Patent ID: 7713357

Claim:
A method for treating a radioactive surface with a treatment gel, said method comprising in this order the following steps: applying a treatment gel on the radioactive surface to be treated in an amount from 100 to 2,000 g/m 2 , said treatment gel comprising a colloidal solution comprising: 5 to 25% by weight, based on the weight of the gel, of a mixture of pyrogenated silica and precipitated silica, the pyrogenated silica representing 8% by weight of the gel, the precipitated silica representing 0.5% to 1% weight of the gel, 0.5 to 4 mol/l of an active treatment agent, wherein the active treatment agent is selected from a group consisting of acids, bases, and mixtures thereof, and optionally from 0.05 to 1 mol/l of an oxidizing agent having a normal oxidation-reduction potential (E 0 ) larger than 1.4 V in a strong acid medium or of the reduced form of this oxidizing agent, maintaining the treatment gel on the radioactive surface to be treated at a drying temperature and relative humidity such that when the gel dries it forms a dry and solid residue in the form of particles that are 0.1 to 3 mm in size, and removing, by brushing and/or suction, the dry and solid residue from the treated radioactive surface.