1. Instrument compartments in Experimental halls 1, 2 & 3 1

2. Shielding materials Boron-loaded paraffin and boron-loaded polyethylene

3. Agenda boron-loaded paraffin  Building element with boron-loaded paraffin  Fire properties of boron-loaded paraffin  Issues regarding boron-loaded paraffin  Fire load and design fires  Safety distances and fire protection cladding 3

4. Building element 4

5. Vertical flame spread test, boron-loaded paraffin 5

6. Cone calorimeter test, boron-loaded paraffin 6

7. Boron-loaded paraffin, B(OH)3 Consists of paraffin and 30% boric acid Boric acid theoretically consists of 56% boron oxide and 44 % water Melting point 65 - 75 ˚C Heat of combustion of 21 MJ/kg Heat release of 300 kW/m2 7

8. Fire load and design fire at ESS  Fire load can be installed or variable and can contribute to a design basis fire  All excess fire load should be considered as protected fire load, not to contribute to a fire  Protected fire load shall be verified by literature or experiments  Validation of protected fire load by test at SP Technical Research Institute of Sweden  30MW design fire corresponds to 100m 2 pool fire of boron-loaded paraffin or the interior floor area of an instrument compartment of 10 x 10 m that is being rebuilt. 8

9. Safety distances - Instrument compartments during construction 9

10. Fire and heat protection of building elements 10

11. Conclusion paraffin-filled building elements  Design value will be the maximum design fire of 30MW, This corresponds to a burning truck or a burning pool fire,100 m 2, of boron-loaded paraffin. This pool fire may consist of 1 m 3 boron-loaded paraffin distributed as melted material with a height of 1 cm over 100 m 2 Conclusion: the instrument compartments can only be built or rebuilt one at a time  If a sprinkler system is installed, the fire analysis present that the 30 MW fire in an instrument compartment will not reach it’s value. The fire growth will be stopped at 6 MW Conclusion: several instruments compartments can be built or rebuilt at the same time but with safety distances  Safety distances to prevent fire spread between instrument compartments  Fire protection cladding to prevent fire spread between instrument compartments 11 1 MW2 meter 6 MW5 meter 30 MW10 meter

12. Thanks for listening!