Comparison of occupational exposure according to dismantling strategy of Kori nuclear power plant unit #1 bio-shield

Highlight• Two strategies were analyzed focused on the cutting process. • The worker's dose during cutting was assessed in accordance with the ALARA principle. • Additional costs were calculated considering collective dose and equipment cost. In this study, to evaluate the occupational exposure during dismantling of the bio-shield of the Kori nuclear power plant unit #1, the strategy and process of dismantling the concrete of the bio-shield were analyzed. Two strategies (cutting activated concrete prior to non-activated concrete and vice-versa) were analyzed with a focus on the cutting process, which differs significantly depending on the dismantling strategy, and additional costs related to the cutting equipment and disposal process were calculated accordingly. VISIPLAN was used to evaluate occupational exposure during cutting, and the exposure dose was assessed using the ALARA principle. The strategy where activated concrete was cut prior to non-activated concrete was evaluated to be 47% more inexpensive than the other strategy while satisfying the annual dose limit for workers in economic terms.