Institute of Isotopes Co., Ltd.
H-1121 Budapest, Konkoly Thege Miklós út 29-33.
H-1535 Budapest, P.O.B. 851. HUNGARY
Phone (361) 3910891      Telefax (361) 3922575

SLL-01 TYPE PILOT SCALE GAMMA IRRADIATOR

The Pilot-scale gamma-irradiation facility is utilizing Co-60 radiation sources. The maximum amount of activity which can be loaded into the facility is 4.44 PBq (120 kCi).

The SLL-01 type Co-60 gamma irradiator is a Category IV facility. It normally contains 20 Co-60 source capsules (so called torpedoes) each of them can be loaded with 4 Hungarian made sealed Co-60 sources (type CoS-43 HH) of dia 11 mm, height 451 mm, or other sources of the same size.

The Co-60 sources are stored in an underground water pool when not in use. The inner lining of the pool is made of 5-mm thick stainless steel. In storage position the radiation sources are kept (in fully shielded condition) in the source-cage. In this case there is 4.2-m water over the upper level of the sources, which gives adequate radiation protection in the direction of the irradiation chamber.

In order to reach the irradiation position the torpedoes must be lifted from the storage position to the irradiation position. The sources in the cage are cylindrically arranged on a pitch-circle of 280-mm diameter. The design of the tubes holding the sources allows after-loading of the sources. The torpedoes in the cage can be lifted up to irradiation position from the storage position by a hoist mechanism. In the irradiation position the symmetry level of the sources is 80 cm over the floor of the irradiation room.

The size of the irradiation chamber is 4 x 4 x 4 m; it is surrounded by walls made of 1.7 m normal concrete. Safe entrance to the irradiation chamber is ensured by a shielded maze with several turnings (breaks). The entrance door of the maze is made of steel. Access of personnel and transport of products are controlled by safety rules and technology to prevent accidental exposure of personnel or visitors. The irradiation process can be monitored from the control desk in the control room adjacent to the irradiation chamber. The irradiator is operated fully automatically, controlled by an electronic control unit. Irradiation during daytime-operation is performed in the presence of operators by manual or automatic control.