Magnox Ltd has begun work on the final piece of the decommissioning jigsaw at the former Steam Generating Heavy Water Reactor (SGHWR) on the Winfrith site in Dorset.
The SGHWR reactor needs to be isolated from adjacent plant and equipment so that the Magnox Ltd team can gain access to the reactor’s core and begin to safely dismantle it. This project will be completed early next year. It will involve the removal of 1.5km of stainless steel pipework.
So far, months of planning and preparation have been necessary because of the complex nature of the project. The Magnox Ltd team has rehearsed, at minimal risk, using specially created full-scale mock-ups of the plant. Lessons learnt from this practice exercise will be used when the steam risers and feeders are removed for real.
John Clarke, NDA Chief Executive, said:
It is the mission of the Nuclear Decommissioning Authority to ensure the safe and efficient clean-up of the UK’s nuclear legacy, and therefore this milestone at Winfrith is an important step forward. With a project as demanding and complex as this one, it is important to consider the options carefully. The Magnox Ltd programme team have been thorough in exploring the safest and most cost-effective approach to this project as it moves towards completion next year.
Kevin McIntyre, Reactors Programme Manager, said:
The removal of the steam risers and feeders represent the culmination of many years pre-cursor work, leading to the eventual safe removal of the reactor core, demolition of the SGHWR complex and eventually returning the land to heathland.
The steam risers and feeders were part of the system which fed water through the reactor to produce steam, which drove the turbine when the reactor was operational, and then re-circulated the condensed water.
The only water-cooled reactor ever to be built in the UK, SGHWR’s cooling towers became the Dorset’s site most recognisable landmark. Significant decommissioning progress over the last 2 years have meant that major items have already been removed from the reactor, including the heavy water circuits, cooling water circuits, pumps and pressure relief valves, thereby enabling access to the steam feeders and risers.