Possibilities for the Rehabilitation of Settlements Affected by Large Scale Radioactive Contamination

Full text: Rehabilitation of contaminated settlements is an important issue in planning nuclear emergency management. The decisions must be based on the calculation of the dose avertable by certain decontamination methods and on the optimisation of the reclamation strategy applying the best of these techniques, with the full consideration of all possible aspects. The optimisation procedure requires the knowledge of the efficiency of different techniques, in terms of avertable dose, costs, public acceptance, feasibility etc. With the support of the IAEA a decontamination study was conducted in the highly contaminated area of Masany, Belarus, an abandoned settlement in the exclusion zone, close to the Ukrainian border and only a few kilometres away from the Chernobyl NPP. The study was conducted in and around a village house, trying several traditional and new techniques to reduce the potential indoor and outdoor doses to the inhabitants who would live in such buildings. The following methods were tested on the surfaces of the house: cleaning the roof with a high pressure hot water jet and with the use of a special roof-cleaning trolley, cleaning the wooden outer walls with the hot water jet and with planning these walls, vacuum cleaning the inner walls. The decontamination factors obtained for the roof cleaning were up to 5, the effect of the inner wall decontamination was less pronounced. Several techniques of decontamination of the land around the house were tested: normal digging, triple digging and removal of topsoil. The latter two proved to be equally efficient with a dose reduction of about 3-5 fold. The details and results of the study will be given in the paper. (author)