Dounreay Site Restoration Ltd

Background

The client is Dounreay Site Restoration Limited, with whom we’ve been working for more than 5 years on various aspects of the remote handling systems required to clear the D3200 shaft and silo. Against strong international competition we won the design, build and installation contact for the Shaft Intervention Platform. This contract runs for 3 years and covers development of the shaft intervention platform, its deployment system from the maintenance bay and all remote task equipment and tooling.

Objectives

  • Specify, design and build the shaft intervention platform.

  • Our involvement is just one element in the on-going decommissioning of the Dounreay site. Our unique experience of remote handling operations in hostile environments informed the specification and sourcing of suitable COTS equipment to provide a cost effective solution.

  • We facilitate off-site testing wherever possible to minimise installation, commissioning, and decommissioning timeframes.

Challenges

Hostile radioactive conditions

The conditions necessitate systems that are fully remotely controlled, and demand equipment that can withstand the hostile environment for the duration of the decommissioning process.

Keeping costs down

Specifying and sourcing COTS equipment was our first step towards keeping costs low. The solution we have developed deploys off-the-shelf elements adapted and altered especially for this application.

Water levels

The level of water within the shaft will change as the waste is removed as the differential pressure between the water table and the shaft water level changes. Controlling the water level in the shaft will be essential during operation of the Shaft Intervention Platform

Increasing depth

Maintaining a steady source of hydraulic and electrical power will become more challenging the deeper the retrieval point recedes. This will also affect the lights, cameras and monitoring equipment that facilitate the precision of remote handling applications.

Solution

The Dounreay Shaft and Stub decommissioning project is unlike anything undertaken in the UK before, and possibly the world. It requires a unique solution with fit for purpose remote handling technology and innovative engineering at heart. Our solution capitalises on the value of available equipment and then adapts it to be fit for purpose in hostile, unprecedented circumstances.

Outcome

A highly optimised and engineered solution that meets all the clients requirements while reducing the full life-cycle decommissioning costs.