Nuclear fuel element end fitting

International Nuclear Information System (INIS)

Jabsen, F.S.

1979-01-01

A typical embodiment of the invention has an array of sockets that are welded to the intersections of the plates that form the upper and lower end fittings of a nuclear reactor fuel element. The sockets, which are generally cylindrical in shape, are oriented in directions that enable the longitudinal axes of the sockets to align with the longitudinal axes of the fuel rods that are received in the respective sockets. Detents impressed in the surfaces of the sockets engage mating grooves that are formed in the ends of the fuel rods to provide for the structural integrity of the fuel element

Nuclear fuel cycle modelling using MESSAGE

International Nuclear Information System (INIS)

Guiying Zhang; Dongsheng Niu; Guoliang Xu; Hui Zhang; Jue Li; Lei Cao; Zeqin Guo; Zhichao Wang; Yutong Qiu; Yanming Shi; Gaoliang Li

2017-01-01

In order to demonstrate the possibilities of application of MESSAGE tool for the modelling of a Nuclear Energy System at the national level, one of the possible open nuclear fuel cycle options based on thermal reactors has been modelled using MESSAGE. The steps of the front-end and back-end of nuclear fuel cycle and nuclear reactor operation are described. The optimal structure for Nuclear Power Development and optimal schedule for introducing various reactor technologies and fuel cycle options; infrastructure facilities, nuclear material flows and waste, investments and other costs are demonstrated. (author)

Nuclear Fuel Cycle Evaluation and Real Options

Directory of Open Access Journals (Sweden)

L. Havlíček

2008-01-01

Full Text Available The first part of this paper describes the nuclear fuel cycle. It is divided into three parts. The first part, called Front-End, covers all activities connected with fuel procurement and fabrication. The middle part of the cycle includes fuel reload design activities and the operation of the fuel in the reactor. Back-End comprises all activities ensuring safe separation of spent fuel and radioactive waste from the environment. The individual stages of the fuel cycle are strongly interrelated. Overall economic optimization is very difficult. Generally, NPV is used for an economic evaluation in the nuclear fuel cycle. However the high volatility of uranium prices in the Front-End, and the large uncertainty of both economic and technical parameters in the Back-End, make the use of NPV difficult. The real option method is able to evaluate the value added by flexibility of decision making by a company under conditions of uncertainty. The possibility of applying this method to the nuclear fuel cycle evaluation is studied. 

On the problems of the fuel cycles of nuclear fuels

International Nuclear Information System (INIS)

Schmidt-Kuester, W.J.; Wagner, H.F.

1976-01-01

A secured procurement with nuclear energy can be only achieved if a completely closed fuel cycle will be established. In the Federal Republic of Germany efforts are concentrated on the front end as well as on the back end of the fuel cycle. At the front end the main tasks are to secure uranium supply and to establish the necessary enrichment capacity. The German concept for the back end of the fuel cycle will provide for an integrated and co-located system for all necessary facilities including reprocessing, plutonium fuel fabrication, treatment, interim storage and final disposal of the radioactive wastes to be operational in the mid-80's. Responsibilities for establishing this system are shared between government and private industry. Government will provide for final waste disposal, industry will built and operate the other facilities. Another important point for the introduction of nuclear energy is to solve reliably the problems of protection of fissionable material, radioactive waste and nuclear facilities. German government has initiated respective activities and has started appropriate R+D-work. (orig.) [de

Emerging Trends in the Nuclear Fuel Cycle: Implications for Waste Management

International Nuclear Information System (INIS)

Spradley, L.; Camper, L.; Rehmann, M.

2009-01-01

There are emerging trends in the nuclear fuel cycle that have implications for waste management. This paper will discuss activities in both the front-end and back-end of the nuclear fuel cycle for the U.S. Nuclear Regulatory Commission (NRC)-regulated entities. Particular focus will be given to the front-end which includes uranium recovery facilities, conversion facilities, and enrichment facilities. The back-end activities include progress on the proposed high-level waste geologic repository at Yucca Mountain, NV and efforts to reprocess spent nuclear fuel or down-blend HEU. While there are potential environmental impacts due to construction and dismantling of fuel cycle facilities, this paper focuses on the operational waste stream that will need to be managed as a result of fuel-cycle facilities. (authors)

Back-end of the nuclear fuel cycle

International Nuclear Information System (INIS)

Choi, J.S.

2002-01-01

Current strategies of the back-end nuclear fuel cycles are: (1) direct-disposal of spent fuel (Open Cycle), and (2) reprocessing of the spent fuel and recycling of the recovered nuclear materials (Closed Cycle). The selection of these strategies is country-specific, and factors affecting selection of strategy are identified and discussed in this paper. (author)

Nuclear fuel rod end plug weld inspection

International Nuclear Information System (INIS)

Parker, M. A.; Patrick, S. S.; Rice, G. F.

1985-01-01

Apparatus and method for testing TIG (tungsten inert gas) welds of end plugs on a sealed nuclear reactor fuel rod. An X-ray fluorescent spectrograph testing unit detects tungsten inclusion weld defects in the top end plug's seal weld. Separate ultrasonic weld inspection system testing units test the top end plug's seal and girth welds and test the bottom end plug's girth weld for penetration, porosity and wall thinning defects. The nuclear fuel rod is automatically moved into and out from each testing unit and is automatically transported between the testing units by rod handling devices. A controller supervises the operation of the testing units and the rod handling devices

Design and simulation of front end power converter for a microgrid with fuel cells and solar power sources

Science.gov (United States)

Jeevargi, Chetankumar; Lodhi, Anuj; Sateeshkumar, Allu; Elangovan, D.; Arunkumar, G.

2017-11-01

The need for Renewable Energy Sources (RES) is increasing due to increased demand for the supply of power and it is also environment friendly.In the recent few years, the cost of generation of the power from the RES has been decreased. This paper aims to design the front end power converter which is required for integrating the fuel cells and solar power sources to the micro grid. The simulation of the designed front end converter is carried out in the PSIM 9.1.1 software. The results show that the designed front end power converter is sufficient for integrating the micro grid with fuel cells and solar power sources.

Radiation exposure monitoring and control in front-end fuel cycle facilities

International Nuclear Information System (INIS)

Khan, A.H.

2003-01-01

The front end nuclear fuel cycle facilities presently operational in India are the mining and processing of beach mineral sands along the southern coast of Kerala, Tamilnadu and Orissa, mining and processing of uranium ore in Singhbhum-East in Jharkhand and refining and fuel fabrication at Hyderabad and Trombay. Dedicated Health Physics Units set up at each site regularly carry out in-plant and personnel monitoring to ensure safe working conditions and evaluate radiation exposure of workers and advise appropriate control measures. External gamma radiation, radon, thoron, their progeny and airborne long-lived activity due to radioactive dust are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the plant and personal monitoring data. Provision of adequate ventilation, control of dust and spillage of active solutions, prompt decontamination, use of personal protective appliances and worker education are the key factors in keeping the doses to the workers well within the regulatory limits. It has been observed that the total radiation dose to workers has been well below 20 mSv.y - 1 at all stages of operations. The monitoring methodologies and summary of radiation exposure data for different facilities during the last few years are presented in the paper. (author)

The nuclear fuel cycle

International Nuclear Information System (INIS)

Patarin, L.

2002-01-01

This book treats of the different aspects of the industrial operations linked with the nuclear fuel, before and after its use in nuclear reactors. The basis science of this nuclear fuel cycle is chemistry. Thus a recall of the elementary notions of chemistry is given in order to understand the phenomena involved in the ore processing, in the isotope enrichment, in the fabrication of fuel pellets and rods (front-end of the cycle), in the extraction of recyclable materials (residual uranium and plutonium), and in the processing and conditioning of wastes (back-end of the fuel cycle). Nuclear reactors produce about 80% of the French electric power and the Cogema group makes 40% of its turnover at the export. Thus this book contains also some economic and geopolitical data in order to clearly position the stakes. The last part, devoted to the management of wastes, presents the solutions already operational and also the research studies in progress. (J.S.)

The nuclear fuel cycle

International Nuclear Information System (INIS)

Jones, P.M.S.

1987-01-01

This chapter explains the distinction between fissile and fertile materials, examines briefly the processes involved in fuel manufacture and management, describes the alternative nuclear fuel cycles and considers their advantages and disadvantages. Fuel management is usually divided into three stages; the front end stage of production and fabrication, the back end stage which deals with the fuel after it is removed from the reactor (including reprocessing and waste treatment) and the stage in between when the fuel is actually in the reactor. These stages are illustrated and explained in detail. The plutonium fuel cycle and thorium-uranium-233 fuel cycle are explained. The differences between fuels for thermal reactors and fast reactors are explained. (U.K.)

Nuclear fuel cycle, nuclear fuel makes the rounds: choosing a closed fuel cycle, nuclear fuel cycle processes, front-end of the fuel cycle: from crude ore to enriched uranium, back-end of the fuel cycle: the second life of nuclear fuel, and tomorrow: multiple recycling while generating increasingly less waste

International Nuclear Information System (INIS)

Philippon, Patrick

2016-01-01

France has opted for a policy of processing and recycling spent fuel. This option has already been deployed commercially since the 1990's, but will reach its full potential with the fourth generation. The CEA developed the processes in use today, and is pursuing research to improve, extend, and adapt these technologies to tomorrow's challenges. France has opted for a 'closed cycle' to recycle the reusable materials in spent fuel (uranium and plutonium) and optimise ultimate waste management. France has opted for a 'closed' nuclear fuel cycle. Spent fuel is processed to recover the reusable materials: uranium and plutonium. The remaining components (fission products and minor actinides) are the ultimate waste. This info-graphic shows the main steps in the fuel cycle currently implemented commercially in France. From the mine to the reactor, a vast industrial system ensures the conversion of uranium contained in the ore to obtain uranium oxide (UOX) fuel pellets. Selective extraction, purification, enrichment - key scientific and technical challenges for the teams in the Nuclear Energy Division (DEN). The back-end stages of the fuel cycle for recycling the reusable materials in spent fuel and conditioning the final waste-forms have reached maturity. CEA teams are pursuing their research in support of industry to optimise these processes. Multi-recycle plutonium, make even better use of uranium resources and, over the longer term, explore the possibility of transmuting the most highly radioactive waste: these are the challenges facing future nuclear systems. (authors)

The safety of the nuclear fuel cycle

International Nuclear Information System (INIS)

2005-01-01

The procurement and preparation of fuel for nuclear power reactors, followed by its recovery, processing and management subsequent to reactor discharge, are frequently referred to as the ''front end'' and ''back end'' of the nuclear fuel cycle. The facilities associated with these activities have an extensive and well-documented safety record accumulated over the past 50 years by technical experts and safety authorities. This information has enabled an in-depth analysis of the complete fuel cycle. Preceded by two previous editions in 1981 and 1993, this new edition of the Safety of the Nuclear Fuel Cycle represents the most up-to-date analysis of the safety aspects of the nuclear fuel cycle. It will be of considerable interest to nuclear safety experts, but also to those wishing to acquire extensive information about the fuel cycle more generally. (author)

The safety of the nuclear fuel cycle

International Nuclear Information System (INIS)

2005-10-01

The procurement and preparation of fuel for nuclear power reactors, followed by its recovery, processing and management subsequent to reactor discharge, are frequently referred to as the 'front end' and 'back end' of the nuclear fuel cycle. The facilities associated with these activities have an extensive and well-documented safety record accumulated over the past 50 years by technical experts and safety authorities. This information has enabled an in-depth analysis of the complete fuel cycle. Preceded by two previous editions in 1981 and 1993, this new edition of The Safety of the Nuclear Fuel Cycle represents the most up-to-date analysis of the safety aspects of the nuclear fuel cycle. It will be of considerable interest to nuclear safety experts, but also to those wishing to acquire extensive information about the fuel cycle more generally. (author)

Microscopic Examination of a Corrosion Front in Spent Nuclear Fuel

International Nuclear Information System (INIS)

J.A. Fortner; A.J. Kropf; R.J. Finch; J.C. Cunnane

2006-01-01

Spent uranium oxide nuclear fuel hosts a variety of trace chemical constituents, many of which must be sequestered from the biosphere during fuel storage and disposal. In this paper we present synchrotron x-ray absorption spectroscopy and microscopy findings that illuminate the resultant local chemistry of neptunium and plutonium within spent uranium oxide nuclear fuel before and after corrosive alteration in an air-saturated aqueous environment. We find the plutonium and neptunium in unaltered spent fuel to have a +4 oxidation state and an environment consistent with solid-solution in the UO 2 matrix. During corrosion in an air-saturated aqueous environment, the uranium matrix is converted to uranyl U(VI)O 2 2+ mineral assemblage that is depleted in plutonium and neptunium relative to the parent fuel. At the corrosion front interface between intact fuel and the uranyl-mineral corrosion layer, we find evidence of a thin (∼20 micrometer) layer that is enriched in plutonium and neptunium within a predominantly U 4+ environment. Available data for the standard reduction potentials for NpO 2+ /Np 4+ and UO 2 2+ /U 4+ couples indicate that Np(IV) may not be effectively oxidized to Np(V) at the corrosion potentials of uranium dioxide spent nuclear fuel in air-saturated aqueous solutions. Neptunium is an important radionuclide in dose contribution according to performance assessment models of the proposed U. S. repository at Yucca Mountain, Nevada. A scientific understanding of how the UO 2 matrix of spent nuclear fuel impacts the oxidative dissolution and reductive precipitation of neptunium is needed to predict its behavior at the fuel surface during aqueous corrosion. Neptunium would most likely be transported as aqueous Np(V) species, but for this to occur it must first be oxidized from the Np(IV) state found within the parent spent nuclear fuel [1]. In the immediate vicinity of the spent fuel's surface the redox and nucleation behavior is likely to promote

End plug welding of nuclear fuel elements-AFFF experience

International Nuclear Information System (INIS)

Bhatt, R.B.; Singh, S.; Aniruddha Kumar; Amit; Arun Kumar; Panakkal, J.P.; Kamath, H.S.

2004-01-01

Advanced Fuel Fabrication Facility is engaged in the fabrication of mixed oxide (U,Pu)O 2 fuel elements of various types of nuclear reactors. Fabrication of fuel elements involves pellet fabrication, stack making, stack loading and end plug welding. The requirement of helium bonding gas inside the fuel elements necessitates the top end plug welding to be carried out with helium as the shielding gas. The severity of the service conditions inside a nuclear reactor imposes strict quality control criteria, which demands for almost defect free welds. The top end plug welding being the last process step in fuel element fabrication, any rejection at this stage would lead to loss of effort prior to this step. Moreover, the job becomes all the more difficult with mixed oxide (MOX) as the entire fabrication work has to be carried out in glove box trains. In the case of weld rejection, accepted pellets are salvaged by cutting the clad tube. This is a difficult task and recovery of pellets is low (requiring scrap recovery operation) and also leads to active metallic waste generation. This paper discusses the experience gained at AFFF, in the past 12 years in the area of end plug welding for different types of MOX fuel elements

Fuel cycle management by the electric enterprises and spanish nuclear Power plants

International Nuclear Information System (INIS)

Celma, E. M.; Gonzalez, C.; Lopez, J. V.; Melara, J.; Lopez, L.; Martinez, J. C.; Culbras, F.; Blanco, J.; Francia, L.

2015-01-01

The Nuclear Fuel Group reports to the Technology Committee of the UNESA Nuclear Energy Committee, and is constituted by representatives of both the Spanish Utilities and the Nuclear Power Plants. The Group addresses the nuclear plant common issues in relation to the operation and management of the nuclear fuel in their different stages of the Fuel Cycle. The article reviews the activities developed by the Group in the Front-End, mainly in the monitoring of international programs that define criteria to improve the Fuel Reliability and in the establishment of common bases for the implementation of changes in the regulation applying the nuclear fuel. Concerning the Back-End the Group focuses on those activities of coordination with third parties related to the management of used fuel. (Author)

Transportation risks in the US nuclear fuel cycle

International Nuclear Information System (INIS)

Rhoads, R.E.; Andrews, W.B.

1980-01-01

Estimated risks associated with accidental releases of materials transported for each step of the nuclear fuel cycle are presented. The risk estimates include both immediate and latent fatilities caused by releases of these materials in transportation accidents. Studies of the risk of transporting yellowcake, fresh nuclear and low level wastes from the front end of the fuel cycle have not been completed. Existing information does permit estimates of the risks to be made. The estimates presented result from the very low hazards associated with release of these materials. These estimates are consistent with the results of other studies. The results show that risks from all the fuel cycle transportation steps are low. The results also indicate that the total transportation risks associated with the nuclear fuel cycle are distributed about evenly between the fuel supply end and waste management end of the cycle. Risks in the front end of the cycle result primarily from the chemical toxicity of the materials transported. The results of the risk analysis studies for transportation of nuclear fuel cycle materials are compared with the results for the three studies that have been completed for non-nuclear systems. The risk analysis methodology used in these studies identifies the complete spectrum of potential accident consequences and estimates the probability of events producing that level of consequence. The maximum number of fatalities predicted for each material is presented. A variety of risk measures have been used because of the inherent difficulties in making risk comparisons. Examination of a number of risk measures can provide additional insights and help guard against conclusions that are dependent on the way the risk information has been developed and displayed. The results indicate that the risks from transporting these materials are all relatively low in comparison to other risks in society

The back-end of the nuclear fuel cycle: The Argentine view

International Nuclear Information System (INIS)

Stevens, C.E.

2002-01-01

The strategy of the back-end nuclear fuel cycle for Argentina is presented in this paper. Although one may consider Argentina's current policy on spent fuel management as 'wait and see', Argentina is continuously directing her efforts towards the development of technology and human resources for the future demand of the closure of the nuclear fuel cycle. (author)

Materials reliability in the back end of the nuclear fuel cycle

International Nuclear Information System (INIS)

1987-05-01

Operating experience of nuclear fuel cycle facilities has proved that the performance and availability of key equipment largely depend on the reliability of its construction materials. In general, the materials of construction have performed well in accordance with the design criteria of equipment. In some cases, however, materials failure problems have been encountered, the causes of which are related to their corrosion and mechanical degradation. In response to the growing interest in these topics, the IAEA convened the Technical Committee Meeting on ''Materials Reliability in the Back-End of the Nuclear Fuel Cycle'' at its Headquarters from September 2 to 5, 1986. This Technical Document contains the 15 papers presented during the Meeting. Material aspects of the following fields of the back-end of the nuclear fuel cycle are covered: interim and long-term storage of spent fuel; final disposal of spent fuel; storage and vitrification of High Level Liquid Wastes (HLLW); long-term storage of High Level Wastes (HLW); and spent fuel treatment

Back end of the nuclear fuel cycle

International Nuclear Information System (INIS)

Shapar, H.K.

1986-01-01

Most of the nuclear spent fuel that is discharged from the reactors in OECD countries is destined currently for long term interim storage before final processing or direct disposal. There are at least three basic considerations affecting the dicision on spent fuel, that is, the capacity of prompt reprocessing is insufficient at present, reprocessing is not urgent for the reason of economy or plutonium availability, and the cooling of spent fuel in controlled storage is economically advantageous. The basic technology of reprocessing has been commercially available for several decades, but political problems and the lack of immediate incentive for reprocessing slowed the buildup of new capacity. To avoid the problems related to plutonium storage, it is reasonable to postpone reprocessing. Some OECD countries plan the direct disposal of spent fuel elements instead of reprocessing. The technology, supply and demand and cost of the storage and transport of spent fuel, reprocessing and waste disposal are discussed. The share of the back end in the total levelized fuel cycle cost is expected to be between 10 and 20 %. The impact of the choice of back end options on the cost of power generation will be only 2 %. (Kako, I.)

Nuclear Fuel Cycle Strategy For Developing Countries

International Nuclear Information System (INIS)

Kim, Chang Hyo

1987-01-01

The world's uranium market is very uncertain at the moment while other front-end fuel cycle services including enrichment show a surplus of supply. Therefore, a current concern of developing countries is how to assure a long-term stable supply of uranium, so far as front-end fuel cycle operation is concerned. So, as for the front-end fuel cycle strategy, I would like to comment only on uranium procurement strategy. I imagine that you are familiar with, yet let me begin my talk by having a look at, the nuclear power development program and current status of fuel cycle technology of developing countries. It is a nice thing to achieve the full domestic control of fuel cycle operation. The surest way to do so is localization of related technology. Nevertheless, developing at a time due to enormous capital requirements, not to mention the non-proliferation restrictions. Therefore, the important which technology to localize prior to other technology and how to implement. The non-proliferation restriction excludes the enrichment and reprocessing technology for the time being. As for the remaining technology the balance between the capital costs and benefits must dictate the determination of the priority as mentioned previously. As a means to reduce the commercial risk and heavy financial burdens, the multi-national joint venture of concerned countries is desirable in implementing the localization projects

End-Users, Front Ends and Librarians.

Science.gov (United States)

Bourne, Donna E.

1989-01-01

The increase in end-user searching, the advantages and limitations of front ends, and the role of the librarian in end-user searching are discussed. It is argued that librarians need to recognize that front ends can be of benefit to themselves and patrons, and to assume the role of advisors and educators for end-users. (37 references) (CLB)

Welding nuclear reactor fuel rod end plugs

International Nuclear Information System (INIS)

Yeo, D.

1984-01-01

Apparatus for applying a vacuum to a nuclear fuel rod cladding tube's interior through its open end while girth welding an inserted end plug to its other end. An airtight housing has an orifice with a seal which can hermetically engage the tube's open end. A vacuum hose has one end connected to the housing and the other end connected to a vacuum pump. A mechanized device which moves the housing to engage or disengage its seal with the tube's open end includes at least one arm having one end attached to the housing and the other end pivotally attached to a movable table; an arm rotating device to coaxially align the housing's orifice with the welding-positioned tube; and a table moving device to engage the seal of the coaxially aligned orifice with the tube's open end. (author)

Romanian nuclear fuel cycle development

International Nuclear Information System (INIS)

Rapeanu, S.N.; Comsa, Olivia

1998-01-01

Romanian decision to introduce nuclear power was based on the evaluation of electricity demand and supply as well as a domestic resources assessment. The option was the introduction of CANDU-PHWR through a license agreement with AECL Canada. The major factors in this choice have been the need of diversifying the energy resources, the improvement the national industry and the independence of foreign suppliers. Romanian Nuclear Power Program envisaged a large national participation in Cernavoda NPP completion, in the development of nuclear fuel cycle facilities and horizontal industry, in R and D and human resources. As consequence, important support was being given to development of industries involved in Nuclear Fuel Cycle and manufacturing of equipment and nuclear materials based on technology transfer, implementation of advanced design execution standards, QA procedures and current nuclear safety requirements at international level. Unit 1 of the first Romanian nuclear power plant, Cernavoda NPP with a final profile 5x700 Mw e, is now in operation and its production represents 10% of all national electricity production. There were also developed all stages of FRONT END of Nuclear Fuel Cycle as well as programs for spent fuel and waste management. Industrial facilities for uranian production, U 3 O 8 concentrate, UO 2 powder and CANDU fuel bundles, as well as heavy water plant, supply the required fuel and heavy water for Cernavoda NPP. The paper presents the Romanian activities in Nuclear Fuel Cycle and waste management fields. (authors)

Analysis of factors affecting the implementation of back-end nuclear fuel cycle policy in Korea

International Nuclear Information System (INIS)

Choi, Yung Myung; Yang, Maeng Ho; Kim, Hyun Joon; Chung, Hwan Sam; Oh, Keun Bae; Lee, Byung OoK; Ko, Han Suk; Song, Ki Dong; Lee, Man Ki; Moon, Ki Hwan; Lee, Han Myung

1994-01-01

In this study, the back-end nuclear fuel cycle acceptability is surveyed and analyzed in the following three aspects. To begin with, the future political situation and energy-environmental issues are analyzed as part of the socio-economic aspect. Secondly, the domestic situation of nuclear industries and the fuel cycle policy of foreign countries are surveyed as the technical aspect. Finally, NPT, IAEA safeguards and nuclear export control regimes are analyzed as the institutional aspect. The unification period of South and North Korea also will greatly affect the implementation of back-end fuel cycle policy, and public attitudes will affect the acquisition of site, construction, and operation of nuclear facilities. An effort to release international restrictions on the back-end fuel cycle is also required to accelerate the implementation of the policy. In this regard, the back-end fuel cycle policy should be clear-cut to avoid misunderstanding with respect to nuclear proliferation. Importantly, agreements with foreign countries should be amended at a mutual equivalent level. (Author) 30 refs., 5 figs., 25 tabs

Analysis of factors affecting the implementation of back-end nuclear fuel cycle policy in Korea

Energy Technology Data Exchange (ETDEWEB)

Choi, Yung Myung; Yang, Maeng Ho; Kim, Hyun Joon; Chung, Hwan Sam; Oh, Keun Bae; Lee, Byung OoK; Ko, Han Suk; Song, Ki Dong; Lee, Man Ki; Moon, Ki Hwan; Lee, Han Myung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-01-01

In this study, the back-end nuclear fuel cycle acceptability is surveyed and analyzed in the following three aspects. To begin with, the future political situation and energy-environmental issues are analyzed as part of the socio-economic aspect. Secondly, the domestic situation of nuclear industries and the fuel cycle policy of foreign countries are surveyed as the technical aspect. Finally, NPT, IAEA safeguards and nuclear export control regimes are analyzed as the institutional aspect. The unification period of South and North Korea also will greatly affect the implementation of back-end fuel cycle policy, and public attitudes will affect the acquisition of site, construction, and operation of nuclear facilities. An effort to release international restrictions on the back-end fuel cycle is also required to accelerate the implementation of the policy. In this regard, the back-end fuel cycle policy should be clear-cut to avoid misunderstanding with respect to nuclear proliferation. Importantly, agreements with foreign countries should be amended at a mutual equivalent level. (Author) 30 refs., 5 figs., 25 tabs.

Safety aspects of front-end fuel cycle facilities

International Nuclear Information System (INIS)

Srinivasan, G.R.

2003-01-01

Safety of fuel cycle facilities (FCFs) other than Nuclear Power Plants is gaining importance all over the nuclear world as one would not like to leave behind any area of nuclear field in the journey toward excellence in the safe conduct of business in the whole of the nuclear industry. Safety should be part of every day activities, procedures, business practices, system and in fact of the people themselves

Grapples for manipulating end fittings for nuclear reactor fuel assemblies

International Nuclear Information System (INIS)

Jabsen, F.S.

1982-01-01

A nuclear fuel assembly includes control rod guide tubes the upper ends of which protrude beyond a spider and are locked in place by means of a cellular lattice seated in grooves in the outer surfaces of the sleeves. A grapple is provided for disengaging the structure comprising lattice, spider, springs and a grill from the end of the fuel assembly to enable these components to be removed in an assembly state and subsequently replaced after inspection and repair. (author)

Fuel cycle management by the electric enterprises and spanish nuclear Power plants; Gestion del ciclo de combustible por las empresas electricas y centrales nucleares espanolas

Energy Technology Data Exchange (ETDEWEB)

Celma, E. M.; Gonzalez, C.; Lopez, J. V.; Melara, J.; Lopez, L.; Martinez, J. C.; Culbras, F.; Blanco, J.; Francia, L.

2015-07-01

The Nuclear Fuel Group reports to the Technology Committee of the UNESA Nuclear Energy Committee, and is constituted by representatives of both the Spanish Utilities and the Nuclear Power Plants. The Group addresses the nuclear plant common issues in relation to the operation and management of the nuclear fuel in their different stages of the Fuel Cycle. The article reviews the activities developed by the Group in the Front-End, mainly in the monitoring of international programs that define criteria to improve the Fuel Reliability and in the establishment of common bases for the implementation of changes in the regulation applying the nuclear fuel. Concerning the Back-End the Group focuses on those activities of coordination with third parties related to the management of used fuel. (Author)

Regulation at nuclear fuel cycle

International Nuclear Information System (INIS)

2002-01-01

This bulletin contains information about activities of the Nuclear Regulatory Authority of the Slovak Republic (UJD). In this leaflet the role of the UJD in regulation at nuclear fuel cycle is presented. The Nuclear Fuel Cycle (NFC) is a complex of activities linked with production of nuclear fuel for nuclear reactors as a source of energy used for production of electricity and heat, and of activities linked with spent nuclear fuel handling. Activities linked with nuclear fuel (NF) production, known as the Front-End of Nuclear Fuel Cycle, include (production of nuclear fuel from uranium as the most frequently used element). After discharging spent nuclear fuel (SNF) from nuclear reactor the activities follow linked with its storage, reprocessing and disposal known as the Back-End of Nuclear Fuel Cycle. Individual activity, which penetrates throughout the NFC, is transport of nuclear materials various forms during NF production and transport of NF and SNF. Nuclear reactors are installed in the Slovak Republic only in commercial nuclear power plants and the NFC is of the open type is imported from abroad and SNF is long-term supposed without reprocessing. The main mission of the area of NFC is supervision over: - assurance of nuclear safety throughout all NFC activities; - observance of provisions of the Treaty on Non-Proliferation of Nuclear Weapons during nuclear material handling; with an aim to prevent leakage of radioactive substances into environment (including deliberated danage of NFC sensitive facilities and misuse of nuclear materials to production of nuclear weapons. The UJD carries out this mission through: - assessment of safety documentation submitted by operators of nuclear installations at which nuclear material, NF and SNF is handled; - inspections concentrated on assurance of compliance of real conditions in NFC, i.e. storage and transport of NF and SNF; storage, transport and disposal of wastes from processing of SNF; with assumptions of the safety

OECD/NEA Ongoing activities related to the nuclear fuel cycle

International Nuclear Information System (INIS)

Cornet, S.M.; McCarthy, K.; Chauvin, N.

2013-01-01

As part of its role in encouraging international collaboration, the OECD Nuclear Energy Agency is coordinating a series of projects related to the Nuclear Fuel Cycle. The Nuclear Science Committee (NSC) Working Party on Scientific Issues of the Nuclear Fuel Cycle (WPFC) comprises five different expert groups covering all aspects of the fuel cycle from front to back-end. Activities related to fuels, materials, physics, separation chemistry, and fuel cycles scenarios are being undertaken. By publishing state-of-the-art reports and organizing workshops, the groups are able to disseminate recent research advancements to the international community. Current activities mainly focus on advanced nuclear systems, and experts are working on analyzing results and establishing challenges associated to the adoption of new materials and fuels. By comparing different codes, the Expert Group on Advanced Fuel Cycle Scenarios is aiming at gaining further understanding of the scientific issues and specific national needs associated with the implementation of advanced fuel cycles. At the back end of the fuel cycle, separation technologies (aqueous and pyrochemical processing) are being assessed. Current and future activities comprise studies on minor actinides separation and post Fukushima studies. Regular workshops are also organized to discuss recent developments on Partitioning and Transmutation. In addition, the Nuclear Development Committee (NDC) focuses on the analysis of the economics of nuclear power across the fuel cycle in the context of changes of electricity markets, social acceptance and technological advances and assesses the availability of the nuclear fuel and infrastructure required for the deployment of existing and future nuclear power. The Expert Group on the Economics of the Back End of the Nuclear Fuel Cycle (EBENFC), in particular, is looking at assessing economic and financial issues related to the long term management of spent nuclear fuel. (authors)

Nuclear fuel supply: challenges and opportunities

International Nuclear Information System (INIS)

Lowen, S.

2006-01-01

Prices of uranium, conversion services and enrichment services have all significantly increased in the last few years. These price increases have generally been driven by a tightening in the supply of these products and services, mostly due to long lead times required to bring these products and services to the market. This paper will describe the various steps in the nuclear fuel cycle for natural and enriched uranium fuel, will discuss the development of the front-end fuel cycle for low void reactivity fuel, and will address the challenges faced in the long-term supply of each component, particularly in the light of potential demand increases as a result of a nuclear renaissance. The opportunities for new capacity and uranium production will be outlined and the process required to achieve sufficient new supply will be discussed. (author)

Nuclear reactor fuel assemblies and end fitting grid structures therefor

International Nuclear Information System (INIS)

Jabsen, F.S.

1978-01-01

An improved end fitting grid structure is described for nuclear fuel assemblies which overcomes the need for load-bearing control rod guide tubes and the expensive special fittings that these tubes required. (UK)

Pyrochemical head-end treatment for spent nuclear fuels

International Nuclear Information System (INIS)

Bowersox, D.F.

1977-01-01

A program based upon thermodynamic values and scouting experiments at Argonne National Laboratory is proposed for development of a pyrochemical head-end treatment of spent nuclear fuels to replace the proposed chopping and leaching operation in the Purex process. The treatment consists of separation of the cladding from the oxide fuel by dissolution into liquid zinc; oxide reduction of uranium and plutonium and dissolution into a zinc--magnesium alloy; separation of alkali, alkaline earth, and rare earth fission products into a molten salt; and, finally, separation and recovery of the plutonium and uranium in the alloy. Uranium and plutonium would be separated from the fuel cladding and selected fission products in a form readily dissolvable in nitric acid. The head-end process could be developed eventually into an optimum method for recovering uranium, plutonium, and selected fission products and for minimizing wastes as compact, stable solids. Developmental expenses are not known clearly, but the potential advantages of the process are impressive

IAEA activities in the back-end area of nuclear fuel cycle

International Nuclear Information System (INIS)

Fukuda, Kosaku

1999-01-01

This paper concerns recent outcomes from the IAEA's activities in the area of the nuclear fuel cycle, particularly focusing on the back-end of the fuel cycle. It includes spent fuel management, plutonium utilization and burnup credit. In the area of spent fuel management, worldwide prospects and status of the spent fuel arising, storage and reprocessing are presented. In the area of plutonium utilization worldwide, only MOX fuel fabrication is described. Finally, the worldwide status of the burnup credit implementation is described. (author)

The strategy of the long-term back-end nuclear fuel cycle in the Czech Republic

International Nuclear Information System (INIS)

Palagyi, S.; Fajman, V.

2002-01-01

The present status of the strategy of the long-term back-end nuclear fuel cycle in the Czech Republic is briefly outlined in this paper. This strategy is based on the once-through option in the use of the nuclear fuel with subsequent interim storage of the spent fuel and its final disposal as a declared high level waste. However, other technologies for the management of the back-end of the nuclear fuel cycle are not excluded at all. Besides the first already existing and the second interim spent fuel storage facility being sited at Dukovany Nuclear Power Plant, an interim spent fuel storage facility at Temelin Nuclear Power Plant is also under the siting process. To cover the total storing needs a central spent nuclear fuel interim storage facility at Skalka in the Czech-Moravian Highlands is also under consideration. These facilities are or will be equipped with dry-storage containers of cask-type placed in the concrete building and cooled by natural air ventilation. Since 1993 there is a joint effort of several governmental organisations and institutions and private companies to study the scientific, technical and economical possibilities of the construction of the deep geological repository for spent nuclear fuel disposal. A horizontal repository facility with vertical access was selected and a reference project has been accepted. A time horizon for construction in about the year of 2035 was scheduled. The necessary legal and administrative basis of the spent fuel and radioactive waste management was laid down by the law No. 18/1997 (Atomic Act) passed in 1997. This basic law with its implementing regulations fully reflects the internationally accepted principles of the provision of nuclear safety and radiation protection in this respect and it also strongly supports the policy and strategy of the back-end of the nuclear fuel cycle. (author)

Factors determining the long term back end nuclear fuel cycle strategy and future nuclear systems. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

2002-05-01

The Technical Committee Meeting (TCM) was held in Vienna on 8-10 November 1999; it was organized by the International Atomic Energy Agency and attended by 26 participants from 16 Member States. The purpose of the meeting was to exchange information among experts on the back end fuel cycle strategies adopted by Member States; to identify key factors determining the long-term back end fuel cycle strategies; and to assess the applicability of these factors to future nuclear systems. Issues associated with the back end fuel cycle supporting a country's nuclear power programme are technical, economic, institutional and political. This TCM provided an opportunity to address these issues and their impacts to the back end fuel cycles, as well as to identify and assess factors affecting the back end fuel cycle strategies. The discussion was organized ib the following topical sessions: the nuclear fuel cycle; spent fuel management; waste management and repository; plutonium management. This document contains a summary of the meeting and 22 individual papers presented by participants. Each of the papers was indexed separately

Factors determining the long term back end nuclear fuel cycle strategy and future nuclear systems. Proceedings of a technical committee meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-05-01

The Technical Committee Meeting (TCM) was held in Vienna on 8-10 November 1999; it was organized by the International Atomic Energy Agency and attended by 26 participants from 16 Member States. The purpose of the meeting was to exchange information among experts on the back end fuel cycle strategies adopted by Member States; to identify key factors determining the long-term back end fuel cycle strategies; and to assess the applicability of these factors to future nuclear systems. Issues associated with the back end fuel cycle supporting a country's nuclear power programme are technical, economic, institutional and political. This TCM provided an opportunity to address these issues and their impacts to the back end fuel cycles, as well as to identify and assess factors affecting the back end fuel cycle strategies. The discussion was organized ib the following topical sessions: the nuclear fuel cycle; spent fuel management; waste management and repository; plutonium management. This document contains a summary of the meeting and 22 individual papers presented by participants. Each of the papers was indexed separately.

Interim transfer canister for consolidating nuclear fuel rods

International Nuclear Information System (INIS)

Formanek, F.J.

1987-01-01

This patent describes a canister for receiving and consolidating a group of uniformly spaced apart nuclear fuel rods, comprising: a rectangular, vertically oriented straight back panel; a pair of oppositely disposed side panels connected perpendicularly to the back panel, having a vertical straight upper portion and an inwardly tapered lower portion; a front panel opposite the back panel and connected to the side panels, having a straight vertical upper portion and inwardly tapered lower portion; whereby the back, side and front panels define a rectangular upper opening at the upper end of the canister and a generally rectangular lower opening at the other end, the lower opening having a cross-sectional area less than one-half that of the upper opening; parallel plate members spanning the canister from the front panel to the back panel, each plate spaced from the other the same uniform distance, the plates extending downwardly into the tapered portion of the canister while remaining spaced above the tapered sidewalls; first base means at the lower end of the canister, removably mounted and having an oblique orientation generally downward from the front panel to the back panel, for guiding the fuel rods to be inserted preferentially toward the lower portion of the back panel; and second base means removably mounted within the canister below first base means and oriented transversely to the longitudinal extent of the canister, for supporting the fuel rods when the first base means is removed from the canister

Nuclear fuel element end fitting

International Nuclear Information System (INIS)

Jabsen, F.S.

