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News Article | October 26, 2016
Site: www.nature.com

An increase in anti-nuclear sentiment after the Fukushima disaster in Japan in March has stalled India's ambitious plan for nuclear expansion. The plan, pushed forward by Prime Minister Manmohan Singh, aims to use reactors imported from the United States, France and Russia to increase the country's nuclear-power capacity from the present 4,780 megawatts to 60,000 megawatts by 2035, and to provide one-quarter of the country's energy by 2050. But now there are doubts that the targets will ever be met if safety fears persist. Officials say that safety precautions are sufficient to make the proposed reactors, some of which are to be sited along the coasts, immune to natural disasters. But protesters are not listening. In April, violent protests halted construction in Jaitapur in the western state of Maharashtra, where Parisian company Areva is expected to build six 1,650-megawatt European Pressurized Reactors. In August, West Bengal state refused permission for a proposed 6,000-megawatt 'nuclear park' near the town of Haripur, which was slated to host six Russian reactors. The state government said that the area is densely populated, and the hot water discharged from the plants would affect local fishing. On 19 September, following hunger strikes by activists from the People's Movement Against Nuclear Technology, the chief minister of Tamil Nadu state asked Prime Minister Singh to halt work at Koodankulam, about 650 kilometres south of Chennai, where Russia's Atomstroyexport is building two reactors and plans to build four more. The agitations have almost stopped the nuclear expansion programme in its tracks. "We have not begun work on a single reactor from a foreign vendor; even the land has not been acquired," says Swapnesh Malhotra, a spokesman for the Department of Atomic Energy. "Jaitapur and Koodankulam stations will be completed, but there could be delays." Adinarayana Gopalakrishnan, a former chairman of the Indian Atomic Energy Regulatory Board (AERB) and a critic of the import policy, expects the protests to spread. "What you see in Koodankulam and Jaitapur will be repeated in other nuclear parks earmarked for reactors from US suppliers," he says. "My feeling is that except for the two Russian reactors in Koodankulam whose work has already started, there will be no foreign reactors by 2020." The opposition has focused mainly on imported reactors, the designs of which are untried. "The French reactor offered to India is not working anywhere in the world and the Russian reactor had to undergo several design changes before we accepted it," says Annaswamy Prasad, retired director of the Bhabha Atomic Research Centre in Mumbai. "If any accident happens in India it will be in imported reactor and not in our home-made pressurized heavy water reactors" (PHWRs), he adds. Ideally, says Prasad, India should boost its nuclear capacity by building more PHWRs fuelled by natural uranium, instead of importing reactors that require enriched uranium. Although the foreign vendors have agreed to supply fuel for the lifetime of their reactors, overreliance on imports will derail India's home-grown programme, the Bhabha scheme, he warns. The Bhabha scheme involves building PHWRs, which would produce enough plutonium as a by-product to fuel fast-breeder reactors that would in turn convert thorium — which is abundantly available in India — into fissile uranium-233. In the third and final phase, India hopes to run its reactors using the 233U–Th cycle without any need for new uranium. Gopalakrishnan says that building indigenous reactors is not enough: the country must also invest in renewable energy sources, such as wind and solar power. But a survey by Subhas Sukhatme, a former chairman of the Atomic Energy Regulatory Board, warns that India's renewable energy sources, even stretched to their full potential, can at best supply 36.1% of the country's total energy needs by the year 2070. The balance would have to come from fossil fuels and nuclear energy.

Obaidurrahman K.,Indian Atomic Energy Regulatory Board | Doshi J.B.,Indian Institute of Technology Bombay
Annals of Nuclear Energy | Year: 2011

A simple methodology has been developed to assess the spatial dynamic behavior of large PWRs against xenon spatial instability in different modes. Method of analysis aims to analyze xenon dynamic behavior against anticipated reactivity perturbations. Reactivity perturbations in different modes have been evaluated based on reactivity device movements as well as localized thermal variations in the core. Effect of individual core design and operating parameters on xenon spatial instability has been studied. Behavior of spatial stability index (SI) with core size is investigated. Based on SI-core size curve, a threshold core size has been determined beyond which a PWR core tends to become spatially unstable. Methodology has been used to assess the spatial xenon dynamic behavior of different modes of oscillations in VVER1000 and AP1000 reactor cores. © 2010 Elsevier Ltd. All rights reserved.

