Long-term heat storage in calcium sulfoaluminate cement (CSA) based concrete

Energy Technology Data Exchange (ETDEWEB)

Kaufmann, Josef P.; Winnefeld, Frank [Empa Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland). Lab. for Concrete and Construction Chemistry

2011-07-01

In general, the selection of materials proposed for solar heat storage is based on one of two principal processes: sensible heat storage or latent heat storage. Sensible heat storage utilizes the specific heat capacity of a material, while latent heat storage is based on the change in enthalpy (heat content) associated with a phase change of the material. Long time sensible heat storage requires excellent thermal insulation whereas latent heat storage allows permanent (seasonal) storage without significant energy losses and any special insulation. Ettringite, one of the cement hydration products, exhibits a high dehydration enthalpy. Calcium sulfoaluminate cement based concrete containing a high amount of ettringite is henceproposed as an efficient latent heat storage material. Compared to conventional heat storage materials this innovative concrete mixture has a high loss-free storage energy density (> 100-150 kWh/m{sup 3}) which is much higher than the one of paraffin or the (loss-sensitive) sensible heat of water. Like common concrete the CSA-concrete is stable and even may carry loads. The dehydration of the CSA-concrete is achieved at temperatures below 100 C. The rehydration process occurs as soon as water (liquid or vapor) is added. In contrast to paraffin, the phase change temperature is not fixed and the latent heat may be recovered at any desired temperature. Furthermore the heat conductivity of this material is high, so that the energy transfer from/to an exchange medium is easy. Additionally CSA-concrete is not flammable and absolutely safe regarding any health aspects. The cost of such CSA-concrete isin the order of normal concrete. The main application is seen in house heating systems. Solar heat, mostly generated during the summer period by means of roof collectors, can be stored in CSA-concrete until the winter. A part or even the whole annual heatingenergy may be produced and saved locally by the householder himself. Additional applications may be

Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

Long-term cryogenic space storage system

Science.gov (United States)

Hopkins, R. A.; Chronic, W. L.

1973-01-01

Discussion of the design, fabrication and testing of a 225-cu ft spherical cryogenic storage system for long-term subcritical applications under zero-g conditions in storing subcritical cryogens for space vehicle propulsion systems. The insulation system design, the analytical methods used, and the correlation between the performance test results and analytical predictions are described. The best available multilayer insulation materials and state-of-the-art thermal protection concepts were applied in the design, providing a boiloff rate of 0.152 lb/hr, or 0.032% per day, and an overall heat flux of 0.066 Btu/sq ft hr based on a 200 sq ft surface area. A six to eighteen month cryogenic storage is provided by this system for space applications.

Modelling the long-term deployment of electricity storage in the global energy system

International Nuclear Information System (INIS)

Despres, Jacques

2015-01-01

The current development of wind and solar power sources calls for an improvement of long-term energy models. Indeed, high shares of variable wind and solar productions have short- and long-term impacts on the power system, requiring the development of flexibility options: fast-reacting power plants, demand response, grid enhancement or electricity storage. Our first main contribution is the modelling of electricity storage and grid expansion in the POLES model (Prospective Outlook on Long-term Energy Systems). We set up new investment mechanisms, where storage development is based on several combined economic values. After categorising the long-term energy models and the power sector modelling tools in a common typology, we showed the need for a better integration of both approaches. Therefore, the second major contribution of our work is the yearly coupling of POLES to a short-term optimisation of the power sector operation, with the European Unit Commitment and Dispatch model (EUCAD). The two-way data exchange allows the long-term coherent scenarios of POLES to be directly backed by the short-term technical detail of EUCAD. Our results forecast a strong and rather quick development of the cheapest flexibility options: grid interconnections, pumped hydro storage and demand response programs, including electric vehicle charging optimisation and vehicle-to-grid storage. The more expensive battery storage presumably finds enough system value in the second half of the century. A sensitivity analysis shows that improving the fixed costs of batteries impacts more the investments than improving their efficiency. We also show the explicit dependency between storage and variable renewable energy sources. (author) [fr

Long-term data storage in diamond

OpenAIRE

Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A.

2016-01-01

The negatively charged nitrogen vacancy (NV?) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV? optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multic...

Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

Pyrophoricity of uranium in long-term storage environments

International Nuclear Information System (INIS)

Solbrig, C.W.; Krsul, J.R.; Olsen, D.N.

1994-01-01

A corrosion cycle for uranium is postulated which can be used to assess whether a given storage situation might produce fire hazards and/or continual uranium corrosion. A significant reaction rate of uranium and moisture occurs at room temperature which produces uranium oxide and hydrogen. If the hydrogen cannot escape, it will react slowly with uranium to form uranium hydride. The hydride is pyrophoric at room temperature when exposed to air. Either the hydrogen or the hydride can produce a dangerous situation as demonstrated by two different incidents described here. Long-term corrosion will occur even if the normal precautions are taken as is demonstrated by the long-term storage of stainless steel clad uranium fuel plates. The major initiator of these problems is attributed to any moisture condensed on the metal or any brought in by the cover gas. The postulated corrosion cycle is used to suggest ways to circumvent these problems

Long-term stable surface modification of DLC coatings

Directory of Open Access Journals (Sweden)

Gotzmann Gaby

2017-09-01

Full Text Available The use of coatings based on diamond like carbon (DLC for medical applications was established during the last years. Main advantages of these coatings are its high hardness, good wear and friction behavior and its biocompatibility. Using low-energy electron-beam treatment, we addressed the surface modification of DLC coatings. The aim was to generate new biofunctional surface characteristics that are long-term stable.

Assessment of spent WWER-440 fuel performance under long-term storage conditions

Energy Technology Data Exchange (ETDEWEB)

Kupca, L [VUJE Inc. (Slovakia)

2012-07-01

In the Slovak Republic are under operation 6 units (4 in the Jaslovske Bohunice site, and 2 in the Mochovce), 2 units are under construction in Mochovce site. All units are WWER-440 type. The fresh fuel is imported from the Russian Federation. The spent fuel assemblies are stored in wet conditions in Bohunice Interim Storage Spent Fuel Facility (SFIS). By 15 July 2008, there were 8413 assemblies in SFIS. The objectives are: 1) Wet AR storage of spent fuel from the NPP Bohunice and Mochovce: Surveillance of conditions for spent fuel storage in the at-reactor (AR) storage pools of both NPP's (characteristics of pool water, corrosion product data); Visual control of storage pool components; Evaluation of storage conditions with respect to long-term stability (corrosion of fuel cladding, structural materials); 2) Wet SFIS storage at Bohunice: Measurement of spent fuel conditions during the long-term wet storage, activity data in the storage casks and amount of crud; Surveillance program for SFIS structural materials.

Effect of long-term storage of LWR spent fuel on Pu-thermal fuel cycle

International Nuclear Information System (INIS)

Kurosawa, Masayoshi; Naito, Yoshitaka; Suyama, Kenya; Itahara, Kuniyuki; Suzuki, Katsuo; Hamada, Koji

1998-01-01

According to the Long-term Program for Research, Development and Utilization of Nuclear Energy (June, 1994) in Japan, the Rokkasho Reprocessing Plant will be operated shortly after the year 2000, and the planning of the construction of the second commercial plant will be decided around 2010. Also, it is described that spent fuel storage has a positive meaning as an energy resource for the future utilization of Pu. Considering the balance between the increase of spent fuels and the domestic reprocessing capacity in Japan, it can be expected that the long-term storage of UO 2 spent fuels will be required. Then, we studied the effect of long-term storage of spent fuels on Pu-thermal fuel cycle. The burnup calculation were performed on the typical Japanese PWR fuel, and the burnup and criticality calculations were carried out on the Pu-thermal cores with MOX fuel. Based on the results, we evaluate the influence of extending the spent fuel storage term on the criticality safety, shielding design of the reprocessing plant and the core life time of the MOX core, etc. As the result of this work on long-term storage of LWR spent fuels, it becomes clear that there are few demerits regarding the lifetime of a MOX reactor core, and that there are many merits regarding the safety aspects of the fuel cycle facilities. Furthermore, long-term storage is meaningful as energy storage for effective utilization of Pu to be improved by technological innovation in future, and it will allow for sufficient time for the important policymaking of nuclear fuel cycle establishment in Japan. (author)

Long-term data storage in diamond

Science.gov (United States)

Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A.

2016-01-01

The negatively charged nitrogen vacancy (NV−) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV− optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multicolor optical microscopy to read, write, and reset arbitrary data sets with two-dimensional (2D) binary bit density comparable to present digital-video-disk (DVD) technology. Leveraging on the singular dynamics of NV− ionization, we encode information on different planes of the diamond crystal with no cross-talk, hence extending the storage capacity to three dimensions. Furthermore, we correlate the center’s charge state and the nuclear spin polarization of the nitrogen host and show that the latter is robust to a cycle of NV− ionization and recharge. In combination with super-resolution microscopy techniques, these observations provide a route toward subdiffraction NV charge control, a regime where the storage capacity could exceed present technologies. PMID:27819045

Long-term data storage in diamond.

Science.gov (United States)

Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A

2016-10-01

The negatively charged nitrogen vacancy (NV - ) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV - optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multicolor optical microscopy to read, write, and reset arbitrary data sets with two-dimensional (2D) binary bit density comparable to present digital-video-disk (DVD) technology. Leveraging on the singular dynamics of NV - ionization, we encode information on different planes of the diamond crystal with no cross-talk, hence extending the storage capacity to three dimensions. Furthermore, we correlate the center's charge state and the nuclear spin polarization of the nitrogen host and show that the latter is robust to a cycle of NV - ionization and recharge. In combination with super-resolution microscopy techniques, these observations provide a route toward subdiffraction NV charge control, a regime where the storage capacity could exceed present technologies.

Assessment of spent WWER-440 fuel performance under long-term storage conditions

Energy Technology Data Exchange (ETDEWEB)

Takats, F [TS Enercon Kft. (Hungary)

2012-07-01

Paks Nuclear Power Plant is the only NPP in Hungary. It has four WWER-440 type reactor units. The fresh fuel is imported from Russia so far. The spent fuel assemblies were shipped back to Russia until 1997 after about 6 years cooling at the plant. A dry storage facility (MVDS type) has been constructed and is operational since then. By 1 January 2008, there were 5107 assemblies in dry storage. The objectives are: 1) Wet AR storage of spent fuel from the NPP Paks: Measurements of conditions for spent fuel storage in the at-reactor (AR) storage pools of Paks NPP (physical and chemical characteristics of pool water, corrosion product data); Measurements and visual control of storage pool component characteristics; Evaluation of storage characteristics and conditions with respect to long-term stability (corrosion of fuel cladding, construction materials); 2) Dry AFR storage at Paks NPP: Calculation and measurement of spent fuel conditions during the transfer from the storage pool to the modular vault dry storage (MVDS) on the site; Calculation and measurement of spent fuel conditions during the preparation of fuel for dry storage (drying process), such as crud release, activity build-up; Measurement of spent fuel conditions during the long-term dry storage, activity data in the storage tubes and amount of crud.

Long-term fertilization alters chemically-separated soil organic carbon pools: Based on stable C isotope analyses

Science.gov (United States)

Dou, Xiaolin; He, Ping; Cheng, Xiaoli; Zhou, Wei

2016-01-01

Quantification of dynamics of soil organic carbon (SOC) pools under the influence of long-term fertilization is essential for predicting carbon (C) sequestration. We combined soil chemical fractionation with stable C isotope analyses to investigate the C dynamics of the various SOC pools after 25 years of fertilization. Five types of soil samples (0-20, 20-40 cm) including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, IN; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into recalcitrant and labile fractions, and the fractions were analysed for C content, C:N ratios, δ13C values, soil C and N recalcitrance indexes (RIC and RIN). Chemical fractionation showed long-term MNPK fertilization strongly increased the SOC storage in both soil layers (0-20 cm = 1492.4 gC m2 and 20-40 cm = 1770.6 gC m2) because of enhanced recalcitrant C (RC) and labile C (LC). The 25 years of inorganic fertilizer treatment did not increase the SOC storage mainly because of the offsetting effects of enhanced RC and decreased LC, whereas no clear SOC increases under the SNPK fertilization resulted from the fast decay rates of soil C.

Safety issues in construction of facilities for long-term storage of radioactive waste at vector site

Energy Technology Data Exchange (ETDEWEB)

Tokarevskyi, O.; Alekseeva, Z.; Kondratiev, S. [State Scientific and Technical Center for Nuclear and Radiation Safety, Kyiv (Ukraine); Rybalka, N. [State Nuclear Regulatory Inspectorate of Ukraine, Kyiv (Ukraine)

2013-07-01

In Ukraine, it is planned to create a number of near-surface facilities for disposal of short-lived RW and long-term (up to 100 years) storage of long-lived RW at the Vector site in the Chernobyl exclusion zone. The expected streams of long-lived RW are analyzed in the paper. According to the analysis of RW streams, in particular, issues are considered on development of RW acceptance criteria, admissible radiological impacts during preparation of RW for long-term storage, reliability of barriers (RW packages, modules and structures, etc.) during long-term storage of RW. (orig.)

Managing aging effects on used fuel dry cask for very long-term storage - 59067

International Nuclear Information System (INIS)

Chopra, Omesh; Diercks, Dwight; Ma, David; Shah, Vikram; Tam, Shiu-Wing; Fabian, Ralph; Liu, Yung; Nutt, Mark

2012-01-01

The cancellation of the Yucca Mountain repository program in the Unites States raises the prospect of very long-term storage (i.e., >120 years) and deferred transportation of used fuel at the nuclear power plant sites. While long-term storage of used nuclear fuel in dry cask storage systems (DCSSs) at Independent Spent Fuel Storage Installations (ISFSIs) is already a standard practice among U.S. utilities, recent rule-making activities of the U.S. Nuclear Regulatory Commission (NRC) indicated additional flexibility for the NRC licensees of ISFSIs and certificate holders of the DCSSs to request initial and renewal terms for up to 40 years. The proposed rule also adds a requirement that renewal applicants must provide descriptions of aging management programs (AMPs) and time-limited aging analyses (TLAAs) to ensure that the structures, systems, and components (SSCs) that are important to safety in the DCSSs will perform as designed under the extended license terms. This paper examines issues related to managing aging effects on DCSSs for very long-term storage (VLTS) of used fuels, capitalizing on the extensive knowledge and experience accumulated from the work on aging research and life cycle management at Argonne National Laboratory (ANL) over the last 30 years. The technical basis for acceptable AMPs and TLAAs is described, as are generic AMPs and TLAAs that are being developed by Argonne under the support of the U.S. Department of Energy (DOE) Used Fuel Disposition Campaign for R and D on extended long-term storage and transportation. (authors)

The challenges facing the long term interim storage

Energy Technology Data Exchange (ETDEWEB)

Iracane, D. [CEA Sacaly, Dir. de la Simulation et des Outils Experimentaux-DSOE, 91 - Gif sur Yvette (France); Marvy, A. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares-DDIN, 91 - Gif Sur Yvette (France)

2001-07-01

In France electricity generation by means of commercial nuclear power plants has come to a point where it contributes to the national demand at a level of 80%. The safety performance of the production system has also reached a high level of both maturity and reliability taking advantage of the cumulative effect of a 30 years long learning experience and ever more stringent safety requirements. The policy to reprocess spent fuel has been overriding but no final decision has yet been made regarding the ultimate disposition of the waste streams. Although studies on deep geological disposal are ongoing, France is also looking at whether and under which conditions a long-term interim storage may provide an effective flexibility to the fuel cycle back-end. We discuss thereafter the needs and the paramount objectives of this latter R and D program. Results are being framed as potential guiding criteria for decision makers and various stakeholders. In first part, we propose a general analysis which emphasises that a long term interim storage is more than a classical nuclear facility because it explicitly requires long-lasting control and creates a burden for Society during many generations. Then, in second part, we offer an overview of the technical results from the R and D program as they stand at the time of writing. As an answer to the Government request, a strong emphasis has been put on this research for three years. Conclusion is an attempt to outline the societal context in which future decisions will have to be made. (author)

The challenges facing the long term interim storage

International Nuclear Information System (INIS)

Iracane, D.; Marvy, A.

2001-01-01

In France electricity generation by means of commercial nuclear power plants has come to a point where it contributes to the national demand at a level of 80%. The safety performance of the production system has also reached a high level of both maturity and reliability taking advantage of the cumulative effect of a 30 years long learning experience and ever more stringent safety requirements. The policy to reprocess spent fuel has been overriding but no final decision has yet been made regarding the ultimate disposition of the waste streams. Although studies on deep geological disposal are ongoing, France is also looking at whether and under which conditions a long-term interim storage may provide an effective flexibility to the fuel cycle back-end. We discuss thereafter the needs and the paramount objectives of this latter R and D program. Results are being framed as potential guiding criteria for decision makers and various stakeholders. In first part, we propose a general analysis which emphasises that a long term interim storage is more than a classical nuclear facility because it explicitly requires long-lasting control and creates a burden for Society during many generations. Then, in second part, we offer an overview of the technical results from the R and D program as they stand at the time of writing. As an answer to the Government request, a strong emphasis has been put on this research for three years. Conclusion is an attempt to outline the societal context in which future decisions will have to be made. (author)

Facile, Large-Quantity Synthesis of Stable, Tunable-Color Silicon Nanoparticles and Their Application for Long-Term Cellular Imaging.

Science.gov (United States)

Zhong, Yiling; Sun, Xiaotian; Wang, Siyi; Peng, Fei; Bao, Feng; Su, Yuanyuan; Li, Youyong; Lee, Shuit-Tong; He, Yao

2015-06-23

We herein introduce a facile, low-cost photochemical method capable of rapid (nanoparticles (SiNPs) of tunable optical properties (peak emission wavelength in the range of 470-560 nm) under ambient air conditions, by introducing 1,8-naphthalimide as a reducing agent and surface ligands. The as-prepared SiNPs feature robust storage stability and photostability preserving strong and stable fluorescent during long-term (>3 h) high-power UV irradiation, in contrast to the rapid fluorescence quenching within 2 h of conventional organic dyes and II-VI quantum dots under the same conditions. The as-prepared SiNPs serving as photostable nanoprobes are workable for cellular imaging in long-term manners. Our findings provide a powerful method for mild-condition and low-cost, large-quantity production of highly fluorescent and photostable SiNPs for various promising applications.

Spent Fuel Long Term Interim Storage: The Spanish Policy

International Nuclear Information System (INIS)

Fernandez-Lopez, Javier

2014-01-01

ENRESA is the Spanish organization responsible for long-term management of all categories of radioactive waste and nuclear spent fuel and for decommissioning nuclear installations. It is also in charge of the management of the funds collected from waste producers and electricity consumers. The national policy about radioactive waste management is established at the General Radioactive Waste Plan by the Government upon proposal of the Ministry of Industry, Energy and Tourism. Now the Plan in force is the Sixth Plan approved in 2006. The policy on spent nuclear fuel, after description of the current available options, is set up as a long term interim storage at a Centralized Temporary Storage facility (CTS, or ATC in Spanish acronym) followed by geologic disposal, pending technological development on other options being eligible in the future. After a site selection process launched in 2009, the site for the ATC has been chosen at the end of 2011. The first steps for the implementation of the facility are described in the present paper. (authors)

The long term storage of advanced gas-cooled reactor (AGR) fuel

International Nuclear Information System (INIS)

Standring, P.N.

1999-01-01

The approach being taken by BNFL in managing the AGR lifetime spent fuel arisings from British Energy reactors is given. Interim storage for up to 80 years is envisaged for fuel delivered beyond the life of the Thorp reprocessing plant. Adopting a policy of using existing facilities, to comply with the principles of waste minimisation, has defined the development requirements to demonstrate that this approach can be undertaken safely and business issues can be addressed. The major safety issues are the long term integrity of both the fuel being stored and structure it is being stored in. Business related issues reflect long term interactions with the rest of the Sellafield site and storage optimisation. Examples of the development programme in each of these areas is given. (author)

Long-Term Storage of Cryptosporidium parvum for In Vitro Culture

NARCIS (Netherlands)

Paziewska-Harris, A.; Schoone, G.; Schallig, H. D. F. H.

2018-01-01

The long-term storage of Cryptosporidium life-cycle stages is a prerequisite for in vitro culture of the parasite. Cryptosporidium parvum oocysts, sporozoites, and intracellular forms inside infected host cells were stored for 6-12 mo in liquid nitrogen utilizing different cryoprotectants (dimethyl

Conditioning radium needles for long term storage : Sri Lankan experience

International Nuclear Information System (INIS)

Ranjith, H.L.A.; Shantha, T.H.S.; Gunaratne, M.G.J.; De Silva, U.W.K.H.; Perera, H.P.H.

2000-01-01

Radium the first radioisotope invented by Madame Curie was used for cancer therapy for the intracavitory treatment of cervical cancers and as oral implants etc. Radium needles and other geometries were made in standard strengths and Radium therapy enjoyed a heyday during the 1st half of the 20th century. Radium-226 is a long-lived radioactive material with a half-life of 1600 years. The use of radium was abandoned in the world in 1980s with the invention of short lived radioactive materials offering remote after loading systems which minimise radiation protection and waste disposal problems associated with long lived radioactive materials. This paper reports the conditioning procedure of the spent radium sources for long term storage (less than 20 years) and transport to national/ international stores if needed. The dose received by those involved in this exercise is also discussed in terms of radiation protection. The Ra was contained for long term storage according to international radiation safety regulations with a surface dose of less than 2 mSv per hour in a conditioned package having 17.5 GBq activity and can be transported to national/international stores if needed. The highest dose received during the exercise is well within the recommended dose limits for occupational exposures (20 and 500 mSv per year) for whole body and extremities respectively

Long-term Stable Conservative Multiscale Methods for Vortex Flows

Science.gov (United States)

2017-10-31

Computing Department, Florida State (January 2016) - L. Rebholz, SIAM Southeast 2016, Special session on Recent advances in fluid flow and...Multiscale Methods for Vortex Flows (x) Material has been given an OPSEC review and it has been determined to be non sensitive and, except for...distribution is unlimited. UU UU UU UU 31-10-2017 1-Aug-2014 31-Jul-2017 Final Report: Long-term Stable Conservative Multiscale Methods for Vortex Flows

Safety and optimization aspects of radioactive waste long-term storage at the ''Vector'' site

International Nuclear Information System (INIS)

Tokarevs'kij, O.V.; Kondrat'jev, S.M.; Aleksjejeva, Z.M.; Ribalka, N.V.

2015-01-01

The paper analyzes links between the final disposal option and needs for long-term storage of radioactive waste taking into proposals on possible changes in radwaste classification as regards disposal. It considers the conceptual approach to design facilities for long-term storage of long-lived radioactive waste at the Vector site and approaches to apply requirements of regulatory documents, radiation safety principles and criteria for long-term storage of radwaste and safety assessment.

Preliminary long-term stability criteria for compressed air energy storage caverns in salt domes

Energy Technology Data Exchange (ETDEWEB)

Thoms, R.L.; Martinez, J.D.

1978-08-01

Air storage caverns, which are an essential and integral component of a CAES plant, should be designed and operated so as to perform satisfactorily over the intended life of the overall facility. It follows that the long-term ''stability'' of air storage caverns must be considered as a primary concern in projecting the satisfactory operation of CAES facilities. As used in the report, ''stability'' of a storage cavern implies the extent to which an acceptable amount of cavern storage volume can be utilized with routine maintenance for a specified time interval, e.g., 35 years. In this context, cavern stability is relative to both planned utilization and time interval of operation. The objective of the study was to review the existing literature and consult knowledgeable workers in the storage industry, and then report state-of-the-art findings relative to long-term stability of compressed air energy storage caverns in salt domes. Further, preliminary cavern stability criteria were to be presented in a form consistent with the amount of information available on cavern performance in salt domes. Another objective of the study was to outline a methodology for determining the long-term stability of site-specific CAES cavern systems in salt domes.

Laboratory test of a prototype heat storage module based on stable supercooling of sodium acetate trihydrate

DEFF Research Database (Denmark)

Dannemand, Mark; Kong, Weiqiang; Fan, Jianhua

2015-01-01

Laboratory test of a long term heat storage module utilizing the principle of stable supercooling of 199.5 kg of sodium acetate water mixture has been carried out. Avoiding phase separation of the incongruently melting salt hydrate by using the extra water principle increased the heat storage...... capacity. An external expansion vessel minimized the pressure built up in the module while heating and reduced the risk of instable supercooling. The module was stable supercooled at indoor ambient temperature for up to two months after which it was discharged. The energy discharged after activating...

International long-term interim storage for spent fuel. An independent storage service investor model

International Nuclear Information System (INIS)

Leister, P.

1999-01-01

Thinking globally the obvious world-wide demands for large storage capacities for spent fuel within the next decades and the newly arising demands for long-term interim storage of spent fuel urges to respond by international interim storage facilities of high capacity. Low cost storage can be achieved only by arranging the storage facility underground in a suitable host rock formation and by selecting the geographical are by an international competition under those countries, who are willing to offer their land. The investor and operator of an international storage facility selected and realised by a competition on the free market as well as the country where the storage is built are both bound by two different kinds of contacts. The main contract is between the offering country/region and the independent operator. The independent operator has in addition a series of contracts with various utilities, which are interested to have their spent fuel stored for a longer period

Potential long-term storage of the predatory mite Phytoseiulus persimilis

Science.gov (United States)

Increasing the ability to store mass-reared natural enemies during periods or seasons of low demand is a critical need of the biocontrol industry. We tested the hypothesis that cryoprotectant or carbohydrate molecules can enhance long-term cold storage of a predatory mite Phytoseiulus persimilis At...

Influence of long-term storage on fire hazard properties of metal nanopowders

Science.gov (United States)

Kyrmakova, O. S.; Sechin, A. I.; Nazarenko, O. B.

2017-08-01

The production and application of nanomaterials is rapidly expanding. Therefore the problem of their properties change during long-term storage becomes essential. The properties of metal nanopowders after long-term storage under ambient conditions were studied and the results are presented in this work. The aluminum, iron, zinc, and copper nanopowders produced by the method of electrical explosion of wires were investigated in this work. The investigation was carried out by X-ray and thermal analysis. The estimation of the flame propagation velocity in the bulk layer of nanopowders was carried out. The characteristics of the nanopowders of nanometals studied are given in terms of their fire hazard. The results can be used for diagnostic of fire hazard of nanomaterials and protection of the enterprises against fire and explosion.

Inventory extension considerations for long-term storage at the nuclear materials storage facility

International Nuclear Information System (INIS)

Olinger, C.T.; Stanbro, W.D.; Longmire, V.; Argo, P.E.; Nielson, S.M.

1996-01-01

Los Alamos National Laboratory is in the process of modifying its nuclear materials storage facility to a long-term storage configuration. In support of this effort, we examined technical and administrative means to extend periods between physical inventories. Both the frequency and sample size during a physical inventory could significantly impact required sizing of the non-destructive assay (NDA) laboratory as well as material handling capabilities. Several options are being considered, including (1) treating each storage location as a separate vault, (2) minimizing the number of items returned for quantitative analysis by optimizing the use of in situ confirmatory measurements, and (3) utilizing advanced monitoring technologies. Careful consideration of these parameters should allow us to achieve and demonstrate safe and secure storage while minimizing the impact on facility operations and without having to increase the size of the NDA laboratory beyond that required for anticipated shipping and receiving activities

Long-term interim storage concepts with conditioning strategies ensuring compatibility with subsequent disposal or reprocessing

International Nuclear Information System (INIS)

Moitrier, C.; Tirel, I.; Villard, C.

2000-01-01

The objective of the CEA studies carried out under research topic 3 (long-term interim storage) of the 1991 French radioactive waste management law is to demonstrate the industrial feasibility of a comprehensive, flexible interim storage facility by thoroughly evaluating and comparing all the basic components of various interim storage concepts. In this context, the CEA is considering reference solutions or concepts based on three primary components (the package, the interim storage facility and the site) suitable for determining the specifications of a very long-term solution. Some aspects are examined in greater detail, such as the implementation of long-term technologies, conditioning processes ensuring the absence of water and contamination in the facility, or allowance for radioactive decay of the packages. The results obtained are continually compiled in reports substantiating the design options. These studies should also lead to an overall economic assessment in terms of the capital and operating cost requirements, thereby providing an additional basis for selecting the design options. The comparison with existing industrial facilities highlights the technical and economic progress represented by the new generation of interim storage units. (authors)

A long-term analysis of pumped hydro storage to firm wind power

International Nuclear Information System (INIS)

Foley, A.M.; Leahy, P.G.; Li, K.; McKeogh, E.J.; Morrison, A.P.

2015-01-01

Highlights: • This is a long term generation analysis of a high wind power system. • A high CO 2 and fossil fuel price is closest to Ireland’s EU ETS 2020 target. • New pumped storage to firm wind is limited unless strong market costs exist. • Reserve for wind power show that ancillary services are relevant for balancing. - Abstract: Although pumped hydro storage is seen as a strategic key asset by grid operators, financing it is complicated in new liberalised markets. It could be argued that the optimum generation portfolio is now determined by the economic viability of generators based on a short to medium term return on investment. This has meant that capital intensive projects such as pumped hydro storage are less attractive for wholesale electricity companies because the payback periods are too long. In tandem a significant amount of wind power has entered the generation mix, which has resulted in operating and planning integration issues due to wind’s inherent uncertain, varying spatial and temporal nature. These integration issues can be overcome using fast acting gas peaking plant or energy storage. Most analysis of wind power integration using storage to date has used stochastic optimisation for power system balancing or arbitrage modelling to examine techno-economic viability. In this research a deterministic dynamic programming long term generation expansion model is employed to optimise the generation mix, total system costs and total carbon dioxide emissions, and unlike other studies calculates reserve to firm wind power. The key finding of this study is that the incentive to build capital-intensive pumped hydro storage to firm wind power is limited unless exogenous market costs come very strongly into play. Furthermore it was demonstrated that reserve increases with increasing wind power showing the importance of ancillary services in future power systems

Using electrophysiology to demonstrate that cueing affects long-term memory storage over the short term.

Science.gov (United States)

Maxcey, Ashleigh M; Fukuda, Keisuke; Song, Won S; Woodman, Geoffrey F

2015-10-01

As researchers who study working memory, we often assume that participants keep a representation of an object in working memory when we present a cue that indicates that the object will be tested in a couple of seconds. This intuitively accounts for how well people can remember a cued object, relative to their memory for that same object presented without a cue. However, it is possible that this superior memory does not purely reflect storage of the cued object in working memory. We tested the hypothesis that cues presented during a stream of objects, followed by a short retention interval and immediate memory test, can change how information is handled by long-term memory. We tested this hypothesis by using a family of frontal event-related potentials believed to reflect long-term memory storage. We found that these frontal indices of long-term memory were sensitive to the task relevance of objects signaled by auditory cues, even when the objects repeated frequently, such that proactive interference was high. Our findings indicate the problematic nature of assuming process purity in the study of working memory, and demonstrate that frequent stimulus repetitions fail to isolate the role of working memory mechanisms.

Long-term storage of radioactive waste: IAEA perspectives on safety and sustainability

International Nuclear Information System (INIS)

Rowat, J.H.; Louvat, D.; Metcalf, P.E.

2006-01-01

As the amounts of radioactive waste in surface storage have increased, concern has grown over the safety and sustainability of storage in the long term. In response to increasing concerns, the International Atomic Energy Agency (IAEA) has included an action to address the safety implications of the long-term storage (LTS) of radioactive waste in its action plan for waste safety; the action plan was endorsed by the IAEA's Member States in 2001. In 2003, the IAEA published a position paper on the safety and sustainability of LTS as part fulfilment of the action in question. A key theme of the position paper is the contrast of safety and sustainability implications of LTS with those of disposal. The present paper provides a summary of the position paper, describes current IAEA activities that deal with the subject of LTS, and discusses findings from the 2004 Cordoba symposium on disposal of low activity radioactive waste that pertain to LTS. (author)

9975 Shipping Package Performance Of Alternate Materials For Long-Term Storage Application

International Nuclear Information System (INIS)

Skidmore, E.; Hoffman, E.; Daugherty, W.

2010-01-01

The Model 9975 shipping package specifies the materials of construction for its various components. With the loss of availability of material for two components (cane fiberboard overpack and Viton(reg s ign) GLT O-rings), alternate materials of construction were identified and approved for use for transport (softwood fiberboard and Viton(reg s ign) GLT-S O-rings). As these shipping packages are part of a long-term storage configuration at the Savannah River Site, additional testing is in progress to verify satisfactory long-term performance of the alternate materials under storage conditions. The test results to date can be compared to comparable results on the original materials of construction to draw preliminary conclusions on the performance of the replacement materials.

Long-term storage method for soft X-ray irradiated 'Hyuganatsu' pollen

International Nuclear Information System (INIS)

Yano, S.; Tanaka, M.; Ohara, N.

2008-01-01

The long-term storage conditions for 'Hyuganatsu ' pollen that had been irradiated with soft X-rays was examined. This study, was aimed at production of 'Tosa-buntan' without formation of nuclear fruit. 1. We evaluated the germination rate of pollen that had been irradiated with soft X-ray (500 or 1,000 Gy) and stored at 3 deg C, -20 deg C, and -40 deg C. The germination rate was the same as that of unirradiated pollen, even after storage for 1 year. Soft X-ray irradiation did not influence the storage attributes of pollen. 2. In unirradiated pollen and pollen that had been irradiated with soft X-ray (500 or 1,000 Gy), temperature conditions necessary for storing from 3 months to 1 year were -20 deg C or less, and pollen stored at -40 deg C had a higher germination rate after 1 year. 3. The germination rate was 1% or less in 4 months if silica gel was sealed into a gas barrier bag with 1,000 Gy-irradiated pollen at a rate of 10:1 (w/w). The ability to germinate was completely lost after 1 year in these conditions. 4. We evaluated the effect of sealing methods on 1,000 Gy-irradiated pollen stored at -20 deg C. There was no difference in germination rates among pollen stored in gas-barrier bags, vacuum-packaged pollen, and pollen stored with nitrogen in gas-barrier bags. Moreover, the germination rate of 750 Gy-irradiated pollen stored at -20 deg C decreased from 3 months onwards when pollen was stored with a free-oxygen absorber (Ageless ZP). 5. Pollen that was treated with acetone before or after soft X-ray irradiation (750 Gy) withstood long-term storage of 1 year. Long-term storage was possible if pollen was stored at -20 deg C, as is the case for rough pollen

Iodide and iodate sodalites for the long-term storage of iodine-129

International Nuclear Information System (INIS)

Strachan, D.M.; Babad, H.

1979-01-01

There exist several proposals for the storage of 129 I. None of these propose the use of a mineral with demonstrated geologic stability. The work described in this paper has identified the minerals iodide and iodate sodalites [Na 8 (AlSiO 4 ) 6 I 2 /(IO 3 ) 2 ] as good candidates for the long-term storage of 129 I. 4 tables

Criticality safety evaluation for long term storage of FFTF fuel in interim storage casks

International Nuclear Information System (INIS)

Richard, R.F.

1995-01-01

It has been postulated that a degradation phenomenon, referred to as ''hot cell rot'', may affect irradiated FFTF mixed plutonium-uranium oxide (MOX) fuel during dry interim storage. ''Hot cell rot'' refers to a variety of phenomena that degrade fuel pin cladding during exposure to air and inert gas environments. It is thought to be a form of caustic stress corrosion cracking or environmentally assisted cracking. Here, a criticality safety analysis was performed to address the effect of the ''hot cell rot'' phenomenon on the long term storage of irradiated FFTF fuel in core component containers. The results show that seven FFTF fuel assemblies or six Ident-69 pin containers stored in core component containers within interim storage casks will remain safely subcritical

The Canadian long-term experimental used fuel storage program

International Nuclear Information System (INIS)

Wasywich, K.M.; Taylor, P.

1993-01-01

The Canadian experimental fuel storage program consists of four components: (1) storage of used CANDU (CANadian Deuterium Uranium, registered trademark of AECL) fuel under water, with periodic examination; (2) storage of used CANDU fuel in dry air at seasonally varying temperatures, and in both dry and moisture-saturated air at 150 C, also with periodic examination; (3) underlying research on the oxidation of unused and used UO 2 in dry and moist air at temperatures up to 300 C; and (4) modeling of UO 2 oxidation in dry air. The primary objective of the fuel-storage experiments is to investigate the stability of used CANDU fuel during long-term storage. Burnup of the fuel in these experiments ranges from ∼43 to 582 MW h/kg U, while the outer-element linear power ratings range from 22 to 79 kW/m. The storage behavior of intact and intentionally defected fuel, and fuel that defected in-reactor, is being investigated in the above experiments. Since differences in UO 2 oxidation behavior were observed between dry-air, moisture-saturated air and wet storage of intentionally defected used CANDU fuel, underlying research was initiated on oxidation of unused and used fuel to develop a better understanding of the different mechanisms. Modeling of UO 2 oxidation based on the results of the dry-storage experiments is also under way

Development of an evaluation method for long-term sealability of the spent fuel storage cask

International Nuclear Information System (INIS)

Kato, Osamu; Ito, Chihiro; Saegusa, Toshiari

1996-01-01

One of the characteristics of the cask storage method of spent fuel is that containment of radioactive materials is assured by the storage cask itself. Thus, the seal structure of the cask is designed to have a highly reliable multi-barrier system using metallic gaskets instead of the conventional rubber gaskets. Although, it has been reported that the containment feature of the metallic gaskets is influenced by the plastic deformation and stress relaxation of the gaskets for a short-term usage, no research report has been published on the containment feature of the metallic gaskets for a long-term usage. In this paper, the stress relaxation features of the metallic gaskets is investigated which will directly influence the long-term sealability of the storage cask, at first. Next, the relationship between the temperature/time dependence of the plastic deformation and the containment features of the metallic gaskets. Finally, an evaluation method of the long-term sealability from experimental data of a short-term behavior of the metallic gaskets is proposed. (author)

INAA applied to halogen (Br and I) stability in long-term storage of lyophilized biological materials

International Nuclear Information System (INIS)

Zaichick, V.; Zaichick, S.

2000-01-01

Instrumental neutron activation analysis (INAA) was used to determine the Br and I concentration in the same ten lyophilized and homogenized human thyroid samples prior and after a 20-year storage at room temperature. It was found that long-term storage had no effect on the iodine content. At the same time, the bromine content was about 2-fold lower (p<0.01). It was assumed that possible losses of other halogens can occur under long-term storage of lyophilized biological materials at room temperature. (author)

Quantifying and isolating stable soil organic carbon using long-term bare fallow experiment

DEFF Research Database (Denmark)

Barré, P; Eglin, T; Christensen, Bent Tolstrup

2010-01-01

. We analyzed data from six bare fallow experiments of long-duration (>30 yrs), covering a range of soil types and climate conditions, and sited at Askov (Denmark), Grignon and Versailles (France), Kursk (Russia), Rothamsted (UK), and Ultuna (Sweden). A conceptual three pool model dividing soil C...... into a labile pool (turnover time of a several years), an intermediate pool (turnover time of a several decades) and a stable pool (turnover time of a several centuries or more) fits well with the long term C decline observed in the bare fallow soils. The estimate of stable C ranged from 2.7 g C kg−1...... at Rothamsted to 6.8 g C kg−1 at Grignon. The uncertainty associated with estimates of the stable pool was large due to the short duration of the fallow treatments relative to the turnover time of stable soil C. At Versailles, where there is least uncertainty associated with the determination of a stable pool...

Long-term storage life of light source modules by temperature cycling accelerated life test

International Nuclear Information System (INIS)

Sun Ningning; Tan Manqing; Li Ping; Jiao Jian; Guo Xiaofeng; Guo Wentao

2014-01-01

Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG. (semiconductor devices)

Interim storage is not long-term disposal

International Nuclear Information System (INIS)

Vincenti, J.R.

1994-01-01

Starting in June 30, 1994 South Carolina enforced an embargo on regular shipments of low-level radioactive waste to the Barnwell repository. The failure of 31 states and their respective compacts to provide access to a long-term disposal facility as stipulated by the low-level radioactive Waste Policy Act of 1980 promotes waste disposal gridlock and anticipates another waste disposal crisis. This article discusses the problem using the following topics: Appalachian Compact Users of Radioactive Isotopes (ACURI) Association's interest; the problem of denial of access to Barnwell; pro and contra interim storage; vital services and benefits at risk; issues at the ACURI meeting; nobel Prize winners use radioactive materials; if perception is reality, politics is prevalent

Long-term behaviour of concrete under saline conditions for long-term stable sealing structures; Langzeitverhalten von Beton unter salinaren Bedingungen fuer langzeitstabile Verschlussbauwerke

Energy Technology Data Exchange (ETDEWEB)

Dahlhaus, Frank; Haucke, Joerg [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Bergbau und Spezialtiefbau

2012-03-15

The authors of the contribution under consideration examine the long-term behaviour of concrete under saline conditions and in particular the suitability of the dam construction materials salt concrete and brine concrete for the use as a part of a sealing system of long-term stable geotechnical sealing structures. The long-term stability of the building material mainly is determined by the corrosion of the cement paste phases. The specific shrinkage behaviour of the construction material is analyzed experimentally in order to verify the expected cracks. The mechanisms of cracking in the salt concrete and brine concrete are analyzed by means of a mesomechanical approach in numerical finite-element calculations.

Stability of selected serum hormones and lipids after long-term storage in the Janus Serum Bank.

Science.gov (United States)

Gislefoss, Randi E; Grimsrud, Tom K; Mørkrid, Lars

2015-04-01

The potential value of a biobank depends on the quality of the samples, i.e. how well they reflect the biological or biochemical state of the donors at the time of sampling. Documentation of sample quality has become a particularly important issue for researchers and users of biobank studies. The aim of this study was to investigate the long-term stability of selected components: cholesterol, high density cholesterol (HDLC), low density cholesterol (LDLC), apolipoprotein A1 (apo-A1), apolipoprotein B (apo B), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH) and free thyroxin (FT4). Samples, stored at -25°C, from 520 men aged 40-49 years at blood sampling distributed in equally sized groups (n=130) according to length of storage, 0, 4, 17 and 29 years, respectively, were used in a cross sectional design. The freshly collected serum samples were used as a reference group to calculate storage related changes. The differences between fresh samples and samples stored for 29 years were substantial for apo-A1 (+12%), apo-B (+22.3%), HDLC (-69.2%), LDLC (+31.3%), and PRL (-33.5%), while total cholesterol, FSH, LH, TSH and FT4 did not show any significant difference. The study showed large differences in serum level of the selected components. The lipids and apolipoproteins were all changed except for total cholesterol. Most hormones investigated (FSH, LH, TSH and FT4) proved to be stable after 29 years of storage while PRL showed sign of degradation. The observed differences are probably due to long-term storage effects and/or external factors (i.e. diet and smoking). Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Long-term storage of compressed radioactive krypton in cylinders

International Nuclear Information System (INIS)

Niephaus, D.; Nommensen, O.; Bruecher, H.

1982-01-01

The recommendations of the German Radiation Protection Commission necessitate the separation of the radioactive noble gas krypton-85 (Kr-85) produced in large LWR reprocessing plants from the dissolver off-gas. A possible method of removal is a long-term storage of the compressed noble gas above ground in cylinders. The aim of the present study is to develop such a storage concept and evaluate its feasibility under the aspects of safety and cost. After having been filled, the gas cylinders are placed separately into transport racks serving to protect the cylinders. Following this, the cylinders are transferred out of the filling station in a transport cask, conveyed to the storage building and stored there. The storage building protects the gas cylinders against external impacts. The storage cells constitute a second barrier against the release of Kr-85. The heat produced during decay of the Kr-85 in the gas cylinders is carried off by natural convection of the air circulating in the storage cells. To study possible corrosion attack on special steels due to rubidium, experiments were conducted at 200 0 C during test periods up to 3500h. In order to compare properties at elevated temperatures, corrosion experiments were conducted at 500 0 C, which is far above the maximum licensed storage temperature of 200 0 C. Experiments were conducted concerning the adsorption of krypton on various adsorbents, thus reducing the pressure inside the gas cylinder during storage. A cost estimate based on 1980 prices

Final Long-Term Management and Storage of Elemental Mercury Environmental Impact Statement Volume 2

Energy Technology Data Exchange (ETDEWEB)

2011-01-01

Pursuant to the Mercury Export Ban Act of 2008 (P.L. 110-414), DOE was directed to designate a facility or facilities for the long-term management and storage of elemental mercury generated within the United States. Therefore, DOE has analyzed the storage of up to 10,000 metric tons (11,000 tons) of elemental mercury in a facility(ies) constructed and operated in accordance with the Solid Waste Disposal Act, as amended by the Resource Conservation and Recovery Act (74 FR 31723). DOE prepared this Final Mercury Storage EIS in accordance with the National Environmental Policy Act of 1969 (NEPA), as amended (42 U.S.C. 4321 et seq.), the Council on Environmental Quality (CEQ) implementing regulations (40 CFR 1500–1508), and DOE’s NEPA implementing procedures (10 CFR 1021) to evaluate reasonable alternatives for a facility(ies) for the long-term management and storage of elemental mercury. This Final Mercury Storage EIS analyzes the potential environmental, human health, and socioeconomic impacts of elemental mercury storage at seven candidate locations: Grand Junction Disposal Site near Grand Junction, Colorado; Hanford Site near Richland, Washington; Hawthorne Army Depot near Hawthorne, Nevada; Idaho National Laboratory near Idaho Falls, Idaho; Kansas City Plant in Kansas City, Missouri; Savannah River Site near Aiken, South Carolina; and Waste Control Specialists, LLC, site near Andrews, Texas. As required by CEQ NEPA regulations, the No Action Alternative was also analyzed as a basis for comparison. DOE intends to decide (1) where to locate the elemental mercury storage facility(ies) and (2) whether to use existing buildings, new buildings, or a combination of existing and new buildings. DOE’s Preferred Alternative for the long-term management and storage of mercury is the Waste Control Specialists, LLC, site near Andrews, Texas.

Final Long-Term Management and Storage of Elemental Mercury Environmental Impact Statement Volume1

Energy Technology Data Exchange (ETDEWEB)

2011-01-01

Pursuant to the Mercury Export Ban Act of 2008 (P.L. 110-414), DOE was directed to designate a facility or facilities for the long-term management and storage of elemental mercury generated within the United States. Therefore, DOE has analyzed the storage of up to 10,000 metric tons (11,000 tons) of elemental mercury in a facility(ies) constructed and operated in accordance with the Solid Waste Disposal Act, as amended by the Resource Conservation and Recovery Act (74 FR 31723).DOE prepared this Final Mercury Storage EIS in accordance with the National Environmental Policy Act of 1969 (NEPA), as amended (42 U.S.C. 4321 et seq.), the Council on Environmental Quality (CEQ) implementing regulations (40 CFR 1500–1508), and DOE’s NEPA implementing procedures (10 CFR 1021) to evaluate reasonable alternatives for a facility(ies) for the long-term management and storage of elemental mercury. This Final Mercury Storage EIS analyzes the potential environmental, human health, and socioeconomic impacts of elemental mercury storage at seven candidate locations:Grand Junction Disposal Site near Grand Junction, Colorado; Hanford Site near Richland, Washington; Hawthorne Army Depot near Hawthorne, Nevada; Idaho National Laboratory near Idaho Falls, Idaho;Kansas City Plant in Kansas City, Missouri; Savannah River Site near Aiken, South Carolina; and Waste Control Specialists, LLC, site near Andrews, Texas. As required by CEQ NEPA regulations, the No Action Alternative was also analyzed as a basis for comparison. DOE intends to decide (1) where to locate the elemental mercury storage facility(ies) and (2) whether to use existing buildings, new buildings, or a combination of existing and new buildings. DOE’s Preferred Alternative for the long-term management and storage of mercury is the Waste Control Specialists, LLC, site near Andrews, Texas.

Predicting long-term performance of engineered geologic carbon dioxide storage systems to inform decisions amidst uncertainty

Science.gov (United States)

Pawar, R.

2016-12-01

Risk assessment and risk management of engineered geologic CO2 storage systems is an area of active investigation. The potential geologic CO2 storage systems currently under consideration are inherently heterogeneous and have limited to no characterization data. Effective risk management decisions to ensure safe, long-term CO2 storage requires assessing and quantifying risks while taking into account the uncertainties in a storage site's characteristics. The key decisions are typically related to definition of area of review, effective monitoring strategy and monitoring duration, potential of leakage and associated impacts, etc. A quantitative methodology for predicting a sequestration site's long-term performance is critical for making key decisions necessary for successful deployment of commercial scale geologic storage projects where projects will require quantitative assessments of potential long-term liabilities. An integrated assessment modeling (IAM) paradigm which treats a geologic CO2 storage site as a system made up of various linked subsystems can be used to predict long-term performance. The subsystems include storage reservoir, seals, potential leakage pathways (such as wellbores, natural fractures/faults) and receptors (such as shallow groundwater aquifers). CO2 movement within each of the subsystems and resulting interactions are captured through reduced order models (ROMs). The ROMs capture the complex physical/chemical interactions resulting due to CO2 movement and interactions but are computationally extremely efficient. The computational efficiency allows for performing Monte Carlo simulations necessary for quantitative probabilistic risk assessment. We have used the IAM to predict long-term performance of geologic CO2 sequestration systems and to answer questions related to probability of leakage of CO2 through wellbores, impact of CO2/brine leakage into shallow aquifer, etc. Answers to such questions are critical in making key risk management

A free-air system for long-term stable carbon isotope labeling of adult forest trees

Science.gov (United States)

Stable carbon (C) isotopes, in particular employed in labeling experiments, are an ideal tool to broaden our understanding of C dynamics in trees and forest ecosystems. Here, we present a free-air exposure system, named isoFACE, designed for long-term stable C isotope labeling in...

Safe transport of spent fuels after long-term storage

International Nuclear Information System (INIS)

Aritomi, M.; Takeda, T.; Ozaki, S.