1980-01-01

An invention is described whereby end fittings are formed from lattices of mutually perpendicular plates. At the plate intersections, sockets are secured to the end fittings in a manner that permits the longitudinal axes of each of the sockets to align with the respective lines of intersection of the plates. The sockets all protrude above one of the surfaces of the end fitting. Further, a detent is formed in the proturding sides of each of the sockets. Annular grooves are formed in each of the ends of the fuel rods that are to be mounted between the end fittings. The socket detents protrude into the respective annular grooves, thus engaging the grooves and retaining the fuel rods and end fittings in one integral structure. (auth)

Multilateral approaches to the nuclear fuel cycle. Expert group report to the Director General of the IAEA

International Nuclear Information System (INIS)

2005-04-01

An international expert group has been appointed to consider options for possible multilateral approaches to the nuclear fuel cycle. The terms of reference for the Expert Group were to: 1)Identify and provide an analysis of issues and options relevant to multilateral approaches to the front and back ends of the nuclear fuel cycle; 2)Provide an overview of the policy, legal, security, economic and technological incentives and disincentives for cooperation in multilateral arrangements for the front and back ends of the nuclear fuel cycle; and 3)Provide a brief review of the historical and current experience in this area, and of the various analyses relating to multilateral fuel cycle arrangements relevant to the work of the Expert Group. The Group examined the nuclear fuel cycle and multinational approaches at meetings convened over a seven month period. Their report, presented in the paper, was released on 22 February 2005, and circulated for discussion among the IAEA Member States, as well as others, as an IAEA Information Circular (INFCIRC/640)

Nuclear reactor fuel element containing an end piece for maintaining the column of fuel pellets

International Nuclear Information System (INIS)

Pajot, Jacques; Rabellino, Jacques.

1974-01-01

The nuclear reactor fuel element described has an end piece for maintaining the column of fuel pellets in position inside the element cladding. This end piece has a central compression spring one end of which presses against the pellets and the other against a plug shaped piece fitted with a seat for the spring, a conical piece with an elastic ring around it diverging towards the end in contact with the spring and a head at the opposite end. The connection between the compression spring and the pellets is through an application piece. A central bore provided in the end piece helps balance the pressure inside the element. This element is particularly intended for liquid metal cooled fast neutron reactors [fr

Multilateral approach to the back end of the nuclear fuel cycle in Asia-Pacific?

International Nuclear Information System (INIS)

Lim, Eunjung

2016-01-01

In spite of the nearly unprecedented scale of the Fukushima Daiichi Nuclear Accident which caused countries around the world to review their nuclear power systems and to rethink their nuclear power expansion plans, nuclear power capacity continues to grow, spearheaded by the Asia-Pacific region. The Asia-Pacific has become a major emerging market for nuclear energy industry, which indicates that the management of spent nuclear fuel is likely to be a nuisance for the countries in this region in the coming decades. By reviewing the history of discussions on multilateral approaches to the back end of the nuclear fuel cycle and examining relevant empirical cases, this article aims to explore the feasibility of a multilateral approach to the back end of the nuclear fuel cycle in this region and provide some policy suggestions to enhance nuclear governance in the Asia-Pacific. - Highlights: • The Asia-Pacific has become a huge emerging market for nuclear power industry. • Asian-Pacific countries operating reactors lack solution for spent nuclear fuel. • Multilateral approach is attractive, but hard to be realized. • The main obstacle is variations in policies for SNF management among the Asia-Pacific countries. • The country that should take its initiative in this field is the United States.

Assessment of radiological and non-radiological hazards in the nuclear fuel cycle - The Indian experience

International Nuclear Information System (INIS)

Krishnamony, S.; Gopinath, D.V.

1996-01-01

Design and operational aspects of nuclear fuel cycle facilities have several features that distinguish them from nuclear power plants. These are related to (i) the nature of operations which are chiefly mining, metallurgical and chemical; (ii) the nature and type of radio-active materials handled, their specific activities and inventories; and (iii) the physical and chemical processes involved and the associated containment provisions. Generally the radioactive materials are present in an already highly dispersible or mobile form, in the form of solutions, slurries and powders, often associated with a wide variety of reactive and corrosive chemicals. There are further marked differences between the front-end and back-end of the fuel cycle. Whereas the front-end is characterized by the presence of large quantities of low specific activity naturally occurring radioactive materials, the back-end is characterized by high specific activities and concentrations of fission products and actinides. Radioactive characteristics of waste arisings are also different in different phases of the nuclear fuel cycle. Potential for internal exposure in the occupational environment is another distinguishing feature as compared with the more common designs of nuclear power reactors. Potential for accidents, their phenomenology and the resulting consequences are also markedly different in fuel cycle operations. The non-radiological hazards in fuel cycle operations are also of significance, since the operations are mostly mining, metallurgical and chemical in nature. These aspects are examined and evaluated in this paper, based on the Indian experience. (author). 12 refs, 10 tabs

Apparatus for inspecting the quality of nuclear fuel rod ends

International Nuclear Information System (INIS)

Brashier, R.W.; Pfau, E.D.

1990-01-01

This patent describes an apparatus for inspecting the quality of both ends of nuclear fuel rods. It comprises: a housing including a pair of longitudinally separated slots for receiving X-ray downwardly therethrough from an external source and so as to define first and second longitudinally spaced apart operating positions, means for serially guiding nuclear fuel rods longitudinally through the housing and to a first rod position wherein the forward ends of the rods are aligned below the first operating position and to a second rod position wherein the rear ends of the rods are aligned below the second operating position, belt conveyor assembly means for serially advancing X-ray film cartridges longitudinally through the housing and below the rods, and so that each cartridge may be selectively aligned below the first and second operating positions; and table means supported by the conveyor frame for selectively lifting the film cartridges supported by the belts and so that the conveyor belts may be advanced while the film cartridges are held stationary

The Back End of the Fuel Cycle Moves Front and Center

International Nuclear Information System (INIS)

Isaacs, T; Choi, J

2006-01-01

For many years, the commercial nuclear business has remained relatively stable in many ways. The introduction of new plants, the spread to new countries, and the development of key elements of the fuel cycle such as enrichment, reprocessing and waste disposal have been quite modest. That is unlikely to be the case in the coming years. A number of events and trends are becoming increasingly apparent and are cause for both opportunity and caution: (1) New nuclear power plant orders are likely to grow and spread, particularly in the developing world, e.g. China and India. (2) The growing recognition that the developing world will be a major competitor for limited energy resources is raising awareness in the developed world regarding concerns for future energy security. (3) Clearer evidence of the effects of greenhouse gas emissions on global warming, largely from the burning of fossil fuels, is creating more attention on the environmental benefits of nuclear power. (4) The last decade has shown unequivocal evidence of countries lying, cheating on their NPT obligation, and covertly carrying out nuclear weapons-related activities. Some have suggested their presumed need for a domestic nuclear fuel cycle as a rationale to pursue enrichment and/or reprocessing capabilities, which would move them to the doorstep of being nuclear weapons capable. The DPRK even took the action to abrogate the NPT to hold on to its nuclear weapons program. (5) 9/11 and other evidence have made it undeniable that terrorist groups would like to obtain weapons of mass destruction, particularly nuclear weapons, and would use them if they could. A number of initiatives have been proposed recently to allow for the growth and spread of nuclear power while limiting the justifications for additional countries to pursue the acquisition of enrichment or reprocessing capabilities. Most of these initiatives have fresh fuel assurance as a central component. The rationale is simple; if a country can have

Nuclear energy technology: theory and practice of commercial nuclear power

International Nuclear Information System (INIS)

Knief, R.A.

1982-01-01

Reviews Nuclear Energy Technology: Theory and Practice of Commercial Nuclear Power by Ronald Allen Knief, whose contents include an overview of the basic concepts of reactors and the nuclear fuel cycle; the basics of nuclear physics; reactor theory; heat removal; economics; current concerns at the front and back ends of the fuel cycle; design descriptions of domestic and foreign reactor systems; reactor safety and safeguards; Three Mile Island; and a brief overview of the basic concepts of nuclear fusion. Both magnetic and inertial confinement techniques are clearly outlined. Also reviews Nuclear Fuel Management by Harry W. Graves, Jr., consisting of introductory subjects (e.g. front end of fuel cycle); core physics methodology required for fuel depletion calculations; power capability evaluation (analyzes physical parameters that limit potential core power density); and fuel management topics (economics, loading arrangements and core operation strategies)

Uranium for Nuclear Power: Resources, Mining and Transformation to Fuel

International Nuclear Information System (INIS)

Hore-Lacy, Ian

2016-01-01

Uranium for Nuclear Power: Resources, Mining and Transformation to Fuel discusses the nuclear industry and its dependence on a steady supply of competitively priced uranium as a key factor in its long-term sustainability. A better understanding of uranium ore geology and advances in exploration and mining methods will facilitate the discovery and exploitation of new uranium deposits. The practice of efficient, safe, environmentally-benign exploration, mining and milling technologies, and effective site decommissioning and remediation are also fundamental to the public image of nuclear power. This book provides a comprehensive review of developments in these areas: • Provides researchers in academia and industry with an authoritative overview of the front end of the nuclear fuel cycle • Presents a comprehensive and systematic coverage of geology, mining, and conversion to fuel, alternative fuel sources, and the environmental and social aspects • Written by leading experts in the field of nuclear power, uranium mining, milling, and geological exploration who highlight the best practices needed to ensure environmental safety

Internationalization of the back end of the nuclear fuel cycle: Problems and prospects

International Nuclear Information System (INIS)

Haeckel, E.

1997-01-01

International cooperation and transnational division of labour is a distinctive feature of the nuclear industry, but it is conspicuously lacking at the back end of the nuclear fuel cycle. Meanwhile, national efforts to close the fuel cycle have remained largely unsuccessful. Governments and the nuclear industry are paralyzed in a gridlock of indecision and obstruction. This pattern has been reinforced at the international level. More recently, however, a number of dynamic challenges to governments and the industry has opened up new prospects for internationalization. (author)

Internationalization of the back end of the nuclear fuel cycle: Problems and prospects

Energy Technology Data Exchange (ETDEWEB)

Haeckel, E [Forschunginstitut der Deutschen Gesellschaft fuer Auswaertige Politik, Bonn (Germany)

1997-12-01

International cooperation and transnational division of labour is a distinctive feature of the nuclear industry, but it is conspicuously lacking at the back end of the nuclear fuel cycle. Meanwhile, national efforts to close the fuel cycle have remained largely unsuccessful. Governments and the nuclear industry are paralyzed in a gridlock of indecision and obstruction. This pattern has been reinforced at the international level. More recently, however, a number of dynamic challenges to governments and the industry has opened up new prospects for internationalization. (author). 3 refs.

Overview of the OECD Nuclear Energy Agency scientific activities on the nuclear fuel cycle - 5301

International Nuclear Information System (INIS)

Cornet, S.; Chauvin, N.

2015-01-01

As part of its role in encouraging international collaboration, the OECD Nuclear Energy Agency is coordinating a series of projects related to the Nuclear Fuel Cycle. The Nuclear Science Committee (NSC) Working Party on Scientific Issues of the Nuclear Fuel Cycle (WPFC) comprises five different expert groups covering scientific aspects of the fuel cycle from front to back-end. Ongoing projects include fuel cycle scenarios, fuels, materials, physics and chemical separations. Members of the expert groups cooperate to share recent research advancements at an international level and help identify gaps and needs in the field. Current activities focus on current and advanced nuclear systems in particular the challenges associated with the adoption of new materials and fuels such as for example cladding materials, fuels containing minor actinides, or the use of liquid metal as coolants. The Expert Group on Innovative Fuels has recently prepared a report on MA bearing fuels looking at different type of fuels and examining the technical issues associated with their fabrication, characterization, irradiation performance, and design and safety criteria. Experts of the group on Heavy Liquid Metal (HLM) technologies are compiling and editing the second version of the LBE (Lead Bismuth Eutectic) Handbook to include new experimental data. The Expert Group on Advanced Fuel Cycle Scenarios has undertaken a study to evaluate the effects of uncertainties of input parameters on the outcomes of fuel scenario studies to provide guidance on which uncertainties are more significant. At the back-end of the fuel cycle, separation technologies (aqueous and pyrochemical) are being assessed by the Expert Group on Fuel recycling Chemistry. (authors)

Nuclear fuels

International Nuclear Information System (INIS)

Gangwani, Saloni; Chakrabortty, Sumita

2011-01-01

Nuclear fuel is a material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned for energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials. Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different. The following paper will also include the uses. advancements, advantages, disadvantages, various processes and behavior of nuclear fuels

Impact of political and legislative events on the front end of the fuel cycle

International Nuclear Information System (INIS)

Steyn, J.J.

1987-01-01

This paper examines recent political and legislative events in the U.S. which could impact the supply of natural uranium, uranium hexafluoride, conversion services, and uranium enrichment services. While the industry has been clouded with continuing uncertainty resulting from the ongoing miners vs. DOE litigation and a number of legislative proposals to embargo the import of uranium, very little attention was being paid to the free trade agreement discussions which were taking place between the U.S. and Canada. However, with a draft agreement now being fact and its ratification a possibility by mid-1988, the front end of the fuel cycle may finally begin to achieve some normalcy within the next year. The impact of these factors on the industry are addressed

Nuclear fuel elements

International Nuclear Information System (INIS)

Nakai, Keiichi

1983-01-01

Purpose: To decrease the tensile stresses resulted in a fuel can as well as prevent decladding of fuel pellets into the bore holes by decreasing the inner pressure within the nuclear fuel element. Constitution: A fuel can is filled with hollow fuel pellets, inserted with a spring for retaining the hollow fuel pellets with an appropriate force and, thereafter, closely sealed at the both ends with end plugs. A cylindrical body is disposed into the bore holes of the hollow fuel pellets. Since initial sealing gases and/or gaseous nuclear fission products can thus be excluded from the bore holes where the temperature is at the highest level, the inner pressure of the nuclear fuel element can be reduced to decrease the tensile strength resulted to the fuel can. Furthermore, decladding of fuel pellets into the bore holes can be prevented. (Moriyama, K.)

The back end of the nuclear fuel cycle: technical and economic analysis-Part 1

International Nuclear Information System (INIS)

Roglans-Ribas, J.; Spinrad, B.I.

1990-01-01

The back end of the nuclear fuel cycle has been analyzed under current conditions in the United States, taking into consideration the framework defined by the Nuclear Waste Policy Act of 1982 and its amendments. The different steps of the back end of the fuel cycle are studied and different alternatives are compared under technical and economic criteria. Several technical issues have been analyzed for their impact on the economics of the fuel cycle. The bases for the analysis are explained, and the results for a once-through cycle are presented. The results show that a repository in tuff represents the minimum cost situation. The economic model appears very sensitive to several parameters, in particular the period of retrievability and the storage costs

Apparatus and method for applying an end plug to a fuel rod tube end

International Nuclear Information System (INIS)

Rieben, S.L.; Wylie, M.E.

1987-01-01

An apparatus is described for applying an end plug to a hollow end of a nuclear fuel rod tube, comprising: support means mounted for reciprocal movement between remote and adjacent positions relative to a nuclear fuel rod tube end to which an end plug is to be applied; guide means supported on the support means for movement; and drive means coupled to the support means and being actuatable for movement between retracted and extended positions for reciprocally moving the support means between its respective remote and adjacent positions. A method for applying an end plug to a hollow end of a nuclear fuel rod tube is also described

Proceedings of the 2007 LWR Fuel Performance Meeting / TopFuel 2007 'Zero by 2010'

International Nuclear Information System (INIS)

2007-01-01

ANS, ENS, AESJ and KNS are jointly organizing the 2007 International LWR Fuel Performance Meeting following the successful ENS TopFuel meeting held during 22-26 October, 2006 in Salamaca, Spain. Merging three premier nuclear fuel design and performance meetings: the ANS LWR Fuel Performance Meeting, the ENS TopFuel and Asian Water Reactor Fuel Performance Meeting (WRFPM) created this international meeting. The meeting will be held annually on a tri-annual rotational basis in USA, Asia, and Europe. The technical scope of the meeting includes all aspects of nuclear fuel from fuel rod to core design as well as performance experience in commercial and test reactors. The meeting excludes front end and back end fuel issues, however, it covers all front and/or back issues that impact fuel designs and performance

Factors determining the UK's back-end nuclear fuel cycle strategy and future nuclear systems

International Nuclear Information System (INIS)

Dunn, M.J.; Ainsworth, Z.E.

2002-01-01

Nuclear generating capacity in the UK is static with no units currently under construction. The AGRs and the UK's only PWR, Sizewell B, are operated by British Energy Generation Ltd (BEGL) and British Energy Generation (UK) Ltd (BEG(UK)L), who are subsidiaries of British Energy plc (BE) which was privatised in July 1996. Ownership of the Magnox stations, which were excluded from this privatisation, has now been transferred to BNFL.Government policy on spent fuel management in the UK is that it is for the owners of the spent fuel to decide on the appropriate spent fuel management options, based on their own commercial judgement, subject to meeting the necessary regulatory requirements. The main factors which have predominantly determined UK utility decisions on spent fuel management, to date, have been based on the technical considerations of the spent fuel characteristics, economic attractiveness of the options and at reactor site spent fuel storage capacities. To date, reprocessing has been the dominant form of spent fuel treatment in the UK. Spent fuel storage facilities consist of a mixture of at-reactor stores and large, centralised ponds associated with the reprocessing activities which take place at the Sellafield site. BEGL and BEG(UK)L have contracts for the lifetime arisings of AGR fuel which allow for all AGR spent fuel to be sent to Sellafield for reprocessing or long-term storage. The prompt reprocessing of all Magnox fuel will continue, and spent PWR fuel will continue to be stored at the reactor site in the short to medium term. It is likely that a combination of factors, which are discussed later in this paper, will continue to affect back-end nuclear fuel cycle strategy and future nuclear systems. (author)

Nuclear fuel and energy policy

International Nuclear Information System (INIS)

Ahmed, S.B.

1979-01-01

This book examines the uranium resource situation in relation to the future needs of the nuclear economy. Currently the United States is the world's leading producer and consumer of nuclear fuels. In the future US nuclear choices will be highly interdependent with the rest of the world as other countries begin to develop their own nuclear programs. Therefore the world's uranium resource availability has also been examined in relation to the expected growth in the world nuclear industry. Based on resource evaluation, the study develops an economic framework for analyzing and describing the behavior of the US uranium mining and milling industry. An econometric model designed to reflect the underlying structure of the physical processes of the uranium mining and milling industry has been developed. The purpose of this model is to forecast uranium prices and outputs for the period 1977 to 2000. Because uncertainty has sometimes surrounded the economic future of the uranium markets, the results of the econometric modeling should be interpreted with great care and restrictive assumptions. Another aspect of this study is to provide much needed information on the operations of government-owned enrichment plants and the practices used by the government in the determination of fuel enrichment costs. This study discusses possible future developments in enrichment supply and technologies and their implications for future enrichment costs. A review of the operations involving the uranium concentrate conversion to uranium hexafluoride and fuel fabrication is also provided. An economic analysis of these costs provides a comprehensive view of the front-end costs of the nuclear fuel cycle

Nuclear fuel pellet charging device

International Nuclear Information System (INIS)

Komuro, Kojiro.

1990-01-01

The present invention concerns a nuclear fuel pellet loading device, in which nuclear fuel pellets are successively charged from an open end of a fuel can while rotating the can. That is, a fuel can sealed at one end with an end plug and opened at the other end is rotated around its pipe axis as the center on a rotationally diriving table. During rotation of the fuel can, nuclear fuel pellets are successively charged by means of a feed rod of a feeding device to the inside of the fuel can. The fuel can is rotated while being supported horizontally and the fuel pellets are charged from the open end thereof. Alternatively, the fuel can is rotated while being supported obliquely and the fuel pellets are charged gravitationally into the fuel can. In this way, the damages to the barrier of the fuel can can be reduce. Further, since the fuel pellets can be charged gravitationally by rotating the fuel can while being supported obliquely, the damages to the barrier can be reduced remarkably. (I.S.)

Fuel and nuclear fuel cycle

International Nuclear Information System (INIS)

Prunier, C.

1998-01-01

The nuclear fuel is studied in detail, the best choice and why in relation with the type of reactor, the properties of the fuel cans, the choice of fuel materials. An important part is granted to the fuel assembly of PWR type reactor and the performances of nuclear fuels are tackled. The different subjects for research and development are discussed and this article ends with the particular situation of mixed oxide fuels ( materials, behavior, efficiency). (N.C.)

MMIC front-ends for optical communication systems

DEFF Research Database (Denmark)

Petersen, Anders Kongstad

1993-01-01

Two different types of optical front-end MMIC amplifiers for a 2.5-Gb/s coherent heterodyne optical receiver are presented. A bandwidth of 6-12 GHz has been obtained for a tuned front-end and 3-13 GHz for a distributed front-end. An input noise current density of 5-15 pA/√Hz has been obtained for...

Device for separating, purifying and recovering nuclear fuel material, impurities and materials from impurity-containing nuclear fuel materials or nuclear fuel containing material

International Nuclear Information System (INIS)

Sato, Ryuichi; Kamei, Yoshinobu; Watanabe, Tsuneo; Tanaka, Shigeru.

1988-01-01

Purpose: To separate, purify and recover nuclear fuel materials, impurities and materials with no formation of liquid wastes. Constitution: Oxidizing atmosphere gases are introduced from both ends of a heating furnace. Vessels containing impurity-containing nuclear fuel substances or nuclear fuel substance-containing material are continuously disposed movably from one end to the other of the heating furnace. Then, impurity oxides or material oxides selectively evaporated from the impurity-containing nuclear fuel substances or nuclear fuel substance-containing materials are entrained in the oxidizing atmosphere gas and the gases are led out externally from a discharge port opened at the intermediate portion of the heating furnace, filters are disposed to the exit to solidify and capture the nuclear fuel substances and traps are disposed behind the filters to solidify and capture the oxides by spontaneous air cooling or water cooling. (Sekiya, K.)

The reprocessing-recycling of spent nuclear fuel. Actinides separation - Application to wastes management

International Nuclear Information System (INIS)

2008-01-01

After its use in the reactor, the spent fuel still contains lot of recoverable material for an energetic use (uranium, plutonium), but also fission products and minor actinides which represent the residues of nuclear reactions. The reprocessing-recycling of the spent fuel, as it is performed in France, implies the chemical separation of these materials. The development and the industrial implementation of this separation process represent a major contribution of the French science and technology. The reprocessing-recycling allows a good management of nuclear wastes and a significant saving of fissile materials. With the recent spectacular rise of uranium prices, this process will become indispensable with the development of the next generation of fast neutron reactors. This book takes stock of the present and future variants of the chemical process used for the reprocessing of spent fuels. It describes the researches in progress and presents the stakes and recent results obtained by the CEA. content: the separation of actinides, a key factor for a sustainable nuclear energy; the actinides, a discovery of the 20. century; the radionuclides in nuclear fuels; the aquo ions of actinides; some redox properties of actinides; some complexing properties of actinide cations; general considerations about treatment processes; some characteristics of nuclear fuels in relation with their reprocessing; technical goals and specific constraints of the PUREX process; front-end operations of the PUREX process; separation and purification operations of the PUREX process; elaboration of finite products in the framework of the PUREX process; management and treatment of liquid effluents; solid wastes of the PUREX process; towards a joint management of uranium and plutonium: the COEX TM process; technical options of treatment and recycling techniques; the fuels of generation IV reactors; front-end treatment processes of advanced fuels; hydrometallurgical processes for future fuel cycles

Back-end nuclear fuel cycle strategy: The approaches in Ukraine

International Nuclear Information System (INIS)

Afnasyev, A.; Medun, V.; Trehub, Yu.

2002-01-01

Ukraine has 14 nuclear units in operation and 4 units more under construction. Now in Ukraine a share of installed nuclear capacity in total installed capacity is essential and it is planned to increase it further. In this connection a spent nuclear fuel management in Ukraine for the current period and future is becoming important in a nuclear fuel cycle. A current situation in relation to the spent nuclear fuel management in Ukraine is described in the paper. It is reviewed: legislative basis for a spent nuclear fuel management strategy; an assessment for a spent fuel growth; the national possibilities for the spent fuel management; an organization chart for a spent nuclear fuel management, etc. Some factors that can determine a long-term spent fuel management strategy in Ukraine are in the conclusion. (author)

Fuel buyers guide: company data

International Nuclear Information System (INIS)

Anon.

1991-01-01

Four major listings relating to nuclear fuel services are provided. 1. A fuel buyer's guide listing companies under alphabetical order of country and giving addresses and an indication of the services offered. 2. A fuel buyers guide classifying companies in alphabetical order of the services offered. 3. A fuel and front end facility listing subdivided into companies involved in: uranium ore processing; uranium refining and conversion; enrichment; fuel fabrication; heavy water production; zirconium metal production; and zirconium tube production. 4. A fuel and front end facilities listing giving operators' addresses under alphabetical order of country. (UK)

Nuclear energy

International Nuclear Information System (INIS)

2007-01-01

This digest document was written by members of the union of associations of ex-members and retired people of the Areva group (UARGA). It gives a comprehensive overview of the nuclear industry world, starting from radioactivity and its applications, and going on with the fuel cycle (front-end, back-end, fuel reprocessing, transports), the nuclear reactors (PWR, BWR, Candu, HTR, generation 4 systems), the effluents from nuclear facilities, the nuclear wastes (processing, disposal), and the management and safety of nuclear activities. (J.S.)

Fast front-end electronics for COMPASS MWPCs

CERN Document Server

Colantoni, M L; Ferrero, A; Frolov, V; Grasso, A; Heinz, S; Maggiora, A; Maggiora, M G; Panzieri, D; Popov, A; Tchalyshev, V

2000-01-01

In the COMPASS experiment, under construction at CERN, about 23000 channels of MWPCs will be used. The very high rate of the muon and hadron beams, and the consequently high trigger rate, require front- end electronics with innovative conceptual design. A new MWPC front- end electronics that fulfills the main COMPASS requirement to have a fast DAQ with a minimum dead-time has been designed. The general concept of the front-end cards is described; the comparative tests of two front-end chips, and different fast gas mixtures, are also shown. The commissioning of the experiment will start in the summer 2000, and production running, using the muon beam, is foreseen for the year 2001. (8 refs).

The nuclear fuel elements' world market and the position of the Argentine Republic as producer

International Nuclear Information System (INIS)

Biondo, C.D.

1983-01-01

The development of the nuclear fuel elements' industry is analyzed, both in the present and projected world market, up to the year 2000, in the light of the situation affecting the nucleoelectric industry. By means of the offer/demand function, an analysis is made of the behaviour of the fuel elements' market throughout the fuel cycle structure. The regional unbalances between availability and demand of uranium resources are considered, as well as the factors having an unfavorable incidence on the fuel cycle's economic equation. The economic structure to be used for the calculation of the nucleoelectric generating cost is presented, in order to situate, within said nuclear economy, the component corresponding to the fuel cycle cost. Emphasis is placed on the 'front end' stages of the fuel cycle, but also considering those stages belonging to the 'back end'. Argentina's fuel elements market and its present and projected nucleoelectric park are analyzed, indicating their relative position in the world market. (R.J.S.) [es

RPC performance vs. front-end electronics

International Nuclear Information System (INIS)

Cardarelli, R.; Aielli, G.; Camarri, P.; Di Ciaccio, A.; Di Stante, L.; Liberti, B.; Pastori, E.; Santonico, R.; Zerbini, A.

2012-01-01

Moving the amplification from the gas to the front-end electronics was a milestone in the development of Resistive Plate Chambers. Here we discuss the historical evolution of RPCs and we show the results obtained with newly developed front-end electronics with threshold in the fC range.

Characteristics and Classification of Solid Radioactive Waste From the Front-End of the Uranium Fuel Cycle.

Science.gov (United States)

Liu, Xinhua; Wei, Fangxin; Xu, Chunyan; Liao, Yunxuan; Jiang, Jing

2015-09-01

The proper classification of radioactive waste is the basis upon which to define its disposal method. In view of differences between waste containing artificial radionuclides and waste with naturally occurring radionuclides, the scientific definition of the properties of waste arising from the front end of the uranium fuel cycle (UF Waste) is the key to dispose of such waste. This paper is intended to introduce briefly the policy and practice to dispose of such waste in China and some foreign countries, explore how to solve the dilemma facing such waste, analyze in detail the compositions and properties of such waste, and finally put forward a new concept of classifying such waste as waste with naturally occurring radionuclides.

Muon front end for the neutrino factory

CERN Document Server

Rogers, C T; Prior, G; Gilardoni, S; Neuffer, D; Snopok, P; Alekou, A; Pasternak, J

2013-01-01

In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

Analysis of Korean Nuclear Fuel Cycle System by Using DANESS Code

International Nuclear Information System (INIS)

Jeong, Chang Joon

2009-08-01

Korean fast reactor scenarios have been analyzed for various kinds of conversion ratio (CR) by the DANESS system dynamic analysis code. The once-through fuel cycle analysis was modeled based on the Korean 'National Energy Basic Plan' up to 2030 and a postulated nuclear demand growth rate until 2150. The fast reactor scenario analysis has been performed for three kinds of conversion ratios such as 0.3, 0.61 and 1.0. Through the calculations, the nuclear reactor deployment scenario, front-end cycle, back-end cycle, and long-term heat load have been investigated. From the once-through results, it is shown that the nuclear power demand would be ∼70 GWe and the total amount of the spent fuel accumulated by 2150 would be ∼168000 t. The fast reactor (FR) scenario analysis results show that the spent fuel inventory and out-pile transuranic element (TRU) can be reduced by increasing the fast reactor conversion ratio. Furthermore, the long-term heat load of spent fuel decreases with increasing the conversion ratio. However, it is known that the deployment of a fast reactor of low conversion ratio does not much reduce the spent fuel and out-pile TRU inventory due to the fast reactor deployment limitation which is related to the availability of TRU

Muon front end for the neutrino factory

Directory of Open Access Journals (Sweden)

C. T. Rogers

2013-04-01

Full Text Available In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

The economics of the back end of the nuclear fuel cycle

International Nuclear Information System (INIS)

Cameron, Ron; Urso, Maria Elena; Lokhov, Alexey

2014-01-01

Spent nuclear fuel and high-level waste from the fuel cycle of commercial nuclear power plants represent a small proportion of the radioactive waste produced globally by various industries (including medicine, agriculture and research), but they account for the greatest radioactivity content and longevity. While technologies are well developed and widely employed for the treatment and disposal of the much larger volumes of less radioactive low-level and short-lived intermediate-level waste, no final disposal facilities have yet been fully implemented for spent nuclear fuel (SNF) and high-level waste (HLW). A lack of experience in the construction and operation of deep geological repositories, combined with the extensive periods required for the implementation of back-end solutions, have thus contributed to growing uncertainties about the costs associated with managing SNF and HLW. The issue has become a central challenge for the nuclear industry and a matter of public concern and debate. Using official data supplied by national authorities, a descriptive overview [1] was developed of general principles and frameworks for the long-term management of SNF, current national policies and practices, as well as available and prospective technology options, including: - Direct disposal, where the fuel is used once and then regarded as waste for disposal. - Partial recycling, where the spent fuel is reprocessed to recover unused uranium and plutonium for recycling in light water reactors (LWRs). Once irradiated, the recycled fuel bundles can be either stored (with the perspective of their reprocessing and recycling in future fast reactors - FRs) or disposed of after encapsulation. - Advanced systems and fuel cycle concepts for the longer-term future, studied theoretically or on a pilot scale, with the dual objective of reducing the mass and radioactivity of waste destined to final disposal and optimising the use of natural resources. In addition, a cost analysis of these

Development of remote welding technology for nuclear fuel end capping (A study on the weldability of Zircaloy-4)

Energy Technology Data Exchange (ETDEWEB)

Kho, Jin Hyun; Sung, Ho Hyun; Hyun, Yong Kyu; Suh, Hee Kang [Korea University of Technology and Education, Cheonan (Korea)

1998-03-01

The integrity of nuclear fuel end cap welds is essential to the nuclear fuel performance and safety as well as the usability of power plant. The first aim of this project is to obtain experimental data on the nuclear fuel cladding materials of Zircaloy-4 with welding processes such as plasma arc, gas tungsten arc and laser beam welding. the data obtained in this study will be applicable to the nuclear fuel design, fabrication and nuclear fuel quality control. In addition, the welding processes applicable to the Zircaloy-4 welding were compared and contrasted. The weldability of Zircaloy-4 was evaluated from the metallurgical and mechanical standpoints. 88 refs., 57 figs., 16 tabs. (Author)

Characterization of the head end cells at the West Valley Nuclear Fuel Reprocessing Plant

International Nuclear Information System (INIS)

Vance, R.F.

1986-11-01

The head-end cells at the West Valley Nuclear Fuel Reprocessing Plant are characterized in this report. These cells consist of the Process Mechanical Cell (PMC) where irradiated nuclear fuel was trimmed of excess hardware and sheared into short segments; and the General Purpose Cell (GPC) where the segments were collected and stored prior to dissolution, and leached hulls were packaged for disposal. Between 1966 and 1972, while Nuclear Fuels Services operated the plant, these cells became highly contaminated with radioactive materials. The purpose of this characterization work was to develop technical information as a basis of decontamination and decommissioning planning and engineering. It was accomplished by performing remote in-cell visual examinations, radiation surveys, and sampling. Supplementary information was obtained from available written records, out-of-cell inspections, and interviews with plant personnel

International co-operation in the supply of nuclear fuel and fuel cycle services

International Nuclear Information System (INIS)

Sievering, N.F. Jr.

1977-01-01

Recent changes in the United States' nuclear policy, in recognition of the increased proliferation risk, have raised questions of US intentions in international nuclear fuel and fuel-cycle service co-operation. This paper details those intentions in relation to the key elements of the new policy. In the past, the USA has been a world leader in peaceful nuclear co-operation with other nations and, mindful of the relationships between civilian nuclear technology and nuclear weapon proliferation, remains strongly committed to the Non-Proliferation Treaty, IAEA safeguards and other elements concerned with international nuclear affairs. Now, in implementing President Carter's nuclear initiatives, the USA will continue its leading role in nuclear fuel and fuel-cycle co-operation in two ways, (1) by increasing its enrichment capacity for providing international LWR fuel supplies and (2) by taking the lead in solving the problems of near and long-term spent fuel storage and disposal. Beyond these specific steps, the USA feels that the international community's past efforts in controlling the proliferation risks of nuclear power are necessary but inadequate for the future. Accordingly, the USA urges other similarly concerned nations to pause with present developments and to join in a programme of international co-operation and participation in a re-assessment of future plans which would include: (1) Mutual assessments of fuel cycles alternative to the current uranium/plutonium cycle for LWRs and breeders, seeking to lessen proliferation risks; (2) co-operative mechanisms for ensuring the ''front-end'' fuel supply including uranium resource exploration, adequate enrichment capacity, and institutional arrangements; (3) means of dealing with short-, medium- and long-term spent fuel storage needs by means of technical co-operation and assistance and possibly establishment of international storage or repository facilities; and (4) for reprocessing plants, and related fuel

The Union view of back end fuel cycle provisions for nuclear power plants

International Nuclear Information System (INIS)

Anon.

1981-01-01

After a long political and technical discussion, the German trade unions united in the German Federation of Labor (DGB) arrived at the finding that back end fuel cycle provisions for nuclear power plants in the Federal Republic of Germany, in addition to the present concept of the Government providing for a reprocessing plant, should also include studies of the alternative possibility to store spent fuel elements over long periods of time, perhaps with a possibility to recover them later. That decision is also based on a report by the Nuclear Technology Working Group of the Metal Workers Union (IG Metall) and the Public Workers Union (OeTV). (orig.) [de

Nuclear fuel element

International Nuclear Information System (INIS)

Hirama, H.

1978-01-01

A nuclear fuel element comprises an elongated tube having upper and lower end plugs fixed to both ends thereof and nuclear fuel pellets contained within the tube. The fuel pellets are held against the lower end plug by a spring which is supported by a setting structure. The setting structure is maintained at a proper position at the middle of the tube by a wedge effect caused by spring force exerted by the spring against a set of balls coacting with a tapered member of the setting structure thereby wedging the balls against the inner wall of the tube, and the setting structure is moved free by pushing with a push bar against the spring force so as to release the wedge effect

Development and Demonstration of a Magnesium-Intensive Vehicle Front-End Substructure

Energy Technology Data Exchange (ETDEWEB)

Logan, Stephen D. [United States Automotive Materials Partnership LLC, Southfield, MI (United States); Forsmark, Joy H. [United States Automotive Materials Partnership LLC, Southfield, MI (United States); Osborne, Richard [United States Automotive Materials Partnership LLC, Southfield, MI (United States)

2016-07-01

This project is the final phase (designated Phase III) of an extensive, nine-year effort with the objectives of developing a knowledge base and enabling technologies for the design, fabrication and performance evaluation of magnesium-intensive automotive front-end substructures intended to partially or completely replace all-steel comparators, providing a weight savings approaching 50% of the baseline. Benefits of extensive vehicle weight reduction in terms of fuel economy increase, extended vehicle range, vehicle performance and commensurate reductions in greenhouse gas emissions are well known. An exemplary vehicle substructure considered by the project is illustrated in Figure 1, along with the exterior vehicle appearance. This unibody front-end “substructure” is one physical objective of the ultimate design and engineering aspects established at the outset of the larger collective effort.

Next generation of optical front-ends for numerical services - 15387

International Nuclear Information System (INIS)

Fullenbaum, M.; Durieux, A.; Dubroca, G.; Fuss, P.

2015-01-01

Visual Inspection and surveillance technology means in environments exhibiting high levels of gamma and neutron radiation are nowadays fulfilled through the use of analog tubes. The images are thus acquired with analog devices whose vast majority relies on 1 and 2/3 inch imaging formats and deliver native analog images. There is a growing demand for real time image processing and distribution through Ethernet services for quicker and seamless process integration throughout many sectors. This will call for the inception of solid state sensor (CCD, CMOS) to generate numerical native images as the first step and building block towards end to end numerical processing (ICT), assuming these sensors can be hardened or protected in the field of the nuclear industry. On the one hand, these sensor sizes will be significantly reduced (by a factor of 2-3) versus those of the tubes, and on the other hand, one will also be presented with the opportunity of increased spatial resolution, stemming from the high pixel count of the solid state technology, for implementation of new or better services or of enhanced pieces of information for decision making purposes. In order to reap the benefits of such sensors, new optical front-ends will have to be designed. Over and beyond the mere aspects of matching the reduced sensor size to the size of the scenes at stake, optical performances of these front-end will also bear an impact on the whole optical chain applications. As an example, detection and tracking needs will be different from a performance standpoint and the overall performances will have to be balanced out in between the optical front-end, the image format, the image processing software capability, processing speed,...just to name a few. In this paper we will review and explain the missing gaps in order to switch to a full numerical optical chain by focusing on the optical front-end and the associated cost trade-offs. Finally, we will conclude by clearly stating the best

Nuclear Fuel Cycle Information System. A directory of nuclear fuel cycle facilities. 2009 ed

International Nuclear Information System (INIS)

2009-04-01

The Nuclear Fuel Cycle Information System (NFCIS) is an international directory of civilian nuclear fuel cycle facilities, published online as part of the Integrated Nuclear Fuel Cycle Information System (iNFCIS: http://www-nfcis.iaea.org/). This is the fourth hardcopy publication in almost 30 years and it represents a snapshot of the NFCIS database as of the end of 2008. Together with the attached CD-ROM, it provides information on 650 civilian nuclear fuel cycle facilities in 53 countries, thus helping to improve the transparency of global nuclear fuel cycle activities

Principles of provision concerning the back-end of the fuel cycle of nuclear power plants find application

International Nuclear Information System (INIS)

1977-01-01

The Ministry of the Interior has asked the Laender on the 14th June 1977, to apply forthwith the 'principles of provision concerning the back-end of the fuel cycle of nuclear power plants' as a minimum pre-condition for waste management in licensing procedures for nuclear power stations. The 'principles' were part of a report, elaborated by a Bund/Laender working group at a undersecretary-of-state level on questions concerning the back-end of the fuel cycle of nuclear power plants. The report was favourably acknowledged during a meeting of the Federal Chancellor and the Minister-Presidents of the Laender on May 6th, 1977. The principles are presented. (orig./HP) [de

Nuclear energy; Le nucleaire

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

This digest document was written by members of the union of associations of ex-members and retired people of the Areva group (UARGA). It gives a comprehensive overview of the nuclear industry world, starting from radioactivity and its applications, and going on with the fuel cycle (front-end, back-end, fuel reprocessing, transports), the nuclear reactors (PWR, BWR, Candu, HTR, generation 4 systems), the effluents from nuclear facilities, the nuclear wastes (processing, disposal), and the management and safety of nuclear activities. (J.S.)

