A Generation III reactor is a development of Generation II nuclear reactor designs incorporating evolutionary improvements in design developed during the lifetime of the Generation II reactor designs. These include improved fuel technology, superior thermal efficiency, significantly enhanced safety systems, and standardized designs for reduced maintenance and capital costs. The first Generation III reactor to begin operation was Kashiwazaki 6 in 1996. Due to the prolonged period of stagnation in the construction of new reactors and the continued popularity of Generation II/II+ designs in new construction, relatively few third generation reactors have been built. Generation IV designs are still in development as of 2017, and are not expected to start entering commercial operation until 2020-2030.
Overview
Though the distinction is arbitrary, the improvements in reactor technology in third generation reactors are intended to result in a longer operational life compared with currently used Generation II reactors. The core damage frequencies for these reactors are designed to be lower than for Generation II reactors – 60 core damage events for the EPR and 3 core damage events for the ESBWR per 100 million reactor-years are significantly lower than the 1,000 core damage events per 100 million reactor-years for BWR/4 Generation II reactors. The third generation EPR reactor was also designed to use uranium more efficiently than older Generation II reactors, using approximately 17% less uranium per unit of electricity generated than these older reactor technologies. An independent analysis conducted by environmental scientistBarry Brook on the greater efficiency and therefore lower material needs of Gen III reactors, corroborates this finding.
Response and criticism
Proponents of nuclear power and some who have historically been critical have acknowledged that third generation reactors as a whole are safer than older reactors. Edwin Lyman, a senior staff scientist at the Union of Concerned Scientists, has challenged specific cost-saving design choices made for two Generation III reactors, both the AP1000 and ESBWR. Lyman, John Ma, and Arnold Gundersen are concerned about what they perceive as weaknesses in the steel containment vessel and the concrete shield building around the AP1000 in that its containment vessel does not have sufficient safety margins in the event of a direct airplane strike. Other engineers do not agree with these concerns, and claim the containment building is more than sufficient in safety margins and factors of safety. The Union of Concerned Scientists in 2008 referred to the EPR as the only new reactor design under consideration in the United States that "...appears to have the potential to be significantly safer and more secure against attack than today's reactors." There have also been issues in fabricating the precision parts necessary to maintain safe operation of these reactors, with cost overruns, broken parts, and extremely fine steel tolerances causing issues with new reactors under construction in France at the Flamanville Nuclear Power Plant.
Existing and future reactors
The first Generation III reactors were built in Japan, in the form of Advanced Boiling Water Reactors. In 2016 a Generation III+ VVER-1200/392M reactor became operational at Novovoronezh Nuclear Power Plant II in Russia, which was the first operational Generation III+ reactor. Several other Generation III+ reactors are under late-stage construction in Europe, China, India, and the United States. The next Generation III+ reactor to come online is a Westinghouse AP1000 reactor, the Sanmen Nuclear Power Station in China, which was scheduled to become operational in 2015. It has been completed and achieved criticality on June 21, 2018, and entered into commercial operation on September 21, 2018. In the United States, reactor designs are certified by the Nuclear Regulatory Commission. the commission has approved five designs, and is considering another five designs as well.
Generation III reactors
Generation III reactors currently operational or under construction
Generation III designs not adopted or built yet
Generation III+ reactors
Generation III+ designs offer significant improvements in safety and economics over Generation III advanced reactor designs. Unit 3 and 4 under construction. India's first Generation III+ reactor.
Generation III+ reactors currently operational or under construction