2004-01-01

Considering the scarcity of energy resources in Japan, a nuclear energy policy pertaining to the spent fuel storage has been adopted. The nuclear energy policy sets the rules that spent fuels generated from LWRs shall be reprocessed and that plutonium and unburnt uranium shall be recovered and reused. For this purpose, a reprocessing plant, which has a reprocessing capability of 800 ton/yr, is under construction at Rokkasho Village. However, it is anticipated that the start of its operation will be delayed. In addition, the amount of spent fuels generated from nuclear power plants exceeds its reprocessing capability. Therefore, the establishment of storage technology for spent fuels becomes an urgent problem in Japan in order to continue smoothly the LWR operations. In this paper, the background of nuclear power generation in Japan is introduced at first. Next, the policy of spent fuel storage in Japan and circumstances surrounding the spent fuels in Japan are mentioned. Furthermore, the major subjects for discussions to settle and improve 'Standard for Safety Design and Inspection of Metal Casks for Spent Fuel Interim Storage Facility' in Atomic Energy Society of Japan are discussed, such as the integrity of fuel cladding, basket, shielding material and metal gasket for the long term storage for achieving safe transport of spent fuels after the storage. Finally, solutions to the unsolved subject in establishing the spent fuel interim storage technologies ase introduced accordingly

Post-thaw sperm characteristics following long-term storage of boar semen in liquid nitrogen.

Science.gov (United States)

Fraser, L; Strzeżek, J; Kordan, W

2014-06-30

This study investigated the effect of long-term liquid nitrogen storage of semen from individual boars on post-thaw sperm characteristics. Ejaculates, collected from five Polish large white (PLW) and five Polish landrace (PLR) boars, were frozen using a standard cryopreservation protocol. Post-thaw analysis was performed within a week (Period 1) and 42-48 months (Period 2) of semen storage in liquid nitrogen. Post-thaw sperm assessments included total motility, mitochondrial function (JC-1/PI assay), plasma membrane integrity (SYBR-14/PI assay), osmotic resistance test (ORT), lipid peroxidation (LPO) status and DNA fragmentation, analysed by the neutral Comet assay. Individual boar variability within breed and cryostorage periods had significant effects on the analysed parameters of frozen-thawed spermatozoa. Prolonged semen storage in liquid nitrogen (Period 2) induced a marked reduction in post-thaw sperm motility, mitochondrial function and plasma membrane integrity in most of the boars. Post-thaw semen of eight boars exhibited a marked decrease in osmotic resistance of the sperm acrosomal membrane, whereas a significant increase in the sperm cryo-susceptibility to induced LPO and DNA fragmentation was observed only in three boars after long-term semen storage. Additionally, frozen-thawed spermatozoa of PLR boars exhibited significantly lower osmotic resistance of the acrosomal membrane than PLW boars following prolonged semen storage in liquid nitrogen. The results of this study provide evidence of ageing processes in frozen-thawed boar spermatozoa following prolonged cryostorage. It seems that, even though cryopreservation allows long-term semen storage in liquid nitrogen, spermatozoa from individual boars are more susceptible to cryo-induced damage. Copyright © 2014 Elsevier B.V. All rights reserved.

Long-term management impacts on carbon storage in Lake States forests

Science.gov (United States)

Matthew Powers; Randall Kolka; Brian Palik; Rachel McDonald; Martin. Jurgensen

2011-01-01

We examined carbon storage following 50+ years of forest management in two long-term silvicultural studies in red pine and northern hardwood ecosystems of North America’s Great Lakes region. The studies contrasted various thinning intensities (red pine) or selection cuttings, shelterwoods, and diameter-limit cuttings (northern hardwoods) to unmanaged controls of...

Tolerance of Ruppia sinensis Seeds to Desiccation, Low Temperature, and High Salinity With Special Reference to Long-Term Seed Storage

Directory of Open Access Journals (Sweden)

Ruiting Gu

2018-03-01

Full Text Available Seeds are important materials for the restoration of globally-threatened marine angiosperm (seagrass populations. In this study, we investigated the differences between different Ruppia sinensis seed types and developed two feasible long-term R. sinensis seed storage methods. The ability of R. sinensis seeds to tolerate the short-term desiccation and extreme cold had been investigated. The tolerance of R. sinensis seeds to long-term exposure of high salinity, cold temperature, and desiccation had been considered as potential methods for long-term seed storage. Also, three morphological and nine physiological indices were measured and compared between two types of seeds: Shape L and Shape S. We found that: (1 wet storage at a salinity of 30–40 psu and 0°C were the optimal long-term storage conditions, and the proportion of viable seeds reached over 90% after a storage period of 11 months since the seeds were collected from the reproductive shoots; (2 dry condition was not the optimal choice for long-term storage of R. sinensis seeds; however, storing seeds in a dry condition at 5°C and 33 ± 10% relative humidity for 9 months had a relatively high percentage (74.44 ± 2.22% of viable seeds, consequently desiccation exposure could also be an acceptable seed storage method; (3 R. sinensis seeds would lose vigor in the interaction of extreme cold (-27°C and desiccation; (4 there were significant differences in seed weight, seed curvature, and endocarp thickness between the two types of seeds. These findings provided fundamental physiological information for R. sinensis seeds and supported the long-term storage of its seeds. Our results may also serve as useful reference for seed storage of other threatened seagrass species and facilitate their ex situ conservation and habitat restoration.

Tolerance of Ruppia sinensis Seeds to Desiccation, Low Temperature, and High Salinity With Special Reference to Long-Term Seed Storage.

Science.gov (United States)

Gu, Ruiting; Zhou, Yi; Song, Xiaoyue; Xu, Shaochun; Zhang, Xiaomei; Lin, Haiying; Xu, Shuai; Yue, Shidong; Zhu, Shuyu

2018-01-01

Seeds are important materials for the restoration of globally-threatened marine angiosperm (seagrass) populations. In this study, we investigated the differences between different Ruppia sinensis seed types and developed two feasible long-term R. sinensis seed storage methods. The ability of R. sinensis seeds to tolerate the short-term desiccation and extreme cold had been investigated. The tolerance of R. sinensis seeds to long-term exposure of high salinity, cold temperature, and desiccation had been considered as potential methods for long-term seed storage. Also, three morphological and nine physiological indices were measured and compared between two types of seeds: Shape L and Shape S. We found that: (1) wet storage at a salinity of 30-40 psu and 0°C were the optimal long-term storage conditions, and the proportion of viable seeds reached over 90% after a storage period of 11 months since the seeds were collected from the reproductive shoots; (2) dry condition was not the optimal choice for long-term storage of R. sinensis seeds; however, storing seeds in a dry condition at 5°C and 33 ± 10% relative humidity for 9 months had a relatively high percentage (74.44 ± 2.22%) of viable seeds, consequently desiccation exposure could also be an acceptable seed storage method; (3) R. sinensis seeds would lose vigor in the interaction of extreme cold (-27°C) and desiccation; (4) there were significant differences in seed weight, seed curvature, and endocarp thickness between the two types of seeds. These findings provided fundamental physiological information for R. sinensis seeds and supported the long-term storage of its seeds. Our results may also serve as useful reference for seed storage of other threatened seagrass species and facilitate their ex situ conservation and habitat restoration.

Model for low temperature oxidation during long term interim storage

Energy Technology Data Exchange (ETDEWEB)

Desgranges, Clara; Bertrand, Nathalie; Gauvain, Danielle; Terlain, Anne [Service de la Corrosion et du Comportement des Materiaux dans leur Environnement, CEA/Saclay - 91191 Gif-sur-Yvette Cedex (France); Poquillon, Dominique; Monceau, Daniel [CIRIMAT UMR 5085, ENSIACET-INPT, 31077 Toulouse Cedex 4 (France)

2004-07-01

For high-level nuclear waste containers in long-term interim storage, dry oxidation will be the first and the main degradation mode during about one century. The metal lost by dry oxidation over such a long period must be evaluated with a good reliability. To achieve this goal, modelling of the oxide scale growth is necessary and this is the aim of the dry oxidation studies performed in the frame of the COCON program. An advanced model based on the description of elementary mechanisms involved in scale growth at low temperatures, like partial interfacial control of the oxidation kinetics and/or grain boundary diffusion, is developed in order to increase the reliability of the long term extrapolations deduced from basic models developed from short time experiments. Since only few experimental data on dry oxidation are available in the temperature range of interest, experiments have also been performed to evaluate the relevant input parameters for models like grain size of oxide scale, considering iron as simplified material. (authors)

Model for low temperature oxidation during long term interim storage

International Nuclear Information System (INIS)

Desgranges, Clara; Bertrand, Nathalie; Gauvain, Danielle; Terlain, Anne; Poquillon, Dominique; Monceau, Daniel

2004-01-01

For high-level nuclear waste containers in long-term interim storage, dry oxidation will be the first and the main degradation mode during about one century. The metal lost by dry oxidation over such a long period must be evaluated with a good reliability. To achieve this goal, modelling of the oxide scale growth is necessary and this is the aim of the dry oxidation studies performed in the frame of the COCON program. An advanced model based on the description of elementary mechanisms involved in scale growth at low temperatures, like partial interfacial control of the oxidation kinetics and/or grain boundary diffusion, is developed in order to increase the reliability of the long term extrapolations deduced from basic models developed from short time experiments. Since only few experimental data on dry oxidation are available in the temperature range of interest, experiments have also been performed to evaluate the relevant input parameters for models like grain size of oxide scale, considering iron as simplified material. (authors)

Very-long-term storage of fission products

International Nuclear Information System (INIS)

Sousselier, Y.; Pradel, J.; Cousin, O.

The large majority of the fission products, with 99.9 percent of the radioactivity content, do not pose actual problems in storage in a geological formation for which we can guarantee total confinement. Safety of storage in a geological formation for the radionuclides of long half-life is based in particular on the absorption capacity of the geological formations and the example of the Oklo fossil reactor and the retention of Pu which is produced is a striking example. But the problems are not the same, and the properties that we look for in the terrain are not the same. We could thus be led to storage in different geological formations for the fission products and the long-half-life emitters. Their separation is interesting from this point of view, but the date at which the separation is made will not be necessarily that of reprocessing. But there is a question of one or the other, and these storages will offer a very high level of insurance and will present only the potential hazards that are very comparable with those presented by natural conditions

Serum YKL-40 predicts long-term mortality in patients with stable coronary disease

DEFF Research Database (Denmark)

Harutyunyan, Marina; Gøtze, Jens P; Winkel, Per

2013-01-01

We investigated whether the inflammatory biomarker YKL-40 could improve the long-term prediction of death made by common risk factors plus high-sensitivity C-reactive protein (hs-CRP) and N-terminal-pro-B natriuretic peptide (NT-proBNP) in patients with stable coronary artery disease (CAD)....

The design, fabrication, and testing of WETF high-quality, long-term-storage, secondary containment vessels

International Nuclear Information System (INIS)

Fisher, Kane J.

2000-01-01

Los Alamos National Laboratory's Weapons Engineering Tritium Facility (WETF) requires secondary containment vessels to store primary tritium containment vessels. The primary containment vessel provides the first boundary for tritium containment. The primary containment vessel is stored within a secondary containment vessel that provides the secondary boundary for tritium containment. WETF requires high-quality, long-term-storage, secondary tritium containment vessels that fit within a Mound-designed calorimeter. In order to qualify the WETF high-quality, long-term-storage, secondary containment vessels for use at WETF, steps have been taken to ensure the appropriate design, adequate testing, quality in fabrication, and acceptable documentation

Evaluation of long term radiological impact on population close to remediated uranium mill tailings storages

International Nuclear Information System (INIS)

Kerouanton, David; Delgove, Laure

2008-01-01

A methodology is elaborated in order to evaluate the long term radiological impact of remediated uranium mill tailings storage. Different scenarios are chosen and modelled to cover future evolution of the tailings storages. Radiological impact is evaluated for different population such as adults and children living in the immediate vicinity or directly on the storage, road workers or walkers on the storage. Equation and methods are detailed. (author)

Neurocognitive function in clinically stable individuals with long-term bipolar I disorder: Comparisons with schizophrenia patients and controls

Directory of Open Access Journals (Sweden)

Pei-Yun Lin

2017-05-01

Full Text Available This study compared the levels of the five domains of neurocognitive function—executive function, attention, memory, verbal comprehension, and perceptual organization—among clinically stable individuals with long-term bipolar I disorder, individuals with long-term schizophrenia, and a group of controls. We recruited a total of 93 clinically stable individuals with bipolar I disorder, 94 individuals with schizophrenia, and 106 controls in this study. Their neurocognitive function was measured using a series of neurocognitive function tests: the Wechsler Adult Intelligence Scale—Third Edition (WAIS-III, Line Cancellation Test, Visual Form Discrimination, Controlled Oral Word Association Test, Wisconsin Card Sorting Test, Continuous Performance Task, and Wechsler Memory Scale—Third Edition. Neurocognitive function was compared among the three groups through a multivariate analysis of variance. The results indicated that when the effect of age was controlled, clinically stable individuals with bipolar I disorder and those with schizophrenia demonstrated poor neurocognitive function on all tests except for the WAIS-III Similarity and Information and the Line Cancellation Test. The individuals with bipolar I disorder had similar levels of neurocognitive function compared with the schizophrenia group, but higher levels of neurocognitive function on the WAIS-III Comprehension, Controlled Oral Word Association Test, and Wechsler Memory Scale—Third Edition Auditory Immediate and Delayed Index and Visual Immediate and Delayed Index. The conclusions of this study suggest that compared with controls, individuals with long-term bipolar I disorder and those with long-term schizophrenia have poorer neurocognitive function, even when clinically stable. Individuals with long-term bipolar I disorder and those with long-term schizophrenia have similar levels of deficits in several domains of neurocognitive function.

Red blood cell storage duration and long-term mortality in patients undergoing cardiac intervention

DEFF Research Database (Denmark)

Dencker, D; Pedersen, F; Engstrøm, T

2017-01-01

OBJECTIVES: To study the effect of red blood cell (RBC) storage duration on long-term mortality in patients undergoing cardiac intervention. BACKGROUND: RBCs undergo numerous structural and functional changes during storage. Observational studies have assessed the association between RBC storage...... duration and patient outcomes with conflicting results. METHODS: Between January 2006 and December 2014, 82 408 patients underwent coronary angiography. Of these, 1856 patients received one to four RBC units within 30 days after this procedure. Patients were allocated according to length of RBC storage...

Laboratory Testing of Solar Combi System with Compact Long Term PCM Heat Storage

DEFF Research Database (Denmark)

Johansen, Jakob Berg; Englmair, Gerald; Dannemand, Mark

2016-01-01

To enable the transition from fossil fuels as a primary heat source for domestic hot water preparation and space heating solar thermal energy has great potential. The heat from the sun has the disadvantage that it is not always available when there is a demand. To solve this mismatch a thermal...... seasonal storage can be used to store excess heat from the summer to the winter when the demand is higher than the supply. Installing a long term thermal storage in a one family house it needs to be compact and sensible heat storages are not suitable. A latent heat storage with a phase change material (PCM...

Stable long-term chronic brain mapping at the single-neuron level.

Science.gov (United States)

Fu, Tian-Ming; Hong, Guosong; Zhou, Tao; Schuhmann, Thomas G; Viveros, Robert D; Lieber, Charles M

2016-10-01

Stable in vivo mapping and modulation of the same neurons and brain circuits over extended periods is critical to both neuroscience and medicine. Current electrical implants offer single-neuron spatiotemporal resolution but are limited by such factors as relative shear motion and chronic immune responses during long-term recording. To overcome these limitations, we developed a chronic in vivo recording and stimulation platform based on flexible mesh electronics, and we demonstrated stable multiplexed local field potentials and single-unit recordings in mouse brains for at least 8 months without probe repositioning. Properties of acquired signals suggest robust tracking of the same neurons over this period. This recording and stimulation platform allowed us to evoke stable single-neuron responses to chronic electrical stimulation and to carry out longitudinal studies of brain aging in freely behaving mice. Such advantages could open up future studies in mapping and modulating changes associated with learning, aging and neurodegenerative diseases.

Advanced surveillance technologies for used fuel long-term storage and transportation - 59032

International Nuclear Information System (INIS)

Tsai, Hanchung; Liu, Yung Y.; Nutt, Mark; Shuler, James

2012-01-01

Utilities worldwide are using dry-cask storage systems to handle the ever-increasing number of discharged fuel assemblies from nuclear power plants. In the United States and possibly elsewhere, this trend will continue until an acceptable disposal path is established. The recent Fukushima nuclear power plant accident, specifically the events with the storage pools, may accelerate the drive to relocate more of the used fuel assemblies from pools into dry casks. Many of the newer cask systems incorporate dual-purpose (storage and transport) or multiple-purpose (storage, transport, and disposal) canister technologies. With the prospect looming for very long term storage - possibly over multiple decades - and deferred transport, condition- and performance-based aging management of cask structures and components is now a necessity that requires immediate attention. From the standpoint of consequences, one of the greatest concerns is the rupture of a substantial number of fuel rods that would affect fuel retrievability. Used fuel cladding may become susceptible to rupture due to radial-hydride-induced embrittlement caused by water-side corrosion during the reactor operation and subsequent drying/transfer process, through early stage of storage in a dry cask, especially for high burnup fuels. Radio frequency identification (RFID) is an automated data capture and remote-sensing technology ideally suited for monitoring sensitive assets on a long-term, continuous basis. One such system, called ARG-US, has been developed by Argonne National Laboratory for the U.S. Department of Energy's Packaging Certification Program for tracking and monitoring drums containing sensitive nuclear and radioactive materials. The ARG-US RFID system is versatile and can be readily adapted for dry-cask monitoring applications. The current built-in sensor suite consists of seal, temperature, humidity, shock, and radiation sensors. With the universal asynchronous receiver/transmitter interface in

On the pathway towards disposal. The need for long-term interim storage of high-level nuclear waste

International Nuclear Information System (INIS)

Budelmann, Harald; Koehnke, Dennis; Reichardt, Manuel

2017-01-01

The disposal of spent nuclear fuel is a still unsolved problem with social, ethical, economical, ecological and political dimensions. The stagnating decision process on the final repository concept in several countries has the consequence of the inclusion of long-term interim storage into the disposal concept. The contribution discusses several approaches. This opens the question whether the long-term interim storage is a matter of delaying tactic or a pragmatic solution on the way to a final repository.

Radiolytic gas production during long-term storage of nuclear wastes

International Nuclear Information System (INIS)

Bibler, N.E.

1976-01-01

Gases produced by in situ radiolysis of sealed solidified nuclear wastes during long-term storage could conceivably breach containment. Therefore, candidate waste forms (matrices containing simulated nuclear wastes) were irradiated with 60 Co-γ and 244 Cm-α radiation. These forms were: cement containing simulated fission product sludges, vermiculite containing organic liquids, and cellulosics contaminated with α-emitting transuranic isotopes. For cement waste forms exposed to γ-radiolysis, an equilibrium hydrogen pressure was reached that was dose rate dependent. For α-radiolysis, equilibrium was not reached. With organic wastes (n-octane on vermiculite), H 2 and traces of CO 2 and CH 4 were produced, and O 2 was consumed with both radiations. Only energy absorbed by the organic material was effective in producing H 2 . At low dose rates with both α- and γ-irradiations, G(H 2 ) was 4.5 and G(-O 2 ) was 5.0. Also, equilibrium was not obtained. For cellulosic material, H 2 , CO 2 , and CO were produced in the ratio of 1.0:0.7:0.3, and O 2 was consumed. With α-radiolysis, G(gas) was dose dependent; measured values ranged from 2.2 to 0.6 as the dose increased. Implications of all these results on long-term storage of radioactive waste are discussed. Some data from an actual nuclear wasteform are also presented

Evaluation of limiting mechanisms for long-term spent fuel dry storage

International Nuclear Information System (INIS)

Rashid, J.; Machiels, A.

2001-01-01

Several failure mechanisms have been postulated that could become limiting for spent fuel in dry storage. These are: stress Corrosion Cracking (SCC), Delayed Hydride Cracking (DHC) and Creep Rupture (CR). These mechanisms are examined in some detail from two perspectives: their initial environments in which they were developed and applied, and in relation to their applicability to dry storage. Extrapolation techniques are used to transfer the mechanisms from their initial in-reactor and laboratory domains to out-of-reactor spent fuel dry storage environments. This transfer is accomplished both qualitatively where necessary and quantitatively when possible, with fracture toughness used as the transfer function. In this regard, the paper provides useful information on cladding fracture toughness estimates that recognize the specific physical conditions of the cladding, which would not be found elsewhere in the literature. The arguments presented in this paper confirm the general technical consensus that creep is the governing mechanism for spent fuel in long-term dry storage. (author)

Evaluation of limiting mechanisms for long-term spent fuel dry storage

Energy Technology Data Exchange (ETDEWEB)

Rashid, J. [ANATECH Research Corp., San Diego, CA (United States); Machiels, A. [EPRI, Palo Alto, CA (United States)

2001-07-01

Several failure mechanisms have been postulated that could become limiting for spent fuel in dry storage. These are: stress Corrosion Cracking (SCC), Delayed Hydride Cracking (DHC) and Creep Rupture (CR). These mechanisms are examined in some detail from two perspectives: their initial environments in which they were developed and applied, and in relation to their applicability to dry storage. Extrapolation techniques are used to transfer the mechanisms from their initial in-reactor and laboratory domains to out-of-reactor spent fuel dry storage environments. This transfer is accomplished both qualitatively where necessary and quantitatively when possible, with fracture toughness used as the transfer function. In this regard, the paper provides useful information on cladding fracture toughness estimates that recognize the specific physical conditions of the cladding, which would not be found elsewhere in the literature. The arguments presented in this paper confirm the general technical consensus that creep is the governing mechanism for spent fuel in long-term dry storage. (author)

Sheet GT3-2. General approach of life phases on a long term for uranium mining residues storages and comparison with other storages

International Nuclear Information System (INIS)

2009-01-01

This document aims at specifying the short term, middle term and long term boundaries for a sustainable management and rehabilitated ancient uranium mining sites and of uranium mining residue storage sites. It presents a general overview of site evolution in time, and then, more precisely, the different functions (rehabilitation management, corrective actions, control and monitoring, and so on) and equipment (confinement works, measurement system) at stake in the management of these sites and the control of their impacts. Functions and equipment implemented on such a site, as well as time scales corresponding to different approaches are compared with those of other types of storage. The peculiarity of ancient uranium mining sites and its implications in terms of management on a long term are discussed

NPP Krsko: LILW Repository or Long Term Storage

International Nuclear Information System (INIS)

Lokner, V.; Subasic, D.; Levanat, I.

2008-01-01

Construction of the facilities for LILW and SF management, as planned in Decommissioning and LILW and SF management program for NPP Krsko, would be a rather expensive and challenging project for such a small nuclear program. In order to accommodate waste arising from a single nuclear power plant, one LILW repository should be constructed before the end of the NPP operation, then one SF dry storage, and finally one geological repository. This requires relatively urgent identification within Slovenian/Croatian territory of three locations that meet the criteria for establishment of such facilities and are acceptable to the local communities. There are very few such potential locations. The siting process for the first of the three facilities is well under way in Slovenia, because the country wants to have its LILW repository in operation by the year 2013. In order to facilitate public acceptance, Slovenian government has introduced financial incentives to local communities for the repository construction and operation. These 'compensations for limited land use' may significantly increase the overall costs of disposal if the repository is in operation for a long period. In the recent years, however, a possibility of long term storage (LTS) is gaining an increased attention in the waste management community, and has already been introduced e.g. in the Netherlands. It is a particularly viable option for limited waste quantities. Disposal remains the final solution, but present technologies have made possible a relatively inexpensive storage up to about hundred years, which can accommodate LILW, HLW and SF from nuclear programs as well as research reactor waste and NORM. Such storage would be a safe and simple temporary solution, encompassing all immediate and near future waste management needs. In addition, it would increase flexibility and reduce financing requirements for the final waste disposal: providing additional time for reduction of radiation emission and heat

Post-Irradiation Examinations for Resolving Fuel Issues in Long Term Storage

International Nuclear Information System (INIS)

Karlsson, Joakim K.H.; Alvarez Holston, Anna-Maria

2014-01-01

In many countries extended long term dry storage is the solution for storage of spent nuclear fuel for the foreseeable future. The expected storage times have increased over the last years and today storage times of up to 300 years is anticipated. With such long storage times, requirements on transportability and retrievability of the fuel have become more important. Hitherto most investigations on fuel behaviour during dry storage have been focused on cladding creep and the impact of hydrogen and hydrides in the cladding. Creep data gives input to creep models and creep to rupture data helps to set criteria for maximum allowable internal rod pressure. Hydrides lower the ductility of the cladding and this is more pronounced with radially oriented hydrides. As the temperature decreases over time in a dry storage cask dissolved hydrogen will precipitate forming hydrides in addition to hydrides already present. Assuming there is sufficient hoop stress in the cladding, the new hydrides would be radially oriented. Together with lost ductility Delayed Hydride Cracking (DHC) could be a potential mechanism for rod failure over tens of years of dry storage as the temperature drops from about 350 deg. C to 150 deg. C. Hydride embrittlement and the DHC mechanism have been studied in the first Studsvik Cladding Integrity Project (SCIP), although the focus in this program has mainly been on higher temperatures relevant for operating conditions rather than on dry storage conditions. In addition to the mechanisms mentioned there are other failure mechanisms that could potentially threaten the cladding fuel integrity and retrievability. In case there is residual water or moisture available in the cask, or even in the fuel due to existing fuel failures, radiolysis gives free hydrogen and oxygen. In failed fuel this may cause fuel oxidation and swelling affecting fuel integrity. The hydrogen gas pressure will not threaten the cask but be available for cladding uptake. Furthermore

Synaptic remodeling, synaptic growth and the storage of long-term memory in Aplysia.

Science.gov (United States)

Bailey, Craig H; Kandel, Eric R

2008-01-01

Synaptic remodeling and synaptic growth accompany various forms of long-term memory. Storage of the long-term memory for sensitization of the gill-withdrawal reflex in Aplysia has been extensively studied in this respect and is associated with the growth of new synapses by the sensory neurons onto their postsynaptic target neurons. Recent time-lapse imaging studies of living sensory-to-motor neuron synapses in culture have monitored both functional and structural changes simultaneously so as to follow remodeling and growth at the same specific synaptic connections continuously over time and to examine the functional contribution of these learning-related structural changes to the different time-dependent phases of memory storage. Insights provided by these studies suggest the synaptic differentiation and growth induced by learning in the mature nervous system are highly dynamic and often rapid processes that can recruit both molecules and mechanisms used for de novo synapse formation during development.

Long-term sera storage does not significantly modify the interpretation of toxoplasmosis serologies.

Science.gov (United States)

Dard, C; Bailly, S; Drouet, T; Fricker-Hidalgo, H; Brenier-Pinchart, M P; Pelloux, H

2017-03-01

Serological investigation of Toxoplasma gondii can answer many questions about toxoplasmosis in human pathology. Along these lines, studies on serum storage in biobanks need to be performed especially in terms of determining the impact of storage on relevance of sera analysis after freezing. This study assessed the impact of long-term sera storage on the stability of anti-Toxoplasma immunoglobulins. The stability of anti-Toxoplasma IgG and IgM was studied in 244 and 242 sera respectively, stored at -20°C from one month to ten years. ELISA-immunoassay (Vidas®, bioMérieux) was used for initial and post-storage analyses. Linear models for repeated measures and subgroup analyses were performed to assess the effect of storage duration and sample characteristics on immunoglobulins stability. Until ten years, the variability attributed to storage (maximum 8.07% for IgG, 13.17% for IgM) was below the variations inherent to the serological technique and allowed by quality assurance systems (15%). Subgroup analysis reported no variation attributed to sera storage. Serological interpretation was modified for 3 sera (1.2%) tested for IgM, all stored more than seven years. Anti-Toxoplasma immunoglobulins can reliably be measured for at least up to six years of storage with no modification of interpretation of toxoplasmosis serologies. Copyright © 2017 Elsevier B.V. All rights reserved.

Automated and temperature-controlled micro-PIV measurements enabling long-term-stable microchannel acoustophoresis characterization

DEFF Research Database (Denmark)

Augustsson, Per; Barnkob, Rune; Wereley, Steven T.

2011-01-01

We present a platform for micro particle image velocimetry (μPIV), capable of carrying out full-channel, temperature-controlled, long-term-stable, and automated μPIV-measurement of microchannel acoustophoresis with uncertainties below 5% and a spatial resolution in the order of 20 μm. A method to...

Ready-to-use parenteral amiodarone : A feasibility study towards a long-term stable product formulation

NARCIS (Netherlands)

Jacobs, Maartje S.; Luinstra, Marianne; Moes, Jan Reindert; Chan, Tiffany C. Y.; Minovic, Isidor; Frijlink, Henderik W.; Woerdenbag, Herman J.

Objectives To determine the feasibility of preparing a long-term stable ready-to-use parenteral amiodarone formulation using cyclodextrins as dissolution enhancer. Methods A preformulation study was performed with different molar ratios of hydroxypropyl-beta-cyclodextrin (HP-BCD) or

Viability staining and animal infectivity of Cryptosporidium andersoni oocysts after long-term storage

Czech Academy of Sciences Publication Activity Database

Kváč, Martin; Květoňová, Dana; Salát, Jiří; Ditrich, Oleg

2007-01-01

Roč. 100, č. 2 (2007), s. 213-217 ISSN 0932-0113 R&D Projects: GA ČR GA524/05/0992 Institutional research plan: CEZ:AV0Z60220518 Keywords : Cryptosporidium and ersoni * viability * infectivity * long-term storage Subject RIV: EG - Zoology Impact factor: 1.512, year: 2007

Conceptual designs for a long term 238PuO2 storage vessel

International Nuclear Information System (INIS)

Kwon, D.M.; Replogle, W.C.

1996-08-01

This is a report on conceptual designs for a long term, 250 years, storage container for plutonium oxide ([sup 238]PuO[sub 2]). These conceptual designs are based on the use of a quartz filter to release the helium generated during the plutonium decay. In this report a review of filter material selection, design concepts, thermal modeling, and filter performance are discussed

Data collection and storage in long-term ecological and evolutionary studies: The Mongoose 2000 system.

Science.gov (United States)

Marshall, Harry H; Griffiths, David J; Mwanguhya, Francis; Businge, Robert; Griffiths, Amber G F; Kyabulima, Solomon; Mwesige, Kenneth; Sanderson, Jennifer L; Thompson, Faye J; Vitikainen, Emma I K; Cant, Michael A

2018-01-01

Studying ecological and evolutionary processes in the natural world often requires research projects to follow multiple individuals in the wild over many years. These projects have provided significant advances but may also be hampered by needing to accurately and efficiently collect and store multiple streams of the data from multiple individuals concurrently. The increase in the availability and sophistication of portable computers (smartphones and tablets) and the applications that run on them has the potential to address many of these data collection and storage issues. In this paper we describe the challenges faced by one such long-term, individual-based research project: the Banded Mongoose Research Project in Uganda. We describe a system we have developed called Mongoose 2000 that utilises the potential of apps and portable computers to meet these challenges. We discuss the benefits and limitations of employing such a system in a long-term research project. The app and source code for the Mongoose 2000 system are freely available and we detail how it might be used to aid data collection and storage in other long-term individual-based projects.

Long-term Stability of Urinary Biomarkers of Acute Kidney Injury in Children.

Science.gov (United States)

Schuh, Meredith P; Nehus, Edward; Ma, Qing; Haffner, Christopher; Bennett, Michael; Krawczeski, Catherine D; Devarajan, Prasad

2016-01-01

Recent meta-analyses support the utility of urinary biomarkers for the diagnosis and prognosis of acute kidney injury. It is critical to establish optimal sample handling conditions for short-term processing and long-term urinary storage prior to widespread clinical deployment and meaningful use in prospective clinical trials. Prospective study. 80 children (median age, 1.1 [IQR, 0.5-4.2] years) undergoing cardiac surgery with cardiopulmonary bypass at our center. 50% of patients had acute kidney injury (defined as ≥50% increase in serum creatinine from baseline). We tested the effect on biomarker concentrations of short-term urine storage in ambient, refrigerator, and freezer conditions. We also tested the effects of multiple freeze-thaw cycles, as well as prolonged storage for 5 years. Urine concentrations of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule 1 (KIM-1), and interleukin 18 (IL-18). All biomarkers were measured using commercially available kits. All 3 biomarkers were stable in urine stored at 4°C for 24 hours, but showed significant degradation (5.6%-10.1% from baseline) when stored at 25°C. All 3 biomarkers showed only a small although significant decrease in concentration (0.77%-2.9% from baseline) after 3 freeze-thaw cycles. Similarly, all 3 biomarkers displayed only a small but significant decrease in concentration (0.84%-3.2%) after storage for 5 years. Only the 3 most widely studied biomarkers were tested. Protease inhibitors were not evaluated. Short-term storage of urine samples for measurement of NGAL, KIM-1, and IL-18 may be performed at 4°C for up to 24 hours, but not at room temperature. These urinary biomarkers are stable at -80°C for up to 5 years of storage. Our results are reassuring for the deployment of these assays as biomarkers in clinical practice, as well as in prospective clinical studies requiring long-term urine storage. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier

Seismic Performance of Dry Casks Storage for Long- Term Exposure

Energy Technology Data Exchange (ETDEWEB)

Ibarra, Luis [Univ. of Utah, Salt Lake City, UT (United States); Sanders, David [Univ. of Nevada, Reno, NV (United States); Yang, Haori [Oregon State Univ., Corvallis, OR (United States); Pantelides, Chris [Univ. of Utah, Salt Lake City, UT (United States)

2016-12-30

The main goal of this study is to evaluate the long-term seismic performance of freestanding and anchored Dry Storage Casks (DSCs) using experimental tests on a shaking table, as well as comprehensive numerical evaluations that include the cask-pad-soil system. The study focuses on the dynamic performance of vertical DSCs, which can be designed as free-standing structures resting on a reinforced concrete foundation pad, or casks anchored to a foundation pad. The spent nuclear fuel (SNF) at nuclear power plants (NPPs) is initially stored in fuel-storage pools to control the fuel temperature. After several years, the fuel assemblies are transferred to DSCs at sites contiguous to the plant, known as Interim Spent Fuel Storage Installations (ISFSIs). The regulations for these storage systems (10 CFR 72) ensure adequate passive heat removal and radiation shielding during normal operations, off-normal events, and accident scenarios. The integrity of the DSCs is important, even if the overpack does not breach, because eventually the spent fuel-rods need to be shipped either to a reprocessing plant or a repository. DSCs have been considered as a temporary storage solution, and usually are licensed for 20 years, although they can be relicensed for operating periods of up to 60 years. In recent years, DSCs have been reevaluated as a potential mid-term solution, in which the operating period may be extended for up to 300 years. At the same time, recent seismic events have underlined the significant risks DSCs are exposed. The consideration of DCSs for storing spent fuel for hundreds of years has created new challenges. In the case of seismic hazard, longer-term operating periods not only lead to larger horizontal accelerations, but also increase the relative effect of vertical accelerations that usually are disregarded for smaller seismic events. These larger seismic demands could lead to casks sliding and tipping over, impacting the concrete pad or adjacent casks. The casks

Using zeolites for fixation and long-term storage of krypton

International Nuclear Information System (INIS)

Pirogova, G.N.; Voronin, Yu.V.; Pribylov, A.A.; Serpinskii, V.V.; Mirskii, Ya.V.; Almazova, B.B.; Golitsina, V.V.

1993-01-01

It is known that large quantities of 85 Kr are liberated during the operation of nuclear power plants and, in particular, during the processing of nuclear fuel. At the present time, there are several methods of its fixation (accumulation), viz., storage in high-pressure gas balloons, adsorption, plasma-aided implantation into metals, introduction into clathrate compounds, and obtaining kryptonates. Encapsulation in zeolites is one of the most promising methods. The merits of this method include safety during storage, a favorable volume-to-mass ratio, the possibility of separating krypton from a mixture of different gases, and purity of the encapsulated gas. The encapsulation technique has been developed quite recently. Several recent reports established the possibility of encapsulating krypton in the 3A-type zeolites. However, most of the investigators observed leakage during the storage of the zeolite-gas system and complete liberation of krypton from the zeolite during prolonged storage. This paper deals with a study of the encapsulation process of krypton in the zeolites obtained by cation exchange from NaA. The experimental specimens were characterized by the degree of exchange of sodium into potassium and cesium. It is known that the introduction of cesium into the structure (body) of a zeolite reduces the size of the window of entrance. All the synthesized specimens were used in their granulated form. The aim of this study was to develop zeolite specimens for carrying out long-term storage of krypton

Final Long-Term Management and Storage of Elemental Mercury Environmental Impact Statement Summary and Guide for Stakeholders

Energy Technology Data Exchange (ETDEWEB)

2011-01-01

Pursuant to the Mercury Export Ban Act of 2008 (P.L. 110-414), DOE was directed to designate a facility or facilities for the long-term management and storage of elemental mercury generated within the United States. Therefore, DOE has analyzed the storage of up to 10,000 metric tons (11,000 tons) of elemental mercury in a facility(ies) constructed and operated in accordance with the Solid Waste Disposal Act, as amended by the Resource Conservation and Recovery Act (74 FR 31723). DOE prepared this Final Mercury Storage EIS in accordance with the National Environmental Policy Act of 1969 (NEPA), as amended (42 U.S.C. 4321 et seq.), the Council on Environmental Quality (CEQ) implementing regulations (40 CFR 1500–1508), and DOE’s NEPA implementing procedures (10 CFR 1021) to evaluate reasonable alternatives for a facility(ies) for the long-term management and storage of elemental mercury. This Final Mercury Storage EIS analyzes the potential environmental, human health, and socioeconomic impacts of elemental mercury storage at seven candidate locations: Grand Junction Disposal Site near Grand Junction, Colorado; Hanford Site near Richland, Washington; Hawthorne Army Depot near Hawthorne, Nevada; Idaho National Laboratory near Idaho Falls, Idaho; Kansas City Plant in Kansas City, Missouri; Savannah River Site near Aiken, South Carolina; and Waste Control Specialists, LLC, site near Andrews, Texas. As required by CEQ NEPA regulations, the No Action Alternative was also analyzed as a basis for comparison. DOE intends to decide (1) where to locate the elemental mercury storage facility(ies) and (2) whether to use existing buildings, new buildings, or a combination of existing and new buildings. DOE’s Preferred Alternative for the long-term management and storage of mercury is the Waste Control Specialists, LLC, site near Andrews, Texas.

Long-term intensive management increased carbon occluded in phytolith (PhytOC) in bamboo forest soils

Science.gov (United States)

Huang, Zhang-Ting; Li, Yong-Fu; Jiang, Pei-Kun; Chang, Scott X.; Song, Zhao-Liang; Liu, Juan; Zhou, Guo-Mo

2014-01-01

Carbon (C) occluded in phytolith (PhytOC) is highly stable at millennium scale and its accumulation in soils can help increase long-term C sequestration. Here, we report that soil PhytOC storage significantly increased with increasing duration under intensive management (mulching and fertilization) in Lei bamboo (Phyllostachys praecox) plantations. The PhytOC storage in 0-40 cm soil layer in bamboo plantations increased by 217 Mg C ha-1, 20 years after being converted from paddy fields. The PhytOC accumulated at 79 kg C ha-1 yr-1, a rate far exceeding the global mean long-term soil C accumulation rate of 24 kg C ha-1 yr-1 reported in the literature. Approximately 86% of the increased PhytOC came from the large amount of mulch applied. Our data clearly demonstrate the decadal scale management effect on PhytOC accumulation, suggesting that heavy mulching is a potential method for increasing long-term organic C storage in soils for mitigating global climate change.

ULTimateCO2 - State of the art report. Dealing with uncertainty associated with long-term CO2 geological storage

International Nuclear Information System (INIS)

2014-01-01

ULTimateCO2, a four-year collaborative project financed by the 7. Framework Programme and coordinated by BRGM, aims to shed more light on the long-term processes associated with the geological storage of CO 2 . ULTimateCO2 unites 12 partners (research institutes, universities, industrialists) and a varied panel of experts (NGOs, national authority representatives, IEAGHG,...). Based on a multidisciplinary approach, and bringing together laboratory experiments, numerical modelling and natural analogue field studies, ULTimateCO2 will increase our understanding of the long-term effects of CO 2 Capture and Storage (CCS) in terms of hydrodynamics, geochemistry, mechanics of the storage formations and their vicinity. The report contains the partners' pooled knowledge and provides a view of the current state-of-the-art for the issues addressed by this project: - The long-term reservoir trapping efficiency (WP3); - The long-term sealing integrity of faulted and fractured cap-rock (WP4); - The near-well leakage characterisation and chemical processes (WP5); - The long-term behavior of stored CO 2 looking at the basin scale (WP2); - Uncertainty assessment (WP6). Each chapter is divided into two sections: (i) a summary which explains in 'simple words' the main issues and objectives of the WP, and (ii) a current state of the art section which provides a more sound review on the specific studied processes. The aim is to provide answers to pertinent questions from a variety of users, particularly project owners, site operators and national authorities, about their exposure to uncertainty downstream of closure of a CO 2 geological storage site

Effects of marrow storage at 4 degrees C on the subsequent generation of long-term marrow cultures

International Nuclear Information System (INIS)

Takahashi, M.; Singer, J.W.

1985-01-01

The present study was undertaken to examine the effect of marrow preservation at 4 degrees C on subsequent long-term culture, which evaluates both hematopoietic precursor cells and hematopoietic microenvironmental cells. Storage of unfractionated marrow was superior to storage of buffy-coat cells in tissue culture medium with 20% fetal calf serum. CFU-C recovery in unfractionated marrow was 48.4% at four days and 21.4% at seven days. Long-term marrow cultures from cells stored at 4 degrees C for up to seven days produced CFU-C for up to seven weeks and established confluent marrow stromal cell layers. Suspension cultures of marrow cells preserved at 4 degrees C for seven days cultured with irradiated allogeneic marrow stromal cell layers from normal long-term marrow cultures showed significantly increased CFU-C production from week 2 to week 5 when compared with the control cultures without adherent cell layers. These data suggest that marrow storage at 4 degrees C for up to seven days preserves early hematopoietic precursor cells and microenvironmental cells and may be used for autologous rescue from marrow ablative therapy

Managing aging effects on dry cask storage systems for extended long-term storage and transportation of used fuel - rev. 0

Energy Technology Data Exchange (ETDEWEB)

Chopra, O.K.; Diercks, D.; Fabian, R.; Ma, D.; Shah, V.; Tam, S.W.; Liu, Y. (Decision and Information Sciences); ( EVS); ( NE)

2012-07-06

The cancellation of the Yucca Mountain repository program in the United States raises the prospect of extended long-term storage (i.e., >120 years) and deferred transportation of used fuel at operating and decommissioned nuclear power plant sites. Under U.S. federal regulations contained in Title 10 of the Code of Federal Regulations (CFR) 72.42, the initial license term for an Independent Spent Fuel Storage Installation (ISFSI) must not exceed 40 years from the date of issuance. Licenses may be renewed by the U.S. Nuclear Regulatory Commission (NRC) at the expiration of the license term upon application by the licensee for a period not to exceed 40 years. Application for ISFSI license renewals must include the following: (1) Time-limited aging analyses (TLAAs) that demonstrate that structures, systems, and components (SSCs) important to safety will continue to perform their intended function for the requested period of extended operation; and (2) a description of the aging management program (AMP) for management of issues associated with aging that could adversely affect SSCs important to safety. In addition, the application must also include design bases information as documented in the most recent updated final safety analysis report as required by 10 CFR 72.70. Information contained in previous applications, statements, or reports filed with the Commission under the license may be incorporated by reference provided that those references are clear and specific. The NRC has recently issued the Standard Review Plan (SRP) for renewal of used-fuel dry cask storage system (DCSS) licenses and Certificates of Compliance (CoCs), NUREG-1927, under which NRC may renew a specific license or a CoC for a term not to exceed 40 years. Both the license and the CoC renewal applications must contain revised technical requirements and operating conditions (fuel storage, surveillance and maintenance, and other requirements) for the ISFSI and DCSS that address aging effects that

Safety aspects of long-term dry interim storage of type-B spent fuel and HLW transport casks

International Nuclear Information System (INIS)

Wolff, D.; Probst, U.; Voelzke, H.; Droste, B.; Roedel, R.

2004-01-01

Based on the German decision to minimise transports of spent fuel casks between nuclear power plants, reprocessing plants and central storage facilities several on-site storage facilities have been licensed till the end of 2003. Because of the large amount of type-B transport casks which are going to be used for long-term interim storage the question of time limited type-B license maintenance during the storage period of up to 40 years has been discussed under different aspects. This paper describes present technical aspects of the discussion. A main aspect of transport cask qualification for interim storage is the long-term behaviour of the metallic seal lid system. Concerning this results from current experimental long-term tests with metallic ''Helicoflex''-seals in which pool water is enclosed are presented. The test series has been performed by the Federal Institute for Materials Research and Testing (BAM) on behalf of the Federal Office for Radiation Protection (BfS) since 2001. Finally, the paper presents a German concept for an authorities' and technical experts' exchange of experience, know-how and state of the art referring to cask dispatch in nuclear facilities. BAM has taken over a central role in this so-called ''co-ordinating institution for cask dispatching information'' (''KOBAF'') which contains an online data base and a technical working group meeting twice a year. The goal is to keep comparable technical standards for all nuclear sites and storage facilities which are going to load and dispatch casks of the same or similar types under the responsibility of different German state governments for the next decades

Advances in Large-Scale Solar Heating and Long Term Storage in Denmark

DEFF Research Database (Denmark)

Heller, Alfred

2000-01-01

According to (the) information from the European Large-Scale Solar Heating Network, (See http://www.hvac.chalmers.se/cshp/), the area of installed solar collectors for large-scale application is in Europe, approximately 8 mill m2, corresponding to about 4000 MW thermal power. The 11 plants...... the last 10 years and the corresponding cost per collector area for the final installed plant is kept constant, even so the solar production is increased. Unfortunately large-scale seasonal storage was not able to keep up with the advances in solar technology, at least for pit water and gravel storage...... of the total 51 plants are equipped with long-term storage. In Denmark, 7 plants are installed, comprising of approx. 18,000-m2 collector area with new plants planned. The development of these plants and the involved technologies will be presented in this paper, with a focus on the improvements for Danish...

Report on the long-term interim storage of spent fuels and vitrified wastes; Gutachten zur Langzeitzwischenlagerung abgebrannter Brennelemente und verglaster Abfaelle

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-12-03

Long-term interim storage for several hundred years is an option on the management of high-level radioactive wastes. The decision on final disposal is postponed. Worldwide the long-term interim storage is not part of the disposal concept - a geologic final repository is the ultimate aim. Using today's technology the interim storage over several hundred years is supposed to be uncritical. Aging management is the most important challenge - the renewal of the facilities would have to be expected. Possible social change and their impact on the interim storage problem has not been considered.

University of Minnesota Aquifer Thermal Energy Storage (ATES) project report on the first long-term cycle

Science.gov (United States)

Walton, M.

1991-10-01

The technical feasibility of high-temperature (greater than 100 C) aquifer thermal energy storage (IOTAS) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota's St. Paul field test facility (FTF). This report describes the additions to the FTF for the long-term cycles and the details of the first long-term cycle (LT1) that was conducted from November 1984 through May 1985. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic aspects of LT1 are reported. The permits for long-term cycles required the addition of a monitoring well 30.5 m from the storage well for monitoring near the edge of the thermally affected area and allowed the addition of a cation-exchange water softener to enable continuous operation during the injection phase. Approximately 62 percent of the 9.47 GWh of energy added to the 9.21 x 10(exp 4) cu m of ground water stored in the aquifer LT1 was recovered. Ion-exchange water softening of the heated and stored ground water prevented scaling in the system heat exchangers and the storage well and changed the major-ion chemistry of the stored water. Temperatures at the storage horizons in site monitoring wells reached as high as 108 C during the injection phase of LT1. Following heat recovery, temperatures were less than 30 C at the same locations. Less permeable horizons underwent slow temperature changes. No thermal or chemical effects were observed at the remote monitoring site.

Loads imposed on dual purpose casks in German on-site-storage facilities for long term intermediate storage of spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Wetzel, N.; Rabe, O. [TUeV NORD EnSys Hannover GmbH und Co. KG, Hanover (Germany)

2004-07-01

In accordance with recent changes of the atomic energy act and in order to secure reliable removal of spent fuel from the nuclear power plants' fuel storage ponds the German utilities filed license applications for a total of 12 onsite- storage facilities for spent fuel assemblies. By the end of 2003 the last of these storage facilities were licensed and are currently under construction. The first on-site-storage facility of that line became operational in late 2002. There are several design lines of storage facilities with different handling procedures or possible accident conditions. Short term interim storage facilities for a few casks are characterized by individual concrete hoods shielding the casks in horizontal position whereas long term intermediate storage facilities currently erected for large numbers of casks typically feature a condensed pattern of casks stored in upright position and massive structures of reinforced concrete. TUeV Hannover/Sachsen-Anhalt e. V. (now TUeV NORD EnSys Hannover GmbH and Co. KG) has been contracted as a body of independent experts for the assessment of all related safety requirements on behalf of the national licensing authority, the federal office for radiation protection (BfS).

Loads imposed on dual purpose casks in German on-site-storage facilities for long term intermediate storage of spent nuclear fuel

International Nuclear Information System (INIS)

Wetzel, N.; Rabe, O.

2004-01-01

In accordance with recent changes of the atomic energy act and in order to secure reliable removal of spent fuel from the nuclear power plants' fuel storage ponds the German utilities filed license applications for a total of 12 onsite- storage facilities for spent fuel assemblies. By the end of 2003 the last of these storage facilities were licensed and are currently under construction. The first on-site-storage facility of that line became operational in late 2002. There are several design lines of storage facilities with different handling procedures or possible accident conditions. Short term interim storage facilities for a few casks are characterized by individual concrete hoods shielding the casks in horizontal position whereas long term intermediate storage facilities currently erected for large numbers of casks typically feature a condensed pattern of casks stored in upright position and massive structures of reinforced concrete. TUeV Hannover/Sachsen-Anhalt e. V. (now TUeV NORD EnSys Hannover GmbH and Co. KG) has been contracted as a body of independent experts for the assessment of all related safety requirements on behalf of the national licensing authority, the federal office for radiation protection (BfS)

New a-Si:H photo-detectors for long-term charge storage

International Nuclear Information System (INIS)

Lee, H.; Cho, G.; Drewery, J.S.; Hong, W.S.; Jing, T.; Kaplan, S.N.; Mireshghi, A.; Perez-Mendez, V.; Wildermuth, D.