Recycle and reuse of materials and components from waste streams of nuclear fuel cycle facilities

International Nuclear Information System (INIS)

2000-01-01

All nuclear fuel cycle processes utilize a wide range of equipment and materials to produce the final products they are designed for. However, as at any other industrial facility, during operation of the nuclear fuel cycle facilities, apart from the main products some byproducts, spent materials and waste are generated. A lot of these materials, byproducts or some components of waste have a potential value and may be recycled within the original process or reused outside either directly or after appropriate treatment. The issue of recycle and reuse of valuable material is important for all industries including the nuclear fuel cycle. The level of different materials involvement and opportunities for their recycle and reuse in nuclear industry are different at different stages of nuclear fuel cycle activity, generally increasing from the front end to the back end processes and decommissioning. Minimization of waste arisings and the practice of recycle and reuse can improve process economics and can minimize the potential environmental impact. Recognizing the importance of this subject, the International Atomic Energy Agency initiated the preparation of this report aiming to review and summarize the information on the existing recycling and reuse practice for both radioactive and non-radioactive components of waste streams at nuclear fuel cycle facilities. This report analyses the existing options, approaches and developments in recycle and reuse in nuclear industry

Nuclear fuel pellet loading apparatus

International Nuclear Information System (INIS)

Gerkey, K.S.

1979-01-01

An automatic apparatus for loading a predetermined amount of nuclear fuel pellets into a nuclear fuel element to be used in a nuclear reactor is described. The apparatus consists of a vibratory bed capable of supporting corrugated trays containing rows of nuclear fuel pellets and arranged in alignment with the open ends of several nuclear fuel elements. A sweep mechanism is arranged above the trays and serves to sweep the rows of fuel pellets onto the vibratory bed and into the fuel element. A length detecting system, in conjunction with a pellet stopping mechanism, is also provided to assure that a predetermined amount of nuclear fuel pellets are loaded into each fuel element

Novel Front-end Electronics for Time Projection Chamber Detectors

CERN Document Server

García García, Eduardo José

This work has been carried out in the European Organization for Nuclear Research (CERN) and it was supported by the European Union as part of the research and development towards the European detector the (EUDET) project, specifically for the International Linear Collider (ILC). In particle physics there are several different categories of particle detectors. The presented design is focused on a particular kind of tracking detector called Time Projection Chamber (TPC). The TPC provides a three dimensional image of electrically charged particles crossing a gaseous volume. The thesis includes a study of the requirements for future TPC detectors summarizing the parameters that the front-end readout electronics must fulfill. In addition, these requirements are compared with respect to the readouts used in existing TPC detectors. It is concluded that none of the existing front-end readout designs fulfill the stringent requirements. The main requirements for future TPC detectors are high integration, an increased n...

The upgraded CDF front end electronics for calorimetry

Energy Technology Data Exchange (ETDEWEB)

Drake, G.; Frei, D.; Hahn, S.R.; Nelson, C.A.; Segler, S.L.; Stuermer, W.

1991-11-01

The front end electronics used in the calorimetry of the CDF detector has been upgraded to meet system requirements for higher expected luminosity. A fast digitizer utilizing a 2 {mu}Sec, 16 bit ADC has been designed and built. Improvements to the front end trigger circuitry have been implemented, including the production of 900 new front end modules. Operational experience with the previous system is presented, with discussion of the problems and performance goals.

The upgraded CDF front end electronics for calorimetry

International Nuclear Information System (INIS)

Drake, G.; Frei, D.; Hahn, S.R.; Nelson, C.A.; Segler, S.L.; Stuermer, W.

1991-11-01

The front end electronics used in the calorimetry of the CDF detector has been upgraded to meet system requirements for higher expected luminosity. A fast digitizer utilizing a 2 μSec, 16 bit ADC has been designed and built. Improvements to the front end trigger circuitry have been implemented, including the production of 900 new front end modules. Operational experience with the previous system is presented, with discussion of the problems and performance goals

Adaptive RF front-ends for hand-held applications

CERN Document Server

van Bezooijen, Andre; van Roermund, Arthur

2010-01-01

The RF front-end - antenna combination is a vital part of a mobile phone because its performance is very relevant to the link quality between hand-set and cellular network base-stations. The RF front-end performance suffers from changes in operating environment, like hand-effects, that are often unpredictable. ""Adaptive RF Front-Ends for Hand-Held Applications"" presents an analysis on the impact of fluctuating environmental parameters. In order to overcome undesired behavior two different adaptive control methods are treated that make RF frond-ends more resilient: adaptive impedance control,

The Back End of the Fuel Cycle Moves Front and Center

International Nuclear Information System (INIS)

Isaacs, T; Choi, J

2005-01-01

For many years, the commercial nuclear business has remained relatively stable in many ways. That is unlikely to be the case in the coming years. While some countries have called for the phase out of nuclear power and others have ordered a small number of new plants, the overall profile of the nuclear power business has changed little. The number of countries with nuclear power plants is not much different than 10 years ago and the total number of operating plants has increased only slightly. Commercial enrichment and reprocessing services have remained the province of a few countries and consortia. Repository programs have moved forward slowly in some cases, backward in others, with a very small number making substantial progress. We are now witnessing the beginnings of serious change, with significant consequences for the future nuclear regime. Business as usual will not be the business of the future. The way the nuclear and policy community respond will have much to do with energy adequacy, national security, international stability, and environmental consequences including waste management and disposal. A number of events and trends are becoming increasingly apparent and are cause for both opportunity and caution: (1) New nuclear power plant orders are likely to grow and spread, particularly in the developing world, e.g. China and India. (2) The growing recognition that the developing world will be a major competitor for limited energy resources is raising awareness in the developed world regarding concerns for future energy security. (3) Clearer evidence of the effects of greenhouse gas emissions on global warming, largely from the burning of fossil fuels, is creating more attention on the environmental benefits of nuclear power. (4) The last decade has shown unequivocal evidence of countries lying, cheating on their NPT obligation, and covertly carrying out nuclear weapons-related activities. Some countries have suggested their presumed need for a domestic

Back end of an enduring fuel cycle

International Nuclear Information System (INIS)

Pillay, K.K.S.

1998-03-01

An enduring nuclear fuel cycle is an essential part of sustainable consumption, the process whereby world's riches are consumed in a responsible manner so that future generations can continue to enjoy at least some of them. In many countries, the goal of sustainable development has focused attention on the benefits of nuclear technologies. However, sustenance of the nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including energy, spent fuels, and all of its side streams. The nuclear fuel cycle for energy production has suffered many traumas since the mid seventies. The common basis of technologies producing nuclear explosives and consumable nuclear energy has been a preoccupation for some, predicament for others, and a perception problem for many. It is essential to reestablish a reliable back end of the nuclear fuel cycle that can sustain the resource requirements of an enduring full cycle. This paper identifies some pragmatic steps necessary to reverse the trend and to maintain a necessary fuel cycle option for the future

Back end of the fuel cycle

International Nuclear Information System (INIS)

Wolfe, B.; Lambert, R.W.

1975-01-01

At present, that portion of the nuclear fuel cycle involving reprocessing, waste management, and mixed-oxide fuel fabrication is in an unsettled state. Government regulatory requirements with respect to all aspects of the back end of the fuel cycle are still being formulated, and there is little positive experience on the operation of commercial reprocessing or mixed-oxide fabrication plants. In view of this unsettled situation, it will be difficult to meet the reprocessing and mixed-oxide fabrication needs of the next decade in the pattern previously anticipated. The costs in the back end of the fuel cycle are much higher than had been anticipated several years ago, a situation similar to that of almost all large endeavors in this country. On the other hand, the added costs are small relative to total power costs and do not affect the economic advantage of nuclear power as compared to other power sources. A rough economic analysis indicates that the question for the back end of the fuel cycle has changed from one of optimizing profitability to one of determining the most economic disposition of spent fuel. Long-term spent fuel storage is a practical and economically acceptable way to provide time for determining a sound course of action for the back end of the fuel cycle. Indeed, if one could count on a breeder economy before the end of the century, one possible course of action is to store light-water fuel until the plutonium can be used in breeders. However, for philosophical as well as practical reasons, it is important that the uncertainties in the course of action should be resolved as quickly as possible. Long-term storage should not be an excuse to delay resolution of the basic questions. (U.S.)

Apparatus and process for separating end of nuclear fuel assembly

International Nuclear Information System (INIS)

Beneck, J.A.; Quayre, C.; Moreau, J.R.M.; Vermeille, D.E.A.

1989-01-01

The apparatus for cutting the guide tubes of a nuclear fuel assembly below the bottom nozzle has a framework with removable fixation and centering means on the bottom nozzle. Cutting devices in the form of hollow pins are inserted simultaneously into all the guide tubes. Each pin contains a shaft that is moved axially inside it by the expansion system to deploy or retract a cutting edge near the lower end of the pin. A single motor using a gear wheel system, rotates all the cutting pins simultaneously [fr

Investigation of economics of back-end nuclear fuel cycle options in the Republic of Korea based on Once-through

Energy Technology Data Exchange (ETDEWEB)

Cho, Seok-Ki; Yim, Man-Sung [Korea Advance Institute of Science and Technology, Daejeon (Korea, Republic of)

2015-05-15

The purpose of this study is to examine these questions and perform economic evaluations of various cases of Once-through back-end fuel cycles in the ROK. Therefore, the study is to support decision making in terms of how the long term spent nuclear fuel (SNF) management strategy should be developed. A spreadsheet model was developed to plan reactor construction, the interim storage and the HLW repository construction within engineered constraints, based on the estimation of the spent fuel flow and the energy supply of the nuclear power program. The model computes the back-end levelized costs for various fuel cycle choices. The scenarios assumed in the model include (1) 0 year/10year/20year of licensed operation period extension; (2) the phase-out of NPP program and the continuous use including the reunification of Korean peninsula; (3) reactor decommissioning and construction lead times - 10 years and 5 years respectively in this study; (4) geological constraints of siting for a new reactor - 38 for without the reunification and 70 for with the reunification; (5) the first initiation of reactor decommissioning and operation of HLW repository - assumed to be 2020 and 2050; and (6) capacity factor of reactor operation and the on-site wet storage pool capacity - 0.85 and 0.498 MTHM per MWe which is equivalent with APR1400. The capacity factor for PHWR reactors was assumed at 0.85 and the plan for PHWR was fixed as phase-out. The spreadsheet model conducts computation for annual expenditures of the back-end fuel cycle and calculates the levelized costs. Licensed operation period extension enhances not only economic efficiency, stable energy supply, but also reduces burden of siting for a new reactor and waste disposal. And regardless the reunification, continuous use of nuclear energy lowers the back-end fuel cycle cost. With projection that a large portion of social cost is included in the current back-end fuel cycle cost, nuclear energy likely has more competency in

Managing Controversies in the Fuzzy Front End

DEFF Research Database (Denmark)

Christiansen, John K.; Gasparin, Marta

2016-01-01

This research investigates the controversies that emerge in the fuzzy front end (FFE) and how they are closed so the innovation process can move on. The fuzzy front has been characterized in the literature as a very critical phase, but controversies in the FFE have not been studied before....... The analysis investigates the microprocesses around the controversies that emerge during the fuzzy front end of four products. Five different types of controversies are identified: profit, production, design, brand and customers/market. Each controversy represents a threat, but also an opportunity to search...

Nuclear fuel element

International Nuclear Information System (INIS)

Yamamoto, Seigoro.

1994-01-01

Ultrafine particles of a thermal neutron absorber showing ultraplasticity is dispersed in oxide ceramic fuels by more than 1% to 10% or lower. The ultrafine particles of the thermal neutron absorber showing ultrafine plasticity is selected from any one of ZrGd, HfEu, HfY, HfGd, ZrEu, and ZrY. The thermal neutron absorber is converted into ultrafine particles and solid-solubilized in a nuclear fuel pellet, so that the dispersion thereof into nuclear fuels is made uniform and an absorbing performance of the thermal neutrons is also made uniform. Moreover, the characteristics thereof, for example, physical properties such as expansion coefficient and thermal conductivity of the nuclear fuels are also improved. The neutron absorber, such as ZrGd or the like, can provide plasticity of nuclear fuels, if it is mixed into the nuclear fuels for showing the plasticity. The nuclear fuel pellets are deformed like an hour glass as burning, but, since the end portion thereof is deformed plastically within a range of a repulsive force of the cladding tube, there is no worry of damaging a portion of the cladding tube. (N.H.)

Nuclear fuel elements

International Nuclear Information System (INIS)

Ainsworth, K.F.

1979-01-01

A nuclear fuel element is described having a cluster of nuclear fuel pins supported in parallel, spaced apart relationship by transverse cellular braces within coaxial, inner and outer sleeves, the inner sleeve being in at least two separate axial lengths, each of the transverse braces having a peripheral portion which is clamped peripherally between the ends of the axial lengths of the inner sleeve. (author)

2010 ANNUAL MEETING ON NUCLEAR TECHNOLOGY. Pt. 3. Section reports

International Nuclear Information System (INIS)

Arnold, Uwe; Baumann, Erik; Fischer, Ulrich; Bohnstedt, Angelika; Gehring, Michael; Roedig, Manfred; Willschuetz, Hans-Georg; Goers, Stefan; Schoenfelder, Christian

2010-01-01

Summary report on these 6 - out of 12 - Sessions of the Annual Conference on Nuclear Technology held in Berlin on May 3 to 6, 2010: - Decommissioning of Nuclear Installations (Session 7), - Fusion Technology (Session 8), - Energy Industry and Economics (Session 10), - Radiation Protection (Session 11), - New Build and Innovations (Session 12), and - Education, Expert Knowledge, Know-how-Transfer (Session 13). The other Sessions: - Reactor Physics and Methods of Calculation (Session 1), - Thermodynamics and Fluid Dynamics (Session 2), - Safety of Nuclear Installations - Methods, Analysis, Results (Session 3), - Front End and Back End of the Fuel Cycle, Radioactive Waste, Storage (Session 4), - Front End of the Fuel Cycle, Fuel Elements and Core Components (Session 5), - Operation of Nuclear Installations (Session 6) have been covered in atw issues 10 and 11 (2010). (orig.)

Minimization of waste from uranium purification, enrichment and fuel fabrication

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-10-01

As any industry, nuclear industry generates a diverse range of waste which has to be managed in a safe manner to be acceptable to the public and the environment. The cost of waste management, the risks to the public and employees, and the detriment to the environment are dependent on the quantity and radioactive content of the waste generated. Waste minimization is a necessary activity needed to reduce the impact from nuclear fuel cycle operations and it is included in the national policy of some countries. In recognition of the importance of the subject, the IAEA has decided to review the current status of the work aimed at waste minimization in the nuclear fuel cycle. The waste minimization issues related to the back end of the nuclear fuel cycle are covered in Technical Reports Series No. 377 'Minimization of Radioactive Waste from Nuclear Power Plants and the Back End of the Nuclear Fuel Cycle' published in 1995. The present report deals with the front end of the nuclear fuel cycle, including existing options, approaches, developments and some specific considerations to be taken into account in decision making on waste minimization. It has been recognized that, in comparison with the back end of the nuclear fuel cycle, much less information is available, and this report should be considered as a first attempt to analyse waste minimization practices and opportunities in uranium purification, conversion, enrichment and fuel fabrication. Although mining and milling is an important part of the front end of the nuclear fuel cycle, these activities are excluded from consideration since relevant activities are covered in other IAEA publications.

Minimization of waste from uranium purification, enrichment and fuel fabrication

International Nuclear Information System (INIS)

1999-10-01

As any industry, nuclear industry generates a diverse range of waste which has to be managed in a safe manner to be acceptable to the public and the environment. The cost of waste management, the risks to the public and employees, and the detriment to the environment are dependent on the quantity and radioactive content of the waste generated. Waste minimization is a necessary activity needed to reduce the impact from nuclear fuel cycle operations and it is included in the national policy of some countries. In recognition of the importance of the subject, the IAEA has decided to review the current status of the work aimed at waste minimization in the nuclear fuel cycle. The waste minimization issues related to the back end of the nuclear fuel cycle are covered in Technical Reports Series No. 377 'Minimization of Radioactive Waste from Nuclear Power Plants and the Back End of the Nuclear Fuel Cycle' published in 1995. The present report deals with the front end of the nuclear fuel cycle, including existing options, approaches, developments and some specific considerations to be taken into account in decision making on waste minimization. It has been recognized that, in comparison with the back end of the nuclear fuel cycle, much less information is available, and this report should be considered as a first attempt to analyse waste minimization practices and opportunities in uranium purification, conversion, enrichment and fuel fabrication. Although mining and milling is an important part of the front end of the nuclear fuel cycle, these activities are excluded from consideration since relevant activities are covered in other IAEA publications

The front-end amplifier for the silicon microstrip sensors of the PANDA MVD

Energy Technology Data Exchange (ETDEWEB)

Di Pietro, Valentino; Brinkmann, Kai-Thomas; Riccardi, Alberto [II. Physikalisches Institut, JLU Giessen (Germany); Rivetti, Angelo; Rolo, Manuel [INFN Sezione di Torino (Italy)

2015-07-01

The most common readout systems designed for the nuclear physics detectors are based on amplitude measurements. The information that needs to be preserved is the charge delivered by a particle hitting the sensor. The electronic chain employed in these cases is made from two main building blocks: front-end amplifier and ADC. One of the issues associated with the implementation of such an architecture in scaled CMOS technologies is the dynamic range, because the charge information is extrapolated through the sampling of the peak of the front-end output signal. It is therefore interesting to explore the possibility of using time-based architectures offering better performances from that point of view. In fact, in these topologies the linearity between the charge and the signal duration can be maintained even if some building blocks in the chain saturate. The main drawback is the loss in resolution since a duration measurement involves the difference between two time measurements. This work will present the design of a front-end optimized for fast Time-over-Threshold applications. The circuit has been developed for the microstrip detectors of the PANDA experiment. The key features of the front-end amplifier are illustrated and both schematic level, and post-layout simulations are discussed.

Prospect and problems of self-supporting nuclear fuel cycle operation in Korea beyond the year 2000

International Nuclear Information System (INIS)

Kim, Chang Hyo

1988-01-01

Korea ranks tenth in the free world in the installed capacity of nuclear power plants. Since she lacks in indigenous uranium resources and built-in domestic fuel cycle technology, however, she had to rely heavily upon overseas uranium markets and fuel cycle services. Despite the fact that localization of fuel fabrication technology is nearly achieved, such issues as the timely and stable procurement of front-end fuel cycle services including uranium ore, interim storage and ultimate fuel cycle services including uranium ore, interim storage and ultimate disposal of ever-accumulating spent fuels, disposal of radioactive waste, and decommissioning of the retiring nuclear power plants has yet fuel cycle technology beyond the year 2000. The purpose of this report is to identify these issues of fuel cycle operation and to suggest mobilizing nation's research potential for establishing self-reliant fuel cycle technology beyond the year 2000

Axially alignable nuclear fuel pellets

International Nuclear Information System (INIS)

Johansson, E.B.; Klahn, D.H.; Marlowe, M.O.

1978-01-01

An axially alignable nuclear fuel pellet of the type stacked in end-to-end relationship within a tubular cladding is described. Fuel cladding failures can occur at pellet interface locations due to mechanical interaction between misaligned fuel pellets and the cladding. Mechanical interaction between the cladding and the fuel pellets loads the cladding and causes increased cladding stresses. Nuclear fuel pellets are provided with an end structure that increases plastic deformation of the pellets at the interface between pellets so that lower alignment forces are required to straighten axially misaligned pellets. Plastic deformation of the pellet ends results in less interactions beween the cladding and the fuel pellets and significantly lowers cladding stresses. The geometry of pellets constructed according to the invention also reduces alignment forces required to straighten fuel pellets that are tilted within the cladding. Plastic deformation of the pellets at the pellet interfaces is increased by providing pellets with at least one end face having a centrally-disposed raised area of convex shape so that the mean temperature and shear stress of the contact area is higher than that of prior art pellets

Legal, institutional, and political issues in transportation of nuclear materials at the back end of the LWR nuclear fuel cycle

International Nuclear Information System (INIS)

Lippek, H.E.; Schuller, C.R.

1979-03-01

A study was conducted to identify major legal and institutional problems and issues in the transportation of spent fuel and associated processing wastes at the back end of the LWR nuclear fuel cycle. (Most of the discussion centers on the transportation of spent fuel, since this activity will involve virtually all of the legal and institutional problems likely to be encountered in moving waste materials, as well.) Actions or approaches that might be pursued to resolve the problems identified in the analysis are suggested. Two scenarios for the industrial-scale transportation of spent fuel and radioactive wastes, taken together, high-light most of the major problems and issues of a legal and institutional nature that are likely to arise: (1) utilizing the Allied General Nuclear Services (AGNS) facility at Barnwell, SC, as a temporary storage facility for spent fuel; and (2) utilizing AGNS for full-scale commercial reprocessing of spent LWR fuel

Legal, institutional, and political issues in transportation of nuclear materials at the back end of the LWR nuclear fuel cycle

Energy Technology Data Exchange (ETDEWEB)

Lippek, H.E.; Schuller, C.R.

1979-03-01

A study was conducted to identify major legal and institutional problems and issues in the transportation of spent fuel and associated processing wastes at the back end of the LWR nuclear fuel cycle. (Most of the discussion centers on the transportation of spent fuel, since this activity will involve virtually all of the legal and institutional problems likely to be encountered in moving waste materials, as well.) Actions or approaches that might be pursued to resolve the problems identified in the analysis are suggested. Two scenarios for the industrial-scale transportation of spent fuel and radioactive wastes, taken together, high-light most of the major problems and issues of a legal and institutional nature that are likely to arise: (1) utilizing the Allied General Nuclear Services (AGNS) facility at Barnwell, SC, as a temporary storage facility for spent fuel; and (2) utilizing AGNS for full-scale commercial reprocessing of spent LWR fuel.

Concepts for a Muon Accelerator Front-End

Energy Technology Data Exchange (ETDEWEB)

Stratakis, Diktys [Fermilab; Berg, Scott [Brookhaven; Neuffer, David [Fermilab

2017-03-16

We present a muon capture front-end scheme for muon based applications. In this Front-End design, a proton bunch strikes a target and creates secondary pions that drift into a capture channel, decaying into muons. A series of rf cavities forms the resulting muon beams into a series of bunches of differerent energies, aligns the bunches to equal central energies, and initiates ionization cooling. We also discuss the design of a chicane system for the removal of unwanted secondary particles from the muon capture region and thus reduce activation of the machine. With the aid of numerical simulations we evaluate the performance of this Front-End scheme as well as study its sensitivity against key parameters such as the type of target, the number of rf cavities and the gas pressure of the channel.

World nuclear fuel cycle requirements 1991

Energy Technology Data Exchange (ETDEWEB)

1991-10-10

The nuclear fuel cycle consists of mining and milling uranium ore, processing the uranium into a form suitable for generating electricity, burning'' the fuel in nuclear reactors, and managing the resulting spent nuclear fuel. This report presents projections of domestic and foreign requirements for natural uranium and enrichment services as well as projections of discharges of spent nuclear fuel. These fuel cycle requirements are based on the forecasts of future commercial nuclear power capacity and generation published in a recent Energy Information Administration (EIA) report. Also included in this report are projections of the amount of spent fuel discharged at the end of each fuel cycle for each nuclear generating unit in the United States. The International Nuclear Model is used for calculating the projected nuclear fuel cycle requirements. 14 figs., 38 tabs.

World nuclear fuel cycle requirements 1991

International Nuclear Information System (INIS)

1991-01-01

The nuclear fuel cycle consists of mining and milling uranium ore, processing the uranium into a form suitable for generating electricity, ''burning'' the fuel in nuclear reactors, and managing the resulting spent nuclear fuel. This report presents projections of domestic and foreign requirements for natural uranium and enrichment services as well as projections of discharges of spent nuclear fuel. These fuel cycle requirements are based on the forecasts of future commercial nuclear power capacity and generation published in a recent Energy Information Administration (EIA) report. Also included in this report are projections of the amount of spent fuel discharged at the end of each fuel cycle for each nuclear generating unit in the United States. The International Nuclear Model is used for calculating the projected nuclear fuel cycle requirements. 14 figs., 38 tabs

The utmost ends of the nuclear fuel cycle. How Finns perceive the risks of uranium mining and nuclear waste management

Energy Technology Data Exchange (ETDEWEB)

Litmanen, Tapio (Univ. of Jyvaeskylae, Dept. of Social Sciences and Philosophy, Jyvaeskylae (Finland)), e-mail: Tapio.Litmanen@jyu.fi

2010-09-15

The aim of the paper is to analyze how Finns perceive the risks of uranium mining and nuclear waste management. In social science quite much research has been done on the issue of how people perceive the risks of nuclear waste and nuclear waste management, but not much has been done in analyzing the similarities and differences of risk perception (and ethical considerations) of the utmost ends of nuclear fuel cycle. There have been some changes in Finnish nuclear policy during ongoing decade, which make this type of study interesting: decision on the fifth nuclear power plant was done in 2002, the site for spent nuclear fuel has been chosen in 2001 and in 2010 the Parliament will decide which of three competitors will get the permission to construct the sixth nuclear power plant. This national nuclear renaissance was accompanied with the uranium boom, which started in 2005. New international interest in nuclear power had raised the price of uranium. International mining companies started uranium explorations because Finnish bedrock is the oldest in Europe, and it is similar with and also of the same age as is that of the great uranium producers, Canada and Australia. The analysis of risk perceptions between uranium questions and spent nuclear fuel is based on the national survey data (N=1180) gathered in 2007

The utmost ends of the nuclear fuel cycle. How Finns perceive the risks of uranium mining and nuclear waste management

International Nuclear Information System (INIS)

Litmanen, Tapio

2010-09-01

The aim of the paper is to analyze how Finns perceive the risks of uranium mining and nuclear waste management. In social science quite much research has been done on the issue of how people perceive the risks of nuclear waste and nuclear waste management, but not much has been done in analyzing the similarities and differences of risk perception (and ethical considerations) of the utmost ends of nuclear fuel cycle. There have been some changes in Finnish nuclear policy during ongoing decade, which make this type of study interesting: decision on the fifth nuclear power plant was done in 2002, the site for spent nuclear fuel has been chosen in 2001 and in 2010 the Parliament will decide which of three competitors will get the permission to construct the sixth nuclear power plant. This national nuclear renaissance was accompanied with the uranium boom, which started in 2005. New international interest in nuclear power had raised the price of uranium. International mining companies started uranium explorations because Finnish bedrock is the oldest in Europe, and it is similar with and also of the same age as is that of the great uranium producers, Canada and Australia. The analysis of risk perceptions between uranium questions and spent nuclear fuel is based on the national survey data (N=1180) gathered in 2007

2010 ANNUAL MEETING ON NUCLEAR TECHNOLOGY. Pt. 4. Section reports

International Nuclear Information System (INIS)

Berlepsch, Thilo v.; Hering, Wolfgang

2011-01-01

Summary report on 2 Sessions of Section: - New Build and Innovations (Section 12) of the ANNUAL MEETING On NUCLEAR TECHNOLOGY held in Berlin on May 4 to 6, 2010. The other Sections 'Reactor Physics and Methods of Calculation (Section 1)', 'Thermodynamics and Fluid Dynamics (Section 2)', 'Safety of Nuclear Installations - Methods, Analysis, Results (Section 3)', 'Front End and Back End of the Fuel Cycle, Radioactive Waste, Storage (Section 4)', 'Front End of the Fuel Cycle, Fuel Elements and Core Components (Section 5)', 'Operation of Nuclear Installations (Section 6)', 'Decommissioning of Nuclear Installations (Section 7)', 'Fusion Technology (Section 8)', 'Energy Industry and Economics (Section 10)', 'Radiation Protection (Section 11)', 'New Build and Innovations (Session New Build and Innovations, Section 12)', and 'Education, Expert Knowledge, Know-how-Transfer (Section 13)' have been covered in atw issues 10, 11 and 12 (2010). (orig.)

2009 annual meeting on nuclear technology. Pt. 1. Section reports

International Nuclear Information System (INIS)

Schaffrath, Andreas; Hartmann, Miks; Hoffmann, Petra Britt; Stieglitz, Robert; Hoehne, Thomas; Weiss, Frank-Peter; Hollands, Thorsten; Sanchez Espinoza, Victor Hugo; Tietsch, Wolfgang; Sonnenburg, H.G.

2009-01-01

Summary report on these 3 - out of 13 - Sessions of the Annual Conference on Nuclear Technology held in Dresden on May 12 to 14, 2009: Thermodynamics and Fluid Dynamics (Session 2), Safety of Nuclear Installations - Methods, Analysis, Results (Session 3), and, Front End of the Fuel Cycle, Fuel Elements and Core Components (Session 4). The other Sessions Reactor Physics and Methods of Calculation (Session 1), Front End and Back End of the Fuel Cycle, Radioactive Waste, Storage (Session 5), Operation of Nuclear Installations (Session 6), Decommissioning of Nuclear Installations (Session 7), Fusion Technology (Session 8), Research Reactors, Neutron Sources (Session 9), Energy Industry and Economics (Session 10), Radiation Protection (Session 11), New Build and Innovations (Session 12), and Education, Expert Knowledge, Know How Transfer (Session 13) have be covered in reports in further issues of atw. (orig.)

RF front-end world class designs

CERN Document Server

Love, Janine

2009-01-01

All the design and development inspiration and direction a harware engineer needs in one blockbuster book! Janine Love site editor for RF Design Line,columnist, and author has selected the very best RF design material from the Newnes portfolio and has compiled it into this volume. The result is a book covering the gamut of RF front end design from antenna and filter design fundamentals to optimized layout techniques with a strong pragmatic emphasis. In addition to specific design techniques and practices, this book also discusses various approaches to solving RF front end design problems and h

Out-of-core nuclear fuel cycle optimization utilizing an engineering workstation

International Nuclear Information System (INIS)

Turinsky, P.J.; Comes, S.A.

1986-01-01

Within the past several years, rapid advances in computer technology have resulted in substantial increases in their performance. The net effect is that problems that could previously only be executed on mainframe computers can now be executed on micro- and minicomputers. The authors are interested in developing an engineering workstation for nuclear fuel management applications. An engineering workstation is defined as a microcomputer with enhanced graphics and communication capabilities. Current fuel management applications range from using workstations as front-end/back-end processors for mainframe computers to completing fuel management scoping calculations. More recently, interest in using workstations for final in-core design calculations has appeared. The authors have used the VAX 11/750 minicomputer, which is not truly an engineering workstation but has comparable performance, to complete both in-core and out-of-core fuel management scoping studies. In this paper, the authors concentrate on our out-of-core research. While much previous work in this area has dealt with decisions concerned with equilibrium cycles, the current project addresses the more realistic situation of nonequilibrium cycles

Report of the international forum on nuclear energy, nuclear non-proliferation and nuclear security. Measures to ensure nuclear non-proliferation and nuclear security for the back end of nuclear fuel cycle and regional cooperation in Asia

International Nuclear Information System (INIS)

Tazaki, Makiko; Yamamura, Tsukasa; Suzuki, Mitsutoshi; Kuno, Yusuke; Mochiji, Toshiro

2013-03-01

The Japan Atomic Energy Agency (JAEA) held 'International Forum on Nuclear Energy, Nuclear Non-proliferation and Nuclear Security - Measures to ensure nuclear non-proliferation and nuclear security for the back end of nuclear fuel cycle and regional cooperation in Asia-' on 12 and 13 December 2012, co-hosted by the Japan Institute of International Affairs (JIIA) and School of Engineering, The University of Tokyo. In the forum, keynote speakers from Japan, International Atomic Energy Agency (IAEA), the U.S., France and Republic of Korea (ROK), respectively explained their efforts regarding peaceful use of nuclear energy and nuclear non-proliferation. In two panel discussions, entitled 'Measures to ensure nuclear non-proliferation and nuclear security of nuclear fuel cycle back end' and 'Measures to ensure nuclear non-proliferation and nuclear security for nuclear energy use in the Asian region and a multilateral cooperative framework', active discussions were made among panelists from Japan, IAEA, the U.S., France, ROK, Russia and Kazakhstan. This report includes abstracts of keynote speeches, summaries of two panel discussions and materials of the presentations in the forum. The editors take full responsibility for the wording and content of this report except presentation materials. (author)

Front-end electronics development for the SSC

International Nuclear Information System (INIS)

Levi, M.

1990-12-01

This is a status report on electronics development undertaken by the Front-End Electronics Collaboration. The overall goal of the collaboration remains the development by 1992 of complete, architecturally compatible, front end electronic systems for calorimeter, wire drift chamber, and silicon strip readout. We report here a few highlights to give a brief overview of the work underway. Performance requirements and capabilities, selected architectures, circuit designs and test results are presented. 13 refs., 21 figs., 1 tab

Indico front-end: From spaghetti to lasagna

CERN Multimedia

CERN. Geneva

2017-01-01

We will present how we transitioned from legacy spaghetti UI code to a more coherent, easier to understand and maintain ecosystem of front-end technologies and facilities with a strong emphasis in reusable components. In particular, we will share with you: 1) how we use Sass to maintain our home-baked CSS, 2) how we survive in 2017 without front-end Javascript frameworks, and 3) how we use template macros and WTForms for generating consistent HTML transparently.

A low-power front-end amplifier for the microstrip sensors of the PANDA microvertex detector

Energy Technology Data Exchange (ETDEWEB)

Di Pietro, Valentino; Brinkmann, Kai-Thomas; Riccardi, Alberto [II. Physikalisches Institut, JLU Giessen, Giessen (Germany); Rivetti, Angelo; Rolo, Manuel; Garbolino, Sara [INFN Sezione di Torino, Torino (Italy); Collaboration: PANDA-Collaboration

2014-07-01

The most common readout systems designed for nuclear physics detectors are based on amplitude measurements. The information that needs to be preserved is the charge delivered by a particle hitting the sensor. The electronic chain employed in these cases is made of two main building blocks: front-end amplifier and ADC. An issue in the implementation of such an architecture in scaled CMOS technologies is the dynamic range, because the charge information is extrapolated through the sampling of the peak of the front-end output signal. It is therefore interesting to explore the use of time-based architectures that offer better performances. In fact, in these topologies the linearity between the charge and the signal duration can be maintained even if some building blocks in the chain saturate. The main drawback is the loss in resolution since a duration measurement involves the difference between two time measurements. This work presents the design of a front-end optimized for fast Time-over-Threshold applications. The circuit has been developed for the microstrip detectors of the PANDA experiment. The architecture of the front-end amplifier is presented, and simulations in a 110 nm CMOS technology are discussed.

Performance of candu-6 fuel bundles manufactured in romania nuclear fuel plant

International Nuclear Information System (INIS)

Bailescu, A.; Barbu, A.; Din, F.; Dinuta, G.; Dumitru, I.; Musetoiu, A.; Serban, G.; Tomescu, A.

2013-01-01

The purpose of this article is to present the performance of nuclear fuel produced by Nuclear Fuel Plant (N.F.P.) - Pitesti during 1995 - 2012 and irradiated in units U1 and U2 from Nuclear Power Plant (N.P.P.) Cernavoda and also present the Nuclear Fuel Plant (N.F.P.) - Pitesti concern for providing technology to prevent the failure causes of fuel bundles in the reactor. This article presents Nuclear Fuel Plant (N.F.P.) - Pitesti experience on tracking performance of nuclear fuel in reactor and strategy investigation of fuel bundles notified as suspicious and / or defectives both as fuel element and fuel bundle, it analyzes the possible defects that can occur at fuel bundle or fuel element and can lead to their failure in the reactor. Implementation of modern technologies has enabled optimization of manufacturing processes and hence better quality stability of achieving components (end caps, chamfered sheath), better verification of end cap - sheath welding. These technologies were qualified by Nuclear Fuel Plant (N.F.P.) - Pitesti on automatic and Computer Numerical Control (C.N.C.) programming machines. A post-irradiation conclusive analysis which will take place later this year (2013) in Institute for Nuclear Research Pitesti (the action was initiated earlier this year by bringing a fuel bundle which has been reported defective by pool visual inspection) will provide additional information concerning potential damage causes of fuel bundles due to manufacturing processes. (authors)

Improved nuclear fuel element

International Nuclear Information System (INIS)

Klepfer, H.H.

1974-01-01

A nuclear fuel element is described which comprises: 1) an elongated clad container, 2) a layer of high lubricity material being disposed in and adjacent to the clad container, 3) a low neutron capture cross section metal liner being disposed in the clad container and adjacent to the layer, 4) a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, 5) an enclosure integrally secured and sealed at each end of the container, and a nuclear fuel material retaining means positioned in the cavity. (author)

Nuclear power generation and nuclear fuel

International Nuclear Information System (INIS)

Okajima, Yasujiro

1985-01-01

As of June 30, 1984, in 25 countries, 311 nuclear power plants of about 209 million kW were in operation. In Japan, 27 plants of about 19 million kW were in operation, and Japan ranks fourth in the world. The present state of nuclear power generation and nuclear fuel cycle is explained. The total uranium resources in the free world which can be mined at the cost below $130/kgU are about 3.67 million t, and it was estimated that the demand up to about 2015 would be able to be met. But it is considered also that the demand and supply of uranium in the world may become tight at the end of 1980s. The supply of uranium to Japan is ensured up to about 1995, and the yearly supply of 3000 st U 3 O 8 is expected in the latter half of 1990s. The refining, conversion and enrichment of uranium are described. In Japan, a pilot enrichment plant consisting of 7000 centrifuges has the capacity of about 50 t SWU/year. UO 2 fuel assemblies for LWRs, the working of Zircaloy, the fabrication of fuel assemblies, the quality assurance of nuclear fuel, the behavior of UO 2 fuel, the grading-up of LWRs and nuclear fuel, and the nuclear fuel business in Japan are reported. The reprocessing of spent fuel and plutonium fuel are described. (Kako, I.)

