China aprueba proyecto piloto de energía nuclear
El gobierno de China aprobó hoy la construcción de unidades piloto de energía nuclear que usen la tecnología "Hualong Uno", un diseño de reactor de tercera generación desarrollado nacionalmente.
BEIJING, 15 abr (Xinhua) -- "Hualong Uno" se desarrollará a partir de la experiencia de más de 20 años de los operadores de energía nuclear de China y sigue la filosofía de diseño líder mundial, señala un comunicado emitido luego de una reunión ejecutiva del Consejo de Estado presidida por el primer ministro Li Keqiang.
La aprobación se ajusta a las tendencias de energía globales y ayudará a optimizar la estructura de energía del país y a construir un sistema de energía limpia diversificado, agrega el comunicado.
La tecnología de reactor "Hualong Uno" fue diseñada de manera conjunta por dos gigantes de la energía nuclear: Grupo General de Energía Nuclear de China y la Corporación Nacional Nuclear de China. La tecnología pasó las pruebas de inspección de un panel nacional de expertos en agosto de 2014.
En noviembre de 2014, la Administración Nacional de Energía aprobó el uso de la tecnología "Hualong Uno" para construir dos reactores en la provincia de Fujian, sureste de China.
Utilizar tecnología nacional ayudará a elevar la competitividad de la industria manufacturera de equipo de China, a promover la inversión efectiva y a contribuir a la modernización industrial y al crecimiento económico estable, agrega el comunicado.
"Al implementar el proyecto piloto, China debe adoptar los estándares de seguridad más elevados del mundo y mejorar los planes de contingencia y las medidas de respuesta de emergencia para garantizar la construcción y operación seguras", menciona el documento.
El proyecto ayudará a producir equipo y tecnologías clave, y allanará el camino para que el equipo nuclear de China entre en el mercado mundial, indica el comunicado.
La reunión también estableció los requisitos para la reestructuración económica en múltiples áreas, que incluyen la modernización de la administración y la delegación de poderes a niveles inferiores, así como a los sectores fiscal y financiero y agrícola.
El país debe continuar eliminando las aprobaciones administrativas, dar prioridad a las medidas que puedan
estimular al mercado y aprovechar al máximo el papel del mercado a través de las reformas, agrega el comunicado.
Hualong No.1 is expected to be constructed by the end of 2020
Chinese nuclear power industry usher its sixty birthday. According to the reporter, the third-generation nuclear power technology with intellectual property rights, will respectively be born at home and abroad and is planned to be constructed by the end of 2020. Chinese nuclear power going overseas has achieved great breakthrough since then.
(Updated December 2014)
- Improved designs of nuclear power reactors are constantly being developed internationally.
- The first so-called 3rd generation advanced reactors have been operating in Japan since 1996. These have now evolved further.
- Newer advanced reactors now being built have simpler designs which reduce capital cost. They are more fuel efficient and are inherently safer.
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.
Several generations of reactors are commonly distinguished. Generation I reactors were developed in 1950-60s, and outside the UK none are still running today. Generation II reactors are typified by the present US and French fleets and most in operation elsewhere. So-called Generation III (and 3+) are the Advanced Reactors discussed in this paper, though the distinction from Generation II is arbitrary. The first are in operation in Japan and others are under construction or ready to be ordered. Generation IV designs are still on the drawing board and will not be operational before 2020 at the earliest.
About 85% of the world's nuclear electricity is generated by reactors derived from designs originally developed for naval use. These and other nuclear power units now operating have been found to be safe and reliable, but they are being superseded by better designs.
Reactor suppliers in North America, Japan, Europe, Russia and elsewhere have a dozen new nuclear reactor designs at advanced stages of planning, while others are at a research and development stage. Fourth-generation reactors are at concept stage.
So-called third-generation reactors have:
- a standardised design for each type to expedite licensing, reduce capital cost and reduce construction time,
- a simpler and more rugged design, making them easier to operate and less vulnerable to operational upsets,
- higher availability and longer operating life – typically 60 years,
- further reduced possibility of core melt accidents,*
- substantial grace period, so that following shutdown the plant requires no active intervention for (typically) 72 hours,
- resistance to serious damage that would allow radiological release from an aircraft impact,
- higher burn-up to use fuel more fully and efficiently and reduce the amount of waste,
- greater use of burnable absorbers ("poisons") to extend fuel life.
* 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. The IAEA safety target for future plants is 1x10-5. Calculated large release frequency (for radioactivity) is generally about ten times less than CDF.
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.
* Traditional reactor safety systems are 'active' in the sense that they involve electrical or mechanical operation on command. Some engineered systems operate passively, eg pressure relief valves. They function without operator control and despite any loss of auxiliary power. Both require parallel redundant systems. 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.
Another departure is that some PWR types will be designed for load-following. While most French reactors today are operated in that mode to some extent, the EPR design has better capabilities. It will be able to maintain its output at 25% and then ramp up to full output at a rate of 2.5% of rated power per minute up to 60% output and at 5% of rated output per minute up to full rated power. This means that potentially the unit can change its output from 25% to 100% in less than 30 minutes, though this may be at some expense of wear and tear.
A feature of some new designs is modular construction. The means that many small components are assembled in a factory environment (offsite or onsite) into structural modules weighing up to 1000 tonnes, and these can be hoisted into place. Construction is speeded up.
Many are larger than predecessors. Increasingly they involve international collaboration.
However, certification of designs is on a national basis, and is safety-based – see section below.
Another feature of some new designs is modular construction. Large structural and mechanical sections of the plant of up to 1000 tonnes each are manufactured in factories or on site adjacent to the plant and lifted into place, potentially speeding construction considerably.
A contrast between the 1188 MWe Westinghouse reactor at Sizewell B in the UK and the modern AP1000 of similar-power illustrates the evolution from 1970-80 types. First, the AP1000 footprint is very much smaller – about one-quarter the size, secondly the concrete and steel requirements are lower by a factor of five*, and thirdly it has modular construction. A single unit will have 149 structural modules broadly of five kinds, and 198 mechanical modules of four kinds: equipment, piping & valve, commodity, and standard service modules. These comprise one-third of all construction and can be built offsite in parallel with the onsite construction.
*Sizewell B: 520,000 m3 concrete (438 m3/MWe), 65,000 t rebar (55 t/MWe);
AP1000: <100,000 m3 concrete (90 m3/MWe, <12,000 t rebar (11 t/MWe).
At Sanmen in China, where the first AP1000 units are under construction, the first module lifted into place weighed 840 tonnes. More than 50 other modules used in the reactors' construction weigh more than 100 tonnes, while 18 weigh in excess of 500 tonnes.