Premature transfer of a solution Incident niveau 1 sur l'échelle INES

Incident report

April 26, 2005

On April 25, 2004, a solution was transferred from one tank to another in the Centralized Waste Treatment Unit(1) of the UP2 800 plant before an analysis of its characteristics had been completed.

To perform the analysis, the solution must be homogenized using a "stirring ejector". But during preparations for sampling and analysis, a "transfer ejector" was started up. As a result, the solution was transferred to the next tank.<

After-the-fact analytical results indicated that the solution had a much lower value than the authorized limit.

The event was without consequence for personnel or the environment. However, because a similar event had occurred in the past, a proposal was made to the Nuclear Safety Authority to classify the event at level 1 on the 7-level International Nuclear Event Scale.

(1) Waste containing alpha emitters is decontaminated in the Centralized Alpha Waste Treatment Unit to reduce its radiotoxicity and allow it to be sent to surface disposal.