Rani R.D.,Indian Atomic Energy Regulatory Board | Sasidhar P.,Indian Atomic Energy Regulatory Board
Aquatic Geochemistry | Year: 2012

Sorption of radionuclides onto stable colloids can significantly enhance their transport in groundwater. Batch adsorption studies were performed to evaluate the influence of various experimental parameters like initial pH, contact time, temperature and concentration of Na + and Ca 2+ ions on the sorption of Cs on clay. The sorption process is dependent on pH of the solution with distribution coefficient (K d) found to increase with increase in pH. The kinetic experiments were carried out at different temperatures, and the results have shown that the sorption process fits well into a pseudo-second-order mechanism with apparent activation energy of 45.7 kJ/mol. The rate constant was found to decrease with increase in temperature. The thermodynamic parameters such as ΔG 0, ΔH 0 and ΔS 0 were calculated. The negative value of ΔH 0 indicates that the reaction is exothermic. The negative values obtained for ΔG 0 indicated that the sorption of cesium on clay was spontaneous at all studied concentrations. The distribution coefficient was found to decrease with increasing concentration of Na + and Ca 2+ ions. The cesium sorption data were fitted to Freundlich, Langmuir, Temkin and Dubinin-Radushkevich (D-R) isotherms. The values of Langmuir separation factor (R L) indicate a favorable Cs adsorption. The values of mean free energy of sorption (E) at various temperatures ranged from 10.5 to 11.1 kJ/mol, which indicates that the sorption process follows chemisorption. © 2012 Springer Science+Business Media B.V.

Rani R.D.,Indian Atomic Energy Regulatory Board | Sasidhar P.,Indian Atomic Energy Regulatory Board
Environmental Earth Sciences | Year: 2012

The mobility of strontium in subsurface is largely influenced by sorption on to clay minerals. In the present study, kaolinite clay samples collected from the Kalpakkam nuclear plant site were employed to understand the sorption characteristics of strontium by batch method. The effect of several parameters such as time, strontium ion concentration, pH, temperature and ionic strength was investigated. The kinetic studies suggested pseudo-second-order mechanism. The experimental sorption data was fitted to Langmuir adsorption model for obtaining the sorption capacity of the sorbent. The maximum sorption capacity was 5. 77 mg/g at 298 K and was found to increase with an increase in temperature. It was observed that the distribution coefficient (K d) of strontium on clay increased as the pH of the solution increased. The distribution coefficient was found to decrease with an increase in concentration of Na + and Ca 2+ ions. This variation of K d suggests that cation exchange is the predominant sorption process. It was also observed that sorption process is endothermic. The thermodynamic parameters such as {increment}G 0, {increment}H 0 and {increment}S 0 were calculated. The negative values obtained for {increment}G 0 indicated that the sorption of strontium on clay was spontaneous at all studied concentrations. {increment}G 0 becomes more negative with an increase in temperature, suggests that the sorption process is more favorable at higher temperatures. © 2011 Springer-Verlag.

Sonawane A.U.,Indian Atomic Energy Regulatory Board
Radiation protection dosimetry | Year: 2011

Exposure of children to ionising radiation is considered to carry higher risk than that of adults; therefore a need to suggest diagnostic reference levels (DRLs) for the common paediatric diagnostic X-ray procedures was recognised for the X-ray machines meeting the requirements of the recently implemented Safety Code for Medical Diagnostic X-ray Equipment and Installations in India. Measurements were carried out for entrance surface air kerma (free in air) in conventional paediatric X-ray diagnostic examinations among four age groups: <1, 1-4, 5-9 and 10-15 y. A total of 2240 air kerma measurements at different fixed focus to skin distances were studied for 7 paediatric diagnostic examinations with 11 different projections on 62 X-ray machines installed in 22 selected hospitals in the country. The third quartile values of air kerma per paediatric examination for the age group of 5-9 y were considered as values of paediatric DRLs. The suggested values of DRLs are 0.2 mGy for chest AP/PA, 0.3 mGy for chest LAT, 0.7 mGy for lumber spine AP, 1.3 mGy for lumber spine LAT, 0.3 mGy for thoracic spine AP, 0.6 mGy for thoracic spine LAT, 0.5 mGy for abdomen AP, 0.7 mGy for pelvis AP, 0.6 mGy for skull PA, 0.5 mGy for skull LAT and 0.8 mGy for hip joints AP.

Bajaj S.S.,Indian Atomic Energy Regulatory Board
Energy Procedia | Year: 2011

Over the years, India has mastered all the stages of the nuclear fuel cycle, which include mining, processing & fabrication of nuclear fuel; design, construction, and operation of nuclear power reactors and research reactors; reprocessing of spent fuel and management of radioactive wastes. Ionising radiation is also used widely in medical, industrial and research areas. Since its inception, Department of Atomic Energy (DAE) was enforcing radiological safety in the country through in -house or ad-hoc committees, till a dedicated regulatory body (AERB) was set up 25 years ago. Today India is operating 19 nuclear power plants with different vintages (2 BWRs and 17 PHWRS) and another 8 (1 PFBR, 5 PHWRs and 2 PWRs) are in various stages of construction. Recently there are new evolutionary reactors (AHWRs) for which design has been completed and are on the threshold for consideration for construction. To match the rapid growth in the need for power India is also about to take up construction of large evolutionary PWRs of foreign design. This variety in the Indian nuclear power programme has come up due to a systematic evaluation and optimisation of the resources and technology available within the country. Added to this is the growing use of radiation in non -power applications. As the safety supervision of this huge programme is the responsibility of AERB, it faces various challenges, like, • Strategies for regulating wide variety of nuclear and radiation facilities with wide dispersal; • Meeting present day expectations with regard to nuclear and radiation safety and nuclear security; • The safety and security of large number of radioactive sources spread over such a vast country and of the associated import/export guidance; • Ensuring safety of old plants by periodic reviews and by prescribing adequate safety upgradation and ageing mana gement programme; • Adaptation of the regulatory system and of regulations to new and foreign design nuclear technologies and applications; • Developing competence in wide variety of technologies and different reactor designs; • Developing adequate human resource ready for safety supervision of this huge nuclear and radiation programme; • Approach to regulatory research related to new technologies. Apart from the above mentioned issues regulatory challenges may arise from policies to make all energy se ctors competitive. With growing competition, it is becoming increasingly important to reconcile commercial interests with safety requirements. For AERB, the first challenge will be to ensure that economic pressures do not erode nuclear safety. To maintain highest level of safety culture, AERB will also need to adapt to an increasingly market -oriented environment and new working relationships with utilities. Although it is a difficult task, the Board has also evolved systematically over the years and now has an efficient structure, which is capable of facing the current challenges. © 2011 Published by Elsevier Ltd.