1993-04-01

Using the high light absorption properties of amorphous silicon, we developed a new device configuration that can detect photons and store the induced charges for relatively long time. This device, coupled to a scintillator such as CsI(Tl) in an array form, could be used as a scintillation camera, or for long-term photo-detection such as radionuclide labeled chromatography. The detector has a simple sandwich structure consisting of a scintillator followed by a top metal layer, p-i-n layers of hydrogenated amorphous silicon (a-Si:H), a second metal layer, a thin insulating layer and a bottom metal layer. The electron-hole pairs generated in the i-layer by the interaction with the incident light will be separated by the imposed electric field and be stored in the central metal-insulator interface. Readout will be done by switching the external bias to ground after the storage time, which depends on the needs for the specific application. Prototype devices were fabricated and tested. The performances of the devices were analyzed in connection with the storage time and the background signal produced by the thermally generated charges

Development of long term storage technique for recovered Kr-85, (1)

International Nuclear Information System (INIS)

Inada, Eiichi; Motoyama, Shigeji; Tsunoda, Naomi; Yamamoto, Keizo; Hirano, Seiji.

1979-01-01

The adsorption storage method of radioactive krypton Kr-85 using a double cylinder packed with activated charcoal is expected to be put into practical use as an intermediate storing method until the immobilization technique for long term storage is established. In this paper, the conceptual design of an intermediate, remote-controlled Kr-85 storage facility is presented. The features of this system are double containment, low pressure storage, and remote control. Kr-85 is at first filled into a double cylinder by the adsorbing effect of activated charcoal at low temperature (-196 deg C) by cooling with liquid nitrogen. Then, the unwelded portion of the outer cylinder containing the inner cylinder is welded and inspected to make double containment. The double cylinders are cooled by ventilation to remove the decay heat of Kr-85, and krypton leakage is always monitored. If any leakage is detected, the double cylinder is transferred to the cutting cell for the re-encapsulation of Kr-85 in a safe double cylinder. All operations are performed by remote control because of a high radiation field. The expected amount and composition of Kr-85 to be recovered from the reprocessing plant are also given as the design conditions. (Wakatsuki, Y.)

Endogenous BDNF Is Required for Long-Term Memory Formation in the Rat Parietal Cortex

Science.gov (United States)

Alonso, Mariana; Bekinschtein, Pedro, Cammarota, Martin; Vianna, Monica R. M.; Izquierdo, Ivan; Medina, Jorge H.

2005-01-01

Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory…

A long-term stable power supply μDMFC stack for wireless sensor node applications

International Nuclear Information System (INIS)

Wu, Z L; Wang, X H; Teng, F; Li, X Z; Wu, X M; Liu, L T

2013-01-01

A passive, air-breathing 4-cell micro direct methanol fuel cell (μDMFC) stack is presented featured by a fuel delivery structure for a long-term and stable power supply. The fuel is reserved in a T shape tank and diffuses through the porous diffusion layer to the catalyst at anode. The stack has a maximum power output of 110mW with 3M methanol at room temperature and output a stable power even thought 5% fuel is the remained in reservoir. Its performance decreases less than 3% for 100 hours continuous work. As such, it is believed to be more applicable for powering the wireless sensor nodes

Dry oxidation behaviour of metallic containers during long term interim storages

International Nuclear Information System (INIS)

Desgranges, C.; Terlain, A.; Bertrand, N.; Gauvain, D.

2004-01-01

Low-alloyed steels or carbon steels are considered candidate materials for the fabrication of some nuclear waste package containers for long term interim storage. The containers are required to remain retrievable for centuries. One factor limiting their performance on this time scale is corrosion. The estimation of the metal thickness lost by dry oxidation over such long periods requires the construction of reliable models from short-time experimental data. Two complementary approaches for modelling dry oxidation have been considered. First, basic models following simple analytical laws from classical oxidation theories have been adjusted on the apparent activation energy of oxidation deduced from experimental data. Their extrapolation to long oxidation periods confirms that the expected damage due to dry oxidation could be small. Second, a numerical model able to take in consideration several mechanisms controlling the oxide scale growth is under development. Several preliminary results are presented. (authors)

RADIATION SAFETY JUSTIFICATION FOR THE LONG-TERM STORAGE OF GAS CONDENSATE IN THE UNDERGROUND RESERVOURS FORMED BY THE NUCLEAR EXPLOSION TECHNOLOGY

Directory of Open Access Journals (Sweden)

I. K. Romanovich

2010-01-01

Full Text Available The paper presents approaches to the safety justification of the gas condensate and brine long-term storage in the underground reservoirs formed by the nuclear explosion technology. Gas condensate and brine are the intermediate level liquid radioactive waste containing isotopes: 3Н, 137Cs and 90Sr, in traces - 239Pu, 235U, 241Am.Safety of the gas condensate and brine long-term storage in the underground reservoirs is assessed on the base of the multi-barrier principle implementation, used during radioactive waste disposal. It is shown that the gas condensate and brine long-term storage in the sealed underground reservoirs formed by nuclear explosion technologies in salt domes does not lead to the surface radioactive contamination and population exposure.

Changes in chemical quality indices during long-term storage of palm-olein oil under heated storage and transport-type conditions

CSIR Research Space (South Africa)

Van der Merwe, GH

2004-01-15

Full Text Available of Food and Agriculture J Sci Food Agric 84:52?58 (online: 2003) DOI: 10.1002/jsfa.1609 Changes in chemical quality indices during long-term storage of palm-olein oil under heated storage and transport-type conditions Gretel H van der Merwe,1asteriskmath... Lourens M du Plessis1 and John RN Taylor2 1CSIR Bio/Chemtek, PO Box 395, Pretoria 0001, South Africa 2Department of Food Science, University of Pretoria, Pretoria 0002, South Africa Abstract: Six quality indices, namely free fatty acids (FFA), peroxide...

Effect of the long-term memory on the beam break-up instability of a single bunch in storage rings

International Nuclear Information System (INIS)

Pestrikov, D.V.

2009-01-01

We study modifications of the beam break-up instability of transverse coherent oscillations of a single bunch which occur in storage rings due to weak wakefields decaying longer than the revolution period of particles. The long-term part of the wake results in the eigenmode spectra of coherent oscillations. Both stable and unstable modes are found for coherent oscillations of a monochromatic bunch. The single turn wakefields result in the beam break-up coherent oscillations of the bunch. The found eigenmode spectrum does not contain a leading unstable mode. Despite the exponential increase in time of the eigenmodes, both self-consistent and the beam break-up parts of the coherent oscillations indicate similar and non-exponential time dependencies. The beam break-up behavior dominates, if the wake memory is weak.

Corrosion behaviour of metallic containers during long term interim storages

International Nuclear Information System (INIS)

Desgranges, C.; Feron, D.; Mazaudier, F.; Terlain, A.

2001-01-01

Two main corrosion phenomena are encountered in long term interim storage conditions: dry oxidation by the air when the temperature of high level nuclear wastes containers is high enough (roughly higher than 100 C) and corrosion phenomena as those encountered in outdoor atmospheric corrosion when the temperature of the container wall is low enough and so condensation is possible on the container walls. Results obtained with dry oxidation in air lead to predict small damages (less than 1μm on steels over 100 years at 100 C) and no drastic changes with pollutants. For atmospheric corrosion, first developments deal with a pragmatic method that gives assessments of the indoor atmospheric corrosivities. (author)

Safety aspects of long-term dry interim storage of Type B spent fuel and high-level transport casks

International Nuclear Information System (INIS)

Wolff, D.; Probst, U.; Voelzke, H.; Droste, B.; Roedel, R.

2004-01-01

Based on the German decision to minimise transport of spent fuel casks between nuclear power plants, reprocessing plants and central storage facilities several on-site storage facilities were licensed until the end of 2003. Because of the large amount of Type B(U) transport casks which are going to be used for long-term interim storage the question of time-limited Type B(U) licence maintenance during the storage period of up to 40 years has been discussed under different aspects. This paper describes present technical aspects of the discussion. A main aspect of qualification of transport casks for interim storage is the long-term behaviour of the metallic seal-lid system. Here we present results from current long-term experimental tests with metallic 'Helicoflex' seals in which pool water is enclosed. This series of tests has been performed by the Federal Institute for Materials Research and Testing (BAM) on behalf of the Federal Office for Radiation Protection (BfS) since 2001. Finally, the paper presents a German concept for an exchange of experience, know-how and state-of-the-art between authorities and technical experts with regard to cask dispatch in nuclear facilities. BAM has taken over a central role in this so-called 'coordinating institution for cask dispatching information' ('KOBAF') which entails management of an online database of cask-specific documents and a technical working group meeting twice a year. The goal is to keep comparable technical standards for all nuclear sites and storage facilities which are going to load and dispatch casks of the same or similar types under the responsibility of different German state governments for the coming decades. (author)

Safety aspects in the dry storage of spent nuclear fuel in long term operation

Energy Technology Data Exchange (ETDEWEB)

Nodarim, Claudir J.; Silva, Viviane B. da; Fontes, Gladson S. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Saldanha, Pedro L.C., E-mail: claudirnodari@gmail.com, E-mail: vivisborges@gmail.com, E-mail: gsfontes@hotmail.com, E-mail: Saldanha@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2017-07-01

The purpose of the present paper is to discuss the safety assessment of the Dry Storage Unit (DSU), taking into account the long term operation and the operational experience already evidenced in similar facilities. In this sense, the RIDM (Risk-Informed Decision-Making) concept will be adopted for the regulatory decision-making process. Potential technical issues associated with the aging of materials from the dry storage unit will be considered. The work will be done using the rules and requirements of 10 CFR Part 72 and the U.S. NRC (United States Nuclear Regulatory Commission) regulatory guides. (author)

Diverse perspectives on governance on the very long term. Biodiversity, climatic change, CO2 storage, radioactive wastes, space wastes

International Nuclear Information System (INIS)

Boeuf, Gilles; Gouyon, Pierre Henry; Rollinger, Francois; Besnus, Francois; Heriard Dubreuil, Gilles; Dahan, Amy; Alby, Fernand; Arnould, Jacques; Fabriol, Hubert; Hoummady, Moussa; Demarcq, Francois; Farret, Regis; Hubert, Philippe; Weber, Jacques; Charton, Patrick; Boissier, Fabrice; Lopez, Mirelle; Devisse, Jean-Jacques; Mathy, Sandrine; Hourcade, Jean-Charles; Le Roux, Xavier; Bourcier, Danielle; Roure, Francoise; Henry, Claude; Bartet, Jean Hughes; Calame, Mathieu; Biteau, Benoit; Kastler, Guy; Ducret, Pierre; Berest, Pierre; Charron, Sylvie; Clin, Francois; Gadbois, Serge; Gueritte, Michel; Heriard-Dubreuil, Bertrand; Laville, Bettina; Marie, Michel; Marignac, Yves; Ollagnon, Henry; Pelegrin, Flora; Roure, Francoise; Rouyer, Michel; Schellenberger, Thomas; Toussaint, Jean-Francois

2013-03-01

This bibliographical note contains the program of a workshop and a presentation of a book based on the contributions to this workshop proposed by experts, representatives of institutional bodies and associations, or local representatives. This workshop addressed the issue of the governance on the very long term with respect to the management of resources such as climate, geology, biodiversity or space. How to make a possible usage of these resources while ensuring their protection and durability? What are the solutions or new challenges are raising these usages on the very long term? The first part addresses the main challenges and ethical issues for governance on the very long term for each of the examined topics: biodiversity, climatic change, CO 2 storage, radioactive waste storage, and space debris). The next parts propose contributions from different origins and disciplines, present relevant data, and report evidences

Sorption heat storage for long-term low-temperature applications: A review on the advancements at material and prototype scale

NARCIS (Netherlands)

Scapino, L.; Zondag, H.A.; Van Bael, J.; Diriken, J.; Rindt, C.C.M.

2017-01-01

Sorption heat storage has the potential to store large amounts of thermal energy from renewables and other distributed energy sources. This article provides an overview on the recent advancements on long-term sorption heat storage at material- and prototype- scales. The focus is on applications

Monitoring and inspection techniques for long term storage of higher activity waste packages

International Nuclear Information System (INIS)

Bolton, Gary

2013-01-01

In 2009, following recent changes in United Kingdom (UK) Government Policy, the Nuclear Decommissioning Authority (NDA) identified a knowledge gap in the area of long term interim storage of waste packages. A cross-industry Integrated Project Team (IPT) for Interim Storage was created with responsibility for delivering Industry Guidance on the storage of packaged Higher Activity Waste (HAW) for the current UK civil decommissioning and clean-up programmes. This included a remit to direct research and development projects via the NDA's Direct Research Portfolio (DRP) to fill the knowledge gap. The IPT for Interim Storage published Industry Guidance in 2012 which established a method to define generic package performance criteria and made recommendations on monitoring and inspection. The package performance method consists of the following steps; identification of the package safety function, identification of evolutionary processes that may affect safety function performance, determination of measurable indicators of these evolutionary processes and calibration of the indicators into package performance zones. This article provides an overview of three projects funded by the NDA's DRP that the UK National Nuclear Laboratory (NNL) have completed to address monitoring and inspection needs of waste packages in interim storage. (orig.)

Are there long-term benefits in following stable heart failure patients in a heart failure clinic?

DEFF Research Database (Denmark)

Leetmaa, Tina; Villadsen, Henrik; Mikkelsen, Kirsten

2008-01-01

Objectives and Design. This study describes the long-term outcome of 163 patients with stable mild to moderate heart failure (NYHA II-III), who already were enrolled in a heart failure clinic and now were randomized to continued follow-up in the heart failure (HF) clinic or else to usual care (UC...

Verification of geomechanical integrity and prediction of long-term mineral trapping for the Ketzin CO2 storage pilot site

Science.gov (United States)

Kempka, Thomas; De Lucia, Marco; Kühn, Michael

2014-05-01

Static and dynamic numerical modelling generally accompany the entire CO2 storage site life cycle. Thereto, it is required to match the employed models with field observations on a regular basis in order to predict future site behaviour. We investigated the coupled processes at the Ketzin CO2 storage pilot site [1] using a model coupling concept focusing on the temporal relevance of processes involved (hydraulic, chemical and mechanical) at given time-scales (site operation, abandonment and long-term stabilization). For that purpose, long-term dynamic multi-phase flow simulations [2], [3] established the basis for all simulations discussed in the following. Hereby, pressure changes resulting in geomechanical effects are largest during site operation, whereas geochemical reactions are governed by slow kinetics resulting in a long-term stabilization. To account for mechanical integrity, which may be mainly affected during site operation, we incorporated a regional-scale coupled hydro-mechanical model. Our simulation results show maximum ground surface displacements of about 4 mm, whereas shear and tensile failure are not observed. Consequently, the CO2 storage operation at the Ketzin pilot site does not compromise reservoir, caprock and fault integrity. Chemical processes responsible for mineral trapping are expected to mainly occur during long-term stabilization at the Ketzin pilot site [4]. Hence, our previous assessment [3] was extended by integrating two long-term mineral trapping scenarios. Thereby, mineral trapping contributes to the trapping mechanisms with 11.7 % after 16,000 years of simulation in our conservative and with 30.9 % in our maximum reactivity scenarios. Dynamic flow simulations indicate that only 0.2 % of the CO2 injected (about 67,270 t CO2 in total) is in gaseous state, but structurally trapped after 16,000 years. Depending on the studied long-term scenario, CO2 dissolution is the dominating trapping mechanism with 68.9 % and 88

Transmutation technologies to solve the problem of long-term spent nuclear fuel storage

International Nuclear Information System (INIS)

Hosnedl, P.; Valenta, V.; Blahut, O.

2000-01-01

The paper gives a brief description of the transmutation process for actinides and long-lived fission products which are present in spent nuclear fuel. Transmutation technologies can solve the problem of long-term spent nuclear fuel storage and reduce the requirements for storage time and conditions. The basic data and requirements for the detailed design of the transmutor are summarized, and the views upon how to address the fuel purification and dry reprocessing issues are discussed. The results of activities of SKODA JS are highlighted; these include, for instance, the fluoride salt-resistant material MONICR, test loops, and electrowinners. The preliminary design of the transmutor is also outlined. Brief information regarding activities in the field of transmutation technologies in the Czech Republic and worldwide is also presented. The research and design activities to be developed for the whole design of the demonstration and basic units are summarized. It is emphasized that SKODA JS can join in international cooperation without constraints. The Attachment presents a simple assessment of how the radioactivity balance can be reduced, based on the actinide and long-lived fission product transmutation half-lives, is presented in the Attachment. (author)

Characterizing and packaging BN-350 spent fuel for long-term dry storage

International Nuclear Information System (INIS)

Lambert, J. D. B.; Bolshinsky, I.; Haues, S.L.; Allen, K.J.; Howden, E.A.; Hill, R.N.; Planchon, H.P.; Staples, P.; Karaulov, V.N.; Blynskij, A.P.; Yakovlev, I.K.; Maev, V.; Dumchev, I. A.

2000-01-01

The Republic of Kazakhstan is being assisted by the U.S. Department of Energy in preparing spent fuel from the BN-350 fast reactor for long term dry storage. Argonne National Laboratory was assigned responsibility for the physical and nuclear characterization of the spent fuel, for the design and safety analysis of 6-pac and 4-pac canisters used to contain spent fuel assemblies for storage, and for the design, testing and installation of a closure station at the reactor in which the canisters of fuel are dried, filled with inert gas and welded shut. This paper briefly describes the specialized components and equipment used, the process followed, and experience gained in packaging the spent fuel. Olsen et al and Schaefer separately discuss overall safety and criticality considerations of the packaging process in parallel papers to this conference

A neural interface provides long-term stable natural touch perception.

Science.gov (United States)

Tan, Daniel W; Schiefer, Matthew A; Keith, Michael W; Anderson, James Robert; Tyler, Joyce; Tyler, Dustin J

2014-10-08

Touch perception on the fingers and hand is essential for fine motor control, contributes to our sense of self, allows for effective communication, and aids in our fundamental perception of the world. Despite increasingly sophisticated mechatronics, prosthetic devices still do not directly convey sensation back to their wearers. We show that implanted peripheral nerve interfaces in two human subjects with upper limb amputation provided stable, natural touch sensation in their hands for more than 1 year. Electrical stimulation using implanted peripheral nerve cuff electrodes that did not penetrate the nerve produced touch perceptions at many locations on the phantom hand with repeatable, stable responses in the two subjects for 16 and 24 months. Patterned stimulation intensity produced a sensation that the subjects described as natural and without "tingling," or paresthesia. Different patterns produced different types of sensory perception at the same location on the phantom hand. The two subjects reported tactile perceptions they described as natural tapping, constant pressure, light moving touch, and vibration. Changing average stimulation intensity controlled the size of the percept area; changing stimulation frequency controlled sensation strength. Artificial touch sensation improved the subjects' ability to control grasping strength of the prosthesis and enabled them to better manipulate delicate objects. Thus, electrical stimulation through peripheral nerve electrodes produced long-term sensory restoration after limb loss. Copyright © 2014, American Association for the Advancement of Science.

Criteria for recladding of spent light water reactor fuel before long term pool storage

International Nuclear Information System (INIS)

Pettersson, K.; Jansson, L.

1979-01-01

The question of the need for any special treatment of failed fuel elements prior to long term pool storage has been studied. It is concluded that the main problem appears to be hydride embrittlement of failed fuel rods, which may lead to increased damage during handling and transport of the failed fuel. Some mechanisms for the degradation of failed fuel rods have been identified. They can all be considered as relatively improbable, but further experimental evidence is needed before it can be concluded that these degradation mechanisms are insignificant during pool storage. The report also contains a review of methods for identification of leaking fuel bundles and fuel rods. (Auth.)

Criteria for recladding of spent light water reactor fuel before long term pool storage

International Nuclear Information System (INIS)

Pettersson, K.; Jansson, L.

1979-06-01

The question of the need for any special treatment of failed fuel elements prior to long term pool storage has been studied. It is concluded that the main problem appears to be hydride embrittlement of failed fuel rods, which may lead to increased damage during handling and transport of the failed fuel. Some mechanisms for the degradation of failed fuel rods have been identified. They can all be considered as relatively improbable, but further experimental evidence is needed before it can be concluded that thede degradation mechanisms are insignificant during pool storage. The report also contains a review of methods for identification of leaking fuel bundles and fuel rods.(author)

Colour changes in prints during long-term dark storage of prints

International Nuclear Information System (INIS)

Parraman, Carinna

2010-01-01

The most significant impact on colour fading in prints is exposure to light and air. However what happens to coloured prints during long-term storage in boxes, drawers and on shelves? Measurements of samples, printed in July 2005, stored in a range of light and darkened storage conditions have shown some interesting initial results. As more emphasis is placed on the effects of light, the dark stability of inkjet prints is relatively overlooked when considering how to preserve or store coloured prints. This study and presentation builds on previous research [1] and has concentrated on the changes to colour during storage. With reference to ASTM F2035 - 00(2006) Standard Practice for Measuring the Dark Stability of Ink Jet Prints, the Standards outline points out that whilst natural aging is the most reliable method of assessing image stability, materials and inks any data that is produced quickly becomes redundant; therefore accelerated aging is more preferred. However, the fine art materials in this study are still very much in circulation. The leading fine art papers, and pigmented ink-sets used in these trials are still being used by artists. We can therefore demonstrate the characteristics of colour changes and the impact of ink on paper that utilises natural aging methods.

Radiation characteristics of spent nuclear fuel at accumulation in long-term storage

International Nuclear Information System (INIS)

Bergelson, Boris R.; Gerasimov, Aleksander S.

1999-01-01

Time dependence of a decay heat power and radiotoxicity of a single spent nuclear fuel unloading of VVER-1000 reactors at its storage or the same characteristics in accumulation mode with annual addition of spent nuclear fuel in long-term storage are investigated. At calculations of decay heat power, the contributions of alpha-, beta-, and gamma- irradiations were taken into account, at calculations of a radiotoxicity - maximum permissible activity of nuclides in air and in water were taken into account. It is determined that at accumulation less than 100 years, the main contribution to decay heat power is given by fission products, at further storage the power is determined in greater degree by actinides. The radiotoxicity of actinides by air is rich greater than that of fission products - more than 50 times in beginning of a storage and by 2-3 orders of magnitude after 100 and more years. A radiotoxicity of fission products by water at accumulation less than 20 years is a little bit more than actinides, at further accumulation the contribution of fission products decreases. At time of accumulation 100 years, the fission products give the contribution in total radiotoxicity about 40%, at time 1000 years - about 7%. (author)

A Reaction-Diffusion Model for Synapse Growth and Long-Term Memory

Science.gov (United States)

Liu, Kang; Lisman, John; Hagan, Michael

Memory storage involves strengthening of synaptic transmission known as long-term potentiation (LTP). The late phase of LTP is associated with structural processes that enlarge the synapse. Yet, synapses must be stable, despite continual subunit turnover, over the lifetime of an encoded memory. These considerations suggest that synapses are variable-size stable structure (VSSS), meaning they can switch between multiple metastable structures with different sizes. The mechanisms underlying VSSS are poorly understood. While experiments and theory have suggested that the interplay between diffusion and receptor-scaffold interactions can lead to a preferred stable size for synaptic domains, such a mechanism cannot explain how synapses adopt widely different sizes. Here we develop a minimal reaction-diffusion model of VSSS for synapse growth, incorporating the recent observation from super-resolution microscopy that neural activity can build compositional heterogeneities within synaptic domains. We find that introducing such heterogeneities can change the stable domain size in a controlled manner. We discuss a potential connection between this model and experimental data on synapse sizes, and how it provides a possible mechanism to structurally encode graded long-term memory. We acknowledge the support from NSF INSPIRE Award number IOS-1526941 (KL, MFH, JL) and the Brandeis Center for Bioinspired Soft Materials, an NSF MRSEC, DMR- 1420382 (MFH).

Palmitic acid/polypyrrole composites as form-stable phase change materials for thermal energy storage

International Nuclear Information System (INIS)

Silakhori, Mahyar; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Baradaran, Saeid; Naghavi, Mohammad Sajad

2014-01-01

Highlights: • A novel phase change composite of palmitic acid–polypyrrole(PA–PPy) was fabricated. • Thermal properties of PA–PPy are characterized in different mass ratios of PA–PPy. • Thermal cycling test showed that form stable PCM had a favorable thermal reliability. - Abstract: In this study a novel palmitic acid (PA)/polypyrrole (PPy) form-stable PCMs were readily prepared by in situ polymerization method. PA was used as thermal energy storage material and PPy was operated as supporting material. Form-stable PCMs were investigated by SEM (scanning electron microscopy) and FTIR (Fourier transform infrared spectrometer) analysis that illustrated PA Particles were wrapped by PPy particles. XRD (X-ray diffractometer) was used for crystalline phase of PA/PPy composites. Thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) were used for investigating Thermal stability and thermal energy storage properties of prepared form-stable PCMs. According to the obtained results the form stable PCMs exhibited favorable thermal stability in terms of their phase change temperature. The form-stable PCMs (79.9 wt% loading of PA) were considered as the highest loading PCM with desirable latent heat storage of 166.3 J/g and good thermal stability. Accelerated thermal cycling tests also showed that form stable PCM had an acceptable thermal reliability. As a consequence of acceptable thermal properties, thermal stability and chemical stability, we can consider the new kind of form stable PCMs for low temperature solar thermal energy storage applications

Woody debris along an upland chromosequence in boreal Manitoba and its impact on long-term carbon storage

Energy Technology Data Exchange (ETDEWEB)

Manies, K. L.; Harden, J. W. [US Geological Survey, Menlo Park, CA (United States); Bond-Lamberty, B. P. [University of Wisconsin, Dept. of Forest Ecology and Management, Madison, WI (United States); O' Neill, K. P. [USDA Agricultural Research Service, Appalachian Farming Systems Research Center, Beaver, WV (United States)

2005-02-01

The amount of standing dead and downed woody debris along an upland chromosequence was measured in an effort to investigate the role of fire-killed woody debris as a source of soil carbon in black spruce stands in Manitoba. Based on the measurement data and existing primary production values, a mass balance model was used to assess the potential impact of fire-killed wood on long-term carbon storage at this site. Long-term carbon was represented by the amount of carbon stored in deeper soil organic layers, persisting over millenia. Between 10 and 60 per cent of the deep-soil carbon was estimated to have been derived from wood biomass. The actual amount appears to be most affected by fire return interval, decay rate of wood, the amount of net primary production, and the decay rate of the post-fire carbon pool. Although the model was less sensitive to fire consumption rates and to rates at which standing dead wood becomes woody debris, all model runs clearly established that woody debris plays an important role in long-term carbon storage in this area. 53 refs., 4 tabs., 4 figs.

Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

Directory of Open Access Journals (Sweden)

Ternovykh Mikhail

2017-01-01

Full Text Available Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

Science.gov (United States)

Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander

2017-09-01

Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

Qualification of polysiloxanes for long-term storage of radioactive waste

International Nuclear Information System (INIS)

Kucharczyk, P.

2005-12-01

At present German policy envisages interim storage of all radioactive waste (for approximately 30 years) until a final repository is available. This therefore leads to higher standards for storage containers. Silicone elastomers (polysiloxanes), materials on the basis of silicon and oxygen with organic substituents, have various physical and chemical properties and seem to be suitable for the long-term storage of low- and intermediate-level radioactive waste. The aim of the present work is the qualification of a new coating material for storage containers. The use of polysiloxanes in other applications was also investigated. An important criterion for the coating is the simplicity of its application. Moreover, it should also have a high adhesion on steel as well as providing protection against corrosion. These properties were investigated for different polysiloxanes. The spraying tests showed that polysiloxane material with a viscosity of up to 45 000 mPas could be applied by the airless spraying method. An elastic coating was produced which could ensure protection against mechanical impacts. In the framework of water vapour experiments, a very high diffusion constant was determined. The corrosion test confirmed that the polysiloxane coating provided only insufficient corrosion protection if the sample was in contact with water and water vapour at the same time. This problem was solved by using an additional priming coat of 60 μm zinc paint. The adhesion test showed that polysiloxanes have different levels of adhesion. The best adhesion was determined for condensation-cured silicones. The addition-cured materials had a lower adhesion, which was improved by the application of a priming coat. The outcome of these investigations is a wide spectrum of applications for polysiloxanes which can be used as firmly adhering coatings or removable decontamination layers. (orig.)

Thermal behavior of neutron shielding material, NS-4-FR, under long term storage conditions

International Nuclear Information System (INIS)

Yamada, N.; O-iwa, A.; Asano, R.; Horita, R.; Kusunoki, K.

2004-01-01

NS-4-FR, Epoxy-Resin, has been widely used as a neutron shielding material for casks. It is recognized that the resin will degrade during storage and loose weight under high temperature conditions. Most of the examinations for the resin degrading behavior were conducted with rather small bare resin specimens. However, the actual quantity of neutron shielding is quite large and is covered by the cask body. To confirm the degrading behavior of the resin under the long-term storage conditions, we performed the test on the specimen with the same cross-section as the actual design, Hitz B69. The resin test vessels were made out of stainless steel and equipped with flange

Optimization strategies for cask design and container loading in long term spent fuel storage

International Nuclear Information System (INIS)

2006-12-01

As delays are incurred in implementing reprocessing and in planning for geologic repositories, storage of increasing quantities of spent fuel for extended durations is becoming a growing reality. Accordingly, effective management of spent fuel continues to be a priority topic. In response, the IAEA has organized a series of meetings to identify cask loading optimisation issues in preparation for a technical publication on Optimization Strategies for Cask/Container Loading in Long Term Spent Fuel Storage. This publication outlines the optimisation process for cask design, licensing and utilization, describing three principal groups of optimization activities in terms of relevant technical considerations such as criticality, shielding, structural design, operations, maintenance and retrievability. The optimization process for cask design, licensing, and utilization is outlined. The general objectives for the design of storage casks, including storage casks that are intended to be transportable, are summarized. The nature of optimization within the design process is described. The typical regulatory and licensing process is outlined, focusing on the roles of safety regulations, the regulator, and the designer/applicant in the optimization process. Based on the foregoing, a description of the three principal groups of optimization activities is provided. The subsequent chapters of this document then describe the specific optimization activities within these three activity groups, in each of the several design disciplines

Radiolysis of Salts and Long-Term Storage Issues for Both Pure and Impure PuO{sub 2} Materials in Plutonium Storage Containers

Energy Technology Data Exchange (ETDEWEB)

Lav Tandon

2000-05-01

The Material Identification and Surveillance (MIS) project sponsored a literature search on the effects of radiation on salts, with focus on alkali chlorides. The goal of the survey was to provide a basis for estimating the magnitude of {alpha} radiation effects on alkali chlorides that can accompany plutonium oxide (PuO{sub 2}) into storage. Chloride radiolysis can yield potentially corrosive gases in plutonium storage containers that can adversely affect long-term stability. This literature search was primarily done to provide a tutorial on this topic, especially for personnel with nonradiation chemistry backgrounds.

Behaviour of Spent WWER fuel under long term storage conditions

Energy Technology Data Exchange (ETDEWEB)

Kadarmetov, I M [A.A.Bochvar All-Russia Research Institute of Inorganic Materials, Moscow (Russian Federation)

1999-07-02

Results of experimental investigation into thermomechanical properties of pre-irradiated Zr-1%Nb alloy over a range temperatures 500-570 grad C are presented. Safety examination of the Ventilation Storage Casks dry storage system has been carried out. Preliminary safety criteria under dry storage conditions in an environment of inert gas are follows: maximum cladding temperature under normal conditions of dry storage should not exceed 330 grad C after 5-year cooling in water-filled pools; maximum allowable temperature of spent fuel rod cladding under operational mode with infringement of heat removal should not exceed 440 grad C over 8 hours. As each SFA dry storage project comprises its individual technology of spent fuel management, it is necessary to evaluate allowable parameters (terms of storage, maximum temperatures of fuel) for each project respectively. The programme of experimental investigations for the justification of safety criteria for WWER-1000 dry spent fuel storage systems is underway. (author)

Summary report of the screening process to determine reasonable alternatives for long-term storage and disposition of weapons-usable fissile materials

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-29

Significant quantities of weapons-usable fissile materials (primarily plutonium and highly enriched uranium) have become surplus to national defense needs both in the US and Russia. These stocks of fissile materials pose significant dangers to national and international security. The dangers exist not only in the potential proliferation of nuclear weapons but also in the potential for environmental, safety and health consequences if surplus fissile materials are not properly managed. As announced in the Notice of Intent (NOI) to prepare a Programmatic Environmental Impact Statement (PEIS), the Department of Energy is currently conducting an evaluation process for disposition of surplus weapons-usable fissile materials determined surplus to National Security needs, and long-term storage of national security and programmatic inventories, and surplus weapons-usable fissile materials that are not able to go directly from interim storage to disposition. An extensive set of long-term storage and disposition options was compiled. Five broad long-term storage options were identified; thirty-seven options were considered for plutonium disposition; nine options were considered for HEU disposition; and eight options were identified for Uranium-233 disposition. Section 2 discusses the criteria used in the screening process. Section 3 describes the options considered, and Section 4 provides a detailed summary discussions of the screening results.

Summary report of the screening process to determine reasonable alternatives for long-term storage and disposition of weapons-usable fissile materials

International Nuclear Information System (INIS)

1995-01-01

Significant quantities of weapons-usable fissile materials (primarily plutonium and highly enriched uranium) have become surplus to national defense needs both in the US and Russia. These stocks of fissile materials pose significant dangers to national and international security. The dangers exist not only in the potential proliferation of nuclear weapons but also in the potential for environmental, safety and health consequences if surplus fissile materials are not properly managed. As announced in the Notice of Intent (NOI) to prepare a Programmatic Environmental Impact Statement (PEIS), the Department of Energy is currently conducting an evaluation process for disposition of surplus weapons-usable fissile materials determined surplus to National Security needs, and long-term storage of national security and programmatic inventories, and surplus weapons-usable fissile materials that are not able to go directly from interim storage to disposition. An extensive set of long-term storage and disposition options was compiled. Five broad long-term storage options were identified; thirty-seven options were considered for plutonium disposition; nine options were considered for HEU disposition; and eight options were identified for Uranium-233 disposition. Section 2 discusses the criteria used in the screening process. Section 3 describes the options considered, and Section 4 provides a detailed summary discussions of the screening results

Desorption behaviour of polycyclic aromatic hydrocarbons after long-term storage of two harbour sludges from the port of Rotterdam, The Netherlands

KAUST Repository

Heister, Katja; Pols, Sabine; Loch, J. P. Gustav; Bosma, Tom N. P.

2013-01-01

storage time of 14 years at 4 °C under anaerobic conditions in the dark, mimicking depository conditions. Such long-term storage is believed to effect the desorption of the PAHs. Materials and methods: Batch desorption experiments over a time period of 130

LONG-TERM STABLE EQUILIBRIA FOR SYNCHRONOUS BINARY ASTEROIDS

International Nuclear Information System (INIS)

Jacobson, Seth A.; Scheeres, Daniel J.

2011-01-01

Synchronous binary asteroids may exist in a long-term stable equilibrium, where the opposing torques from mutual body tides and the binary YORP (BYORP) effect cancel. Interior of this equilibrium, mutual body tides are stronger than the BYORP effect and the mutual orbit semimajor axis expands to the equilibrium; outside of the equilibrium, the BYORP effect dominates the evolution and the system semimajor axis will contract to the equilibrium. If the observed population of small (0.1-10 km diameter) synchronous binaries are in static configurations that are no longer evolving, then this would be confirmed by a null result in the observational tests for the BYORP effect. The confirmed existence of this equilibrium combined with a shape model of the secondary of the system enables the direct study of asteroid geophysics through the tidal theory. The observed synchronous asteroid population cannot exist in this equilibrium if described by the canonical 'monolithic' geophysical model. The 'rubble pile' geophysical model proposed by Goldreich and Sari is sufficient, however it predicts a tidal Love number directly proportional to the radius of the asteroid, while the best fit to the data predicts a tidal Love number inversely proportional to the radius. This deviation from the canonical and Goldreich and Sari models motivates future study of asteroid geophysics. Ongoing BYORP detection campaigns will determine whether these systems are in an equilibrium, and future determination of secondary shapes will allow direct determination of asteroid geophysical parameters.

[Long-term storage of obligate anaerobic microorganisms in glycerol].

Science.gov (United States)

Briukhanov, A I; Netrusov, A I

2006-01-01

We evaluated the possibility of storing the cultures of obligate anaerobic microorganisms (clostridia. acetogenic and sulfate-reducing bacteria, and methanogenic archaea) in 25% glycerol at -70 degrees C for a long time (up to 3 years). This method of storage is adequate to preserve cell viability in most obligate anaerobes.

The TDR: A Repository for Long Term Storage of Geophysical Data and Metadata

Science.gov (United States)

Wilson, A.; Baltzer, T.; Caron, J.

2006-12-01

For many years Unidata has provided easy, low cost data access to universities and research labs. Historically Unidata technology provided access to data in near real time. In recent years Unidata has additionally turned to providing middleware to serve longer term data and associated metadata via its THREDDS technology, the most recent offering being the THREDDS Data Server (TDS). The TDS provides middleware for metadata access and management, OPeNDAP data access, and integration with the Unidata Integrated Data Viewer (IDV), among other benefits. The TDS was designed to support rolling archives of data, that is, data that exist only for a relatively short, predefined time window. Now we are creating an addition to the TDS, called the THREDDS Data Repository (TDR), which allows users to store and retrieve data and other objects for an arbitrarily long time period. Data in the TDR can also be served by the TDS. The TDR performs important functions of locating storage for the data, moving the data to and from the repository, assigning unique identifiers, and generating metadata. The TDR framework supports pluggable components that allow tailoring an implementation for a particular application. The Linked Environments for Atmospheric Discovery (LEAD) project provides an excellent use case for the TDR. LEAD is a multi-institutional Large Information Technology Research project funded by the National Science Foundation (NSF). The goal of LEAD is to create a framework based on Grid and Web Services to support mesoscale meteorology research and education. This includes capabilities such as launching forecast models, mining data for meteorological phenomena, and dynamic workflows that are automatically reconfigurable in response to changing weather. LEAD presents unique challenges in managing and storing large data volumes from real-time observational systems as well as data that are dynamically created during the execution of adaptive workflows. For example, in order to

Winery wastewater treatment by a combined process: long term aerated storage and Fenton's reagent.

Science.gov (United States)

Lucas, Marco S; Mouta, Maria; Pirra, António; Peres, José A

2009-01-01

The degradation of the organic pollutants present in winery wastewater was carried out by the combination of two successive steps: an aerobic biological process followed by a chemical oxidation process using Fenton's reagent. The main goal of this study was to evaluate the temporal characteristics of solids and chemical oxygen demand (COD) present in winery wastewater in a long term aerated storage bioreactor. The performance of different air dosage daily supplied to the biologic reactor, in laboratory and pilot scale, were examined. The long term hydraulic retention time, 11 weeks, contributed remarkably to the reduction of COD (about 90%) and the combination with the Fenton's reagent led to a high overall COD reduction that reached 99.5% when the mass ratio (R = H(2)O(2)/COD) used was equal to 2.5, maintaining constant the molar ratio H(2)O(2)/Fe(2+)=15.

Implications of alpha-decay for long term storage of advanced heavy water reactor fuels

International Nuclear Information System (INIS)

Pencer, J.; McDonald, M.H.; Roubtsov, D.; Edwards, G.W.R.

2017-01-01

Highlights: •Alpha decays versus storage time are calculated for examples of advanced heavy water reactor fuels. •Estimates are made for fuel swelling and helium bubble formation as a function of time. •These predictions are compared to predictions for natural uranium fuel. •Higher rates of damage are predicted for advanced heavy water reactor fuels than natural uranium. -- Abstract: The decay of actinides such as 238 Pu, results in recoil damage and helium production in spent nuclear fuels. The extent of the damage depends on storage time and spent fuel composition and has implications for the integrity of the fuels. Some advanced nuclear fuels intended for use in pressurized heavy water pressure tube reactors have high initial plutonium content and are anticipated to exhibit swelling and embrittlement, and to accumulate helium bubbles over storage times as short as hundreds of years. Calculations are performed to provide estimates of helium production and fuel swelling associated with alpha decay as a function of storage time. Significant differences are observed between predicted aging characteristics of natural uranium and the advanced fuels, including increased helium concentrations and accelerated fuel swelling in the latter. Implications of these observations for long term storage of advanced fuels are discussed.

Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

International Nuclear Information System (INIS)

Bera, Susanta; Khan, Hasmat; Biswas, Indranil; Jana, Sunirmal

2016-01-01

Highlights: • Polyaniline (PANI) hybridized ZnO nanorods was synthesized by solution method. • Surface defects were found in the nanorods. • The hybrid material exhibited an enhancement in visible light absorption. • A long-term stable photoelectrochemical activity of the material was found. • Advancement in the properties would be PANI hybridization and surface defects. - Abstract: We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV–vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors

Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

Energy Technology Data Exchange (ETDEWEB)

Bera, Susanta; Khan, Hasmat [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India); Biswas, Indranil [Materials Characterization and Instrumentation Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India); Jana, Sunirmal, E-mail: sjana@cgcri.res.in [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India)

2016-10-15

Highlights: • Polyaniline (PANI) hybridized ZnO nanorods was synthesized by solution method. • Surface defects were found in the nanorods. • The hybrid material exhibited an enhancement in visible light absorption. • A long-term stable photoelectrochemical activity of the material was found. • Advancement in the properties would be PANI hybridization and surface defects. - Abstract: We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV–vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors

Influence of high burnup on the decay heat power of spent fuel at long-term storage

International Nuclear Information System (INIS)

Bergelson, B.; Gerasimov, A.; Tikhomirov, G.

2005-01-01

Development and application of advanced fuel with higher burnup is now in practice of NPP with light water reactors in an increasing number of countries. High burnup allows to decrease significantly consumption of uranium. However, spent fuel of this type contains increased amount of high active actinides and fission products in comparison with spent fuel of common-type burnup. Therefore extended time of storage, improved cooling system of the storage facility will be required along with more strong radiation protection during storage, transportation and processing. Calculated data on decay heat power of spent uranium fuel of light water VVER-1000 type reactor are discussed in the paper. Long-term storage of discharged fuel during 100000 years is considered. Calculations were made for burnups of 40-70 MW d/kg. In the initial 50-year period of storage, power of fission products is much higher than that of actinides. Power of gamma-radiation is mainly due to fission products. During subsequent storage power of fission products quickly decreases, the main contribution to the power is given by actinides rather than by fission products. (author)

Long-term storage of recovered krypton

International Nuclear Information System (INIS)

Horii, Yuji; Yamamoto, Yoshimasa

1983-01-01

Various storage methods for krypton-85 recovered from a nuclear fuel reprocessing plant are under development in many countries. These methods include:(1) direct storage in pressurized cylinders, (2) storage of krypton adsorbed on charcoal or zeolite in pressurized cylinders and (3) immobilization (encapsulation) in zeolite. A krypton storage facility using pressurized cylinders has been constructed in the krypton recovery pilot plant in Tokaimura and other methods are now under development. These three methods are evaluated and the features of the constructed facility are also reported. (author)

Long-term storage of irradiated potatoes for use in processed products, (2)

International Nuclear Information System (INIS)

Aoki, Shohei; Umeda, Keiji; Kameyama, Keiji.

1982-01-01

Effect of reconditioning of irradiated potatoes on the decrease of reducing sugar was studied. As a result, a suitable storage condition to maintain the desirable processing properties is proposed. The reducing sugar content was temporarily increased by irradiation at the early or last period of dormancy. The increase of reducing sugar was easily suppressed at the early period of dormancy by reconditioning immediately after irradiation. Reducing sugar did not decrease by the reconditioning when the irraditaion was carried out the early period of dormancy, but decreased when carried out at the last period of dormancy. A desirable procedure to maintain the processing properties of irradiated potatoes is as follows: Harvest the potatoes, store in bulk or containers and cure for 10 days at 10 0 C, RH90%. Irradiate the cured potatoes and recondition for 2 weeks under 15 0 C and RH80%. Long-term storage is then carried out at 7 - 8 0 C. Before processing, recondition the stored potatoes for 2 to 4 weeks at 15 0 C and RH 80%. (author)

Effect of Endodontic Irrigants on Microtensile Bond Strength to Dentin After Thermocycling and Long-Term Water Storage

Directory of Open Access Journals (Sweden)

Daniel Galafassi

2013-01-01

Full Text Available Objective: The bond strength of adhesives in irrigated dentin behaves differently over time. The aim of this study was to evaluate the influence of long-term water storage and thermocycling on the microtensile bond strength of adhesive systems to dentin irrigated with endodontic solutions.Materials and Methods: Sixty human molars were used after removal of the occlusal portion and exposure of the dentin by grinding. The specimens were irrigated with 2.5% NaOCl for 30 minutes and then 17% EDTA for 5 minutes and assigned to six groups according to the adhesive system (n=10: G1 and G2–Clearfil SE Bond; G3 and G4–Single Bond 2; and G5 and G6–XP Bond. The teeth were restored with composite and were subjected to water storage for different time periods. G1, G3 and G5 were stored for 24 h; G2, G4 and G6 were stored for 6 months and were subjected to thermocycling (12,000 cycles, 5°C to 55°C, 500 cycles per week for 6 months. After storage, the tooth/restoration assembly was sectioned to obtain four sticks of approximately 1 mm2, for microtensile bond strength testing. The results were analyzed by two-way ANOVA and Tukey’s test.Results: Significant differences were observed among the adhesives (p<0.01. No significant differences were observed in the microtensile bond strength between samples after 24 hours of storage without thermocycling and after 6-month storage with 12,000 cycles (p<0.05.Conclusion: The bond strengths of G5 and G6 after irrigation with 2.5% NaOCl and 17% EDTA were significantly different from those of other groups. Long-term water storage/thermocycling had no effect on bond strength to dentin.

Key Performance Criteria Affecting the Most the Safety of a Nuclear Waste Long Term Storage : A Case Study Commissioned by CEA

Energy Technology Data Exchange (ETDEWEB)

Marvy, A.; Lioure, A; Heriard-Dubreuil, G.; Gadbois, S.; Schneider, T.; Schieber, C.

2003-02-24

As part of the work scope set in the French law on high level long lived waste R&D passed in 1991, CEA is conducting a research program to establish the scientific basis and assess the feasibility of long term storage as an option for the safe management of nuclear waste for periods as long as centuries. This goal is a significant departure from the current industrial practice where storage facilities are usually built to last only a few decades. From a technical viewpoint such an extension in time seems feasible provided care and maintenance is exercised. Considering such long periods of time, the risk for Society of loosing oversight and control of such a facility is real, which triggers the question of whether and how long term storage safety can be actually achieved. Therefore CEA commissioned a study (1) in which MUTADIS Consultants (2) and CEPN (3) were both involved. The case study looks into several past and actual human enterprises conducted over significant periods o f time, one of them dating back to the end of the 18th century, and all identified out of the nuclear field. Then-prevailing societal behavior and organizational structures are screened out to show how they were or are still able to cope with similar oversight and control goals. As a result, the study group formulated a set of performance criteria relating to issues like responsibility, securing funds, legal and legislative implications, economic sustainable development, all being areas which are not traditionally considered as far as technical studies are concerned. These criteria can be most useful from the design stage onward, first in an attempt to define the facility construction and operating guiding principles, and thereafter to substantiate the safety case for long term storage and get geared to the public dialogue on that undertaking should it become a reality.

Key Performance Criteria Affecting the Most the Safety of a Nuclear Waste Long Term Storage : A Case Study Commissioned by CEA

International Nuclear Information System (INIS)

Marvy, A.; Lioure, A; Heriard-Dubreuil, G.; Gadbois, S.; Schneider, T.; Schieber, C.

2003-01-01

As part of the work scope set in the French law on high level long lived waste R and D passed in 1991, CEA is conducting a research program to establish the scientific basis and assess the feasibility of long term storage as an option for the safe management of nuclear waste for periods as long as centuries. This goal is a significant departure from the current industrial practice where storage facilities are usually built to last only a few decades. From a technical viewpoint such an extension in time seems feasible provided care and maintenance is exercised. Considering such long periods of time, the risk for Society of loosing oversight and control of such a facility is real, which triggers the question of whether and how long term storage safety can be actually achieved. Therefore CEA commissioned a study (1) in which MUTADIS Consultants (2) and CEPN (3) were both involved. The case study looks into several past and actual human enterprises conducted over significant periods o f time, one of them dating back to the end of the 18th century, and all identified out of the nuclear field. Then-prevailing societal behavior and organizational structures are screened out to show how they were or are still able to cope with similar oversight and control goals. As a result, the study group formulated a set of performance criteria relating to issues like responsibility, securing funds, legal and legislative implications, economic sustainable development, all being areas which are not traditionally considered as far as technical studies are concerned. These criteria can be most useful from the design stage onward, first in an attempt to define the facility construction and operating guiding principles, and thereafter to substantiate the safety case for long term storage and get geared to the public dialogue on that undertaking should it become a reality

Image storage and permanence considerations in the long-term preservation of photographic images - update 2010

International Nuclear Information System (INIS)

LaBarca, Joseph E

2010-01-01

Archivists and consumers, alike, need to become aware of long-term storage and preservation issues that relate to the preservation of the data behind digital photographic images. The more obvious issues, such as accidental or catastrophic data loss and hardware format evolution, are only now being recognized in the archiving community. Consumers need to be alerted to these issues and be prepared to develop preservation strategies as well. However, longer-term issues beyond routine backup and migration of data need to be considered. The very basic solution of preservation via hardcopy images stored in shoeboxes or albums is one option, but this raises a fundamental question regarding image preservation that transcends even the more complex solutions-the long-term stability of the chosen media, whether digital or analog. This paper discusses archiving and preservation as it relates to images, and the data behind those images, along with historical perspectives and an overview of possible longer-term preservation strategies. The importance of image permanence standards, as they relate to overall selection of preservation strategies, will also be discussed.

