Tianwan NPP (China)
Tianwan Nuclear Power Plant (TNPP) is the largest project of economic cooperation between the People’s Republic of China and the Russian Federation. The first phase of TNPP (two VVER-1000 power units) was constructed as part of an Intergovernmental Agreement on cooperation in construction of nuclear plant in the People’s Republic of China, concluded on December 18, 1992. JSC “Atomstroyexport” contract obligations included technical responsibility for the whole project, nuclear power plant design, delivery of the equipment and materials from Russia and CIS countries, delivery of fresh nuclear fuel initial loading for each unit, training of Chinese personnel, transfer of design computer codes, performance of mounting works in four main buildings of the nuclear island, performance of commissioning work on all TNPP systems, putting the nuclear plant into operation, insuring guaranteed operation of power units, delivery of spare parts.
Construction work at the site commenced in 1998. More than 150 Russian enterprises and organizations have taken part in construction of Tianwan Nuclear Power Plant. The facilities were put into operation in 2007. The two-year guarantee operation of Tianwan NPP Units 1&2 was completed on the 12th of September, 2009. All stages of construction of TNPP Units 1&2 were successfully finalized, and both power units are operated stably at the level of 1060 MW contract rated capacity. JSC “Atomstroyexport” successfully fulfilled its obligations in the period of the warranty operation of the power units. The warranty operation period has proved the trouble-free and safe operation of the plant.
On the 15-th of April the final acceptance certificates for Units 1 and 2 of Tianwan NPP were undersigned. By this fact the Chinese customer has confirmed that general contractor – “Atomstroyexport” – had qualitatively performed all the missions assigned to it in full scope. Tianwan NPP is operating with good performance indices and possesses the most state-of-the-industry and technological safety systems.
In August 2010 at Lianyungang Symposium of the participants of Tianwan NPP construction the Chinese party declared: a record on the duration of non-stop operation in the period of the first fuel cycle among the power plants operating in China has been achieved.
ABOUT THE DESIGN
The plant has been constructed to the AES-91 design. Power plants have been designed based on the experience of construction and operation of VVER-1000/320 power units. The power unit includes reactor plant with VVER-1000/428 reactor type and K-1000-60/3000 turbine type with TVV-100002Y3 generator. The power unit corresponds to the international rules on nuclear and radiation safety.
Reactor building is protected by double containment: internal hermetic containment excludes radiation emission into the environment, and external containment is intended for reactor protection from undesirable external impacts. A trap installed under the reactor shell is intended for retention and cooldown of melted core. In case of accident it is provided for melted core to fill the trap and not to destroy the foundation under the shell and reactor building. The trap has a unique technical solution with no analogs in the world NUCLEAR POWER PLANT construction practice. China has become the first country possessing such device. The design of the trap developed by the Russian engineers has been successfully examined by supervision authorities of Russia and China and has been approved by IAEA. 4-channel structure of safety systems has been implemented at the nuclear power plant, a combination of active and passive safety devices is applied, digital monitoring and control system (MCS) is operating.
The calculations show that serious accidents with damage and melting of the core are possible not more than once in 100,000 years. Probability of severe accident with radioactivity emission beyond the nuclear power plant limits – once in million years.