  The European Spallation Source ESS is being constructed in Lund, Sweden, to
be the world's brightest cold pulsed spallation neutron source. The facility
uses a 2GeV proton beam hitting a target to produce neutrons. The neutrons are
then thermalized in a moderator. Surrounding the moderator are several beam
ports connected to neutron guides that transport the cold neutrons. Due to the
long-pulse source nature of the ESS, neutron scattering instruments are
significantly longer than at most existing facilities, with approximately half
the instruments requiring neutron guides that are 150 meters long and only a
few shorter than 50 meters. Therefore the shielding cost is dominated by the
guide shielding. To fulfill the shielding requirement, a 'Common Shielding
Project' has been initiated to deliver cost-effective and standardized
solutions for several instruments. This includes both a consistent design of
the shielding blocks, as well as a common approach to neutronics simulations.