Idea management in support of pharmaceutical front end innovation

DEFF Research Database (Denmark)

Aagaard, Annabeth

2012-01-01

The pharmaceutical industry faces continuing pressures from rising R&D costs and depreciating value of patents, as patent lives is eroded by testing procedures and pressures from public authorities to cut health care costs. These challenges have increased the focus on shortening development times......, which again put pressure on the efficiency of front end innovation (FEI). In the attempt to overcome these various challenges pharmaceutical companies are looking for new models to support FEI. This paper explores in what way idea management can be applied as a tool in facilitation of front end...... innovation in practice. First I show through a literature study, how idea management and front end innovation are related and may support each other. Hereafter I apply an exploratory case study of front end innovation in eight medium to large pharmaceutical companies in examination of how idea management...

Front-end electronics for the upgraded GMRT

International Nuclear Information System (INIS)

Raut, Anil N; Bhalerao, Vilas; Kumar, A Praveen

2013-01-01

This paper first describes briefly the existing front-end receiver in use at the GMRT observatory and then details the ongoing development of next generation receiver systems for the upgraded GMRT. It covers the design of the new, two stage, room temperature, low noise amplifiers with better noise performance and matching, and improved dynamic range that are being implemented for the 130–260 MHz, 250–500 MHz and 550–900 MHz bands of the upgraded GMRT front-end systems.

Spent nuclear fuel storage device and spent nuclear fuel storage method using the device

International Nuclear Information System (INIS)

Tani, Yutaro

1998-01-01

Storage cells attachably/detachably support nuclear fuel containing vessels while keeping the vertical posture of them. A ventilation pipe which forms air channels for ventilating air to the outer circumference of the nuclear fuel containing vessel is disposed at the outer circumference of the nuclear fuel containing vessel contained in the storage cell. A shielding port for keeping the support openings gas tightly is moved, and a communication port thereof can be aligned with the upper portion of the support opening. The lower end of the transporting and containing vessel is placed on the shielding port, and an opening/closing shutter is opened. The gas tightness is kept by the shielding port, the nuclear fuel containing vessel filled with spent nuclear fuels is inserted to the support opening and supported. Then, the support opening is closed by a sealing lid. (I.N.)

Ultra-wideband wireless receiver front-end for high-speed indoor applications

Directory of Open Access Journals (Sweden)

Zhe-Yang Huang

2014-12-01

Full Text Available Low-noise, ultra-wideband (UWB wireless receiver front-end circuits were presented in this study. A two-stage common-source low-noise amplifier with wideband input impedance matching network, an active-balun and a double-balanced down-conversion mixer were adopted in the UWB wireless receiver front-end. The proposed wireless receiver front-end circuits were implemented in 0.18 μm radio-frequency-CMOS process. The maximum down-conversion power gain of the front-end is 25.8 dB; minimum single-sideband noise figure of the front-end is 4.9 dB over complete UWB band ranging from 3.1 to 10.6 GHz. Power consumption including buffers is 39.2 mW.

National Policy on Nuclear Fuel Cycle

International Nuclear Information System (INIS)

Soedyartomo, S.

1996-01-01

National policy on nuclear fuel cycle is aimed at attaining the expected condition, i.e. being able to support optimality the national energy policy and other related Government policies taking into account current domestic nuclear fuel cycle condition and the trend of international nuclear fuel cycle development, the national strength, weakness, thread and opportunity in the field of energy. This policy has to be followed by the strategy to accomplish covering the optimization of domestic efforts, cooperation with other countries, and or purchasing licences. These policy and strategy have to be broken down into various nuclear fuel cycle programmes covering basically assesment of the whole cycle, performing research and development of the whole cycle without enrichment and reprocessing being able for weapon, as well as programmes for industrialization of the fuel cycle stepwisery commencing with the middle part of the cycle and ending with the edge of the back-end of the cycle

Programmer's guide to FFE: a fast front-end data-acquisition program

International Nuclear Information System (INIS)

Million, D.L.

1983-05-01

The Large Coil Test Facility project of the Fusion Energy Division has a data acquisition system which includes a large host computer and several small, peripheral front-end computers. The front-end processors handle details of data acquisition under the control of the host and pass data back to the host for storage. Some of the front ends are known as fast front ends and are required to collect a maximum of 64,000 samples each second. This speed and other hardware constraints resulted in a need for a stand-alone, assembly language task which could be downline loaded from the host system into the fast front ends. FFE (Fast Front End) was written to satisfy this need. It was written in the PDP-11 MACRO-11 assembly language for an LSI-11/23 processor. After the host loads the task into the front end, it controls the data acquisition process with a series of commands and parameters. This Programmer's Guide describes the structure and operation of FFE in detail from a programming point of view. A companion User's guide provides more information on the use of the program from the host system

New approach to the optimization of nuclear fuel cycle - application of the goal programming and the AHP

International Nuclear Information System (INIS)

Kim, Poong Oh

1998-02-01

The front-end fuel cycle from mining to enrichment is in the maturity. Unlike the front-end fuel cycle, there are several pathways in the back-end fuel cycle. in this study five fuel cycle scenarios derived from a unique position in Korea of having a two-reactor programme of PWR and PHWR are proposed. In a selection of an optimal fuel cycle in a country, a number of attributes and factors that interact each other should be taken into account. Those factors to be considered in the study are categorized into two groups, one is tangible factor and the other is intangible factor. The major factors consist of minimizing fuel cycle cost, maximizing resource utilization, minimizing environmental impact and satisfying domestic and international politics. The long-term consequences of any decision for the back-end fuel cycle requires some sophisticated decision making tools. In this paper the Goal Programming method in combination with the Analytic Hierarchy Process (AHP) is applied in the decision making process. The Goal Programming is a very useful decision making tool to solve complex and multi-objective problems. The AHP, a method of solving complex decision problems with multiple attributes or objectives shows the strength in measuring the preferences of the attributes. In the study, the AHP is used for quantification of the intangible factors of which the evaluation is done by a team of nuclear experts. A model for fuel cycle selection is established in accordance with the logic of the Goal Programming. Also an interactive computer program is developed to obtain a solution for the most optimal fuel cycle in Korea

Separations in back-end of nuclear fuel cycle: overview of R and D activities

International Nuclear Information System (INIS)

Bansal, N.K.; Chitnis, R.R.

2004-01-01

This article discusses various areas in back-end of nuclear fuel cycle where R and D activities in separation science are actively pursued. Solvent extraction and ion-exchange are the main techniques where maximum developmental activities are underway. In addition to actual techniques, article also discusses the status of the studies especially where the process has been applied on larger scale. (author)

Direction of Nuclear Energy. Activity report 2010

International Nuclear Information System (INIS)

2011-11-01

This report proposes an overview of the research activities performed by the French DEN (Direction de l'Energie Nucleaire, Direction of Nuclear Energy) within the CEA. These activities address the future nuclear industrial systems (4. generation reactors, back-end of the future fuel cycle, basic scientific and technological research), the optimization of the industrial nuclear power (fuel cycle front end, second and third generation reactors, back-end of the present fuel cycle), major tools for the development of nuclear energy (simulation tools, Jules Horowitz reactor, value creation), clean up and dismantling of nuclear facilities (present status, the Passage project in Grenoble, the Aladin project in Fontenay-aux-Roses, projects at Marcoule, flow management of radioactive wastes, materials and disused fuels, transport). Three research centres are presented: Marcoule, Cadarache and Saclay

Economical Feedback of Increasing Fuel Enrichment on Electricity Cost for VVER-1000

Directory of Open Access Journals (Sweden)

Mohammed Saad Dwiddar

2015-08-01

Full Text Available A methodology of evaluating the economics of the front-end nuclear fuel cycle with a price change sensitivity analysis for a VVER-1000 reactor core as a case study is presented. The effect of increasing the fuel enrichment and its corresponding reactor cycle length on the energy cost is investigated. The enrichment component was found to represent the highly expenses dynamic component affecting the economics of the front-end fuel cycle. Nevertheless, the increase of the fuel enrichment will increase the reactor cycle length, which will have a positive feedback on the electricity generation cost (cent/KWh. A long reactor operation time with a cheaper energy cost set the nuclear energy as a competitive alternative when compared with other energy sources.

The importance for Bulgaria of multilateral approaches to the back-end of the nuclear fuel cycle

International Nuclear Information System (INIS)

Necheva, Ch.; McCombie, Ch.

2005-01-01

Bulgaria has a comparatively small nuclear program, but this provides a significant contribution of about 45% to the total electricity production in the country. There are 4 WWER units in operation at Kozloduy NPP and the national energy policy foresees construction of a further plant, Belene NPP. Further development of the nuclear option is dependent on the assurance of both fresh nuclear fuel supply and long-term management of spent fuel and high level waste. Because of the technical and economic challenges involved, international co-operation (bilateral and multilateral) in the back-end of the nuclear fuel cycle is a strategic issue of prime importance. This approach is very politically and socially sensitive at home and abroad and requires international consensus on the legal framework. For Bulgaria, as a producer of nuclear energy which relies on imported fresh nuclear fuel, an option of major interest is to seek a final solution for dealing with spent fuel in co-operation with the supplier of fresh fuel, i.e. Russia at present. But Bulgaria does not address only this option. In parallel, Kozloduy NPP is an organizational member of the international association ARIUS, established in 2002 in Baden, Switzerland. Thus the country also directly supports the mission of Arius, namely the promotion of concepts for safe, secure, economic and politically and socially acceptable regional and international storage and disposal of spent fuel and HLW. Bulgaria also participates directly in the SAPIERR project that was initiated by Arius under the 6 Framework Programme of the European Commission in order to study the concept of regional repositories to be shared by European partners. The range of Bulgarian waste management activities - including practical issues at the power plants, national studies on waste treatment, and involvement in the bilateral and multinational approaches described above - ensures that the country continues to maintain the necessary technical

Align the Front End First.

Science.gov (United States)

Perry, Jim

1995-01-01

Discussion of management styles and front-end analysis focuses on a review of Douglas McGregor's theories. Topics include Theories X, Y, and Z; leadership skills; motivational needs of employees; intrinsic and extrinsic rewards; and faulty implementation of instructional systems design processes. (LRW)

FACILITATING RADICAL FRONT-END INNOVATION THROUGH TARGETED HR PRACTICES

DEFF Research Database (Denmark)

Aagaard, Annabeth

2017-01-01

This study examines how radical front end innovation can be actively facilitated through selected and targeted HR practices and bundles of HR practices. The empirical field is an explorative case study of front end innovation and HR practices in the pharmaceutical industry, with an in-depth case ...

CMOS front-end electronics for radiation sensors

CERN Document Server

AUTHOR|(CDS)2071026

2015-01-01

This book offers a comprehensive treatment of front-end electronics for radiation detection. It discusses the fundamental principles of signal processing for radiation detectors and describes circuits at the level of functional building blocks, omitting transistor-level implementation. It also covers important system-level topics commonly found in the world of front-end electronics for radiation sensors. The book develops the topics in detail, with a constant focus on practical problems. It also provides real implementation examples that offer insights and stimuli for more experienced engineers already working in the field.

Front end readout electronics for the CMS hadron calorimeter

CERN Document Server

Shaw, Terri M

2002-01-01

The front-end electronics for the CMS Hadron Calorimeter provides digitized data at the beam interaction rate of 40 MHz. Analog signals provided by hybrid photodiodes (HPDs) or photomultiplier tubes (PMTs) are digitized and the data is sent off board through serialized fiber optic links running at 1600 Mbps. In order to maximize the input signal, the front-end electronics are housed on the detector in close proximity to the scintillating fibers or phototubes. To fit the electronics into available space, custom crates, backplanes and cooling methods have had to be developed. During the expected ten-year lifetime, the front-end readout electronics will exist in an environment where radiation levels approach 330 rads and the neutron fluence will be 1.3E11 n/cm sup 2. For this reason, the design approach relies heavily upon custom radiation tolerant ASICs. This paper will present the system architecture of the front-end readout crates and describe their results with early prototypes.

Front end readout electronics for the CMS hadron calorimeter

International Nuclear Information System (INIS)

Terri M. Shaw et al.

2002-01-01

The front-end electronics for the CMS Hadron Calorimeter provides digitized data at the beam interaction rate of 40 MHz. Analog signals provided by hybrid photodiodes (HPDs) or photomultiplier tubes (PMTs) are digitized and the data is sent off board through serialized fiber optic links running at 1600 Mbps. In order to maximize the input signal, the front-end electronics are housed on the detector in close proximity to the scintillating fibers or phototubes. To fit the electronics into available space, custom crates, backplanes and cooling methods have had to be developed. During the expected ten-year lifetime, the front-end readout electronics will exist in an environment where radiation levels approach 330 rads and the neutron fluence will be 1.3E11 n/cm 2 . For this reason, the design approach relies heavily upon custom radiation tolerant ASICs. This paper will present the system architecture of the front-end readout crates and describe their results with early prototypes

The back end of the nuclear fuel cycle: Technical and economic analysis-Part 2

International Nuclear Information System (INIS)

Roglans-Ribas, J.; Spinrad, B.I.

1990-01-01

The back end of the nuclear fuel cycle has been analyzed under current conditions in the United States, including the constraints imposed by the Nuclear Waste Policy Act of 1982 and its amendments. The scenarios for two closed cycles, a regular reprocessing cycle and a reprocessing scheme with cesium and strontium fractionation, are described. The storage of spent fuel discharged from the reactors and the disposal of reprocessed waste are studied for both reprocessing cycles. The economics of waste storage and disposal for the two closed cycles are compared with each other and with the reference once-through cycle. The results show that a standard reprocessing cycle results in the minimum cost for storage and disposal. When reporcessing costs are considered, the closed cycles can compete economically with the once-through cycle only if net reprocessing costs are very low

Closing the fuel cycle

International Nuclear Information System (INIS)

Aycoberry, C.; Rougeau, J.P.

1987-01-01

The progressive implementation of some key nuclear fuel cycle capecities in a country corresponds to a strategy for the acquisition of an independant energy source, France, Japan, and some European countries are engaged in such strategic programs. In France, COGEMA, the nuclear fuel company, has now completed the industrial demonstration of the closed fuel cycle. Its experience covers every step of the front-end and of the back-end: transportation of spent fuels, storage, reprocessing, wastes conditioning. The La Hague reprocessing plant smooth operation, as well as the large investment program under active progress can testify of full mastering of this industry. Together with other French and European companies, COGEMA is engaged in the recycling industry, both for uranium through conversion of uranyl nitrate for its further reeichment, and for plutonium through MOX fuel fabrication. Reprocessing and recycling offer the optimum solution for a complete, economic, safe and future-oriented fuel cycle, hence contributing to the necessary development of nuclear energy. (author)

Challenges in the front end of the uranium fuel cycle

International Nuclear Information System (INIS)

Seitz, Ken

2010-01-01

The long-term fundamentals for nuclear remain strong. Climate change and clean air concerns remain high on the agenda of national energy policies, as both developing and developed economies pursue a strategy of energy diversity and energy security. A global industry of 435 reactors is expected to grow to more than 639 reactors within the next 20 years with the potential for even more rapid expansion. This nuclear generating capacity relies on an international fuel cycle that can ensure stable and secure supply for decades to come. As the first step in the fuel cycle, the uranium industry has received various price signals over the past 5 decades, from the birth of an industry with strong demand and stock pile building and the associated robust pricing and new production stimulation, to an industry in decline and a period marked by liquidation of large inventories, to the recent resurgence of nuclear and the associated uranium price signals. In many ways, understanding the current uranium environment and the outlook for the industry requires some understanding of these phases of nuclear. The global nuclear fleet today needs about 65,000 tonnes of uranium per year to meet reactor feed requirements. Primary production meets about two thirds of this requirement while the remainder is drawn from secondary supply. Secondary supply can essentially be described as stockpiles of previously produced uranium. However, secondary supplies are finite and more primary production will be needed. From a long-term perspective, there is no question that there are sufficient uranium resources to support the nuclear industry for many years to come. The IAEA's 'Red Book' estimates that more than 5 million tonnes of known resources could potentially be developed at today's prices. This is enough to supply the global reactor fleet for almost 80 years at current usage rates. Recently higher uranium prices have resulted in some production increases although the rate of growth has been held

LWR FA burn up: A challenge to optimize the entire fuel cycle to assure the envisaged benefit

Energy Technology Data Exchange (ETDEWEB)

Peehs, M [Siemens AG Unternehmensbereich KWU, Erlangen (Germany)

1997-12-01

Commercial LWR fuel will be limited to a maximum of U-235 content of 5% since the front end of the fuel cycle is licensed and prepared for that maximal enrichment. BWR- and PWR-reloads can be designed achieving batch average burn up over 60 GWd/tHM. In Germany the batch average burn up will presumably increase to this level, since the reload market is requesting further reductions in the fuel cycle inventories. However, it must be noted that the envisaged benefit can only be assured if the entire fuel cycle is optimized. Not all steps in the fuel cycle will bring a positive contribution bu the balance of all individual contributions must realize the envisaged integral benefit. In order to increase the burn up of the nuclear fuel beneficially further R and D both in the front end as well as in the back end of the fuel cycle is needed. An underestimation of the front end/back end interfaces may consume all benefits gained from isolated front optimizations. Back end R and D must be at once concentrated to avoid conservative enveloping licensing for the subsequent steps in the back end of the fuel cycle. Increasing burn up in the front end means making more and more use of the structural materials reserves.

LWR FA burn up: A challenge to optimize the entire fuel cycle to assure the envisaged benefit

International Nuclear Information System (INIS)

Peehs, M.

1997-01-01

Commercial LWR fuel will be limited to a maximum of U-235 content of 5% since the front end of the fuel cycle is licensed and prepared for that maximal enrichment. BWR- and PWR-reloads can be designed achieving batch average burn up over 60 GWd/tHM. In Germany the batch average burn up will presumably increase to this level, since the reload market is requesting further reductions in the fuel cycle inventories. However, it must be noted that the envisaged benefit can only be assured if the entire fuel cycle is optimized. Not all steps in the fuel cycle will bring a positive contribution bu the balance of all individual contributions must realize the envisaged integral benefit. In order to increase the burn up of the nuclear fuel beneficially further R and D both in the front end as well as in the back end of the fuel cycle is needed. An underestimation of the front end/back end interfaces may consume all benefits gained from isolated front optimizations. Back end R and D must be at once concentrated to avoid conservative enveloping licensing for the subsequent steps in the back end of the fuel cycle. Increasing burn up in the front end means making more and more use of the structural materials reserves

Nuclear fuel element leak detection system

International Nuclear Information System (INIS)

John, C.D. Jr.

1978-01-01

Disclosed is a leak detection system integral with a wall of a building used to fabricate nuclear fuel elements for detecting radiation leakage from the nuclear fuel elements as the fuel elements exit the building. The leak detecting system comprises a shielded compartment constructed to withstand environmental hazards extending into a similarly constructed building and having sealed doors on both ends along with leak detecting apparatus connected to the compartment. The leak detecting system provides a system for removing a nuclear fuel element from its fabrication building while testing for radiation leaks in the fuel element

Nuclear fuel pellet transfer escalator

International Nuclear Information System (INIS)

Huggins, T.B. Sr.; Roberts, E.; Edmunds, M.O.

1991-01-01

This patent describes a nuclear fuel pellet escalator for loading nuclear fuel pellets into a sintering boat. It comprises a generally horizontally-disposed pellet transfer conveyor for moving pellets in single file fashion from a receiving end to a discharge end thereof, the conveyor being mounted about an axis at its receiving end for pivotal movement to generally vertically move its discharge end toward and away from a sintering boat when placed below the discharge end of the conveyor, the conveyor including an elongated arm swingable vertically about the axis and having an elongated channel recessed below an upper side of the arm and extending between the receiving and discharge ends of the conveyor; a pellet dispensing chute mounted to the arm of the conveyor at the discharge end thereof and extending therebelow such that the chute is carried at the discharge end of the conveyor for generally vertical movement therewith toward and away from the sintering boat

Nuclear Energy Division. 2009 Activity report

International Nuclear Information System (INIS)

2009-01-01

After a presentation of the future investment programme of the nuclear energy department at the French national Nuclear Research Center (CEA), this report proposes a description of tomorrow's industrial nuclear systems (back-end of future fuel cycle, fourth generation systems, basic scientific and technological research), describes how current nuclear industrial systems are optimized (front-end and back-end of fuel cycle, second and third generation reactors). It presents the main tools for nuclear development: simulation programme, the Jules Horowitz reactor project, maintenance of specific facilities, research valorisation. It reports the activities related to the clean-up and dismantling in different nuclear sites, presents the activities of CEA's nuclear research centres (Saclay, Cadarache, Marcoule), briefly presents the transverse material programme, recalls some events, and gives some key figures

Radiation hardness on very front-end for SPD

International Nuclear Information System (INIS)

Cano, Xavier; Graciani, Ricardo; Gascon, David; Garrido, Lluis; Bota, Sebastia; Herms, Atila; Comerma, Albert; Riera, Jordi

2005-01-01

The calorimeter front-end electronics of the LHCb experiment will be located in a region, which is not protected from radiation. Therefore, all the electronics must be qualified to stand some defined radiation levels. The procedure, measurements and results of an irradiation test for every component of the very front-end SPD detector, which is part of the LHCb calorimeter are presented here. All the tested components, except a custom made ASIC, are commercially available

Nuclear fuel assembly

International Nuclear Information System (INIS)

Wakamatsu, Mitsuo.

1974-01-01

Object: To improve a circulating flow passage of coolant so as to be able to accurately detect the temperature of coolant, rare gases contained, and the like. Structure: A fuel assembly comprising a flow regulating lattice provided with a plurality of communication holes in an axial direction, said lattice being positioned at the upper end of an outer tube in which nuclear fuel elements are received, and a neutron shielding body having a plurality of spiral coolant flow passages disposed between the lattice and the nuclear fuel elements, whereby a coolant comprised of liquid sodium or the like, which moves up passing through the coolant flow passages and the flow regulating passage, is regulated and passed through a detector mounted at the upper part of the flow regulating lattice to detect coolant temperature, flow rate, and rare gases or the like as the origin of nuclear fission contained in the coolant due to breakage of fuel elements. (Kamimura, M.)

Digital front-end electronics for COMPASS Muon-Wall 1 detector

International Nuclear Information System (INIS)

Alekseev, G.D.; Zhuravlev, N.I.; Maggiora, A.

2005-01-01

The digital front-end electronics for the COMPASS Muon-Wall 1 (CERN) detector is described. The digital card has been designed on the basis of the TDC chip F1. One card includes 6 F1 chips (192 channels), bus arbiter, DAC, power supply distribution, hot-link interface. The total number of the digital cards in the system is 44 housed in 5 euro-crates (6U), the total number of readout channels is 8448. The electronics has been designed by the Dzhelepov Laboratory of Nuclear Problems (JINR) and INFN (Torino, Italy) experts

Investigation and analysis of nuclear fuel cycle back-end technology development

International Nuclear Information System (INIS)

Song, Kee Chan

2012-01-01

The R and D status of the nuclear fuel cycle beckoned was investigated and analyzed for Korea and overseas nuclear countries. The technical achievement and future plan of Korea were outlined, and up-to-date R and D status and strategies of overseas nuclear countries were investigated and analyzed. Ο United States Ο France and European Union Ο Japan Ο Russia Ο China And the recent trend of the multilateral approach in the nuclear fuel cycle backoned was arranged

Fuel fabrication and reprocessing for nuclear fuel cycle with inherent safety demands

Energy Technology Data Exchange (ETDEWEB)

Shadrin, Andrey Yurevich; Dvoeglazov, Konstantin Nikolaevich; Ivanov, Valentine Borisovich; Volk, Vladimir Ivanovich; Skupov, Mikhail Vladimirovich; Glushenkov, Alexey Evgenevich [Joint Stock Company ' ' The High Technological Research Institute of Inorganic Materials' ' , Moscow (Russian Federation); Troyanov, Vladimir Mihaylovich; Zherebtsov, Alexander Anatolievich [Innovation and Technology Center of Project ' ' PRORYV' ' , State Atomic Energy Corporation ' ' Rosatom' ' , Moscow (Russian Federation)

2015-06-01

The strategies adopted in Russia for a closed nuclear fuel cycle with fast reactors (FR), selection of fuel type and recycling technologies of spent nuclear fuel (SNF) are discussed. It is shown that one of the possible technological solutions for the closing of a fuel cycle could be the combination of pyroelectrochemical and hydrometallurgical methods of recycling of SNF. This combined scheme allows: recycling of SNF from FR with high burn-up and short cooling time; decreasing the volume of stored SNF and the amount of plutonium in a closed fuel cycle in FR; recycling of any type of SNF from FR; obtaining the high pure end uranium-plutonium-neptunium end-product for fuel refabrication using pellet technology.

MMIC tuned front-end for a coherent optical receiver

DEFF Research Database (Denmark)

Petersen, Anders Kongstad; Jagd, A. M.; Ebskamp, F.

1993-01-01

A low-noise transformer tuned optical front-end for a coherent optical receiver is described. The front-end is based on a GaInAs/InP p-i-n photodiode and a full custom designed GaAs monolithic microwave integrated circuit (MMIC). The measured equivalent input noise current density is between 5-16 p...

Proceedings of the Topical meeting on the reactor fuel performance - TopFuel 2012 Transactions

International Nuclear Information System (INIS)

2012-01-01

TopFuel is an annual topical meeting organised by ENS, the American Nuclear Society and the Atomic Energy Society of Japan. TopFuel's primary objective is to bring together leading specialists in the field from around the world to analyse advances in nuclear fuel management technology and to use the findings of the latest cutting-edge research to help manufacture the high performance nuclear fuels of today and tomorrow. Aim is to discuss the challenges facing the developers and manufacturers of new high-performance nuclear fuels - fuels that will help meet current and future energy demand and reduce man's over dependence upon CO 2 -emitting fossil fuels. The technical scope of Top Fuel 2012 includes all aspects of nuclear fuel from fuel rod to core design as well as manufacturing, performance in commercial and test reactors or on-going and future developments and trends. The meeting includes selectively front and/or back end issues that impact fuel designs and performance. (authors)

2010 ANNUAL MEETING ON NUCLEAR TECHNOLOGY. Pt. 3. Section reports; JAHRESTAGUNG KERNTECHNIK 2010. T. 3. Sektionsberichte Technische Sitzungen

Energy Technology Data Exchange (ETDEWEB)

Arnold, Uwe; Baumann, Erik [AREVA NP GmbH, Erlangen (Germany); Fischer, Ulrich; Bohnstedt, Angelika [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany); Gehring, Michael [Babcock Noell GmbH, Wuerzburg (Germany); Roedig, Manfred [Forschungszentrum Juelich GmbH (Germany); Willschuetz, Hans-Georg [E.ON Kernkraft GmbH, Hannover (Germany); Goers, Stefan [TUEV NORD SysTec GMbH und Co. KG, Hamburg (Germany); Schoenfelder, Christian [AREVA NP GmbH, Offenbach (Germany)

2010-12-15

Summary report on these 6 - out of 12 - Sessions of the Annual Conference on Nuclear Technology held in Berlin on May 3 to 6, 2010: - Decommissioning of Nuclear Installations (Session 7), - Fusion Technology (Session 8), - Energy Industry and Economics (Session 10), - Radiation Protection (Session 11), - New Build and Innovations (Session 12), and - Education, Expert Knowledge, Know-how-Transfer (Session 13). The other Sessions: - Reactor Physics and Methods of Calculation (Session 1), - Thermodynamics and Fluid Dynamics (Session 2), - Safety of Nuclear Installations - Methods, Analysis, Results (Session 3), - Front End and Back End of the Fuel Cycle, Radioactive Waste, Storage (Session 4), - Front End of the Fuel Cycle, Fuel Elements and Core Components (Session 5), - Operation of Nuclear Installations (Session 6) have been covered in atw issues 10 and 11 (2010). (orig.)

Front-end Electronics for Unattended Measurement (FEUM). Results of Prototype Evaluation

Energy Technology Data Exchange (ETDEWEB)

Conrad, Ryan C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Keller, Daniel T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, Scott J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Leon E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-07-01

The International Atomic Energy Agency (IAEA) deploys unattended monitoring systems to provide continuous monitoring of nuclear material within safeguarded facilities around the world. As the number of unattended monitoring instruments increases, the IAEA is challenged to become more efficient in the implementation of those systems. In 2010, the IAEA initiated the Front-End Electronics for Unattended Measurement (FEUM) project with the goals of greater flexibility in the interfaces to various sensors and data acquisition systems, and improved capabilities for remotely located sensors (e.g., where sensor and front-end electronics might be separated by tens of meters). In consultation with the IAEA, a technical evaluation of a candidate FEUM device produced by a commercial vendor has been performed. This evaluation assessed the device against the IAEA’s original technical specifications and a broad range of important parameters that include sensor types, cable lengths and types, industrial electromagnetic noise that can degrade signals from remotely located detectors, and high radiation fields. Testing data, interpretation, findings and recommendations are provided.

2009 annual meeting on nuclear technology. Pt. 1. Section reports; JAHRESTAGUNG KERNTECHNIK 2009. T. 1. Sektionsberichte

Energy Technology Data Exchange (ETDEWEB)

Schaffrath, Andreas [TUeV NORD SysTec GmbH und Co. KG, Hamburg (Germany); Hartmann, Miks; Hoffmann, Petra Britt [Areva NP GmbH, Erlangen (Germany); Stieglitz, Robert [Forschungszentrum Karlsruhe, Eggenstein-Leopoldshafen (Germany); Hoehne, Thomas [Forschungszentrum Dresden-Rossendorf, Dresden (Germany); Weiss, Frank-Peter [Forschungszentrum Dresden-Rossendorf, Inst. fuer Sicherheitsforschung, Dresden (Germany); Hollands, Thorsten [Ruhr-Univ. Bochum (RUB), Energy Systems and Energy Economics (LEE), Bochum (Germany); Sanchez Espinoza, Victor Hugo [Forschungszentrum Karlsruhe, Inst. fuer Reaktorsicherheit, Eggenstein-Leopoldshafen (Germany); Tietsch, Wolfgang [Westinghouse Electric Germany GmbH, Mannheim (Germany); Sonnenburg, H.G. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Muenchen (Germany)

2009-08-15

Summary report on these 3 - out of 13 - Sessions of the Annual Conference on Nuclear Technology held in Dresden on May 12 to 14, 2009: Thermodynamics and Fluid Dynamics (Session 2), Safety of Nuclear Installations - Methods, Analysis, Results (Session 3), and, Front End of the Fuel Cycle, Fuel Elements and Core Components (Session 4). The other Sessions Reactor Physics and Methods of Calculation (Session 1), Front End and Back End of the Fuel Cycle, Radioactive Waste, Storage (Session 5), Operation of Nuclear Installations (Session 6), Decommissioning of Nuclear Installations (Session 7), Fusion Technology (Session 8), Research Reactors, Neutron Sources (Session 9), Energy Industry and Economics (Session 10), Radiation Protection (Session 11), New Build and Innovations (Session 12), and Education, Expert Knowledge, Know How Transfer (Session 13) have be covered in reports in further issues of atw. (orig.)

40 CFR 63.487 - Batch front-end process vents-reference control technology.

Science.gov (United States)

2010-07-01

... § 63.487 Batch front-end process vents—reference control technology. (a) Batch front-end process vents... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents-reference control technology. 63.487 Section 63.487 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

Land and Water Use, CO2 Emissions, and Worker Radiological Exposure Factors for the Nuclear Fuel Cycle

Energy Technology Data Exchange (ETDEWEB)

Brett W Carlsen; Brent W Dixon; Urairisa Pathanapirom; Eric Schneider; Bethany L. Smith; Timothy M. AUlt; Allen G. Croff; Steven L. Krahn

2013-08-01

The Department of Energy Office of Nuclear Energy’s Fuel Cycle Technologies program is preparing to evaluate several proposed nuclear fuel cycle options to help guide and prioritize Fuel Cycle Technology research and development. Metrics are being developed to assess performance against nine evaluation criteria that will be used to assess relevant impacts resulting from all phases of the fuel cycle. This report focuses on four specific environmental metrics. • land use • water use • CO2 emissions • radiological Dose to workers Impacts associated with the processes in the front-end of the nuclear fuel cycle, mining through enrichment and deconversion of DUF6 are summarized from FCRD-FCO-2012-000124, Revision 1. Impact estimates are developed within this report for the remaining phases of the nuclear fuel cycle. These phases include fuel fabrication, reactor construction and operations, fuel reprocessing, and storage, transport, and disposal of associated used fuel and radioactive wastes. Impact estimates for each of the phases of the nuclear fuel cycle are given as impact factors normalized per unit process throughput or output. These impact factors can then be re-scaled against the appropriate mass flows to provide estimates for a wide range of potential fuel cycles. A companion report, FCRD-FCO-2013-000213, applies the impact factors to estimate and provide a comparative evaluation of 40 fuel cycles under consideration relative to these four environmental metrics.

THREE PERSPECTIVES ON MANAGING FRONT END INNOVATION

DEFF Research Database (Denmark)

Jensen, Anna Rose Vagn; Clausen, Christian; Gish, Liv

2018-01-01

as a complementary perspective. The paper combines a literature review with an empirical examination of the application of these multiple perspectives across three cases of front end of innovation (FEI) management in mature product developing companies. While the process models represent the dominant, albeit rather...... to represent an emergent approach in managing FEI where process models, knowledge strategies and objects become integrated elements in more advanced navigational strategies for key players.......This paper presents three complementary perspectives on the management of front end innovation: A process model perspective, a knowledge perspective and a translational perspective. While the first two perspectives are well established in literature, we offer the translation perspective...

REASONING IN THE FUZZY FRONT END OF INNOVATION:

DEFF Research Database (Denmark)

Haase, Louise Møller; Laursen, Linda Nhu

2018-01-01

in the fuzzy front end is the reasoning process: innovation teams are faced with open-ended, ill-defined problems, where they need to make decisions about an unknown future but have only incomplete, ambiguous and contradicting insights available. We study the reasoning of experts, how they frame to make sense...... of all the insights and create a basis for decision-making in relation to a new project. Based on case studies of five innovative products from various industries, we propose a Product DNA model for understanding the reasoning in the fuzzy front end of innovation. The Product DNA Model explains how...... experts reason and what direct their reasoning....

Device for detecting defective nuclear reactor fuel rods

International Nuclear Information System (INIS)

Steven, J.

1976-01-01

A moisture sensor is provided for a nuclear fuel rod for water-cooled nuclear reactors wherein moisture can be present. The fuel rod has an end cap and a charge of nuclear fuel. The moisture sensor is disposed between the end cap and the charge and serves to detect a leak in the fuel rod. The moisture sensor includes a capsule-like housing having an inner space and having openings through which moisture can pass into the inner space in the event of a leak in the fuel rod. Ferromagnetic material is disposed in the inner space of the housing together with a moisture detector responsive to moisture for altering the diposition of the ferromagnetic material in the inner space. 5 claims, 6 drawing figures

The study on the methods for improving the gredibility of NDT equipment for the gap of pellets of nuclear fuel rods

International Nuclear Information System (INIS)

Zhang Lei; Liu Ming; Wang Changhong; Ma Jinbo

2014-01-01

In order to improve the credibility of the new generation of automatic online non-destructive testing equipment for the gap of the pellets of nuclear fuel rods the researchers have done a lot of work in the development of the device. Such measures as multi-thread synchronization, precise timing, upper and lower computer communication control, antijamming processing are adopted such that the detecting device can accurately detecte the size of the gap between pellets, the position and length of the spring cavity at the front end of the nuclear fuel rods at a detection rate of 8 m/min. The detection credibility for the 0.5 mm gap is over 95%, reaching the international advanced level. At present, the device is put into use in the nuclear fuel element production line. (authors)

Terahertz performance of quasioptical front-ends with a hotelectron bolometer

International Nuclear Information System (INIS)

Semenov, A; Richter, H; Guenther, B; Huebers, H-W; Karamarkovic, J

2006-01-01

We present terahertz performance of quasioptical front-ends consisting of a hotelectron bolometer imbedded in a planar feed antenna and integrated with an immersion lens. The impedance and radiation pattern of the log-spiral and double-slot planar feeds are evaluated using the method of moments; the collimating action of the lens is modelled using the physical optics. The total efficiency of the front-ends is computed taking into account frequency dependent impedance of the bolometer. Measured performance of the front-ends qualifies the simulation technique as a reliable tool for the design of terahertz receivers

Technical considerations in repowering a nuclear plant for fossil fueled operation

International Nuclear Information System (INIS)

Patti, F.J.

1996-01-01

Repowering involves replacement of the reactor by a fossil fuel source of steam. This source can be a conventional fossil fueled boiler or the heat recovery steam generator (HRSG) on a gas turbine exhaust. The existing steam turbine plant is used to the extent possible. Alternative fuels for repowering a nuclear plant are coal, natural gas and oil. In today's world oil is not usually an alternative. Selection of coal or natural gas is largely a matter of availability of the fuel near the location of the plant. Both the fossil boiler and the HRSG produce steam at higher pressures and temperatures than the throttle conditions for a saturated steam nuclear turbine. It is necessary to match the steam conditions from the new source to the existing turbine as closely as possible. Technical approaches to achieve a match range from using a topping turbine at the front end of the cycle to attemperation of the throttle steam with feedwater. The electrical output from the repowered plant is usually greater than that of the original nuclear fueled design. This requires consideration of the ability to use the excess electricity. Interfacing of the new facility with the existing turbine plant requires consideration of facility layout and design. Site factors must also be considered, especially for a coal fired boiler, since rail and coal handling facilities must be added to a site for which these were not considered. Additional site factors that require consideration are ash handling and disposal

Dry refabrication technology development of spent nuclear fuel

International Nuclear Information System (INIS)

Park, Geun Il; Lee, J. W.; Song, K. C.

2012-04-01

Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed

Dry refabrication technology development of spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Park, Geun Il; Lee, J. W.; Song, K. C.; and others

2012-04-15

Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed.

