The Chartreuse Museum of Douai has entrusted the ARC-Nucléart center in Grenoble with two central tables of the relief map of the town of Douai for disinfection treatment. The relief plan was commissioned by Louis XIV in 1697 from the king’s engineer De Montaigu and completed in 1710 by La Devèze. It consists of 12 plates at a scale of 1/600 in plan and 1/400 in elevation. Due to its imposing size, it is a record for the ARC-Nucléart Workshop: the largest work irradiated with gamma rays in 54 years and the second relief plan, the first being that of the town of Marsal in 1988.
The Douai relief plan had benefited from an initial restoration between 1954 and 1960, then was exhibited at the Musée de la Chartreuse in unsuitable conditions, where it was infested with mold. The safety of gamma irradiation makes it an ideal method for disinfecting this work made of wood, silk and paper. “The irradiation method allows the work to be treated en masse, without contact, without heat, and without chemicals. The fungus is eliminated and will no longer grow”explains Amy Benadiba, curator of the workshop, to France 3.
The relief plan of the town of Douai.
© ARC-Nucléart
The two central tables of the relief plan will be exposed to gamma radiation, which has an ionizing and fatal effect on micro-organisms. They will be irradiated at a minimum dose of 3 kilograys (unit of measurement of the absorbed radiation dose) and will have a duration of exposure to gamma rays of at least 15 hours per model element. In order to optimize the restoration, the laboratory previously carried out 3D modeling calculations of the relief plan using RayXExpert software. These calculations make it possible to determine the intensity of the radiation and therefore the best configuration for irradiation. After restitution, the two tables of the relief plan will be restored in order to find a new exhibition space adapted to their proper conservation.
True “works of art clinic that puts science at the service of heritage”according to Amy Benadiba (on the Andra website), the ARC-Nucléart Workshops have, over time, been able to reassure heritage professionals, initially reluctant to use nuclear energy. The only one to have a gamma transmitter for heritage purposes, the workshop restores several hundred works each year. He achieved worldwide fame in 1976 with the restoration of the 3,200-year-old mummy of Ramesses II, which was irradiated with gamma rays to eliminate the larvae and fungi that threatened it.
