May 16 Last rig is removed from DR 3

On 15 May, DD celebrate that an internal milestone was crossed when the last rig was selected by DR 3. It was a historic day for the technical crew, who were riding the lead-lined horizontal transport bottle for the last time.

T Tuesday, May 15, was one of the days when DD had something to celebrate on the internal lines. DR 3 reached the very goal of removing rigs (pipes) from the reactor when the last irradiation tube from horizontal silicon was pulled out of the the research reactor .

Just a few years ago, the reactor was surrounded by a host of auxiliary systems such as ventilation and cooling systems, and remnants from experimental setups such as the silicon dotering plant. Since the characterisation (hedging of radioactivity levels, etc.) of the reactor in 2003, rigs have also been stored in the horizontal and vertical test holes of the reactor. Over the past few years, pipes, systems and equipment have been removed one by one of the DD 's research technicians and experimental assistants, and the reactor is now left quite naked.

The rigs are radioactive as they have been exposed to radiation during operation. The set-aside is therefore carried out, inter alia, by means of a transport bottle which is lined with lead and which effectively shields the environment from radiation.

The removal is a rather complicated affair, partly because the 23.8-ton large lead bottle has to be manoeuvred into place in a cramped environment with the hall's large polar crane, and partly because the operation of fitting the "bridge" between reactor and bottle and of the bottle itself must be done quickly and precisely so that employees are not exposed to unnecessary radiation.

Fortunately, know DD 'Technical staff worked back from operating time, where both the vertical and horizontal transport bottle were more often used to move equipment, fuel and test tubes. However, this operation was the last time the horizontal bottle is put into service at the facility, and today's successful operation was also a historic day for the technical staff. The bottle containing the last rig was shipped out of DR 3 with a safe hand and into the AH hall, where the rig is so far stored in a concrete-lined storage hole.

The next steps in the dismantling of DR 3 are the dismantling of the heavy water space, which will begin in June 2012. In addition, the top void on top of the reactor must be cleared to masterplan, so that it is ready for the dismantling of the internal parts of the reactor.