Pisharady A.S.,Indian Atomic Energy Regulatory Board | Basu P.C.,Indian Atomic Energy Regulatory Board
Nuclear Engineering and Design | Year: 2010

Seismic fragility of structure, system or component (SSC) is the probability of its reaching a limit state, for a given seismic demand. It is evaluated in terms of ground motion parameters, which is generally peak ground acceleration. Seismic fragility of a nuclear power plant (NPP) is derived from the fragility of its SSC. Seismic qualification, prerequisite for determination of seismic fragility of the SSC of a NPP, is conducted by either direct method involving analysis and testing; or indirect one involving experience based method. The paper surveys and summarizes the methods available to derive the seismic fragility of SSC(s) of an NPP, which are qualified by direct as well as indirect methods. © 2010 Elsevier B.V. All rights reserved.

Chowdhury S.,Ultratech | Basu P.C.,Indian Atomic Energy Regulatory Board
ACI Materials Journal | Year: 2010

Under identical conditions of mixing, curing, compaction, and testing, the relationship between the compressive strength of concrete (fc) and water-cementitious material ratio (w/cm) is critical to proportion a workable concrete mixture for specified target properties. The relationship between strength and w/cm is developed in the generic format for fly ash-based concrete involving nondimensional parameters; strength ratio (fc/f m), and w/cm. The fc/fm is the ratio of f c and compressive strength of the standard mortar (fm). The standard mortar is proportioned with the cementitious material of the same composition and fine aggregates that will be used in the concrete mixture. The fm is tested following the standard procedure to test the compressive strength of cement. The hydration characteristics of cementitious materials are incorporated in the relation. The test results confirm the satisfactory performance of a new relation in proportioning a fly-ash-based concrete mixture. Copyright & 2010, American Concrete Institute. All rights reserved.

Chowdhury S.,Ultratech | Basu P.C.,Indian Atomic Energy Regulatory Board
ACI Materials Journal | Year: 2010

A new methodology to proportion self-consolidating concrete (SCC) suitable for high-volume ASTM Class F fly ash content is introduced. Ingredients are determined from explicit criteria on strength and rheology. The water-cementitious material ratio (w/cm) is derived from the model systematically developed for this study. The quantity of chemical admixture and fine aggregates are determined from the Theological requirement. Finally, the quantity of coarse aggregate is calculated using the absolute volume method and finalized by adjusting the volume fractions. The suitability of the method is examined by proportioning SCC mixtures with different powder composition and fine aggregate types. The workability and compressive strength as well as the split tensile strength of these mixtures are tested. The results suggested that the method was adequate to proportion SCC mixtures with ingredients used in this study, satisfying both of the requirements of strength and rheology. Copyright © 2010, American Concrete Institute. All rights reserved.

Roshan A.D.,Indian Atomic Energy Regulatory Board | Basu P.C.,Indian Atomic Energy Regulatory Board
Nuclear Engineering and Design | Year: 2010

Probabilistic seismic hazard analysis (PSHA) is a rational approach for deriving the design basis ground motion parameters and also a key step for seismic probabilistic risk analysis (SPRA). This paper elaborates the application of probabilistic seismic hazard analysis (PSHA) technique, following Cornell-McGuire method, to develop uniform hazard spectra (UHS) in low seismic region. The application is described through a case study of deriving UHS at free field condition of an NPP site in peninsular India. Peninsular India is a low seismic zone and poses challenges like scarcity of data on seismicity, lack of information on seismotectonic characteristics, non-availability of regional specific attenuation relationships in application of this method. The effect of uncertainties associated with input parameters arising out of these were taken into account by rational maximization of hazard. This is achieved with the help of sensitivity study. De-aggregation of hazard is carried out to examine the relative contribution of some major parameters like source-distance from site, earthquake magnitude. Based on the outcome of sensitivity analysis and de-aggregation, both aleatory and epistemic uncertainties in depiction of various parameters are incorporated in derivation of UHS using logic tree. The branches of logic tree are derived by postulating alternate hypotheses for some parameters and introducing additional variance in case of other parameters. © 2010 Elsevier B.V. All rights reserved.

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