NUCLEAR REACTOR

Nuclear power, or Nuclear energy, is the use of exothermic nuclear processes, to generate useful heat and electricity. A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for generating electricity and in propulsion of ships. 

Nuclear Power Reactors

There are many different types of power reactors. What is common to them all is that they produce thermal energy that can be used for its own sake or converted into mechanical energy and ultimately, in the vast majority of cases, into electrical energy.

In these reactors, the fission of heavy atomic nuclei, the most common of which is uranium-235, produces heat that is transferred to a fluid which acts as a coolant. During the fission process, bond energy is released and this first becomes noticeable as the kinetic energy of the fission products generated and that of the neutrons being released. Since these particles undergo intense deceleration in the solid nuclear fuel, the kinetic energy turns into heat energy.

In the case of reactors designed to generate electricity, to which the explanations below will now be restricted, the heated fluid can be gas, water or a liquid metal. The heat stored by the fluid is then used either directly (in the case of gas) or indirectly (in the case of water and liquid metals) to generate steam. The heated gas or the steam is then fed into a turbine driving an alternator.

Since, according to the laws of nature, heat cannot fully be converted into another form of energy, some of the heat is residual and is released into the environment. Releasing is either direct – e.g. into a river – or indirect, into the atmosphere via cooling towers. This practice is common to all thermal plants and is by no means limited to nuclear reactors which are only one type of thermal plant.

Kudankulam Nuclear Power Plant is a nuclear power station in Koodankulam in the Tirunelveli district of the southern Indian state of Tamil Nadu. Construction started March 2002 but the plant missed several deadlines since it was originally scheduled for December 2011. Long construction times for nuclear reactors are common in India,^[1] but this delay is by some people believed to have been caused by the 500-day long anti-nuclear protests by the locals, led by the People's Movement Against Nuclear Energy. The first reactor of the plant, which is also India's first 1,000MW pressurised water reactor, attained criticality on 13 July 2013 at 11.05pm IST. The plant was commissioned six years after the scheduled date

India's 21st nuclear reactor at Kudankulam in Tamil Nadu is functioning well after it began nuclear fission process for the first time Saturday night, a senior official said Sunday.India's atomic power plant operator, NPCIL, is setting up two 1,000 MW reactors with Russian technology and equipment at Kudankulam, around 650 km from Chennai.The over Rs17,000 crore project, which came up in the face of intense protests in nearby villages who feared for their safety, began generating heat and steam from the 163 uranium fuel bundles loaded in the reactor.The reactor was loaded with fuel assemblies containing about 80 tonnes of uranium oxide.On July 11 night, armed with the AERB's clearance, the KNPP started its journey towards criticality.According to officials, several low power tests will be carried out in order to verify the conformance of the reactor characteristics to design objectives.If the reports are satisfactory, the AERB will give its clearance for the next stage, which is phase-wise increase in reactor power level. At the first stage, the plant will be synchronised with the southern grid when power generation touches 400 MW. That is expected to happen in 30-45 days.After necessary regulatory clearances, power generation will be increased gradually to 50 percent, 75 percent, 90 percent and finally 100 percent.When that happens, the total installed nuclear power capacity in the country will go up to 5,780 MW.KNPP is India's first pressurised water reactor belonging to the light water reactor category.While the power from KNPP will be shared by the southern states, the lion's share will be for the home state Tamil Nadu, which is suffering from power deficit."Tamil Nadu's share of the 1,000 MW will be 463 MW. As and when the power comes to our grid, it will certainly ease the power shortage to some extent," a senior official at Tamil Nadu Generation and Distribution Corporation Ltd (TANGEDCO) said."The utility sources power from various central power generating units at varied rates but less than Rs.3 per unit, whereas the power from KNPP will be over Rs3 per unit,".As for the second unit at KNPP, there will be time lag of six to eight months. loading of dummy fuel (dummy fuel assemblies are the exact replica of the actual nuclear fuel assemblies, both in dimension and weight but without uranium) was under progress and was expected to get over in around 10 days.It is learnt construction work for the administrative building for the next two units is progressing at the KNPP site.It was a matter of time before the general framework agreement was signed with the Russian suppliers for the third and fourth units.The total outlay for the third and fourth units would be Rs40,000 crore."The issue of liability of the suppliers in the case of an accident is one of the reasons for the delay in the signing of the agreement,".On the level of local content in the proposed two units, Sinha said it was for NPCIL and the Russian parties to decide and it would be covered in the general framework agreement.The KNPP is an outcome of the inter-governmental agreement between India and the erstwhile Soviet Union in 1988. However, construction, which began in 2001, was delayed due to non-sequential supplies of components from Russian vendors. Fearing for their safety in the wake of the nuclear accident at Fukushima in Japan in 2011, villagers in the vicinity of the plant, under the banner of People's Movement Against Nuclear Energy (PMANE), have opposed the project.City-based environmental activist G Sundarrajan had filed a case in the apex court demanding that the KNPP be scrapped.The court dismissed the case in May and laid down 15 directions for the NPCIL, the AERB, the central environment and forest ministry, the Tamil Nadu government and the state pollution control board.KNPP site director Sundar said the other nuclear power projects under construction are Kakrapar Atomic Power Project (2x700 MW) in Rajasthan Atomic Power Project (2x700 MW) and the second unit at KNPP of 1,000 MW.When all these come into play, the total nuclear power capacity in the country will be 9,580 MW, he said.