[en] Nuclear Fuel Complex (NFC), Hyderabad, a constituent of Department of Atomic Energy, India manufactures fuel for all Indian nuclear power reactors. Currently NFC manufactures both 19 element & 37 element bundles for catering to the requirement of 220 MWe & 540 MWe PHWRs. In order to meet the growing needs for the Nuclear Fuel, NFC engaged in expansion of the production facilities. This calls for enhanced throughput at various inspection stages keeping in tandem with the production & for achieving this objective, NFC has chosen automation. This paper deals with automation of the inspection line at NFC. (author)

[en] Nuclear Fuel complex (NFC), Hyderabad, manufactures fuel and structural components for both Boiling Water Reactors (BWR) and Pressurised Heavy water (PHWR). Customer and product quality has always been assigned top priority at NFC. At present, NFC is pursuing the goal of attaining six sigma quality levels, the paper brings out the details of various steps initiated and progress made towards the same, with a special reference to end closure welds. (author)

[en] Each 235 MWe PHWR fuel bundle consists of 167 Zircaloy components held together with 328 welds. Production of 30,000 of PHWR fuel bundles per year calls for visual inspection of around 5 million zircaloy components. When manual inspection has to be carried out in such large-scale, there are certain drawbacks. These arise due to limitations of resolution, accessibility, fatigue, improper illumination, environment and absence of quantification ability. Close tolerances, relatively small sizes and reflective surfaces of fuel components further aggravate the problem. This paper tries to bring out the details of the development of the system and its application at NFC

[en] 'Full text:' Advent of Computer aided manufacturing systems has led to very high rate of production with greater reliability. The conventional inspection tools and systems, which are often manual based do not complement with output of highly automated production line. In order to overcome the deficiency, a strategic plan was developed for having automated inspection facility for PHWR fuel assembly line. Laser based systems with their inherently high accuracy and quick response times are a favorite for metrology purpose. Non-contact nature of laser-based measurement ensures minimal contamination, low wear and tear and good repeatability. So far two laser-based systems viz. Pellet density measurement systems and triangulation sensors have been developed. Laser based fuel pellet inspection system and PHWR fuel bundle metric station are under development. Machine vision-based systems have been developed to overcome certain limitations when inspection has to be carried out on such a large scale manually. These deficiencies arise from limitations of resolution, accessibility, fatigue and absence of quantification ability. These problems get further compounded in inspection of fuel components because of their relatively small sizes, close tolerances required and the reflective surfaces. PC based vision system has been developed for inspecting components and fuel assemblies. The paper would touch upon the details of the various laser systems and vision systems that have been indigenously developed for PHWR Fuel Metrology and their impact on the assembly production line. (author)

[en] Nuclear Fuel Complex, Hyderabad is involved in making fuel for PHWR and BWR in the country. Magnesium Di Uranate, which is the raw material for UO₂ pellets is obtained from the Jaduguda and Turamdih. Silicates form the major impurity in the raw material along with carbonates, Alumina and Ferrous oxide. It has been suspected that these impurities in UO₂ powder may alter the microstructure and sintering kinetics. There have been reports that Aluminium Silicate and SiO₂ in limited quantities are used as dopants for obtaining large grained sintered UO₂ pellets by some of the researchers. Thus it is necessary to determine the optimum quantity of dopant to obtain sintered pellets of desired characteristics. The paper brings out the results of the above studies that were carried out

[en] Prototype fast breeder reactor (PFBR) is a 500 MWe, sodium cooled nuclear reactor having mixed oxide viz., (Pu, U)O_2 as fuel. Control and safety rod (CSR) subassembly plays a vital role of controlling the chain reaction in PFBR. This sub assembly along with Diverse safety rod (DSR) sub-assembly together form essential safety features of PFBR. Nuclear Fuel Complex, Hyderabad has successfully manufactures all structural components for these subassemblies and carried out final assembly of these critical sub assemblies

[en] This paper describes a weld quality inspection system that has been developed for QA(F), NFC to evaluate the PHWR end cap welds. The system consists of a trinocular microscope with a video camera connected through a video reduction lens, PCI video frame grabber and PC based acquisition and analysis software. The software developed in the VC++ under windows operating system calculates the non-fusion percentage for the weld specimens in two different modes of computing i.e. Indian welding inspection method and Canadian welding inspection method. The software uses image processing and analysis algorithms to automatically identify the lack of fusion lines as per user supplied parameters for a specific set-up of the system. The lack of fusion lines and the region of interest that was used for computation are marked on the image and can be saved for future reference. GUI for user interaction to delete or add non-fusion lines is also provided. A report generation module has been integrated with the analysis software as per user requirements. Reports are generated for the end cap welding performance including machine set up, machine qualification and operator qualification information. (author)

[en] PHWR fuel bundle essentially consists of a cluster of fuel elements whose ends are welded by endplates to form a bundle. Each fuel pin consists of loaded with sintered UO₂ pellets and the tube ends are hermetically sealed by resistance welding. The end- cap weld of the fuel element is the most critical operation during the fabrication of PHWR fuel bundles. The weld has to maintain its integrity in the harsh reactor environment throughout its residence in the reactor. Any failure in the weld will lead to leakage of fission product in to the coolant circuit. In order to ensure the end-cap weld integrity, stringent quality control procedures are followed. The quality assurance procedure involves qualification of men and machines, while inspection techniques involve both destructive and non-destructive testing, metallographic weld evaluation is carried out on sampling basis. Therefore the paper brings out the details of design and performance of the new semi automatic computerized ultrasonic testing system for PHWR fuel elements. The paper brings out the details of design and performance of the new semi automatic computerized ultrasonic testing system for PHWR fuel elements

[en] Nuclear Fuel Complex (NFC), Hyderabad is the sole manufacturer of fuel for Pressurized Heavy Water Reactor (PHWR) in India. The fuel production was progressively increased due to commissioning of new nuclear power plants and operating the existing ones at design load factors. In order to carry out inspection of millions of components to meet the increasing fuel production requirements, NFC has indigenously developed several automatic and semi-automatic inspection systems. These include systems for fuel pellet density measurement, pellet visual inspection, ultrasonic testing for PHWR end closure welds, PHWR fuel bundle backfilling and leak testing with Helium recirculation and bulk metallographic sample preparation. Introduction of these systems have enhanced inspection throughput with higher reliability while reducing human fatigue and monotony. The paper brings out various details of the various systems and their benefits. (author)

[en] Nuclear Fuel Complex, a constituent of Department of Atomic Energy; India is responsible for manufacturing nuclear fuel in India . Over a million Uranium-di-oxide pellets fabricated per annum need visual inspection . In order to overcome the limitations of human based visual inspection, NFC has undertaken the development of machine vision system. The development involved designing various subsystems viz. mechanical and control subsystem for handling and rotation of fuel pellets, lighting subsystem for illumination, image acquisition system, and image processing system and integration. This paper brings out details of various subsystems and results obtained from the trials conducted. (author)