Jan 14 2014 in Review

Danish Decommissioning has had an eventful year, and our three major decommissioning projects have advanced significantly. Join us for a review of 2014.

TThe three facilities we have been decommissioning are the DR3 reactor, the Fuel fabrication plant, and the Hot Cells. DR3 (Danish Reactor 3) was Denmark's largest research reactor, operating from 1960-2000. The Fuel fabrication plant housed the production of fuel rods for the DR3 reactor. Hot Cells were concrete cells used for research on irradiated materials and the production of sources for medical use.

DR3
In DR3, we have carried out two major lifting operations, removing the reactor plug and the top ring, which were wedged into the reactor block. The plug, also known as the top shield plug or TSP, constituted 22 tons of shielding and was highly radioactive on its underside after many years of reactor operation. When it was removed, we simultaneously placed a shielding lid over the tank.

Following the TSP lift in May, we had to commence milling concrete from the lower section of the reactor block to create space for maneuvering out the wide top shield ring (TSR).

Approximately 20 cm of concrete was milled from the facade at a height of 3.30 meters. In October, the TSR was subsequently lifted out of the reactor and placed onto a specialized transport vehicle, which conveyed it out of the reactor hall.

the Fuel fabrication plant
the Fuel fabrication plant has been thoroughly decontaminated, and we are very close to completion. The building comprises several rooms where various stages of fuel rod production were carried out.

A significant portion of the work in the Fuel fabrication plant has resembled general dirty renovation. We have removed tables, sinks, pipes, and flooring, and we have abraded walls and ceilings to ensure no traces of uranium remained. The powder room was where Risø's laboratory technicians weighed out uranium in powder form and pressed it into solid pellets encased in aluminum. It was inevitable that some powder would become airborne and settle as dust.

The task involving the Fuel fabrication plant is protracted because uranium contamination in the areas has proven to be more widespread than anticipated. Our extensive measurements ensure that all contamination is removed.

Hot Cells
The Hot Cells project has involved significant planning years, as we face the challenging task of decontaminating the concrete cells through a 1.7-meter-thick wall. This entails inserting mechanical arms through openings in the wall and sandblasting the cells in all corners, including beneath the fixed table in each cell. During 2014, we developed a vacuum arm and a sandblasting arm and prepared for the modification of the ventilation system. The actual work on ventilation modification and subsequent rough decontamination will commence in 2015.

Waste management
DD is responsible for the management of Danish radioactive waste; both what we ourselves produce in connection with decommissioning, and waste from external customers. We have completed a number of special tasks during the year and we have, among other things, picked up an old blood irradiation facility from a major hospital. The plant was from 1968 and it weighed 1.2 tons. A DD -driver and a health assistant was in charge of the pick-up, which took place as a special transport. We have also contributed to the Ministry of Health's work on a long-term solution for radioactive waste. Shortly, we will be submitting contributions to a decision-making basis for long-term intermediate stocks.

DD makes a significant effort to minimize the volume of radioactive waste. In 2014, we released 35 tons of construction waste from our demolition work. Furthermore, we are working on a solution to melt or incinerate portions of the waste. The objective is to separate radioactive components and reduce the overall waste volume.

International Cooperation
DD participates extensively in international cooperation concerning decommissioning, waste management, and radiation protection. In 2014, we contributed to an IAEA project aimed at compiling experiences in radiation protection related to the decommissioning of nuclear facilities.

Furthermore, we have secured a representative on the UN's review panel for radioactive waste. This marks only the second occasion that a Dane has been appointed as an officer to a Joint Convention panel.

DD also participates in other international forums. In 2014, we were admitted to TAG (Technical Advisory Board), a network for technical knowledge workers, meaning it is non-commercial and not for authorities. We have attended numerous conferences and study visits abroad, and we have hosted visits from, among others, our sister reactor HIFAR in Australia, the Finnish radiation protection authorities, and Stilleger, an association of companies working on decommissioning in German-speaking countries. DD also engages in extensive international cooperation in the waste sector, for instance, the ERDO working group, which, among other things, investigates the possibility of a regional repository for long-lived waste.

A more detailed description of our activities can be found in the annual reports under Publications.