The downstream exit aperture of the JET Neutral Beam Injector Box defines the edge of the profile of each beam as it enters the drift-duct region. This aperture is fitted with a Box Scraper assembly comprising high heat-flux hypervapotron elements mounted in a picture-frame arrangement in order to intercept the peripheral part of the beam profile, representing up to 20% of the transmitted power. In order to cope with the enhanced power resulting from upgrading the Neutral Beam Injection Systems at the JET Facility, in which the deuterium neutral beam power from a single box has been increased from 7.5MW to 15MW, it has been necessary to re-design the Box Scraper assembly completely. The design has utilised the original JET hypervapotron concept for the heat flux components, but the internal geometry has been further optimised in order to achieve an increase of peak power density to 13 MWm-2 at the hypervapotron element's surface. Comparisons between the old and new designs with regard to geometry, front surface operating temperature and cooling water velocity are presented. Design constraints of the Box Scraper assembly due to the limitations imposed by the available space envelope within the Injector system are discussed. The adopted design has an optimised arrangement of a pair of hypervapotron elements side by side inclined at different angles of attack to match the gradient of the power density at the beam edge, giving a design figure of 400kW power handling per beam. This satisfies the further power increase. The paper also describes the first operational experience with the new Box Scraper on the JET beamlines and results of the power handling tests carried out on the new Box Scraper prototype assembly at JET Neutral Beam Test Bed operated with new high power 130kV/60A Positive Ion Neutral Injectors. Finally, the problems of installing such an assembly into a tritiated neutral beam system and the methodology adopted are reviewed.