Pre-decommissioning operations

These include the preliminary actions previous to washing and rinsing the system (which might have caused corrosion damage). Initially cleaning all the circuits and components of sodium for examination and sampling purposes was contemplated. In any case, sodium removal is necessary as it reduces the chemical and radioactive risks of future work. First, all the standard and experimental fuel assemblies (120 in all) were unloaded from the reactor vessel, put into containers and stored in the cooling pond or in a dry well in the normal manner. The fertile assemblies (240) and the six control rods were also unloaded and dismantled in the hot cell normally used for the disposal of irradiated equipment. 

it is interesting to examine what the remaining radioactivity of the primary system was composed of Table 8.2 below gives an inventory dated 1 January 1984. After the 

The sodium source of Na from activation and Cs as the main contaminant was negligible numerically compared to the others, but active enough to necessitate preventive measures during the washing and decontamination operations, as explained below. 

These values were obtained from calculations adjusted to a few meeisurements. For the reactor vessel, for instance, the °Co radioactivity was deduced from direct measurements in the reactor vessel and by gamma counting of a few samples extracted from the assembly support plate. These were made of stellite, a high nickel content alloy. 

TABLE 8.2. RADIOACTIVITY INVENTORY OF THE RAPSODIE REACTOR BEFORE DISMANTLING AS OF 1.1.1984 (VALUES AS OF 1.1.1994 IN PARENTHESIS). 

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Pre-decommissioning operation took place from 1984 to 1986 with the removal of fuel and... 

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