An Alternative Front End Analysis Strategy for Complex Systems

Science.gov (United States)

2014-12-01

missile ( ABM ) system . Patriot is employed in the field through a battalion echelon organizational structure. The line battery is the basic building...Research Report 1981 An Alternative Front End Analysis Strategy for Complex Systems M. Glenn Cobb U.S. Army Research Institute...NUMBER W5J9CQ11D0003 An Alternative Front End Analysis Strategy for Complex Systems 5b. PROGRAM ELEMENT NUMBER 633007 6

OECD/NEA study on economics of the Back-end of the Nuclear Fuel Cycle

International Nuclear Information System (INIS)

Lokhov, Alexey; Urso, Maria Elena; Cameron, Ron

2013-01-01

Recommendations: 1. While there may be reasons to extend the interim storage of SNF, these should not prevent governments from maintaining vigorous efforts towards the establishment of deep geological repositories, thereby addressing legitimate public expectations and fulfilling the “intergenerational equity” principle. 2. Public involvement in the establishment and implementation of the SNF management strategy is considered vital: mechanisms to improve stakeholder participation and transparency should be a high priority. 3. Governments should continue to be vigilant in ensuring that the funding systems adopted are stable and robust and that financial resources accrued by waste producers for the management of their waste will be adequate and available at the time they are needed. The following features are considered essential: – Regular and frequent reviews to allow for newly accrued knowledge on technical aspects and actual fund developments, as well as other qualitative factors (e.g. sociopolitical), to be taken into account, and, importantly, for emerging shortfalls to be swiftly addressed through the necessary corrective actions. – Ring-fencing of funds to ensure that resources are only used for the intended purposes. 4. For countries that are committed to ongoing use or development of nuclear energy, comparisons of the costs of different strategies for managing the back end should be drawn on the basis of the full fuel cycle cost. For countries which are phasing out or have already exited nuclear power, a direct back-end cost comparison may be more appropriate. In any case, assessments made for total or partial FC cost comparisons should be transparent about the assumptions made and the scope of the analysis. 5. In any decision-making process regarding the choice of SNF management strategy, a multicriteria approach should be adopted at the national level that expands the quantitative economic considerations to include qualitative factors. These can

Long island to Limerick, nuclear fuel transfer

International Nuclear Information System (INIS)

Jones, Bill

1999-01-01

The issue described is: how to move 33 shipments of radioactive nuclear fuel - 200 tons of enriched uranium pellets - on rail cars through the heart of Philadelphia, without upsetting politicians, the media and anti-nuclear activists, after a similar plan to move the fuel through New York City had been rejected in a political disaster. The answer to this is: Strategic Communications Planning. At PECO Energy's department of Corporate and Public Affairs, the research is quite clear that in risk management situations like this, the side that gets out front with the most credible information inevitably wins. That is exactly what was set out to do

Nuclear fuel cycles : description, demand and supply estimates

International Nuclear Information System (INIS)

Gadallah, A.A.; Abou Zahra, A.A.; Hammad, F.H.

1985-01-01

This report deals with various nuclear fuel cycles description as well as the world demand and supply estimates of materials and services. Estimates of world nuclear fuel cycle requirements: nuclear fuel, heavy water and other fuel cycle services as well as the availability and production capabilities of these requirements, are discussed for several reactor fuel cycle strategies, different operating and under construction fuel cycle facilities in some industrialized and developed countries are surveyed. Various uncertainties and bottlenecks which are recently facing the development of some fuel cycle components are also discussed, as well as various proposals concerning fuel cycle back-end concepts. finally, the nuclear fuel cycles activities in some developing countries are reviewed with emphasis on the egyptian plans to introduce nuclear power in the country. 11 fig., 16 tab

Characterization of front-end electronics for CZT based handheld radioisotope identifier

Energy Technology Data Exchange (ETDEWEB)

Lombigit, L., E-mail: lojius@nm.gov.my [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Rahman, Nur Aira Abd; Mohamad, Glam Hadzir Patai; Ibrahim, Maslina Mohd; Yussup, Nolida; Yazid, Khairiah; Jaafar, Zainudin

2016-01-22

A radioisotope identifier device based on large volume Co-planar grid CZT detector is current under development at Malaysian Nuclear Agency. This device is planned to be used for in-situ identification of radioisotopes based on their unique energies. This work reports on electronics testing performed on the front-end electronics (FEE) analog section comprising charge sensitive preamplifier-pulse shaping amplifier chain. This test involves measurement of charge sensitivity, pulse parameters and electronics noise. This report also present some preliminary results on the spectral measurement obtained from gamma emitting radioisotopes.

Sustainability in the front-end of innovation at design agencies

NARCIS (Netherlands)

Storaker, A.; Wever, R.; Dewulf, K.; Blankenburg, D.

2013-01-01

In the two last decades a considerable amount of research has been conducted on the Front End of Innovation. This is the stage of the product development process where the design brief is formulated. This phase is argued to be crucial to the success of the final product. While the Front End of

TDC for the front end architecture in the PANDA MVD

Energy Technology Data Exchange (ETDEWEB)

Riccardi, Alberto; Brinkmann, Kai Thomas; Di Pietro, Valentino [II Physikalisches Institut Justus-Liebig-Universitaet Giessen, Giessen (Germany); Garbolino, Sara; Rivetti, Angelo; Rolo, Manuel [INFN Sezione di Torino, Torino (Italy); Collaboration: PANDA-Collaboration

2014-07-01

In nuclear detectors the information on the energy of the particle is usually obtained by measuring the amplitude of the signal delivered by the sensor. The low voltage power supply used in modern deep submicron technologies constrains the maximum dynamic range of the ADC. So we can obtain the energy information with time-based techniques, in which the energy is associated with the duration of the signal through the Time over Threshold method. This work is focused on the PANDA Micro Vertex Detector and explores the possibility of applying a time-based readout approach for the microstrip sensors. In PANDA, the strip system must cope with hit rates up to 50 kHz per channel. Therefore, the front-end output must be relatively short. This implies that the clock resolution is not enough to measure the signal duration, so it is necessary to use a Time to Digital Converter. The front-end and the TDC structure are designed in a 0.11μm CMOS process. The TDC chosen is based on an analog clock interpolator because it combines good time resolution with a fairly simple implementation and low power consumption. In the presentation the architectures are described and the challenges associated to its implementation discussed.

Transport device for nuclear fuel powder

International Nuclear Information System (INIS)

Adelmann, M.

1987-01-01

The transport device for nuclear fuel powder, which does not disintegrate during transport, has a transport pipe which starts with its entry end from the floor or a closed container and opens with its outlet end at the top into a closed separation container connect via a powder filter to a suction pump. By alternate regular opening and closing of a first control valve for transport gas fitted to a transport pipe to a supply duct and a second control valve for transport gas fitted to the container to an additional supply duct, alternating plugs of nuclear fuel powder and transport gas cushions are formed and are transported to the outlet end of the transport pipe. (orig./HP) [de

Nuclear fuel cycle scenarios at CGNPC

International Nuclear Information System (INIS)

Xiao, Min; Zhou, Zhou; Nie, Li Hong; Mao, Guo Ping; Hao, Si Xiong; Shen, Kang

2008-01-01

Established in 1994, China Guangdong Nuclear Power Holding Co. (CGNPC) now owns two power stations GNPS and LNPS Phase I, with approximate 4000 MWe of installed capacity. With plant upgrades, advanced fuel management has been introduced into the two plants to improve the plant economical behavior with the high burnup fuel implemented. For the purpose of sustainable development, some preliminary studies on nuclear fuel cycle, especially on the back-end, have been carried out at CGNPC. According to the nuclear power development plan of China, the timing for operation and the capacity of the reprocessing facility are studied based on the amount of the spent fuel forecast in the future. Furthermore, scenarios of the fuel cycles in the future in China with the next generation of nuclear power were considered. Based on the international experiences on the spent fuel management, several options of spent fuel reprocessing strategies are investigated in detail, for example, MOX fuel recycling in light water reactor, especially in the current reactors of CGNPC, spent fuel intermediated storage, etc. All the investigations help us to draw an overall scheme of the nuclear fuel cycle, and to find a suitable road-map to achieve the sustainable development of nuclear power. (authors)

Development of System Engineering Technology for Nuclear Fuel Cycle

International Nuclear Information System (INIS)

Kim, Hodong; Choi, Iljae

2013-04-01

The development of efficient process for spent fuel and establishment of system engineering technology to demonstrate the process are required to develop nuclear energy continuously. The demonstration of pyroprocess technology which is proliferation resistance nuclear fuel cycle technology can reduce spent fuel and recycle effectively. Through this, people's trust and support on nuclear power would be obtained. Deriving the optimum nuclear fuel cycle alternative would contribute to establish a policy on back-end nuclear fuel cycle in the future, and developing the nuclear transparency-related technology would contribute to establish amendments of the ROK-U. S. Atomic Energy Agreement scheduled in 2014

Nuclear fuel pellet loading machine

International Nuclear Information System (INIS)

Dazen, J.R.; Denero, J.V.

1976-01-01

A nuclear fuel pellet loading machine is described including an inclined rack mounted on a base and having parallel spaced grooves on its upper surface arranged to support fuel rods. A fuel pellet tray is adapted to be placed on a table spaced from the rack, the tray having columns of fuel pellets which are in alignment with the open ends of fuel rods located in the rack grooves. A transition plate is mounted between the fuel rod rack and the fuel pellet tray to receive and guide the pellets into the open ends of the fuel rods. The pellets are pushed into the fuel rods by a number of mechanical fingers mounted on a motor operated block which is moved along the pellet tray length by a drive screw driven by the motor. To facilitate movement of the pellets in the fuel rods the rack is mounted on a number of spaced vibrators which vibrate the fuel rods during fuel pellet insertion. A pellet sensing device movable into an end of each fuel rod indicates to an operator when each rod has been charged with the correct number of pellets

Multilateral controls of nuclear fuel-cycle in Asia

International Nuclear Information System (INIS)

Choi, Jor-Shan

2010-01-01

To meet increasing energy demand and climate change issues, nuclear energy is expected to expand during the next decades in both developed and developing countries. This expansion, most visibly in Asian countries would no doubt be accompanied with complex and intractable challenges to global peace and security, notably in the back-end of the nuclear fuel cycle. What to do with the growing stocks of spent fuel in existing nuclear programs? And how to reduce proliferation concerns when spent fuels are generated in less stable regions of the world? The answers to these questions may lie in the possibility of multilateral (or regional) control of nuclear materials and technologies in the back-end of nuclear fuel cycle. One of the areas of interest is technology, e.g., spent fuel treatment (reprocessing) for long term sustainability and environmental-friendly disposal of radioactive wastes, as an alternative to directly disposing spent fuel in geologic repository. The other is to seek for regional centers for centralized interim spent fuel storage which can eventually turn into disposal facilities. Such centers could help facilitate the possibilities of spent fuel take-back/take-away from countries located in less stable regions for fix-period storage. (author)

Test of ATLAS RPCs Front-End electronics

International Nuclear Information System (INIS)

Aielli, G.; Camarri, P.; Cardarelli, R.; Di Ciaccio, A.; Di Stante, L.; Liberti, B.; Paoloni, A.; Pastori, E.; Santonico, R.

2003-01-01

The Front-End Electronics performing the ATLAS RPCs readout is a full custom 8 channels GaAs circuit, which integrates in a single die both the analog and digital signal processing. The die is bonded on the Front-End board which is completely closed inside the detector Faraday cage. About 50 000 FE boards are foreseen for the experiment. The complete functionality of the FE boards will be certificated before the detector assembly. We describe here the systematic test devoted to check the dynamic functionality of each single channel and the selection criteria applied. It measures and registers all relevant electronics parameters to build up a complete database for the experiment. The statistical results from more than 1100 channels are presented

A dynamic, dependent type system for nuclear fuel cycle code generation

Energy Technology Data Exchange (ETDEWEB)

Scopatz, A. [The University of Chicago 5754 S. Ellis Ave, Chicago, IL 60637 (United States)

2013-07-01

The nuclear fuel cycle may be interpreted as a network or graph, thus allowing methods from formal graph theory to be used. Nodes are often idealized as nuclear fuel cycle facilities (reactors, enrichment cascades, deep geologic repositories). With the advent of modern object-oriented programming languages - and fuel cycle simulators implemented in these languages - it is natural to define a class hierarchy of facility types. Bright is a quasi-static simulator, meaning that the number of material passes through a facility is tracked rather than natural time. Bright is implemented as a C++ library that models many canonical components such as reactors, storage facilities, and more. Cyclus is a discrete time simulator, meaning that natural time is tracked through out the simulation. Therefore a robust, dependent type system was developed to enable inter-operability between Bright and Cyclus. This system is capable of representing any fuel cycle facility. Types declared in this system can then be used to automatically generate code which binds a facility implementation to a simulator front end. Facility model wrappers may be used either internally to a fuel cycle simulator or as a mechanism for inter-operating multiple simulators. While such a tool has many potential use cases it has two main purposes: enabling easy performance of code-to-code comparisons and the verification and the validation of user input.

Light-front nuclear shell-model

International Nuclear Information System (INIS)

Johnson, M.B.

1990-01-01

I examine the effects of nuclear structure on high-energy, high-momentum transfer processes, specifically the EMC effect. For pedagogical reasons, a fictitious but simple two-body system consisting of two equal-mass particles interacting in a harmonic oscillator potential has been chosen. For this toy nucleus, I utilize a widely-used link between instant-form and light-front dynamics, formulating nuclear structure and deep-inelastic scattering consistently in the laboratory system. Binding effects are compared within conventional instant-form and light-front dynamical frameworks, with appreciable differences being found in the two cases. 20 refs

Definition and construction of a first database for assessing the impacts on health and the environment of different strategies for the back end of the fuel cycle

International Nuclear Information System (INIS)

Muller, O.; Ouzounian, G.

1998-01-01

The life cycle assessment framework has been applied to the management of used fuel cycle to determine a general methodology to study the impacts on health and the environment of the back end of the fuel cycle. System definition starts with a definite waste fuel composition and covers all the industrial steps until all elements of the waste are stored. It is recommended to use electricity generation as a functional unit especially for comparing different strategies. In this case, as some parts of the nuclear waste may be recycled to produce electricity, systems have to be expanded to cover both front and back ends of the fuel cycle. A first bibliographical database covering different stages of the nuclear cycle has been constructed and stored with the standard Ecobilan format developed for environmental analysis and management. Data collection includes all steps from mining extraction to ultimate disposal. Together with the constitution of this database several typical strategies for PWR fuels have been assessed. A first list of criteria has been chosen to best represent the impacts of each strategy on both human health of population and workers and the environment. Data gathered for each step are ready to be reused for designing and assessing simulations on alternative nuclear cycles. (author)

The control system for the CMS tracker front-end

CERN Document Server

Drouhin, F; Ljuslin, C; Maazouzi, C; Marchiero, A; Marinelli, N; Paillard, C; Siegrist, P; Tsirou, A L; Verdini, P G; Walsham, P; Zghiche, A

2002-01-01

The CMS Tracker uses complex, programmable embedded electronics for the readout of the Silicon sensors, for the control of the working point of the optical transmitters, for the phase adjustment of the 40 MHz LHC clock and for the monitoring of the voltages, currents and temperatures. In order to establish reliable, noise-free communication with the outside world the control chain has been designed to operate over a ribbon of optical fibers. The optical links, the Front End Controller board that carries their support electronics, the Clocking and Control Unit module receiving the signals over the high-speed link and fanning them out to the front- ends have recently become available. A multi-layered software architecture to handle these devices, and the front-ends, in a way transparent to the end-user, interfaced to an Oracle database for the retrieval of the parameters to be downloaded with the intent of building and operating a small-scale prototype of the control system for the CMS Tracker. The paper descri...

The nuclear fuel cycle back-end: purposes and outlook

International Nuclear Information System (INIS)

Boullis, B.

2010-01-01

The recycling of spent fuels appears as the only way to get a sustainable nuclear energy. Uranium and plutonium recycling technologies are already implemented in France but they require to be upgraded in order to follow the technical evolutions of reactors. The research topics concerning recycling are: -) the adaptation of recycling technologies to higher burn-ups and to the use of Mox fuels, -) to improve the recycling technologies in terms of waste production, -) to prepare the multi-recycling of spent fuels from fast reactors, and -) to go ahead in the recycling policy by separating minor actinides in order to transmute them. (A.C.)

Developing safety in the nuclear fuel cycle

International Nuclear Information System (INIS)

Brown, M.L.

1996-01-01

The nuclear fuel cycle had its origins in the new technology developed in the 1940s and 50s involving novel physical and chemical processes. At the front end of the cycle, mining, milling and fuel fabrication all underwent development, but in general the focus of process development and safety concerns was the reprocessing stage, with radiation, contamination and criticality the chief hazards. Safety research is not over and there is still work to be done in advancing technical knowledge to new generation nuclear fuels such as Mixed Oxide Fuel and in refining knowledge of margins and of potential upset conditions. Some comments are made on potential areas for work. The NUCEF facility will provide many useful data to aid safety analysis and accident prevention. The routine operations in such plants, basically chemical factories, requires industrial safety and in addition the protection of workers against radiation or contamination. The engineering and management measures for this were novel and the early operation of such plants pioneering. Later commissioning and operating experience has improved routine operating safety, leading to a new generation of factories with highly developed worker protection, engineering safeguards and safety management systems. Ventilation of contamination control zones, remote operation and maintenance, and advanced neutron shielding are engineering examples. In safety management, dose control practices, formally controlled operating procedures and safety cases, and audit processes are comparable with, or lead, best industry practice in other hazardous industries. Nonetheless it is still important that the knowledge and experience from operating plants continue to be gathered together to provide a common basis for improvement. The NEA Working Group on Fuel Cycle Safety provides a forum for much of this interchange. Some activities in the Group are described in particular the FINAS incident reporting system. (J.P.N.)

Lower end fitting debris collector and end cap spacer grid

International Nuclear Information System (INIS)

Bryan, W.J.

1990-01-01

This patent describes a nuclear reactor having fuel assemblies including an upper end fitting and spaced nuclear fuel rod spacer grids for supporting and spacing a plurality of elongated nuclear fuel rods. Each includes a hollow active portion of nuclear fuel filled cladding intermediate the rod ends and tapering end cap of solid material with a circumferential groove on the rod end which first encounters reactor coolant flow, a lower end filtering debris collector and end cap spacer grid for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly and creates fuel rod cladding damage

Prototype ALICE front-end card

CERN Multimedia

Maximilien Brice

2004-01-01

This circuit board is a prototype 48-channel front end digitizer card for the ALICE time projection chamber (TPC), which takes electrical signals from the wire sensors in the TPC and shapes the data before converting the analogue signal to digital data. A total of 4356 cards will be required to process the data from the ALICE TPC, the largest of this type of detector in the world.

Applications of liquid phase chromatographies for the analysis of streams arising at the back end of nuclear fuel cycle

International Nuclear Information System (INIS)

Deshingkar, D.S.; Yalmali, Vrunda S.; Wattal, P.K.

2000-06-01

India has opted for a closed fuel cycle comprising of reprocessing and recycling technology. The back end of such nuclear fuel cycle involves the reprocessing of spent nuclear fuels for recovery of plutonium and depleted uranium by Purex technology. Wastes arising from the reprocessing plant are classified as high, intermediate and low level wastes (HLW, ILW, LLW). HLW is mixture of over 50 elements present in different chemical forms. The accurate analyses of dissolver solution and HLW are the most challenging but essential tasks for reprocessing plant operations and also for further development of treatment methods. Inductively coupled plasma - atomic emission spectroscopy and atomic absorption spectroscopy techniques are suitable for analysis of metallic anions. Ion chromatography has proven capability to analyse number of cations or anions at ppm or even ppb level in single run. The report reviews the literature regarding the title subject. To assess the technical feasibility of ion chromatography for waste analysis, a simulated PHWR-HLW analogue was prepared. The PHWR-HLW analogue and ground water samples were analysed on DIONEX-DX 500 and Metrohm IC. Results obtained clearly demonstrated the usefulness of ion chromatography as vital analytical tool. HLW and other process or waste streams arising at the back end of nuclear fuel cycle can be analysed for alkali, alkaline earth, rare earth and transition metal cations and important anions. Use of fraction collector along with ion chromatography can enhance it's sensitivity to few Bq/ml for radioactive samples. (author)

HINS Linac front end focusing system R&D

Energy Technology Data Exchange (ETDEWEB)

Apollinari, G.; Carcagno, R.H.; Dimarco, J.; Huang, Y.; Kashikhin, V.V.; Orris, D.F.; Page, T.M.; Rabehl, R.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab /Argonne

2008-08-01

This report summarizes current status of an R&D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process.

Front end designs for the 7-GeV advanced photon source

International Nuclear Information System (INIS)

Shu, D.; Barraza, J.; Sanchez, T.; Nielsen, R.W.; Collins, J.T.; Kuzay, T.M.

1992-01-01

The conceptual designs for the insertion device (ID) and bending magnet (BM) front ends have been completed for the 7-GeV Advanced Photon Source (APS) under construction at Argonne National Laboratory. These designs satisfy the generic front end functions. However, the high power and high heat fluxes imposed by the X-ray sources of the 7-GeV APS have presented various design engineering challenges for the front end. Consideration of such challenges and their solutions have led to novel and advanced features including modularized systems, enhanced heat transfer concepts in the fixed mask and the photon shutter designs, a radiation safety philosophy based on multiple photon shutters for a fail-safe operation, a sub-micron resolution beam position monitor for beam monitoring and ring feedback information, and minimal beam filtering concepts to deliver maximized beam power and spectra to the experimenters. The criteria and special features of the front end design are discussed in this paper

A digital Front-End and Readout MIcrosystem for calorimetry at LHC

CERN Multimedia

2002-01-01

% RD-16 A Digital Front-End and Readout Microsystem for Calorimetry at LHC \\\\ \\\\Front-end signal processing for calorimetric detectors is essential in order to achieve adequate selectivity in the trigger function of an LHC experiment, with data identification and compaction before readout being required in the harsh, high rate environment of a high luminosity hadron machine. Other crucial considerations are the extremely wide dynamic range and bandwidth requirements, as well as the volume of data to be transferred to following stages of the trigger and readout system. These requirements are best met by an early digitalization of the detector information, followed by integrated digital signal processing and buffering functions covering the trigger latencies.\\\\ \\\\The FERMI (Front-End Readout MIcrosystem) is a digital implementation of the front-end and readout electronic chain for calorimeters. It is based on dynamic range compression, high speed A to D converters, a fully programmable pipeline/digital filter c...

Magnet Misalignment Studies for the Front-end of the Neutrino Factory

CERN Document Server

Prior, G; Stratakis, D; Neuffer, D; Snopok, P; Rogers, C

2013-01-01

In the Neutrino Factory front-end the muon beam coming from the interaction of a high-power (4 MW) proton beam on a mercury jet target is transformed through a buncher, a phase rotator and an ionization cooling channel before entering the downstream acceleration system. The muon front-end channel is densely packed with solenoid magnets, normal conducting radio-frequency cavities and absorber windows for the cooling section. The tolerance to the misalignment of the different components has to be determined in order on one hand to set the limits beyond which the performance of the front-end channel would be degraded; on the other hand to optimize the design and assembly of the front-end cells such that the component alignment can be checked and corrected for where crucial for the performance of the channel. In this paper we show the results of some of the simulations of the frontend channel performance where the magnetic field direction has been altered compared to the baseline.

Industrial integration of the fuel cycle in Argentina

International Nuclear Information System (INIS)

Koll, J.H.; Kittl, J.E.; Parera, C.A.; Coppa, R.C.; Aguirre, E.J.

1977-01-01

The paper describes the power reactor construction programme in Argentina for the period 1976-1985, on the basis of which the nuclear fuel requirements have been determined. Activities connected with the fuel cycle commenced in 1950 in Argentina with the prospection and working of uranium deposits. On the basis of the nuclear power programme described, plans have been drawn up for the establishment of the industrial plants that will be needed to ensure the domestic supply of fuel. The demand for fuel is correlated with the availability of uranium resources and it is shown to be desirable from the technical, economic and industrial point of view to integrate the front end of the fuel cycle, keeping the irradiation aspects and the tail end at the development level. The authors report the progress that has been made in this field and describe current programmes covering prospection, concentrate production, nuclear purification, conversion to uranium dioxide, production of special alloys and fuel element fabrication. (author)

Industrial integration of the fuel cycle in Argentina

International Nuclear Information System (INIS)

Koll, J.H.; Kittl, J.E.; Parera, C.A.; Coppa, R.C.; Aguirre, E.J.

1983-01-01

The power-reactor construction program in Argentina for the period 1976-1985 is described on the basis of which the nuclear-fuel requirements have been determined. Activities connected with the fuel cycle commenced in 1950 in Argentina with the prospection and working of uranium deposits. On the basis of the nuclear power program described, plans have been drawn up for the establishment of the industrial plants that will be needed to ensure the domestic supply of fuel. The demand for fuel is correlated with the availability of uranium resoures and it is shown to be desirable from the technical, economic and industrial point of view to integrate the front end of the fuel cycle, keeping the irradiation aspects and the tail end at the development level. Progress made in this field and current programs covering exploration, concentrate production, nuclear purification, conversion to uranium dioxide, production of special alloys and fuel element fabrication are described

Control and Interlocking System for Bending Magnet Front-end at Indus-2

Science.gov (United States)

Kane, Sanjeev R.; Garg, Chander Kant; Nandedkar, R. V.

2007-01-01

We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ˜ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0.

Control and Interlocking System for Bending Magnet Front-end at Indus-2

International Nuclear Information System (INIS)

Kane, Sanjeev R.; Garg, Chander Kant; Nandedkar, R. V.

2007-01-01

We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ∼ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0

Nuclear fuel cycle under progressing preparation of its systemisation

International Nuclear Information System (INIS)

Anon.

2001-01-01

Trends of nuclear development in Japan show more remarkable advancements in 2000, such as new addition of nuclear power plant, nuclear fuel cycling business, and so on. Based on an instruction of the criticality accident in JCO formed on September, 1999, government made efforts on revision of the law on regulation of nuclear reactor and so forth and establishment of a law on protection of nuclear accident as sooner, to enforce nuclear safety management and nuclear accident protective countermeasure. On the other hand, the nuclear industry field develops some new actions such as establishment of Nuclear Safety Network (NSnet)', mutual evaluation of nuclear-relative works (pier review), and so forth. And, on the high level radioactive wastes disposal of the most important subject remained in nuclear development, the Nuclear Waste Management Organization of Japan' of its main business body was established on October, 1999 together with establishment of the new law, to begin a business for embodiment of the last disposal aiming at 2030s to 2040s. On the same October, the Japan Nuclear Fuel Limited. concluded a safety agreement on premise of full-dress transportation of the used fuels to the Rokkasho Reprocessing Plant in Aomori prefecture with local government, to begin their transportation from every electric company since its year end. Here were described on development of the nuclear fuel cycling business in Japan, establishment of nuclear fuel cycling, disposal on the high level radioactive wastes, R and D on geological disposal of the high level radioactive wastes, establishment on cycle back-end of nuclear fuels, and full-dressing of nuclear fuel cycling. (G.K.)

Nuclear

International Nuclear Information System (INIS)

2014-01-01

This document proposes a presentation and discussion of the main notions, issues, principles, or characteristics related to nuclear energy: radioactivity (presence in the environment, explanation, measurement, periods and activities, low doses, applications), fuel cycle (front end, mining and ore concentration, refining and conversion, fuel fabrication, in the reactor, back end with reprocessing and recycling, transport), the future of the thorium-based fuel cycle (motivations, benefits and drawbacks), nuclear reactors (principles of fission reactors, reactor types, PWR reactors, BWR, heavy-water reactor, high temperature reactor of HTR, future reactors), nuclear wastes (classification, packaging and storage, legal aspects, vitrification, choice of a deep storage option, quantities and costs, foreign practices), radioactive releases of nuclear installations (main released radio-elements, radioactive releases by nuclear reactors and by La Hague plant, gaseous and liquid effluents, impact of releases, regulation), the OSPAR Convention, management and safety of nuclear activities (from control to quality insurance, to quality management and to sustainable development), national safety bodies (mission, means, organisation and activities of ASN, IRSN, HCTISN), international bodies, nuclear and medicine (applications of radioactivity, medical imagery, radiotherapy, doses in nuclear medicine, implementation, the accident in Epinal), nuclear and R and D (past R and D programmes and expenses, main actors in France and present funding, main R and D axis, international cooperation)

Measurement of Design Process Front-End – Radical Innovation Approach

DEFF Research Database (Denmark)

Berg, Pekka; Pihlajamaa, Jussi; Hansen, Poul H. Kyvsgård

2014-01-01

The overall structure and the main characteristics of the future product are all decided in the front-end phase, which then strongly affects subsequent new product development activities. Recent studies indicate that these early front-end activities represent the most troublesome phase...... of the innovation process, and at the same time one of the greatest opportunities to improve the overall innovation capability of a company. In this paper dealing with the criteria we concentrate only for the objectives viewpoint and leave the attributes discussion to the future research. Two most crucial questions...... the innovation activities front end contains five assessment viewpoints as follows; input, process, output (including impacts), social environment and structural environment. Based on the results from our first managerial implications in three Finnish manufacturing companies we argue, that the developed model...

Radiation exposure control in back end of nuclear fuel cycle facilities

International Nuclear Information System (INIS)

Pendharkar, K.A.

2003-01-01

Fuel Reprocessing Plant and Waste Immobilization Plant for management of high level liquid waste, generated during reprocessing, form part of the back end of Nuclear Fuel Cycle. Both the plants handle annually several million curie of fission products in easily dispersible form. There is potential for significant external exposure and internal contamination to plant workers during plant operations, associated maintenance works and also during outages for carrying out repairs/modifications inside cells where process equipment handling/storing radioactive materials are installed. In view of handling of fissile material (Pu) in a reprocessing plant, special attention has to be paid to ensure that a condition for self sustaining nuclear fission chain reaction (criticality) does not arise even under foreseeable maloperation conditions. The reprocessing plant and Waste Immobilization plant have several engineered safety features such as shielding, ventilation, containment, remote operation etc. These features aim at reducing exposure to plant personnel and keeping the release of radioactive materials to environment below the limits specified in Technical Specifications of the plant. Execution of a comprehensive radiological surveillance programme which includes area monitoring, personal monitoring, effluent monitoring and investigative surveys in connection with safety related unusual occurrences, plays very important role in ensuring radiation safety of plant personnel and the environment. This together with training in radiation safety to plant workers helps reduce 'radiation phobia' in some workers. The paper describes radiological safety considerations and radiological surveillance programme (giving specific examples where required) that is being implemented in reprocessing plants and Waste Immobilization Plants in India. (author)

Optimized capture section for a muon accelerator front end

Directory of Open Access Journals (Sweden)

Hisham Kamal Sayed

2014-07-01

Full Text Available In a muon accelerator complex, a target is bombarded by a multi-MW proton beam to produce pions, which decay into the muons which are thereafter bunched, cooled, and accelerated. The front end of the complex captures those pions, then manipulates their phase space, and that of the muons into which they decay, to maximize the number of muons within the acceptance of the downstream systems. The secondary pion beam produced at the target is captured by a high field target solenoid that tapers down to a constant field throughout the rest of the front end. In this study we enhance the useful muon flux by introducing a new design of the longitudinal profile of the solenoid field at, and downstream of, the target. We find that the useful muon flux exiting the front end is larger when the field at the target is higher, the distance over which the field tapers down is shorter, and the field at the end of the taper is higher. We describe how the solenoid field profile impacts the transverse and longitudinal phase space of the beam and thereby leads to these dependencies.

Fuel assembly insertion system

International Nuclear Information System (INIS)

Barkhurst, D.J.

1987-01-01

This patent describes a nuclear reactor facility having fuel bundles: a system for the insertion of a fuel bundle into a position where vertically arranged fuel bundles surround and are adjacent the system comprising, in combination, separate and individual centering devices secured to and disposed on top of each fuel bundle adjacent the position. Each such centering device has a generally box-like cap configuration on the upper end of each fuel bundle and includes: a top wall; first and second side walls, each secured along and upper edge to the top wall; a rear plate attached along opposite vertical edges to the first and second side walls; a front inclined wall joined along an upper edge to the top to the wall and attached along opposite vertical edges first and second side walls; pad means secured to the lower edge of the first and second side walls, the front inclined wall and the rear plate for mounting each centering device on top of an associated fuel bundle; pin means carried by at least two of the pad means engageable with an associated aperature for locating and laterally fixing each centering device on top of its respective fuel bundle. Each front inclined wall of each of the centering devices is orientated on top of its respective fuel bundle to slope upwardly and away from the position where upon downward insertion of a fuel bundle any contact between the lower end of the fuel bundle inserted with a front inclined wall of a centering device will laterally deflect the fuel bundle. Each centering device further includes a central socket means secured to the top wall, and an elongated handling pole pivotally attached to the socket

The ALICE TPC front end electronics

CERN Document Server

Musa, L; Bialas, N; Bramm, R; Campagnolo, R; Engster, Claude; Formenti, F; Bonnes, U; Esteve-Bosch, R; Frankenfeld, Ulrich; Glässel, P; Gonzales, C; Gustafsson, Hans Åke; Jiménez, A; Junique, A; Lien, J; Lindenstruth, V; Mota, B; Braun-Munzinger, P; Oeschler, H; Österman, L; Renfordt, R E; Ruschmann, G; Röhrich, D; Schmidt, H R; Stachel, J; Soltveit, A K; Ullaland, K

2004-01-01

In this paper we present the front end electronics for the time projection chamber (TPC) of the ALICE experiment. The system, which consists of about 570000 channels, is based on two basic units: (a) an analogue ASIC (PASA) that incorporates the shaping-amplifier circuits for 16 channels; (b) a mixed-signal ASIC (ALTRO) that integrates 16 channels, each consisting of a 10-bit 25-MSPS ADC, the baseline subtraction, tail cancellation filter, zero suppression and multi-event buffer. The complete readout chain is contained in front end cards (FEC), with 128 channels each, connected to the detector by means of capton cables. A number of FECs (up to 25) are controlled by a readout control unit (RCU), which interfaces the FECs to the data acquisition (DAQ), the trigger, and the detector control system (DCS) . A function of the final electronics (1024 channels) has been characterized in a test that incorporates a prototype of the ALICE TPC as well as many other components of the final set-up. The tests show that the ...

Lanthanide - actinide separation: a challenge in the back end of nuclear fuel cycle

International Nuclear Information System (INIS)

Mohapatra, P.K.

2015-01-01

Due to their similar size and chemical state, separation of trivalent lanthanide and actinide ions has always been a challenging topic of research. Of late, the growing concern for the radioactive waste management in the back end of the nuclear fuel cycle has led to the possibility of transmuting the long-lived transuranides in high flux reactors. This necessitates the development of processes for the separation of lanthanides and actinides in acidic/low pH media. In view of the high absorption cross section of few lanthanides, their presence in relatively large proportion (10-100 times) impedes the transmutation process. Processes such as the TRAMEX and TALSPEAK have been used for the separation of lanthanides from trivalent actinides. Of late soft donor ligands containing S and N donor atoms have been used for the selective extraction of trivalent actinide ions. The commercially available S-donor compound, CYANEX 301 (bis(2,4,4-trimethylpentyl) dithiophosphinic acid) has been used to yield separation factor (S.F.) values in the excess of 6000. Synergistic extraction with N-donor ligands such as 2,2'-bipyridyl and 1,10-phenanthroline have yielded S.F. values close to 40,000. N-donor ligands such as BTP (bis-triazinylpyridine), BTBP (bis-triazinylbipyridyl) and BTPhen (bis-triazinyl-phenanthroline) have been particularly effective from relatively acidic feed conditions. The present lecture will give a brief outline of the separation processes and experimental results of studies carried out using various S and N donor ligands. Use of room temperature ionic liquids for more favorable separations will be highlighted. Liquid membrane separation results for application to back end nuclear fuel cycle will also be discussed. (author)

Nuclear Physics on the Light Front

OpenAIRE

Miller, Gerald A.

1999-01-01

High energy scattering experiments involving nuclei are typically analyzed in terms of light front variables. The desire to provide realistic, relativistic wave functions expressed in terms of these variables led me to try to use light front dynamics to compute nuclear wave functions. The progress is summarized here.

Current concept of the nuclear fuel cycle in the Czech Republic

International Nuclear Information System (INIS)

Priman, V.; Vesely, P.; Sedina, M.

2001-01-01

The article provides an overview of the major activities within the nuclear fuel cycle as practised by the Czech utility CEZ, a. s. Efforts in the fuel cycle practice are focused on the implementation of standard business principles with CEZ's contractual suppliers; application of new legislation and international design standards; and on achieving a higher technical standard of nuclear fuel and its better overall utilisation by nuclear power plants. Business activities in the procurement of nuclear materials and their diversification are discussed. The last part of the article, which is devoted to the fuel cycle back-end, describes the adopted strategy of extended spent fuel storage associated with a postponement of the final disposal. The basic principles of the CEZ's fuel cycle back-end strategy are also summarised. (author)

Further development and data basis for safety and accident analyses of nuclear front end and back end facilities and actualization and revision of calculation methods for nuclear safety analyses. Final report; Weiterentwicklung von Methoden und Datengrundlagen zu Sicherheits- und Stoerfallanalysen fuer Anlagen der nuklearen Ver- und Entsorgung sowie Aktualisierung und Ueberpruefung von Rechenmethoden zu nuklearen Sicherheitsanalysen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Kilger, Robert; Peters, Elisabeth; Sommer, Fabian; Moser, Eberhard-Franz; Kessen, Sven; Stuke, Maik

2016-07-15

This report briefly describes the activities carried out under the project 3613R03350 on the GRS ''Handbook on Accident Analysis for Nuclear Front and Back End Facilities'', and in detail the continuing work on the revision and updating of the GRS ''Handbook on Criticality'', which here focused on fissile systems with plutonium and {sup 233}U. The in previous projects started and ongoing literature study on innovative fuel concepts is continued. Also described are the review and qualification of computational methods by research and active benchmark participation, and the results of tracking the state of science and technology in the field of computational methods for criticality safety analysis. Special in-depth analyzes of selected criticality-relevant occurrences in the past are also documented.

Annotated Bibliography for Drying Nuclear Fuel

Energy Technology Data Exchange (ETDEWEB)

Rebecca E. Smith

2011-09-01

Internationally, the nuclear industry is represented by both commercial utilities and research institutions. Over the past two decades many of these entities have had to relocate inventories of spent nuclear fuel from underwater storage to dry storage. These efforts were primarily prompted by two factors: insufficient storage capacity (potentially precipitated by an open-ended nuclear fuel cycle) or deteriorating quality of existing underwater facilities. The intent of developing this bibliography is to assess what issues associated with fuel drying have been identified, to consider where concerns have been satisfactorily addressed, and to recommend where additional research would offer the most value to the commercial industry and the U. S. Department of Energy.

Wide-band low-noise distributed front-end for multi-gigabit CPFSK receivers

DEFF Research Database (Denmark)

Petersen, Anders Kongstad; Ebskamp, F; Pedersen, Rune Johan Skullerud

1994-01-01

In this paper a distributed optical front-end amplifier for a coherent optical CPFSK receiver is presented. The measured average input noise current density is 20 pA/√(Hz) in a 3-13 GHz bandwidth. This is the lowest value reported for a distributed optical front-end in this frequency range....... The front-end is tested in a system set-up at a bit rate of 2.5 Gbit/s and a receiver sensitivity of -41.5 dBm is achieved at a 10-9 bit error rate...

