Full system decontamination at the Obrigheim nuclear power plant prior to decommissioning

In May 2005, the Obrigheim nuclear power station was decommissioned after 36 years of power operation. That same year, the EnBW utility commissioned Areva NP GmbH to conduct a feasibility study of systems decontamination (with regard to chemistry, process technology, and waste volumes) before the plant would be demolished. On the basis of that study and the references produced by Areva NP GmbH, specifically the successful systems decontamination of the Stade reactor prior to demolition, Areva NP GmbH was awarded the contract in 2006 to plan and carry out decontamination of the primary system and the major auxiliary systems of the Obrigheim nuclear power station. The article covers both the HP/CORD UV(R) decontamination technique employed and the objectives and technical execution of systems decontamination. The excellent results obtained in systems decontamination are described in detail. Another point covered in the article are the advantages of full systems decontamination as a central measure preceding demolition. The potential this offers for dose rate reduction in nuclear power plants in operation is indicated. (orig.)