11 May A plant steams off

At the waste treatment plant, a violent hum that required earplugs has been replaced by a gentler buzz. And a chapter in Risø's history has just been closed.

S Since the founding in the 1950s of Risø nuclear station, the colossal evaporation plant hiding in the interior of the Treatment Station has cleaned large amounts of water of radioactivity. Now the plant has run its probably last ride, and a new, much smaller machine has taken its place.

Between the buildings on the Risø Peninsula runs an underground network of water pipes and tanks. Here the so-called active water is collected from, among other things, cleaning cabinets and certain sinks; the waste water that may contain radioactive substances. A tanker periodically runs the water from the tanks to a central tank on the the waste treatment plant .

For many years, the water has been distilled in a lengthy and energy-intensive process in the large plant that has required constant monitoring. The evaporated concentrate of radioactive substances has been moulded into asphalt in drums, while the purified water is discharged into Roskilde Fjord.

The volume of activities that give rise to active water is decreasing, which is why the old plant has served its purpose. After a longer testing period, a smaller mobile plant has now taken over the entire distillation task and the old plant is at a standstill.

"The new evaporation system is more efficient, uses less energy and can take care of itself," explains operations engineer Anna Warberg Larsen and continues: "At the same time, it is mobile, so when the waste treatment plant decommissioned, the plant can be moved and included in a new set-up."