IFNy+ and IFNy- Treg subsets with stable and unstable Foxp3 expression in kidney transplant recipients with good long-term graft function.

Science.gov (United States)

Trojan, Karina; Unterrainer, Christian; Aly, Mostafa; Zhu, Li; Weimer, Rolf; Bulut, Nuray; Morath, Christian; Opelz, Gerhard; Daniel, Volker

2016-10-29

Treg are a heterogenous cell population. In the present study we attempted to identify Treg subsets that might contribute to stable and good long-term graft function. Lymphocyte and Treg subsets were studied in 136 kidney transplant recipients with good long-term graft function and in 52 healthy control individuals using eight-color-fluorescence flow cytometry. Foxp3 TSDR methylation status was investigated in enriched IFNy+ and IFNy- Treg preparations using high resolution melt analysis. Compared with healthy controls, patients showed strong associations of IFNy secreting Helios+ and Helios- Treg with Treg that co-expressed perforin and/or CTLA4 (CD152; pterm graft function possess IFNy+ and IFNy- Treg with stable and unstable Foxp3 expression in the blood. They co-express CD28, HLADR, CTLA4, CXCR3, Lselectin, TGFβ, perforin and FasL and might contribute to the establishment and maintenance of good long-term graft function. Copyright © 2016. Published by Elsevier B.V.

Development of Integrity Evaluation Technology for the Long-term Spent Fuel Dry Storage System (1st year Report)

International Nuclear Information System (INIS)

Choi, Jong Won; Kook, Dong Hak; Kim, Jun Sub

2010-05-01

Korea has operated 16 Pressurized Water Reactors(PWR) and has a plan to construct additional nuclear power reactors as only PWR. This causes a big issue of PWR spent fuel accumulation problem now and in the future. KRMC(Korea Radioactive waste Management Coorporation) which was established in 2009 is charged with managing all kinds of radioactive waste that is produced in Korea. KRMC is considering spent fuel dry storage as an option to solve this spent fuel problem and developing the related engineering techniques. KAERI(Korea Atomic Energy Research Institute) also participated in this development and focused on evaluating the spent fuel dry storage system integrity for a long term operation. This report is the first year research product. The aims of the first year work scope are surveying and analyzing models which could anticipate degradation phenomena of the all dry storage components(spent fuel, structure materials, and equipment materials) and selecting items of the tests which are planned to perform in the next project stage. The major work areas consist of 'spent fuel degradation evaluation model development', 'test senario development', 'long-term evaluation of structural material characteristics', and 'dry storage system structure degradation model development'. These works were successfully achieved. This report is expected to contribute for the second year work which includes degradation model development and test senario development, and next project stage

Seed quality preservation advantage of gamma irradiation seed pre-treatment during long term storage in soybean

International Nuclear Information System (INIS)

Guha, Sameer Kumar; Sumedha; Singh, Bhupinder

2014-01-01

The experiment was conducted to analyse the effect of gamma irradiation seed pre-treatment on insect damage and quality preservation of soybean seeds during long term storage at ambient temperature (27-42 ℃) and relative humidity (50-95%). Freshly harvested seeds of soybean (cv. Pusa-9814) were treated with control (0), 0.01, 0.05, 0.5, 1.0, 3.0, 5.0 kGy gamma radiation on a Gamma irradiator (Gamma Chamber 5000, 60 Co source, activity 12000 Ci, BRIT, Mumbai, India) at the Nuclear Research Laboratory, IARI, New Delhi and were stored over one year in cotton cloth bags under ambient conditions. Protein and oil per cent and fatty acid profile was measured in freshly harvested zero time unirradiated control, aged unirradiated control and other treatments of ionizing radiation. Seed oil was extracted through the soxhlet extraction method and oil profiling was done by gas chromatography. Change in saturated and unsaturated fatty acids like palmitic, stearic, oleic, linolic, linolenic acid and oleic to linoleic ratio was measured. Oil content of unirradiated stored seeds compared to that of the freshly harvested control was lower. However, radiation in general, helped in maintaining a higher seed oil during storage when compared with that of the aged unirradiated control and was insignificantly reduced over the fresh unirrradiated control. Further, gamma irradiation treatment did not yield any adverse affect on the seed protein even after prolonged storage. The results reveal a reduced rate of lipid degradation and improved seed hardness over untreated control with no significant change in fatty acid profile of the irradiated and the unirradiated seeds over a long term storage period. (author)

Issues at stake when considering long term storage of HLW. A comprehensive approach to designing the facility

International Nuclear Information System (INIS)

Marvy, A.; Ochem, D.

2002-01-01

CEA has been conducting a comprehensive R and D program to identify and study key HLW storage design criteria to possibly meet the lifetime goal of a century and beyond. A novel approach is being used since such installations must be understood as a global system comprised of various materials and hardware components, canisters, concrete and steel structures and specific procedures covering engineering steps from construction to operation including monitoring, care and maintenance as well as licensing. The challenge set by such a lifetime design goal made the R and D people focus on issues at stake and relevant to long term HLW storage in particular heat management, the effect of time on materials and the sustainability of care and maintenance. This opened up the R and D field from fundamental research areas to more conventional and technical aspects. Two major guiding principles have been devised as key design goals for the storage concepts under consideration. One is the paramount function of retrievability, which must allow the safe retrieval of any HLW package from the facility at any given time. Next is the passive containment philosophy requiring that a two-barrier system be considered. In the case of spent fuel, CEA's early assessment of the long-term behaviour of cladding shows that it cannot qualify as a reliable barrier over a long period of time. Therefore, the overriding strategy of preventing corrosion and material degradation to achieve canister protection, and therefore containment of radioactive material throughout the time of period envisaged, is at the heart of the R and D program and several design alternatives are being studied to meet that objective. For instance available thermal power from SF is used to establish dry corrosion conditions within the storage facility. The paper reviews all of these different R and D and engineering aspects. (author)

The essential conditions for the choice of location for a long-term storage of radioactive wastes

International Nuclear Information System (INIS)

Markovic, V.

1964-10-01

The paper deals with a long-term storage of radioactive wastes with a special reference to the parameters to be considered in choosing the location. It gives a short account of methods for disposal of radioactive liquid and solid wastes used in nuclear centers in the world. The possibilities of radioactive wastes disposal in our country using the methods investigated are also presented (author)

microRNA Biomarker Discovery and High-Throughput DNA Sequencing Are Possible Using Long-term Archived Serum Samples.

Science.gov (United States)

Rounge, Trine B; Lauritzen, Marianne; Langseth, Hilde; Enerly, Espen; Lyle, Robert; Gislefoss, Randi E

2015-09-01

The impacts of long-term storage and varying preanalytical factors on the quality and quantity of DNA and miRNA from archived serum have not been fully assessed. Preanalytical and analytical variations and degradation may introduce bias in representation of DNA and miRNA and may result in loss or corruption of quantitative data. We have evaluated DNA and miRNA quantity, quality, and variability in samples stored up to 40 years using one of the oldest prospective serum collections in the world, the Janus Serumbank, a biorepository dedicated to cancer research. miRNAs are present and stable in archived serum samples frozen at -25°C for at least 40 years. Long-time storage did not reduce miRNA yields; however, varying preanalytical conditions had a significant effect and should be taken into consideration during project design. Of note, 500 μL serum yielded sufficient miRNA for qPCR and small RNA sequencing and on average 650 unique miRNAs were detected in samples from presumably healthy donors. Of note, 500 μL serum yielded sufficient DNA for whole-genome sequencing and subsequent SNP calling, giving a uniform representation of the genomes. DNA and miRNA are stable during long-term storage, making large prospectively collected serum repositories an invaluable source for miRNA and DNA biomarker discovery. Large-scale biomarker studies with long follow-up time are possible utilizing biorepositories with archived serum and state-of-the-art technology. ©2015 American Association for Cancer Research.

Reinstatement of long-term memory following erasure of its behavioral and synaptic expression in Aplysia.

Science.gov (United States)

Chen, Shanping; Cai, Diancai; Pearce, Kaycey; Sun, Philip Y-W; Roberts, Adam C; Glanzman, David L

2014-11-17

Long-term memory (LTM) is believed to be stored in the brain as changes in synaptic connections. Here, we show that LTM storage and synaptic change can be dissociated. Cocultures of Aplysia sensory and motor neurons were trained with spaced pulses of serotonin, which induces long-term facilitation. Serotonin (5HT) triggered growth of new presynaptic varicosities, a synaptic mechanism of long-term sensitization. Following 5HT training, two antimnemonic treatments-reconsolidation blockade and inhibition of PKM--caused the number of presynaptic varicosities to revert to the original, pretraining value. Surprisingly, the final synaptic structure was not achieved by targeted retraction of the 5HT-induced varicosities but, rather, by an apparently arbitrary retraction of both 5HT-induced and original synapses. In addition, we find evidence that the LTM for sensitization persists covertly after its apparent elimination by the same antimnemonic treatments that erase learning-related synaptic growth. These results challenge the idea that stable synapses store long-term memories.

Long-term potentiation and long-term depression: a clinical perspective

Directory of Open Access Journals (Sweden)

Timothy V.P. Bliss

2011-01-01

Full Text Available Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke.

Comparative neurocognitive effects of lithium and anticonvulsants in long-term stable bipolar patients.

Science.gov (United States)

Sabater, Ana; García-Blanco, Ana C; Verdet, Hélade M; Sierra, Pilar; Ribes, Josep; Villar, Irene; Lara, Mª José; Arnal, Pilar; Rojo, Luis; Livianos, Lorenzo

2016-01-15

The aim of choosing a mood-stabilizing drug (lithium or anticonvulsants) or a combination of them with minimal neurocognitive effects is to stimulate the development of criteria for a therapeutic adequacy, particularly in Bipolar Disorder (BD) patients who are clinically stabilized. Three groups of BD patients were established according to their treatment: (i) lithium monotherapy (n=29); (ii) lithium together with one or more anticonvulsants (n=28); and (iii) one or more anticonvulsants (n=16). A group of healthy controls served as the control (n=25). The following tests were applied: Wechsler Adult Intelligence Scale, Trail Making Test, Wechsler Memory Scale, Rey Complex Figure Test, Stroop color-word test, Wisconsin Card Sorting Test, Tower of Hanoi, Frontal Assessment Battery, and Reading the Mind in the Eyes Test. Relative to healthy controls, BD patients showed the following: (i) those on lithium monotherapy, but not other BD groups, had preserved short-term auditory memory, long-term memory, and attention; (ii) those who took only anticonvulsants showed worse findings in short-term visual memory, working memory, and several executive functions; and (iii) all BD patients showed worse performance in processing speed, resistance to interference, and emotion recognition. Medication alone cannot explain why all BD patients showed common cognitive deficits despite different pharmacological treatment. The impairment on some executive functions and emotion recognition is an inherent trait in BD patients, regardless of their pharmacological treatment. However, while memory, attention, and most of the executive functions are preserved in long-term stable BD patients, these cognitive functions are impaired in those who take anticonvulsants. Copyright © 2015. Published by Elsevier B.V.

Towards long-term stable solid state electrolyzers with infiltrated catalysts

DEFF Research Database (Denmark)

Ovtar, Simona; Chen, Ming; Brodersen, Karen

conventional power plants or fuel cells. Key challenges for a successful commercialization of solid oxide electrolyzers are up scale it, reduce cost and improve durability. Therefore, large efforts are allocated to improve cell performance. As a relatively novel method to introduce electro......Renewable energy sources like wind and solar are widely considered as the key technologies to cover our growing demands. However, the fluctuating nature of these sources requires a flexible energy system and storage technologies to ensure that energy supply can be covered in a stable and affordable......-catalysts into the porous structure of the electrodes, infiltration has shown very efficient. Solid oxide cells with infiltrated electrodes have been reported to show improved performance compared to conventional cells [1]. In this study, the development of infiltration procedures to improve the stability and catalytic...

Visual long-term memory has a massive storage capacity for object details.

Science.gov (United States)

Brady, Timothy F; Konkle, Talia; Alvarez, George A; Oliva, Aude

2008-09-23

One of the major lessons of memory research has been that human memory is fallible, imprecise, and subject to interference. Thus, although observers can remember thousands of images, it is widely assumed that these memories lack detail. Contrary to this assumption, here we show that long-term memory is capable of storing a massive number of objects with details from the image. Participants viewed pictures of 2,500 objects over the course of 5.5 h. Afterward, they were shown pairs of images and indicated which of the two they had seen. The previously viewed item could be paired with either an object from a novel category, an object of the same basic-level category, or the same object in a different state or pose. Performance in each of these conditions was remarkably high (92%, 88%, and 87%, respectively), suggesting that participants successfully maintained detailed representations of thousands of images. These results have implications for cognitive models, in which capacity limitations impose a primary computational constraint (e.g., models of object recognition), and pose a challenge to neural models of memory storage and retrieval, which must be able to account for such a large and detailed storage capacity.

The Safety Assessment of Long term Interim Storage at Sellafield

International Nuclear Information System (INIS)

Buchan, Andrew B.

2014-01-01

that are most significant in terms of frequency and unmitigated potential consequences PSA looks at the full range of fault sequences and allows full incorporation of the reliability and failure probability of the safety measures and other features of the design and operations SAA considers significant but unlikely accidents where off-site consequences are likely to significantly affect the critical group and provides information on their progression, within the facility and also beyond the site boundary. The paper will illustrate how these techniques have been utilised to facilitate design, operation, resilience evaluation and accident management of facilities supporting long term interim storage at Sellafield. (author)

Use of information-retrieval languages in automated retrieval of experimental data from long-term storage

Science.gov (United States)

Khovanskiy, Y. D.; Kremneva, N. I.

1975-01-01

Problems and methods are discussed of automating information retrieval operations in a data bank used for long term storage and retrieval of data from scientific experiments. Existing information retrieval languages are analyzed along with those being developed. The results of studies discussing the application of the descriptive 'Kristall' language used in the 'ASIOR' automated information retrieval system are presented. The development and use of a specialized language of the classification-descriptive type, using universal decimal classification indices as the main descriptors, is described.

Long-Term Outcomes of Laser Prostatectomy for Storage Symptoms: Comparison of Serial 5-Year Followup Data between High Performance System Photoselective Vaporization and Holmium Laser Enucleation of the Prostate.

Science.gov (United States)

Cho, Min Chul; Song, Won Hoon; Park, Juhyun; Cho, Sung Yong; Jeong, Hyeon; Oh, Seung-June; Paick, Jae-Seung; Son, Hwancheol

2018-01-09

We compared long-term storage symptom outcomes between photoselective laser vaporization of the prostate with a 120 W high performance system and holmium laser enucleation of the prostate. We also determined factors influencing postoperative improvement of storage symptoms in the long term. Included in our study were 266 men, including 165 treated with prostate photoselective laser vaporization using a 120 W high performance system and 101 treated with holmium laser enucleation of the prostate, on whom 60-month followup data were available. Outcomes were assessed serially 6, 12, 24, 36, 48 and 60 months postoperatively using the International Prostate Symptom Score, uroflowmetry and the serum prostate specific antigen level. Postoperative improvement in storage symptoms was defined as a 50% or greater reduction in the subtotal storage symptom score at each followup visit after surgery compared to baseline. Improvements in frequency, urgency, nocturia, subtotal storage symptom scores and the quality of life index were maintained up to 60 months after photoselective laser vaporization or holmium laser enucleation of the prostate. There was no difference in the degree of improvement in storage symptoms or the percent of patients with postoperative improvement in storage symptoms between the 2 groups throughout the long-term followup. However, the holmium laser group showed greater improvement in voiding symptoms and quality of life than the laser vaporization group. On logistic regression analysis a higher baseline subtotal storage symptom score and a higher BOOI (Bladder Outlet Obstruction Index) were the factors influencing the improvement in storage symptoms 5 years after prostate photoselective laser vaporization or holmium laser enucleation. Our serial followup data suggest that storage symptom improvement was maintained throughout the long-term postoperative period for prostate photoselective laser vaporization with a 120 W high performance system and holmium

Compact approach to long-term monitored retrievable storage of spent fuel

International Nuclear Information System (INIS)

Muir, D.W.

1986-01-01

We examine a new approach to monitored retrievable storage (MRS) that is extremely compact in terms of total land use and may offer increased security and reduced environmental impact, relative to current designs. This approach involves embedding the spent fuel assemblies in monolithic blocks of metallic aluminum. While this would clearly require increased effort in the spent-fuel packaging phase, it would offer in return the above-mentioned environmental advantages, plus the option of easily extending the surface-storage time scale from several years to several decades if a need for longer storage times should arise in the future

Pore-filled electrolyte membranes for facile fabrication of long-term stable dye-sensitized solar cells

International Nuclear Information System (INIS)

Seo, Seok-Jun; Cha, Hyeon-Jung; Kang, Yong Soo; Kang, Moon-Sung

2015-01-01

Graphical abstract: Display Omitted -- Highlights: •Pore-filled film electrolytes (PFEMs) were investigated for facile DSSC fabrication. •Optimal mixed solvent was suggested to enhance the long-term stability of DSSCs. •The PFEMs promised both the excellent thermal stability and energy efficiency. •Thephotovoltaic efficiency was well correlated with porous structure of substrates. -- ABSTRACT: Pore-filled electrolyte membranes (PFEMs) have been prepared by employing an optimized porous substrate and stable electrolyte composition for a facile manufacturing process of dye-sensitized solar cells (DSSCs). The PFEMs could be easily loaded into a photovoltaic device without adding a traditional electrolyte injection through a hole. In order to meet the requirements of both high energy conversion efficiency and proper long-term stability, three different solvents with high boiling point, i.e. valeronitrile, dimethyl sulfoxide, and dimethylacetamide, were appropriately mixed as a volumetric ratio of 7:2:1, respectively. As a result, similar conductivity and viscosity as well as better chemical stability were obtained compared to those of conventional 3-methoxypropionitrile-based electrolyte. In addition, linear relations were observed between the photovoltaic efficiency and porous film properties (i.e. porosity and tortuosity). The DSSC employing the PFEM doped with the mixed solvent based electrolyte exhibited the photon-to-current conversion efficiency of 6.30% at one sun condition. Moreover, the long-term stability test fixed at an elevated temperature of 85 °C exhibited outstanding durability of DSSC for 500 h

Investigation on polyetheretherketone composite for long term storage of nuclear waste

Science.gov (United States)

Ajeesh, G.; Bhowmik, Shantanu; Sivakumar, Venugopal; Varshney, Lalit; Kumar, Virendra; Abraham, Mathew

2015-12-01

This investigation highlights the effect of radiation, chemical and thermal environments on mechanical and thermal properties of Polyetheretherketone (PEEK) composites, which could prove to be an alternative material for long term storage of nuclear wastes. The tests are conducted on specimens made from PEEK and PEEK reinforced with carbon short fiber. The specimens are subjected to radiation doses, equivalent to the cumulative dosage for 500 years followed by exposure under highly corrosive and thermal environments. Studies under optical microscopy reveal that the dispersion of carbon short fiber in the PEEK Composites is significantly uniform. Differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) indicates that there are no significant changes in thermal properties of PEEK composite when exposed to aggressive environments. It is further observed that there are no significant changes in mechanical properties of the composite after exposure to radiation and thermo-chemical environment.

Investigation on polyetheretherketone composite for long term storage of nuclear waste

International Nuclear Information System (INIS)

Ajeesh, G.; Bhowmik, Shantanu; Sivakumar, Venugopal; Varshney, Lalit; Kumar, Virendra; Abraham, Mathew

2015-01-01

This investigation highlights the effect of radiation, chemical and thermal environments on mechanical and thermal properties of Polyetheretherketone (PEEK) composites, which could prove to be an alternative material for long term storage of nuclear wastes. The tests are conducted on specimens made from PEEK and PEEK reinforced with carbon short fiber. The specimens are subjected to radiation doses, equivalent to the cumulative dosage for 500 years followed by exposure under highly corrosive and thermal environments. Studies under optical microscopy reveal that the dispersion of carbon short fiber in the PEEK Composites is significantly uniform. Differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) indicates that there are no significant changes in thermal properties of PEEK composite when exposed to aggressive environments. It is further observed that there are no significant changes in mechanical properties of the composite after exposure to radiation and thermo-chemical environment.

A long-term stable power supply µDMFC stack for wireless sensor node applications

International Nuclear Information System (INIS)

Wu, Zonglin; Wang, Xiaohong; Li, Xiaozhao; Xu, Manqi; Liu, Litian

2014-01-01

In this paper, a passive, air-breathing four-cell micro direct methanol fuel cell (µDMFC) stack featuring a fuel delivery structure for long-term and stable power supply is designed, fabricated and tested. The fuel is reserved in a T-shaped tank and diffuses through the porous diffusion layer to the catalyst at the anode. A peak power density of 25.7 mW cm −2 and a maximum power output of 113 mW are achieved with 3 M methanol at room temperature, and the stack can produce 60 mW of power, even though only 5% fuel remains in the reservoir. Combined with a low-input dc–dc convertor, the stack can realize a stable and optional constant voltage output from 1 V–6 V. The stack successfully powered a heavy metal sensor node for water environment monitoring 12 d continuously, with consumption of 10 mL 5 M methanol solution. As such, it is believed to be applicable for powering wireless sensor nodes. (paper)

Design and functionality of a segmented heat-storage prototype utilizing stable supercooling of sodium acetate trihydrate in a solar heating system

DEFF Research Database (Denmark)

Englmair, Gerald; Moser, Christoph; Furbo, Simon

2018-01-01

acetate trihydrate composites to conserve the latent heat of fusion for long-term heat storage. A control strategy directed heat from a solar collector array to either the PCM storage or a water buffer storage. Several PCM units had to be charged in parallel when the solar collector output peaked at 16 k......A solar heating system with 22.4m2 of solar collectors, a heat storage prototype consisting of four 200 kg phase-change material (PCM) storage units, and a 735 L water tank was designed to improve solar heat supply in single-family houses. The PCM storage utilized stable supercooling of sodium......W. A single unit was charged with 27.4 kWh of heat within four hours on a sunny day, and the PCM temperature increased from 20 °C to 80 °C. The sensible heat from a single PCM unit was transferred to the water tank starting with about 32 kW of thermal power after it had fully melted at 80 °C. A mechanical...

A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

International Nuclear Information System (INIS)

Sannibale, F.

2004-01-01

We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

A model describing stable coherent synchrotron radiation in storage rings

International Nuclear Information System (INIS)

Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wuestefeld, G.; Huebers, H.-W.; Warnock, R.

2004-01-01

We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

Formation and Maintenance of Robust Long-Term Information Storage in the Presence of Synaptic Turnover.

Directory of Open Access Journals (Sweden)

Michael Fauth

2015-12-01

Full Text Available A long-standing problem is how memories can be stored for very long times despite the volatility of the underlying neural substrate, most notably the high turnover of dendritic spines and synapses. To address this problem, here we are using a generic and simple probabilistic model for the creation and removal of synapses. We show that information can be stored for several months when utilizing the intrinsic dynamics of multi-synapse connections. In such systems, single synapses can still show high turnover, which enables fast learning of new information, but this will not perturb prior stored information (slow forgetting, which is represented by the compound state of the connections. The model matches the time course of recent experimental spine data during learning and memory in mice supporting the assumption of multi-synapse connections as the basis for long-term storage.

Long-term stable transmission of 3-keV Ne7+ ions guided through nanocapillaries in polymers

International Nuclear Information System (INIS)

Stolterfoht, N.; Herczku, P.; Juhász, Z.; Kovács, S.T.S.; Rácz, R.; Biri, S.; Sulik, B.

2016-01-01

We studied blocking effects on 3-keV Ne 7+ ion guiding through nanocapillaries in highly insulating polyethylene terephthalate (PET) manufactured at different laboratories. The experiments were motivated in view of previous measurement with PET capillaries prepared at the GSI Helmholtz-Zentrum for which significant blocking effects were observed, whereas in various previous studies with PET capillaries these effects could not be detected. As the blocking effect on the GSI capillaries strongly depends on their areal density, similar dependencies were studied with the FLNR capillaries. Long-term stable transmission was observed for all densities of the FLNR capillaries in contrast to the previous results. These observations are interpreted by differences in the capillary surface conductivities in accordance with charge patch formations within the capillaries. It is pointed out that the observed stable transmission is favorable for applications of ion guiding in capillaries.

Synaptic scaling enables dynamically distinct short- and long-term memory formation.

Directory of Open Access Journals (Sweden)

Christian Tetzlaff

2013-10-01

Full Text Available Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

Synaptic scaling enables dynamically distinct short- and long-term memory formation.

Science.gov (United States)

Tetzlaff, Christian; Kolodziejski, Christoph; Timme, Marc; Tsodyks, Misha; Wörgötter, Florentin

2013-10-01

Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

Sustainable Solutions for Nuclear used Fuels Interim Storage

International Nuclear Information System (INIS)

Arslan, Marc; Favet, Dominique; Issard, Herve; Le Jemtel, Amaury; Drevon, Caroline

2014-01-01

AREVA has a unique experience in providing sustainable solutions for used fuel management, fitted with the needs of different customers in the world and with regulation in different countries. These solutions entail both recycling and interim storage technologies. In a first part, we will describe the various types of solutions for Interim Storage of UNF that have been implemented around the world for interim storage at reactor or centralized Pad solution in canisters dry storage, vault type storages for dry storage, dry storage of transportation casks (dual purpose) pools for wet storage, The experience for all these different families of interim storages in which AREVA is involved is extensive and will be discussed with respect to the new challenges: increase of the duration of the interim storage (long term interim storage) increase of burn up of the fuels In a second part of the presentation, special recycling features will be presented. In that case, interim storage of the used fuels is ensured in pools. This provides in the long term good conditions for the behaviour of the fuel and its retrievability. With recycling, the final waste (Universal Canister of vitrified fission products and compacted hulls and end pieces): is stable and licensed in many countries for the final disposal (France, UK, Belgium, NL, Switzerland, Germany, Japan, upcoming: Spain, Australia, Italy). Presents neither safety criticality risks nor proliferation risks (AREVA conditioned HLW and LL-ILW are free of IAEA safeguard constraints thanks to AREVA process high recovery and purification yields). It can therefore be safely stored in interim storage for more than 100 years before final disposal. Some economic considerations will also be discussed. In particular, in the case of long term interim storage of used fuels, there are growing uncertainties regarding the future needs of repackaging and transportation, which can result in future cost overruns. Meanwhile, in the recycling policy

Early and long-term outcomes of coronary artery bypass grafting in patients with acute coronary syndrome versus stable angina pectoris.

Science.gov (United States)

Fukui, Toshihiro; Tabata, Minoru; Morita, Satoshi; Takanashi, Shuichiro

2013-06-01

The aim of the present study was to determine the early and long-term outcomes of coronary artery bypass grafting in patients with acute coronary syndrome and stable angina pectoris. From September 2004 to September 2011, 382 patients with acute coronary syndrome (unstable angina pectoris and non-ST-segment elevation myocardial infarction) and 851 patients with stable angina pectoris underwent first-time isolated coronary artery bypass grafting at our institute. The early and long-term outcomes were compared between the 2 groups. Patients with acute coronary syndrome were older, were more likely to be women, had a smaller body surface area, and were more likely to have left main coronary artery disease. In both groups, bilateral internal thoracic artery grafts were used in approximately 89% of the patients, and off-pump techniques in approximately 97% of the patients. The acute coronary syndrome group had a greater operative death rate (2.6% vs 0.1%) and a greater incidence of low output syndrome (3.1% vs 1.2%) and hemodialysis requirement (2.9% vs 1.1%). Multivariate regression analysis demonstrated that age, acute coronary syndrome, lower ejection fraction, and higher creatinine level before surgery were independent predictors of operative death. However, among the hospital survivors, no differences were seen in freedom from all death (85.4% ± 2.5% vs 87.7% ± 2.0%), cardiac death (97.4% ± 0.9% vs 96.5% ± 0.9%), or major adverse cardiac and cerebrovascular events (78.0% ± 2.9% vs 78.1% ± 2.3%) at 7 years between the patients with acute coronary syndrome and stable angina pectoris. Although acute coronary syndrome is an independent predictor of early mortality in patients undergoing coronary artery bypass grafting, the long-term outcomes after surgery were similar between patients with acute coronary syndrome and stable angina pectoris who survived the early postoperative period. Copyright © 2013 The American Association for Thoracic Surgery. Published by

Industrial Foundations as Long-Term Owners

DEFF Research Database (Denmark)

Thomsen, Steen; Poulsen, Thomas; Børsting, Christa Winther

Short-termism has become a serious concern for corporate governance, and this has inspired a search for institutional arrangements to promote long-term decision-making. In this paper, we call attention to long-term ownership by industrial foundations, which is common in Northern Europe but little...... known in the rest of the world. We use a unique Danish data set to document that industrial foundations are long-term owners that practice long-term governance. We show that foundation ownership is highly stable compared to other ownership structures. Foundation-owned companies replace managers less...... frequently. They have conservative capital structures with low financial leverage. They score higher on an index of long-termism in finance, investment, and employment. They survive longer. Overall, our paper supports the hypothesis that corporate time horizons are influenced by ownership structures...

Modeling long-term dynamics of electricity markets

International Nuclear Information System (INIS)

Olsina, Fernando; Garces, Francisco; Haubrich, H.-J.

2006-01-01

In the last decade, many countries have restructured their electricity industries by introducing competition in their power generation sectors. Although some restructuring has been regarded as successful, the short experience accumulated with liberalized power markets does not allow making any founded assertion about their long-term behavior. Long-term prices and long-term supply reliability are now center of interest. This concerns firms considering investments in generation capacity and regulatory authorities interested in assuring the long-term supply adequacy and the stability of power markets. In order to gain significant insight into the long-term behavior of liberalized power markets, in this paper, a simulation model based on system dynamics is proposed and the underlying mathematical formulations extensively discussed. Unlike classical market models based on the assumption that market outcomes replicate the results of a centrally made optimization, the approach presented here focuses on replicating the system structure of power markets and the logic of relationships among system components in order to derive its dynamical response. The simulations suggest that there might be serious problems to adjust early enough the generation capacity necessary to maintain stable reserve margins, and consequently, stable long-term price levels. Because of feedback loops embedded in the structure of power markets and the existence of some time lags, the long-term market development might exhibit a quite volatile behavior. By varying some exogenous inputs, a sensitivity analysis is carried out to assess the influence of these factors on the long-run market dynamics

Stable CSR in storage rings: A model

International Nuclear Information System (INIS)

Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Venturini, Marco; Abo-Bakr, Michael; Feikes, Jorge; Holldack, Karsten; Kuske, Peter; Wustefeld, Godehart; Hubers, Heinz-Willerm; Warnock, Robert

2005-01-01

A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user s shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

Stable CSR in Storage Rings: A Model

International Nuclear Information System (INIS)

Sannibale, F.

2005-01-01

A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user's shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

Overview of technical Issues Associated with the Long Term Storage of Light Water Reactor used Nuclear Fuel

International Nuclear Information System (INIS)

Sorenson, Ken B.

2014-01-01

The nuclear power technical community is developing the technical basis for demonstrating the safety of storing used nuclear fuel for extended periods of time. The combination of reactor operations that off-load spent fuel to interim storage, coupled with delays in repository construction, has resulted in the expectation that storage periods may be for longer periods of time than originally intended. As more fuel continues to be off-loaded from operating reactors, the need for expanded interim storage also increases. As repository programs are delayed, interim storage requirements will likely exceed licensing term limits. To address these operational realities, there has been a concerted international effort to identify and prioritize the technical issues that need to be addressed in order to demonstrate the safety of storing used nuclear fuel for extended periods of time. Since this is an international effort, different storage systems, regulations, and policies need to be considered. This results in differences in technical issues, as well as differences in priorities. However, this effort also identifies important commonalities in some technical areas that need to be addressed. A broad-based international evaluation of these technical issues provides a better understanding of technical concerns as they relate to individual storage systems and specific national regulatory frameworks. While there are several international activities underway that are focused on long term storage, this paper will discuss the activities of the Electric Power Research Institute (EPRI)/Extended Storage Collaboration Program (ESCP) International Subcommittee. A status report detailing the identification and prioritization of the technical issues was presented at the PSAM11 Conference in June 2012 (1). Since that conference, a final report has been completed by the EPRI/ESCP International Subcommittee (2). This paper will provide important results of the final report as well as

A retrieval account of the long-term modality effect.

Science.gov (United States)

Glenberg, A M

1984-01-01

When to-be-remembered (TBR) word pairs are separated by distractor activity, recall of the last few audibly presented pairs is greater than recall of the last few visually presented pairs. The effect is found even after a considerably long distractor-filled retention interval. Five experiments disconfirm echoic storage, short-term storage and long-term storage accounts of these effects, as well as demonstrating that the effect is not an artifact of differential use of a recency-first output strategy. The data are generally consistent with the proposition that retrieval is disrupted by modality-specific similarity between to-be-remembered items and distractor information.

Examination of the rheological properties of stirred joghurt during the long-term storage by using dynamic oscillation method

Directory of Open Access Journals (Sweden)

Milica Vilušić

2003-07-01

Full Text Available In this work the rheological properties of stirred yoghurt during the longterm storage at 4 and 8°C were investigated. The optimal quantity of additives, in order to increase dry matter content (whole milk powder and whey protein-lactalbumin, was preliminary determined and the fermentation was performed. During 42 days, i.e., 1st, 7th, 14th, 21st, 28th, 35th and 42nd day of storage of stirred yoghurt, in refrigerator at 4 and 8°C, the changes of pH value, acidity and rheological properties by using of dynamic oscillation method were observed. Results of this work indicated that an addition of whole milk powder and whey protein have an influence on rheological properties of stirred yoghurt. The long-term storage of stirred yoghurt and the results of dynamic oscilations showed permanently higher G’storage (elasticity modulus, where elastic properties of viscoelastic products dominate, in comparison with the G” loss (viscosity modulus. Increased moduls of elasticy and viscosity, as function of time, permanently occurs at pH value 4.00 and lower, as an indication of alteration of long casein chains in the coagulum structure. Different temperatures of storage had no influence on changes of rheological properties of examinated types of stirred yoghur. The relation of above mentioned moduls of elasticy and viscosity kept the same increasing tendency.

Stability of Folate and Vitamin B 12 in Human Serum after Long-Term Storage: A Follow-Up after 13 Years

NARCIS (Netherlands)

Jansen, Eugène H. J. M.; Beekhof, Piet K.; Centre for Health Protection, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, Netherlands; Centre for Health Protection, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, Netherlands

2018-01-01

In epidemiological and nutrition research, it is very important to evaluate the stability of biomarkers as function of both storage time and temperature. In this study, the stability of folate and vitamin B 12 in human serum samples has been tested after long-term

Long-term effects of interference on short-term memory performance in the rat.

Science.gov (United States)

Missaire, Mégane; Fraize, Nicolas; Joseph, Mickaël Antoine; Hamieh, Al Mahdy; Parmentier, Régis; Marighetto, Aline; Salin, Paul Antoine; Malleret, Gaël

2017-01-01

A distinction has always been made between long-term and short-term memory (also now called working memory, WM). The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI) (HIWM task), or a task using a different pair in each trial expected to induce a low level of PI (LIWM task). Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a "within-session/short-term" PI effect. However, we also observed a different "between-session/long-term" PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be transferred and stored

Long-term effects of interference on short-term memory performance in the rat.

Directory of Open Access Journals (Sweden)

Mégane Missaire

Full Text Available A distinction has always been made between long-term and short-term memory (also now called working memory, WM. The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI (HIWM task, or a task using a different pair in each trial expected to induce a low level of PI (LIWM task. Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a "within-session/short-term" PI effect. However, we also observed a different "between-session/long-term" PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be

Sulfur poisoning of Ni/Gadolinium-doped ceria anodes: A long-term study outlining stable solid oxide fuel cell operation

Science.gov (United States)

Riegraf, Matthias; Zekri, Atef; Knipper, Martin; Costa, Rémi; Schiller, Günter; Friedrich, K. Andreas

2018-03-01

This work presents an analysis of the long-term behavior of nickel/gadolinium-doped ceria (CGO) anode-based solid oxide fuel cells (SOFC) under sulfur poisoning conditions. A parameter study of sulfur-induced irreversible long-term degradation of commercial, high-performance single cells was carried out at 900 °C for different H2/N2/H2S fuel gas atmospheres, current densities and Ni/CGO anodes. The poisoning periods of the cells varied from 200 to 1500 h. The possibility of stable long-term Ni/CGO anode operation under sulfur exposure is established and the critical operating regime is outlined. Depending on the operating conditions, two degradation phenomena can be observed. Small degradation of the ohmic resistance was witnessed for sulfur exposure times of approximately 1000 h. Moreover, degradation of the anode charge transfer resistance was observed to be triggered by the combination of a small anodic potential step and high sulfur coverage on Ni. The microstructural evolution of altered Ni/CGO anodes was examined post-mortem by means of SEM and FIB/SEM, and is correlated to the anode performance degradation under critical operating conditions, establishing Ni depletion, porosity increase and a tripe phase boundary density decrease in the anode functional layer. It is shown that short-term sulfur poisoning behavior can be used to assess long-term stability.

Evaluation of short-term and long-term stability of emulsions by centrifugation and NMR

International Nuclear Information System (INIS)

Tcholakova, S.; Denkov, N.; Ivanov, I.; Marinov, R.

2004-01-01

The effect of storage time on the coalescence stability and drop size distribution of egg yolk and whey protein concentrate stabilized emulsions is studied. The emulsion stability is evaluated by centrifugation, whereas the drop size distribution is measured by means of NMR and optical microscopy. The experimental results show that there is no general relation between the emulsion stability and the changes in the mean drop diameter upon shelf-storage of protein emulsions. On the other hand, it is shown that the higher short-term stability, measured by centrifugation immediately after emulsion preparation, corresponds to higher long-term stability (after their self-storage up to 60 days) for emulsions stabilized by the same type of emulsifier. In this way, we are able to obtain information for the long-term stability of emulsions in a relatively short period of time.(authors)

Deep wells integrated with microfluidic valves for stable docking and storage of cells.

Science.gov (United States)

Jang, Yun-Ho; Kwon, Cheong Hoon; Kim, Sang Bok; Selimović, Seila; Sim, Woo Young; Bae, Hojae; Khademhosseini, Ali

2011-02-01

In this paper, we describe a microfluidic mechanism that combines microfluidic valves and deep wells for cell localization and storage. Cells are first introduced into the device via externally controlled flow. Activating on-chip valves was used to interrupt the flow and to sediment the cells floating above the wells. Thus, valves could be used to localize the cells in the desired locations. We quantified the effect of valves in the cell storage process by comparing the total number of cells stored with and without valve activation. We hypothesized that in deep wells external flows generate low shear stress regions that enable stable, long-term docking of cells. To assess this hypothesis we conducted numerical calculations to understand the influence of well depth on the forces acting on cells. We verified those predictions experimentally by comparing the fraction of stored cells as a function of the well depth and input flow rate upon activation of the valves. As expected, upon reintroduction of the flow the cells in the deep wells were not moved whereas those in shallow wells were washed away. Taken together, our paper demonstrates that deep wells and valves can be combined to enable a broad range of cell studies. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A cost of long-term memory in Drosophila

OpenAIRE

Mery, Frederic; Kawecki, Tadeusz J.

2005-01-01

Two distinct forms of consolidated associative memory are known in Drosophila: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of anesthesia-resistant memory had no detectable effect on desiccation resistance. This finding may hel...

Long Term Storage with Surveillance of Canadian Prototype Nuclear Power Reactors

International Nuclear Information System (INIS)

Janzen, Rick

2008-01-01

Atomic Energy of Canada (AECL) was originally formed by the government of Canada in 1952 to perform research in radiation and nuclear areas. In the mid 1950's Canada decided to limit itself to peaceful uses of nuclear energy and AECL embarked on several research and development programs, one of them being the development of nuclear power plants. This led to the development of the CANDU TM design of heavy water power reactors, of which there are now 29 operating around the world. This presentation discusses the present state of the first two CANDU TM prototype reactors and a prototype boiling light water reactor and lessons learnt after being in a long-term storage with surveillance state for more than 20 years. AECL facilities undergo decommissioning by either a prompt or a deferred removal approach. Both approaches are initiated after an operating facility has been declared redundant and gone through final operational shutdown. For the deferred approach, initial decommissioning activities are performed to put the facility into a sustainable, safe, shutdown state to minimize the hazards and costs of the ensuing extended storage with surveillance (SWS) or Safestor phase. At the appropriate time, the facility is dismantled and removed, or put into a suitable condition for re-use. AECL has a number of facilities that were built during its history, and some of these are now redundant or will become redundant in the near future. The deferred removal approach is part of AECL's decommissioning strategy for several reasons: 1. Reduction in radiation doses to workers during the final dismantling, 2. No facilities are available yet in Canada for the management of quantity of wastes arising from decommissioning, 3. Financial constraints presented by the number of facilities that will undergo decommissioning, compared to the availability of funds to carry out the work. This has led to the development of a comprehensive decommissioning plan that includes all of AECL's redundant

Long-term stability of oxidative stress biomarkers in human serum.

NARCIS (Netherlands)

Jansen, Eugène H J M; Beekhof, Piet K; Viezeliene, Dale; Muzakova, Vladimira; Skalicky, Jiri

2017-01-01

The storage time and storage temperature might affect stability of oxidative stress biomarkers, therefore, they have to be analyzed after long-term storage of serum samples. The stability of three biomarkers reflecting oxidative stress: reactive oxygen metabolites (ROM) for hydroperoxides, total

Requirements for a long-term safety certification for chemotoxic substances stored in a final storage facility for high radioactive and heat-generating radioactive waste in rock salt formations

International Nuclear Information System (INIS)

Tholen, M.; Hippler, J.; Herzog, C.

2007-01-01

Within the scope of a project funded by the German Federal Ministry of Economics and Technology (Bundesministerium fuer Wirtschaft und Technologie, BMWi), a safety certification concept for a future permanent final storage for high radioactive and heat-generating radioactive waste (HAW disposal facility) in rock salt formations is being prepared. For a reference concept, compliance with safety requirements in regard to operational safety as well as radiological and non-radiological protection objectives related to long-term safety, including ground water protection, will be evaluated. This paper deals with the requirements for a long-term safety certification for the purpose of protecting ground water from chemotoxic substances. In particular, longterm safety certifications for the permanent disposal of radioactive waste in a HAW disposal facility in rock salt formations and for the dumping of hazardous waste in underground storage facilities in rock salt formations are first discussed, followed by an evaluation as to whether these methods can be applied to the long-term safety certification for chemotoxic substances. The authors find it advisable to apply the long-term safety certification for underground storage facilities to the long-term safety certification for chemotoxic substances stored in a HAW disposal facility in rock salt formations. In conclusion, a corresponding certification concept is introduced. (orig.)

Visual working memory buffers information retrieved from visual long-term memory.

Science.gov (United States)

Fukuda, Keisuke; Woodman, Geoffrey F

2017-05-16

Human memory is thought to consist of long-term storage and short-term storage mechanisms, the latter known as working memory. Although it has long been assumed that information retrieved from long-term memory is represented in working memory, we lack neural evidence for this and need neural measures that allow us to watch this retrieval into working memory unfold with high temporal resolution. Here, we show that human electrophysiology can be used to track information as it is brought back into working memory during retrieval from long-term memory. Specifically, we found that the retrieval of information from long-term memory was limited to just a few simple objects' worth of information at once, and elicited a pattern of neurophysiological activity similar to that observed when people encode new information into working memory. Our findings suggest that working memory is where information is buffered when being retrieved from long-term memory and reconcile current theories of memory retrieval with classic notions about the memory mechanisms involved.

Long-term storage and safe retrieval of human papillomavirus DNA using FTA elute cards.

Science.gov (United States)

Barth, Heidi; Morel, Adrien; Mougin, Christiane; Averous, Gerlinde; Legrain, Michèle; Fender, Muriel; Risch, Simone; Fafi-Kremer, Samira; Velten, Michel; Oudet, Pierre; Baldauf, Jean-Jacques; Stoll-Keller, Françoise

2016-03-01

Biobanking or collection and storage of specimens for future research purposes have become an essential tool in many fields of biomedical research and aims to provide a better understanding of disease mechanisms as well as the identification of disease-specific biomarkers that can navigate in complex diseases. In this study, we assessed the use of Flinders Technology Associates (FTA) cards as a long-term storage device for cervical specimens with suspected human papillomavirus (HPV) infections. HPV detection and genotyping results in liquid-based transport media were compared to HPV results from FTA cards. The overall agreement for the presence of any HPV infection between liquid-based medium and FTA cards stored for 1 year at ambient temperature was 100%. Reproducibility analysis of HPV detection and genotyping from FTA cards demonstrated that FTA cards are a reliable medium to store and preserve viral nucleic acids. Biobanking of cervical cells on FTA cards may provide a key resource for epidemiological and retrospective HPV studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-term stable transmission of 3-keV Ne{sup 7+} ions guided through nanocapillaries in polymers

Energy Technology Data Exchange (ETDEWEB)

Stolterfoht, N., E-mail: nico@stolterfoht.com [Helmholtz-Zentrum Berlin fnr Materialien und Energie, 14109 Berlin (Germany); Herczku, P.; Juhász, Z.; Kovács, S.T.S.; Rácz, R.; Biri, S.; Sulik, B. [Institute of Nuclear Research (ATOMKI), 4001 Debrecen (Hungary)

2016-11-15

We studied blocking effects on 3-keV Ne{sup 7+} ion guiding through nanocapillaries in highly insulating polyethylene terephthalate (PET) manufactured at different laboratories. The experiments were motivated in view of previous measurement with PET capillaries prepared at the GSI Helmholtz-Zentrum for which significant blocking effects were observed, whereas in various previous studies with PET capillaries these effects could not be detected. As the blocking effect on the GSI capillaries strongly depends on their areal density, similar dependencies were studied with the FLNR capillaries. Long-term stable transmission was observed for all densities of the FLNR capillaries in contrast to the previous results. These observations are interpreted by differences in the capillary surface conductivities in accordance with charge patch formations within the capillaries. It is pointed out that the observed stable transmission is favorable for applications of ion guiding in capillaries.

The long-term management of radioactive waste

International Nuclear Information System (INIS)

Faussat, A.

1988-01-01

After setting out the terms of reference of ANDRA (National agency for the management of radioactive waste), the author describes the current situation and the projects for the surface storage of waste of low and medium activity. He then discusses the work which has started on the construction of an underground laboratory for studying the storage of long life waste [fr

Intended long term performances of cementitious engineered barriers for future storage and disposal facilities for radioactive wastes in Romania

Directory of Open Access Journals (Sweden)

Sociu F.

2013-07-01

Full Text Available Considering the EU statements, Romania is engaged to endorse in the near future the IAEA relevant publications on geological repository (CNCANa, to update the Medium and Long Term National Strategy for Safe Management of Radioactive Waste and to approve the Road Map for Geological Repository Development. Currently, for example, spent fuel is wet stored for 6 years and after this period it is transported to dry storage in MACSTOR-200 (a concrete monolithic module where it is intended to remain at least 50 years. The present situation for radioactive waste management in Romania is reviewed in the present paper. Focus will be done on existent disposal facilities but, also, on future facilities planned for storage / disposal of radioactive wastes. Considering specific data for Romanian radioactive waste inventory, authors are reviewing the advance in the radioactive waste management in Romania considering its particularities. The team tries to highlight the expected limitations and unknown data related with cementitious engineered barriers that has to be faced in the near future incase of interim storage or for the upcoming long periods of disposal.

Non-intrusive long-term monitoring approaches

International Nuclear Information System (INIS)

Smathers, D.; Mangan, D.

1998-01-01

In order to promote internatinal confidence that the US and Russia are disarming per their commitments under Article 6 of the Non-Proliferation Treaty, an international verification regime may be applied to US and Russian excess fissile materials. Initially, it is envisioned that this verification regime would be applied at storage facilities; however, it should be anticipated that the verification regime would continue throughout any material disposition activities, should such activities be pursued. once the materials are accepted into the verification regime, it is assumed that long term monitoring will be used to maintain continuity of knowledge. The requirements for long term storage monitoring include unattended operation for extended periods of time, minimal intrusiveness on the host nation's safety and security activities, data collection incorporating data authentication, and monitoring redundancy to allow resolution of anomalies and to continue coverage in the event of equipment failures. Additional requirements include effective data review and analysis processes, operation during storage facility loading, procedure for removal of inventory items for safety-related surveillance, and low cost, reliable equipment. A monitoring system might include both continuous monitoring of storagecontainers and continuous area monitoring. These would be complemented with periodic on-site inspections. A fissile material storage facility is not a static operation. The initial studies have shown there are a number of valid reasons why a host nation may need them to remove material from the storage facility. A practical monitoring system must be able to accommodate necessary material movements

Effect of storage in short--and long-term commercial semen extenders on the motility, plasma membrane and chromatin integrity of boar spermatozoa.

Science.gov (United States)

De Ambrogi, Marco; Ballester, Juan; Saravia, Fernando; Caballero, Ignacio; Johannisson, Anders; Wallgren, Margareta; Andersson, Magnus; Rodriguez-Martinez, Heriberto

2006-10-01

For artificial insemination (AI) in pigs, preservation of liquid boar semen at 16-20 degrees C is still common practice as sperm cryopreservation remains suboptimal in this species. To meet the different needs of the swine industry, several extenders have been developed to preserve semen in liquid form for short--and long-term storage. In the present study, three different commercial extenders devised for short-term (BTS+) or long-term preservation (MR-A and X-Cell), were used to test whether storage of semen from four mature, fertile boars at 17 degrees C for 96 h would affect sperm characteristics relevant for fertility, such as motility, membrane integrity and chromatin stability. Computer-assisted sperm analysis, and stainings with the acylated membrane dye SYBR-14/propidium iodide, and acridine orange in connection with flow cytometry were used to evaluate these variables. Percentages of total motile spermatozoa decreased slightly, but significantly, after 72-96 h. While membrane integrity values varied during the period of study, no significant changes in either membrane integrity or chromatin stability were, however, registered. This suggests a customary 96-day storage at 17 degrees C in these extenders was too short an interval to cause losses of integrity in nuclear DNA in the boar population studied.