Rack for nuclear fuel elements

International Nuclear Information System (INIS)

Rubinstein, H.J.; Gordon, C.B.; Robison, A.; Clark, P.M.

1977-01-01

Disclosed is a rack for storing spent nuclear fuel elements in which a plurality of aligned rows of upright enclosures of generally square cross-sectional areas contain vertically disposed spent fuel elements. Each fuel element is supported at the lower end thereof by a respective support that rests on the floor of the spent fuel pool for a nuclear power plant. An open rack frame is employed as an upright support for the enclosures containing the spent fuel elements. Legs at the lower corners of the frame rest on the floor of the pool to support the frame. In one exemplary embodiment, the support for the fuel element is in the form of a base on which a fuel element rests and the base is supported by legs. In another exemplary embodiment, each fuel element is supported on the pool floor by a self-adjusting support in the form of a base on which a fuel element rests and the base rests on a ball or swivel joint for self-alignment. The lower four corners of the frame are supported by legs adjustable in height for leveling the frame. Each adjustable frame leg is in the form of a base resting on the pool floor and the base supports a threaded post. The threaded post adjustably engages a threaded column on which rests the lower end of the frame. 16 claims, 14 figures

Design of analog front-ends for the RD53 demonstrator chip

CERN Document Server

Gaioni, L; Nodari, B; Manghisoni, M; Re, V; Traversi, G; Barbero, M B; Fougeron, D; Gensolen, F; Godiot, S; Menouni, M; Pangaud, P; Rozanov, A; Wang, A; Bomben, M; Calderini, G; Crescioli, F; Le Dortz, O; Marchiori, G; Dzahini, D; Rarbi, F E; Gaglione, R; Gonella, L; Hemperek, T; Huegging, F; Karagounis, M; Kishishita, T; Krueger, H; Rymaszewski, P; Wermes, N; Ciciriello, F; Corsi, F; Marzocca, C; De Robertis, G; Loddo, F; Licciulli, F; Andreazza, A; Liberali, V; Shojaii, S; Stabile, A; Bagatin, M; Bisello, D; Mattiazzo, S; Ding, L; Gerardin, S; Giubilato, P; Neviani, A; Paccagnella, A; Vogrig, D; Wyss, J; Bacchetta, N; Della Casa, G; Demaria, N; Mazza, G; Rivetti, A; Da Rocha Rolo, M D; Comotti, D; Ratti, L; Vacchi, C; Beccherle, R; Bellazzini, R; Magazzu, G; Minuti, M; Morsani, F; Palla, F; Poulios, S; Fanucci, L; Rizzi, A; Saponara, S; Androsov, K; Bilei, G M; Menichelli, M; Conti, E; Marconi, S; Passeri, D; Placidi, P; Monteil, E; Pacher, L; Paternò, A; Gajanana, D; Gromov, V; Hessey, N; Kluit, R; Zivkovic, V; Havranek, M; Janoska, Z; Marcisovsky, M; Neue, G; Tomasek, L; Kafka, V; Sicho, P; Vrba, V; Vila, I; Lopez-Morillo, E; Aguirre, M A; Palomo, F R; Muñoz, F; Abbaneo, D; Christiansen, J; Dannheim, D; Dobos, D; Linssen, L; Pernegger, H; Valerio, P; Alipour Tehrani, N; Bell, S; Prydderch, M L; Thomas, S; Christian, D C; Fahim, F; Hoff, J; Lipton, R; Liu, T; Zimmerman, T; Garcia-Sciveres, M; Gnani, D; Mekkaoui, A; Gorelov, I; Hoeferkamp, M; Seidel, S; Toms, K; De Witt, J N; Grillo, A

2017-01-01

The RD53 collaboration is developing a large scale pixel front-end chip, which will be a tool to evaluate the performance of 65 nm CMOS technology in view of its application to the readout of the innermost detector layers of ATLAS and CMS at the HL-LHC. Experimental results of the characterization of small prototypes will be discussed in the frame of the design work that is currently leading to the development of the large scale demonstrator chip RD53A to be submitted in early 2017. The paper is focused on the analog processors developed in the framework of the RD53 collaboration, including three time over threshold front-ends, designed by INFN Torino and Pavia, University of Bergamo and LBNL and a zero dead time front-end based on flash ADC designed by a joint collaboration between the Fermilab and INFN. The paper will also discuss the radiation tolerance features of the front-end channels, which were exposed to up to 800 Mrad of total ionizing dose to reproduce the system operation in the actual experiment.

Analog front end circuit design of CSNS beam loss monitor system

International Nuclear Information System (INIS)

Xiao Shuai; Guo Xian; Tian Jianmin; Zeng Lei; Xu Taoguang; Fu Shinian

2013-01-01

The China Spallation Neutron Source (CSNS) beam loss monitor system uses gas ionization chamber to detect beam losses. The output signals from ionization chamber need to be processed in the analog front end circuit, which has been designed and developed independently. The way of transimpedance amplifier was used to achieve current-voltage (I-V) conversion measurement of signal with low repetition rate, low duty cycle and low amplitude. The analog front end circuit also realized rapid response to the larger beam loss in order to protect the safe operation of the accelerator equipment. The testing results show that the analog front end circuit meets the requirements of beam loss monitor system. (authors)

A THEORETICAL MODEL OF SUPPORTING OPEN SOURCE FRONT END INNOVATION THROUGH IDEA MANAGEMENT

DEFF Research Database (Denmark)

Aagaard, Annabeth

2013-01-01

to overcome these various challenges companies are looking for new models to support FEI. This theoretical paper explores in what way idea management may be applied as a tool in facilitation of front end innovation and how this facilitation may be captured in a conceptual model. First, I show through...... a literature study, how idea management and front end innovation are related and how they may support each other. Secondly, I present a theoretical model of how idea management may be applied in support of the open source front end of new product innovations. Thirdly, I present different venues of further...... exploration of active facilitation of open source front end innovation through idea management....

Nuclear-fuel-cycle costs. Consolidated Fuel-Reprocessing Program

International Nuclear Information System (INIS)

Burch, W.D.; Haire, M.J.; Rainey, R.H.

1981-01-01

The costs for the back-end of the nuclear fuel cycle, which were developed as part of the Nonproliferation Alternative Systems Assessment Program (NASAP), are presented. Total fuel-cycle costs are given for the pressurized-water reactor once-through and fuel-recycle systems, and for the liquid-metal fast-breeder-reactor system. These calculations show that fuel-cycle costs are a small part of the total power costs. For breeder reactors, fuel-cycle costs are about half that of the present once-through system. The total power cost of the breeder-reactor system is greater than that of light-water reactor at today's prices for uranium and enrichment

Scientific research on the back-end of the fuel cycle for the 21. century

International Nuclear Information System (INIS)

2000-01-01

The aim of the Atalante-2000 conference is to present the major research axis concerning the nuclear fuel cycle back-end. The different topics are: - Present options concerning fuel cycle back-end; - Reprocessing of spent fuel; - Advanced separation for transmutation; - Processing and packaging of radioactive wastes; - Design and fabrication of targets for transmutation; and - Conversion of military plutonium into MOX fuels

Greneche, Dominique (Nuclear Consulting (FR))

International Nuclear Information System (INIS)

Thorium-based fuel cycle

2013-01-01

In this engineering-oriented publication, the author first gives reviews the motivations for the use of thorium-based fuel cycle: comparison with uranium-based fuel cycle, thorium and uranium characteristics, thorium physical properties, current use of thorium (out of nuclear industry), and thorium abundance and natural resources. He recalls the history of the development of thorium-based cycle: experimental use of thorium in reactor, motivations and obstacles during the development of thorium-based cycle, current status of this development. Then, the author proposes a detailed presentation of technical characteristics of the thorium-based fuel cycle, while outlining the associated industrial challenges: front-end of fuel cycle (mining, concentration, fuel fabrication), characteristics and behaviour of thorium-based fuels in reactors (general neutronics properties, fuel behaviour under irradiation, management of nuclear materials, plutonium consumption), and back-end of the fuel cycle (processing, U-233 recycling, waste warehousing and storage). The last part addresses non-proliferation and economic issues related to the development of thorium-based fuel cycle

World Nuclear Association position statement: Safe management of nuclear waste and used nuclear fuel

International Nuclear Information System (INIS)

Saint-Pierre, Sylvain

2006-01-01

This WNA Position Statement summarises the worldwide nuclear industry's record, progress and plans in safely managing nuclear waste and used nuclear fuel. The global industry's safe waste management practices cover the entire nuclear fuel-cycle, from the mining of uranium to the long-term disposal of end products from nuclear power reactors. The Statement's aim is to provide, in clear and accurate terms, the nuclear industry's 'story' on a crucially important subject often clouded by misinformation. Inevitably, each country and each company employs a management strategy appropriate to a specific national and technical context. This Position Statement reflects a confident industry consensus that a common dedication to sound practices throughout the nuclear industry worldwide is continuing to enhance an already robust global record of safe management of nuclear waste and used nuclear fuel. This text focuses solely on modern civil programmes of nuclear-electricity generation. It does not deal with the substantial quantities of waste from military or early civil nuclear programmes. These wastes fall into the category of 'legacy activities' and are generally accepted as a responsibility of national governments. The clean-up of wastes resulting from 'legacy activities' should not be confused with the limited volume of end products that are routinely produced and safely managed by today's nuclear energy industry. On the significant subject of 'Decommissioning of Nuclear Facilities', which is integral to modern civil nuclear power programmes, the WNA will offer a separate Position Statement covering the industry's safe management of nuclear waste in this context. The paper's conclusion is that the safe management of nuclear waste and used nuclear fuel is a widespread, well-demonstrated reality. This strong safety record reflects a high degree of nuclear industry expertise and of industry responsibility toward the well-being of current and future generations. Accumulating

Integrated X-band FMCW front-end in SiGe BiCMOS

NARCIS (Netherlands)

Suijker, Erwin; de Boer, Lex; Visser, Guido; van Dijk, Raymond; Poschmann, Michael; van Vliet, Frank Edward

2010-01-01

An integrated X-band FMCW front-end is reported. The front-end unites the core functionality of an FMCW transmitter and receiver in a 0.25 μm SiGe BiCMOS process. The chip integrates a PLL for the carrier generation, and single-side band and image-reject mixers for up- and down-conversion of the

CEA nuclear energy Directorate - Activity report 2012

International Nuclear Information System (INIS)

2013-01-01

After an overview of the activities of the Directorate at the international level, of its scientific activities, and of the consideration given to quality, and a presentation of the transverse program on advanced materials, this report proposes presentations of activities in different domains: future nuclear industrial systems (reactors of 4. generation, back-end of the future cycle, sustainable management of nuclear materials, fundamental scientific and technological research), optimization of the present industrial nuclear activity (reactors of 2. and 3. generation, front-end and back-end of the fuel cycle), the main tools for nuclear development (numerical simulation, the Jules Horowitz reactor), valorisation, economic support of Haute-Marne and Meuse territories (the Syndiese project), nuclear dismantling and decontamination (dismantling projects, projects and works in Fontenay-aux-Roses, Grenoble and Saclay, waste and material flow management, nuclear service facilities, transports). It also presents the activities of some specific CEA centres like Marcoule (R and D in fuel cycle), Cadarache (future energies) and Saclay (nuclear sciences and simulation of reactors and fuel cycle)

A present status for dry storage of spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Bang, K. S.; Lee, J. C.; Park, H. Y.; Seo, K. S

2003-04-01

National policy for management of a spent nuclear fuel does not establish in Korea yet. A storage capacity of a storage pool that is to store the spent nuclear fuel will be exceeded an amount of accumulation from the first Woljin nuclear power plant in 2007. Therefore it is necessary that dry storage facility is secured to store safely the spent nuclear fuel on site of the nuclear power plant until national policy for a back-end spent nuclear fuel cycle is established. In order to store safely spent nuclear fuel, it is important that the present status and technology on dry storage of spent nuclear fuel is looked over. Therefore, the present status on dry storage of spent nuclear fuel was analyzed so as to develop dry storage system and choose a proper dry storage method domestic.

Nuclear reactor spent fuel storage rack

International Nuclear Information System (INIS)

Machado, O.J.; Flynn, W.M.; Flanders, H.E. Jr.; Booker, L.W.

1989-01-01

A fuel rack is described for use in storing nuclear fuel assemblies in a nuclear fuel storage pool having a floor on which an upwardly projecting stud is mounted; the fuel rack comprising: a base structure at the lower end of the fuel rack including base-plate means having flow openings therein, the base-plate means supporting a first network of interlaced beams which form a multiplicity of polygonal openings; a second network of interlaced beams forming polygonal openings positioned in spaced vertical alignment with corresponding polygonal openings in the first network of beams; a plurality of cells, each cell having sides bounded by inner and outer surfaces and being of a size and configuration designed to hold therein a fuel assembly, each cell positioned in a corresponding pair of the aligned polygonal openings, each cell being open at both ends with a guiding funnel at the upper end, and the cells being positioned over the flow openings in the base-plate to permit flow of coolant through the cells; spaced, outwardly directed, projections on the outer surfaces of the sides of the cells near the tops and bottoms of the sides thereof, each cell being sized to be received within a corresponding of the pair of aligned polygonal openings in which the cells are respectively positioned; and means fixedly securing the projections to the beams in the first and second networks of beams thereby to provide a substantially rigid fuel rack of modular design

The use of nuclear data in the field of nuclear fuel recycling

Directory of Open Access Journals (Sweden)

Martin Julie-Fiona

2017-01-01

Full Text Available AREVA NC La Hague facility is the first step of the nuclear fuel recycling process implemented in France. The processing of the used fuel is governed by high standards of criticality-safety, and strong expectations on the quality of end-products. From the received used fuel assemblies, the plutonium and the uranium are extracted for further energy production purposes within the years following the reprocessing. Furthermore, the ultimate waste – fission products and minor actinides on the one hand, and hulls and end-pieces on the other hand – is adequately packaged for long term disposal. The used fuel is therefore separated into very different materials, and time scales which come into account may be longer than in some other nuclear fields of activity. Given the variety of the handled nuclear materials, as well as the time scales at stake, the importance given to some radionuclides, and hence to the associated nuclear data, can also be specific to the AREVA NC La Hague plant. A study has thus been led to identify a list of the most important radionuclides for the AREVA NC La Hague plant applications, relying on the running constraints of the facility, and the end-products expectations. The activities at the AREVA NC La Hague plant are presented, and the methodology to extract the most important radionuclides for the reprocessing process is detailed.

The use of nuclear data in the field of nuclear fuel recycling

Science.gov (United States)

Martin, Julie-Fiona; Launay, Agnès; Grassi, Gabriele; Binet, Christophe; Lelandais, Jacques; Lecampion, Erick

2017-09-01

AREVA NC La Hague facility is the first step of the nuclear fuel recycling process implemented in France. The processing of the used fuel is governed by high standards of criticality-safety, and strong expectations on the quality of end-products. From the received used fuel assemblies, the plutonium and the uranium are extracted for further energy production purposes within the years following the reprocessing. Furthermore, the ultimate waste - fission products and minor actinides on the one hand, and hulls and end-pieces on the other hand - is adequately packaged for long term disposal. The used fuel is therefore separated into very different materials, and time scales which come into account may be longer than in some other nuclear fields of activity. Given the variety of the handled nuclear materials, as well as the time scales at stake, the importance given to some radionuclides, and hence to the associated nuclear data, can also be specific to the AREVA NC La Hague plant. A study has thus been led to identify a list of the most important radionuclides for the AREVA NC La Hague plant applications, relying on the running constraints of the facility, and the end-products expectations. The activities at the AREVA NC La Hague plant are presented, and the methodology to extract the most important radionuclides for the reprocessing process is detailed.

Investigation on Nd:YAG laser weldability of zircaloy-4 end cap closure for nuclear fuel elements

International Nuclear Information System (INIS)

Kim, Soo Sung; Lee, Chul Yung; Yang, Myung Seung

2001-01-01

Various welding processes are now available for end cap closure of nuclear fuel element such as TIG(Tungsten Inert Gas) welding, magnetic resistance welding and laser welding. Even though the resistance and TIG welding processes are widely used for manufacturing commercial fuel elements, they can not be recommended for the remote seal welding of a fuel element at a hot cell facility due to the complexity of electrode alignment, difficulty in the replacement of parts in the remote manner and a large heat input for a thin sheath. Therefore, the Nd:YAG laser system using optical fiber transmission was selected for Zircaloy-4 end cap welding inside hot cell. The laser welding apparatus was developed using a pulsed Nd:YAG laser of 500 watt average power with optical fiber transmission. The weldability of laser welding was satisfactory with respect to the microstructures and mechanical properties comparing with TIG and resistance welding. The optimum operation processes of laser welding and the optical fiber transmission system for hot cell operation in a remote manner have been developed. The effects of irradiation on the properties of the laser apparatus were also being studied

Nuclear fuel grid outer strap

International Nuclear Information System (INIS)

Duncan, R.; Craver, J.E.

1989-01-01

This patent describes a nuclear reactor fuel assembly grid. It comprises a first outer grip strap segment end. The first end having a first tab arranged in substantially the same plane as the plane defined by the first end; a second outer grip strap end. The second end having a second slot arranged in substantially the same plane as the plane defined by the second end, with the tab being substantially disposed in the slot, defining a socket therebetween; and a fort tine interposed substantially perpendicularly in the socket

Feasibility and desirability of employing the thorium fuel cycle for power generation - 254

International Nuclear Information System (INIS)

Sehgal, B.R.

2010-01-01

Thorium fuel cycle for nuclear power generation has been considered since the very start of the nuclear power era. In spite of a very large amount of research, experimentation, pilot scale and prototypic scale installations, the thorium fuel was not adopted for large scale power generation [1,2]. This paper reviews the developments over the years on the front and the back-end of the thorium fuel cycle and describes the pros and cons of employing the thorium fuel cycle for large generation of nuclear power. It examines the feasibility and desirability of employing the thorium fuel cycle in concert with the uranium fuel cycle for power generation. (authors)

Reconstitutable fuel assembly for a nuclear reactor

International Nuclear Information System (INIS)

Ferlan, S.J.; Kmonk, S.; Schallenberger, J.M.

1982-01-01

A reconstitutable fuel assembly for a nuclear reactor which includes a mechanical, rather than metallurgical, arrangement for connecting control rod guide thimbles to the top and bottom nozzles of a fuel assembly. Multiple sleeves enclosing control rod guide thimbles interconnect the top nozzle to the fuel assembly upper grid. Each sleeve is secured to the top nozzle by retaining rings disposed on opposite sides of the nozzle. Similar sleeves enclose the lower end of control rod guide thimbles and interconnect the bottom nozzle with the lowermost grid on the assembly. An end plug fitted in the bottom end of each sleeve extends through the bottom nozzle and is secured thereto by a retaining ring. Should it be necessary to remove a fuel rod from the assembly, the retaining rings in either the top or bottom nozzles may be removed to release the nozzle from the control rod guide thimbles and thus expose either the top or bottom ends of the fuel rods to fuel rod removing mechanisms

Modelling the redox front movement in a KBS-3 nuclear waste repository

International Nuclear Information System (INIS)

Romero, L.; Moreno, L.; Neretnieks, I.

1993-05-01

In a KBS-3 repository for spent nuclear fuel, radiolysis can occur if canisters are breached and water comes into contact with the fuel. The oxidants produced by radiolysis may migrate into the clay surrounding the canister and change the redox conditions from reducing to oxidizing. If much oxidants are produced, they can migrate to the water flowing in the fractures in the rock. Some of the oxidants also may oxidize the uranium and other nuclides in the fuel and make them more soluble. The nuclides will then migrate out in a higher oxidation state and may precipitate at the redox front. Calculations were done for a production of 144 moles of oxidants in one million years. A higher and a much lower production were also considered. It was assumed that the canister is either totally or locally corroded. The results show that, for the most probable production rate, a large fraction of oxidants would be consumed in the clay. If the corrosion is local and there is a fracture opposite the damage, the amount of oxidant transported into the fracture would be significant. Here the advance of the redox front in the fracture would be some tens of metres. For the lowest production rate, the oxidants never reach the fractures in the rock. Only with improbably high production rates could the tips of the redox front move very long distances, in isolated channels that are not part of a network

MUON POLARIZATION EFFECTS IN THE FRONT END OF THE NEUTRINO FACTORY

International Nuclear Information System (INIS)

FERNOW, R.C.; GALLARDO, J.C.; FUKUI, Y.

2000-01-01

The authors summarize the methods used for simulation of polarization effects in the front end of a possible neutrino factory. They first discuss the helicity of muons in the pion decay process. They find that, neglecting acceptance considerations, the average helicity asymptotically approaches a magnitude of 0.185 at large pion momenta. Next they describe the methods used for tracking the spin through the complicated electromagnetic field configurations in the front end of the neutrino factory, including rf phase rotation and ionization cooling channels. Various depolarizing effects in matter are then considered, including multiple Coulomb scattering and elastic scattering from atomic electrons. Finally, they include all these effects in a simulation of a 480 m long, double phase rotation front end scenario

The Canadian nuclear fuel waste management program

International Nuclear Information System (INIS)

Dixon, R.S.

1984-12-01

The Canadian Nuclear Fuel Waste Management Program involves research into the storage and transportation of used nuclear fuel, immobilization of fuel waste, and deep geological disposal of the immobilized waste. The program is now in the fourth year of a ten-year generic research and development phase. The objective of this phase of the program is to assess the safety and environmental aspects of the deep underground disposal of immobilized fuel waste in plutonic rock. The objectives of the research for each component of the program and the progress made to the end of 1983 are described in this report

Redesigned front end for the upgrade at CHESS

International Nuclear Information System (INIS)

Headrick, R.L.; Smolenski, K.W.

1996-01-01

We will report on beamline front-end upgrades for the 24-pole wiggler beamlines at CHESS. A new design for primary x-ray beamstops based on a tapered, water-cooled copper block has been implemented and installed in the CHESS F beamline. The design uses a horizontally tapered open-quote open-quote V close-quote close-quote shape to reduce the power density on the internal surfaces and internal water channels in the block to provide efficient water cooling. Upstream of the beam stops, we have installed a new photoelectron style beam position monitor with separate monitoring of the wiggler and dipole vertical beam positions and with micron-level sensitivity. The monitor close-quote s internal surfaces are designed to absorb the full x-ray power in case of beam missteering, and the uncooled photoelectron collecting plates are not visible to the x-ray beam. A graphite prefilter has been installed to protect the beryllium windows that separate the front end from the x-ray optics downstream. The redesigned front end is required by the upgrade of the Cornell storage ring, now in progress, which will allow stored electron and positron currents of 300 mA by 1996, and 500 mA by 1998. At 500 mA, the wiggler power output will be over 32 kW. copyright 1996 American Institute of Physics

Internal attachment of laser beam welded stainless steel sheathed thermocouples into stainless steel upper end caps in nuclear fuel rods for the LOFT Reactor

International Nuclear Information System (INIS)

Welty, R.K.; Reid, R.D.

1980-01-01

The Exxon Nuclear Company, Inc., acting as a subcontractor to EG and G Idaho Inc., Idaho National Engineering Laboratory, Idaho Falls, Idaho, conducted a laser beam welding study to attach internal stainless steel thermocouples into stainless steel upper end caps in nuclear fuel rods. The objective of this study was to determine the feasibility of laser welding a single 0.063 inch diameter stainless steel (304) sheathed thermocouple into a stainless steel (316) upper end cap for nuclear fuel rods. A laser beam was selected because of the extremely high energy input in unit volume that can be achieved allowing local fusion of a small area irrespective of the difference in material thickness to be joined. A special weld fixture was designed and fabricated to hold the end cap and the thermocouple with angular and rotational adjustment under the laser beam. A commercial pulsed laser and energy control system was used to make the welds

Study on interface between nuclear material accounting system and national nuclear forensic library

International Nuclear Information System (INIS)

Jeong, Yonhong; Han, Jae-Jun; Chang, Sunyoung; Shim, Hye-Won; Ahn, Seungho

2016-01-01

The implementation of nuclear forensics requires physical, chemical and radiological characteristics with transport history to unravel properties of seized nuclear materials. For timely assessment provided in the ITWG guideline, development of national response system (e.g., national nuclear forensic library) is strongly recommended. Nuclear material accounting is essential to obtain basic data in the nuclear forensic implementation phase from the perspective of nuclear non-proliferation related to the IAEA Safeguards and nuclear security. In this study, the nuclear material accounting reports were chosen due to its well-established procedure, and reviewed how to efficiently utilize the existing material accounting system to the nuclear forensic implementation phase In conclusion, limits and improvements in implementing the nuclear forensics were discussed. This study reviewed how to utilize the existing material accounting system for implementing nuclear forensics. Concerning item counting facility, nuclear material properties can be obtained based on nuclear material accounting information. Nuclear fuel assembly data being reported for the IAEA Safeguards can be utilized as unique identifier within the back-end fuel cycle. Depending upon the compulsory accountability report period, there exist time gaps. If national capabilities ensure that history information within the front-end nuclear fuel cycle is traceable particularly for the bulk handling facility, the entire cycle of national nuclear fuel would be managed in the framework of developing a national nuclear forensic library

Study on interface between nuclear material accounting system and national nuclear forensic library

Energy Technology Data Exchange (ETDEWEB)

Jeong, Yonhong; Han, Jae-Jun; Chang, Sunyoung; Shim, Hye-Won; Ahn, Seungho [Korea Institute of Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of)

2016-10-15

The implementation of nuclear forensics requires physical, chemical and radiological characteristics with transport history to unravel properties of seized nuclear materials. For timely assessment provided in the ITWG guideline, development of national response system (e.g., national nuclear forensic library) is strongly recommended. Nuclear material accounting is essential to obtain basic data in the nuclear forensic implementation phase from the perspective of nuclear non-proliferation related to the IAEA Safeguards and nuclear security. In this study, the nuclear material accounting reports were chosen due to its well-established procedure, and reviewed how to efficiently utilize the existing material accounting system to the nuclear forensic implementation phase In conclusion, limits and improvements in implementing the nuclear forensics were discussed. This study reviewed how to utilize the existing material accounting system for implementing nuclear forensics. Concerning item counting facility, nuclear material properties can be obtained based on nuclear material accounting information. Nuclear fuel assembly data being reported for the IAEA Safeguards can be utilized as unique identifier within the back-end fuel cycle. Depending upon the compulsory accountability report period, there exist time gaps. If national capabilities ensure that history information within the front-end nuclear fuel cycle is traceable particularly for the bulk handling facility, the entire cycle of national nuclear fuel would be managed in the framework of developing a national nuclear forensic library.

A multitasking, multisinked, multiprocessor data acquisition front end

International Nuclear Information System (INIS)

Fox, R.; Au, R.; Molen, A.V.

1989-01-01

The authors have developed a generalized data acquisition front end system which is based on MC68020 processors running a commercial real time kernel (rhoSOS), and implemented primarily in a high level language (C). This system has been attached to the back end on-line computing system at NSCL via our high performance ETHERNET protocol. Data may be simultaneously sent to any number of back end systems. Fixed fraction sampling along links to back end computing is also supported. A nonprocedural program generator simplifies the development of experiment specific code

The reprocessing-recycling of spent nuclear fuel. Actinides separation - Application to wastes management; Le traitement-recyclage du combustible nucleaire use. La separation des actinides - Application a la gestion des dechets

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

After its use in the reactor, the spent fuel still contains lot of recoverable material for an energetic use (uranium, plutonium), but also fission products and minor actinides which represent the residues of nuclear reactions. The reprocessing-recycling of the spent fuel, as it is performed in France, implies the chemical separation of these materials. The development and the industrial implementation of this separation process represent a major contribution of the French science and technology. The reprocessing-recycling allows a good management of nuclear wastes and a significant saving of fissile materials. With the recent spectacular rise of uranium prices, this process will become indispensable with the development of the next generation of fast neutron reactors. This book takes stock of the present and future variants of the chemical process used for the reprocessing of spent fuels. It describes the researches in progress and presents the stakes and recent results obtained by the CEA. content: the separation of actinides, a key factor for a sustainable nuclear energy; the actinides, a discovery of the 20. century; the radionuclides in nuclear fuels; the aquo ions of actinides; some redox properties of actinides; some complexing properties of actinide cations; general considerations about treatment processes; some characteristics of nuclear fuels in relation with their reprocessing; technical goals and specific constraints of the PUREX process; front-end operations of the PUREX process; separation and purification operations of the PUREX process; elaboration of finite products in the framework of the PUREX process; management and treatment of liquid effluents; solid wastes of the PUREX process; towards a joint management of uranium and plutonium: the COEX{sup TM} process; technical options of treatment and recycling techniques; the fuels of generation IV reactors; front-end treatment processes of advanced fuels; hydrometallurgical processes for future fuel

HINS Linac front end focusing system R and D

International Nuclear Information System (INIS)

Apollinari, G.; Carcagno, R.H.; Dimarco, J.; Huang, Y.; Kashikhin, V.V.; Orris, D.F.; Page, T.M.; Rabehl, R.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; Fermilab; Argonne

2008-01-01

This report summarizes current status of an R and D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process

The nuclear fuel cycle in the 21st century

International Nuclear Information System (INIS)

Todreas, Neil E.

2004-01-01

As we enter the 21st century and contemplate the deployment of Generation III+ machines and the development of Generation IV systems, the fuel cycle within which these reactors are to operate has become a predominant consideration. The four challenges to nuclear development of the 21st century of economics, safety, sustainability through spent fuel management and efficient fuel utilization, and proliferation resistance increasingly involve the front and back ends of the fuel cycle equally if not more than the design of the reactor which has reached a far higher level of maturity. It is tempting to accept the closed cycle with its promise of effective waste management as inevitable. The central questions, however, are the characteristics of the desired closed cycle, the relative advantages of thermal versus fast spectrum closed cycles, the character and pace of the transition to a closed cycle, and finally the most central question as to whether the closed cycle is indeed more desirable a choice than is an open cycle. The desired closed fuel cycle for the long term around which this paper is based is full actinide recycle with natural uranium feed and only fission products discharged to an ultimate waste repository. It is concluded that a major international research and development program to achieve this fuel cycle is important to pursue. However, the need to decide for the closed cycle and deploy it is not pressing for the next several decades. (author)

Apparatus for assembling and welding end plugs to nuclear fuel cladding tubes and inspecting the end plug welds on an automated basis

International Nuclear Information System (INIS)

Schoenig, F.C. Jr.; Walker, E.S.; Cueman, M.K.; Haughton, R.A.; Zuloaga, J.A. Jr.

1989-01-01

This patent describes an automated apparatus for welding a separate end plug to one open end of each of a succession of nuclear fuel cladding tubes and for inspecting each end plug weld. The apparatus comprising, in combination: a welding station; a cooldown station for cooling each end plug weld in an inert gas atmosphere; a serial number reader station for reading a serial number on each end plug; a first weld inspection station; a second weld inspection station for generating second weld inspection data; a computer system linked with the serial number reader and the first and second weld inspection stations; an input queue for holding a plurality of tubes; a tube transporter for periodically picking individual tubes from the input queque and conveying the tubes in a direction transverse to their tube axis in indexing steps to index positions respectively axially aligned with the welding, serial number reader, and first and second weld inspection stations; and a sorter positioned at an output end of the tube transporter

High Dynamic Range RF Front End with Noise Cancellation and Linearization for WiMAX Receivers

Directory of Open Access Journals (Sweden)

J.-M. Wu

2012-06-01

Full Text Available This research deals with verification of the high dynamic range for a heterodyne radio frequency (RF front end. A 2.6 GHz RF front end is designed and implemented in a hybrid microwave integrated circuit (HMIC for worldwide interoperability for microwave access (WiMAX receivers. The heterodyne RF front end consists of a low-noise amplifier (LNA with noise cancellation, an RF bandpass filter (BPF, a downconverter with linearization, and an intermediate frequency (IF BPF. A noise canceling technique used in the low-noise amplifier eliminates a thermal noise and then reduces the noise figure (NF of the RF front end by 0.9 dB. Use of a downconverter with diode linearizer also compensates for gain compression, which increases the input-referred third-order intercept point (IIP3 of the RF front end by 4.3 dB. The proposed method substantially increases the spurious-free dynamic range (DRf of the RF front end by 3.5 dB.

Nuclear fuel cycle head-end enriched uranium purification and conversion into metal

International Nuclear Information System (INIS)

Bonini, A.; Cabrejas, J.; Lio, L. de; Dell'Occhio, L.; Devida, C.; Dupetit, G.; Falcon, M.; Gauna, A.; Gil, D.; Guzman, G.; Neuringer, P.; Pascale, A.; Stankevicius, A.

1998-01-01

The CNEA (Comision Nacional de Energia Atomica - Argentina) operated two facilities at the Ezeiza Atomic Center which supply purified enriched uranium employed in the production of nuclear fuels. At one of those facilities, the Triple Height Laboratory scraps from the production of MTR type fuel elements (mainly out of specification U 3 O 8 plates or powder) are purified to nuclear grade. The purification is accomplished by a solvent extraction process. The other facility, the Enriched Uranium Laboratory produces 90% enriched uranium metal to be used in Mo 99 production (originally the uranium was used for the manufacture of MTR fuel elements made of aluminium-uranium alloy). This laboratory also provided metallic uranium with a lower enrichment (20%) for a first uranium-silicon testing fuel element, and in the near future it is going to recommence 20% enriched uranium related activities in order to provide the metal for the silicon-based fuel elements production (according to the policy of enrichment reduction for MTR reactors). (author)

Nuclear reactor core and fuel element therefor

International Nuclear Information System (INIS)

Fortescue, P.

1986-01-01

This patent describes a nuclear reactor core. This core consists of vertical columns of disengageable fuel elements stacked one atop another. These columns are arranged in side-by-side relationship to form a substantially continuous horizontal array. Each of the fuel elements include a block of refractory material having relatively good thermal conductivity and neutron moderating characteristics. The block has a pair of parallel flat top and bottom end faces and sides which are substantially prependicular to the end faces. The sides of each block is aligned vertically within a vertical column, with the sides of vertically adjacent blocks. Each of the blocks contains fuel chambers, including outer rows containing only fuel chambers along the sides of the block have nuclear fuel material disposed in them. The blocks also contain vertical coolant holes which are located inside the fuel chambers in the outer rows and the fuel chambers which are not located in the outer rows with the fuel chambers and which extend axially completely through from end face to end face and form continuous vertical intracolumn coolant passageways in the reactor core. The blocks have vertical grooves extending along the sides of the blocks form interblock channels which align in groups to form continuous vertical intercolumn coolant passsageways in the reactor core. The blocks are in the form of a regular hexagonal prism with each side of the block having vertical gooves defining one half of one of the coolant interblock channels, six corner edges on the blocks have vertical groves defining one-third of an interblock channel, the vertical sides of the blocks defining planar vertical surfaces

Fuel bundle for nuclear reactor

International Nuclear Information System (INIS)

Long, J.W.; Flora, B.S.; Ford, K.L.

1977-01-01

The invention concerns a new, simple and inexpensive system for assembling and dismantling a nuclear reactor fuel bundle. Several fuel rods are fitted in parallel rows between two retaining plates which secure the fuel rods in position and which are maintained in an assembled position by means of several stays fixed to the two end plates. The invention particularly refers to an improved apparatus for fixing the stays to the upper plate by using locking fittings secured to rotating sleeves which are applied against this plate [fr

Integration of the military and civilian nuclear fuel cycles in Russia

International Nuclear Information System (INIS)

Bukharin, O.

1994-01-01

This paper describes the close integration of the civil and military nuclear fuel cycles in Russia. Individual processing facilities, as well as the flow of nuclear material, are described as they existed in the 1980s and as they exist today. The end of the Cold War and the breakup of the Soviet Union weakened the ties between the two nuclear fuel cycles, but did not separate them. Separation of the military and civilian nuclear fuel cycles would facilitate Russia's integration into the world's nuclear fuel cycle and its participation in international non-proliferation regimes

Main attributes influencing spent nuclear fuel management

International Nuclear Information System (INIS)

Andreescu, N.; Ohai, D.

1997-01-01

All activities regarding nuclear fuel, following its discharge from the NPP, constitute the spent fuel management and are grouped in two possible back end variants, namely reprocessing (including HLW vitrification and geological disposal) and direct disposal of spent fuel. In order to select the appropriate variant it is necessary to analyse the aggregate fulfillment of the imposed requirements, particularly of the derived attributes, defined as distinguishing characteristics of the factors used in the decision making process. The main identified attributes are the following: - environmental impact, - availability of suitable sites, - non-proliferation degree, -strategy of energy, - technological complexity and technical maturity, -possible further technical improvements, - size of nuclear programme, - total costs, - public acceptance, - peculiarity of CANDU fuel. The significance of the attributes in the Romanian case, taking into consideration the present situation, as a low scenario and a high scenario corresponding to an important development of the nuclear power, after the year 2010, is presented. According to their importance the ranking of attributes is proposed . Subsequently, the ranking could be used for adequate weighing of attributes in order to realize a multi-criteria analysis and a relevant comparison of back end variants. (authors)

Strategies for the back end of the nuclear fuel cycle. Proceedings of a technical committee meeting held in Vienna, 1-4 June 1993

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

The selection of an option for the back end of the nuclear fuel cycle is an important decision for all countries with nuclear power programmes. Likewise, the process for making that option selection is also important. Some countries have begun utilizing nuclear energy for electricity generation without formally determining what would be done with the spent nuclear fuel and radioactive wastes. In a number of those countries the inventories of spent fuel are approaching their storage capacity - and an option selection must soon be made. This report provides an analysis of both the policies chosen by a number of Member States and the process that led to those selections. The intent of this analysis and this publication is to assist other countries in their deliberations on this subject. This publication presents conclusions concerning the factors that were considered important by different countries and the processes which they followed in making their determination of the policy for disposal of nuclear waste. Refs, figs, tabs.

Strategies for the back end of the nuclear fuel cycle. Proceedings of a technical committee meeting held in Vienna, 1-4 June 1993

International Nuclear Information System (INIS)

1995-11-01

The selection of an option for the back end of the nuclear fuel cycle is an important decision for all countries with nuclear power programmes. Likewise, the process for making that option selection is also important. Some countries have begun utilizing nuclear energy for electricity generation without formally determining what would be done with the spent nuclear fuel and radioactive wastes. In a number of those countries the inventories of spent fuel are approaching their storage capacity - and an option selection must soon be made. This report provides an analysis of both the policies chosen by a number of Member States and the process that led to those selections. The intent of this analysis and this publication is to assist other countries in their deliberations on this subject. This publication presents conclusions concerning the factors that were considered important by different countries and the processes which they followed in making their determination of the policy for disposal of nuclear waste. Refs, figs, tabs

Fast CMOS binary front-end for silicon strip detectors at LHC experiments

CERN Document Server

Kaplon, Jan

2004-01-01

We present the design and the test results of a front-end circuit developed in a 0.25 mu m CMOS technology. The aim of this work is to study the performance of a deep submicron process in applications for fast binary front-end for silicon strip detectors. The channel comprises a fast transimpedance preamplifier working with an active feedback loop, two stages of the amplifier-integrator circuits providing 22 ns peaking time and two-stage differential discriminator. Particular effort has been made to minimize the current and the power consumption of the preamplifier, while keeping the required noise and timing performance. For a detector capacitance of 20 pF noise below 1500 e/sup -/ ENC has been achieved for 300 mu A bias current in the input transistor, which is comparable with levels achieved in the past for a front-end using bipolar input transistor. The total supply current of the front-end is 600 mu A and the power dissipation is 1.5 mW per channel. The offset spread of the comparator is below 3 mV rms.

