International benchmarking analysis on the evolution of occupational exposures in the Spanish nuclear park

Full text: One of the essential tools for assessing the ALARA principle in the occupational exposure of workers in nuclear facilities is the availability of data on collective doses in order to be able to see the evolution of the implementation of the ALARA principle compared with the plant itself and also with other similar plants (benchmarking analysis). This paper shows a benchmarking analysis on the implementation of the ALARA principle in the Spanish nuclear park based on the evolution of occupational exposure from 1980 to 2006 within an international frame including a detailed individual analysis describing the relevant operations and factors influencing the annual collective dose in the Spanish reactors. For this purpose, data from the ISOE database, world's largest database on occupational exposure data in nuclear power plants, have been used. The analyses shows a common decreasing trend in the evolution of the annual collective dose for both types of reactors in Spain, pressurized and boiling water reactor. Nevertheless, this general decreasing trend shows some temporary increases when analysing individual plants. A decade ago, the relationship between collective doses in Spain and the total of reactors participating in ISOE was inverted being since 1997 lower than the average doses in the ISOE world. This reduction is the result of a jointly effort between the regulator and the utilities being a major achievement regarding the ALARA implementation in Spain. However, we cannot afford to become complaisant as there are still some challenges to face at the level of individual reactor. Details of this challenges are also presented in this paper. (author)