Multi-period MINLP model for optimising operation and structural changes to CHP plants in district heating networks with long-term thermal storage

International Nuclear Information System (INIS)

Tveit, Tor-Martin; Savola, Tuula; Gebremedhin, Alemayehu; Fogelholm, Carl-Johan

2009-01-01

By using thermal storages it is possible to decouple the generation of power and heat, and it can also lead to an reduction in investments, as the storage can be used to cover the peak load periods. This work presents a MINLP model that can be used for analysing new investments and the long-term operation of CHP plants in a district heating network with long-term thermal storage. The model presented in this work includes the non-linear off-design behaviour of the CHP plants as well as a generic mathematical model of the thermal storage, without the need to fix temperatures and pressure. The model is formulated in such a way that it is suitable for deterministic MINLP solvers. The model is non-convex, and subsequently global optimality cannot be guaranteed with local solvers. In order to reduce the chance of obtaining a poor local optimum compared to the global optimum, the model should be solved many times with the initial values varying randomly. It is possible to extract a lot of results from the model, for instance total annual profit, the optimal selection of process options, mass flow through the plant, and generated power from each plant. The formulation of the model makes it suitable for deterministic MINLP solvers

Monosynaptic connections made by the sensory neurons of the gill- and siphon-withdrawal reflex in Aplysia participate in the storage of long-term memory for sensitization

OpenAIRE

Frost, William N.; Castellucci, Vincent F.; Hawkins, Robert D.; Kandel, Eric R.

1985-01-01

We have found that in the gill- and siphon- withdrawal reflex of Aplysia, the memory for short-term sensitization grades smoothly into long-term memory with increased amounts of sensitization training. One cellular locus for the storage of the memory underlying short-term sensitization is the set of monosynaptic connections between the siphon sensory cells and the gill and siphon motor neurons. We have now also found that these same monosynaptic connections participate in the storage of the m...

Suitable areas for a long-term radioactive waste storage facility in Portugal

International Nuclear Information System (INIS)

Duarte, P.; Paiva, I.; Trindade, R.; Mateus, A.

2006-01-01

Radioactive wastes in Portugal result mainly from the application of radioactive materials in medicine, research, industry and from U-ores mining and milling activities. Sealed and unsealed sources (including liquid effluents and N.O.R.M.) classified as radioactive wastes have been collected, segregated, conditioned and stored in the Portuguese Radioactive Waste Interim Storage Facility (P.R.W.I.S.F.) since the sixties. The Radiological Protection and Nuclear Safety Department (D.P.R.S.N.) of the Nuclear and Technological Institute (I.T.N.) is responsible for the R.W.I.S.F. management, located nearby Lisbon (S.a.c.a.v. ). Despite recent improvements performed at R.W.I.S.F., the 300 m3 storage capacity will be soon used up if current average store-rate remains unaltered. Being aware of the tendency for radioactive waste production increase in Portugal and of the international rules and recommendations on disposal sites for this kind of wastes, it becomes clear that the P.R.W.I.S.F. must be updated. In this work, a first evaluation of suitable areas to host a long-term radioactive waste storage facility was carried out using a Geographic Information System (G.I.S.) base. Preference and exclusionary criteria were applied, keeping constant the map scale (1:1000000). After processing exclusionary criteria, remaining areas were scored by overlaying three preference criteria. A composite score was determined for each polygon (problem solution) by summing the three preference criteria scores. The highest scores resulted from the combination of these criteria correspond to 4% of the territory, spatially distributed in seven of the eighteen Portuguese mainland administrative districts. Work in progress will use this area as reference for site selection, criss-crossing appropriate criteria for scales ranging from 1:50000 to 1:25000. (authors)

Suitable areas for a long-term radioactive waste storage facility in Portugal

Energy Technology Data Exchange (ETDEWEB)

Duarte, P.; Paiva, I.; Trindade, R. [Instituto Tecnologico e Nuclear, Dept. de Proteccao Radiologica e Seguranca Nuclear, Sacavem (Portugal); Mateus, A. [Lisboa Univ., Dept. de Geologia and Creminer, Faculdade de Ciencias (Portugal)

2006-07-01

Radioactive wastes in Portugal result mainly from the application of radioactive materials in medicine, research, industry and from U-ores mining and milling activities. Sealed and unsealed sources (including liquid effluents and N.O.R.M.) classified as radioactive wastes have been collected, segregated, conditioned and stored in the Portuguese Radioactive Waste Interim Storage Facility (P.R.W.I.S.F.) since the sixties. The Radiological Protection and Nuclear Safety Department (D.P.R.S.N.) of the Nuclear and Technological Institute (I.T.N.) is responsible for the R.W.I.S.F. management, located nearby Lisbon (S.a.c.a.v. ). Despite recent improvements performed at R.W.I.S.F., the 300 m3 storage capacity will be soon used up if current average store-rate remains unaltered. Being aware of the tendency for radioactive waste production increase in Portugal and of the international rules and recommendations on disposal sites for this kind of wastes, it becomes clear that the P.R.W.I.S.F. must be updated. In this work, a first evaluation of suitable areas to host a long-term radioactive waste storage facility was carried out using a Geographic Information System (G.I.S.) base. Preference and exclusionary criteria were applied, keeping constant the map scale (1:1000000). After processing exclusionary criteria, remaining areas were scored by overlaying three preference criteria. A composite score was determined for each polygon (problem solution) by summing the three preference criteria scores. The highest scores resulted from the combination of these criteria correspond to 4% of the territory, spatially distributed in seven of the eighteen Portuguese mainland administrative districts. Work in progress will use this area as reference for site selection, criss-crossing appropriate criteria for scales ranging from 1:50000 to 1:25000. (authors)

Long-term stability of sodium caseinate-stabilized nanoemulsions.

Science.gov (United States)

Yerramilli, Manispuritha; Ghosh, Supratim

2017-01-01

Oil-in-water (5 wt%) nanoemulsions were prepared with different concentration (2.5-10 wt%) of sodium caseinate as a sole emulsifier and their long-term storage stability was investigated for 6 months. Previous studies associated with sodium caseinate looked only into nanoemulsion formation; hence the challenges with long-term stability were not addressed. All nanoemulsions displayed an average droplet size sodium caseinate-stabilized nanoemulsions.

An experimental study on the long-term stability of particle motion in hadron storage rings

International Nuclear Information System (INIS)

Fischer, W.

1995-12-01

Nonlinear magnetic fields in conjunction with tune modulation may lead to chaotic particle motion and thereby limit the dynamic aperture in hadron storage rings. This is on particular interest for high energy storage rings with superconducting magnets at injection energy where magnetic field errors and the beam size have their maximum values. At the CERN SPS a dynamic aperture experiment was performed with the aim of finding the relevant effects for the stability of single particle motion in hadron storage rings. Experimental results are compared to long-term particle tracking to test to which extent computer programs can predict the dynamic aperture under well known conditions. In addition, detailed investigations of the loss mechanisms were pursued to improve the phenomenological understanding of the intricate details of particle motion in phase space. In a complementary experiment at the HERA proton ring at injection energy the dynamic aperture was measured under normal operating conditions. The computer simulations for these measurements included a very detailed model of the nonlinear fields which were measured for each individual magnet. Simulation results for the LHC are shown that estimate the effect of tune ripple of different strength on the dynamic aperture for different sets of random nonlinear field errors. (orig.)

Long-term course of opioid addiction.

Science.gov (United States)

Hser, Yih-Ing; Evans, Elizabeth; Grella, Christine; Ling, Walter; Anglin, Douglas

2015-01-01

Opioid addiction is associated with excess mortality, morbidities, and other adverse conditions. Guided by a life-course framework, we review the literature on the long-term course of opioid addiction in terms of use trajectories, transitions, and turning points, as well as other factors that facilitate recovery from addiction. Most long-term follow-up studies are based on heroin addicts recruited from treatment settings (mostly methadone maintenance treatment), many of whom are referred by the criminal justice system. Cumulative evidence indicates that opioid addiction is a chronic disorder with frequent relapses. Longer treatment retention is associated with a greater likelihood of abstinence, whereas incarceration is negatively related to subsequent abstinence. Over the long term, the mortality rate of opioid addicts (overdose being the most common cause) is about 6 to 20 times greater than that of the general population; among those who remain alive, the prevalence of stable abstinence from opioid use is low (less than 30% after 10-30 years of observation), and many continue to use alcohol and other drugs after ceasing to use opioids. Histories of sexual or physical abuse and comorbid mental disorders are associated with the persistence of opioid use, whereas family and social support, as well as employment, facilitates recovery. Maintaining opioid abstinence for at least five years substantially increases the likelihood of future stable abstinence. Recent advances in pharmacological treatment options (buprenorphine and naltrexone) include depot formulations offering longer duration of medication; their impact on the long-term course of opioid addiction remains to be assessed.

Effects of glucose metabolism pathways on sperm motility and oxidative status during long-term liquid storage of goat semen.

Science.gov (United States)

Qiu, Jian-Hua; Li, You-Wei; Xie, Hong-Li; Li, Qing; Dong, Hai-Bo; Sun, Ming-Ju; Gao, Wei-Qiang; Tan, Jing-He

2016-08-01

Although great efforts were made to prolong the fertility of liquid-stored semen, limited improvements have been achieved in different species. Although it is expected that energy supply and the redox potential will play an essential role in sperm function, there are few reports on the impact of specific energy substrates on spermatozoa during liquid semen storage. Furthermore, although it is accepted that glucose metabolism through glycolysis provides energy, roles of pentose phosphate pathway (PPP) and tricarboxylic acid cycle remain to be unequivocally found in spermatozoa. We have studied the pathways by which spermatozoa metabolize glucose during long-term liquid storage of goat semen. The results indicated that among the substrates tested, glucose and pyruvate were better than lactate in maintaining goat sperm motility. Although both glycolysis and PPP were essential, PPP was more important than glycolysis to maintain sperm motility. Pentose phosphate pathway reduced oxidative stress and provided glycolysis with more intermediate products such as fructose-6-phosphate. Pyruvate entered goat spermatozoa through monocarboxylate transporters and was oxidized by the tricarboxylic acid cycle and electron transfer to sustain sperm motility. Long-term liquid semen storage can be used as a good model to study sperm glucose metabolism. The data are important for an optimal control of sperm survival during semen handling and preservation not only in the goat but also in other species. Copyright © 2016 Elsevier Inc. All rights reserved.

Free-anchored Nb2O5@graphene networks for ultrafast-stable lithium storage

Science.gov (United States)

Deng, Qinglin; Li, Mengjiao; Wang, Junyong; Jiang, Kai; Hu, Zhigao; Chu, Junhao

2018-05-01

Orthorhombic Nb2O5 (T-Nb2O5) has structural merit but poor electrical conductivity, limiting their applications in energy storage. Although graphene is frequently adopted to effectively improve its electrochemical properties, the ordinary modified methods cannot meet the growing demands for high-performance. Here, we demonstrate that different graphene modified routes play a vital role in affecting the electrochemical performances of T-Nb2O5. By only manual shaking within one minute, Nb2O5 nano-particles can be rapidly adsorbed onto graphene, then the free-anchored T-Nb2O5@graphene three-dimensional networks can be successfully prepared based on hydrogel method. As for the application in lithium-ion batteries, it performs outstanding rate character (129 mA h g-1 (25C rate), 110 mA h g-1 (50C rate) and 90 mA h g-1 (100C rate), correspond to 79%, 67% and 55% capacity of 0.5C rate, respectively) and excellent long-term cycling feature (˜70% capacity retention after 20000 cycles). Moreover, it still maintains similar ultrafast-stable lithium storage performances when Cu foil is substituted by Al foil as current collector. In addition, relevant kinetics mechanisms are also expounded. This work provides a versatile strategy for the preparation of graphene modified Nb2O5 or other types of nanoparticles.

Long-term management of the existing radioactive wastes and residues at the Niagara Falls Storage Site. Draft Environmental Impact Statement

International Nuclear Information System (INIS)

1984-08-01

The statement assesses and compares several alternatives for long-term management of the existing radioactive wastes and residues at the Niagara Falls Storage Site (NFSS), Lewiston, New York. The alternatives include: (1) no action (continued interim storage at NFSS within a diked and capped containment area), (2) long-term management at NFSS (improved containment, with or without modified form of the residues), (3) long-term management at other DOE sites (Hanford, Washington, or Oak Ridge, Tennessee), and (4) offsite management of the residues at Hanford or Oak Ridge and either leaving the wastes at NFSS or removing them for disposal in the ocean. In addition to alternatives analyzed in depth, several options are also considered, including: other modifications of residue form, modification of the basic conceptual designs, other containment design options, transportation routes, and transportation modes. The radiological health effects (primarily increased risk of cancer) associated with long-term management of the wastes and residues are expected to be smaller than the nonradiological risks of occupational and transportation-related injuries and deaths. During the action period, the risk is highest for workers if all wastes and residues are moved to Hanford. The risk is highest for the general public if the residues are moved to Hanford and the wastes are moved to the ocean. Dispersal of the slightly contaminated wastes in the ocean is not expected to result in any significant impacts on the ocean environment or pose any significant radiological risk to humans. For all alternatives, if controls ceased, there would be eventual dispersion of the radioactive materials to the environment. If it is assumed that all controls cease, predicted time for loss of covers over the buried materials ranges from several hundred years to more than two million years, depending on the use of the land surface

Long-term storage and safe retrieval of DNA from microorganisms for molecular analysis using FTA matrix cards.

Science.gov (United States)

Rajendram, D; Ayenza, R; Holder, F M; Moran, B; Long, T; Shah, H N

2006-12-01

We assessed the potential use of Whatman FTA paper as a device for archiving and long-term storage of bacterial cell suspensions of over 400 bacterial strains representing 61 genera, the molecular applications of immobilised DNA on FTA paper, and tested its microbial inactivation properties. The FTA paper extracted bacterial DNA is of sufficiently high quality to successfully carryout the molecular detection of several key genes including 16S rRNA, esp (Enterococcus surface protein), Bft (Bacteroides fragilis enterotoxin) and por (porin protein) by PCR and for DNA fingerprinting by random amplified polymorphic DNA-PCR (RAPD-PCR). To test the long-term stability of the FTA immobilised DNA, 100 of the 400 archived bacterial samples were randomly selected following 3 years of storage at ambient temperature and PCR amplification was used to monitor its success. All of the 100 samples were successfully amplified using the 16S rDNA gene as a target and confirmed by DNA sequencing. Furthermore, the DNA was eluted into solution from the FTA cards using a new alkaline elution procedure for evaluation by real-time PCR-based assays. The viability of cells retained on the FTA cards varied among broad groups of bacteria. For the more fragile gram-negative species, no viable cells were retained even at high cell densities of between 10(7) and 10(8) colony forming units (cfu) ml(-1), and for the most robust species such as spore-formers and acid-fast bacteria, complete inactivation was achieved at cell densities ranging between 10(1) and 10(4) cfu ml(-1). The inactivation of bacterial cells on FTA cards suggest that this is a safe medium for the storage and transport of bacterial nucleic acids.

Long-term properties of bituminized waste products

International Nuclear Information System (INIS)

Snellman, M.; Valkiainen, M.

1985-10-01

This study is a survey of the factors of importance for the long term behaviour of bituminized ion exchange resins. Phenomena occurring in bituminized waste products affected by the treatment, storage and disposal are identified. Test methods have been developed for characterizing product properties, which are important for the long-term behaviour. The long-term properties of bituminized ion-exchange resins are studied in a repository environment with access of water equilibrated with concrete. In these circumstances the most important properties are related to the interactions of bituminized waste with the surrounding barriers. The most important phenomena are water uptake due to rehydration of the resins and subsequent swelling of the product

Long-term properties of bituminized waste products

International Nuclear Information System (INIS)

Snellman, M.; Valkiainen, M.

1985-10-01

This study is a survey of the factors of importance for long term behaviour of bituminized ion exchange resins. Phenomena occurring in bituminized waste products affected by the treatment, storage and disposal are identified. Test methods have been developed for characterizing product properties, which are important for the long-term behaviour. The long-term properties of bituminized ion-exchange resins are studied in a repository environment with access of water equilibrated with concrete. In these circumstances the most important properties are ralated to the interactions of bituminized waste with the surrounding barriers. The most important phenomena are water uptake due to rehydration of the resins and subsequent swelling of the product. (author)

Long-term storage of 85Kr in amorphous zeolite 5A

International Nuclear Information System (INIS)

Penzhorn, R.D.; Noppel, H.E.; Dorea, A.; Guenther, K.; Leitzig, H.; Schuster, P.

1984-01-01

Ar, Kr and Xe can be immobilized in type A zeolites as well as in mordenite and chabazite, when the original crystal structure is hydrothermally vitrified in the presence of the densified gas. Zeolites containing a high percentage of earth alcali metals yield encapsulates that are thermally very stable. Gas fixation conditions are essentially independent of the form of aggregation of the matrix. Noble gas encapsulates were characterized by their specific surface area as well as by microprobe analysis, X-ray analysis and electron diffraction. The results indicate that Kr is immobilized in units smaller than the size of a zeolite crystal. The thermal conductivity of zeolites was determined experimentally in various fluid media. With the data obtained the heat transport through a final storage vessel cooled by natural air convection was calculated. The estimated temperature profiles correlate well with those obtained in experiments simulating a storage containment. To verify the process, active samples having specific activities up to 30 mCi/g have been prepared. Leaching results demonstrate the chemical stability of the Kr/5A encapsulates. A semi-pilot facility based on the one-way autoclave concept has been constructed and demonstrated in operation

Structural Changes in the Surface of Red Blood Cell Membranes during Long-Term Donor Blood Storage

Directory of Open Access Journals (Sweden)

V. V. Moroz

2012-01-01

Full Text Available Objective: to study changes in the surface of red blood cell membranes of donor blood at the macro- and ultrastructural level during its storage for 30 days and to evaluate the functional state of the red blood cell membrane during the whole storage period. Material and methods. The investigation was conducted on human whole blood and packed red blood cells placed in the specialized packs containing the preservative CPDA-1, by using calibrated electroporation and atomic force microscopy and measuring plasma pH. Conclusion. The long-term, up to 30-day, storage of whole blood and packed red blood cells at 4°C was attended by lower plasma pH and increased hemolysis rate constant during calibrated electroporation and by the development of oxidative processes. The hemolysis rate constant was also higher in the packed red blood cells than that in the whole blood. On days 5—6, the membrane structure showed defects that developed, as the blood was stored, and caused irreversible cell membrane damage by day 30. Key words: donor blood, red blood cell membranes, atomic force microscopy.

Stable, Long-Term, Spatial Memory in Young and Aged Rats Achieved with a One Day Morris Water Maze Training Protocol

Science.gov (United States)

Barrientos, Ruth M.; Kitt, Meagan M.; D'Angelo, Heather M.; Watkins, Linda R.; Rudy, Jerry W.; Maier, Steven F.

2016-01-01

Here, we present data demonstrating that a 1 d Morris water maze training protocol is effective at producing stable, long-term spatial memory in both young (3 mo old) and aged (24 mo old) F344xBN rats. Four trials in each of four sessions separated by a 2.5 h ISI produced robust selective search for the platform 1 and 4 d after training, in both…

Safety relevant aspects of the long-term intermediate storage of spent fuel elements and vitrified high-level radioactive wastes; Sicherheitstechnische Aspekte der langfristigen Zwischenlagerung von bestrahlten Brennelementen und verglastem HAW

Energy Technology Data Exchange (ETDEWEB)

Ellinger, A.; Geupel, S.; Gewehr, K.; Gmal, B.; Hannstein, V.; Hummelsheim, K.; Kilger, R.; Wagner, M. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany); Schmidt, G.; Spieth-Achtnich, A. [Oeko-Institut e.V. - Institut fuer angewandte Oekolgie (Germany)

2010-04-15

The currently in Germany pursued concept for management of spent fuel from nuclear power plants provides intermediate dry cask storage at the NPP sites until direct disposal in a deep geologic repository. In addition the earlier commissioned centralized dry storage facilities are being used for storage of high level radioactive waste returned from foreign reprocessing of German spent fuel performed so far. The dry interim storage facilities are licensed for 40 years of operation time. According to the German regulations a full scope periodic safety review is not required so far, neither practical experience on dry storage for this period of time is available. With regard to this background the report at hand is dealing with long term effects, which may affect safety of the interim storage during the 40 years period or beyond if appropriate, and with the question, whether additional analyses or monitoring measures may be required. Therefore relevant publications have been evaluated, calculations have been performed as well as a systematic screening with regard to loads and possible ageing effects has been applied to structures and components important for safety of the storage, in order to identify relevant long term effects, which may not have been considered sufficiently so far and to provide proposals for an improved ageing management. The report firstly provides an overview on the current state of technology describing shortly the national and international practice and experience. In the following chapters safety aspects of interim storage with regard to time dependent effects and variations are being analyzed and discussed. Among this not only technical aspects like the long term behavior of fuel elements, canisters and storage systems are addressed, but also operational long term aspects regarding personnel planning, know how conservation, documentation and quality management are taken into account. A separate chapter is dedicated to developing and describing

Long-term frozen storage of urine samples: a trouble to get PCR results in Schistosoma spp. DNA detection?

Science.gov (United States)

Fernández-Soto, Pedro; Velasco Tirado, Virginia; Carranza Rodríguez, Cristina; Pérez-Arellano, José Luis; Muro, Antonio

2013-01-01

Human schistosomiasis remains a serious worldwide public health problem. At present, a sensitive and specific assay for routine diagnosis of schistosome infection is not yet available. The potential for detecting schistosome-derived DNA by PCR-based methods in human clinical samples is currently being investigated as a diagnostic tool with potential application in routine schistosomiasis diagnosis. Collection of diagnostic samples such as stool or blood is usually difficult in some populations. However, urine is a biological sample that can be collected in a non-invasive method, easy to get from people of all ages and easy in management, but as a sample for PCR diagnosis is still not widely used. This could be due to the high variability in the reported efficiency of detection as a result of the high variation in urine samples' storage or conditions for handling and DNA preservation and extraction methods. We evaluate different commercial DNA extraction methods from a series of long-term frozen storage human urine samples from patients with parasitological confirmed schistosomiasis in order to assess the PCR effectiveness for Schistosoma spp. detection. Patients urine samples were frozen for 18 months up to 7 years until use. Results were compared with those obtained in PCR assays using fresh healthy human urine artificially contaminated with Schistosoma mansoni DNA and urine samples from mice experimentally infected with S. mansoni cercariae stored frozen for at least 12 months before use. PCR results in fresh human artificial urine samples using different DNA based extraction methods were much more effective than those obtained when long-term frozen human urine samples were used as the source of DNA template. Long-term frozen human urine samples are probably not a good source for DNA extraction for use as a template in PCR detection of Schistosoma spp., regardless of the DNA method of extraction used.

A look at new key performance criteria that could most affect the safety of long term storage of nuclear waste. A case study commissioned by CEA

International Nuclear Information System (INIS)

Marvy, A.; Lioure, A.; Heriard-Dubreuil, G.; Gadbois, S.; Schneider, T.; Schieber, C

2002-01-01

As part of the work scope set in the French law on high level long lived waste R and D passed in 1991, CEA is conducting research work to establish the scientific basis and assess the feasibility of long term storage as an option for the safe management of nuclear waste for periods as long as a few centuries. This goal is a significant departure from current industrial practice where storage facilities are usually built to last only a few decades. From a technical viewpoint such an extension in time seems feasible provided care and maintenance is exercised. Considering such long periods of time risk for Society of loosing oversight and control of such a facility is real which triggers the question of whether and how long term storage safety can be actually achieved. Therefore CEA commissioned a study in which MUTADIS Consultants and CEPN were both involved. The case study looks into several past and actual human enterprises conducted over significant periods of time - one dating back to the end of the 18th century - and identified off the nuclear field. Then-prevailing societal behaviour and organizational structures are screened out to show how they were and are still able to cope with similar oversight and control goals. As a result the study group obtained a set of performance criteria relating to issues like responsibility, securing funds, legal and legislative implications, economic sustainable development, all being areas which are not traditionally considered when technical studies are conducted. These criteria can be most useful from the design stage onward, first in an attempt to define the facility construction and operating guiding principles, and thereafter to substantiate the safety case for long term storage and get geared to the public dialogue on that undertaking should it become a reality. (author)

Short-term memory and long-term memory are still different.

Science.gov (United States)

Norris, Dennis

2017-09-01

A commonly expressed view is that short-term memory (STM) is nothing more than activated long-term memory. If true, this would overturn a central tenet of cognitive psychology-the idea that there are functionally and neurobiologically distinct short- and long-term stores. Here I present an updated case for a separation between short- and long-term stores, focusing on the computational demands placed on any STM system. STM must support memory for previously unencountered information, the storage of multiple tokens of the same type, and variable binding. None of these can be achieved simply by activating long-term memory. For example, even a simple sequence of digits such as "1, 3, 1" where there are 2 tokens of the digit "1" cannot be stored in the correct order simply by activating the representations of the digits "1" and "3" in LTM. I also review recent neuroimaging data that has been presented as evidence that STM is activated LTM and show that these data are exactly what one would expect to see based on a conventional 2-store view. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

High resolution numerical investigation on the effect of convective instability on long term CO2 storage in saline aquifers

International Nuclear Information System (INIS)

Lu, C; Lichtner, P C

2007-01-01

CO 2 sequestration (capture, separation, and long term storage) in various geologic media including depleted oil reservoirs, saline aquifers, and oceanic sediments is being considered as a possible solution to reduce green house gas emissions. Dissolution of supercritical CO 2 in formation brines is considered an important storage mechanism to prevent possible leakage. Accurate prediction of the plume dissolution rate and migration is essential. Analytical analysis and numerical experiments have demonstrated that convective instability (Rayleigh instability) has a crucial effect on the dissolution behavior and subsequent mineralization reactions. Global stability analysis indicates that a certain grid resolution is needed to capture the features of density-driven fingering phenomena. For 3-D field scale simulations, high resolution leads to large numbers of grid nodes, unfeasible for a single workstation. In this study, we investigate the effects of convective instability on geologic sequestration of CO 2 by taking advantage of parallel computing using the code PFLOTRAN, a massively parallel 3-D reservoir simulator for modeling subsurface multiphase, multicomponent reactive flow and transport based on continuum scale mass and energy conservation equations. The onset, development and long-term fate of a supercritical CO 2 plume will be resolved with high resolution numerical simulations to investigate the rate of plume dissolution caused by fingering phenomena

Automated and temperature-controlled micro-PIV measurements enabling long-term-stable microchannel acoustophoresis characterization.

Science.gov (United States)

Augustsson, Per; Barnkob, Rune; Wereley, Steven T; Bruus, Henrik; Laurell, Thomas

2011-12-21

We present a platform for micro particle image velocimetry (μPIV), capable of carrying out full-channel, temperature-controlled, long-term-stable, and automated μPIV-measurement of microchannel acoustophoresis with uncertainties below 5% and a spatial resolution in the order of 20 μm. A method to determine optimal μPIV-settings for obtaining high-quality results of the spatially inhomogeneous acoustophoretic velocity fields of large dynamical range is presented. In particular we study the dependence of the results on the μPIV interrogation window size and the number of repeated experiments. The μPIV-method was further verified by comparing it with our previously published particle tracking method. Using the μPIV platform we present a series of high-resolution measurements of the acoustophoretic velocity field as a function of the driving frequency, the driving voltage, and the resonator temperature. Finally, we establish a direct and consistent connection between the obtained acoustophoretic velocity fields, and continuous flow mode acoustophoresis, commonly used in applications.

Study of scenarios of long term management of low-activity long-life wastes

International Nuclear Information System (INIS)

2012-01-01

This document reports the study of scenarios for the management of different low-activity long-life radioactive wastes with reference to different French legal texts. After a presentation of the legal and technical context, the report presents different existing and projected storages (description and safety principles for the Cires and Aube centres and for the Cigeo project of deep geological storage centre). It addresses the various aspects of radiferous and graphite waste management on a long term: inventory, parcel, waste peculiarities, management scenarios, assessment of storage in SCR. It also addresses the case of other wastes such as bituminous coated wastes, those presenting a reinforced natural radioactivity or residues of uranium conversion processing. The last part presents the main orientations for the project

The long and short of dry vault storage [for spent fuel

International Nuclear Information System (INIS)

Bradley, N.; O'Tallamhain, C.; Grine, C.J.

1984-01-01

The case has been made for purchasing Magnox reactors outside the UK without any prior commitment to reprocessing, the fuel being stored for an interim period. Two alternative storage concepts using natural draught air-cooled vaults have been presented, one based upon experience of 'buffer' storage at gas-cooled reactors in Britain, and te second based on the long term 'interim' storage developed to a detailed design stage for British AGRs. Although storage scenarios for new Magnox stations are discussed, they may also be of interest in relation to other types of reactor. (U.K.)

Short- and long-term memory contributions to immediate serial recognition: evidence from serial position effects.

Science.gov (United States)

Purser, Harry; Jarrold, Christopher

2010-04-01

A long-standing body of research supports the existence of separable short- and long-term memory systems, relying on phonological and semantic codes, respectively. The aim of the current study was to measure the contribution of long-term knowledge to short-term memory performance by looking for evidence of phonologically and semantically coded storage within a short-term recognition task, among developmental samples. Each experimental trial presented 4-item lists. In Experiment 1 typically developing children aged 5 to 6 years old showed evidence of phonologically coded storage across all 4 serial positions, but evidence of semantically coded storage at Serial Positions 1 and 2. In a further experiment, a group of individuals with Down syndrome was investigated as a test case that might be expected to use semantic coding to support short-term storage, but these participants showed no evidence of semantically coded storage and evidenced phonologically coded storage only at Serial Position 4, suggesting that individuals with Down syndrome have a verbal short-term memory capacity of 1 item. Our results suggest that previous evidence of semantic effects on "short-term memory performance" does not reflect semantic coding in short-term memory itself, and provide an experimental method for researchers wishing to take a relatively pure measure of verbal short-term memory capacity, in cases where rehearsal is unlikely.

Long-term aversive taste memory requires insular and amygdala protein degradation.

Science.gov (United States)

Rodriguez-Ortiz, Carlos J; Balderas, Israela; Saucedo-Alquicira, Fernando; Cruz-Castañeda, Paulina; Bermudez-Rattoni, Federico

2011-03-01

Some reports have shown that the ubiquitin-proteasome system (UPS) is necessary to degrade repressor factors to produce new proteins essential to memory consolidation. Furthermore, recent evidence suggests that memory updating also relies on protein degradation through the UPS. To evaluate whether degradation of proteins is part of the cellular events needed for long-term storage of taste aversion, we injected lactacystin--an UPS inhibitor--into the amygdala and/or insular cortex 30 min before the first or second training trials. The results revealed that degradation of proteins in either the amygdala or insular cortex suffices for long-term stabilization of first-time encounter taste aversion. On the other hand, lactacystin applied in the insula, but not in the amygdala, before the second training prevented long-term storage of updated information. Our results support that degradation of proteins by means of the UPS is required every time taste aversion is to be stored in long-term memory. Copyright © 2010 Elsevier Inc. All rights reserved.

On the pathway towards disposal. The need for long-term interim storage of high-level nuclear waste; Auf dem Weg in die Endlagerung. Die Notwendigkeit der langfristigen Zwischenlagerung hoch radioaktiver Abfaelle

Energy Technology Data Exchange (ETDEWEB)

Budelmann, Harald; Koehnke, Dennis; Reichardt, Manuel [Technische Univ. Braunschweig (Germany). Inst. fuer Baustoffe, Massivbau und Brandschutz; Di Nucci, Maria Rosaria; Isidoro Losada, Ana Maria [Freie Univ. Berlin (Germany). Forschungszentrum fuer Umweltpolitik (FFU)

2017-09-01

The disposal of spent nuclear fuel is a still unsolved problem with social, ethical, economical, ecological and political dimensions. The stagnating decision process on the final repository concept in several countries has the consequence of the inclusion of long-term interim storage into the disposal concept. The contribution discusses several approaches. This opens the question whether the long-term interim storage is a matter of delaying tactic or a pragmatic solution on the way to a final repository.

Long-Term Stability of Oxide Nanowire Sensors via Heavily Doped Oxide Contact.

Science.gov (United States)

Zeng, Hao; Takahashi, Tsunaki; Kanai, Masaki; Zhang, Guozhu; He, Yong; Nagashima, Kazuki; Yanagida, Takeshi

2017-12-22

Long-term stability of a chemical sensor is an essential quality for long-term collection of data related to exhaled breath, environmental air, and other sources in the Internet of things (IoT) era. Although an oxide nanowire sensor has shown great potential as a chemical sensor, the long-term stability of sensitivity has not been realized yet due to electrical degradation under harsh sensing conditions. Here, we report a rational concept to accomplish long-term electrical stability of metal oxide nanowire sensors via introduction of a heavily doped metal oxide contact layer. Antimony-doped SnO 2 (ATO) contacts on SnO 2 nanowires show much more stable and lower electrical contact resistance than conventional Ti contacts for high temperature (200 °C) conditions, which are required to operate chemical sensors. The stable and low contact resistance of ATO was confirmed for at least 1960 h under 200 °C in open air. This heavily doped oxide contact enables us to realize the long-term stability of SnO 2 nanowire sensors while maintaining the sensitivity for both NO 2 gas and light (photo) detections. The applicability of our method is confirmed for sensors on a flexible polyethylene naphthalate (PEN) substrate. Since the proposed fundamental concept can be applied to various oxide nanostructures, it will give a foundation for designing long-term stable oxide nanomaterial-based IoT sensors.

Nicotine Modulates the Long-Lasting Storage of Fear Memory

Science.gov (United States)

Lima, Ramon H.; Radiske, Andressa; Kohler, Cristiano A.; Gonzalez, Maria Carolina; Bevilaqua, Lia R.; Rossato, Janine I.; Medina, Jorge H.; Cammarota, Martin

2013-01-01

Late post-training activation of the ventral tegmental area (VTA)-hippocampus dopaminergic loop controls the entry of information into long-term memory (LTM). Nicotinic acetylcholine receptors (nAChR) modulate VTA function, but their involvement in LTM storage is unknown. Using pharmacological and behavioral tools, we found that…

Thermochemical Heat Storage: from Reaction Storage Density to System Storage Density

NARCIS (Netherlands)

Jong, A.J. de; Vliet, L.D. van; Hoegaerts, C.L.G.; Roelands, C.P.M.; Cuypers, R.

2016-01-01

Long-term and compact storage of solar energy is crucial for the eventual transition to a 100% renewable energy economy. For this, thermochemical materials provide a promising solution. The compactness of a long-term storage system is determined by the thermochemical reaction, operating conditions,

Synthesis on the long term behavior of spent nuclear fuel. Vol.1,2; Synthese sur l'evolution a long terme des colis de combustibles irradies. Tome 1,2

Energy Technology Data Exchange (ETDEWEB)

Poinssot, Ch.; Toulhoat, P.; Grouiller, J.P.; Pavageau, J.; Piron, J.P.; Pelletier, M.; Dehaudt, Ph.; Cappelaere, Ch.; Limon, R.; Desgranges, L.; Jegou, Ch.; Corbel, C.; Maillard, S.; Faure, M.H.; Cicariello, J.C.; Masson, M. [CEA Saclay, DEN/DDIN/DPRGD, 91 - Gif sur Yvette (France)

2001-07-01

The aim of this report is to present the major objectives, the key scientific issues, and the preliminary results of the research conducted in France in the framework of the third line of the 1991 Law, on the topic of the long term behavior of spent nuclear fuel in view of long term storage or geological disposal. Indeed, CEA launched in 1998 the Research Program on the Long Term Behavior of Spent Nuclear Fuel (abbreviated and referred to as PRECCI in French; Poinssot, 1998) the aim of which is to study and assess the ability of spent nuclear fuel packages to keep their initially allocated functions in interim storage and geological disposal: total containment and recovery functions for duration up to hundreds of years (long term or short-term interim storage and/or first reversible stages of geological disposal) and partial confinement function (controlled fluxes of RN) for thousands of years in geological disposal. This program has to allow to obtain relevant and reliable data concerning the long term behavior of the spent fuel packages so that feasibility of interim storage and/or geological disposal can be assessed and demonstrated as well as optimized. Within this framework, this report presents for every possible scenario of evolution (closed system, in Presence of water in presence of gases) what are estimated to be the most relevant evolution mechanism. For the most relevant scientific issues hence defined, a complete scientific review of the best state of knowledge is subsequently here given thus allowing to draw a clear guideline of the major R and D issues for the next years. (authors)

Long-term urine biobanking: storage stability of clinical chemical parameters under moderate freezing conditions without use of preservatives.

Science.gov (United States)

Remer, Thomas; Montenegro-Bethancourt, Gabriela; Shi, Lijie

2014-12-01

To examine the long-term stability and validity of analyte concentrations of 21 clinical biochemistry parameters in 24-h urine samples stored for 12 or 15 yr at -22°C and preservative free. Healthy children's 24-h urine samples in which the respective analytes had been measured shortly after sample collection (baseline) were reanalyzed. Second measurement was performed after 12 yr (organic acids) and 15 yr (creatinine, urea, osmolality, iodine, nitrogen, anions, cations, acid-base parameters) with the same analytical methodology. Paired comparisons and correlations between the baseline and repeated measurements were done. Recovery rates were calculated. More than half of the analytes (creatinine, urea, iodine, nitrogen, sodium, potassium, magnesium, calcium, ammonium, bicarbonate, citric & uric acid) showed measurement values after >10 yr of storage not significantly different from baseline. 15 of the 21 parameters were highly correlated (r=0.99) between baseline and second measurement. Poorest correlation was r=0.77 for oxalate. Recovery ranged from 73% (oxalate) to 105% (phosphate). Our results suggest high long-term stability and measurement validity for numerous clinical chemistry parameters stored at -22°C without addition of any urine preservative. Prospective storage of urine aliquots at -22°C for periods even exceeding 10 yr, appears to be an acceptable and valid tool in epidemiological settings for later quantification of several urine analytes. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Synthesis of long live storage studies surface storage of MA-VL wastes

International Nuclear Information System (INIS)

Hollender, F.; Jourdain, F.; Piault, E.; Blanchet, Y.; Avakian, G.; Goger, F.; Caillaud, J.; Devictor, N.; Bary, B.; Moitier, C.; Breton, E.; Ranc, G.; Gaillard, J.P.; Lagrave, H.

2004-01-01

This document is realized in the framework of the axis 3 of the law of 1991 on the radioactive wastes management. It presents a long time surface storage installation of medium activity long life wastes. The long time of the installation would reach 300 years at the maximum. The feasibility is demonstrated and the design choices are presented and justified. The specific points of the long time storage installation, which are different from a classical industrial storage installation, are also discussed. (A.L.B.)

Long-term frozen storage of urine samples: a trouble to get PCR results in Schistosoma spp. DNA detection?

Directory of Open Access Journals (Sweden)

Pedro Fernández-Soto

Full Text Available BACKGROUND: Human schistosomiasis remains a serious worldwide public health problem. At present, a sensitive and specific assay for routine diagnosis of schistosome infection is not yet available. The potential for detecting schistosome-derived DNA by PCR-based methods in human clinical samples is currently being investigated as a diagnostic tool with potential application in routine schistosomiasis diagnosis. Collection of diagnostic samples such as stool or blood is usually difficult in some populations. However, urine is a biological sample that can be collected in a non-invasive method, easy to get from people of all ages and easy in management, but as a sample for PCR diagnosis is still not widely used. This could be due to the high variability in the reported efficiency of detection as a result of the high variation in urine samples' storage or conditions for handling and DNA preservation and extraction methods. METHODOLOGY/PRINCIPAL FINDINGS: We evaluate different commercial DNA extraction methods from a series of long-term frozen storage human urine samples from patients with parasitological confirmed schistosomiasis in order to assess the PCR effectiveness for Schistosoma spp. detection. Patients urine samples were frozen for 18 months up to 7 years until use. Results were compared with those obtained in PCR assays using fresh healthy human urine artificially contaminated with Schistosoma mansoni DNA and urine samples from mice experimentally infected with S. mansoni cercariae stored frozen for at least 12 months before use. PCR results in fresh human artificial urine samples using different DNA based extraction methods were much more effective than those obtained when long-term frozen human urine samples were used as the source of DNA template. CONCLUSIONS/SIGNIFICANCE: Long-term frozen human urine samples are probably not a good source for DNA extraction for use as a template in PCR detection of Schistosoma spp., regardless of the DNA

Diesel fuel long term storage and treatment- recommended tests and practices (U)

Energy Technology Data Exchange (ETDEWEB)

Gross, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2009-06-05

The Clean Air Act (1970) is the comprehensive federal law that regulates air emissions from stationary and mobile sources. Among other things, this law authorized the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards to protect public health and public welfare and to regulate emissions of hazardous air pollutants. In recent years, EPA regulations have forced oil refineries into producing a very low sulfur diesel fuel and incentives for adding up to 5% bio-diesel. These changes to the fuel oil formulation are beneficial to air quality and to energy conservation, but adversely impact heat content, long term storage stability, engine power, and injection system reliability. Diesel engines typically have a high incidence of injector failure resulting from poor diesel fuel quality. Since standby diesel engines do not run continuously it is necessary to implement periodic surveillance's to ensure the quality of diesel fuel is acceptable for reliable operation when a loss of power occurs. The information contained in this document is a compilation of best practices to be used as a guide for maintenance of a reliable diesel fuel system.

Graphitized Carbon: A Promising Stable Cathode Catalyst Support Material for Long Term PEMFC Applications.

Science.gov (United States)

Mohanta, Paritosh Kumar; Regnet, Fabian; Jörissen, Ludwig

2018-05-28

Stability of cathode catalyst support material is one of the big challenges of polymer electrolyte membrane fuel cells (PEMFC) for long term applications. Traditional carbon black (CB) supports are not stable enough to prevent oxidation to CO₂ under fuel cell operating conditions. The feasibility of a graphitized carbon (GC) as a cathode catalyst support for low temperature PEMFC is investigated herein. GC and CB supported Pt electrocatalysts were prepared via an already developed polyol process. The physical characterization of the prepared catalysts was performed using transmission electron microscope (TEM), X-ray Powder Diffraction (XRD) and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis, and their electrochemical characterizations were conducted via cyclic voltammetry(CV), rotating disk electrode (RDE) and potential cycling, and eventually, the catalysts were processed using membrane electrode assemblies (MEA) for single cell performance tests. Electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SEM) have been used as MEA diagonostic tools. GC showed superior stability over CB in acid electrolyte under potential conditions. Single cell MEA performance of the GC-supported catalyst is comparable with the CB-supported catalyst. A correlation of MEA performance of the supported catalysts of different Brunauer⁻Emmett⁻Teller (BET) surface areas with the ionomer content was also established. GC was identified as a promising candidate for catalyst support in terms of both of the stability and the performance of fuel cell.

An optimized cask technology for conditioning, transportation and long term interim storage of 'End of Life' nuclear waste

International Nuclear Information System (INIS)

Lefort-Mary, Florence; Clement, Gilles; Lamouroux, Christine; Dumont, Bruno

2016-01-01

When preparing for the decommissioning of a nuclear facility, during its 'end of life' management and while performing the actual dismantling operations, one has to consider a large diversity of nuclear waste in term of types, volumes and activities. Customers are frequently faced with the obligation to undertake multiple and costly waste management operations including handling, reconditioning or re-transferring from one package to another, for example when moving from on-site storage to transportation. To address this issue, a new - highly flexible - cask system named TN R MW is being developed. This cask has a total weight of 10 T and is compliant with the 2012 IAEA regulations. It is developed on a flexible concept basis, adaptable to the various nuclear needs, including: from IP2 to B(U) / B(U)F; on-site/ international transportation; long term interim storage. Licensing and manufacturing of number of items of this TN R MW family is underway. (authors)

Long-term relationships among pesticide applications, mobility, and soil erosion in a vineyard watershed.

Science.gov (United States)

Sabatier, Pierre; Poulenard, Jérôme; Fanget, Bernard; Reyss, Jean-Louis; Develle, Anne-Lise; Wilhelm, Bruno; Ployon, Estelle; Pignol, Cécile; Naffrechoux, Emmanuel; Dorioz, Jean-Marcel; Montuelle, Bernard; Arnaud, Fabien

2014-11-04

Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change.

Optimization of conditions for long-term prefreezing storage of brown bear sperm before cryopreservation.

Science.gov (United States)

López-Urueña, E; Alvarez, M; Gomes-Alves, S; Anel-López, L; Martínez-Rodríguez, C; Manrique, P; Borragan, S; Anel, L; de Paz, P

2015-10-15

Brown bear ejaculates are usually collected in field conditions and may need to be shipped to a laboratory for the application of reproductive biotechnologies before cryopreservation. The aim of this study was to extend the prefreezing step to 48 hours (1 hour vs. long-term storage [LS] to 24 and 48 hours) to enable the sample to be transported. The effects of storage temperature (experiment 1), glycerol concentration (experiment 2), and dilution rate (experiment 3) on sperm were evaluated. Electroejaculates from brown bears were stored under different experimental conditions and cryopreserved. The sperm motility and viability, apoptotic status, and acrosomal status of sperm were assessed before freezing (prefreezing), after thawing, and after 2-hour incubation at 37 °C (thermal stress test). In all experiments, one control sample was frozen using a standard protocol (control). In experiment 1, three temperatures during LS with 6% glycerol were tested: 5 °C (T5), 15 °C (T15), and room temperature (RT). The LS-T5 sample yielded the highest postthawing results for viability (42.4%), progressive motility (15.6%), and intact acrosome (83.1%) after 24 hours in comparison with the other temperatures (P bear electroejaculates are at 5 °C, at a concentration of 100 × 10(6) sperm/mL, and with 6% glycerol. Copyright © 2015 Elsevier Inc. All rights reserved.

ERDA's long-term waste management goals and programs

International Nuclear Information System (INIS)

Perge, A.F.; Trice, V.G. Jr.; Walton, R.D. Jr.

1976-01-01

This paper presents an overview of the ERDA's major program for the long-term waste management of radioactive waste and provides a perspective for symposium participants with regard to the interrelationship of specific components of the program that are discussed in detail in other ERDA-sponsored papers. Needs, goals, and plans are reviewed for ERDA's management of the commercially generated wastes which are expected to be delivered to ERDA in accordance with Federal regulations. At present, ERDA responsibilities include long-term management of commercial-level wastes. Possible future regulations may give ERDA responsibility for the long-term management of commercial low-level solid wastes contaminated with transuranic nuclides. Primary planning goals and programs for the development of terminal storage facilities and waste processing technology to produce acceptable waste forms for long-term management are reviewed for each of the waste types identified above. The status of development programs for the long-term management of airborne radionuclides, which may be required at some time in the future, is also reviewed. (author)

Long-Term Dry Storage of High Burn-Up Spent Pressurized Water Reactor (PWR) Fuel in TAD (Transportation, Aging, and Disposal) Containers

International Nuclear Information System (INIS)

Hwang, Yong Soo

2008-12-01

A TAD canister, in conjunction with specially-designed over-packs can accomplish the functions of transportation, aging, and disposal (TAD) in the management of spent nuclear fuel (SNF). Industrial dry cask systems currently available for SNF are licensed for storage-only or for dual-purpose (i.e., storage and transportation). By extending the function to include the indefinite storage and perhaps, eventual geologic disposal, the TAD canister would have to be designed to enhance, among others, corrosion resistance, thermal stability, and criticality-safety control. This investigative paper introduces the use of these advanced iron-based, corrosion-resistant materials for SNF transportation, aging, and disposal.The objective of this investigative project is to explore the interest that KAERI would research and develop its specific SAM coating materials for the TAD canisters to satisfy the requirements of corrosion-resistance, thermal stability, and criticality-controls for long-term dry storage of high burn-up spent PWR fuel

Impact of short-term severe accident management actions in a long-term perspective. Final Report

International Nuclear Information System (INIS)

2000-03-01

The present systems for severe accident management are focused on mitigating the consequences of special severe accident phenomena and to reach a safe plant state. However, in the development of strategies and procedures for severe accident management, it is also important to consider the long-term perspective of accident management and especially to secure the safe state of the plant. The main reason for this is that certain short-term actions have an impact on the long-term scenario. Both positive and negative effects from short-term actions on the accident management in the long-term perspective have been included in this paper. Short-term actions are accident management measures taken within about 24 hours after the initiating event. The purpose of short-term actions is to reach a stable status of the plant. The main goal in the long-term perspective is to maintain the reactor in a stable state and prevent uncontrolled releases of activity. The purpose of this short Technical Note, deliberately limited in scope, is to draw attention to potential long-term problems, important to utilities and regulatory authorities, arising from the way a severe accident would be managed during the first hours. Its objective is to encourage discussions on the safest - and maybe also most economical - way to manage a severe accident in the long term by not making the situation worse through inappropriate short-term actions, and on the identification of short-term actions likely to make long-term management easier and safer. The Note is intended as a contribution to the knowledge base put at the disposal of Member countries through international collaboration. The scope of the work has been limited to a literature search. Useful further activities have been identified. However, there is no proposal, at this stage, for more detailed work to be undertaken under the auspices of the CSNI. Plant-specific applications would need to be developed by utilities

Synthesis on the long term behavior of spent nuclear fuel. Vol.1,2

International Nuclear Information System (INIS)

Poinssot, Ch.; Toulhoat, P.; Grouiller, J.P.; Pavageau, J.; Piron, J.P.; Pelletier, M.; Dehaudt, Ph.; Cappelaere, Ch.; Limon, R.; Desgranges, L.; Jegou, Ch.; Corbel, C.; Maillard, S.; Faure, M.H.; Cicariello, J.C.; Masson, M.