A Serializer ASIC at 5 Gbps for Detector Front-end Electronics Readout

CERN Document Server

Gong, D; The ATLAS collaboration; Liu, T; Xiang, A; Ye, J

2010-01-01

High speed and ultra low power serial data transmission over fiber optics plays an essential roll in detector front-end electronics readout for experiments at the LHC. The ATLAS Liquid Argon Calorimeter front-end readout upgrade for the sLHC calls for an optical link system with a data bandwidth of 100 Gbps per each front-end board (FEB), a factor of 62 increase compared with the present optical link system. The transmitter of this optical link will have to withstand the radiation environment where the front-end crates are situated, and stay within the current power dissipation budget limited by the present FEB cooling capacity. To meet these challenges, we developed a 16:1 serializer based on a commercial 0.25 μm silicon-on-sapphire (SOS) CMOS technology. This serializer, designed to work at 5 Gbps, is a key component in an optical link system. Test results of this ASIC will be reported. A system design for the 100 Gbps optical link system will also be presented, with discussions about key components identi...

Implementasi Analog Front End Pada Sensor Kapasitif Untuk Pengaturan Kelembaban Menggunakan Mikrokontroller STM32

Directory of Open Access Journals (Sweden)

Rendy Setiawan

2017-01-01

Full Text Available Sensor kapasitif merupakan jenis sensor yang mengubah stimulus fisik menjadi perubahan kapasitansi. Pada sensor kapasitif, adanya stray capacitance atau kapasitansi parasitik pada sensor dapat menyebabkan kesalahan dalam pengukuran. Dalam aplikasi pengaturan kelembaban, dibutuhkan sistem pengukuran kelembaban dengan kesalahan minimum untuk mendapatkan nilai setting point dengan galat minimum. Maka diperlukan implementasi analog front end yang dapat meminimalisir kesalahan akibat stray capacitance pada sensor kapasitif untuk pengukuran kelembaban relatif. Pada sistem pengukuran sensor kapasitif ini, sensor dieksitasi dengan sinyal AC yang dihasilkan oleh generator sinyal pada frekuensi 10 KHz, kemudian diimplementasikan analog front end untuk mengondisikan sinyal dari sensor. Keluaran dari analog front end dikonversi menjadi sinyal DC menggunakan demodulator sinkron dan filter low pass lalu dikonversi menjadi data digital menggunakan ADC di mikrokontroller STM32. Hasil pengukuran yang didapatkan dengan implementasi analog front end kemudian kemudian gunakan untuk mengatur kelembaban pada sebuah plant growth chamber. Berdasarkan hasil dari pengujian, rangkaian analog front end dapat mengompensasi stray capacitance dengan kesalahan pembacaan nilai kapasitansi maksimal sebesar 4.2% pada kondisi stray capacitance sebesar 236,6pF, 174,3pF dan 115,7pF. Implementasi analog front end pada pengaturan kelembaban menghasilkan galat pada setting point maksimal sebesar 8.8% untuk nilai RH 75% dan 33%.

A tunable RF Front-End with Narrowband Antennas for Mobile Devices

DEFF Research Database (Denmark)

Bahramzy, Pevand; Olesen, Poul; Madsen, Peter

2015-01-01

desensitization due to the Tx signal. The filters and antennas demonstrate tunability across multiple bands. System validation is detailed for LTE band I. Frequency response, as well as linearity measurements of the complete Tx and Rx front-end chains, show that the system requirements are fulfilled.......In conventional full-duplex radio communication systems, the transmitter (Tx) is active at the same time as the receiver (Rx). The isolation between the Tx and the Rx is ensured by duplex filters. However, an increasing number of long-term evolution (LTE) bands crave multiband operation. Therefore......, a new front-end architecture, addressing the increasing number of LTE bands, as well as multiple standards, is presented. In such an architecture, the Tx and Rx chains are separated throughout the front-end. Addition of bands is solved by making the antennas and filters tunable. Banks of duplex filters...

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XIX, I--ENGINE TUNE-UP--CUMMINS DIESEL ENGINE, II--FRONT END SUSPENSION AND AXLES.

Science.gov (United States)

Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF DIESEL ENGINE TUNE-UP PROCEDURES AND THE DESIGN OF FRONT END SUSPENSION AND AXLES USED ON DIESEL ENGINE EQUIPMENT. TOPICS ARE (1) PRE-TUNE-UP CHECKS, (2) TIMING THE ENGINE, (3) INJECTOR PLUNGER AND VALVE ADJUSTMENTS, (4) FUEL PUMP ADJUSTMENTS ON THE ENGINE (PTR AND PTG),…

Remote technology in the spent fuel route in the UK

International Nuclear Information System (INIS)

Webster, A.W.

1999-01-01

Remote technologies employed in front end (commercial) reprocessing operations of metallic and oxide fuel at Sellafield in the UK are described. An overview of the transportation, fuel receiving and preparation facilities are given together with the remote technology developments employed to improve operations. It is concluded that the facilities and remote technology used within them are mature and based upon simple and robust principles. Remote operations and maintenance in these facilities is often easier than in many facilities downstream of the dissolution stage. Fuel design considerations for shearing and handling are described and it is concluded that advanced and higher burnup fuel can be accommodated by existing reprocessing and interim storage routes with current remote technologies. Two different storage systems are available from UK companies which use existing spent fuel handling technology/equipment. The pace of remote technology development is currently being set by the demands of other nuclear process areas such as decommissioning and plant clean out; these will spin-off into front end processes. (author)

Method of manufacturing nuclear fuel elements

International Nuclear Information System (INIS)

Ishida, Masao; Oguma, Masaomi.

1980-01-01

Purpose: To effectively prevent the bending of nuclear fuel elements in the reactor by grinding the end faces of pellets due to their mutual sliding. Method: In the manufacturing process of nuclear fuel elements, a plurality of pellets whose sides have been polished are fed one by one by way of a feeding mechanism through the central aperture in an electric motor into movable arms and retained horizontally with the central axis by being held on the side. Then, the pellet held by one of the arms is urged to another pellet held by the other of the arms by way of a pressing mechanism and the mating end faces of both of the pellets are polished by mutual sliding. Thereafter, the grinding dusts resulted are eliminated by drawing pressurized air and then the pellets are enforced into a cladding tube. Thus, the pellets are charged into the cladding tube with both polished end faces being contacted to each other, whereby the axial force is uniformly transmitted within the end faces to prevent the bending of the cladding tube. (Kawakami, Y.)

Pixel front-end development in 65 nm CMOS technology

International Nuclear Information System (INIS)

Havránek, M; Hemperek, T; Kishishita, T; Krüger, H; Wermes, N

2014-01-01

Luminosity upgrade of the LHC (HL-LHC) imposes severe constraints on the detector tracking systems in terms of radiation hardness and capability to cope with higher hit rates. One possible way of keeping track with increasing luminosity is the usage of more advanced technologies. Ultra deep sub-micron CMOS technologies allow a design of complex and high speed electronics with high integration density. In addition, these technologies are inherently radiation hard. We present a prototype of analog pixel front-end integrated circuit designed in 65 nm CMOS technology with applications oriented towards the ATLAS Pixel Detector upgrade. The aspects of ultra deep sub-micron design and performance of the analog pixel front-end circuits will be discussed

A study on the front-end VME system of BEPC II

International Nuclear Information System (INIS)

Wang Chunhong

2004-01-01

The front-end VME system is not only the heart of the control system, but also a real-time system. This paper describes the component of the front-end VME (Versa Module Eurocard) system including control computer and some related I/O modules. Particularly, the authors present a best solution for the problems about Vx-Works kernel and BSP running on MVME5100. This is a fundamental setup of the BEPC II control system. (author)

Nuclear fuel

International Nuclear Information System (INIS)

D Hondt, P.

1998-01-01

The research and development programme on nuclear fuel at the Belgian Nuclear Research Centre SCK/CEN is described. The objective of this programme is to enhance the quantitative prediction of the operational limits of nuclear fuel and to assess the behaviour of fuel under incidental and accidental conditions. Progress is described in different domains including the modelling of fission gas release in LWR fuel, thermal conductivity, basic physical phenomena, post-irradiation examination for fuel performance assessment, and conceptual studies of incidental and accidental fuel experiments

A 500μW 5Mbps ULP super-regenerative RF front-end

NARCIS (Netherlands)

Vidojkovic, M.; Rampu, S.; Imamura, K.; Harpe, P.; Dolmans, G.; Groot, H. de

2010-01-01

This paper presents an ultra low power super-regenerative RF front-end for wireless body area network (WBAN) applications. The RF front-end operates in the 2.36-2.4 GHz medical BAN and 2.4-2.485 GHz ISM bands, and consumes 500 μW. It supports OOK modulation at high data rates ranging from 1-5 Mbps.

Functional description of APS beamline front ends

International Nuclear Information System (INIS)

Kuzay, T.

1993-02-01

Traditional synchrotron sources were designed to produce bending magnet radiation and have proven to be an essential scientific tool. Currently, a new generation of synchrotron sources is being built that will be able to accommodate a large number of insertion device (ID) and high quality bending magnet (BM) sources. One example is the 7-GeV Advanced Photon Source (APS) now under construction at Argonne National Laboratory. The research and development effort at the APS is designed to fully develop the potential of this new generation of synchrotron sources. Of the 40 straight sections in the APS storage ring, 34 will be available for IDs. The remaining six sections are reserved for the storage ring hardware and diagnostics. Although the ring incorporates 80 BMs, only 40 of them can be used to extract radiation. The accelerator hardware shadows five of these 40 bending magnets, so the maximum number of BM sources on the lattice is 35. Generally, a photon beamline consists of four functional sections. The first section is the ID or the BM, which provides the radiation source. The second section, which is immediately outside the storage ring but inside a concrete shielding tunnel, is the front end, which is designed to control, define, and/or confine the x-ray beam. In the case of the APS, the front ends are designed to confine the photon beam. The third section, just outside the concrete shielding tunnel and on the experimental floor, is the first optics enclosure, which contains optics to filter and monochromatize the photon beam. The fourth section of a beamline consists of beam transports, additional optics, and experiment stations to do the scientific investigations. This document describes only the front ends of the APS beamlines

The nuclear fuel cycle, an overview

International Nuclear Information System (INIS)

Ballery, J.L.; Cazalet, J.; Hagemann, R.

1995-01-01

Because uranium is widely distributed on the face of the Earth, nuclear energy has a very large potential as an energy source in view of future depletion of fossil fuel reserves. Also future energy requirements will be very sizeable as populations of developing countries are often growing and make the energy question one of the major challenges for the coming decades. Today, nuclear contributes some 340 GWe to the energy requirements of the world. Present and future nuclear programs require an adequate fuel cycle industry, from mining, refining, conversion, enrichment, fuel fabrication, fuel reprocessing and the storage of the resulting wastes. The commercial fuel cycle activities amount to an annual business in the 7-8 billions of US Dollars in the hands of a large number of industrial operators. This paper gives details about companies and countries involved in each step of the fuel cycle and about the national strategies and options chosen regarding the back end of the fuel cycle (waste storage and reprocessing). These options are illustrated by considering the policy adopted in three countries (France, United Kingdom, Japan) versed in reprocessing. (J.S.). 13 figs., 2 tabs

Precedents for diversion-resistant nuclear fuel cycles

International Nuclear Information System (INIS)

Culler, F.L. Jr.

1978-01-01

The urgent need to limit the spread of nuclear weapons and to control the means of production of fissionable material has been the dominant force in the worldwide development of civilian nuclear power. The author follows the historical perspective for institutional control. To improve diversion resistance of the back end of the fuel recycle, the Civex process is proposed. The Civex process does not use new separation process principles or new methods for fuel fabrication. Rather, it is a combination of processes used and partially developed techniques for breeder fuel reprocessing and refabrication. Its characteristics are listed. The process steps and the design knowledge to meet these criteria, and to operate under conditions that provide maximum diversion resistance, can be adaptations of methods studied earlier and, in most cases, used for both military and civilian fuel recycle. The adaptations change the original techniques enough to make the technology different from that used for existing power reactors. The author discusses tried or partially demonstrated techniques from which Civex has been or could be fashioned. Separation processes discussed are bismuth phosphate; Purex; Thorex; fluoride volatility; pyrometallurgy. The Sol--Gel Uranium--Plutonium Spherepak and Pellet Fuels processes are discussed as candidates for Civex fuel-production methods. The author concludes that, in his opinion, the Civex process is as far as technology can go in the back end of the nuclear fuel cycle from illicit diversion of fissile materials

2008 annual meeting on nuclear technology. Pt. 1. Section reports

International Nuclear Information System (INIS)

Dagan, Ron; Sanchez Espinoza, Victor Hugo; Faber, Wolfgang; Berlepsch, Thilo v.; Spann, Holger; Schaffrath, Andreas; Schubert, Bernd; Rieger, Udo; Christ, Bernhard G.; Gulden, Werner; Bogusch, Edgar

2008-01-01

Summary report on these 5 - out of 11 - Sections of the Annual Conference on Nuclear Technology held in Hamburg on May 27-29, 2008: - Reactor Physics and Methods of Calculation - Thermodynamics and Fluid Dynamics - Safety of Nuclear Installations - Methods, Analysis, Results - Front End and Back End of the Fuel Cycle, Radioactive Waste, Storage - Fusion Technology. Other Sections will be covered in reports in further issues of atw. (orig.)

SMART instruments for radiological surveillance at the back end of nuclear fuel cycle

International Nuclear Information System (INIS)

Pendharkar, K.A.; Jauhri, G.S.; Ganesh, G.; Kulkarni, V.V.

2001-01-01

The back end of Nuclear Fuel Cycle mainly consists of Fuel Reprocessing Plant and Waste Management Plant for treatment of different types of wastes generated during processing of spent fuel. A fuel reprocessing plant handles annually several million curies of fission product activity and few hundred kg of plutonium. A Waste Management Facility associated with a reprocessing plant also handles several million curies of fission product activity. In both the plants several types of radiological measurements have to be carried out to ensure that the individual doses are well below regulatory limits and release of radioactivity to environment (through stack and through liquid effluent) is below the limit stipulated in technical specifications of the plant. The measurements comprise individual external dose, measurement of radiation level in different areas of the plant, assessment of air-borne activity due to plutonium and fission products in different areas of the plant, radioactivity release to environment through liquid effluents and through stack. In order to carry out the above mentioned measurements large number of different types of instruments are required. The existing instruments are analog instruments. These instruments have served well. However they have certain limitations with respect to flexibility and extra functionality. In this respect the 'SMART' instruments have distinct advantages. The advantages, that are offered by the 'SMART' instrument in making the radiological surveillance programme more effective, are brought out in the paper. (author)

Fuel assemblies for nuclear reactors

International Nuclear Information System (INIS)

Jabsen, F.S.

1979-01-01

In a nuclear fuel assembly, hollow guide posts protrude into a fuel assembly and fitting grill from a biased spring pad with a plunger that moves with the spring pad plugging one end of each of the guide posts. A plate on the end fitting grill that has a hole for fluid discharge partially plugs the other end of the guide post. Pressurized water coolant that fills the guide post volume acts as a shock absorber and should the reactor core receive a major seismic or other shock, the fuel assembly is compelled to move towards a pad depending from a transversely disposed support grid. The pad bears against the spring pad and the plunger progressively blocks the orifices provided by slots in the guide posts thus gradually absorbing the applied shock. After the orifice has been completely blocked, controlled fluid discharge continues through a hole coil spring cooperating in the attenuation of the shock. (author)

Building world-wide nuclear industry success stories - Safe management of nuclear waste and used nuclear fuel

International Nuclear Information System (INIS)

Saint-Pierre, S.

2005-01-01

Full text: This WNA Position Statement summarizes the worldwide nuclear industry's record, progress and plans in safely managing nuclear waste and used nuclear fuel. The global industry's safe waste management practices cover the entire nuclear fuel-cycle, from the mining of uranium to the long-term disposal of end products from nuclear power reactors. The Statement's aim is to provide, in clear and accurate terms, the nuclear industry's 'story' on a crucially important subject often clouded by misinformation. Inevitably, each country and each company employs a management strategy appropriate to a specific national and technical context. This Position Statement reflects a confident industry consensus that a common dedication to sound practices throughout the nuclear industry worldwide is continuing to enhance an already robust global record of safe management of nuclear waste and used nuclear fuel. This text focuses solely on modern civil programmes of nuclear-electricity generation. It does not deal with the substantial quantities of waste from military or early civil nuclear programmes. These wastes fall into the category of 'legacy activities' and are generally accepted as a responsibility of national governments. The clean-up of wastes resulting from 'legacy activities' should not be confused with the limited volume of end products that are routinely produced and safely managed by today's nuclear energy industry. On the significant subject of 'Decommissioning of Nuclear Facilities', which is integral to modern civil nuclear power programmes, the WNA will offer a separate Position Statement covering the industry's safe management of nuclear waste in this context. The safe management of nuclear waste and used nuclear fuel is a widespread, well-demonstrated reality. This strong safety record reflects a high degree of nuclear industry expertise and of industry responsibility toward the well-being of current and future generations. Accumulating experience and

Storage of thermal reactor fuels - Implications for the back end of the fuel cycle in the UK

International Nuclear Information System (INIS)

Hambley, D.

2016-01-01

Fuel from UK's Advanced Gas-Cooled Reactors (AGRs) is being reprocessed, however reprocessing will cease in 2018 and the strategy for fuel that has not been reprocessed is for it to be placed into wet storage until it can be consigned to a geological disposal facility in around 2080. Although reprocessing of LWR fuel has been undertaken in the UK, and this option is not precluded for current and future LWRs, all utilities planning to operate LWRs are intending to use At-Reactor storage pending geological disposal. This strategy will result in a substantial change in the management of spent fuel that could affect the back end of the fuel cycle for over a century. This paper presents potential fuel storage scenarios for two options: the current nuclear power replacement strategy, which will see 16 GWe of new capacity installed by 2030 and a median strategy, intended to ensure implementation of the UK's carbon reduction target, involving 48 GWe of nuclear capacity installed by 2040. The potential scale, distribution and timing of fuel storage and disposal operations have been assessed and changes to the current industrial activity are highlighted to indicate potential effects on public acceptance of back end activities. (authors)

Front-end electronics for multichannel semiconductor detector systems

CERN Document Server

Grybos, P

2010-01-01

Front-end electronics for multichannel semiconductor detektor systems Volume 08, EuCARD Editorial Series on Accelerator Science and Technology The monograph is devoted to many different aspects related to front-end electronics for semiconductor detector systems, namely: − designing and testing silicon position sensitive detectors for HEP experiments and X-ray imaging applications, − designing and testing of multichannel readout electronics for semiconductor detectors used in X-ray imaging applications, especially for noise minimization, fast signal processing, crosstalk reduction and good matching performance, − optimization of semiconductor detection systems in respect to the effects of radiation damage. The monograph is the result mainly of the author's experience in the above-mentioned areas and it is an attempt of a comprehensive presentation of issues related to the position sensitive detection system working in a single photon counting mode and intended to X-ray imaging applications. The structure...

Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

Science.gov (United States)

Prele, D.

2015-08-01

As we have seen for digital camera market and a sensor resolution increasing to "megapixels", all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, "simple" and "efficient" techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described.

Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

International Nuclear Information System (INIS)

Prele, D.

2015-01-01

As we have seen for digital camera market and a sensor resolution increasing to 'megapixels', all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, 'simple' and 'efficient' techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described

Means for supporting nuclear fuel

International Nuclear Information System (INIS)

Cocker, P.; Price, M.A.

1975-01-01

Reference is made to means for supporting nuclear fuel pins in a reactor coolant channel and the problems that arise in this connection. For reasons of nuclear reactivity and neutron economy 'parasitic' material in a reactor core must be kept to a minimum, whilst for heat transfer reasons the use of fuel pins of large cross-sectional areas should be avoided. Fuel pins tend to be long thin objects having a can of minimum thickness and typically a pin may have a length/diameter ratio of about 500/1 and for fast reactor fuel pins, the outside diameter may be about 0.2 inch. The long slender pins must also be spaced very close together. A fast reactor fuel assembly may involve 200 to 300 fuel pins, each a few tenths of an inch in diameter, supported end on to coolant flowing up a channel of about 22 square inches in total area. The pins have a heavy metal oxide filling and require support. Details are given of a suitable method of support. Such support also allows withdrawal of pins from a fuel channel without the risk of breach of the can, after irradiation. (U.K.)

Status of nuclear fuel reprocessing, spent fuel storage, and high-level waste disposal. Nuclear Fuel Cycle Committee, California Energy Resources Conservation and Development Commission. Draft report

International Nuclear Information System (INIS)

Anon.

1978-01-01

An analysis of the current status of technologies and issues in the major portions of the back-end of the nuclear fuel cycle is presented. The discussion on nuclear fuel reprocessing covers the reprocessing requirement, reprocessing technology assessment, technology for operation of reprocessing plants, and approval of reprocessing plants. The chapter devoted to spent fuel storage covers the spent fuel storge problem, the legislative response, options for maintaining full core discharge capacity, prospective availability of alterntive storage options, and the outlook for California. The existence of a demonstrated, developed high-level waste disposal technology is reviewed. Recommendations for Federal programs on high-level waste disposal are made

Report on the value engineering workshop on APS beamline front ends

International Nuclear Information System (INIS)

Kuzay, T.

1993-01-01

A formal value engineering evaluation process was developed to address the front end components of the beamlines for the Advanced Photon Source (APS). This process (described in Section 2) involved an information phase, a creative phase, a judgment phase, a development phase, and a recommendation phase. Technical experts from other national laboratories and industry were invited to a two-day Value Engineering Workshop on November 5-6, 1992. The results of this Workshop are described in Section 4. Following the Workshop, various actions by the APS staff led to the redesign of the front end components, which are presented in Sections 5 and 6. The cost benefit analysis is presented in Section 7. It is important of realize that an added benefit of the Workshop was to obtain numerous design evaluations and enhancements of the front end components by experts in the field. As the design work proceeds to Title II completion, the APS staff is including many of these suggestions

Front-end electronics for accurate energy measurement of double beta decays

International Nuclear Information System (INIS)

Gil, A.; Díaz, J.; Gómez-Cadenas, J.J.; Herrero, V.; Rodriguez, J.; Serra, L.; Toledo, J.; Esteve, R.; Monzó, J.M.; Monrabal, F.; Yahlali, N.

2012-01-01

NEXT, a double beta decay experiment that will operate in Canfranc Underground Laboratory (Spain), aims at measuring the neutrinoless double-β decay of the 136Xe isotope using a TPC filled with enriched Xenon gas at high pressure operated in electroluminescence mode. One technological challenge of the experiment is to achieve resolution better than 1% in the energy measurement using a plane of UV sensitive photomultipliers readout with appropriate custom-made front-end electronics. The front-end is designed to be sensitive to the single photo-electron to detect the weak primary scintillation light produced in the chamber, and also to be able to cope with the electroluminescence signal (several hundred times higher and with a duration of microseconds). For efficient primary scintillation detection and precise energy measurement of the electroluminescent signals the front-end electronics features low noise and adequate amplification. The signal shaping provided allows the digitization of the signals at a frequency as low as 40 MHz.

Nuclear fuel element nut retainer cup

International Nuclear Information System (INIS)

Walton, L.A.

1977-01-01

A typical embodiment has an end fitting for a nuclear reactor fuel element that is joined to the control rod guide tubes by means of a nut plate assembly. The nut plate assembly has an array of nuts, each engaging the respective threaded end of the control rod guide tubes. The nuts, moreover, are retained on the plate during handling and before fuel element assembly by means of hollow cylindrical locking cups that are brazed to the plate and loosely circumscribe the individual enclosed nuts. After the nuts are threaded onto the respective guide tube ends, the locking cups are partially deformed to prevent one or more of the nuts from working loose during reactor operation. The locking cups also prevent loose or broken end fitting parts from becoming entrained in the reactor coolant

Nuclear fuel activity with minor actinides after their useful life in a BWR

International Nuclear Information System (INIS)

Martinez C, E.; Ramirez S, J. R.; Alonso V, G.

2016-09-01

Nuclear fuel used in nuclear power reactors has a life cycle, in which it provides energy, at the end of this cycle is withdrawn from the reactor core. This used fuel is known as spent nuclear fuel, a strong problem with this fuel is that when the fuel was irradiated in a nuclear reactor it leaves with an activity of approximately 1.229 x 10 15 Bq. The aim of the transmutation of actinides from spent nuclear fuel is to reduce the activity of high level waste that must be stored in geological repositories and the lifetime of high level waste; these two achievements would reduce the number of necessary repositories, as well as the duration of storage. The present work is aimed at evaluating the activity of a nuclear fuel in which radioactive actinides could be recycled to remove most of the radioactive material, first establishing a reference of actinides production in the standard nuclear fuel of uranium at end of its burning in a BWR, and a fuel rod design containing 6% of actinides in an uranium matrix from the enrichment tails is proposed, then 4 standard uranium fuel rods are replaced by 4 actinide bars to evaluate the production and transmutation of the same, finally the reduction of actinide activity in the fuel is evaluated. (Author)

Digital front-end module (DFEM) series; Digital front end module (DFEM) series

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

The digital front-end module (DFEM) is a module in which the processes ranging from the reception of digitally modulated radiofrequencies to the output of digital IF (Intermediate Frequency) signals or data streams are integrated. Beginning with a module for the MCNS (Multimedia Cable Network System) cable modem which was the first module in this business field approved by the Cable Labs, U.S., Toshiba has developed a series of DFEMs for various digital media for satellites, ground waves, and CATV (Cable Television) systems. The series is characterized by (1) the serialization of DFEMs compatible with various digital modulation techniques such as 8 PSK (Phase Shift Keying), OFDM (Orthogonal Frequency Division Multiplexing), and 256 QAM (Quadrature Amplitude Modulation), (2) easy connection with digital circuits thanks to the high shielding effect, and (3) the achievement of smaller size, higher performance, and lower power consumption. (translated by NEDO)

Flexible Frequency Discrimination Subsystems for Reconfigurable Radio Front Ends

Directory of Open Access Journals (Sweden)

Carey-Smith Bruce E

2005-01-01

Full Text Available The required flexibility of the software-defined radio front end may currently be met with better overall performance by employing tunable narrowband circuits rather than pursuing a truly wideband approach. A key component of narrowband transceivers is appropriate filtering to reduce spurious spectral content in the transmitter and limit out-of-band interference in the receiver. In this paper, recent advances in flexible, frequency-selective, circuit components applicable to reconfigurable SDR front ends are reviewed. The paper contains discussion regarding the filtering requirements in the SDR context and the use of intelligent, adaptive control to provide environment-aware frequency discrimination. Wide tuning-range frequency-selective circuit elements are surveyed including bandpass and bandstop filters and narrowband tunable antennas. The suitability of these elements to the mobile wireless SDR environment is discussed.

Holddown device for nuclear fuel assembly

International Nuclear Information System (INIS)

Anthony, A.J.

1978-01-01

An apparatus for preventing ''floating'' of nuclear-reactor fuel assemblies due to hydraulic forces is disclosed. The apparatus uses a holddown column made of the same material as the core barrel. The column is positioned in a center guide-tube location in the fuel assembly in such a manner as to enable it either to slide within the center guide tube or, if the center guide tube is replaced by the column, to slide through openings in the spacer grids. The lower end of the holddown column engages the lower end fitting of the fuel assembly, and the upper end of the column engages a flow plate to which holddown force is applied. As a consequence of this arrangement, holddown force is transmitted from the flow plate through the holddown column to the lower end fitting. Movement of the fuel assembly is thereby prevented without a compression load being applied to the fuel-assemb1ly structure. In addition, variations due to thermal expansion in the distance between the lower core plate and the upper core plate are largely made up for by corresponding variations in the holddown column because the holddown column and the core barrel can be made of the same material

MTR spent fuel back-end - Cogema's long-term commitment

International Nuclear Information System (INIS)

Thomasson, J.

1998-01-01

be reprocessed. This new fuel should be available within 10 years to provide a steady Back End solution for Research Reactors spent fuels, at the end of the new US Return Policy. COGEMA wishes to be able, as for Aluminides, to propose for that new fuel a Long Term Back End solution, including all the spent fuel management operations, to allow Reactors' operators to focus on their research activities. Such a partnership should provide reactors' operators with smooth operations, which is necessary for a long-term development of Nuclear Energy. (author)

Impact of extended burnup on the nuclear fuel cycle

International Nuclear Information System (INIS)

1993-04-01

The Advisory Group Meeting was held in Vienna from 2 to 5 December 1991, to review, analyse, and discuss the effects of burnup extension in both light and heavy water reactors on all aspects of the fuel cycle. Twenty experts from thirteen countries participated in this meeting. There was consensus that both economic and environmental benefits are driving forces toward the achievement of higher burnups and that the present trend of burnup extension may be expected to continue. The extended burnup has been considered for the three main stages of the fuel cycle: the front end, in-reactor issues and the back end. Thirteen papers were presented. A separate abstract was prepared for each of these papers. Refs, figs and tabs

Nuclear spent fuel management. Experience and options

International Nuclear Information System (INIS)

1986-01-01

Spent nuclear fuel can be stored safely for long periods at relatively low cost, but some form of permanent disposal will eventually be necessary. This report examines the options for spent fuel management, explores the future prospects for each stage of the back-end of the fuel cycle and provides a thorough review of past experience and the technical status of the alternatives. Current policies and practices in twelve OECD countries are surveyed

A European perspective on the US nuclear fuel cycle

International Nuclear Information System (INIS)

Wilkinson, W.L.

1989-01-01

Many Europeans believe that the main problems which have impeded progress in solving the back end of the nuclear fuel cycle in the United States have been a series of ideological and political hang-ups and these, coupled with excessive bureaucracy, have made logical decision making on the back-end problems impossible. This situation has been caused by a succession of political nondecisions. Public confidence in nuclear generation was thereby undermined and, because of plentiful supplies of other energy sources, there was no urgent need to expand the nuclear program in the United States. Since uranium was cheap and fast reactors not commercially attractive, there was no economic incentive to reprocess fuel from existing reactors in the United States. The problem facing the United States is that of managing the large stocks of spent fuel which have arisen over many years. A logical way forward for the United States would appear to be as follows: build more storage for spent fuel; consider overseas reprocessing to provide plutonium; develop reprocessing technology; and develop direct disposal technology

Nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Nakano, H [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)

1976-10-01

It is expected that nuclear power generation will reach 49 million kW in 1985 and 129 million kW in 1995, and the nuclear fuel having to be supplied and processed will increase in proportion to these values. The technical problems concerning nuclear fuel are presented on the basis of the balance between the benefit for human beings and the burden on the human beings. Recently, especially the downstream of nuclear fuel attracts public attention. Enriched uranium as the raw material for light water reactor fuel is almost monopolized by the U.S., and the technical information has not been published for fear of the diversion to nuclear weapons. In this paper, the present situations of uranium enrichment, fuel fabrication, transportation, reprocessing and waste disposal and the future problems are described according to the path of nuclear fuel cycle. The demand and supply of enriched uranium in Japan will be balanced up to about 1988, but afterwards, the supply must rely upon the early establishment of the domestic technology by centrifugal separation method. No problem remains in the fabrication of light water reactor fuel, but for the fabrication of mixed oxide fuel, the mechanization of the production facility and labor saving are necessary. The solution of the capital risk for the construction of the second reprocessing plant is the main problem. Japan must develop waste disposal techniques with all-out efforts.

Osiris: an object oriented software tool for modelling the logistics, economics and environmental impact of the nuclear fuel cycle

International Nuclear Information System (INIS)

Millington, D.N.

2003-01-01

Osiris is a general purpose software tool which has been developed for performing studies of material usage, economics and environmental impacts associated with the nuclear fuel cycle. It is particularly suited to the analysis of complex multiple recycling scenarios featuring combinations of both existing and new reactor systems. A discrete event model is used to represent the movement of material batches around the fuel cycle due to the operations and timings of process plants. Nuclear materials are represented by state vectors, which undergo compositional changes due to radioactive decay and irradiation. A library of generic plant types is provided, which are declared and configured in order to represent specific plants. Reactors, front-end and back-end process plants, buffers, stores and material sources can be modelled. Fuel cycle scenarios are then constructed by defining the material flow paths between the plants. The plant parameters and flow paths can be altered dynamically over the course of a scenario in order to represent changes in recycling strategies and retirement and replacement of process plants. Discounted electricity costs can be determined by assigning unit costs to all capital investments, processes and raw materials. Radiotoxicity levels of waste streams can also be evaluated. The software was developed in C++ using objected oriented analysis and design methods. The use of abstraction and inheritance have enabled an open-ended fuel cycle modelling environment to be established, into which new reactor or plant models can readily be integrated. An overview of the object model, numerical modelling assumptions and the design and implementation of the software is presented. (author)

Managing Controversies in the Fuzzy Front End

DEFF Research Database (Denmark)

Christiansen, John K.; Gasparin, Marta

2016-01-01

. The analysis investigates the microprocesses around the controversies that emerge during the fuzzy front end of four products. Five different types of controversies are identified: profit, production, design, brand and customers/market. Each controversy represents a threat, but also an opportunity to search...... for new solutions in the unpredictable non-linear processes. The study uses an ethnographic approach using qualitative data from interviews, company documents, external communication and marketing material, minutes of meetings, informal conversations and observations. The analysis of four FFE processes...... demonstrates how the fuzzy front requires managers to deal with controversies that emerge from many different places and involve both human and non-human actors. Closing the controversies requires managers to take account of the situation, identify the problem that needs to be addressed, and initiate a search...

Elements of nuclear reactor fueling theory

International Nuclear Information System (INIS)

Egan, M.R.

1984-01-01

Starting with a review of the simple batch size effect, a more general theory of nuclear fueling is derived to describe the behavior and physical requirements of operating cycle sequences and fueling strategies having practical use in the management of nuclear fuel. The generalized theory, based on linear reactivity modeling, is analytical and represents the effects of multiple-stream, multiple-depletion-batch fueling configurations in systems employing arbitrary, non-integer batch size strategies, and containing fuel with variable energy generation rates. Reactor operating cycles and cycle sequences are represented with realistic structure that includes the effects of variable cycle energy production, cycle lengths, end-of-cycle operating extensions and maneuvering allowances. Results of the analytical theory are first applied to the special case of degenerate equilibrium cycle sequences, yielding several fundamental principles related to the selection of refueling strategy, and which govern fueling decisions normally made by the fuel manager. It is also demonstrated in this application that the simple batch size effect is not valid for non-integer fueling strategies, even in the simplest sequence configurations, and that it systematically underestimates the fueling requirements of degenerate sequences in general

Engineered safeguards system activities at Sandia Laboratories for back-end fuel cycle facilities

International Nuclear Information System (INIS)

Sellers, T.A.; Fienning, W.C.; Winblad, A.E.

1978-01-01

Sandia Laboratories have been developing concepts for safeguards systems to protect facilities in the back-end of the nuclear fuel cycle against potential threats of sabotage and theft of special nuclear material (SNM). Conceptual designs for Engineered Safeguards Systems (ESSs) have been developed for a Fuel Reprocessing Facility (including chemical separations, plutonium conversion, and waste solidification), a Mixed-Oxide Fuel Fabrication Facility, and a Plutonium Transport Vehicle. Performance criteria for the various elements of these systems and a candidate systematic design approach have been defined. In addition, a conceptual layout for a large-scale Fuel-Cycle Plutonium Storage Facility has been completed. Work is continuing to develop safeguards systems for spent fuel facilities, light-water reactors, alternative fuel cycles, and improved transportation systems. Additional emphasis will be placed on the problems associated with national diversion of special nuclear material. The impact on safeguards element performance criteria for surveillance and containment to protect against national diversion in various alternative fuel cycle complexes is also being investigated

WNA position statement on safe management of nuclear waste and used nuclear fuel

International Nuclear Information System (INIS)

Saint-Pierre, S.

2006-01-01

This World nuclear association (W.N.A.) Position Statement summarizes the worldwide nuclear industry's record, progress and plans in safely managing nuclear waste and used nuclear fuel. The global industry's safe waste management practices cover the entire nuclear fuel-cycle, from the mining of uranium to the long-term disposal of end products from nuclear power reactors. The Statement's aim is to provide, in clear and accurate terms, the nuclear industry's 'story' on a crucially important subject often clouded by misinformation. Inevitably, each country and each company employs a management strategy appropriate to a specific national and technical context. This Position Statement reflects a confident industry consensus that a common dedication to sound practices throughout the nuclear industry worldwide is continuing to enhance an already robust global record of safe management of nuclear waste and used nuclear fuel. This text focuses solely on modern civil programmes of nuclear-electricity generation. It does not deal with the substantial quantities of waste from military or early civil nuclear programmes. These wastes fall into the category of 'legacy activities' and are generally accepted as a responsibility of national governments. The clean-up of wastes resulting from 'legacy activities' should not be confused with the limited volume of end products that are routinely produced and safely managed by today's nuclear energy industry. On the significant subject of 'Decommissioning of Nuclear Facilities', which is integral to modern civil nuclear power programmes, the W.N.A. will offer a separate Position Statement covering the industry's safe management of nuclear waste in this context. The safe management of nuclear waste and used nuclear fuel is a widespread, well-demonstrated reality. This strong safety record reflects a high degree of nuclear industry expertise and of industry responsibility toward the well-being of current and future generations

Chemistry for the nuclear energy of the future

International Nuclear Information System (INIS)

Chmielewski, A.G.

