#PROJECTS ON POWER WORLD SIMULATOR FULL#
Inherent or full passive safety depends only on physical phenomena such as convection, gravity or resistance to high temperatures, not on functioning of engineered components, but these terms are not properly used to characterise whole reactors.Īnother departure is that most will be designed for load-following. They function without operator control and despite any loss of auxiliary power. Some engineered systems operate passively, eg pressure relief valves. * Traditional reactor safety systems are 'active' in the sense that they involve electrical or mechanical operation on command. The greatest departure from most designs now in operation is that many incorporate passive or inherent safety features* which require no active controls or operational intervention to avoid accidents in the event of malfunction, and may rely on gravity, natural convection or resistance to high temperatures. Calculated large release frequency (for radioactivity) is generally about ten times less than CDF. The IAEA safety target for future plants is 1x10 -5. * The US NRC requirement for calculated core damage frequency (CDF) is 1x10 -4, most current US plants have about 5x10 -5 and Generation III plants are about ten times better than this. Greater use of burnable absorbers ('poisons') to extend fuel life.Higher burn-up to use fuel more fully and efficiently, and reduce the amount of waste.Stronger reinforcement against aircraft impact than earlier designs, to resist radiological release.Substantial grace period, so that following shutdown the plant requires no active intervention for (typically) 72 hours.Further reduced possibility of core melt accidents.*.Higher availability and longer operating life – typically 60 years.A simpler and more rugged design, making them easier to operate and less vulnerable to operational upsets.A more standardised design for each type to expedite licensing, reduce capital cost and reduce construction time.So-called third-generation reactors have: Fourth-generation reactors are at the R&D or concept stage. Reactor suppliers in North America, Japan, Europe, Russia, China and elsewhere have a dozen new nuclear reactor designs at advanced stages of planning or under construction, while others are at a research and development stage. These and other nuclear power units now operating have been found to be safe and reliable, but they are being superseded by better designs. Over 85% of the world's nuclear electricity is generated by reactors derived from designs originally developed for naval use. Generation IV designs are still on the drawing board and will not be operational before the 2020s. The first ones are in operation in Japan and others are under construction in several countries. So-called Generation III (and III+) are the advanced reactors discussed in this paper, though the distinction from Generation II is arbitrary.
Generation II reactors are typified by the present US and French fleets and most in operation elsewhere. Generation I reactors were developed in 1950-60s, and the last one shut down in the UK in 2015. Several generations of reactors are commonly distinguished. The nuclear power industry has been developing and improving reactor technology for more than five decades and is starting to build the next generation of nuclear power reactors to fill new orders. * For smaller advanced reactors see the companion page on Small Nuclear Power Reactors. These are described in a separate information paper.*
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