2001-01-01

The aim of this report is to present the major objectives, the key scientific issues, and the preliminary results of the research conducted in France in the framework of the third line of the 1991 Law, on the topic of the long term behavior of spent nuclear fuel in view of long term storage or geological disposal. Indeed, CEA launched in 1998 the Research Program on the Long Term Behavior of Spent Nuclear Fuel (abbreviated and referred to as PRECCI in French; Poinssot, 1998) the aim of which is to study and assess the ability of spent nuclear fuel packages to keep their initially allocated functions in interim storage and geological disposal: total containment and recovery functions for duration up to hundreds of years (long term or short-term interim storage and/or first reversible stages of geological disposal) and partial confinement function (controlled fluxes of RN) for thousands of years in geological disposal. This program has to allow to obtain relevant and reliable data concerning the long term behavior of the spent fuel packages so that feasibility of interim storage and/or geological disposal can be assessed and demonstrated as well as optimized. Within this framework, this report presents for every possible scenario of evolution (closed system, in Presence of water in presence of gases) what are estimated to be the most relevant evolution mechanism. For the most relevant scientific issues hence defined, a complete scientific review of the best state of knowledge is subsequently here given thus allowing to draw a clear guideline of the major R and D issues for the next years. (authors)

Thermal and physicochemical properties important for the long term behavior of nuclear waste glasses

International Nuclear Information System (INIS)

Vernaz, E.; Matzke, H.J.

1992-01-01

High level nuclear waste from reprocessing of spent nuclear fuel has to be solidified in a stable matrix for safe long-time storage. Vitrification in borosilicate glasses is the technique accepted worldwide. A number of different glasses was developed in different national programs. The criteria and the reasons for selecting the final compositions are briefly described. Emphasis is placed on the French product R7T7 and on thermal and physicochemical properties though glasses developed in other national projects (e.g. the German product GP 98/12 etc.) are also treated. The basic physical and mechanical properties and the chemical durability of the glass in contact with water or other aqueous solutions are described. The basic mechanisms of aqueous corrosion are discussed and the evolving modelling of the leaching process is dealt with, as well as effects of container material, backfill, etc. The thermal behavior has also been studied and extensive data exist on diffusion of glass constituents (Na) and of interesting elements of the waste such as the alkalis Rb and Cs or the actinides U and Pu, as well as on crystallization processes in the glass during storage at elevated temperatures. Emphasis is placed on the radiation stability of the glasses, based on extensive studies using short-lived actinides (e.g. Cm-244) or ion-implantation to produce the damage expected during long storage at an accelerated rate. The radiation stability is shown to be very good, if realistic damage conditions are used. The knowledge accumulated in the past years is used to evaluate and predict the long-term evolution of the glass under storage conditions

Long-term stability of orbits in storage rings

International Nuclear Information System (INIS)

Warnock, R.L.; Ruth, R.D.

1990-06-01

We describe a numerical method to establish long-term bounds on nonlinear Hamiltonian motion. By bounding the change in a nearly constant action variable, uniformly in initial condition, one can predict stability for N turns by tracking many orbits for a member of turns of N 0 much less than N. In a first application to a model sextupole lattice in a region of strong nonlinearity, we predict stability of betatron motion in two degrees of freedom for 10 8 turns. 5 refs., 3 figs

Long-term evolution of radio-active waste storage in geological formations: analogy with the weathering of mineral deposits

International Nuclear Information System (INIS)

Cantinolle, P.; Griffault, L.; Jebrak, M.

1986-01-01

The aim of this study was to select examples of mineral deposits and their weathering environment, showing the long-term behaviour, in geological time, measuring (area, volume) some constituent elements of radio-active waste storage subject to the hazards of hydrogeochemical weathering. Initially, a feasibility study was made to collate data available within the BRGM (mining group and public service) and from literature dealing with weathering of deposits. It was thus discovered that the analogy between radio-active waste storage and mineral deposits could be approached in two different yet complementary ways: - one approach is to observe the behaviour of a mineral deposit in relation to the country rocks. For this a bibliographic metallogenic study was made. The other approach is to observe the behaviour of chemical elements during deposition of a mineral deposit whose genesis is similar to the spatial and thermal environment of a deposit of radio-active waste in a geological formation. For this two sites were selected corresponding to hydrothermal systems showing strong analogies to those expected in the neighbourhood of the storage sites. These two sites, Langenberg in the Vosges and La Telhaie in Brittany, were the subject of complementary analytical work [fr

A universal long-term flu vaccine may not prevent severe epidemics

Directory of Open Access Journals (Sweden)

Blower Sally

2010-04-01

Full Text Available Abstract Background Recently, the promise of a new universal long-term flu vaccine has become more tangible than ever before. Such a vaccine would protect against very many seasonal and pandemic flu strains for many years, making annual vaccination unnecessary. However, due to complacency behavior, it remains unclear whether the introduction of such vaccines would maintain high and stable levels of vaccination coverage year after year. Findings To predict the impact of universal long-term flu vaccines on influenza epidemics we developed a mathematical model that linked human cognition and memory with the transmission dynamics of influenza. Our modeling shows that universal vaccines that provide short-term protection are likely to result in small frequent epidemics, whereas universal vaccines that provide long-term protection are likely to result in severe infrequent epidemics. Conclusions Influenza vaccines that provide short-term protection maintain risk awareness regarding influenza in the population and result in stable vaccination coverage. Vaccines that provide long-term protection could lead to substantial drops in vaccination coverage and should therefore include an annual epidemic risk awareness programs in order to minimize the risk of severe epidemics.

Effects of tillage on contents of organic carbon, nitrogen, water-stable aggregates and light fraction for four different long-term trials

Science.gov (United States)

Andruschkewitsch, R.; Geisseler, D.; Koch, H.-J.; Ludwig, B.

2012-04-01

Despite increasing interest in tillage techniques as a factor affecting organic carbon (Corg) dynamics and stabilization mechanisms little is known about the underlying processes. Our objectives were (i) to quantify the impact of different tillage treatments on the amount and distribution of of labile Corg pools, on the water-stable macro-aggregate (>250 µm) contents and on organic carbon (Corg) storage and (ii) to quantify the ability of soils under different tillage treatments, light fraction (LF) inputs and clay contents in macro-aggregate formation. Therefore four long-term tillage trials on loess soil in Germany with regular conventional tillage (CT, to 30 cm), mulch tillage (MT, to 10 cm), and no-tillage (NT) treatments. Samples were taken in 0-5 cm, 5-25 cm and 25-40 cm depth after 18-25 years of different tillage treatments and investigated on free and occluded LF (fLF and oLF, respectively) and on macro-aggregate contents. Furthermore an incubation experiment for the quantifcation of macro-aggregate formation was conducted. Macro-aggregates in soils from CT and NT treatments (0-5 and 5-25 cm soil depth) were destroyed and different amounts of light fraction (LF) and clay were applied. The four long-term tillage trials, differing in texture and climatic conditions, revealed consistent results in Corg storage among each other. Based on the equivalent soil mass approach (CT: 0-40, MT: 0-38, NT: 0-36 cm) the Corg stocks in the sampled profile were significantly higher for the MT treatment than for the CT and NT treatments. Significantly lower Corg, fLF, oLF, and macro-aggregate contents for the soils under CT treatment in comparison with the soils under NT and MT treatments were restricted on the top 5 cm. The correlation of the macro-aggregate content against the fLF and oLF contents suggested that the macro-aggregate content is influenced to a lesser extent directly by the physical impact of the different tillage treatments but by the contents of available

Fukushima Daiichi. Post accident countermeasures and mid-and-long-term action plan

International Nuclear Information System (INIS)

Yamashita, Kazuhiko

2012-01-01

Since accident at Fukushima Daiichi nuclear power station, TEPCO had made strenuous efforts to maintain stable cooling of reactors and suppress discharge of radioactive materials under the cooperation of the government and others concerned. Various activities towards settlement of the accident had been done according to the roadmap proposed on April 17, 2011. This article described outlines of post accident countermeasures and current activities toward decommissioning based on mid-and-long-term action plan. Step 2 completion in roadmap towards settlement of the accident was confirmed on Dec. 16, 2011; (1) reactors: attainment of a condition equivalent to 'cold shutdown' with temperature of RPV bottom below 100degC, release of radioactive materials from PCV under control and public radiation exposure by additional release being significantly held down (evaluated as maximum 0.2 mSv/y at the site boundary), and mid-term safety of circulating water injection cooling system, (2) spent fuel pools: more stable cooling with circulating cooling system by installation of heat exchanger, (3) radioactive contaminated water: reduction of total amount with full-fledged processing facilities, desalination processing (reuse), storage and mitigation of contamination in the ocean, (4) commence construction of water shielding wall to prevent contamination of the ocean via the underground water, (5) installation of reactor building cover of unit 1 to restrain release of radioactive materials, and others. According to mid-to-long-term roadmap towards the decommissioning of Fukushima Nuclear Power Units 1-4, current activities were to (1) maintain stable reactor cooling and accumulated water processing and improve their credibility, (2) reduce the radiation impact due to additional emissions from the whole site and radioactive waste generated after the accident, (3) commence removal of fuel from the spent fuel pools (unit 4 within 2 years), (4) commence R and D and decontamination the

Co-ensiling as a new technique for long-term storage of agro-industrial waste with low sugar content prior to anaerobic digestion.

Science.gov (United States)

Hillion, Marie-Lou; Moscoviz, Roman; Trably, Eric; Leblanc, Yoann; Bernet, Nicolas; Torrijos, Michel; Escudié, Renaud

2018-01-01

Biodegradable wastes produced seasonally need an upstream storage, because of the requirement for a constant feeding of anaerobic digesters. In the present article, the potential of co-ensiling biodegradable agro-industrial waste (sugar beet leaves) and lignocellulosic agricultural residue (wheat straw) to obtain a mixture with low soluble sugar content was evaluated for long-term storage prior to anaerobic digestion. The aim is to store agro-industrial waste while pretreating lignocellulosic biomass. The dynamics of co-ensiling was evaluated in vacuum-packed bags at lab-scale during 180 days. Characterization of the reaction by-products and microbial communities showed a succession of metabolic pathways. Even though the low initial sugars content was not sufficient to lower the pH under 4.5 and avoid undesirable fermentations, the methane potential was not substantially impacted all along the experiment. No lignocellulosic damages were observed during the silage process. Overall, it was shown that co-ensiling was effective to store highly fermentable fresh waste evenly with low sugar content and offers new promising possibilities for constant long-term supply of industrial anaerobic digesters. Copyright © 2017 Elsevier Ltd. All rights reserved.

CRP on Demonstrating Performance of Spent Fuel and Related Storage Systems beyond the Long Term

International Nuclear Information System (INIS)

Bevilacqua, Arturo

2014-01-01

At the initial Coordinated Research Project (CRP) planning meeting held in August 2011, international experts in spent fuel performance confirmed the value of further coordination and development of international efforts to demonstrate the performance of spent fuel and related storage system components as durations extend. Furthermore, in recognition that the Extended Storage Collaboration Program (ESCP) managed by the Electric Power Research Institute (EPRI) in the USA, from now on ESCP, provided a broad context for the research and development work to be performed in the frame of this CRP, it was agreed that its objectives should target specific ESCP needs in order to make a relevant contribution. Accordingly, the experts examined on-going gap analyses - gaps between anticipated technical needs and existing technical data - for identify the specific research objectives. Additionally, during the planning meeting it was pointed out the need to coordinate and cooperate with the OECD/NEA counterparts involved in the organization of the International Workshop planned in autumn 2013 and with the on-going third phase of the CRP on Spent Fuel Performance Assessment and Research (SPAR-III). Given the importance to assess the performance of spent fuel and related important storage system components in order to confirm the viability of very long term storage for supporting the need to extend or renew licenses for storage facilities the CRP was approved by the IAEA in November 2011. While a full range of spent fuel types and storage conditions are deployed around the world, this CRP is focused on existing systems and, more specifically, water reactor fuel in dry storage with the overall research objective to support the technical basis for water reactor spent fuel management as dry storage durations extend. In March 2012 the group of international experts who participated at the initial CRP planning meeting in August 2011 evaluated and recommended for approval 9 research

R and D applied to the non-destructive characterization of waste packages for long term storage or deep disposal

Energy Technology Data Exchange (ETDEWEB)

Malvache, P.; Perot, B.; Ma, J.L.; Pettier, J.L. [CEA Cadarache, Dept. d' Etudes des Dechets, DED, 13 - Saint Paul lez Durance (France); Capdevila, J.M.; Huot, N. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares DDIN, 91 - Gif Sur Yvette (France); Moulin, V. [CEA Grenoble, Lab. d' Electronique, de Technologie de l' Information LETI, DSYS, 38 (France)

2001-07-01

To ensure the quality and traceability of waste package management in the long term, knowledge on these packages is necessary so as to confirm their compliance to storage or disposal specifications. Research is focused on the management of the knowledge on these packages (fabrication means, materials contained,...) and on the acquisition, through measurement, of their characteristics. Within this context, many studies are underway at the CEA in the field of measurements so as to obtain non- destructive tools to access the parameters which allow the waste packages to be characterized. The two main R and D investigations concern: the nuclear measurement methods for the detection and quantification of radionuclides and of chemical elements considered as important for storage or disposal safety ; the measurement methods for the physical characteristics of the packages by high energy photon imaging, thus allowing pictures of the contents of large, high density and sometimes irradiating packages to be known. During the last five years, the research at the CEA focused on these two areas and resulted in a significant evolution in the non-destructive characterization means for long lived waste packages. (author)

R and D applied to the non-destructive characterization of waste packages for long term storage or deep disposal

International Nuclear Information System (INIS)

Malvache, P.; Perot, B.; Ma, J.L.; Pettier, J.L.; Capdevila, J.M.; Huot, N.; Moulin, V.

2001-01-01

To ensure the quality and traceability of waste package management in the long term, knowledge on these packages is necessary so as to confirm their compliance to storage or disposal specifications. Research is focused on the management of the knowledge on these packages (fabrication means, materials contained,...) and on the acquisition, through measurement, of their characteristics. Within this context, many studies are underway at the CEA in the field of measurements so as to obtain non- destructive tools to access the parameters which allow the waste packages to be characterized. The two main R and D investigations concern: the nuclear measurement methods for the detection and quantification of radionuclides and of chemical elements considered as important for storage or disposal safety ; the measurement methods for the physical characteristics of the packages by high energy photon imaging, thus allowing pictures of the contents of large, high density and sometimes irradiating packages to be known. During the last five years, the research at the CEA focused on these two areas and resulted in a significant evolution in the non-destructive characterization means for long lived waste packages. (author)

Long-term changes in river system hydrology in Texas

Directory of Open Access Journals (Sweden)

Y. Zhang

2018-06-01

Full Text Available Climate change and human actives are recognized as a topical issue that change long-term water budget, flow-frequency, and storage-frequency characteristics of different river systems. Texas is characterized by extreme hydrologic variability both spatially and temporally. Meanwhile, population and economic growth and accompanying water resources development projects have greatly impacted river flows throughout Texas. The relative effects of climate change, water resources development, water use, and other factors on long-term changes in river flow, reservoir storage, evaporation, water use, and other components of the water budgets of different river basins of Texas have been simulated in this research using the monthly version of the Water Rights Analysis Package (WRAP modelling system with input databases sets from the Texas Commission on Environmental Quality (TCEQ and Texas Water Development Board (TWDB. The results show that long-term changes are minimal from analysis monthly precipitation depths. Evaporation rates vary greatly seasonally and for much of the state appear to have a gradually upward trend. River/reservoir system water budgets and river flow characteristics have changed significantly during the past 75 years in response to water resources development and use.

Stable Isotopes Reveal Long-Term Fidelity to Foraging Grounds in the Galapagos Sea Lion (Zalophus wollebaeki.

Directory of Open Access Journals (Sweden)

Massimiliano Drago

Full Text Available Most otariids have colony-specific foraging areas during the breeding season, when they behave as central place foragers. However, they may disperse over broad areas after the breeding season and individuals from different colonies may share foraging grounds at that time. Here, stable isotope ratios in the skull bone of adult Galapagos sea lions (Zalophus wollebaeki were used to assess the long-term fidelity of both sexes to foraging grounds across the different regions of the Galapagos archipelago. Results indicated that the stable isotope ratios (δ(13C and δ(15N of sea lion bone significantly differed among regions of the archipelago, without any significant difference between sexes and with a non significant interaction between sex and region. Moreover, standard ellipses, estimated by Bayesian inference and used as a measure of the isotopic resource use area at the population level, overlapped widely for the sea lions from the southern and central regions, whereas the overlap of the ellipses for sea lions from the central and western regions was small and non-existing for those from the western and southern regions. These results suggest that males and females from the same region within the archipelago use similar foraging grounds and have similar diets. Furthermore, they indicate that the exchange of adults between regions is limited, thus revealing a certain degree of foraging philopatry at a regional scale within the archipelago. The constraints imposed on males by an expanded reproductive season (~ 6 months, resulting from the weak reproductive synchrony among females, and those imposed on females by a very long lactation period (at least one year but up to three years, may explain the limited mobility of adult Galapagos sea lions of both sexes across the archipelago.

Impact of environmental factors on PADC radon detector sensitivity during long term storage

Science.gov (United States)

Wasikiewicz, J. M.

2018-01-01

A broad set of data on poly-allyl diglycol carbonate (PADC) exposure to various environmental conditions has been collected for a period of 1 year in order to study the aging effect on the sensitivity to radon detection. Aging is a phenomenon that occurs during long PADC storage resulting in a loss of sensitivity and/or creation of false tracks. Conditions under investigation were storages under pure nitrogen or air atmospheres, in water solutions of different pHs, in a range of temperatures, humidity and exposure to UV, gamma and neutron radiations. It was found that PADC strongly responds to some external conditions through physical changes in the polymer material; for example, etching of UV exposed detectors led to 10% loss of their thickness and the removal of the tracks layer. Performance of detectors was compared with a control that was the sensitivity of detectors from the same sheet at the time of primary calibration - within 1 month of each sheet being manufactured. Substantial difference in performance was found between storage under pure, dry nitrogen and in the presence of water. The former preserves PADC radon detection properties for the period of one year without noticeable change. The latter, on the other hand significantly reduces its performance even after 3 months' storage. It was also established that storage under low temperature is not a suitable means to preserve PADC sensitivity to radon detection due to significant loss in the detector sensitivity.

Long-term stability of salivary cortisol

DEFF Research Database (Denmark)

Garde, A H; Hansen, Åse Marie

2005-01-01

either stored in small vials or spiked to polyester Salivette tampons before analysis for cortisol using Spectria RIA kits. The effects of storage were evaluated by a linear regression model (mixed procedure) on a logarithmic scale. No effects on cortisol concentrations were found after storage of saliva......The measurement of salivary cortisol provides a simple, non-invasive, and stress-free measure frequently used in studies of the hypothalamic-pituitary-adrenal axis activity. In research projects, samples are often required to be stored for longer periods of time either because of the protocol...... of the project or because of lack of funding for analysis. The aim of the present study was to explore the effects of long-term storage of samples on the amounts of measurable cortisol. Ten pools of saliva were collected on polyester Salivette tampons from five subjects. After centrifugation the samples were...

Design analysis of various transportation package options for BN-350 SNF in terms of nuclear radiation safety in planning for long-terms dry storage

International Nuclear Information System (INIS)

Aisabekov, A.Z.; Mukenova, S.A.; Tur, E.S.; Tsyngaev, V.M.

2004-01-01

Full text: This effort is performed under the BN-350 reactor facility decommissioning project. One of the project tasks - spent nuclear fuel handling - includes the following: fuel packaging into sealed canisters, transportation of the canisters in multi-seat metallo-concrete containers and placement of the containers for a long-term dry storage. The goal of this effort is to computationally validate nuclear and radiation safety of the SNF containers placed for storage both under normal storage conditions and probable accident situations. The basic unit structure and design configurations are presented: assemblies, canisters, transportation containers. The major factors influencing nuclear and radiation safety are presented: fuel burn-up, enrichment, fabrication tolerance, types of fuel assemblies, configuration of assemblies in the canister and canisters in the container, background of assemblies placed in the reactor and cooling pool. Conditions under which the SNF containers will be stored are described and probable accident situations are listed. Proceeding from the conservatism principle, selection of the assemblies posing the greatest nuclear hazard is validated. A neutron effective multiplication factor is calculated for the SNF containers under the normal storage conditions and for the case of emergency. The effective multiplication factor is shown to be within a standard value of 0.95 in any situation. Based on the experimental data on assembly and canister dose rates, canisters posing the highest radiation threat are selected. Activities of sources and gamma-radiation spectral composition are calculated. Distribution of the dose rate outside the containers both under the normal storage conditions and accident situations are calculated. The results obtained are analyzed

Synthesis on the spent fuel long term evolution

Energy Technology Data Exchange (ETDEWEB)

Ferry, C.; Poinssot, Ch.; Lovera, P.; Poulesquen, A. [CEA Saclay, Dept. de Physico-Chimie (DEN/DPC), 91 - Gif sur Yvette (France); Broudic, V. [CEA Cadarache, Direction des Reacteurs Nucleaires (DRN), 13 - Saint Paul lez Durance (France); Cappelaere, Ch. [CEA Saclay, Dept. des Materiaux pour le Nucleaire(DMN), 91 - Gif-sur-Yvette (France); Desgranges, L. [CEA Cadarache, Direction des Reacteurs Nucleaires (DRN), 13 - Saint-Paul-lez-Durance (France); Garcia, Ph. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC), 13 - Saint Paul lez Durance (France); Jegou, Ch.; Roudil, D. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN), 30 - Marcoule (France); Lovera, P.; Poulesquen, A. [CEA Saclay, Dept. de Physico-Chimie (DPC), 91 - Gif sur Yvette (France); Marimbeau, P. [CEA Cadarache, Dir. de l' Energie Nucleaire (DEN), 13 - Saint-Paul-lez-Durance (France); Gras, J.M.; Bouffioux, P. [Electricite de France (EDF), 75 - Paris (France)

2005-07-01

The French research on spent fuel long term evolution has been performed by CEA (Commissariat a l'Energie Atomique) since 1999 in the PRECCI project with the support of EDF (Electricite de France). These studies focused on the spent fuel behaviour under various conditions encountered in dry storage or in deep geological disposal. Three main types of conditions were discerned: - The evolution in a closed system which corresponds to the normal scenario in storage and to the first confinement phase in disposal; - The evolution in air which corresponds to an incidental loss of confinement during storage or to a rupture of the canister before the site re-saturation in geological disposal; - The evolution in water which corresponds to the normal scenario after the breaching of the canister in repository conditions. This document produced in the frame of the PRECCI project is an overview of the state of knowledge in 2004 concerning the long-term behavior of spent fuel under these various conditions. The state of the art was derived from the results obtained under the PRECCI project as well as from a review of the literature and of data acquired under the European project on Spent Fuel Stability under Repository Conditions. The main results issued from the French research are underlined. (authors)

Synthesis on the spent fuel long term evolution

International Nuclear Information System (INIS)

Ferry, C.; Poinssot, Ch.; Lovera, P.; Poulesquen, A.; Broudic, V.; Cappelaere, Ch.; Desgranges, L.; Garcia, Ph.; Jegou, Ch.; Roudil, D.; Lovera, P.; Poulesquen, A.; Marimbeau, P.; Gras, J.M.; Bouffioux, P.

2005-01-01

The French research on spent fuel long term evolution has been performed by CEA (Commissariat a l'Energie Atomique) since 1999 in the PRECCI project with the support of EDF (Electricite de France). These studies focused on the spent fuel behaviour under various conditions encountered in dry storage or in deep geological disposal. Three main types of conditions were discerned: - The evolution in a closed system which corresponds to the normal scenario in storage and to the first confinement phase in disposal; - The evolution in air which corresponds to an incidental loss of confinement during storage or to a rupture of the canister before the site re-saturation in geological disposal; - The evolution in water which corresponds to the normal scenario after the breaching of the canister in repository conditions. This document produced in the frame of the PRECCI project is an overview of the state of knowledge in 2004 concerning the long-term behavior of spent fuel under these various conditions. The state of the art was derived from the results obtained under the PRECCI project as well as from a review of the literature and of data acquired under the European project on Spent Fuel Stability under Repository Conditions. The main results issued from the French research are underlined. (authors)

Data storage and retrieval for long-term dog studies

International Nuclear Information System (INIS)

Watson, C.R.; Trauger, G.M.; McIntyre, J.M.; Slavich, A.L.; Park, J.F.

1980-01-01

Over half of the 500,000 records collected on dogs in the last 20 years in our laboratory have been converted from sequential storage on magnetic tape to direct-access disk storage on a PDP 11/70 minicomputer. An interactive storage and retrieval system, based on a commercially available query language, has been developed to make these records more accessible. Data entry and retrieval are now performed by scientists and technicians rather than by keypunch operators and computer specialists. Further conversion awaits scheduled computer enhancement

Effects of Long-Term Storage Time and Original Sampling Month on Biobank Plasma Protein Concentrations

Directory of Open Access Journals (Sweden)

Stefan Enroth

2016-10-01

Full Text Available The quality of clinical biobank samples is crucial to their value for life sciences research. A number of factors related to the collection and storage of samples may affect the biomolecular composition. We have studied the effect of long-time freezer storage, chronological age at sampling, season and month of the year and on the abundance levels of 108 proteins in 380 plasma samples collected from 106 Swedish women. Storage time affected 18 proteins and explained 4.8–34.9% of the observed variance. Chronological age at sample collection after adjustment for storage-time affected 70 proteins and explained 1.1–33.5% of the variance. Seasonal variation had an effect on 15 proteins and month (number of sun hours affected 36 proteins and explained up to 4.5% of the variance after adjustment for storage-time and age. The results show that freezer storage time and collection date (month and season exerted similar effect sizes as age on the protein abundance levels. This implies that information on the sample handling history, in particular storage time, should be regarded as equally prominent covariates as age or gender and need to be included in epidemiological studies involving protein levels.

Storage options for Long Length Contaminated Equipment (LLCE) items

International Nuclear Information System (INIS)

Hodgson, R.D.

1994-11-01

A review of the Washington state requirements for the storage of long equipment items removed from tanks indicate that if the contaminated materials on the long equipment items are analyzed and determined to be DW, and not EHW, the containers can be stored on an uncovered, RCRA approved, storage pad. Long equipment items contaminated with reportable levels of EHW, or suspected of being contaminated with EHW, must be protected from the elements by means of a building or other protective covering that otherwise allows adequate inspection of the containers. Storage of the long equipment item containers on an uncovered storage pad is recommended and will reduce construction costs for new storage by an estimated 60 percent when compared to construction costs for enclosed storage

Long-term logistic analysis of FBR introduction strategy: avoiding both uranium and plutonium shortage

International Nuclear Information System (INIS)

Suzuki, T.

1995-01-01

Despite comfortable predictions on short to mid-term uranium resources, there is still a concern about long-term availability of competitive uranium resources. In order to achieve substantial uranium saving, early introduction of Fast Breeder Reactor (FBR) is desirable. But it is also known that rapid introduction of FBR could result in plutonium storage. Will there be enough plutonium on a global scale to sustain fast FBR growth? is there any other way to save uranium resource? This paper concludes that multi-option strategies to achieve flexible long-term strategy to avoid both uranium and plutonium storage are desirable. (authors)

Long-term preservation of Tetraselmis indica (Chlorodendrophyceae, Chlorophyta) for flow cytometric analysis: Influence of fixative and storage temperature.

Science.gov (United States)

Naik, Sangeeta Mahableshwar; Anil, Arga Chandrashekar

2017-08-01

Immediate enumeration of phytoplankton is seldom possible. Therefore, fixation and subsequent storage are required for delayed analysis. This study investigated the influence of glutaraldehyde (GA) concentrations (0.25%, 0.5%, and 1%) and storage temperatures (-80°C LN2 , -80°C, -20°C, and 5°C) on Tetraselmis indica for flow cytometric analysis. Cell recovery, granularity, and membrane permeability were independent of GA concentration whereas cell size and chlorophyll autofluorescence were concentration dependent. After an initial cell loss (16-19%), no cell loss was observed when samples were stored at 5°C. Cell recovery was not influenced by storage temperature until 4months but later samples preserved at -80°C LN2 , -80°C, and -20°C resulted in ~41% cell loss. Although maximum cell recovery with minimal effect on cell integrity was obtained at 5°C, autofluorescence was retained better at -80°C LN2 and -80°C. This suggests that in addition to fixative, the choice of storage temperature is equally important. Thus for long-term preservation, especially to retain autofluorescence, the use of lower concentration (0.25%) of GA when stored at a lower temperature (-80°C LN2 and -80°C) while a higher concentration (1%) of GA when stored at a higher temperature (5°C) is recommended. Copyright © 2017 Elsevier B.V. All rights reserved.

Introduction: Long term prediction

International Nuclear Information System (INIS)

Beranger, G.

2003-01-01

Making a decision upon the right choice of a material appropriate to a given application should be based on taking into account several parameters as follows: cost, standards, regulations, safety, recycling, chemical properties, supplying, transformation, forming, assembly, mechanical and physical properties as well as the behaviour in practical conditions. Data taken from a private communication (J.H.Davidson) are reproduced presenting the life time range of materials from a couple of minutes to half a million hours corresponding to applications from missile technology up to high-temperature nuclear reactors or steam turbines. In the case of deep storage of nuclear waste the time required is completely different from these values since we have to ensure the integrity of the storage system for several thousand years. The vitrified nuclear wastes should be stored in metallic canisters made of iron and carbon steels, stainless steels, copper and copper alloys, nickel alloys or titanium alloys. Some of these materials are passivating metals, i.e. they develop a thin protective film, 2 or 3 nm thick - the so-called passive films. These films prevent general corrosion of the metal in a large range of chemical condition of the environment. In some specific condition, localized corrosion such as the phenomenon of pitting, occurs. Consequently, it is absolutely necessary to determine these chemical condition and their stability in time to understand the behavior of a given material. In other words the corrosion system is constituted by the complex material/surface/medium. For high level nuclear wastes the main features for resolving problem are concerned with: geological disposal; deep storage in clay; waste metallic canister; backfill mixture (clay-gypsum) or concrete; long term behavior; data needed for modelling and for predicting; choice of appropriate solution among several metallic candidates. The analysis of the complex material/surface/medium is of great importance

Experimentation of a LiBr–H2O absorption process for long-term solar thermal storage: Prototype design and first results

International Nuclear Information System (INIS)

N'Tsoukpoe, K.E.; Le Pierrès, N.; Luo, L.

2013-01-01

The long-term thermal storage by absorption process studied in this paper is devoted to building heating. A demonstrative prototype that can store 8 kWh of heat and produce a heating power of 1 kW has been designed and built. It has been tested in static and dynamic operating conditions, which are compatible with domestic solar thermal and heating plants. The process operating principle, the prototype design and first experimental results are presented and discussed in this contribution. The charging process has been proved successful. The observed power during the charging phases is satisfactory, according to the process design for a real plant (2–5 kW). Absorption during discharging phase is also verified. Discharging tests show that absorption operates in conditions that could allow house heating as the absorber outlet solution temperature can reach 40 °C. However, some problems related to the absorber design have not allowed observing the heat recovery by the heat transfer fluid as expected. Some avenues are explored prior to a new and more appropriate design and eventually a new operating mode. Various aspects such as the use of a heat and mass transfer enhancement additive and stratification in the solution storage tank have also been addressed. - Highlights: ► A long-term thermal storage prototype is tested under practical conditions. ► For the prototype design, a separate reactor is used with integrated components. ► The observed powers during the charging phases are satisfactory (2–5 kW). ► Following crystallisation phases, discharging tests enabled the crystal dissolution. ► Absorber temperature that could allow house heating (up to 40°C) has been observed

Development of nuclear fuel cycle technologies - bases of long-term provision of fuel and environmental safety of nuclear power

International Nuclear Information System (INIS)

Solonin, M.I.; Polyakov, A.S.; Zakharkin, B.S.; Smelov, V.S.; Nenarokomov, E.A.; Mukhin, I.V.

2000-01-01

To-day nuclear power is one of the options, however, to-morrow it may become the main source of the energy, thus, providing for the stable economic development for the long time to come. The availability of the large-scale nuclear power in the foreseeable future is governed by not only the safe operation of nuclear power plants (NPP) but also by the environmentally safe management of spent nuclear fuel, radioactive waste conditioning and long-term storage. More emphasis is to be placed to the closing of the fuel cycle in view of substantial quantities of spent nuclear fuel arisings. The once-through fuel cycle that is cost effective at the moment cannot be considered to be environmentally safe even for the middle term since the substantial build-up of spent nuclear fuel containing thousands of tons Pu will require the resolution of the safe management problem in the nearest future and is absolutely unjustified in terms of moral ethics as a transfer of the responsibility to future generations. The minimization of radioactive waste arisings and its radioactivity is only feasible with the closed fuel cycle put into practice and some actinides and long-lived fission radionuclides burnt out. The key issues in providing the environmentally safe fuel cycle are efficient processes of producing fuel for NPP, radionuclide after-burning included, a long-term spent nuclear fuel storage and reprocessing as well as radioactive waste management. The paper deals with the problems inherent in producing fuel for NPP with a view for the closed fuel cycle. Also discussed are options of the fuel cycle, its effectiveness and environmental safety with improvements in technologies of spent nuclear fuel reprocessing and long-lived radionuclide partitioning. (authors)

Development of nuclear fuel cycle technologies - bases of long-term provision of fuel and environmental safety of nuclear power

Energy Technology Data Exchange (ETDEWEB)

Solonin, M I; Polyakov, A S; Zakharkin, B S; Smelov, V S; Nenarokomov, E A; Mukhin, I V [SSC, RF, A.A. Bochvar ALL-Russia Research Institute of Inorganic Materials, Moscow (Russian Federation)

2000-07-01

To-day nuclear power is one of the options, however, to-morrow it may become the main source of the energy, thus, providing for the stable economic development for the long time to come. The availability of the large-scale nuclear power in the foreseeable future is governed by not only the safe operation of nuclear power plants (NPP) but also by the environmentally safe management of spent nuclear fuel, radioactive waste conditioning and long-term storage. More emphasis is to be placed to the closing of the fuel cycle in view of substantial quantities of spent nuclear fuel arisings. The once-through fuel cycle that is cost effective at the moment cannot be considered to be environmentally safe even for the middle term since the substantial build-up of spent nuclear fuel containing thousands of tons Pu will require the resolution of the safe management problem in the nearest future and is absolutely unjustified in terms of moral ethics as a transfer of the responsibility to future generations. The minimization of radioactive waste arisings and its radioactivity is only feasible with the closed fuel cycle put into practice and some actinides and long-lived fission radionuclides burnt out. The key issues in providing the environmentally safe fuel cycle are efficient processes of producing fuel for NPP, radionuclide after-burning included, a long-term spent nuclear fuel storage and reprocessing as well as radioactive waste management. The paper deals with the problems inherent in producing fuel for NPP with a view for the closed fuel cycle. Also discussed are options of the fuel cycle, its effectiveness and environmental safety with improvements in technologies of spent nuclear fuel reprocessing and long-lived radionuclide partitioning. (authors)

Analysis of long-term impacts of TRU waste remaining at generator/storage sites for No Action Alternative 2

International Nuclear Information System (INIS)

Buck, J.W.; Bagaasen, L.M.; Bergeron, M.P.; Streile, G.P.

1997-09-01

This report is a supplement to the Waste Isolation Pilot Plant Disposal-Phase Final Supplemental Environmental Impact Statement (SEIS-II). Described herein are the underlying information, data, and assumptions used to estimate the long-term human-health impacts from exposure to radionuclides and hazardous chemicals in transuranic (TRU) waste remaining at major generator/storage sites after loss of institutional control under No Action Alternative 2. Under No Action Alternative 2, TRU wastes would not be emplaced at the Waste Isolation Pilot Plant (WIPP) but would remain at generator/storage sites in surface or near-surface storage. Waste generated at smaller sites would be consolidated at the major generator/storage sites. Current TRU waste management practices would continue, but newly generated waste would be treated to meet the WIPP waste acceptance criteria. For this alternative, institutional control was assumed to be lost 100 years after the end of the waste generation period, with exposure to radionuclides and hazardous chemicals in the TRU waste possible from direct intrusion and release to the surrounding environment. The potential human-health impacts from exposure to radionuclides and hazardous chemicals in TRU waste were analyzed for two different types of scenarios. Both analyses estimated site-specific, human-health impacts at seven major generator/storage sites: the Hanford Site (Hanford), Idaho National Engineering and Environmental Laboratory (INEEL), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), Rocky Flats Environmental Technology Site (RFETS), and Savannah River Site (SRS). The analysis focused on these seven sites because 99 % of the estimated TRU waste volume and inventory would remain there under the assumptions of No Action Alternative 2

Long-term energy and climate implications of carbon capture and storage deployment strategies in the US coal-fired electricity fleet.

Science.gov (United States)

Sathre, Roger; Masanet, Eric

2012-09-04

To understand the long-term energy and climate implications of different implementation strategies for carbon capture and storage (CCS) in the US coal-fired electricity fleet, we integrate three analytical elements: scenario projection of energy supply systems, temporally explicit life cycle modeling, and time-dependent calculation of radiative forcing. Assuming continued large-scale use of coal for electricity generation, we find that aggressive implementation of CCS could reduce cumulative greenhouse gas emissions (CO(2), CH(4), and N(2)O) from the US coal-fired power fleet through 2100 by 37-58%. Cumulative radiative forcing through 2100 would be reduced by only 24-46%, due to the front-loaded time profile of the emissions and the long atmospheric residence time of CO(2). The efficiency of energy conversion and carbon capture technologies strongly affects the amount of primary energy used but has little effect on greenhouse gas emissions or radiative forcing. Delaying implementation of CCS deployment significantly increases long-term radiative forcing. This study highlights the time-dynamic nature of potential climate benefits and energy costs of different CCS deployment pathways and identifies opportunities and constraints of successful CCS implementation.

Effects of Cortisol on Short and Long Term Diet and Morphology

DEFF Research Database (Denmark)

Peiman, Kathryn S.; Birnie-Gauvin, Kim; Larsen, Martin Hage

2017-01-01

Glucocorticoids such as cortisol are released during stressful events. However, many of the effects of cortisol on animals in the wild are still poorly documented. We evaluated the effects of artificially elevated cortisol on diet and morphology over the short term (2 weeks) and long term (4 months......) using a wild population of juvenile semi-anadromous brown trout (Salmo trutta) in Denmark. We caught, tagged and manipulated juvenile fish while in their natal freshwater streams in the fall. Manipulations consisted of an exogenous intracoelomic injection of cortisol suspended in vegetable shortening...... using geometric morphometrics. Cortisol affected carbon stable isotope signatures but had minimal effects on nitrogen isotopes and morphology. Irrespective of treatment, carbon and nitrogen stable isotope values increased over time. This study shows that cortisol can have both short and long term...

Synthesis long life storage studies surface storage of vitrified wastes

International Nuclear Information System (INIS)

Beziat, A.; Breton, E.; Ranc, G.; Gaillard, J.P.; Lagrave, H.; Hollender, F.; Jourdain, F.; Piault, E.; Garnier, J.; Lamare, V.; Duret, B.; Helie, M.; Ferry, C.; Mijuin, D.; Gagnier, E.

2004-01-01

This document is realized in the framework of the axis 3 of the law of 1991 on the radioactive wastes management. It justifies the choices concerning long time surface storage installation of vitrified wastes, called high activity wastes. The long time of the installation would reach 300 years at the maximum. These wastes represent 1 % at the maximum, of radioactive wastes in France but 95 % of the whole radioactivity. Three main objectives were followed: provide a permanent containment of radionuclides; give the possibility of wastes containers retrieval at all the time; minimize the maintenance and the control. The results allow to conclude that the long time surface storage of high activity wastes is feasible. (A.L.B.)

Geothermal long-term modelling of a solar coupled geothermal probe heat storage in Crailsheim; Geothermische Langzeitmodellierung eines solargekoppelten Erdsonden-Waermespeichers in Crailsheim

Energy Technology Data Exchange (ETDEWEB)

Homuth, Sebastian; Mikisek, Philipp; Goetz, Annette E.; Sass, Ingo [Technische Univ. Darmstadt (Germany). Fachgebiet Angewandte Geothermie

2011-10-24

The thermal variations of the subsurface in the vicinity of a seasonal solar coupled geothermal probe heat storage were modeled using FEFLOW {sup registered} over a period of thirty years. The geothermal probe heat storage consists of eighty boreholes in an area of 85 square meters. The geothermal probes have a depth of 55 m and are mainly located in limestones of the Upper Muschelkalk (Triassic). The geothermal probe heat storage is thermally loaded from April to September. The thermal discharge takes place from October to March. The thermal and hydraulic input data of the model are based on three 80 meter deep geothermal probes (GWM 1-3) in the vicinity of the storage. The cores were completely lithologically, facially and finely stratigraphically affiliated. Measurements of thermal conductivity, permeability, porosity and density of 76 representative samples from the geothermal probe GWM 3 and measurements of the main fracture directions in two reference digestions at Crailsheim enabled a most realistic modeling of the storage. The results of the long-term modeling can be used for a detailed forecasting of the thermal alterations in the subsurface.

Irradiation of potatoes for long-term storage

International Nuclear Information System (INIS)

Srapenjanz, R.

1976-01-01

In the USSR gamma irradiation of potatoes is used for extending the storage life. The properties of potatoes are not changed, and the irradiation procedure is lower in cost than chemical treatments for sprout inhibition. Finally, a brief outline is given of investigations on sprout inhibition of potatoes in other socialist countries

The effect of long-term storage on the physiochemical and bactericidal properties of electrochemically activated solutions.

Science.gov (United States)

Robinson, Gareth; Thorn, Robin; Reynolds, Darren

2012-12-24

Electrochemically activated solutions (ECAS) are generated by electrolysis of NaCl solutions, and demonstrate broad spectrum antimicrobial activity and high environmental compatibility. The biocidal efficacy of ECAS at the point of production is widely reported in the literature, as are its credentials as a "green biocide." Acidic ECAS are considered most effective as biocides at the point of production and ill suited for extended storage. Acidic ECAS samples were stored at 4 °C and 20 °C in glass and polystyrene containers for 398 days, and tested for free chlorine, pH, ORP and bactericidal activity throughout. ORP and free chlorine (mg/L) in stored ECAS declined over time, declining at the fastest rate when stored at 20 °C in polystyrene and at the slowest rate when stored at 4 °C in glass. Bactericidal efficacy was also affected by storage and ECAS failed to produce a 5 log(10) reduction on five occasions when stored at 20 °C. pH remained stable throughout the storage period. This study represents the longest storage evaluation of the physiochemical parameters and bactericidal efficacy of acidic ECAS within the published literature and reveals that acidic ECAS retain useful bactericidal activity for in excess of 12 months, widening potential applications.

The Effect of Long-Term Storage on the Physiochemical and Bactericidal Properties of Electrochemically Activated Solutions

Directory of Open Access Journals (Sweden)

Gareth Robinson

2012-12-01

Full Text Available Electrochemically activated solutions (ECAS are generated by electrolysis of NaCl solutions, and demonstrate broad spectrum antimicrobial activity and high environmental compatibility. The biocidal efficacy of ECAS at the point of production is widely reported in the literature, as are its credentials as a “green biocide.” Acidic ECAS are considered most effective as biocides at the point of production and ill suited for extended storage. Acidic ECAS samples were stored at 4 °C and 20 °C in glass and polystyrene containers for 398 days, and tested for free chlorine, pH, ORP and bactericidal activity throughout. ORP and free chlorine (mg/L in stored ECAS declined over time, declining at the fastest rate when stored at 20 °C in polystyrene and at the slowest rate when stored at 4 °C in glass. Bactericidal efficacy was also affected by storage and ECAS failed to produce a 5 log10 reduction on five occasions when stored at 20 °C. pH remained stable throughout the storage period. This study represents the longest storage evaluation of the physiochemical parameters and bactericidal efficacy of acidic ECAS within the published literature and reveals that acidic ECAS retain useful bactericidal activity for in excess of 12 months, widening potential applications.

Long-term preservation of anammox bacteria.

Science.gov (United States)

Rothrock, Michael J; Vanotti, Matias B; Szögi, Ariel A; Gonzalez, Maria Cruz Garcia; Fujii, Takao

2011-10-01

Deposit of useful microorganisms in culture collections requires long-term preservation and successful reactivation techniques. The goal of this study was to develop a simple preservation protocol for the long-term storage and reactivation of the anammox biomass. To achieve this, anammox biomass was frozen or lyophilized at two different freezing temperatures (-60°C and in liquid nitrogen (-200°C)) in skim milk media (with and without glycerol), and the reactivation of anammox activity was monitored after a 4-month storage period. Of the different preservation treatments tested, only anammox biomass preserved via freezing in liquid nitrogen followed by lyophilization in skim milk media without glycerol achieved stoichiometric ratios for the anammox reaction similar to the biomass in both the parent bioreactor and in the freshly harvested control treatment. A freezing temperature of -60°C alone, or in conjunction with lyophilization, resulted in the partial recovery of the anammox bacteria, with an equal mixture of anammox and nitrifying bacteria in the reactivated biomass. To our knowledge, this is the first report of the successful reactivation of anammox biomass preserved via sub-zero freezing and/or lyophilization. The simple preservation protocol developed from this study could be beneficial to accelerate the integration of anammox-based processes into current treatment systems through a highly efficient starting anammox biomass.

Non steady-state model for dry oxidation of nuclear wastes metallic containers in long term interim storage conditions

International Nuclear Information System (INIS)

Bertrand, Nathalie; Desgranges, Clara; Poquillon, Dominique; Monceau, Daniel

2006-01-01

For high-level nuclear waste containers in long-term interim storage, dry oxidation will be the first and the main degradation mode. The reason is that, for this kind of waste, the temperature on the surface of the containers will be high enough to avoid any condensation phenomena for several years. Even if the scale growth kinetics is expected to be very slow since the temperature will be moderate at the beginning of the storage (around 300 deg. C) and will keep on decreasing, the metal thickness lost by dry oxidation over such a long period must be evaluated with a good reliability. To achieve this goal, modelling of the oxide scale growth is necessary and this is the aim of the dry oxidation studies, performed in the frame of the COCON programme. All existing oxidation models are based on the two main oxidation theories developed by Wagner between the 1930's and 1970's on the one hand, and by Cabrera and Mott in the 1960 and next by Fromhold on the other hand. These used to be associated with high temperature behaviour for Wagner's theory and with low temperature for the second one. Indeed it is certainly more relevant to consider their range of application in terms of the oxide scale thickness rather than in terms of temperature. The question is posed about which theory should an appropriate model rely on. It can be expected that the oxide scale could have a thickness ranging from a few tens of nanometers up to several tens of micrometers depending on temperature and class of alloys chosen. At the present time, low-alloyed steels or carbon steels are considered candidate materials for high-level nuclear waste containers in long term interim storage. For this type of alloys, the scale formed during the dry oxidation stage will be 'rapidly' thick enough to neglect the Mott field. Hence, in a first step, some basic models based on a parabolic rate assumption, that is to say Wagner's model, have been derived from experimental data on iron and on low-alloy steel

Numerical modelling of the long term mechanical behaviour of a storage cell for high level nuclear wastes

International Nuclear Information System (INIS)

Bian, H.B.; Jia, Y.; Duveau, G.; Shao, J.F.; Poutrel, A.

2010-01-01

Document available in extended abstract form only. In France, a clay formation, called Callovo-Oxfordian clay, is considered as potential geological barrier for storage of radioactive wastes. An underground research laboratory is constructed in this clay layer in Bure (CMHM). The French Radioactive Waste Management Agency (Andra) plans to conduct a series of full scale experiments in the Bure Underground Research Laboratory in order to study the coupled Chemo- Thermo-Hydraulic-Mechanical processes due to the excavation, ventilation, subsequent backfilling/sealing, corrosion of metal components and heat release from the radioactive wasters. These phenomena will occur in the storage structures and the geologic barrier for a short/very long period of time. Especially for the High-Level Wastes, due to the important increase of temperature released by the waste packages, the behaviour of geological barrier is perhaps perturbed and the design of repository is also influenced in terms of admissible thermal loading. In this paper, a disposal cell for the radioactive High-Level Wastes (HLW) is studied in order to analyser the coupled phenomena evolving in the HLW storage. The carbon steel is adopted as the first choice material for the container of waste because of its relevant geochemical condition. In the underground radioactive wastes storage, due to the arrival of water from the geological formation, the metallic components will be corroded, by step, with a decrease of mechanical resistance and a generated supplementary volume. The space between the metallic container and the host rock will then be closed under the combination of metallic corrosion and the behaviour differs of Callovo-Oxfordian clay. As results, important stress will be created on the interface of Callovo-Oxfordian clay and wastes packages. In addition, local hydration of barrier modifies the water infiltration from the Callovo-Oxfordian clay and the stress distribution in the argillite. According to

Simulation of Mechanical Processes in Gas Storage Caverns for Short-Term Energy Storage

Science.gov (United States)

Böttcher, Norbert; Nagel, Thomas; Kolditz, Olaf

2015-04-01

In recent years, Germany's energy management has started to be transferred from fossil fuels to renewable and sustainable energy carriers. Renewable energy sources such as solar and wind power are subjected by fluctuations, thus the development and extension of energy storage capacities is a priority in German R&D programs. This work is a part of the ANGUS+ Project, funded by the federal ministry of education and research, which investigates the influence of subsurface energy storage on the underground. The utilization of subsurface salt caverns as a long-term storage reservoir for fossil fuels is a common method, since the construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to solution mining. Another advantage of evaporate as host material is the self-healing behaviour of salt rock, thus the cavity can be assumed to be impermeable. In the framework of short-term energy storage (hours to days), caverns can be used as gas storage reservoirs for natural or artificial fuel gases, such as hydrogen, methane, or compressed air, where the operation pressures inside the caverns will fluctuate more frequently. This work investigates the influence of changing operation pressures at high frequencies on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. The salt behaviour is described by well-known constitutive material models which are capable of predicting creep, self-healing, and dilatancy processes. Our simulations include the thermodynamic behaviour of gas storage process, temperature development and distribution on the cavern boundary, the deformation of the cavern geometry, and the prediction of the dilatancy zone. Based on the numerical results, optimal operation modes can be found for individual caverns, so the risk of host rock damage

Utilizing cloud storage architecture for long-pulse fusion experiment data storage

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ming; Liu, Qiang [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, Hubei (China); School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, Hubei (China); Zheng, Wei, E-mail: zhenghaku@gmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, Hubei (China); School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, Hubei (China); Wan, Kuanhong; Hu, Feiran; Yu, Kexun [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, Hubei (China); School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, Hubei (China)

2016-11-15

Scientific data storage plays a significant role in research facility. The explosion of data in recent years was always going to make data access, acquiring and management more difficult especially in fusion research field. For future long-pulse experiment like ITER, the extremely large data will be generated continuously for a long time, putting much pressure on both the write performance and the scalability. And traditional database has some defects such as inconvenience of management, hard to scale architecture. Hence a new data storage system is very essential. J-TEXTDB is a data storage and management system based on an application cluster and a storage cluster. J-TEXTDB is designed for big data storage and access, aiming at improving read–write speed, optimizing data system structure. The application cluster of J-TEXTDB is used to provide data manage functions and handles data read and write operations from the users. The storage cluster is used to provide the storage services. Both clusters are composed with general servers. By simply adding server to the cluster can improve the read–write performance, the storage space and redundancy, making whole data system highly scalable and available. In this paper, we propose a data system architecture and data model to manage data more efficient. Benchmarks of J-TEXTDB performance including read and write operations are given.

