Preliminary radiological consequence estimate for a reference LEU core for PARR

Radiological consequence analysis of a reference LEU core for Pakistan Research Reactor (PARR) has been carried out using mathematical models. Three modes of leakage from reactor building have been considered. These are exhaust through the normal ventilation system, through emergency ventilation system and leakage from the building. The whole body and thyroid does have been calculated for the duration of 2 hours and 30 days at the boundaries of exclusion zone at 450m and low population zone at 100m. For the releases at stack height through normal and emergency ventilation systems, does at both the boundaries remain within relevant emergency does limits of 300 rem for thyroid and 25 rem for whole body. However, in case of direct release from the containment building, limiting thyroid does of 300 rem, at 1000m, for 30 days exposure is achieved for a leak rate of 27% per day under Pasquill condition E. The results presented in this report are only preliminary estimates. A more accurate detailed analysis, for various burnups, will be carried using standard computer codes. (orig./A.B)