WINFRITH - Detailed Design and Build of a Core Segmentation Cell and Intermediate Level Waste (ILW)

Descriptions

The Steam Generating Heavy Water Reactor (SGHWR) at Winfrith is in the final stages of decommissioning. Critical to the success of the decommissioning programme is the safe removal and segmentation of the highly activated rector core, weighing around 250 tonnes. The scheme design for the decommissioning of the reactor core involves a combination of lifting reactor core tanks and jacking the reactor core from below into a shielded segmentation cell for size reduction and sentencing into ILW boxes in an ILW Export Facility.Research Sites Restoration Limited (RSRL) requires a suitably qualified and experienced contractor (possibly in a consortium with others) to deliver a fully functioning Core Segmentation Cell and Intermediate Level Waste (ILW) Export Facility capable of meeting RSRL's requirements . The key components of the Core Segmentation Cell and ILW Export Facility are as follows:— Core Segmentation Cell - A main segmentation cell will be established above the reactor core into which core components will be raised and segmented before being transferred onto a floor mounted rail and trolley system to an auxiliary segmentation area for size reduction and packing into waste baskets.— ILW Export Facility - This is an ILW handling system to allow waste in baskets to be removed from the segmentation cell into the export cell, to be grouted into boxes.— Waste Assay System - This system will assay the ILW, record the waste basket activity and log that data against the container in which the basket is grouted.— Core Jacking System – A load-bearing thrust plate with jacking points and a jacking system will be assembled then installed below the reactor core. The system will be self levelling and self latching with built in shielding capable of raising the reactor core progressively into the segmentation cell for size reduction and packaging— Civil Modifications - Modifications to the existing structure will be required to form the core segmentation cell, ILW waste export facility and associated areas.— Electrical, Controls and Instrumentation Systems – Electrical supplies and lighting to the including the systems listed above; the provision of camera systems, a control system, and other general detection systems.— Ventilation Systems – A hazard extract and air system.The scope of the contract will include:— The detailed design of the Core Segmentation Cell and ILW Export Facility supported by optioneering studies, hazard and operability studies, calculations, and a Design Justification Review.— The design and build of full scale mock-ups of the reactor core and Core Segmentation Cell; together with the proposed equipment to allow integration, testing and development of remote handling, jacking, lifting, size reduction techniques, and to enable further cutting trials/ tooling development.— The procurement of materials, the manufacture, and the off-site testing of the Core Segmentation Cell and ILW Export Facility— The build, installation and inactive commissioning of the Core Segmentation Cell and ILW Export Facility.— Where appropriate, support for active commissioning, maintenance, repair, training, development of tooling and general operational support and warranty.The contract will include a critical milestone beyond which construction does not commence until the design and all necessary safety case documentation has been accepted by RSRL.RSRL will provide some safety management documentation including the Preliminary Safety Report. The contractor provides detailed safety documentation including method statements, risk assessments and the Pre-Commencement/ Construction Safety Report.Installation will involve working in close proximity to the reactor core and will be carried out under strict safe systems of work closely controlled by RSRL.