Utilizing cloud storage architecture for long-pulse fusion experiment data storage

International Nuclear Information System (INIS)

Zhang, Ming; Liu, Qiang; Zheng, Wei; Wan, Kuanhong; Hu, Feiran; Yu, Kexun

2016-01-01

Scientific data storage plays a significant role in research facility. The explosion of data in recent years was always going to make data access, acquiring and management more difficult especially in fusion research field. For future long-pulse experiment like ITER, the extremely large data will be generated continuously for a long time, putting much pressure on both the write performance and the scalability. And traditional database has some defects such as inconvenience of management, hard to scale architecture. Hence a new data storage system is very essential. J-TEXTDB is a data storage and management system based on an application cluster and a storage cluster. J-TEXTDB is designed for big data storage and access, aiming at improving read–write speed, optimizing data system structure. The application cluster of J-TEXTDB is used to provide data manage functions and handles data read and write operations from the users. The storage cluster is used to provide the storage services. Both clusters are composed with general servers. By simply adding server to the cluster can improve the read–write performance, the storage space and redundancy, making whole data system highly scalable and available. In this paper, we propose a data system architecture and data model to manage data more efficient. Benchmarks of J-TEXTDB performance including read and write operations are given.

Evaluation of Thermal Creep and Hydride Re-orientation Properties of High Burnup Spent Fuel Cladding under Long Term Dry storage

Energy Technology Data Exchange (ETDEWEB)

Kamimura, K [JNES (Japan)

2012-07-01

In Japan, spent fuels will be reprocessed as recyclable energy source at a reprocessing plant. The first commercial plant is under-constructing and will start operation in 2008. It is necessary that spent fuels should be stored in the independent interim storage facilities (ISF) until reprocessing. Utilities plan the operation of the first ISF in 2010. JNES has a mission to support the safety body by researching the data of technical standard and regulation. Investigating of spent fuel integrity during long term dry storage is one of them. The objectives are: 1) Evaluation of the effects of material design changes on creep properties of high burnup spent fuel cladding; 2) Evaluation of the effects of alloy elements and texture of irradiated Zircaloy on hydride re-orientation properties and the effects of radial hydrides on cladding mechanical properties; 3) Evaluation of the effects of temperature on irradiation hardening recovery.

Review of the seismic risk in the design of civil engineering of nuclear installations excepted the long term storage of radioactive wastes

International Nuclear Information System (INIS)

2006-01-01

This guide aims to define, for the nuclear installations excepted the long term storage of radioactive wastes, from site data, the design specifications of earthquake resistant civil engineering and the possible methods for: the determination of the seismic response of the buildings, taking into account the interactions with the materials and the evaluation of the associated strains to size the installation; the determination of seismic displacements to be considered to size the materials. (A.L.B.)

The effect of long-term storage on nanoleakage.

Science.gov (United States)

Li, H P; Burrow, M F; Tyas, M J

2001-01-01

To evaluate the durability of dentin bonding over time, the nanoleakage of four dentin bonding systems (Single Bond, Stae, Clearfil SE Bond and PermaQuik) over 24 hours, three months, six months and 12 months, was investigated. Flat occlusal dentin surfaces from extracted human molars were finished with wet 600-grit silicon carbide paper and bonded with one of the dentin bonding systems following manufacturers' instructions. The bonded surface was covered with < 1 mm thick layer of Silux Plus resin composite and light cured for 40 seconds. The specimens in each dentin-bonding group were randomly assigned to four sub-groups and kept in phosphate buffered saline solution (pH 7.4) containing 0.01% sodium azide at 37 degrees C for 24 hours, three, six or 12 months. The margins of all specimens were finished and polished with Sof-Lex disks after initial 24-hour storage. At the end of each storage time, the surrounding tooth surfaces except for 1 mm adjacent to the restoration were coated with nail varnish. The samples were immersed in a 50% w/v solution of silver nitrate for 24 hours, placed in photodeveloping solution and exposed to fluorescent light for eight hours. The samples were cut longitudinally and buccoligually, polished, mounted on stubs, carbon coated and observed in a Field Emission-SEM using backscattered electron mode. The results showed that systems using phosphoric acid as the etchant had a line of silver deposition at the base of the hybrid layer. Silver deposition increased in all systems over 12-months storage, with PermaQuik changing the least. Nanoleakage of the dentin bonding systems increased slightly during the 12-month storage period, indicating that they may be subject to hydrolytic attack over time.

Long-term program for research and development of group separation and disintegration techniques

International Nuclear Information System (INIS)

1988-01-01

In Japan, the basic guidelines state that high-level radioactive wastes released from reprocessing of spent fuel should be processed into stable solid material, followed by storage for cooling for 30-50 years and disposal in the ground at a depth of several hundreds of meters. The Long-Term Program for Research and Development of Group Separation and Disintegration Techniques is aimed at efficient disposal of high-level wastes, reutilization of useful substances contained, and improved safety. Important processes include separation of nuclides (group separation, individual nuclide separation) and conversion (disintegration) of long-lived nuclides into short-lived or non-radioactive one. These processes can reduce the volume of high-level wastes to be left for final disposal. Research and development projects have been under way to provide techniques to separate high-level waste substances into four groups (transuranic elements, strontium/cesium, technetium/platinum group elements, and others). These projects also cover recovery of useful metals and efficient utilization of separated substances. For disintegration, conceptual studies have been carried out for the application of fast neutron beams to conversion of long half-life transuranium elements into short half-life or non-radioactive elements. (N.K.)

Effects of pH during liquid storage of goat semen on sperm viability and fertilizing potential.

Science.gov (United States)

Liu, Chang-He; Dong, Hai-Bo; Ma, Dong-Li; Li, You-Wei; Han, Dong; Luo, Ming-Jiu; Chang, Zhong-Le; Tan, Jing-He

2016-01-01

A specific problem in goat semen preservation is the detrimental effect of seminal plasma on sperm viability in extenders containing yolk or milk. Thus, the use of chemically defined extenders will have obvious advantages. Although previous studies indicate that the initial pH of an extender is crucial to sustain high sperm motility, changes in extender pH during long-term semen storage have not been observed. Monitoring extender pH at different times of semen storage and modeling its variation according to nonlinear models is thus important for protocol optimization for long-term liquid semen preservation. The present results showed that during long-term liquid storage of goat semen, both sperm motility and semen pH decreased gradually, and a strong correlation was observed between the two. Whereas increasing the initial extender pH from 6.04 to 6.25 or storage with stabilized pH improved, storage with artificially lowered pH impaired sperm motility. Extender renewal improved sperm motility by maintaining a stable pH. Sperm coating with chicken (Gallus gallus) egg yolk improved motility by increasing tolerance to pH decline. A new extender (n-mZAP) with a higher buffering capacity was formulated, and n-mZAP maintained higher sperm motility, membrane integrity and acrosome intactness than the currently used mZAP extender did. Goat semen liquid-stored for 12 d in n-mZAP produced pregnancy and kidding rates similar to those obtained with freshly collected semen following artificial insemination. In conclusion, maintenance of a stable pH during liquid semen storage dramatically improved sperm viability and fertilizing potential. Copyright © 2015 Elsevier B.V. All rights reserved.

The stability of the international oil trade network from short-term and long-term perspectives

Science.gov (United States)

Sun, Qingru; Gao, Xiangyun; Zhong, Weiqiong; Liu, Nairong

2017-09-01

To examine the stability of the international oil trade network and explore the influence of countries and trade relationships on the trade stability, we construct weighted and unweighted international oil trade networks based on complex network theory using oil trading data between countries from 1996 to 2014. We analyze the stability of international oil trade network (IOTN) from short-term and long-term aspects. From the short-term perspective, we find that the trade volumes play an important role on the stability. Moreover, the weighted IOTN is stable; however, the unweighted networks can better reflect the actual evolution of IOTN. From the long-term perspective, we identify trade relationships that are maintained during the whole sample period to reveal the situation of the whole international oil trade. We provide a way to quantitatively measure the stability of complex network from short-term and long-term perspectives, which can be applied to measure and analyze trade stability of other goods or services.

Hierarchically Macroporous Graphitic Nanowebs Exhibiting Ultra-fast and Stable Charge Storage Performance

Science.gov (United States)

Yun, Young Soo

2018-02-01

The macro/microstructures of carbon-based electrode materials for supercapacitor applications play a key role in their electrochemical performance. In this study, hierarchically macroporous graphitic nanowebs (HM-GNWs) were prepared from bacterial cellulose by high-temperature heating at 2400 °C. The HM-GNWs were composed of well-developed graphitic nanobuilding blocks with a high aspect ratio, which was entangled as a nanoweb structure. The morphological and microstructural characteristics of the HM-GNWs resulted in remarkable charge storage performance. In particular, the HM-GNWs exhibited very fast charge storage behaviors at scan rates ranging from 5 to 100 V s-1, in which area capacitances ranging from 8.9 to 3.8 mF cm-2 were achieved. In addition, 97% capacitance retention was observed after long-term cycling for more than 1,000,000 cycles.

The long-term management of information and records on radioactive waste packages in the United Kingdom

International Nuclear Information System (INIS)

Upshall, I.R.; Wisbey, S.J.

2002-01-01

It is generally accepted that information associated with the creation, conditioning and packaging of radioactive waste must be maintained for a considerable period of time. During the retention period not only must the storage media be preserved, but the data must remain accessible and in a form that can be interpreted with minimum 'processing'. This will ensure, as far as practicable, that the information accurately represents the nature of the waste and its packaging, that the media employed is suitable for long-term storage and that the storage conditions provide a stable environment. Careful consideration must be given to the type and form of the retained information and the threats to its continued integrity. United Kingdom Nirex Limited (Nirex), in association with experts in records media and management, has undertaken a programme of work to consider the range of media currently available, the threats to media integrity and the implications of a general move towards 'electronic' records. The results of this study are being used to develop an information management system strategy, capable of retaining data for all future phases of radioactive waste management. (author)

Long-term storage of radioactive solid waste within disposal facilities

International Nuclear Information System (INIS)

Wakerley, M.W.; Edmunds, J.

1986-05-01

A study of the feasibility and implications of operating potential disposal facilities for low and intermediate level solid radioactive waste in a retrievable storage mode for extended periods of up to 200 years has been carried out. The arisings of conditioned UK radioactive waste up to the year 2030 have been examined. Assignments of these wastes to different types of underground disposal facilities have been made on the basis of their present activity and that which they will have in 200 years time. Five illustrative disposal concepts proposed both in the UK and overseas have been examined with a view to their suitability for adaption for storage/disposal duty. Two concepts have been judged unsuitable because either the waste form or the repository structure were considered unlikely to last the storage phase. Three of the concepts would be feasible from a construction and operational viewpoint. This suggests that with appropriate allowance for geological aspects and good repository and waste form design that storage/disposal within the same facility is achievable. The overall cost of the storage/disposal concepts is in general less than that for separate surface storage followed by land disposal, but more than that for direct disposal. (author)

The Behaviours of Cementitious Materials in Long Term Storage and Disposal of Radioactive Waste. Results of a Coordinated Research Project

International Nuclear Information System (INIS)

2013-09-01

Radioactive waste with widely varying characteristics is generated from the operation and maintenance of nuclear power plants, nuclear fuel cycle facilities, research laboratories and medical facilities. This waste must be treated and conditioned, as necessary, to provide waste forms acceptable for safe storage and disposal. Many countries use cementitious materials (concrete, mortar, etc.) as a containment matrix for immobilization, as well as for engineered structures of disposal facilities. Radionuclide release is dependent on the physicochemical properties of the waste forms and packages, and on environmental conditions. In the use of cement, the diffusion process and metallic corrosion can induce radionuclide release. The advantage of cementitious materials is the added stability and mechanical support during storage and disposal of waste. Long interim storage is becoming an important issue in countries where it is difficult to implement low level waste and intermediate level waste disposal facilities, and in countries where cement is used in the packaging of waste that is not suitable for shallow land disposal. This coordinated research project (CRP), involving 24 research organizations from 21 Member States, investigated the behaviour and performance of cementitious materials used in an overall waste conditioning system based on the use of cement - including waste packaging (containers), waste immobilization (waste form) and waste backfilling - during long term storage and disposal. It also considered the interactions and interdependencies of these individual elements (containers, waste, form, backfill) to understand the processes that may result in degradation of their physical and chemical properties. The main research outcomes of the CRP are summarized in this report under four topical sections: (i) conventional cementitious systems; (ii) novel cementitious materials and technologies; (iii) testing and waste acceptance criteria; and (iv) modelling long

The Behaviours of Cementitious Materials in Long Term Storage and Disposal of Radioactive Waste. Results of a Coordinated Research Project

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-09-15

Radioactive waste with widely varying characteristics is generated from the operation and maintenance of nuclear power plants, nuclear fuel cycle facilities, research laboratories and medical facilities. This waste must be treated and conditioned, as necessary, to provide waste forms acceptable for safe storage and disposal. Many countries use cementitious materials (concrete, mortar, etc.) as a containment matrix for immobilization, as well as for engineered structures of disposal facilities. Radionuclide release is dependent on the physicochemical properties of the waste forms and packages, and on environmental conditions. In the use of cement, the diffusion process and metallic corrosion can induce radionuclide release. The advantage of cementitious materials is the added stability and mechanical support during storage and disposal of waste. Long interim storage is becoming an important issue in countries where it is difficult to implement low level waste and intermediate level waste disposal facilities, and in countries where cement is used in the packaging of waste that is not suitable for shallow land disposal. This coordinated research project (CRP), involving 24 research organizations from 21 Member States, investigated the behaviour and performance of cementitious materials used in an overall waste conditioning system based on the use of cement - including waste packaging (containers), waste immobilization (waste form) and waste backfilling - during long term storage and disposal. It also considered the interactions and interdependencies of these individual elements (containers, waste, form, backfill) to understand the processes that may result in degradation of their physical and chemical properties. The main research outcomes of the CRP are summarized in this report under four topical sections: (i) conventional cementitious systems; (ii) novel cementitious materials and technologies; (iii) testing and waste acceptance criteria; and (iv) modelling long

Synaptic Transmission Optimization Predicts Expression Loci of Long-Term Plasticity.

Science.gov (United States)

Costa, Rui Ponte; Padamsey, Zahid; D'Amour, James A; Emptage, Nigel J; Froemke, Robert C; Vogels, Tim P

2017-09-27

Long-term modifications of neuronal connections are critical for reliable memory storage in the brain. However, their locus of expression-pre- or postsynaptic-is highly variable. Here we introduce a theoretical framework in which long-term plasticity performs an optimization of the postsynaptic response statistics toward a given mean with minimal variance. Consequently, the state of the synapse at the time of plasticity induction determines the ratio of pre- and postsynaptic modifications. Our theory explains the experimentally observed expression loci of the hippocampal and neocortical synaptic potentiation studies we examined. Moreover, the theory predicts presynaptic expression of long-term depression, consistent with experimental observations. At inhibitory synapses, the theory suggests a statistically efficient excitatory-inhibitory balance in which changes in inhibitory postsynaptic response statistics specifically target the mean excitation. Our results provide a unifying theory for understanding the expression mechanisms and functions of long-term synaptic transmission plasticity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Implications of long-term surface or near-surface storage of intermediate and low-level wastes in the UK

International Nuclear Information System (INIS)

Murray, N.; Vande Putte, D.; Ware, R.J.

1986-02-01

Various options for 200 year-long storage of all Low- and Intermediate-Level wastes generated to the year 2030 are considered. On-site storage and centralised storage have been examined and compared. The feasibility of storing some of the wastes in underground facilities that are convertible to repositories has been demonstrated, but it is shown that centralised, surface storage of wastes would be more economical. There appears to be little merit in storing Intermediate Level wastes in separate facilities that could be converted to repositories. Storage is shown to be more expensive than direct disposal, except if future costs are discounted by more than about 10%. With carefully designed stores and remote handling, the collective dose to operators could be limited to about 20-40 man Sv over the whole period of storage. (author)

Mechanisms of translation control underlying long-lasting synaptic plasticity and the consolidation of long-term memory.

Science.gov (United States)

Santini, Emanuela; Huynh, Thu N; Klann, Eric

2014-01-01

The complexity of memory formation and its persistence is a phenomenon that has been studied intensely for centuries. Memory exists in many forms and is stored in various brain regions. Generally speaking, memories are reorganized into broadly distributed cortical networks over time through systems level consolidation. At the cellular level, storage of information is believed to initially occur via altered synaptic strength by processes such as long-term potentiation. New protein synthesis is required for long-lasting synaptic plasticity as well as for the formation of long-term memory. The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of cap-dependent protein synthesis and is required for numerous forms of long-lasting synaptic plasticity and long-term memory. As such, the study of mTORC1 and protein factors that control translation initiation and elongation has enhanced our understanding of how the process of protein synthesis is regulated during memory formation. Herein we discuss the molecular mechanisms that regulate protein synthesis as well as pharmacological and genetic manipulations that demonstrate the requirement for proper translational control in long-lasting synaptic plasticity and long-term memory formation. © 2014 Elsevier Inc. All rights reserved.

Long term storage of virus templated fluorescent materials for sensing applications

Energy Technology Data Exchange (ETDEWEB)

Seetharam, Raviraja N; Guerra, Charles; Satir, Peter [Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461 (United States); Blum, Amy Szuchmacher; Soto, Carissa M; Ratna, Banahalli R [Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Whitley, Jessica L [Geo-Centers, Incorporated, Newton, MA 02459 (United States); Sapsford, Kim E [George Mason University, 10910 University Boulevard, Manassas, VA 20110 (United States); Chatterji, Anju; Lin Tianwei; Johnson, John E [Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (United States)], E-mail: amy.blum@nrl.navy.mil

2008-03-12

Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications.

Long term storage of virus templated fluorescent materials for sensing applications

International Nuclear Information System (INIS)

Seetharam, Raviraja N; Guerra, Charles; Satir, Peter; Blum, Amy Szuchmacher; Soto, Carissa M; Ratna, Banahalli R; Whitley, Jessica L; Sapsford, Kim E; Chatterji, Anju; Lin Tianwei; Johnson, John E

2008-01-01

Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications

Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis

Directory of Open Access Journals (Sweden)

Yiran li

2013-10-01

Full Text Available This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs, based on eutectic mixtures as phase change materials (PCMs for thermal energy storage and high-density polyethylene (HDPE-ethylene-vinyl acetate (EVA polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD–capric acid (CA, TD–lauric acid (LA, and TD–myristic acid (MA, which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC. The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD–CA PCM, 24.53 °C/24.92 °C (FS TD–LA PCM, and 33.15 °C/30.72 °C (FS TD–MA PCM, respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM and Fourier-transform infrared (FT-IR spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP. It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties.

Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis.

Science.gov (United States)

Huang, Jingyu; Lu, Shilei; Kong, Xiangfei; Liu, Shangbao; Li, Yiran

2013-10-22

This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs), based on eutectic mixtures as phase change materials (PCMs) for thermal energy storage and high-density polyethylene (HDPE)-ethylene-vinyl acetate (EVA) polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD)-capric acid (CA), TD-lauric acid (LA), and TD-myristic acid (MA), which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC). The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD-CA PCM), 24.53 °C/24.92 °C (FS TD-LA PCM), and 33.15 °C/30.72 °C (FS TD-MA PCM), respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP). It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties.

Measurement of spin motions in a storage ring outside the stable polarization direction

International Nuclear Information System (INIS)

Akchurin, N.; Badano, L.; Bravar, A.; Istituto Nazionale di Fisica Nucleare, Legnaro

1993-06-01

Polarized, stored beams are becoming a more and more important tool in nuclear and high energy physics. In order to measure the beam polarization in a storage ring the polarization vector of the stored beams has to aim, revolution for revolution, over a period of seconds to minutes, into the same, so-called ''stable'' direction. In this paper measurements at the Indiana University cooler ring (IUCF) are described in which for the first time in a storage ring oscillations of the polarization vector around this stable direction have been measured. The existence and the dynamics of such oscillations are, for instance, important for a new proposed technique for polarizing stored hadron beams

Identification and understanding the factors affecting the public and political acceptance of long term storage of spent fuel and high-level radioactive wastes

International Nuclear Information System (INIS)

Gorea, Valica

2006-01-01

, during the storage. There is a powerful scientific and technical consensus according to which a well placed final repository must be provided with some barriers, including the geological and engineered ones. The wide-spread and accepted concept of final repository for spent fuel and high level waste is the so-called geological disposal which means the solid radioactive waste storage in underground repositories in a stable geological structure (ordinary at some hundreds of meters deep) so ensuring the isolation of radionuclides from biosphere on long term. The types of radioactive waste (high level and long life waste) which will be placed in geological repository are established by the national strategy and politics for the safe management of the radioactive waste. The development and implementation process of a repository can be achieved in the next non compulsory steps: - Developing the national politics in the field of safe management of the radioactive waste - Developing the legislative and institutional framework - Developing the technical concept of geological repository - Initiation of underground and surface investigations for the characterization of the host rock - Selecting the suitable site for an underground repository - Design, licensing for construction (which takes into account the environmental impact, nuclear safety and so on), operation and shut down. The decision to construct a geological repository must be taken by the Government or by the producers of waste. The steps for the establishing the legal framework, regulation and licensing are prerogatives of the Government, all the others steps could be achieved by non governmental organizations. The achievement of a geological repository, from the technical concept to the operation may last even more than 50 years and its operation some hundreds years. The paper contains the following sections: 1. Introduction; 2. Public and political acceptance; 3. Factors which affect the public and political

Activated carbon derived from waste coffee grounds for stable methane storage

International Nuclear Information System (INIS)

Kemp, K Christian; Baek, Seung Bin; Lee, Wang-Geun; Kim, Kwang S; Meyyappan, M

2015-01-01

An activated carbon material derived from waste coffee grounds is shown to be an effective and stable medium for methane storage. The sample activated at 900 °C displays a surface area of 1040.3 m"2 g"−"1 and a micropore volume of 0.574 cm"3 g"−"1 and exhibits a stable CH_4 adsorption capacity of ∼4.2 mmol g"−"1 at 3.0 MPa and a temperature range of 298 ± 10 K. The same material exhibits an impressive hydrogen storage capacity of 1.75 wt% as well at 77 K and 100 kPa. Here, we also propose a mechanism for the formation of activated carbon from spent coffee grounds. At low temperatures, the material has two distinct types with low and high surface areas; however, activation at elevated temperatures drives off the low surface area carbon, leaving behind the porous high surface area activated carbon. (paper)

Desorption behaviour of polycyclic aromatic hydrocarbons after long-term storage of two harbour sludges from the port of Rotterdam, The Netherlands

KAUST Repository

Heister, Katja

2013-04-12

Purpose: The desorption behaviour of 16 polycyclic aromatic hydrocarbons (PAHs) in sludges from two sites of the port of Rotterdam, The Netherlands, which are designated to be stored in a subaqueous sludge depository, was investigated after a storage time of 14 years at 4 °C under anaerobic conditions in the dark, mimicking depository conditions. Such long-term storage is believed to effect the desorption of the PAHs. Materials and methods: Batch desorption experiments over a time period of 130 days were performed with the brackish Beerkanaal (BK) sludge and the freshwater Beneden Merwede River (BMR) sludge. The organic carbon-water partitioning coefficient (K OC) values were calculated and compared to values of a previous study on the same sludges after a storage time of 3 years and to values obtained from calculations based on octanol-water partitioning coefficient (K OW) values. Additionally, the organic matter of the sludges was characterised by C and N elemental analysis and solid-state 13C nuclear magnetic resonance spectroscopy. Results and discussion: Only desorption of low molecular weight PAHs up to pyrene was detected. Several K OC values were higher compared to the values from the previous study, and all were increased compared to values based on K OW values. It is assumed that the increase in K OC was an effect of the prolonged contact time, causing slow intradomain diffusion of PAHs into the condensed carbon domains. Desorption was higher in BK than in BMR, which is explained by differences in organic matter composition because BMR (containing predominantly aromatic carbon) and BK (which was dominated by lipids) contained the same amount of organic carbon. It is inferred that lipids compete with PAHs for sorption sites on the aromatic carbon, so that lipids block these sorption sites, and the PAHs are adsorbed to the lipids. Conclusions: Since the amounts of PAHs desorbed from both sludges in this study were so low, it is supposed that long-term

Chemical and proteolysis-derived changes during long-term storage of lactose-hydrolyzed ultrahigh-temperature (UHT) milk.

Science.gov (United States)

Jansson, Therese; Jensen, Hanne B; Sundekilde, Ulrik K; Clausen, Morten R; Eggers, Nina; Larsen, Lotte B; Ray, Colin; Andersen, Henrik J; Bertram, Hanne C

2014-11-19

Proteolytic activity in milk may release bitter-tasting peptides and generate free amino terminals that react with carbohydrates, which initiate Maillard reaction. Ultrahigh temperature (UHT) heat treatment inactivates the majority of proteolytic enzymes in milk. In lactose-hydrolyzed milk a β-galactosidase preparation is applied to the milk after heat treatment, which has proteolytic side activities that may induce quality deterioration of long-term-stored milk. In the present study proteolysis, glycation, and volatile compound formation were investigated in conventional (100% lactose), filtered (60% lactose), and lactose-hydrolyzed (<1% lactose) UHT milk using reverse phase high-pressure liquid chromatography-mass spectrometry, proton nuclear magnetic resonance, and gas chromatography-mass spectrometry. Proteolysis was observed in all milk types. However, the degree of proteolysis was significantly higher in the lactose-hydrolyzed milk compared to the conventional and filtered milk. The proteins most prone to proteolysis were β-CN and αs1-CN, which were clearly hydrolyzed after approximately 90 days of storage in the lactose-hydrolyzed milk.

Long-term data series relating to Southern Africa's renewable natural resources

CSIR Research Space (South Africa)

Macdonald, IAW

1988-01-01

Full Text Available agricultural and veterinary data series. The remaining five chapters are of a more synthetic nature and examine the topics of palaeoenvironmental changes, environmental-forcing mechanisms, linkages between ecosyterns, the analysis and storage of long-term data...

Long term governance for radioactive waste management. Final report of Cowan2 - work package 4

International Nuclear Information System (INIS)

Schneider, Th.; Schieber, C.; Lavele, S.

2006-12-01

This report aims at identifying key features for the long term governance of radioactive waste. It is proposed by the COWAN2 Work Package 4 the purpose of which was to identify, discuss and analyse the institutional, ethical, economic and legal considerations raised by long term radioactive waste storage or disposal on the three interrelated issues of: responsibility and ownership of radioactive waste on the long term, continuity of local dialogue between stakeholders and monitoring of radioactive waste management facilities, and compensation and sustainable development. The aim is also to propose guidelines in order to better address long term issues in decision-making processes and start long term governance

Long term governance for radioactive waste management. Final report of Cowan2 - work package 4

Energy Technology Data Exchange (ETDEWEB)

Schneider, Th.; Schieber, C.; Lavele, S.

2006-12-15

This report aims at identifying key features for the long term governance of radioactive waste. It is proposed by the COWAN2 Work Package 4 the purpose of which was to identify, discuss and analyse the institutional, ethical, economic and legal considerations raised by long term radioactive waste storage or disposal on the three interrelated issues of: responsibility and ownership of radioactive waste on the long term, continuity of local dialogue between stakeholders and monitoring of radioactive waste management facilities, and compensation and sustainable development. The aim is also to propose guidelines in order to better address long term issues in decision-making processes and start long term governance

Quality changes of Antarctic krill powder during long term storage

DEFF Research Database (Denmark)

Nielsen, Nina Skall; Lu, Henna Fung Sieng; Bruheim, Inge

2017-01-01

of packaging in vacuum was observed. The stability was assessed by changes in concentrations of lipid classes, antioxidants, pyrroles and lipid, and Strecker-derived volatiles. Some degradation occurred during storage at room temperature. Thus, a minor increase in volatiles, an increase in free fatty acids...... and a concomitant decrease in antioxidants, tocopherol, and astaxanthin was observed. In addition, there was a minor decrease in phospholipids and n-3 fatty acids; however, storage at vacuum improved the oxidative stability of krill powder. Practical applications: For the use of krill powder in human nutrition......, it is important, that the quality and stability is sufficiently high to retain the nutritional value during storage. This study contributes with information about the stability during storage up to 12 months at room temperature and the effect of packaging the powder in vacuum. Antarctic krill (Euphausia superba...

Endogenous BDNF is required for long-term memory formation in the rat parietal cortex.

Science.gov (United States)

Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

2005-01-01

Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

A new methodology involving stable isotope tracer to compare short- and long- term selenium mobility in soils

Science.gov (United States)

Tolu, Julie; Thiry, Yves; Potin-gautier, Martine; Le hécho, Isabelle; Bueno, Maïté

2013-04-01

Selenium is an element of environmental concern given its dual beneficial and toxic character to animal and human health. Its radioactive isotope 79Se, a fission product of 235U, is considered critical in safety assessment of nuclear waste repositories in case of leakage and hypothetical soil contamination. Therefore, Se species transformations and interactions with soil components have to be clearly understood to predict its dispersion in the biosphere (e.g., accumulation in soils, migration to waters, transfer to living organisms). While natural Se interactions with soils run over centuries to millennia time scales, transformations and partitioning are generally studied with short-term experiments (often inferior to 1 month) after Se addition. The influence of slower, long-term processes involved in Se speciation and mobility in soils is thus not properly accounted for. We tested if using ambient Se would be relevant for long-term risk assessment while added Se would be more representative of short-term contamination impact. For that purpose, we developed a new methodology to trace the differential reactivity of ambient and spiked Se at trace level (µg kg-1) in soils. It combined the use of a stable isotopically enriched tracer with our previous published analytical method based on specific extractions and HPLC-ICP-MS to determine trace Se species partition in different soil phases. Given that soil extracts contains very high concentrations of various elements interfering Se (e.g., Fe, Cl, Br), the ICP-MS parameters and mathematical corrections were optimized to cope with such interferences. Following optimization, three correct and accurate (<2%) isotope ratios were obtained with 77Se, 78Se, 80Se and 82Se. The optimized method was then applied to an arable and a forest soil submitted to an aging process (drying/wetting cycles) during three months, to which 77Se(IV) was previously added. The results showed that ambient Se was at steady state in terms of water

Working memory, long-term memory and language processing : issues and future directions

OpenAIRE

Collette, Fabienne; Van der Linden, Martial; Poncelet, Martine

2000-01-01

We examined different views of the relationships between working memory, long-term memory and language processing : working memory considered as a gateway between sensory input and long-term memory or rather as a workspace; working memory considered as not strictly tied to any particular cognitive system (and consequently viewed as separated from the language system) or rather as drawing on the operation and storage capacities of a subset of components involved in language processing. It is a...

Limitations and possibilities of green synthesis and long-term stability of colloidal Ag nanoparticles

Science.gov (United States)

Velgosová, Oksana; Mražíková, Anna

2017-12-01

In this paper the influence of algae life cycle and the solutions pH on the green synthesis of colloidal Ag nanoparticles (AgNPs) as well as effect of different storage conditions on AgNPs long-term stability was investigated. Silver nanoparticles were biologically synthesized using extracts of Parachlorella kessleri algae cultivated 1, 2, 3 and 4 weeks. The formation of AgNPs was monitored using a UV-vis spectrophotometer and verified by TEM observation. The results confirmed formation of polyhedron and/or near polyhedron AgNPs, ranging between 5 and 60 nm in diameter. The age of algae influenced the synthesis rate and an amount of AgNPs in solution. The best results were obtained using tree weeks old algae. UV-vis analysis and TEM observation also revealed that the size and the stability of AgNPs depend on the pH of solution. AgNPs formed in solutions of higher pH (8 and 10) are polyhedron, fine, with narrow size interval and stabile. Nanoparticles formed in solutions of low pH (2, 4 and 6) started to lose their stability on 10th day of experiment, and the particle size interval was wide. The long-term stability of AgNPs can be influenced by light and temperature conditions. The most significant stability loss was observed at day light and room temperature (21°C). After 200-days significant amount of agglomerated particles settled on the bottom of the Erlenmeyer flask. AgNPs stored at dark and room temperature showed better long-term stability, weak particles agglomeration was observed. AgNPs stored at dark and at temperature 5°C showed the best long-term stability. Such AgNPs remained spherical, fine (5-20 nm), with narrow size interval and stable (no agglomeration) even after more than six months.

Long-term disposal of enrichment plant tails

International Nuclear Information System (INIS)

1979-08-01

Approximately 97% of the uranium fed to the isotope separation plants is recovered as tails containing nominally 0.2 wt percent U-235. Essentially all this tails material produced in the past, as well as that currently being generated, is stored as solidified UF 6 in steel cylinders. This report describes a stand-alone, 10 tU/day facility for converting the UF 6 to a stable uranium oxide powder amenable to long-term storage in steel drums. The conversion is accomplished in a two-step process in which the UF 6 is first reduced to UF 4 with hydrogen in a tower reactor and then the UF 4 is pyrohydrolyzed to UO 2 with steam in a three-stage screw reactor. One reduction reactor supplies the feed for three pyrohydrolysis reactor lines. Included in the process flow sheets and reactor design details are descriptions of the major auxiliary components for vaporizing and feeding the UF 6 , a dissociator for ammonia used as a hydrogen source, a system for recovering anhydrous hydrogen fluoride, and a reactor system for the disposal of hydrous hydrogen fluoride. Two of the nominal 10 tU/day plants would be required to handle the tails produced in isotope separation plants supplying enriched uranium to a nuclear power industry with a generation capacity of 50 GWe per year

Radiation characteristics of spent fuel of heavy-water research reactor during long-term storage

International Nuclear Information System (INIS)

Gerasimov, A.S.; Kiselev, G.V.; Myrtsymova, L.A.; Zaritskaya, T.S.

2002-01-01

Decay heat power and radiotoxicity by water of actinides and fission products from spent fuel of heavy-water research reactor RA were calculated for period of storage during 300000 years. Three variants of fuel enrichment by 235 U were considered: 2%, 21%, and 80%. The mass of 235 U in one fuel element was supposed to be the same for all variants of enrichment. The decay heat power of fission products in initial period is about 20 times higher than that of actinides. Decay heat power and radiotoxicity of actinides do not practically decrease during long period of time as they are determined by nuclides with very long half-life periods. (author)

Heart rate at discharge and long-term prognosis following percutaneous coronary intervention in stable and acute coronary syndromes--results from the BASKET PROVE trial.

Science.gov (United States)

Jensen, Magnus Thorsten; Kaiser, Christoph; Sandsten, Karl Erik; Alber, Hannes; Wanitschek, Maria; Iversen, Allan; Jensen, Jan Skov; Pedersen, Sune; Soerensen, Rikke; Rickli, Hans; Zurek, Marzena; Fahrni, Gregor; Bertel, Osmund; De Servi, Stefano; Erne, Paul; Pfisterer, Matthias; Galatius, Søren

2013-10-09

Elevated heart rate (HR) is associated with mortality in a number of heart diseases. We examined the long-term prognostic significance of HR at discharge in a contemporary population of patients with stable angina (SAP), non-ST-segment elevation acute coronary syndromes (NSTE-ACS), and ST-segment elevation myocardial infarction (STEMI) revascularized with percutaneous coronary intervention (PCI). Patients from the BASKET-PROVE trial, an 11-center randomized all-comers trial comparing bare-metal and drug-eluting stenting in large coronary vessels, were included. Discharge HR was determined from a resting ECG. Long-term outcomes (7 days to 2 years) were evaluated for all-cause mortality and cardiovascular death and non-fatal myocardial infarction. A total of 2029 patients with sinus rhythm were included, 722 (35.6%) SAP, 647 (31.9%) NSTE-ACS, and 660 (32.5%) STEMI. Elevated discharge HR was associated significantly with all-cause mortality: when compared to a reference of 90 bpm. For cardiovascular death/myocardial infarction, a discharge HR >90 bpm was associated with a hazard ratio of 6.2 (2.5-15.5, pacute coronary syndromes an elevated discharge HR was independently associated with poor prognosis. Conversely, a HR <60 bpm at discharge was associated with a good long-term prognosis irrespective of indication for PCI. © 2013.

Box-Behnken analysis and storage of spray-dried collagenolytic proteases from Myceliophthora thermophila submerged bioprocess.

Science.gov (United States)

Hamin Neto, Youssef Ali Abou; Coitinho, Luciana Barbosa; de Freitas, Luis Alexandre Pedro; Cabral, Hamilton

2017-05-28

Enzymes do not have long-term storage stability in soluble forms, thus drying methods could minimize the loss of enzymatic activity, the spray dryer removes water under high temperatures and little time. The aims of this study were to improve the stability of enzymatic extract from Myceliophthora thermophila for potential applications in industry and to evaluate the best conditions to remove the water by spray drying technique. The parameters were tested according to Box-Behnken and evaluated by analysis of variance (ANOVA), all the parameters measured were found to influence the final enzyme activity and spray drying process yield ranged from 38.65 to 63.75%. Enzyme powders showed increased storage stability than extract and maintained about 100% of collagenolytic activity after 180 days of storage at 30°C. The results showed that the microbial enzymes maintained activity during the spray drying process and were stable during long-term storage; these are promising characteristics for industrial applications.

Marijuana effects on long-term memory assessment and retrieval.

Science.gov (United States)

Darley, C F; Tinklenberg, J R; Roth, W T; Vernon, S; Kopell, B S

1977-05-09

The ability of 16 college-educated male subjects to recall from long-term memory a series of common facts was tested during intoxication with marijuana extract calibrated to 0.3 mg/kg delta-9-tetrahydrocannabinol and during placebo conditions. The subjects' ability to assess their memory capabilities was then determined by measuring how certain they were about the accuracy of their recall performance and by having them predict their performance on a subsequent recognition test involving the same recall items. Marijuana had no effect on recall or recognition performance. These results do not support the view that marijuana provides access to facts in long-term storage which are inaccessible during non-intoxication. During both marijuana and placebo conditions, subjects could accurately predict their recognition memory performance. Hence, marijuana did not alter the subjects' ability to accurately assess what information resides in long-term memory even though they did not have complete access to that information.

A MODEL FOR PRODUCING STABLE, BROADBAND TERAHERTZ COHERENT SYNCHROTRON RADIATION IN STORAGE RINGS

International Nuclear Information System (INIS)

Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Martin, MichaelC.; Venturini, Marco

2003-01-01

We present a model for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use this model to optimize the performance of a source for CSR emission

Long-term monitoring of marine gas leakage

Science.gov (United States)

Spickenbom, Kai; Faber, Eckhard; Poggenburg, Jürgen; Seeger, Christian; Furche, Markus

2010-05-01

The sequestration of CO2 in sub-seabed geological formations is one of the Carbon Capture and Storage (CCS) strategies currently under study. Although offshore operations are significantly more expensive than comparable onshore operations, the growing public resistance against onshore CCS projects makes sub-seabed storage a promising option. Even after a thorough review of the geological setting, there is always the possibility of leakage from the reservoir. As part of the EU-financed project CO2ReMoVe (Research, Monitoring, Verification), which aims to develop innovative research and technologies for monitoring and verification of carbon dioxide geological storage, we are working on the development of submarine long-term gas flow monitoring systems. The basic design of the monitoring system builds on our experience in volcano monitoring. Early prototypes were composed of a raft floating on the surface of a mud volcano, carrying sensors for CO2 flux and concentration, data storage and transmission, and power supply by battery-buffered solar panels. The system was modified for installation in open sea by using a buoy instead of a raft and a funnel on the seafloor to collect the gas, connected by a flexible tube. This setup provides a cost-effective solution for shallow waters. However, a buoy interferes with ship traffic, and it is also difficult to adapt this design to greater water depths. These requirements can best be complied by a completely submersed system. A system for unattended long-term monitoring in a marine environment has to be extremely durable. Therefore, we focussed on developing a mechanically and electrically as simple setup as possible, which has the additional advantage of low cost. The system consists of a funnel-shaped gas collector, a sensor head and pressure housings for electronics and power supply. Since this setup is inexpensive, it can be deployed in numbers to cover larger areas. By addition of multi-channel data loggers, data

Defining sale ethylene for long term storage of tulip bulbs

NARCIS (Netherlands)

Wild, de H.P.J.; Peppelenbos, H.W.; Dijkstra, M.H.G.E.; Gude, H.

2002-01-01

The maximum ethylene level that can be permitted in storage rooms, without causing damage to tulip bulbs, is not exactly known. Therefore, a zero-tolerance for the presence of ethylene during storage of tulip bulbs is common practice. This results in excessive ventilation and coherent large energy

Geological storage of radioactive waste

International Nuclear Information System (INIS)

Barthoux, A.

1983-01-01

Certain radioactive waste contains substances which present, although they disappear naturally in a progressive manner, a potential risk which can last for very long periods, of over thousands of years. To ensure a safe long-term handling, provision has been made to bury it deep in stable geological structures which will secure its confinement. Radioactive waste is treated and conditioned to make it insoluble and is then encased in matrices which are to immobilize them. The most radioactive waste is thus incorporated in a matrix of glass which will ensure the insulation of the radioactive substances during the first thousands of years. Beyond that time, the safety will be ensured by the properties of the storage site which must be selected from now on. Various hydrogeological configurations have been identified. They must undergo detailed investigations, including even the creation of an underground laboratory. This document also presents examples of underground storage installations which are due to be built [fr

Controllable fabrication of large-scale hierarchical silver nanostructures for long-term stable and ultrasensitive SERS substrates

Science.gov (United States)

Wu, Jing; Fang, Jinghuai; Cheng, Mingfei; Gong, Xiao

2016-09-01

In this work, we aim to prepare effective and long-term stable hierarchical silver nanostructures serving as surface-enhanced Raman scattering (SERS) substrates simply via displacement reaction on Aluminum foils. In our experiments, Hexadecyltrimethylammonium bromide (CTAB) is used as cationic surfactant to control the velocity of displacement reaction as well as the hierarchical morphology of the resultant. We find that the volume ratio of CTAB to AgNO3 plays a dominant role in regulating the hierarchical structures besides the influence of displacement reaction time. These as-prepared hierarchical morphologies demonstrate excellent SERS sensitivity, structural stability and reproducibility with low values of relative standard deviation less than 20 %. The high SERS analytical enhancement factor of ~6.7 × 108 is achieved even at the concentration of Crystal Violet (CV) as low as 10-7 M, which is sufficient for single-molecule detection. The detection limit of CV is 10-9 M in this study. We believe that this simple and rapid approach integrating advantages of low-cost production and high reproducibility would be a promising way to facilitate routine SERS detection and will get wide applications in chemical synthesis.

Long-term stabilization considerations for decommissioned and reclaimed uranium sites

International Nuclear Information System (INIS)

Abt, S.R.; Nelson, J.D.; Johnson, T.L.

1988-01-01

The long-term stabilization of decommissioned uranium mill sites and of reclaimed uranium mill tailings sites encompass a broad spectrum of design capabilities. This paper presents a few of the quantitative methodologies recently developed or refined to evaluate physical factors (i.e. precipitation, fluvial geomorphology, stable slope, slope stabilization with riprap and riprap selection) that influence long-term stabilization of uranium mill and mill tailings sites. It is acknowledged that the degree of refinement of these methodologies are in their infancy and that extensive research and development are warranted to increase the level of assurance. However, these methodologies provide an initial guideline for evaluating long-term stabilization that has not been previously existed. The purpose of this paper is to present a review of currently available state-of-the-art engineering techniques and methodologies for the evaluation of reclamation plans designed to provide long-term stability against potential failure modes. In some cases, evaluative techniques have been developed for long-term stabilization where methodologies have not previously existed. Each methodology to be presented represents a starting point upon which additional research and/or development may be warranted

Evaluation of the Universal Viral Transport system for long-term storage of virus specimens for microbial forensics.

Science.gov (United States)

Hosokawa-Muto, Junji; Fujinami, Yoshihito; Mizuno, Natsuko

2015-08-01

Forensic microbial specimens, including bacteria and viruses, are collected at biocrime and bioterrorism scenes. Although it is preferable that the pathogens in these samples are alive and kept in a steady state, the samples may be stored for prolonged periods before analysis. Therefore, it is important to understand the effects of storage conditions on the pathogens contained within such samples. To evaluate the capacity to preserve viable virus and the viral genome, influenza virus was added to the transport medium of the Universal Viral Transport system and stored for over 3 months at various temperatures, after which virus titrations and quantitative analysis of the influenza hemagglutinin gene were performed. Although viable viruses became undetectable 29 days after the medium was stored at room temperature, viruses in the medium stored at 4°C were viable even after 99 days. A quantitative PCR analysis indicated that the hemagglutinin gene was maintained for 99 days at both 4°C and room temperature. Therefore, long-term storage at 4°C has little effect on viable virus and viral genes, so the Universal Viral Transport system can be useful for microbial forensics. This study provides important information for the handling of forensic virus specimens. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Long Term Storage of cytogenetic changes in liquidators of Chernobyl

International Nuclear Information System (INIS)

Karpov, V. B.

2004-01-01

At present chromosome aberration analysis in lymphocytes as well as micronucleus assay are most reliable methods of bio indication of radiation effects. The problem of persistent of cytogenetic changes during the long term after exposure is very important. The cytogenetic studies of liquidators residents of St. Petersburg and region revealed that the average chromosome aberration rate 4-5 years after the accident constitutes 4.94±0.38, number of aberrant cells was 4.82±0.36, dicentrics -0.23±0.10 per 100 cells, micronucleus number -46.1±2.1 per 100 cells that is significantly higher than in control group. dispersion analysis confirms the reported level of external exposure effects on chromosome aberration rate (?=0.04) in this group of liquidators. In 73 persons from the group of high risk participants of nuclear tests, nuclear submarine personnel 8-45 years after average number of chromosome aberrations was 6.5±0.32; dicentrics - 0.64±0.10, centric rings- 0.04±0.02 per 100 cells, for micronuclei -51.4±2.82 per thousand cells, that is significantly higher than in control group (p<0.01). In 45.2% cases the aberration markers (disentrics and centric rings) were found. The late cytogenetic effects were observed after decades and possibility to use these indicators for long term diagnosis is now under consideration. (Author)

Long-term mortality and causes of death associated with Staphylococcus aureus bacteremia

DEFF Research Database (Denmark)

Gotland, N; Uhre, M L; Mejer, N

2016-01-01

OBJECTIVES: Data describing long-term mortality in patients with Staphylococcus aureus bacteremia (SAB) is scarce. This study investigated risk factors, causes of death and temporal trends in long-term mortality associated with SAB. METHODS: Nationwide population-based matched cohort study...... respiratory disease, nervous system disease, unknown causes, psychiatric disorders, cardiovascular disease and senility. Over time, rates of death decreased or were stable for all disease categories except for musculoskeletal and skin disease where a trend towards an increase was seen. CONCLUSION: Long......-term mortality after SAB was high but decreased over time. SAB cases were more likely to die of eight specific causes of death and less likely to die of five other causes of death compared to controls. Causes of death decreased for most disease categories. Risk factors associated with long-term mortality were...

Mechanically stable ternary heterogeneous electrodes for energy storage and conversion.

Science.gov (United States)

Gao, Libo; Zhang, Hongti; Surjadi, James Utama; Li, Peifeng; Han, Ying; Sun, Dong; Lu, Yang

2018-02-01

Recently, solid asymmetric supercapacitor (ASC) has been deemed as an emerging portable power storage or backup device for harvesting natural resources. Here we rationally engineered a hierarchical, mechanically stable heterostructured FeCo@NiCo layered double hydroxide (LDH) with superior capacitive performance by a simple two-step electrodeposition route for energy storage and conversion. In situ scanning electron microscope (SEM) nanoindentation and electrochemical tests demonstrated the mechanical robustness and good conductivity of FeCo-LDH. This serves as a reliable backbone for supporting the NiCo-LDH nanosheets. When employed as the positive electrode in the solid ASC, the assembly presents high energy density of 36.6 W h kg -1 at a corresponding power density of 783 W kg -1 and durable cycling stability (87.3% after 5000 cycles) as well as robust mechanical stability without obvious capacitance fading when subjected to bending deformation. To demonstrate its promising capability for practical energy storage applications, the ASC has been employed as a portable energy source to power a commercially available digital watch, mini motor car, or household lamp bulb as well as an energy storage reservoir, coupled with a wind energy harvester to power patterned light-emitting diodes (LEDs).

