purpose of fuel rods in a nuclear reactor
Nuclear fuel Uranium dioxide (UO2) powder is compacted to cylindrical pellets and sintered at high temperatures to produce ceramic nuclear fuel pellets with a high density and well defined physical properties and chemical composition. A grinding process is used to achieve a uniform cylindrical geometry with narrow tolerances. Such fuel pellets are then stacked and filled into the metallic tubes. The metal used for the tubes depends on the design of the reactor. Stainless steel was used in the past, but most reactors now use a zirconium alloy which, in addition to being highly corrosion-resistant, has low neutron absorption. The tubes containing the fuel pellets are sealed: these tubes are called fuel rods. The finished fuel rods are grouped into fuel assemblies that are used to build up the core of a power reactor.
Nuclear power in India At a meeting of the Atomic Energy Commission on 15 March 1955, the decision was made to construct a small nuclear reactor at Trombay. The reactor would be used for training personnel for the operation of future reactors and for research, including experiments in nuclear physics, studying the effects of irradiation and the production of isotopes for medical, agricultural and industrial research.[25] In October 1955, an agreement was signed by the United Kingdom Atomic Energy Authority and the Indian Department of Atomic Energy, under which Britain would supply uranium fuel elements for a pool-type reactor to be designed by India.[25] The agreement further ensured the "close cooperation and mutual assistance between the Department and the Authority in the promotion and development of the peaceful uses of atomic energy," and provided for future design and collaboration in the construction of a high flux reactor at a later date.[26] Named Apsara, the reactor was housed in a 100 x 50 x 70 concrete building. India's and Asia's first nuclear reactor, Apsara reached criticality at 3:45 p.m on 4 August 1956 and was inaugurated by Prime Minister Nehru on 20 January 1957.[25][27][28]