International Reactor Innovative and Secure (IRIS) is a Generation IV reactor design made by an international team of companies, laboratories, and universities and coordinated by Westinghouse. IRIS is hoped to open up new markets for nuclear power and make a bridge from Generation III reactor to Generation IV reactor technology. The design is not yet specific to reactor power output. Notably, a 335 MW output has been proposed, but it could be tweaked to be as low as a 100 MW unit. IRIS is a smaller-scale design for a Pressurized water reactor (PWR) with an integral reactor coolant system layout, meaning the steam generators, pressurizer, control rod drive mechanisms, and reactor coolant pumps are all located within the reactor pressure vessel. This causes it to have a larger pressure vessel than an ordinary PWR despite a lower power rating, the size is more comparable to that of an ABWR. Many of these design goals coincide with the objectives of the GNEP program launched by the Bush Administration. With large international acceptance, IRIS could be a very large part of GNEP, providing a plant type for user nations. (en)