scholarly journals Nuclear viewpoint in India

2017 ◽  
Vol 4 ◽  
Author(s):  
Anshu Bharadwaj ◽  
Lakshminarayana Venkat Krishnan ◽  
Subramaniam Rajagopal

ABSTRACTNuclear power is a crucial source of clean energy for India. In the near-term, India is focusing on thermal reactors using natural and enriched uranium. In the long-term, India is exploring various options to use its large thorium reserves.India’s present nuclear installed capacity is 5680 MW, which contributes to about 3.4% of the annual electricity generation. However, nuclear power is an important source of energy in India’s aspirations for energy security and also in achieving its Intended Nationally Determined Contributions (INDC), of 40% fossil free electricity, by 2030. India has limited uranium reserves, but abundant thorium reserves. The Nuclear Suppliers Group (NSG) lifted restrictions on trade with India, in 2008, enabling India to import uranium (natural and enriched) and nuclear reactors. In the near–term (2030), the nuclear capacity could increase to about 42,000 MW. This would be from a combination of domestic Pressurized Heavy Water Reactors (PHWR) and imported Pressurized Water Reactors (PWR). For the long–term (2050), India is exploring various options for utilising its vast thorium reserves. This includes Advanced Heavy Water Reactor and Molten Salt Breeder Reactor. However, generating public acceptance will be crucial to the expansion of the nuclear power program.

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 754-761 ◽  
Author(s):  
Ede Hertelendi ◽  
György Uchrin ◽  
Peter Ormai

We present results of airborne 14C emission measurements from the Paks PWR nuclear power plant. Long-term release of 14C in the form of carbon dioxide or carbon monoxide and hydrocarbons were simultaneously measured. The results of internal gas-proportional and liquid scintillation counting agree well with theoretical assessments of 14C releases from pressurized water reactors. The mean value of the 14C concentration in discharged air is 130Bqm-3 and the normalized release is equal to 740GBq/GWe · yr. > 95% of 14C released is in the form of hydrocarbons, ca 4% is apportioned to CO2, and <1% to CO. Tree-ring measurements were also made and indicated a minute increase of 14C content in the vicinity of the nuclear power plant.


2021 ◽  
Vol 8 (3A) ◽  
Author(s):  
Ricardo Bastos Smith ◽  
Mahima Sachdeva ◽  
Indranil Bisuri ◽  
Roberto Vicente

One of the great advances in the current evolution of nuclear power reactors is occurring in India, with the Advanced Heavy Water Reactor (AHWR). It is a reactor that uses thorium as part of its fuel, which in its two fueling cycle options, in conjunction with plutonium or low enriched uranium, produces energy at the commercial level, generating less actinides of long half-life and inert thorium oxide, which leads to an optimization in the proportion of energy produced versus the production of burnt fuels of the order of up to 50%. The objective of this work is to present the most recent research and projects in progress in India, and how the expected results should be in compliance with the current sustainability models and programs, especially the "Green Chemistry", a program developed since the 1990s in the United States and England, which defines sustainable choices in its twelve principles and that can also be mostly related to the nuclear field. Nevertheless, in Brazil, for more than 40 years there has been the discontinuation of research for a thorium-fueled reactor, and so far there has been no prospect of future projects. The AHWR is an important example as an alternative way of producing energy in Brazil, as the country has the second largest reserve of thorium on the planet.


Author(s):  
Romney B. Duffey

Nuclear energy must be made available, freely and readily, to help meet world energy needs. The perspective offered here is a model for others to consider, adopting and adapting using whatever elements fit their own strategies and needs. The underlying philosophy is to retain flexibility in the reactor development, deployment and fuel cycle, while ensuring the principle that customer, energy market, safety, non-proliferation and sustainability needs are all addressed. Canada is the world’s largest exporter of uranium, providing about one-third of the world supply for nuclear power reactors. Canada’s Atomic Energy of Canada Limited (AECL) has developed a unique world-class nuclear power reactor technology — the CANDU® reactor based on the Pressure Tube Reactor (PTR) concept, moderated by heavy water (D2O), also sometimes called the Pressurized Heavy Water reactor or PHWR. With expectations of significant expansion in nuclear power programs worldwide and the resultant concerns about uranium availability and price, there is a growing desire to improve resource utilization by extracting more energy from each tonne of mined fissionable material. Attention is therefore being increasingly focused on fuel cycles that are more energy efficient, reduce waste streams and ensure sustainable futures. There are also many compelling reasons to utilize advanced fuel cycles in PTR (CANDU-type) thermal spectrum reactors. Because of its inherent technical characteristics, PTRs have a great deal of fuel cycle flexibility. The combination of relatively high neutron efficiency (provided by heavy water moderation and careful selection of core materials), on-line fuelling capability and simple fuel bundle design mean that PTR reactors can use not only natural and enriched uranium, but also a wide variety of other fuels including thorium-based fuels and those resulting from the recycle of irradiated fuel. In addition, the PTR can be optimized as a very effective “intermediate burner” to provide efficient fuel cycles that remove residual minor actinides. This inherent fuel cycle flexibility offers many technical, resource and sustainability, and economic advantages over other reactor technologies and is the subject of this paper. The design evolution and intent is to be consistent with improved or enhanced safety, licensing and operating limits and global proliferation concerns, and sustainable energy futures.


Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 668-672 ◽  
Author(s):  
Pavel Povinec ◽  
Martin Chudý ◽  
Alexander Šivo

14C is one of the most important anthropogenic radionuclides released to the environment by human activities. Weapon testing raised the 14C concentration in the atmosphere and biosphere to +100% above the natural level. This excess of atmospheric C at present decreases with a half-life of ca 7 years. Recently, a new source of artificially produced 14C in nuclear reactors has become important. Since 1967, the Bratislava 14C laboratory has been measuring 14C in atmospheric 14CO2 and in a variety of biospheric samples in densely populated areas and in areas close to nuclear power plants. We have been able to identify a heavy-water reactor and the pressurized water reactors as sources of anthropogenic 14C. 14C concentrations show typical seasonal variations. These data are supported by measurements of 3H and 85Kr in the same locations. Results of calculations of future levels of anthropogenic 14C in the environment due to increasing nuclear reactor installations are presented.


Author(s):  
Dong-Chul Jung ◽  
Ki Bong Seong

SKN(Shin Kori Nuclear Power Plant) Unit 3, the first unit of APR1400 reactor in Republic of Korea, which is under construction, is scheduled to realize 18-month cycle operation strategy from its initial core. SKN Unit 3 is a pressurized water reactor with a thermal output of 4000 MWth having 3-batch 241 fuel assemblies. Its target cycle length will be realized as long term(about 455 EFPD) directly from initial core, although most of previous other plants had been started according to their annual or 15-month cycle operation schedule at their initial core and gone to 18-month after 3rd ∼ 4th cycle. SKN Unit 3 has also been designed by meeting the following requirements as well as the above cycle length requirement; 1) peaking factor (Fxy) ≤ 1.60, 2) Negative MTC(Moderator Temperature Coefficient), 3) thermal margin ≥ 10%, 4) sufficient shutdown margin. 5) Xe stability, 6) CEA(Control Element Assembly) Re-arrangement, etc,. Higher enriched assemblies used to accomplish long term cycle at the initial core make higher radial and axial peaking factor than those of OPR1000. APR1400 introduces axial cutback region in a gadolinia fuel rod(6″ in each of top and bottom) and axial blanket region in a normal fuel rod(6″ in each of top and bottom) with low enriched uranium to enhance the neutron economy. It is also expected for these optimized cutback and blanket length to provide an advantage to reduce or avoid xenon oscillation phenomenon in power ascension test(PAT). In order to enhance core operability (RPCS requirement, Xe oscillation control and performance related design requirements, etc,.) as well as meeting shutdown margin requirement, CEA re-arrangement were also made. In this paper, APR1400 core design experience including all other design endeavors will be introduced.


Author(s):  
Per Segerud ◽  
Joseph Boucau ◽  
Stefan Fallstro¨m ◽  
Paul J. Kreitman

Some commercial nuclear power plants have been permanently shut down to date and decommissioned using dismantling methods. Other operating plants have decided to undergo an upgrade process that includes replacement of reactor internals. In both cases, there is a need to perform a segmentation of the reactor vessel internals with proven methods for long term waste disposal. Westinghouse has developed several concepts to dismantle reactor internals based on safe and reliable techniques, including plasma arc cutting (PAC), abrasive waterjet cutting (AWJC), metal disintegration machining (MDM), or mechanical cutting. Mechanical cutting has been used by Westinghouse since 1999 for both Pressurized Water Reactors (PWR’s) and Boiling Water Reactors (BWR’s) and its process has been continuously improved over the years. The complexity of the work requires well designed and reliable tools. Different band saws, disc saws, tube cutters and shearing tools have been developed to cut the reactor internals. All of those equipments are hydraulically driven which is very suitable for submerged applications. Westinghouse experience in mechanical cutting has demonstrated that it is an excellent technique for segmentation of internals. In summary, the purpose of this paper will be to provide an overview of the Westinghouse mechanical segmentation process, based on actual experience from the work that has been completed to date.