2011-01-01

Chemistry - radiochemistry, radiation chemistry and nuclear chemical engineering play a very important role in the nuclear power development. Even at present, the offered technology is well developed, but still several improvements are needed and proposed. These developments concern all stages of the technology; front end, reactor operation (coolant chemistry and installation components decontamination, noble gas release control), back end of fuel cycle, etc. Chemistry for a partitioning and a transmutation is a new challenge for the chemists and chemical engineers. The IV th generation of nuclear reactors cannot be developed without chemical solutions for fuel fabrication, radiation-coolants interaction phenomena understanding and spent fuel/waste treatment technologies elaboration. Radiochemical analytical methods are fundamental for radioecological monitoring of radioisotopes of natural and anthropological origin. This paper addresses just a few subjects and is not a detailed overview of the field, however it illustrates a role of chemistry for a safe and economical nuclear power development. (author)

Quantitative assessment of the environmental footprint of the French nuclear fuel cycle by life cycle assessment

International Nuclear Information System (INIS)

Poinssot, Christophe; Bourg, Stephane; Ouvrier, Noel; Serp, Jerome

2015-07-01

Full text of publication follows: Nuclear energy contributes to most than 75% of the French electricity thanks to the operation of 58 generation 2 reactors located on 19 sites built from the 70's to the end of the 90's. France also developed for a long time a fully integrated nuclear industry covering the whole nuclear fuel cycle, from the ore mining to the fabrication of the fuel for the front-end, from the reprocessing up to the MOX fuel fabrication and storage facility and in the near-future geological repository for the back-end. This investment allows France to produce a low-carbon electricity with the second lowest GHG emissions intensity, in the range of 90 g CO 2 /KWh. Such a very beneficial figure is directly related to the high contribution of nuclear in the electricity mix combined with renewables energies, in particular hydro. Greenhouse gases emissions are very relevant to assess the respective influence on the global climate change, but they do not address the whole potential environmental impact of any activity. However, such a question is crucial for assessing the respective sustainability of such an activity, in particular nuclear energy which is thought to be very detrimental by a large part of the public opinion. In order to address this question, we developed a dedicated life cycle assessment (LCA) tools referred to as NELCAS, the specificity of which is to focus on the first order parameters and avoiding any 'black-box' effect which can exist in commercial LCA tool. Thanks to the recent transparency and nuclear safety law (2006), in- and out- fluxes of matter and energy for any of the fuel cycle facilities are now publicly available. We hence used this significant set of measured data to feed our model and assess the most usual environmental indicators such as land use, different types of atmospheric emissions (GHG, SOx, NOx, particles...) and aqueous release (chemical effluents, eutrophication potential,...)... We also

Nuclear fuels

International Nuclear Information System (INIS)

2008-01-01

The nuclear fuel is one of the key component of a nuclear reactor. Inside it, the fission reactions of heavy atoms, uranium and plutonium, take place. It is located in the core of the reactor, but also in the core of the whole nuclear system. Its design and properties influence the behaviour, the efficiency and the safety of the reactor. Even if it represents a weak share of the generated electricity cost, its proper use represents an important economic stake. Important improvements remain to be made to increase its residence time inside the reactor, to supply more energy, and to improve its robustness. Beyond the economical and safety considerations, strategical questions have to find an answer, like the use of plutonium, the management of resources and the management of nuclear wastes and real technological challenges have to be taken up. This monograph summarizes the existing knowledge about the nuclear fuel, its behaviour inside the reactor, its limits of use, and its R and D tracks. It illustrates also the researches in progress and presents some key results obtained recently. Content: 1 - Introduction; 2 - The fuel of water-cooled reactors: aspect, fabrication, behaviour of UO 2 and MOX fuels inside the reactor, behaviour in loss of tightness situation, microscopic morphology of fuel ceramics and evolution under irradiation - migration and localisation of fission products in UOX and MOX matrices, modeling of fuels behaviour - modeling of defects and fission products in the UO 2 ceramics by ab initio calculations, cladding and assembly materials, pellet-cladding interaction, advanced UO 2 and MOX ceramics, mechanical behaviour of the fuel assembly, fuel during a loss of coolant accident, fuel during a reactivity accident, fuel during a serious accident, fuel management inside reactor cores, fuel cycle materials balance, long-term behaviour of the spent fuel, fuel of boiling water reactors; 3 - the fuel of liquid metal fast reactors: fast neutrons radiation

Thorium fuel cycle - Potential benefits and challenges

International Nuclear Information System (INIS)

2005-05-01

There has been significant interest among Member States in developing advanced and innovative technologies for safe, proliferation resistant and economically efficient nuclear fuel cycles, while minimizing waste and environmental impacts. This publication provides an insight into the reasons for renewed interest in the thorium fuel cycle, different implementation scenarios and options for the thorium cycle and an update of the information base on thorium fuels and fuel cycles. The present TECDOC focuses on the upcoming thorium based reactors, current information base, front and back end issues, including manufacturing and reprocessing of thorium fuels and waste management, proliferation-resistance and economic issues. The concluding chapter summarizes future prospects and recommendations pertaining to thorium fuels and fuel cycles

Analytical chemistry needs for nuclear safeguards in nuclear fuel reprocessing

International Nuclear Information System (INIS)

Hakkila, E.A.

1977-01-01

A fuel reprocessing plant designed to process 1500 tons of light water reactor fuel per year will recover 15 tons of Pu during that time, or approximately 40 to 50 kg of Pu per day. Conventional nuclear safeguards accountability has relied on batch accounting at the head and tail ends of the reprocessing plant with semi-annual plant cleanout to determine in-process holdup. An alternative proposed safeguards system relies on dynamic material accounting whereby in-line NDA and conventional analytical techniques provide indications on a daily basis of SNM transfers into the system and information of Pu holdup within the system. Some of the analytical requirements and problems for dynamic materials accounting in a nuclear fuel reprocessing plant are described. Some suggestions for further development will be proposed

Innovative nuclear fuels: results and strategy

International Nuclear Information System (INIS)

Stan, Marius

2009-01-01

To facilitate the discovery and design of innovative nuclear fuels, multi-scale models and simulations are used to predict irradiation effects on the thermal conductivity, oxygen diffusivity, and thermal expansion of oxide fuels. The multi-scale approach is illustrated using results on ceramic fuels with a focus on predictions of point defect concentrations, stoichiometry, and phase stability. The high performance computer simulations include coupled heat transport, diffusion, and thermal expansion, gas bubble formation and temperature evolution in a fuel element consisting of UO2 fuel and metallic cladding. The second part of the talk is dedicated to a discussion of an international strategy for developing advanced, innovative nuclear fuels. Four initiative are proposed to accelerate the discovery and design of new materials: (a) Develop an international pool of experts, (b) Create Institutes for Materials Discovery and Design, (c) Create an International Knowledge base for experimental data, models (mathematical expressions), and simulations (codes) and (d) Organize international workshops and conference sessions. The paper ends with a discussion of existing and emerging international collaborations.

A 1.2-V CMOS front-end for LTE direct conversion SAW-less receiver

International Nuclear Information System (INIS)

Wang Riyan; Li Zhengping; Zhang Weifeng; Zeng Longyue; Huang Jiwei

2012-01-01

A CMOS RF front-end for the long-term evolution (LTE) direct conversion receiver is presented. With a low noise transconductance amplifier (LNA), current commutating passive mixer and transimpedance operational amplifier (TIA), the RF front-end structure enables high-integration, high linearity and simple frequency planning for LTE multi-band applications. Large variable gain is achieved using current-steering transconductance stages. A current commutating passive mixer with 25% duty-cycle LO improves gain, noise and linearity. A direct coupled current-input filter (DCF) is employed to suppress the out-of-band interferer. Fabricated in a 0.13-μm CMOS process, the RF front-end achieves a 45 dB conversion voltage gain, 2.7 dB NF, −7 dBm IIP3, and +60 dBm IIP2 with calibration from 2.3 to 2.7 GHz. The total RF front end with divider draws 40 mA from a single 1.2-V supply. (semiconductor integrated circuits)

Development of Welding and Instrumentation Technology for Nuclear Fuel Test Rod

International Nuclear Information System (INIS)

Joung, Chang Young; Ahn, Sung Ho; Heo, Sung Ho; Hong, Jin Tae; Kim, Ka Hye

2013-01-01

It is necessary to develop various types of welding, instrumentation and helium gas filling techniques that can conduct TIG spot welding exactly at a pin-hole of the end-cap on the nuclear fuel rod to fill up helium gas. The welding process is one of the most important among the instrumentation processes of the nuclear fuel test rod. To manufacture the nuclear fuel test rod, a precision welding system needs to be fabricated to develop various welding technologies of the fuel test rod jointing the various sensors and end-caps on a fuel cladding tube, which is charged with fuel pellets and component parts. We therefore designed and fabricated an orbital TIG welding system and a laser welding system. This paper describes not only some experiment results from weld tests for the parts of a nuclear fuel test rod, but also the contents for the instrumentation process of the dummy fuel test rod installed with the C-type T. C. A dummy nuclear fuel test rod was successfully fabricated with the welding and instrumentation technologies acquired with various tests. In the test results, the round welding has shown a good weldability at both the orbital TIG welding system and the fiber laser welding system. The spot welding to fill up helium gas has shown a good welding performance at a welding current of 30A, welding time of 0.4 sec and gap of 1 mm in a helium gas atmosphere. The soundness of the nuclear fuel test rod sealed by a mechanical sealing method was confirmed by helium leak tests and microstructural analyses

Development of Welding and Instrumentation Technology for Nuclear Fuel Test Rod

Energy Technology Data Exchange (ETDEWEB)

Joung, Chang Young; Ahn, Sung Ho; Heo, Sung Ho; Hong, Jin Tae; Kim, Ka Hye [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

It is necessary to develop various types of welding, instrumentation and helium gas filling techniques that can conduct TIG spot welding exactly at a pin-hole of the end-cap on the nuclear fuel rod to fill up helium gas. The welding process is one of the most important among the instrumentation processes of the nuclear fuel test rod. To manufacture the nuclear fuel test rod, a precision welding system needs to be fabricated to develop various welding technologies of the fuel test rod jointing the various sensors and end-caps on a fuel cladding tube, which is charged with fuel pellets and component parts. We therefore designed and fabricated an orbital TIG welding system and a laser welding system. This paper describes not only some experiment results from weld tests for the parts of a nuclear fuel test rod, but also the contents for the instrumentation process of the dummy fuel test rod installed with the C-type T. C. A dummy nuclear fuel test rod was successfully fabricated with the welding and instrumentation technologies acquired with various tests. In the test results, the round welding has shown a good weldability at both the orbital TIG welding system and the fiber laser welding system. The spot welding to fill up helium gas has shown a good welding performance at a welding current of 30A, welding time of 0.4 sec and gap of 1 mm in a helium gas atmosphere. The soundness of the nuclear fuel test rod sealed by a mechanical sealing method was confirmed by helium leak tests and microstructural analyses.

Romanian nuclear fuel program

International Nuclear Information System (INIS)

Budan, O.

1999-01-01

The paper presents and comments the policy adopted in Romania for the production of CANDU-6 nuclear fuel before and after 1990. The CANDU-6 nuclear fuel manufacturing started in Romania in December 1983. Neither AECL nor any Canadian nuclear fuel manufacturer were involved in the Romanian industrial nuclear fuel production before 1990. After January 1990, the new created Romanian Electricity Authority (RENEL) assumed the responsibility for the Romanian Nuclear Power Program. It was RENEL's decision to stop, in June 1990, the nuclear fuel production at the Institute for Nuclear Power Reactors (IRNE) Pitesti. This decision was justified by the Canadian specialists team findings, revealed during a general, but well enough technically founded analysis performed at IRNE in the spring of 1990. All fuel manufactured before June 1990 was quarantined as it was considered of suspect quality. By that time more than 31,000 fuel bundles had already been manufactured. This fuel was stored for subsequent assessment. The paper explains the reasons which provoked this decision. The paper also presents the strategy adopted by RENEL after 1990 regarding the Romanian Nuclear Fuel Program. After a complex program done by Romanian and Canadian partners, in November 1994, AECL issued a temporary certification for the Romanian nuclear fuel plant. During the demonstration manufacturing run, as an essential milestone for the qualification of the Romanian fuel supplier for CANDU-6 reactors, 202 fuel bundles were produced. Of these fuel bundles, 66 were part of the Cernavoda NGS Unit 1 first fuel load (the balance was supplied by Zircatec Precision Industries Inc. ZPI). The industrial nuclear fuel fabrication re-started in Romania in January 1995 under AECL's periodical monitoring. In December 1995, AECL issued a permanent certificate, stating the Romanian nuclear fuel plant as a qualified and authorised CANDU-6 fuel supplier. The re-loading of the Cernavoda NGS Unit 1 started in the middle

Web-based DAQ systems: connecting the user and electronics front-ends

International Nuclear Information System (INIS)

Lenzi, Thomas

2016-01-01

Web technologies are quickly evolving and are gaining in computational power and flexibility, allowing for a paradigm shift in the field of Data Acquisition (DAQ) systems design. Modern web browsers offer the possibility to create intricate user interfaces and are able to process and render complex data. Furthermore, new web standards such as WebSockets allow for fast real-time communication between the server and the user with minimal overhead. Those improvements make it possible to move the control and monitoring operations from the back-end servers directly to the user and to the front-end electronics, thus reducing the complexity of the data acquisition chain. Moreover, web-based DAQ systems offer greater flexibility, accessibility, and maintainability on the user side than traditional applications which often lack portability and ease of use. As proof of concept, we implemented a simplified DAQ system on a mid-range Spartan6 Field Programmable Gate Array (FPGA) development board coupled to a digital front-end readout chip. The system is connected to the Internet and can be accessed from any web browser. It is composed of custom code to control the front-end readout and of a dual soft-core Microblaze processor to communicate with the client.

Web-based DAQ systems: connecting the user and electronics front-ends

Science.gov (United States)

Lenzi, Thomas

2016-12-01

Web technologies are quickly evolving and are gaining in computational power and flexibility, allowing for a paradigm shift in the field of Data Acquisition (DAQ) systems design. Modern web browsers offer the possibility to create intricate user interfaces and are able to process and render complex data. Furthermore, new web standards such as WebSockets allow for fast real-time communication between the server and the user with minimal overhead. Those improvements make it possible to move the control and monitoring operations from the back-end servers directly to the user and to the front-end electronics, thus reducing the complexity of the data acquisition chain. Moreover, web-based DAQ systems offer greater flexibility, accessibility, and maintainability on the user side than traditional applications which often lack portability and ease of use. As proof of concept, we implemented a simplified DAQ system on a mid-range Spartan6 Field Programmable Gate Array (FPGA) development board coupled to a digital front-end readout chip. The system is connected to the Internet and can be accessed from any web browser. It is composed of custom code to control the front-end readout and of a dual soft-core Microblaze processor to communicate with the client.

Calibration method for direct conversion receiver front-ends

Directory of Open Access Journals (Sweden)

R. Müller

2008-05-01

Full Text Available Technology induced process tolerances in analog circuits cause device characteristics different from specification. For direct conversion receiver front-ends a system level calibration method is presented. The malfunctions of the devices are compensated by tuning dominant circuit parameters. Thereto optimization techniques are applied which use measurement values and special evaluation functions.

Nuclear fuel element

International Nuclear Information System (INIS)

1974-01-01

A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding, and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

Nuclear fuel element

International Nuclear Information System (INIS)

Thompson, J.R.; Rowland, T.C.

1976-01-01

A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting, fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

Modern design of a fast front-end computer

Science.gov (United States)

Šoštarić, Z.; Anic̈ić, D.; Sekolec, L.; Su, J.

1994-12-01

Front-end computers (FEC) at Paul Scherrer Institut provide access to accelerator CAMAC-based sensors and actuators by way of a local area network. In the scope of the new generation FEC project, a front-end is regarded as a collection of services. The functionality of one such service is described in terms of Yourdon's environment, behaviour, processor and task models. The computational model (software representation of the environment) of the service is defined separately, using the information model of the Shlaer-Mellor method, and Sather OO language. In parallel with the analysis and later with the design, a suite of test programmes was developed to evaluate the feasibility of different computing platforms for the project and a set of rapid prototypes was produced to resolve different implementation issues. The past and future aspects of the project and its driving forces are presented. Justification of the choice of methodology, platform and requirement, is given. We conclude with a description of the present state, priorities and limitations of our project.

FRONT-END ASIC FOR A SILICON COMPTON TELESCOPE.

Energy Technology Data Exchange (ETDEWEB)

DE GERONIMO,G.; FRIED, J.; FROST, E.; PHLIPS, B.; VERNON, E.; WULF, E.A.

2007-10-27

We describe a front-end application specific integrated circuit (ASIC) developed for a silicon Compton telescope. Composed of 32 channels, it reads out signals in both polarities from each side of a Silicon strip sensor, 2 mm thick 27 cm long, characterized by a strip capacitance of 30 pF. Each front-end channel provides low-noise charge amplification, shaping with a stabilized baseline, discrimination, and peak detection with an analog memory. The channels can process events simultaneously, and the read out is sparsified. The charge amplifier makes uses a dual-cascode configuration and dual-polarity adaptive reset, The low-hysteresis discriminator and the multi-phase peak detector process signals with a dynamic range in excess of four hundred. An equivalent noise charge (ENC) below 200 electrons was measured at 30 pF, with a slope of about 4.5 electrons/pF at a peaking time of 4 {micro}s. With a total dissipated power of 5 mW the channel covers an energy range up to 3.2 MeV.

Nuclear fuel assemblies and fuel pins usable in such assemblies

International Nuclear Information System (INIS)

Jolly, R.

1982-01-01

A novel end cap for a nuclear fuel assembly is described in detail. It consists of a trisection arrangement which is received within a cell of a cellular grid. The cell contains abutment means with which the trisection comes into abutment. The grid also contains an abutment means for preventing the trisections from being inserted into the cell in an incorrect orientation. The present design allows fuel pins to be securely held in a hold-down grid of a sub-assembly. The design also allows easier dis-assembly of the swollen and embrittled fuel pins prior to reprocessing. (U.K.)

General design of the layout for new undulator-only beamline front ends

International Nuclear Information System (INIS)

Shu Deming; Ramanathan, Mohan; Kuzay, Tuncer M.

2001-01-01

A great majority of the Advanced Photon Source (APS) users have chosen an undulator as the only source for their insertion device beamline. Compared with a wiggler source, the undulator source has a much smaller horizontal divergence, providing us with an opportunity to optimize the beamline front-end design further. In this paper, the particular designs and specifications, as well as the optical and bremsstrahlung ray-tracing analysis of the new APS front ends for undulator-only operation are presented

Nuclear-fuel-cycle education: Module 1. Nuclear fuel cycle overview

International Nuclear Information System (INIS)

Eckhoff, N.D.

1981-07-01

This educational module is an overview of the nuclear-fule-cycle. The overview covers nuclear energy resources, the present and future US nuclear industry, the industry view of nuclear power, the International Nuclear Fuel Cycle Evaluation program, the Union of Concerned Scientists view of the nuclear-fuel-cycle, an analysis of this viewpoint, resource requirements for a model light water reactor, and world nuclear power considerations

A socio-internactive framework for the fuzzy front end

NARCIS (Netherlands)

Smulders, Frido E.; van den Broek, Egon; van der Voort, Mascha C.; Fernandes, A.; Teixeira, A.; Natal Jorge, R.

2007-01-01

This paper aims to illustrate that the dominating rational-analytic perspective on the Fuzzy Front End (FFE) of innovation could benefit by a complementary socio-interactive perspective that addresses the social processes during the FFE. We have developed a still fledgling socio-interactive

Fuel for the next Brazilian nuclear power plants

International Nuclear Information System (INIS)

Lameiras, Fernando S.; Faeda, Kelly Cristina Ferreira

2009-01-01

The conclusion of the Angra III nuclear power plant ends a cycle of the nuclear energy in Brazil that started about forty years ago. Nowadays the country is planning the installation of 4 GWe to 8 GWe of nuclear power up to the year 2030. The nuclear reactors considered for this new cycle should take into account the current technologic development and environment of the nuclear market. They certainly will have significant differences in relation to the Angra I, II, and III reactors. Important impacts may result on the nuclear fuel production chain, e. g., case high temperature reactors were chosen, which can deliver electricity and heat. The differences between the fuels of the candidate reactors after Angra III are analyzed and development lines are suggested to minimize these impacts. (author)

Pressure loss coefficient and flow rate of side hole in a lower end plug for dual-cooled annular nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Shin, Chang-Hwan, E-mail: shinch@kaeri.re.kr; Park, Ju-Yong, E-mail: juyong@kaeri.re.kr; In, Wang-Kee, E-mail: wkin@kaeri.re.kr

2013-12-15

Highlights: • A lower end plug with side flow holes is suggested to provide alternative flow paths of the inner channel. • The inlet loss coefficient of the lower end plug is estimated from the experiment. • The flow rate through the side holes is estimated in a complete entrance blockage of inner channel. • The consequence in the reactor core condition is evaluated with a subchannel analysis code. - Abstract: Dual-cooled annular nuclear fuel for a pressurized water reactor (PWR) has been introduced for a significant increase in reactor power. KAERI has been developing a dual-cooled annular fuel for a power uprate of 20% in an optimized PWR in Korea, the OPR1000. This annular fuel can help decrease the fuel temperature substantially relative to conventional cylindrical fuel at a power uprate. Annular fuel has dual flow channels around itself; however, the inner flow channel has a weakness in that it is isolated unlike the outer flow channel, which is open to other neighbouring outer channels for a coolant exchange in the reactor core. If the entrance of the inner channel is, as a hypothetical event, completely blocked by debris, the inner channel will then experience a rapid increase in coolant temperature such that a departure from nucleate boiling (DNB) may occur. Therefore, a remedy to avoid such a postulated accident is indispensable for the safety of annular fuel. A lower end plug with side flow holes was suggested to provide alternative flow paths in addition to the central entrance of the inner channel. In this paper, the inlet loss coefficient of the lower end plug and the flow rate through the side holes were estimated from the experimental results even in a complete entrance blockage of the inner channel. An optimization for the side hole was also performed, and the results are applied to a subchannel analysis to evaluate the consequence in the reactor core condition.

Spent nuclear fuel structural response when subject to an end impact accident

Energy Technology Data Exchange (ETDEWEB)

Tang, D.T.; Guttmann, J. [United States Nuclear Regulatory Commission, Rockville, MD (United States)]|[United States Nuclear Regulatory Commission, Washington, DC (United States); Koeppel, B.J.; Adkins, H.E.

2004-07-01

The US Nuclear Regulatory Commission (USNRC) is responsible for licensing spent fuel storage and transportation systems. A subset of this responsibility is to investigate and understand the structural performance of these systems. Studies have shown that the fuel rods of intact spent fuel assemblies with burn-ups up to 45 gigawatt days per metric ton of uranium (Gwd/MTU) are capable of resisting the normally expected impact loads subjected during drop accident conditions. However, effective cladding thickness for intact spent fuel assemblies with burn ups greater than 45 Gwd/MTU can be reduced due to corrosion. The capability of the fuel rod to withstand the expected loads encountered under normal and accident conditions may also be reduced, given degradation of the material properties under extended use, such as decrease in ductility. The USNRC and Pacific Northwest Laboratory (PNNL) performed computational studies to predict the structural response of spent nuclear fuel in a transport system that is subjected to a hypothetical regulatory impact accident, as defined in 10 CFR71.73. This study performs a structural analysis of a typical high burn up Pressurized Water Reactor (PWR) fuel assembly using the ANSYS {sup registered} ANSYS {sup registered} /LS- DYNA {sup registered} finite element analysis (FEA) code. The material properties used in the analyses were based on expert judgment and included uncertainties. Ongoing experimental programs will reduce the uncertainties. The current evaluations include the pins, spacer grids, and tie plates to assess possible cladding failure/rupture under hypothetical impact accident loading. This paper describes the USNRC and PNNL staff's analytical approach, provides details on the single pin model developed for this assessment, and presents the results.

Verification of the Barnwell Nuclear Fuel Plant (BNFP) mechanical headend design

International Nuclear Information System (INIS)

Townes, G.A.

1978-11-01

Design of the Barnwell Nuclear Fuel Plant mechanical head end includes unique provisions for remote maintenance, minimizes remote handling, and permits high throughput (6 MTU of spent fuel per day). Operability studies have been performed under a contract with the Department of Energy that: (1) assessed its capabilities for possible use in fuel encapsulation with or without compaction as a preparation for spent fuel storage, (2) verified the design of the mechanical head end as remotely maintainable, and (3) provided operator training

Nuclear fuel assembly incorporating primary and secondary structural support members

International Nuclear Information System (INIS)

Carlson, W.R.; Gjertsen, R.K.; Miller, J.V.

1987-01-01

A nuclear fuel assembly, comprising: (a) an upper end structure; (b) a lower end structure; (c) elongated primary structural members extending longitudinally between and rigidly interconnecting the upper and lower end structures, the upper and lower end structures and primary structural members together forming a rigid structural skeleton of the fuel assembly; (d) transverse grids supported on the primary structural members at axially spaced locations therealong between the upper and lower end structures; (e) fuel rods extending through and supported by the grids between the upper and lower end structures so as to extend in generally side-by-side spaced relation to one another and to the primary structural members; and (f) elongated secondary structural members extending longitudinally between but unconnected with the upper and lower end structures, the secondary structural members extending through and rigidly interconnected with the grids to extend in generally side-by-side spaced relation to one another, to the fuel rods and to the primary structural members so as to bolster the stiffness of the structural skeleton of the fuel assembly

Domestic nuclear fuels supply: possibility of an independent technology

International Nuclear Information System (INIS)

Cirimello, R.O.

1982-01-01

After considering the different energy sources, their consumption and their respective periods of exploitation, technological considerations in the nuclear fuel field are made. The main subject is the Domestic Supply Project of Embalse Fuel (CANDU type). The different aspects which had to be developed during the realization of this project still under progress, and which are fundamental for the command of the technology, are described: 1) Qualification of the produced fuel elements: fuel elements' characteristics; the reactors' operating parameters, and the prototype fuel elements' characteristics; 2) Development of materials and/or suppliers: the obtainment of UO 2 and its physical properties are considered, as well as those of Zircaloy-4, the development of suppliers and the respective developments for the obtainment of materials such as beryllium, helium and colloidal graphite; 3) Processes development; the following processes are studied and defined: UO 2 pellets fabrication with UO 2 granulated powder; beryllium coating under vaccum; and induction brazing of bearing pads and spacers, end cap and end plate resistance welding and stamping of Zircaloy components, graphite-coating of cladding's internal face; 4) Development of special production equipments; automatic equipment for end cap-to-cladding resistance welding among others. The need for a specific program of quality assurance for nuclear fuels supply is emphasized and the basic criteria are established. The IAEA's quality asssurance requirements are also analyzed. (M.E.L.) [es

Analysis of fuel end-temperature peaking

Energy Technology Data Exchange (ETDEWEB)

Xu, Z.; Jiang, Q.; Lai, L.; Shams, M. [CANDU Energy Inc., Fuel Engineering Dept., Mississauga, Ontario (Canada)

2013-07-01

During normal operation and refuelling of CANDU® fuel, fuel temperatures near bundle ends will increase due to a phenomenon called end flux peaking. Similar phenomenon would also be expected to occur during a postulated large break LOCA event. The end flux peaking in a CANDU fuel element is due to the fact that neutron flux is higher near a bundle end, in contact with a neighbouring bundle or close to heavy water coolant, than in the bundle mid-plane, because of less absorption of thermal neutrons by Zircaloy or heavy water than by the UO{sub 2} material. This paper describes Candu Energy experience in analysing behaviour of bundle due to end flux peaking using fuel codes FEAT, ELESTRES and ELOCA. (author)

Progress with the SNS front-end systems

International Nuclear Information System (INIS)

Keller, R.; Abraham, W.; Ayers, J.J.; Cheng, D.W.; Cull, P.; DiGennaro, R.; Doolittle, L.; Gough, R.A.; Greer, J.B.; Hoff, M.D.; Leung, K.N.; Lewis, S.; Lionberger, C.; MacGill, R.; Minamihara, Y.; Monroy, M.; Oshatz, D.; Pruyn, J.; Ratti, A.; Reijonen, J.; Schenkel, T.; Staples, J.W.; Syversrud, D.; Thomae, R.; Virostek, S.; Yourd, R.

2001-01-01

The Front-End Systems (FES) of the Spallation Neutron Source (SNS) project have been described in detail elsewhere [1]. They comprise an rf-driven H - ion source, electrostatic LEBT, four-vane RFQ, and an elaborate MEBT. These systems are planned to be delivered to the SNS facility in Oak Ridge in June 2002. This paper discusses the latest design features, the status of development work, component fabrication and procurements, and experimental results with the first commissioned beamline elements

The Contribution of Innovation Strategy Development and Implementation in Active Facilitation of Pharmaceutical Front End Innovation

DEFF Research Database (Denmark)

Aagaard, Annabeth

2012-01-01

Front end innovation (FEI) represents the first building blocks of product development, but is often regarded as a weak link in innovation literature. Various theorists emphasize that a firm’s innovation can benefit substantially by improving the front end of innovation process (Reinertsen, 1999,......-oriented longitudinal case study of a Danish pharmaceutical company. The findings and key learnings from the study are presented as propositions of how innovation strategies can be applied to actively facilitate FEI and with measurable results.......Front end innovation (FEI) represents the first building blocks of product development, but is often regarded as a weak link in innovation literature. Various theorists emphasize that a firm’s innovation can benefit substantially by improving the front end of innovation process (Reinertsen, 1999...

Tuned Optical Front-End MMIC Amplifiers for a Coherent Optical Receiver

DEFF Research Database (Denmark)

Petersen, Anders Kongstad; Jagd, A M

1992-01-01

Two low noise tuned optical front-end GaAs MESFET MMIC amplifiers for a coherent optical CPFSK (Continuous Phase Frequency Shift Keying) receiver are presented. The receiver operates at 2.5 Gbit/s at an IF of approx. 9 GHz. The front-ends are based on full-custom designed MMICs and a commercially...... available GaInAs/InP pin photo diode. The procedure for measuring the transimpedance and the equivalent input noise current density is outlined in this paper and demonstrated using one of the MMICs. The MMICs were fabricated using the Plessey F20 process by GEC-Marconi through the ESPRIT programme EUROCHIP...

Hybrid circuit prototypes for the CMS Tracker upgrade front-end electronics

International Nuclear Information System (INIS)

Blanchot, G; Honma, A; Kovacs, M; Braga, D; Raymond, M

2013-01-01

New high-density interconnect hybrid circuits are under development for the CMS tracker modules at the HL-LHC. These hybrids will provide module connectivity between flip-chip front-end ASICs, strip sensors and a service board for the data transmission and powering. Rigid organic-based substrate prototypes and also a flexible hybrid design have been built, containing up to eight front-end flip chip ASICs. A description of the function of the hybrid circuit in the tracker, the first prototype designs, results of some electrical and mechanical properties from the prototypes, and examples of the integration of the hybrids into detector modules are presented

Resource Conservation and Recovery Act (RCRA) Characterization of Spent Nuclear Fuel

International Nuclear Information System (INIS)

Nichols, D.M.

1998-01-01

As a result of the end of the Cold War and the Nonproliferation treaty, the United States is left with quantifies of spent nuclear fuel. The final disposition of the spent nuclear fuel is yet to be determined. However, one issue that plagues the holders of this material is 'if this material is no longer required and must be disposed, how will it be classified under current U.S. environmental laws and regulations?' This paper provides one site's position on the characterization of the spent nuclear fuel as a non-hazardous solid waste

VME as a front-end electronics system in high energy physics experiments

International Nuclear Information System (INIS)

Ohska, T.K.

1990-01-01

It is only a few years since the VME became a standard system, yet the VME system is already so much more popular than other systems. The VME system was developed for industrial applications and not for the scientific research, and high energy physics field is a tiny market when compared with the industrial market. Considerations made here indicate that the VME system would be a good one for a rear-end system, but would not be a good candidate for front-end electronics in physics experiments. Furthermore, there is a fear that the VXI bus could become popular in this field of instrumentation since the VXI system is backed up by major suppliers of instrumentation in the high energy physics field. VXI would not be an adequate system for front-end electronics, yet advertised to be one. It would be worse to see the VXI system to become a standard system for high energy physics instrumentation than the VME system to be one. The VXI system would do a mediocre job so that people might be misled to think that the VXI system can be used as front-end system. (N.K.)

The present Swedish nuclear fuel and waste position in perspective

International Nuclear Information System (INIS)

Svenke, E.

1983-01-01

In Sweden current efforts are focussed on research and development of the management of all types of radioactive residues and on industrial projects for the implementation of a complete programme for the back-end of the fuel cycle, where, in fact, international commercial services scarcely exist. Another reason for this priority is the need to allay public anxiety on the subject. The paper describes the policy, planning, and development of the Swedish nuclear back-end as well as its organization and financing. In Sweden the licensee of a nuclear power facility assumes direct responsibility, technically and financially, for the nuclear waste he generates. To cover future costs with respect to the back-end, the utilities pay to the State a fee related to their production of nuclear electricity. The fee is kept in a fund administered by the State through an authority, the 'National Board for Spent Nuclear Fuel'. The technical implementation programme comprises a sea transportation system to be operational by the end of 1982 and a central facility for intermediate storage of spent reactor fuel to be operational by 1985. The third step in the Swedish waste programme is a central final storage facility for reactor wastes other than spent fuel (planned to be in operation by 1988). Broad research and development work is going on in a deep underground system for the isolation of highly active and long-lived wastes. A rock drilling programme is being carried out at several places and is planned to continue for a period of approximately ten years. Encapsulation of waste and the properties of buffer materials are being studied. The paper stresses the importance of achieving generally and multi-nationally accepted guidelines for waste isolation systems and also of proper demonstration of the performance of the various parts of such systems

Utilities' view on the fuel management of nuclear power plants

International Nuclear Information System (INIS)

Held, C.; Moraw, G.; Schneeberger, M.; Szeless, A.

1977-01-01

Utilities engagement in nuclear power requires an increasing amount of fuel management activities by the utilities in order to meet all tasks involved. These activities comprise essentially two main areas: - activities to secure the procurement of all steps of the fuel cycle from the head to the back end; - activities related to the incore fuel managment. A general survey of the different steps of the nuclear fuel cycle is presented together with the related activities and responsibilities which have to be realized by the utilities. Starting in the past, today's increasing utility involvement in the nuclear fuel management is shown, as well as future fuel management trends. The scope of utilities' fuel management activities is analyzed with respect to organizational aspects, technical aspects, safeguarding aspects, and financial aspects. Utilities taking active part in the fuel management serves to achieve high availability and flexibility of the nuclear power plant during the whole plant life as well as safe waste isolation. This can be assured by continuous optimization of all fuel management aspects of the power plant or on a larger scale of a power plant system, i.e., utility activities to minimize the effects of fuel cycle on the environment, which includes optimization of fuel behaviour, radiation exposure to public and personnel, and utility technical and economic evaluations of out- and incore fuel management. These activities of nuclear power producing utilities in the field of nuclear fuel cycle are together with a close cooperation with fuel industry as well as national and international authorities a necessary basis for the further utilization of nuclear power

Commissioning and Operation of the FNAL Front end Injection Line and Ion Sources.

Energy Technology Data Exchange (ETDEWEB)

Karns, Patrick R. [Indiana Univ., Bloomington, IN (United States)

2015-09-01

This thesis documents the efforts made in commissioning and operating the RFQ Injection Line (RIL) as a replacement for the Cockcroft Walton front end. The Low Energy Beam Transport (LEBT) was assembled and tested with multiwire position and emittance monitor measurements. The Radio Frequency Quadrupole (RFQ) commissioning was completed with the same measurements as well as output beam energy measurements that showed it initially accelerated beam only to 700 keV, which was 50 keV lower than the design energy. Working with the manufacturer solutions were found and instituted to continue testing. The Medium Energy Beam Transport (MEBT) was then connected as the RIL was installed as the new front end of Linac. Testing gave way to operation when the new front end was used as the source of all High Energy Physics (HEP) beam for Fermi National Accelerator Laboratory (FNAL). The magnetron ion source that provides the H- beam for the front end required several changes and eventual upgrades to operate well; such as new source operating points for vacuum pressure and cesium admixture, and new materials for critical source components. Further research was conducted on the cathode geometry and nitrogen doping of the hydrogen gas as well as using solid state switches for the extractor system high voltage.

InP DHBT MMICs for millimeter-wave front-ends

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Hadziabdic, Dzenan; Krozer, Viktor

2009-01-01

In this paper, we show advanced MMIC's using InP DHBT technology. In particular, we demonstrate front-end circuits covering a broad frequency range from Q-band to E-band. Realizations of power amplifiers, quadrature VCOs, and sub-harmonic mixers, are presented and experimental results are discussed....

The DIALOG Chip in the Front-End Electronics of the LHCb Muon Detector

CERN Document Server

Cadeddu, S; Lai, A

2004-01-01

We present a custom integrated circuit, named DIALOG, which is a fundamental building block in the front-end architecture of the LHCb Muon detector. DIALOG is realized in IBM 0.25 um technology, using radiation hardening layout techniques. DIALOG integrates important tools for detector time alignment procedures and time alignment monitoring on the front- end system. In particular, it integrates 16 programmable delays, which can be regulated in steps of 1 ns. Many other features, necessary for the Muon trigger operation and for a safe front-end monitoring are integrated: DIALOG generates the information used by the trigger as a combination of its 16 inputs from the Amplifier-Shaper-Discriminator (ASD) chips, it generates the thresholds of the ASD, it monitors the rate of all its input channels. We describe the circuit architecture, its internal blocks and its main modes of operation.

Single-current-sensor-based active front-end-converter-fed four ...

Indian Academy of Sciences (India)

Joseph Kiran Banda

Keywords. Field-oriented control; vector control of induction motor; active front end converter; power factor correction .... sinusoidal three-phase input currents applied to the stator. ... with necessary feed-forward terms are employed to control.

Control of SiC Based Front-End Rectifier under Unbalanced Supply Voltage

DEFF Research Database (Denmark)

Maheshwari, Ramkrishan; Trintis, Ionut; Gohil, Ghanshyamsinh Vijaysinh

2015-01-01

A voltage source converter is used as a front end converter typically. In this paper, a converter which is realized using SiC MOSFET is considered. Due to SiC MOSFET, a switching frequency more than 50 kHz can be achieved. This can help increasing the current control loop bandwidth, which is not ...... together with a positive-sequence current controller for the front-end rectifier. A gain in the feedforward term can be changed to control the negative-sequence current. Simulation results are presented to verify the theory....

Modified ADS molten salt processes for back-end fuel cycle of PWR spent fuel

International Nuclear Information System (INIS)

Choi, In-Kyu; Yeon, Jei-Won; Kim, Won-Ho

2002-01-01

The back-end fuel cycle concept for PWR spent fuel is explained. This concept is adequate for Korea, which has operated both PWR and CANDU reactors. Molten salt processes for accelerator driven system (ADS) were modified both for the transmutation of long-lived radioisotopes and for the utilisation of the remained fissile uranium in PWR spent fuels. Prior to applying molten salt processes to PWR fuel, hydrofluorination and fluorination processes are applied to obtain uranium hexafluoride from the spent fuel pellet. It is converted to uranium dioxide and fabricated into CANDU fuel. From the remained fluoride compounds, transuranium elements can be separated by the molten salt technology such as electrowinning and reductive extraction processes for transmutation purpose without weakening the proliferation resistance of molten salt technology. The proposed fuel cycle concept using fluorination processes is thought to be adequate for our nuclear program and can replace DUPIC (Direct Use of spent PWR fuel in CANDU reactor) fuel cycle. Each process for the proposed fuel cycle concept was evaluated in detail

Review of the patents of Top and Bottom End Piece and fuel materials issued by overseas fuel vendors