The Nuclear Decommissioning Authority

Winfrith's DRAGON loses its fire

06 October 2008

 

It looks like a giant old fashioned cylindrical bread bin but this one built in 1964 at Winfrith in Dorset housed a 20 mega watt High Temperature Nuclear Reactor built under the sponsorship of the organisation for Economic Co-operation and Development (OECD).

Called DRAGON, it was originally destined to operate for five years but continued for a total of 17 years closing in 1976 when the 26 meter high, 35.5 meter in diameter facility went into a period of care and maintenance.

Then in July 2005 a programme to accelerate its decommissioning got underway.

The contract for the work was awarded to Costain Nuclear and it covered the removal of all redundant equipment in the inner and outer containment and non-containment areas; decontamination to low levels and the treatment of wastes. A major part of the work included replacing the original polar crane at the top of the building with a much lighter 25 tonne unit.

Everything was stripped out except for the carousel used for fuel assembly, the Reactor Pressure Vessel, helium clean-up plant and the charge machine, leaving space for work on Phase 2 of the project.

This final phase has now been deferred for 20 years because of funding limits however work on refurbishing a weather shield roof has continued.

Karl Shuler, Project Manager for DRAGON said:
“The building will be left with new ventilation and electrical systems. All of the fuel is gone so it will be in superb condition for the next phase in 20 years time”

When that time comes a cell will be built on top of the Reactor Pressure Vessel and it will be removed from within and packaged as Intermediate Level Waste.

“DRAGON is now virtually empty. We have removed tonnes of equipment and miles of electrical cables from what was a very confined space. These materials were among the first in the UK to be shipped as Very Low Level Waste. We have made photographic records of the interior to remind us of how congested it was and where things were located to help the final phase of the job,” Karl said.