Radiocarbon ◽  
2014 ◽  
Vol 56 (3) ◽  
pp. 1107-1114 ◽  
Author(s):  
Zhongtang Wang ◽  
Dan Hu ◽  
Hong Xu ◽  
Qiuju Guo

Atmospheric CO2 and aquatic water samples were analyzed to evaluate the environmental 14C enrichment due to operation of the Qinshan nuclear power plant (NPP), where two heavy-water reactors and five pressurized-water reactors are employed. Elevated 14C-specific activities (2–26.7 Bq/kg C) were observed in the short-term air samples collected within a 5-km radius, while samples over 5 km were close to background levels. The 14C-specific activities of dissolved inorganic carbon (DIC) in the surface seawater samples ranged from 196.8 to 206.5 Bq/kg C (average 203.4 Bq/kg C), which are close to the background value. No elevated 14C level in surface seawater was found after 20 years of operation of Qinshan NPP, indicating that the 14C discharged was well diffused. The results of the freshwater samples show that excess 14C-specific activity (average 17.1 Bq/kg C) was found in surface water and well water samples, while no obvious 14C increase was found in drinking water (groundwater and tap water) compared to the background level.


2020 ◽  
Vol 12 (12) ◽  
pp. 5149
Author(s):  
Ga Hyun Chun ◽  
Jin-ho Park ◽  
Jae Hak Cheong

Although the generation of large components from nuclear power plants is expected to gradually increase in the future, comprehensive studies on the radiological risks of the predisposal management of large components have been rarely reported in open literature. With a view to generalizing the assessment framework for the radiological risks of the processing and transport of a representative large component—a steam generator—12 scenarios were modeled in this study based on past experiences and practices. In addition, the general pathway dose factors normalized to the unit activity concentration of radionuclides for processing and transportation were derived. Using the general pathway dose factors, as derived using the approach established in this study, a specific assessment was conducted for steam generators from a pressurized water reactor (PWR) or a pressurized heavy water reactor (PHWR) in Korea. In order to demonstrate the applicability of the developed approach, radiation doses reported from actual experiences and studies are compared to the calculated values in this study. The applicability of special arrangement transportation of steam generators assumed in this study is evaluated in accordance with international guidance. The generalized approach to assessing the radiation doses can be used to support optimizing the predisposal management of large components in terms of radiological risk.


2013 ◽  
Vol 10 (2) ◽  
pp. 6-10 ◽  
Author(s):  
Petr Pospíšil

Abstract Some commercial nuclear power plants have been permanently shut down to date and decommissioned using dismantling methods. Other operating plants have decided to undergo an upgrade process that includes replacement of reactor internals. In both cases, there is a need to perform a segmentation of the reactor vessel internals with proven methods for long term waste disposal. Westinghouse has developed several concepts to dismantle reactor internals based on safe and reliable techniques, including plasma arc cutting (PAC), abrasive waterjet cutting (AWJC), metal disintegration machining (MDM), or mechanical cutting. Mechanical cutting has been used by Westinghouse since 1999 for both Pressurized Water Reactors (PWR’s) and Boiling Water Reactors (BWR’s) and its process has been continuously improved over the years. The complexity of the work requires well designed and reliable tools. Different band saws, disc saws, tube cutters and shearing tools have been developed to cut the reactor internals. All of those equipments are hydraulically driven which is very suitable for submerged applications. Westinghouse experience in mechanical cutting has demonstrated that it is an excellent technique for segmentation of internals. In summary, the purpose of this paper will be to provide an overview of the Westinghouse mechanical segmentation process, based on actual experience from the work that has been completed to date.


1982 ◽  
Vol 26 (7) ◽  
pp. 659-663
Author(s):  
Les Ainsworth

The American and British nuclear power programmes have in the past taken divergent routes, with the Americans choosing pressurized water reactors, whilst the British have opted for gas cooling. Although the technology and plant design for these two systems encompasses many fundamental differences, some of which have ramifications for the controllers, the basic task of monitoring and controlling a reactor holds many similarities in both countries. It is therefore instructive to compare and contrast the approaches which have been taken to human factors in nuclear power plant control room design on both sides of the Atlantic.


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