BNFL Environmental Services has completed the demolition of the Scottish Universities' Research Reactor (SURR) at the former National Engineering Laboratory near Glasgow.
The company won the contract to demolish the 300kWe nuclear research reactor owned by Glasgow, Edinburgh and Strathclyde universities in April 1999. After the initial design and planning stage, the team began work on site in January 2000 to demolish the reactor, dispose of the waste and clean up the site.
The BNFL Environmental Services team built a containment tent around the reactor to stop the spread of contaminated waste, and included a purpose-designed ventilation system. To ensure dose minimisation, most of the work on the reactor was carried out remotely using a hydraulically operated vehicle with a variety of cutting and excavating attachments.
The radioactivity in the reactor's concrete surround also provided the team with additional challenges. Tom McCool, project manager for BNFL Environmental Services, said: "Around the graphite core was a 3m concrete wall, some of which was activated. We took core samples and, from the information obtained, calculated the depth of the activity and hence how much of the concrete would be classified as free release. We were then able to remove 200t of concrete as free release. However, from sampling the concrete, we discovered quantities of tritium which causes difficulties due to its mobility and the difficulty of detection. We had to develop novel methods of identifying tritium in the concrete. Working in conjunction with the university, we developed a method of sampling which produced results within just a few days." In addition, when breaking out free release concrete, one of the things that the BNFL Environmental Services team became aware of was the amount of dust being created that limited visibility. Traditional water sprays were not effective in killing the dust, so the team developed a vacuum system that they attached behind the breaker, which removed in excess of 80% of the dust.