10-08-2012, 11:50 AM
BUDGET AND BUDGETARY CONTROL
Budget-and-Budgetary-Control.doc (Size: 2.9 MB / Downloads: 158)
Principle objective and working of nuclear power plants
Nuclear power plants generate electricity. The principle used is same as that in a thermal power plant, with the difference that a nuclear plant uses uranium to produce heat whereas a thermal power plant burns coal.
Principle
Nuclear power generation utilizes the heat energy from the atomic fission of natural uranium U-235 to produce steam. This steam in turn drives the turbo generator to produce electricity.
Objectives
• To maximize generation (2891 Mus or More) and capacity utilization (75% or more) in a safe manner.
• To minimize the number of forced outages to as low as responsible achievable.
• To minimize outage period for planned maintenance and at the same time achieving the maintenance objectives.
• Planned implementation of conditions monitoring in service inspection, modification and upgrading program in an optimal manner during planned maintenance outages.
• To minimize radioactivity release to as low as reasonably achievable.
• To minimize radiation exposures to as low as reasonably achievable.
• To minimize heavy water losses to as low as reasonably achievable.
• To progressively optimise inventory levels.
• To progressively achieving energy conservation in an efficient manner.
• To improve quality in all activities by ensuring adherence to procedures pre-jobs briefings and training/re-training of personnel.
• To treasure human resources by continuous exposure to training.
• To ensure human resources development quantitatively and qualitatively and in a sound and cordial industrial relations environment.
Working of Nuclear Power Plants
FISSION REACTION:
92U235 + ON1 = 38Sr90 + 54Xe144+ 20N1 + gamma ray
Thermal neutrons continue the chain reaction by splitting other uranium atoms releasing radioactivity, fission fragments, fast neutrons and heat energy.The energy generated by the fission is transmitted from the fuel bundle with the help of high-pressure heavy water called PHT (primary heat transport). The PHT system takes away the heat from the fuel bundles to the mineralised water into the steam generator. Here steam is generated at a pressure of 40-48 kg/cm sq. this steam is then transported through pipes to turbine hall where the turbine and generator are installed. The steam enters the turbine and runs it at a speed of 300 RPM. The generator and the turbine run at the same speed as they are coupled together. The electricity generated is sent to the station switchyard for transmission to the Northern grid.
Petroleum prices are escalating. The amount of coal required for 400Mwe power generation is of the order of 5x106 kgs per day. Whereas a nuclear power station of the same capacity needs only 200 kg of atomic fuel per day. Transportation of coal of such magnitude over long distances is not economical.
Several years ago, the DAE has selected heavy water moderated natural uranium reactors as the type with the greatest promise under Indian conditions. Reactors of this type use fuel available within the country & do not require large capital and operating outlays for fuel enrichment. With collaboration of Atomic Energy of Canada Limited (AECL), who had considerable experience in the design and operation of such reactors at the time, a research reactor CIRCUS was built which provided the required operating experience for the personnel and confidence for the management.
Nuclear power plants are considerably more expensive to build than alternative thermal plants. To be economic they must therefore operate at high capacity factor throughout their lifetime. But to command high utilization, any plant must have low operating costs. In this connection, the low fuelling cost of heavy water natural uranium reactors are of major economic importance, and are expected to result in lower operating costs that can be achieved either in conventional thermal plants or other types.
The strategy adopted for Indian nuclear power program is that heavy water power reactors using natural uranium would produce power and plutonium in the first stage. The plutonium produced from these reactors would be used to set up high breeding ratio fast reactors to produce additional power and plutonium in the second stage. In the third stage thorium would be utilized in both the fast and the thermal reactors, which would give unlimited source of power.Consequently it was decided to build twin “PHWR” (pressurized heavy water reactor) type of power reactors. The site is selected by a high-powered committee, based on the need of electrical power, the potential for industrial expansion, availability of large quantities of water and less population.
AIM, MISSION, VISION
AIM
One of the chief aim of department of atomic energy (DAE) is development of nuclear energy for economic power generation as an alternative source of electric power when in due course the conventional sources [hydro and thermal] will be exhausted in the country.
MISSION
"To develop nuclear power technology and to produce nuclear power as a safe, environmentally benign and economically viable source of electrical energy to meet the increasing electricity needs of the country."
VISION
Achieve installed capacity of 20,000 Mw by the year 2020.