International Reactor Innovative and Secure - Advantages

Advantages

Most of the advantages of the new IRIS design are safety related, although Westinghouse claims that IRIS will be able to deliver power at competitive rates as well.

Due to Economies of scale, modern nuclear plants tend to be built with larger electrical outputs, such as the European Pressurized Reactor, which has scaled up power to 1600 MW in new plants. IRIS, on the other hand, is built to be used in countries where there are not extremely large electric power grids, mainly developing nations. Due to limitations on power of individual power stations versus total grid size, plants whose power is over a certain percentage of grid size are infeasible in such situations.

Due to simplifications and greater safety, it is believed by Westinghouse that in spite of its size, analysis estimated a target total cost of electricity at about 4 ¢/kWh. Given its small power and physical size, it is expected that multi-unit sites could be operated efficiently, Westinghouse estimates that a 3-unit site could be built in 9 years with a maximum cash outflow of 300 M$. One cost saver, for instance, is the need for only one control room, from which all units at a multi-unit site can be controlled.

See also: Economics of new nuclear power plants

Aside from economics, these are a few other advantages that the IRIS has:

• Fewer penetrations to the pressure vessel - by having the control rods and all drive mechanisms contained within the vessel, the need for dozens of small penetrations is eliminated, which are extremely costly. The only penetrations used are for the incoming and outgoing secondary coolant and for emergency safety systems.
• Large operating margins - the operating margins are typically the measure of a value compared to what that value would have to be to fail the fuel. IRIS effectively gets much lower operating margins by having a core with a much lower power density, while the core is mostly the same size as a current PWR, the thermal output is much smaller, making it much less likely to reach film boiling and fail in an accident.
• Lower radiation doses to workers - due to the confinement of all the RCS components and more shielding (by a larger water mass) result in low estimated doses for plant workers than current designs.
• Collaboration and research - incorporating so many universities and labs into the project is expected to have a number of benefits, one is contributing to the academic knowledge available for new plants, another is that researchers in many diverse countries with experience regarding the IRIS will be useful when they are deployed, because a goal of the project is to eventually build plants in countries that do not currently have nuclear plants.
• Lowered core damage frequency (CDF) - as a result of all the individual innovations that improve safety and an in depth Probabilistic risk assessment study that refine the net safety risk, IRIS has the lowest CDF (which is a quantitative measure of the probability of a major core accident taking place) associated with any proposed plant of 10−8.
• Marketing and licensing - With the vastly improved safety, there should be a quick and easy licensing associated with the design, and it could occupy a large part of a growing market for small size nuclear power plants, which is also being targeted by other designs such as the Russian floating nuclear power station.