2007:07 Inquiry into the radiological consequences of power uprates at light-water rectors worldwide

In Sweden, most of the nuclear power plants are planning power uprates within the next few years. The Department of Occupational and Medical Exposures at the Swedish Radiation Protection Agency, SSI, has initiated a research project to investigate the radiological implications of power uprates on light-water reactors throughout the world. The project was divided into three tasks:

  1. A compilation of power uprates of light-water reactors worldwide. The compi-lation contains a technical description in brief of how the power uprates were carried out.
  2. An analysis of the radiological consequences at four selected Nuclear Power Plants, which was the main objective of the inquiry. Affects on the radiological and chemical situation due to the changed situation were discussed.
  3. Review of technical and organisational factors to be considered in uprate projects to keep exposures ALARA.

The project was carried out, starting with the collecting of information on the imple-mented and planned uprates on reactors internationally. The information was catalogued in accordance with criteria focusing on radiological impact. A detailed analysis followed of four plants selected for uprates chosen according to established criteria, in line with the project requirements. The selected plants were Olkiluoto 1 and 2, Cofrentes, Asco and Tihange. The plants were selected with design and operation conditions close to the Swedish plants. All information was compiled to identify good and bad practices that are impacting on the occupational exposure. Important factors were discussed concerning BWRs and PWRs which affect radiation levels and occupational exposures in general, and especially at power uprates.

Conclusions related to each task are in detail presented in a particular chapter of the report. Taking into account the whole project and its main objective the following conclu-sions are considered to be emphasized.