Radiation Fields in Siemens-Designed PWRs

摘要

In the last three decades, sixteen pressurized water reactors designed by Siemens-KWU have been commissioned in Germany and elsewhere. The design, materials and operating condition (water chemistry) of these reactors have been progressively modified in successive units. Early plants exhibited rather poor performance from the viewpoint of radiation fields, especially caused by Co-60. However, recently they have shown some improvements based on the introduction of reasonable countermeasures. The latest plants have a much improved performance with occupational radiation exposure rates well below 0.5 man-Sv/year. This group of plants started operation between 1985 and 1989. This paper will describe the actual status of the radiation fields in Siemens-KWU-designed PWRs by giving an overview on all plants discussing the countermeasures introduced, and will present the results obtained in two specific cases, namely Philippsburg-2 and Obrigheim.