JET first wall and divertor protection system

WALLS has been used in Joint European Torus (JET) plasma operations as a real-time active protection system supporting the plasma shape controller. Provided with real time information on the boundary location, plasma current and the additional input power, the code checks the distance of the plasma from the wall and then computes an energy state for a set of chosen locations of the plasma facing components. If this energy function exceeds a pre-set threshold then the pulse is promptly terminated. The JET divertor MKIIGB has recently been modified (MKIISRP) by replacing the septum with a tile that has very little power handling. This paper will principally focus on the code upgrade for the new divertor.