Characteristics of irradiation facilities at RTP for NAA activity

At Unit Tenaga Nuklear (UTN), the PUSPATI TRIGA REACTOR (RTP), a 1MW research reactor provides the neutron source required by Neutron Activation Analysis (NAA) activity. Two of its irradiation facilities: the Rotary Specimen Rack (RSR) and the Pneumatic Transfer System (PTS), are mainly used for this purpose. The thermal neutron flux at these facilities at 500kW are 1.59E12 n/cm/sec and 4.92E12 n/cm/sec respectively. As the PTS is located inside the core, the neutron flux are higher. However, the RSR is capable of accommodating 79 samples for irradiation at a time as compared to only 1 for the PTS. Among the first uses of RTP is the irradiation of NAA samples. During 1983, 60% of the reactor operating time was utilised for this purpose and by March 1984, it has increased to 75%. The facilities are mainly used by our own Neutron Activation Analysis group where most of the requests from other institutions are entertained. This paper presents briefly the characteristic of the irradiation facilities, their usage so far, and the problems faced in optimising their utilization. (author)