This is the first NPP in the world where the post-Fukushima safety enhancement requirements have been implemented. Besides, the reactor building can withstand an aircraft crash
One of the biggest take aways from Prime Minister Narendra Modi’s meeting with Russian President Vladimir Putin in St Petersburg recently was the signing of agreement for construction of the third stage of the Kudankulam Nuclear Power Plants (NPP) — Units V and VI. Civil nuclear cooperation remains an important aspect of India-Russia relationship and the Kudankulam NPP is flagship of the economic cooperation between the two countries. The agreement for construction of two new units once again confirms commitment of the two nations for further development of their economic cooperation. Russia will be constructing at least 12 power units in India.
Implemented with technical assistance from Russia — the general contractor is Atomstroyexport JSC, a subsidiary of the Russian State Atomic Energy Corporation (ROSATOM) — along with Nuclear Power Corporation of India Limited (NPCIL), the project envisages six Russian-designed power units with the safest light water reactor plants each of 1,000 MWt capacity. Unit I and II are already operational and construction work has begun on Units III and IV sites.
The importance of such large-scale project as Kudankulam NPP, located in Tamil-Nadu, for a dynamically growing Indian economy, is well recognised. Two power units of 1,000MWt capacity each with the reactor plant of VVER-1,000 type have already been supplying electricity to the Indian national grid and they are expected to significantly improve power supply in the south region. The NPP has already generated more than 13 million units of electricity and the turbogenerator was operated for more than 10,000 hours. Thus, the installed capacity of the Indian NPPs reached 6,780 MWt. The electricity tariff for the power generated by Kudankulam NPP is one of the most efficient rates in India, ie Rs4.10. Besides, it has created new working places for the Indian engineers and local personnel.
Since nuclear plants are always away from public glare, very few know about the Kudankulam NPP and its safety standards. Both NPCIL and ROSATOM have claimed that Kudankulam NPP is one of the safest plants in the world and it could have survived a Fukushima-like situation where in 2011 an earthquake followed by tsunami triggered one of the major nuclear disasters in recent years. However, geologists and environmentalist from time to time have raised concerns on the impact of the NPP in the region, particularly its safety from tsunami and volcanic eruptions and its effect on marine life.
To allay concerns, NPCIL and ROSATOM have asserted, the Kudankulam NPP belongs to the group of advanced light water reactors of the third-plus generation and today its two operating units are of the highest safety standards. It is protected against earthquake, tsunami, tornado, hurricanes and other natural calamities and explosion. It is claimed that the reactor building can even withstand an aircraft crash. In fact, this is the first NPP in the world where post-Fukushima safety enhancement requirements have already been implemented and are being operated successfully. Besides, the plant can withstand any anticipated operational occurrences and human mistake factor.
According to ROSATOM, after the accident at Fukushima NPP, in 2011 all Russian NPPs underwent preliminary stress tests which involved Rostechnadzor inspectors, general public, international experts including those from the International Atomic Eenergy Agency and all inspections confirmed that Russian NPPs are safe. Prior to that, a team of World Association of Nuclear Operators visited the Kudankulam NPP site to study its safety features.
The essential feature of these Russian-designed power units is the availability of the most up-to-date diagnostic systems. These systems enable the NPP staff to operate in prevention mode — to react on the symptoms of deviations and to prevent any failure. The principal attribute of the design is implementation of the number of engineering solutions based on the “passive” principles in addition to conventional active safety systems.
According to the generally adopted criterion, such engineering solutions bring the project close at maximum to the parameters of the fourth generation projects in respect to its nuclear safety.
A four-barrier system is created between fuel and environment to prevent ionising radiation and radioactivity release — fuel matrix prevents fission product release under fuel cladding; Fuel cladding prevents fission product release into primary (main circulation circuit) coolant; main circulation circuit prevents fission product release into containment; containment system prevents fission product release into environment.
Besides, there are a number of advanced active and passive safety systems which ensure unprecedented design level of nuclear and ecological safety of the NPP. Double localising and protecting containment, passive heat removal system from reactor plant, core catcher, and closed industrial water intake for NPP are some of them. The plant is such made that during the anticipated operational occurrences, the passive heat removal system ensures cooling of the steam generator in automatic mode and where human participation is not required. This system does not require the energy supply.
NPP reactors are equipped with the core catchers which are provided with absorbing elements. This, in case of anticipated operational occurrences, prevents penetration of the core melting into the ground and environment. The industrial cooling seawater intake protected NPP against tsunami impact in 2004. This hydro technical structure serves as a cooling industrial seawater intake.
All points of the plant are located at the proper sea water level to avoid flood and black out. In fact, an analysis was conducted for the possibility of NPP to withstand the conditions similar to what happened at Fukushima and it was found that Kudankulam NPP is equipped with sufficient passive systems ensuring core cooling as well as restriction of radiation exposure even in case of long-term black out of electricity sources and failure of the water supply systems provided in the design. Another interesting aspect of the Kudankulam NPP project is that great care has been taken to preserve the biological diversity and reach local flora and fauna of the Mannar Bay. NPP cooling sea water intake structures are equipped with the special fish protecting facilities which preserve not only fish but also fish food — plankton.
The plant does not use any of the natural sources of the desalinated water. In view of the climatic conditions of the region and requirements of the developed agricultural sector, Kundakulam NPP project envisages sea water desalination plant which ensures all plant auxiliary loads.
The positive results achieved during the construction and operation of Kudankulam NPP gives Russians a strong background for further expanding and strengthening long-term, ‘time-tested cooperation’. The two sides are already successfully collaborating in scientific and technical sphere, in nuclear fuel cycle and localisation.
Besides, new areas are being identified for cooperation between Indian companies and the enterprises of ROSATOM for non energy application of nuclear power in production of mass-market products made of composite materials such as irradiation of the food products, localising production of carbon clothes in India, water treatment etc. Radiation technologies are known for destroying harmful microorganisms, bacteria and viruses in foods, and extending the shelf life of different products, including fruit, vegetables and crops.
Successful implementation of joint projects in the civil nuclear sphere has strengthened the India-Russia strategic privilege partnership and created a strong basis for its further development and more collaborations for which sky is the limit.