The URD presents a clear and comprehensive set of utility requirements for the next generation of nuclear power plants using LWRs in the USA. It was developed in the USA with the management and coordination of the Electric Power Research Institute (EPRI) and under the leadership of a group of American nuclear utilities. Some international utilities also took part in the development effort.

The URD consists of four volumes: [106]

• Volume II presents a complete set of both top-tier and detail require­ments for evolutionary-type advanced light water reactors (ALWRs).

• Volume III provides a comprehensive set of top-tier and detail require­ments for passive-type ALWRs.

The above Volumes II (Evolutionary ALWRs) and III (Passive ALWRs) each contain 13 chapters, as follows: (1) Overall requirements, defining common requirements applicable to a number of plant systems; (2) Power generation systems; (3) Reactor coolant system and reactor non-safety auxiliary systems; (4) Reactor systems; (5) Engineered safety systems; (6) Building design and arrangement; (7) Fuelling and refuelling; (8) Plant cooling water systems; (9) Site support systems; (10) Man-machine interface systems; (11) Electric power systems; (12) Radioactive waste processing systems; and (13) Turbine-generator systems.