Provision of Steel Chevrons

Descriptions

The Central Laser facility (CLF), part of UKRI's Science and Technology Facilities Council, is investigating the use of steel shielding bricks for a specialised radiation shielding application as a potential replacement for lead shielding blocks.

To be a consideration, we would need to be able to purchase a large quantity of steel chevron blocks, comparable in design and tolerancing to that of readily available lead chevrons. As such we would be looking for blocks that meet or exceed the mechanical requirements of BS 4513:1969 (Specification for lead bricks for radiation shielding), type V. This includes a linear tolerances of ±0.2mm. Any production method that can meet these requirements would be considered.

While special bricks will be required for wall edging most of the bricks will need to be "Plain Bricks" measuring 50x100x150 (BS 4513: V50/7, extended 50mm in breadth). As such solely production of these bricks will be considered in this PMEN.

Any Iron based alloy would be acceptable so long as its density meets or exceeds 7.85 tonne/m³. The bricks would need to be coated to prevent rust formation, any coating must be considered so as the finished block does not deviate from the mechanical requirements of BS 4513.

To be considered as a potential alternative for the lead shielding, the cost of manufacture would need to be below or equal to that of the lead shielding (on a weight for weight basis). Total quantity required would be around 88.5 tonne, for around 15,000 blocks.

We would therefore require costs to be under £330,000 (£3,750/tonne, £22 per block). If delivery is to be in a single stage, blocks would be required by the end of March 2026. However, we would be interested in a staged delivery process as this would allow installation and manufacture to run concurrently, minimising storage requirements for both CLF and supplier.