has been applied in addition to those of the ordinary metal mines.