  A significant functional upgrade is planned for the Mega Ampere Spherical
Tokamak (MAST) device, located at Culham in the UK, including the
implementation of a notably greater neutral beam injection power. This upgrade
will cause the emission of a substantially increased intensity of neutron
radiation for a substantially increased amount of time upon operation of the
device. Existing shielding and activation precautions are shown to prove
insufficient in some regards, and recommendations for improvements are made,
including the following areas: shielding doors to MAST shielded facility
enclosure (known as "the blockhouse"); north access tunnel; blockhouse roof;
west cabling duct. In addition, some specific neutronic dose rate questions are
addressed and answered; those discussed here relate to shielding penetrations
and dose rate reflected from the air above the device ("skyshine").
