STUDY OF THE POSSIBILITY TO HAVING A MEANS OF STOPPING A HYPOTHETIC CRITICALITY ACCIDENT IN ORPHEE REACTOR TRANSFER CANAL: A TWISTS AND TURNS STORY

摘要

During last decennial review of ORPHEE reactor, located in Saclay, France, regulators ask CEA to examine the possibility to have a means to stop a criticality accident in the transfer canal, resulting from the fall of heavy duty charge on fuel cask stored inside. This postulated criticality accident, occurring under several meters of water, is highly unlikely, but cannot be strictly excluded with the double contingency rule. Moreover, the dimensioning of the means is complexed by the lack of information about how fuel, casks and others objects at the bottom of canal are arranged after the fall of the charge. This paper presents all the course of the study, from preliminary studies about the choice of reference situation for calculation configuration, till the conclusion about impact on availability of installation with a concern about efficiency of system design. The intermediate studies concerning the following problematics are also presented: choice of technological orientations of the means - that conduct to the use of neutronic poison and the resulting problematic for their handling -, preparation and transfer of the poisoned solution to the place of accident, solution injection system and homogenization .