Quality Changes During Long Term Farmers’ Stock Storage

Science.gov (United States)

Since 2012, U.S. annual peanut production has increased 44% from an average of 2.6 million MT compared with 1.8 million MT (1997 and 2012). This production increase has resulted in longer storage times between harvest and shelling. A study was conducted to observe the changes in quality of farmers...

Comparison of two humidification systems for long-term noninvasive mechanical ventilation.

Science.gov (United States)

Nava, S; Cirio, S; Fanfulla, F; Carlucci, A; Navarra, A; Negri, A; Ceriana, P

2008-08-01

There is no consensus concerning the best system of humidification during long-term noninvasive mechanical ventilation (NIMV). In a technical pilot randomised crossover 12-month study, 16 patients with stable chronic hypercapnic respiratory failure received either heated humidification or heat and moisture exchanger. Compliance with long-term NIMV, airway symptoms, side-effects and number of severe acute pulmonary exacerbations requiring hospitalisation were recorded. Two patients died. Intention-to-treat statistical analysis was performed on 14 patients. No significant differences were observed in compliance with long-term NIMV, but 10 out of 14 patients decided to continue long-term NIMV with heated humidification at the end of the trial. The incidence of side-effects, except for dry throat (significantly more often present using heat and moisture exchanger), hospitalisations and pneumonia were not significantly different. In the present pilot study, the use heated humidification and heat and moisture exchanger showed similar tolerance and side-effects, but a higher number of patients decided to continue long-term noninvasive mechanical ventilation with heated humidification. Further larger studies are required in order to confirm these findings.

Spent fuel, plutonium and nuclear waste: long-term management; Le combustible use et le plutonium en tant que dechets nucleaires: gestion a long terme

Energy Technology Data Exchange (ETDEWEB)

Collard, G

1998-11-01

Different options for the management of nuclear waste arising from the nuclear fuel cycle are discussed. Special emphasis is on reprocessing followed by geological disposal, geological disposal of reprocessing waste, direct geological disposal of spent nuclear fuel, long term storage. Particular emphasis is on the management of plutonium including recycling, immobilisation and disposal, partitioning and transmutation.

Corrosion inhibition studies in support of the long term storage of AGR fuel

Energy Technology Data Exchange (ETDEWEB)

Standring, P [Sellafield Limited (United Kingdom)

2012-07-01

Thorp Receipt and Storage (at Sellafield, UK) is currently being investigated as a bridging solution for the storage of AGR fuel pending the out-come of a national review into spent fuel management. AGR spent fuel is known to be susceptible to corrosion through inter-granular attack. To avoid this, the chosen storage regime for AGR fuel is sodium hydroxide dosed pond water to pH 11.4; now 22 years of operating experience. The conversion of TR and S will require a phased transition. During this transition sodium hydroxide cannot be used due to materials compatibility issues. Alternative corrosion inhibitors have been investigated as an interim measure and sodium nitrate has been selected as a suitable candidate. The efficiency of sodium nitrate to inhibit propagating inter-granular attack of active AGR materials has yet to be established. In the longer term sodium hydroxide will be deployed along with a move to a closed loop pond water management system. Given that carbon dioxide is known to be absorbed by sodium hydroxide dosed water and can affect fuel integrity, in the case of Magnox fuel, there is a need to establish its impact on AGR fuel. The objectives are: To establish the impact of carbonate on AGR fuel corrosion; To establish the efficiency of sodium nitrate to inhibit propagating inter-granular attack of irradiated AGR materials.

Study on behaviour in long term of vitrified materials

International Nuclear Information System (INIS)

Vernaz, E.

1993-01-01

In collaboration with EDF (Electricite de France), after testing fusion of Refiom (Residus d'Epuration des Fumees d'Incineration d'Ordures Menageres), residues from purification of incineration smokes of household rubbish, realised at Porcheville and at the Laboratory of Renardieres with experimental processing of vitrification by plasma, CEA (Centre d'Etudes Atomiques), atomic center of research, began study on resistance in long term of vitrified products. From about thirty five years, CEA carries out research to confine radioactive waste of high activity in stable materials. Glass was the first best one which allowed to incorporate about thirty different chemical elements found in fission products solutions into a stable die with a good chemical durability; three vitrification shops raised, one at Marcoule ('AVM', 1978) in the south of France, the two other ones at La Hague ('R7', 1989 and 'T7', 1992) in Normandy. To determine a possible impact of a deep radioactive waste disposal on human and environment, several studies began. In particular, studies on aqueous corrosion of glasses to determine behaviour in long term of glass package (first barrier of confinement) and to estimate kinetics of releasing confined toxical elements on periods of several thousands years. Principal results are exposed in this conference. Experience shows that safety analysis cannot be based on long term extrapolation of a simple lixiviation result. This analysis must include: a sufficient knowledge in basic mechanisms of alteration to predict the kinetic evolution in a long term. To take in account environment conditions with a normal or accidental scheme (acidity, clay, organic compounds,...). This knowledge broadly developed by CEA for nuclear glasses seems to be easily transposable to different wastes (industrial ones or from hospitals) and takes place in a contract of research CEA/EDF to valorize vitrified products. 9 figs. 4 refs

Stable lithium electrodeposition in liquid and nanoporous solid electrolytes

KAUST Repository

Lu, Yingying

2014-08-10

Rechargeable lithium, sodium and aluminium metal-based batteries are among the most versatile platforms for high-energy, cost-effective electrochemical energy storage. Non-uniform metal deposition and dendrite formation on the negative electrode during repeated cycles of charge and discharge are major hurdles to commercialization of energy-storage devices based on each of these chemistries. A long-held view is that unstable electrodeposition is a consequence of inherent characteristics of these metals and their inability to form uniform electrodeposits on surfaces with inevitable defects. We report on electrodeposition of lithium in simple liquid electrolytes and in nanoporous solids infused with liquid electrolytes. We find that simple liquid electrolytes reinforced with halogenated salt blends exhibit stable long-term cycling at room temperature, often with no signs of deposition instabilities over hundreds of cycles of charge and discharge and thousands of operating hours. We rationalize these observations with the help of surface energy data for the electrolyte/lithium interface and impedance analysis of the interface during different stages of cell operation. Our findings provide support for an important recent theoretical prediction that the surface mobility of lithium is significantly enhanced in the presence of lithium halide salts. Our results also show that a high electrolyte modulus is unnecessary for stable electrodeposition of lithium.

Thermal Analysis of the SAFKEG Package for Long Term Storage

International Nuclear Information System (INIS)

NARENDRA, GUPTA

2005-01-01

Interim plutonium storage for up to 10 years in the K-reactor building is currently being planned at Savannah River Site (SRS). SAFKEG package could be used to store Pu metal and oxide (PuO2) in the K-reactor complex with other packagings like 9975. The SAFKEG is designed for carrying Type-B materials across the DOE complex and meets the 10CFR71 requirements. Thermal analyses were performed to ensure that the temperatures of the SAFKEG components will not exceed their temperature limits under the K-reactor storage conditions. Thermal analyses of the SAFKEG packaging with three content configurations using BNFL 3013 outer container (Rocky Flats, SRS bagless transfer cans, and BNFL inner containers) were performed for storage of PuO2 and plutonium metal

N-terminal pro-B-type natriuretic peptide and long-term mortality in stable coronary heart disease

DEFF Research Database (Denmark)

Kragelund, Charlotte; Grønning, Bjørn; Køber, Lars

2005-01-01

quartile was 2.4 (95 percent confidence interval, 1.5 to 4.0; Pfamily history with respect to ischemic heart disease; the presence or absence of a history......-term mortality in patients with stable coronary disease and provides prognostic information above and beyond that provided by conventional cardiovascular risk factors and the degree of left ventricular systolic dysfunction....

Form-stable paraffin/high density polyethylene composites as solid-liquid phase change material for thermal energy storage: preparation and thermal properties

International Nuclear Information System (INIS)

Sari, Ahmet

2004-01-01

This paper deals with the preparation of paraffin/high density polyethylene (HDPE) composites as form-stable, solid-liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted paraffin because of providing structural strength. Therefore, it is named form-stable composite PCM. In this study, two kinds of paraffins with melting temperatures of 42-44 deg. C (type P1) and 56-58 deg. C (type P2) and latent heats of 192.8 and 212.4 J g -1 were used. The maximum weight percentage for both paraffin types in the PCM composites without any seepage of the paraffin in the melted state were found as high as 77%. It is observed that the paraffin is dispersed into the network of the solid HDPE by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 37.8 and 55.7 deg. C, and 147.6 and 162.2 J g -1 , respectively, by the technique of differential scanning calorimetry (DSC). Furthermore, to improve the thermal conductivity of the form-stable P/HDPE composite PCMs, expanded and exfoliated graphite (EG) by heat treatment was added to the samples in the ratio of 3 wt.%. Thereby, the thermal conductivity was increased about 14% for the form-stable P1/HDPE and about 24% for the P2/HDPE composite PCMs. Based on the results, it is concluded that the prepared form-stable P/HDPE blends as composite type PCM have great potential for thermal energy storage applications in terms of their satisfactory thermal properties and improved thermal conductivity. Furthermore, these composite PCMs added with EG can be considered cost effective latent heat storage materials since they do not require encapsulation and extra cost to enhance

Sleep facilitates long-term face adaptation.

Science.gov (United States)

Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

2013-10-22

Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation--which are usually not considered to play a relevant role in mnemonic processes--with learning and memory, and at the same time reveal a new function of sleep in cognition.

Long-term L-Triiodothyronine (T3) treatment in stable systolic heart failure patients

DEFF Research Database (Denmark)

Holmager, Pernille; Schmidt, Ulla; Mark, Peter

2015-01-01

%, range: 37-52 and serum T3 levels 1·4 nmol/l (0·9-1·6). The T3 dose was 20 μg per day (10-40). TSH levels did not change between groups, whereas serum T3 levels increased in the active arm. Cardiac function as measured by LVEF, end-diastolic and end-systolic volumes and cardiac output did not change...... during T3-treatment and neither did the neurohormonal profile. There were no side-effects in terms of cardiac arrhythmias and no change in resting heart rate. CONCLUSIONS: This study does not support the hypothesis that oral T3 treatment might be beneficial to patients with chronic, stable systolic HF...

Dry storage of Magnox fuel

International Nuclear Information System (INIS)

1986-09-01

This work, commissioned by the CEGB, studies the feasibility of a combination of short-term pond storage and long-term dry storage of Magnox spent fuel as a cheaper alternative to reprocessing. Storage would be either at the reactor site or a central site. Two designs are considered, based on existing design work done by GEC-ESL and NNC; the capsule design developed by NNC and with storage in passive vaults for up to 100 yrs and the GEC-ESL tube design developed at Wylfa for the interim storage of LWR. For the long-term storage of Magnox spent fuel the GEC-ESL tubed vault all-dry storage method is recommended and specifications for this method are given. (U.K.)

Long-term survival of Naegleria polaris from Antarctica after 10 years of storage at 4 °C.

Science.gov (United States)

Matsuo, Junji; Nakamura, Shinji; Okubo, Torahiko; Fukui, Manabu; Yamaguchi, Hiroyuki

2018-03-01

A free-living amoeba, Naegleria is ubiquitously distributed in various natural environments. Since some Naegleria spp. are exclusively distributed in the Arctic and sub-Antarctic regions, we hypothesized that the amoeba may be useful to determine long-term survival of Naegleria in laboratory conditions at 4 °C. The main objective of the study is to determine that a species of an environmental amoebal isolated can live at low temperatures after a long time. Here, we therefore show long-term survival of an amoeba, Naegleria polaris isolated from a sediment sample, which was collected from Antarctica 10 years ago, and since stored at 4 °C. The sample was put on non-nutrient agar plates with heat-killed Escherichia coli, and then the plate was incubated at 4, 15, or 30 °C. Motile amoebae were seen only when the plate was incubated at 15 °C. The sequencing of ribosomal DNA including internal transcribed spacers (ITS) 1, 5.8S rDNA, and ITS2 region revealed the amoebae to be N. polaris, which is exclusively distributed in the Arctic and sub-Antarctic regions. Scanning electron microscopic observation showed that no typical sucker-like structure was seen on the surface of N. polaris, but the cysts were similar to those of Naegleria fowleri. Thus, our result shows, for the first time, that N. polaris can survive after 10 years of storage at 4 °C. This finding may help us understand the still undescribed effects of environmental samples on viability of amoebae.

Long term storage of finished gasolines in large salt caverns

Energy Technology Data Exchange (ETDEWEB)

Koenig, J.W.J. [German Strategic Petroleum Reserve, Hamburg (Germany)

1995-05-01

Strategic oil stocking requires large low cost storage facilities. Crude oil has been held in very large salt mines and/or artificially made salt caverns for many years, notably in Europe and the USA. Following crude oil, gasoils and refinery light feed stocks have been tried also. Military organisations tried jet fuel and early cases of underground aviation gasoline storage in steel tanks have been reported.

Calcium induces long-term legacy effects in a subalpine ecosystem.

Directory of Open Access Journals (Sweden)

Urs Schaffner

Full Text Available Human activities have transformed a significant proportion of the world's land surface, with profound effects on ecosystem processes. Soil applications of macronutrients such as nitrate, phosphorus, potassium or calcium are routinely used in the management of croplands, grasslands and forests to improve plant health or increase productivity. However, while the effects of continuous fertilization and liming on terrestrial ecosystems are well documented, remarkably little is known about the legacy effect of historical fertilization and liming events in terrestrial ecosystems and of the mechanisms involved. Here, we show that more than 70 years after the last application of lime on a subalpine grassland, all major soil and plant calcium pools were still significantly larger in limed than in unlimed plots, and that the resulting shift in the soil calcium/aluminium ratio continues to affect ecosystem services such as primary production. The difference in the calcium content of the vegetation and the topmost 10 cm of the soil in limed vs. unlimed plots amounts to approximately 19.5 g m(-2, equivalent to 16.3% of the amount that was added to the plots some 70 years ago. In contrast, plots that were treated with nitrogen-phosphorus-potassium fertilizer in the 1930s did not differ from unfertilized plots in any of the soil and vegetation characteristics measured. Our findings suggest that the long-term legacy effect of historical liming is due to long-term storage of added calcium in stable soil pools, rather than a general increase in nutrient availability. Our results demonstrate that single applications of calcium in its carbonated form can profoundly and persistently alter ecosystem processes and services in mountain ecosystems.

Physico-chemical properties of ready to eat, shelf-stable pasta during storage.

Science.gov (United States)

Carini, E; Curti, E; Cassotta, F; Najm, N E O; Vittadini, E

2014-02-01

The changes in physico-chemical properties of RTE shelf stable pasta were studied during storage with a multianalytical and multidimensional approach (with special focus on water status) to understand the ageing process in this product. Pasta hardness and amylopectin recrystallisation increased, macroscopic water status indicators and proton molecular translational mobility remained constant, and significant changes were measured in the proton rotational molecular mobility indicators ((1)H FID, (1)H T2) during storage. Since the main changes observed in RTE pasta during storage were similar to those observed in other cereal-based products, it would be interesting to verify the effect of the anti-staling methods commonly used in the cereal processing industry in improving RTE pasta shelf-stability. Copyright © 2013 Elsevier Ltd. All rights reserved.

Relapse rates after psychotherapy for depression - stable long-term effects? A meta-analysis.

Science.gov (United States)

Steinert, Christiane; Hofmann, Mareike; Kruse, Johannes; Leichsenring, Falk

2014-10-01

Depression is the most common mental disorder. Effective psychotherapeutic treatments for depression exist; however, data on their long-term effectiveness beyond a time span of two years is still scarce. Our aim was to perform a meta-analysis, investigating (a) overall rates of relapse more than two years after psychotherapy (meta-analysis 1), and (b) if psychotherapy has more enduring effects than non-psychotherapeutic comparison conditions (e.g. pharmacotherapy, treatment as usual), again beyond a time span of two years post-therapy (meta-analysis 2). We searched electronic databases Medline, PsycINFO and the COCHRANE Library. Main selection criteria were (i) RCT of psychotherapy with follow-up interval of more than 2 years, (ii) primary diagnosis of depression, assessed by observer ratings, (iii) report of relapse at follow-up. We identified 11 studies, 6 of which included a non-psychotherapeutic comparison condition. Together they comprised long-term data of 966 patients. Mean follow-up duration was 4.4 years. The overall relapse rate at long-term follow-up was 0.39 (95% CI 0.29, 0.50). Psychotherapy resulted in significantly less relapses (53.1% vs. 71.1%, OR 0.51; 95% CI 0.32, 0.82, p=0.005) than comparison treatments. This finding corresponded to a number needed to treat (NNT) of 5.55. Results can only be preliminary as data was sparse and studies differed methodologically. Heterogeneity in the first meta-analysis was high (I(2)=82%). Results indicated publication bias. The relapse rate more than two years after psychotherapy is relatively high, but significantly lower compared to non-psychotherapeutic treatments. Multiannual follow-ups should routinely be included in future psychotherapy RCTs. Copyright © 2014 Elsevier B.V. All rights reserved.

Long-term retrievability and safeguards for immobilized weapons plutonium in geologic storage

Energy Technology Data Exchange (ETDEWEB)

Peterson, P.F. [Univ. of California, Berkeley, CA (United States)

1996-05-01

If plutonium is not ultimately used as an energy source, the quantity of excess weapons plutonium (w-Pu) that would go into a US repository will be small compared to the quantity of plutonium contained in the commercial spent fuel in the repository, and the US repository(ies) will likely be only one (or two) locations out of many around the world where commercial spent fuel will be stored. Therefore excess weapons plutonium creates a small perturbation to the long-term (over 200,000 yr) global safeguard requirements for spent fuel. There are details in the differences between spent fuel and immobilized w-Pu waste forms (i.e. chemical separation methods, utility for weapons, nuclear testing requirements), but these are sufficiently small to be unlikely to play a significant role in any US political decision to rebuild weapons inventories, or to change the long-term risks of theft by subnational groups.

Long-term retrievability and safeguards for immobilized weapons plutonium in geologic storage

International Nuclear Information System (INIS)

Peterson, P.F.

1996-01-01

If plutonium is not ultimately used as an energy source, the quantity of excess weapons plutonium (w-Pu) that would go into a US repository will be small compared to the quantity of plutonium contained in the commercial spent fuel in the repository, and the US repository(ies) will likely be only one (or two) locations out of many around the world where commercial spent fuel will be stored. Therefore excess weapons plutonium creates a small perturbation to the long-term (over 200,000 yr) global safeguard requirements for spent fuel. There are details in the differences between spent fuel and immobilized w-Pu waste forms (i.e. chemical separation methods, utility for weapons, nuclear testing requirements), but these are sufficiently small to be unlikely to play a significant role in any US political decision to rebuild weapons inventories, or to change the long-term risks of theft by subnational groups

How much suspended particulate matter enters long-term in-channel storage?

Science.gov (United States)

Dietrich, Stephan; Kleisinger, Carmen; Kehl, Nora; Schubert, Birgit; Hillebrand, Gudrun

2017-04-01

The route of suspended particulate matter (SPM) downstream rivers strongly depends on discharge conditions and involves transport times and periods with resting times in deposits e.g. at areas with low-flow conditions near the channel bed. It is, however, difficult to estimate the contribution of SPM on the bed load. In this study, particle-bound polychlorinated biphenyls (PCB), which were released by an incident in the Elbe river (Central Europe) in spring 2015, could be used as unique tracer for transport pathways of SPM along the whole river stretch (over 700 km length), including low mountain ranges, lowlands, and the estuary. In 2015 the Elbe River was characterized by low-discharge conditions. Thus, the export of SPM on flood plains was strongly limited. The incident was monitored by concentration measurements of seven indicator PCB congeners along the inland part of the Elbe River as well as in the Elbe estuary. Data from ten monitoring stations (settling tanks) are considered. The total PCB load is calculated for all stations on the basis of monthly contaminant concentrations and daily suspended sediment concentrations. Monte-Carlo simulations assess the uncertainties of the calculated load. It is shown that the ratio of high versus low chlorinated PCB congeners is a suitable tracer to distinguish the PCB load of the incident from the long-term background signal (hereafter PCB6 ratio). We demonstrate that both the load of PCB as well as its chemical fingerprint allows the estimation of transport durations for the transport processes involved. Only a little part of the suspension has been transported via wash load. The PCB6 ratio is used to estimate mean transport velocities of the wash load fraction. A direct transport of wash load via the mean flow velocity of the water was not observed. Shortly after the incident, the PCB6 ratio was monitored 257 km downstream of the incident site in April 2015, in May first occurrence was monitored 514 km downstream of

Technical and economic assessments of storage techniques for long-term retention of industrial-beet sugar for non-food industrial fermentations

Science.gov (United States)

Vargas-Ramirez, Juan Manuel

Industrial beets may compete against corn grain as an important source of sugars for non-food industrial fermentations. However, dependable and energy-efficient systems for beet sugar storage and processing are necessary to help establish industrial beets as a viable sugar feedstock. Therefore, technical and economic aspects of beet sugar storage and processing were evaluated. First, sugar retention was evaluated in whole beets treated externally with either one of two antimicrobials or a senescence inhibitor and stored for 36 wk at different temperature and atmosphere combinations. Although surface treatment did not improve sugar retention, full retention was enabled by beet dehydration caused by ambient air at 25 °C and with a relative humidity of 37%. This insight led to the evaluation of sugar retention in ground-beet tissue ensiled for 8 wk at different combinations of acidic pH, moisture content (MC), and sugar:solids. Some combinations of pH ≤ 4.0 and MC ≤ 67.5% enabled retentions of at least 90%. Yeast fermentability was also evaluated in non-purified beet juice acidified to enable long-term storage and partially neutralized before fermentation. None of the salts synthesized through juice acidification and partial neutralization inhibited yeast fermentation at the levels evaluated in that work. Conversely, yeast fermentation rates significantly improved in the presence of ammonium salts, which appeared to compensate for nitrogen deficiencies. Capital and operating costs for production and storage of concentrated beet juice for an ethanol plant with a production capacity of 76 x 106 L y-1 were estimated on a dry-sugar basis as U.S. ¢34.0 kg-1 and ¢2.2 kg-1, respectively. Storage and processing techniques evaluated thus far prove that industrial beets are a technically-feasible sugar feedstock for ethanol production.

Long-term solar activity and terrestrial connections. Part I: theory

Directory of Open Access Journals (Sweden)

N. D. Diamantides

1998-05-01

Full Text Available The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun – either now or in the past, the long-term behavior of such phenomena is ultimately "connected" to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concept's pertinence to a number of terrestrial phenomena.Key words. Solar activity · Kolmogorov algorithm

Self-assembled air-stable magnesium hydride embedded in 3-D activated carbon for reversible hydrogen storage.

Science.gov (United States)

Shinde, S S; Kim, Dong-Hyung; Yu, Jin-Young; Lee, Jung-Ho

2017-06-01

The rational design of stable, inexpensive catalysts with excellent hydrogen dynamics and sorption characteristics under realistic environments for reversible hydrogen storage remains a great challenge. Here, we present a simple and scalable strategy to fabricate a monodispersed, air-stable, magnesium hydride embedded in three-dimensional activated carbon with periodic synchronization of transition metals (MHCH). The high surface area, homogeneous distribution of MgH 2 nanoparticles, excellent thermal stability, high energy density, steric confinement by carbon, and robust architecture of the catalyst resulted in a noticeable enhancement of the hydrogen storage performance. The resulting MHCH-5 exhibited outstanding hydrogen storage performance, better than that of most reported Mg-based hydrides, with a high storage density of 6.63 wt% H 2 , a rapid kinetics loading in hydrogenation compared to that of commercial MgH 2 . The origin of the intrinsic hydrogen thermodynamics was elucidated via solid state 1 H NMR. This work presents a readily scaled-up strategy towards the design of realistic catalysts with superior functionality and stability for applications in reversible hydrogen storage, lithium ion batteries, and fuel cells.

A review at the role of storage in energy systems with a focus on Power to Gas and long-term storage

NARCIS (Netherlands)

Blanco, Herib; Faaij, André

2018-01-01

A review of more than 60 studies (plus more than 65 studies on P2G) on power and energy models based on simulation and optimization was done. Based on these, for power systems with up to 95% renewables, the electricity storage size is found to be below 1.5% of the annual demand (in energy terms).

Furosemide Prescription During the Dry State Is a Predictor of Long-Term Survival of Stable, Optimally Medicated Patients With Systolic Heart Failure.

Science.gov (United States)

Sargento, Luis; Simões, Andre Vicente; Longo, Susana; Lousada, Nuno; Reis, Roberto Palma Dos

2017-05-01

Furosemide is associated with poor prognosis in patients with heart failure and reduced ejection fraction (HFrEF). To evaluate the association between daily furosemide dose prescribed during the dry state and long-term survival in stable, optimally medicated outpatients with HFrEF. Two hundred sixty-six consecutive outpatients with left ventricular ejection fraction failure therapy, were followed up for 3 years in a heart failure unit. The end point was all-cause death. There were no changes in New York Heart Association class and therapeutics, including diuretics, and no decompensation or hospitalization during 6 months. Furosemide doses were categorized as low or none (0-40 mg/d), intermediate (41-80 mg/d), and high (>80 mg). Cox regression was adjusted for significant confounders. The 3-year mortality rate was 33.8%. Mean dose of furosemide was 57.3 ± 21.4 mg/d. A total of 47.6% of patients received the low dose, 42.1% the intermediate dose, and 2.3% the high dose. Receiver operating characteristics for death associated with furosemide dose showed an area under the curve of 0.74 (95% confidence interval [CI]: 0.68-0.79; P 40 mg/d. An increasing daily dose of furosemide was associated with worse prognosis. Those receiving the intermediate dose (hazard ratio [HR] = 4.1; 95% CI: 2.57-6.64; P 40 mg/d, in a propensity score-matched cohort, had a greater risk of mortality than those receiving a low dose (HR = 4.02; 95% CI: 1.8-8.8; P = .001) and those not receiving furosemide (HR = 3.9; 95% CI: 0.07-14.2; P = .039). Furosemide administration during the dry state in stable, optimally medicated outpatients with HFrEF is unfavorably associated with long-term survival. The threshold dose was 40 mg/d.

Complex containment design for long-term encapsulation of radioactive waste

International Nuclear Information System (INIS)

Sungaila, M.A.; San, E.K.W.; Palmeter, T.

2011-01-01

The Port Granby Project is part of the larger Port Hope Area Initiative (PHAI), a community-based program for the development and implementation of a safe, local, long-term management solution for historic low-level radioactive waste in the Municipalities of Port Hope and Clarington. The Port Granby Project includes the construction of a long-term low-level radioactive waste management facility, the transfer of the contaminated material to the new facility from existing storage, construction and operation of a new waste water treatment facility, and monitoring and maintenance of the facility for a period of several hundred years. A key component of the new long-term facility is a highly-engineered containment mound incorporating a composite base liner, a leachate collection system, and a multi-layer final cover system. Issues of interest include the details of the design, the evolution of the design, as well as the field quality assurance measures that will be specified to ensure that the design is correctly implemented. (author)

Spent fuel storage - dry storage options and issues

International Nuclear Information System (INIS)

Akins, M.J.

2007-01-01

The increase in the number of nuclear energy power generation facilities will require the ability to store the spent nuclear fuel for a long period until the host countries develop reprocessing or disposal options. Plants have storage pools which are closely associated with the operating units. These are excellent for short term storage, but require active maintenance and operations support which are not desirable for the long term. Over the past 25 years, dry storage options have been developed and implemented throughout the world. In recent years, protection against terrorist attack has become an increasing source of design objectives for these facilities, as well as the main nuclear plant. This paper explores the current design options of dry storage cask systems and examines some of the current design issues for above ground , in-ground, or below-ground storage of spent fuel in dry casks. (author)

Highly stable supercapacitors with conducting polymer core-shell electrodes for energy storage applications

KAUST Repository

Xia, Chuan; Chen, Wei; Wang, Xianbin; Hedhili, Mohamed N.; Wei, Nini; Alshareef, Husam N.

2015-01-01

commercial application. Here, the development of nanostructured PAni-RuO2 core-shell arrays as electrodes for highly stable pseudocapacitors with excellent energy storage performance is reported. A thin layer of RuO2 grown by atomic layer deposition (ALD

The European FP7 ULTimateCO2 project: A comprehensive approach to study the long term fate of CO2 geological storage sites

Science.gov (United States)

Audigane, P.; Brown, S.; Dimier, A.; Pearce, J.; Frykman, P.; Maurand, N.; Le Gallo, Y.; Spiers, C. J.; Cremer, H.; Rutters, H.; Yalamas, T.

2013-12-01

The European FP7 ULTimateCO2 project aims at significantly advance our knowledge of specific processes that could influence the long-term fate of geologically stored CO2: i) trapping mechanisms, ii) fluid-rock interactions and effects on mechanical integrity of fractured caprock and faulted systems and iii) leakage due to mechanical and chemical damage in the well vicinity, iv) brine displacement and fluid mixing at regional scale. A realistic framework is ensured through collaboration with two demonstration sites in deep saline sandstone formations: the onshore former NER300 West Lorraine candidate in France (ArcelorMittal GeoLorraine) and the offshore EEPR Don Valley (former Hatfield) site in UK operated by National Grid. Static earth models have been generated at reservoir and basin scale to evaluate both trapping mechanisms and fluid displacement at short (injection) and long (post injection) time scales. Geochemical trapping and reservoir behaviour is addressed through experimental approaches using sandstone core materials in batch reactive mode with CO2 and impurities at reservoir pressure and temperature conditions and through geochemical simulations. Collection of data has been generated from natural and industrial (oil industry) analogues on the fluid flow and mechanical properties, structure, and mineralogy of faults and fractures that could affect the long-term storage capacity of underground CO2 storage sites. Three inter-related lines of laboratory experiments investigate the long-term evolution of the mechanical properties and sealing integrity of fractured and faulted caprocks using Opalinus clay of Mont Terri Gallery (Switzerland) (OPA), an analogue for caprock well investigated in the past for nuclear waste disposal purpose: - Characterization of elastic parameters in intact samples by measuring strain during an axial experiment, - A recording of hydraulic fracture flow properties by loading and shearing samples in order to create a 'realistic

Long-term storage of three unconventional oils

Directory of Open Access Journals (Sweden)

Hussein, Ismail H.

2008-03-01

Full Text Available Three samples, Sclerocarya birrea oil (SCO, Melon bug oil (Aspongubus viduatus (MBO, and Sorghum bug oil (Agonoscelis pubescens (SBO, were stored (autoxidized in the dark at 30±2 °C for 24 months. Oil aliquots were withdrawn every 2-4 month for analyses of changes in four quality indexes, namely fatty acid composition, tocopherol content, peroxide value and oxidative stability index by Rancimat. After 24 months of storage the fatty acid composition of the three oils showed no change while tocopherol contents were decreased. SCO and MBO showed only slight changes in their oxidative stability as indicated by the peroxide value and induction period during the 24 months of storage. Sorghum bug oil showed a periodical increase in the peroxide value and had less stability as measured by the Rancimat in comparison to other oils.Tres muestras de aceite, Sclerocarya birrea oil (SCO, Melon bug oil (Aspongubus viduatus (MBO, and Sorghum bug oil (Agonoscelis pubescens (SBO, fueron almacenadas en la oscuridad a 30±2 °C durante 24 meses. Cada 2- 4 meses se toman alícuotas para analizar los cambios de calidad. Se determinaron la composición en ácidos grasos, el contenido en tocoferol, el índice de peróxidos y la estabilidad oxidativa mediante el aparato Rancimat. Después de 24 meses de almacenamiento, la composición en ácidos grasos no experimentó variación mientras que el contenido en tocoferol disminuyó en los tres aceites. SCO y MBO mostraron cambios minoritarios como se comprobó por los indices de peroxides y estabilidad a los 24 meses. SBO fue el menos estable de los tres aceites.

Qualification of polysiloxanes for long-term storage of radioactive waste; Qualifizierung von Polysiloxanen fuer die langzeitstabile Konditionierung radioaktiver Abfaelle

Energy Technology Data Exchange (ETDEWEB)

Kucharczyk, P.

2005-12-15

At present German policy envisages interim storage of all radioactive waste (for approximately 30 years) until a final repository is available. This therefore leads to higher standards for storage containers. Silicone elastomers (polysiloxanes), materials on the basis of silicon and oxygen with organic substituents, have various physical and chemical properties and seem to be suitable for the long-term storage of low- and intermediate-level radioactive waste. The aim of the present work is the qualification of a new coating material for storage containers. The use of polysiloxanes in other applications was also investigated. An important criterion for the coating is the simplicity of its application. Moreover, it should also have a high adhesion on steel as well as providing protection against corrosion. These properties were investigated for different polysiloxanes. The spraying tests showed that polysiloxane material with a viscosity of up to 45 000 mPas could be applied by the airless spraying method. An elastic coating was produced which could ensure protection against mechanical impacts. In the framework of water vapour experiments, a very high diffusion constant was determined. The corrosion test confirmed that the polysiloxane coating provided only insufficient corrosion protection if the sample was in contact with water and water vapour at the same time. This problem was solved by using an additional priming coat of 60 {mu}m zinc paint. The adhesion test showed that polysiloxanes have different levels of adhesion. The best adhesion was determined for condensation-cured silicones. The addition-cured materials had a lower adhesion, which was improved by the application of a priming coat. The outcome of these investigations is a wide spectrum of applications for polysiloxanes which can be used as firmly adhering coatings or removable decontamination layers. (orig.)

Storage of long lived solid waste

International Nuclear Information System (INIS)

Ozarde, P.D.; Agarwal, K.; Gupta, R.K.; Gandhi, K.G.

2009-01-01

Long lived solid waste, generated during the fuel cycle mainly includes high level vitrified waste product, high level cladding hulls and low and intermediate level alpha wastes. These wastes require storage in specially designed engineered facilities before final disposal into deep geological repository. Since high-level vitrified waste contain heat generating radionuclides, the facility for their storage is designed for continuous cooling. High level cladding hulls undergo volume reduction by compaction and will be subsequently stored. (author)

The French program on the spent nuclear fuel long term evolution: Major results, uncertainties and new requirements

International Nuclear Information System (INIS)

Ferry, Cecile; Poinssot, Christophe; Gras, Jean-Marie

2006-01-01

The 1991 Radioactive Waste Management Act established a framework in France for research activities on nuclear waste. Within this context, the Commissariat a l'Energie Atomique initiated a research program in 1999 to investigate the long-term behaviour of commercial spent nuclear fuel under the PRECCI project (from the French acronym for Research Project on Long-Term Evolution of Spent Fuel Packages), supported by the French electrical utility EDF and partially by FRAMATOME ANP. The scientific and technical studies performed within the project aim to address the operational issues of the spent fuel end-of-life. Within the context of the law which ends in 2006, the major part of the studies focused on the behaviour of the spent fuel (SF) in interim long-term dry storage and deep geological disposal. The operational questions initially identified concern (i) the retrievability of spent fuel assemblies at the end of the interim period of storage, (ii) the feasibility of treatment after the period of storage, (iii) the radionuclide source terms for SF in storage and geological disposal and (iv) the compatibility between storage and a subsequent geological disposal. Therefore the long-term evolution of the irradiated fuel is studied under the various boundary conditions encountered during storage and geological disposal: - in a closed system; this condition corresponds to the nominal scenario during storage and to the first confinement phase in disposal conditions (with a duration of 10,000 years in the reference scenario); - it consists in assessing the effects of the residual temperature and high radioactivity on the chemical and physical properties of the spent fuel pellets; - some of the studies are also dedicated to the mechanical behaviour of the cladding and structural materials of the assemblies; - in air, it refers to an incidental loss of confinement during storage or to a breaching of the canister before the site re-saturation in geological disposal

Long term plan of atomic energy development and utilization

International Nuclear Information System (INIS)

1982-01-01

The atomic energy utilization and development in Japan have progressed remarkably, and already nuclear power generation has borne an important part in electric power supply, while radiation has been utilized in the fields of industry, agriculture, medicine and so on. Now, atomic energy is indispensable for national life and industrial activity. The former long term plan was decided in September, 1978, and the new long term plan should be established since the situation has changed largely. The energy substituting for petroleum has been demanded, and the expectation to nuclear power generation has heightened because it enables stable and economical power supply. The independently developed technology related to atomic energy must be put in practical use. The peaceful utilization of atomic energy must be promoted, while contributing to the nuclear non-proliferation policy. The Atomic Energy Commission of Japan decided the new long term plan to clearly show the outline of the important measures related to atomic energy development and utilization in 10 years hereafter, and the method of its promotion. The basic concept of atomic energy development and utilization, the long term prospect and the concept on the promotion, the method of promoting the development and utilization, and the problems of funds, engineers and location are described. (kako, I.)

Long-term preservation of bacon by high energy electrons

International Nuclear Information System (INIS)

Hannah, K.W.; Simic, M.G.

1985-01-01

Extra long-term storage of frozen, vacuum packed, cured bacon can be achieved by electronation, using 3 MeV electrons generated by an electron accelerator. A combination process consisting of low nitrite curing (40 ppm), smoking, vacuum packaging in Saran plastic, electronation (1 to 3 Mrad), and freezing (-10 C) allows storage for at least 2 1/2 years without any noticeable loss in quality, e.g. color, appearance, smell, or taste. This process also eliminates microbiological hazards associated with Salmonella and C. botulinum. Six Mrad tons/hour throughput of a 3 MeV 50 kw electron beam accelerator for standard sliced bacon packaging indicates a practical and economic commercial use for this combination process. (author)

Fluorescent multiple staining and CASA system to assess boar sperm viability and membranes integrity in short and long-term extenders.

Science.gov (United States)

Lange-Consiglio, A; Meucci, A; Cremonesi, F

2013-01-01

The aim of this study was to assess the effect on boar spermatozoa quality of in vitro storage in short and long-term extenders by fluorescent multiple staining (FMS) and computer assisted semen analyzer (CASA). Fresh ejaculates from three healthy, sexually mature boars were diluted with equal volumes of six short-term or three long-term commercial extenders and stored at 19°C for 6 days (short-term) or 12 days (long-term). The integrity of spermatozoa membranes was analyzed by FMS using propidium iodide, 5,5',6,6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) and fluorescein isothiocyanate-conjugated peanut agglutinin (PNA). The results obtained from this staining were compared with spermatozoa motility assessed by CASA. Our study showed that the number of viable spermatozoa with non-reacted acrosomes and intact mitochondria was positively correlated with the rate of motile spermatozoa (r(2)>0.9) irrespective of the extender used. In all extenders the number of motile spermatozoa significantly decreased as preservation period increased (P<0.05). FMS test is a potent indicator of sperm motility because it analyses mitochondrial integrity independently from observable alterations in motility. The best performing extenders were BTS for short-term storage and TRI-x-Cell for long-term storage.

Coccidian oöcysts as type-specimens: long-term storage in aqueous potassium dichromate solution preserves DNA.

Science.gov (United States)

Williams, R B; Thebo, P; Marshall, R N; Marshall, J A

2010-05-01

Preservation of the exogenous oöcyst stage of coccidian parasites (phylum Apicomplexa N.D. Levine, 1970) as type-specimens of newly described species has long been problematical. Conventional fixatives have proved unsatisfactory, and compromises such as embedding oöcysts in resin or photographing them are not entirely appropriate for various reasons. As an alternative, chilled potassium dichromate solution (normally used in the laboratory to prevent putrefaction of temporary preparations of live oöcysts) has been tested as a long-term preservative of sporulated oöcysts of Eimeria brunetti P.P. Levine, 1942, E. maxima Tyzzer, 1929, E. mitis Tyzzer, 1929, E. necatrix Johnson, 1930, E. praecox Johnson, 1930 and E. tenella (Railliet & Lucet, 1891) (suborder Eimeriorina Léger, 1911; family Eimeriidae Minchin, 1903). Oöcysts from faeces of chickens Gallus gallus (Linnaeus) were placed in 2.5% w/v aqueous potassium dichromate solution (PDS) and stored in the dark at 4 +/- 2 degrees C. After 23 years in storage, oöcysts of each species were administered orally to chickens and failed to initiate infections, indicating that the oöcysts were dead. Nevertheless, after about 24 years, DNA was still recoverable from the oöcysts, and the original species identifications made by classic parasitological methods were confirmed by polymerase chain reaction assays. Furthermore, after almost 25 years, microscopical examination revealed that the walls and internal structures remained well preserved in 83-98% of the oöcysts of the six species investigated. Hence, PDS is potentially suitable for the long-term preservation of sporulated coccidian oöcysts as type-specimens for taxonomic purposes. The samples used in this study are now in the care of the Natural History Museum, London, UK. It is recommended that they be monitored in like manner, by suitably qualified scientists, at intervals of about 5 years to assess their state of preservation and the recoverability of DNA

Calcine Waste Storage at the Idaho Nuclear Technology and Engineering Center

Energy Technology Data Exchange (ETDEWEB)

M. D. Staiger

1999-06-01

A potential option in the program for long-term management of high-level wastes at the Idaho Nuclear Technology and Engineering Center (INTEC), at the Idaho National Engineering and Environmental Laboratory, calls for retrieving calcine waste and converting it to a more stable and less dispersible form. An inventory of calcine produced during the period December 1963 to May 1999 has been prepared based on calciner run, solids storage facilities operating, and miscellaneous operational information, which gives the range of chemical compositions of calcine waste stored at INTEC. Information researched includes calciner startup data, waste solution analyses and volumes calcined, calciner operating schedules, solids storage bin capacities, calcine storage bin distributor systems, and solids storage bin design and temperature monitoring records. Unique information on calcine solids storage facilities design of potential interest to remote retrieval operators is given.

Long-term sealing of openings in salt formations

International Nuclear Information System (INIS)

Walter, F.; Stockmann, N.; Yaramanci, U.; Laurens, J.F.

1993-01-01

Radioactive wastes can be disposed of in deep salt formations. Rock salt is a suitable geologic medium because of its unique characteristics. Open boreholes, shafts and drifts are created to provide physical access to the repository. Long-term seals must be emplaced in those potential pathways to prevent radioactive release to the biosphere. The sealing materials must be mechanically and, most important, geochemically stable within the host rock. Salt bricks made of compressed salt-powder are understood to be the first choice long-term sealing material. Seals built from salt bricks will be ductile. The permeability of the salt bricks is assumed to be in the order of 2*10 -15 m 2 . Large sealing systems are built by combining the individual bricks with mortar. Raw materials for mortar are fine-grained halite powder and ground saliferous clay. The permeability of the mortar decreases with its salt content to approx. 2*10 -14 m 2 . Moistened saliferous clay may show temporary swelling. Sealing experiments will be carried out in the Asse salt mine. Long-term seals will be built into holes of 1 m diameter. The contact and merging of the brick-wall with the surrounding rock salt will be investigated in long-term tests. Within the in situ sealing program a number of geophysical methods are applied. Acoustic emission measurements are used to study the effects of high pressure gas injection and a geoelectrical observation program is aiming to estimate the permeability in and around the long-term seal. High frequency electromagnetic methods contribute to the knowledge of the petrophysical rock properties. 11 refs., 12 figs

Interaction of Inhibitory and Facilitatory Effects of Conditioning Trials on Long-Term Memory Formation

Science.gov (United States)

Hosono, Shouhei; Matsumoto, Yukihisa; Mizunami, Makoto

2016-01-01

Animals learn through experience and consolidate the memories into long-time storage. Conditioning parameters to induce protein synthesis-dependent long-term memory (LTM) have been the subject of extensive studies in many animals. Here we found a case in which a conditioning trial inhibits or facilitates LTM formation depending on the intervals…

Behavior of high burnup fuel rod cladding during long-term dry storage in CASTOR casks

International Nuclear Information System (INIS)

Schaberg, A.; Spilker, H.; Goll, W.

2000-01-01

Short-time creep and rupture tests were performed to assess the strain potential of cladding of high burnt rods under conditions of dry storage. The tests comprised optimized Zr y-4 cladding samples from fuel rods irradiated to burnups of up to 64 MWd/kg U and were carried out at temperatures of 573 and 643 K at cladding stresses of about 400 and 600 MPa. The stresses, much higher than those occurring in a fuel rod, were chosen to reach circumferential elongations of about 2% within an envisaged testing time of 3-4 days. The creep tests were followed by a low temperature test at 423 K and 100 MPa to assess the long-term behavior of the cladding ductility especially with regard to the effect of a higher hydrogen content in the cladding due to the high burnup. The creep tests showed considerable uniform plastic elongations at these high burnups. It was demonstrated that around 600 K a uniform plastic strain of a least 2% is reached without cladding failure. The low temperature tests at 423 K for up to 5 days revealed no cladding failure under these conditions of reduced cladding ductility. It can be concluded that the increased hydrogen content has no adverse effect on cladding performance. (Authors)

Data needs for long-term dry storage of LWR fuel. Interim report

International Nuclear Information System (INIS)

Einziger, R.E.; Baldwin, D.L.; Pitman, S.G.

1998-04-01

The NRC approved dry storage of spent fuel in an inert environment for a period of 20 years pursuant to 10CFR72. However, at-reactor dry storage of spent LWR fuel may need to be implemented for periods of time significantly longer than the NRC's original 20-year license period, largely due to uncertainty as to the date the US DOE will begin accepting commercial spent fuel. This factor is leading utilities to plan not only for life-of-plant spent-fuel storage during reactor operation but also for the contingency of a lengthy post-shutdown storage. To meet NRC standards, dry storage must (1) maintain subcriticality, (2) prevent release of radioactive material above acceptable limits, (3) ensure that radiation rates and doses do not exceed acceptable limits, and (4) maintain retrievability of the stored radioactive material. In light of these requirements, this study evaluates the potential for storing spent LWR fuel for up to 100 years. It also identifies major uncertainties as well as the data required to eliminate them. Results show that the lower radiation fields and temperatures after 20 years of dry storage promote acceptable fuel behavior and the extension of storage for up to 100 years. Potential changes in the properties of dry storage system components, other than spent-fuel assemblies, must still be evaluated

Late protein synthesis-dependent phases in CTA long-term memory: BDNF requirement

Directory of Open Access Journals (Sweden)

Araceli eMartínez-Moreno

2011-09-01

Full Text Available It has been proposed that long-term memory persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related long-term memory when protein synthesis was inhibited. Our previous studies on the insular cortex (IC, a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA, have demonstrated that intracortical delivery of BDNF reverses the deficit in CTA memory caused by the inhibition of IC protein synthesis due to anisomycin administration during early acquisition. In this work, we first analyze whether CTA memory storage is protein synthesis dependent in different time-windows. We observed that CTA memory become sensible to protein synthesis inhibition 5 and 7 hours after acquisition. Then, we explore the effect of BDNF delivery (2 μg/2 μl per side in the IC during those late protein synthesis-dependent phases. Our results show that BDNF reverses the CTA memory deficit produced by protein synthesis inhibition in both phases. These findings support the notion that recurrent rounds of consolidation-like events take place in the neocortex for maintenance of CTA memory trace and that BDNF is an essential component of these processes.

Rapid fabrication of superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film with excellent energy-release characteristics and long-term storage stability

Energy Technology Data Exchange (ETDEWEB)

Ke, Xiang; Zhou, Xiang, E-mail: zhouxiang@njust.edu.cn; Hao, Gaozi; Xiao, Lei; Liu, Jie; Jiang, Wei, E-mail: superfine_jw@126.com

2017-06-15

Highlights: • Superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film is prepared by combining electrophoretic deposition and surface modification technologies. • The deposition system and kinetics of electrophoretic deposition process are investigated to optimize parameters to obtain smooth films. • Energy-release characteristics of superhydrophobic films are significantly improved for both fresh and aged samples. • Superhydrophobic films exhibit excellent long-time storage stability both in natural and accelerated aging test. • A preignition reaction is found to enhance the energy-release characteristics of superhydrophobic nanothermite film. - Abstract: One of the challenges for the application of energetic materials is their energy-retaining capabilities after long-term storage. In this study, we report a facile method to fabricate superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film by combining electrophoretic deposition and surface modification technologies. Different concentrations of dispersion solvents and additives are investigated to optimize the deposition parameters. Meanwhile, the dependence of deposition rates on nanoparticle concentrations is also studied. The surface morphology and chemical composition are characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. A static contact angles as high as 156° shows the superhydrophobicity of the nanothermite film. Natural and accelerated aging tests are performed and the thermal behavior is analyzed. Thermal analysis shows that the surface modification contributes to significantly improved energy-release characteristics for both fresh and aged samples, which is supposed to be attributed to the preignition reaction between Al{sub 2}O{sub 3} shell and FAS-17. Superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film exhibits excellent long-time storage stability with 83.4% of energy left in

Issues for the long term management of radioactive waste

International Nuclear Information System (INIS)

Schneider, T.; Schieber, C.; Lavelle, S.

2006-01-01

High-level radioactive waste are currently managed in interim storage installations, providing an adequate protection of the public and the workers for the short term period. However, the long-term persistence of the radioactivity of the waste gives a new timescale dimension, never experimented by the society for the development of protection systems. In the framework of the European Commission research project 'COWAM-2' (COmmunity WAste Management) dedicated to the governance of radioactive waste management, the issues of 'long term governance' have been addressed by exploring the elements which can contribute to a better integration of the technical and societal time dimensions, taking into account technical, ethical, economic and organizational considerations. The originality of this project is to address the various issues within working groups involving stakeholders from different origins and European countries together with a research team. After a discussion on the time dimensions to be taken into account from the technical and societal perspective, this paper presents, mainly based on the findings of the COWAM-2 project, a brief analysis of the ethical criteria to be considered when future generations are concerned as well as some performance criteria regarding long term governance. Finally, it proposes a discussion on the interest for the radiation protection experts to engage a process with stakeholders concerned by radioactive waste management in order to favour the emergence of a sustainable management responding to the issues at stake and including radiation protection considerations for long term periods. (authors)

How much radiation dose, to whom? Long-term storage, surveillance, retrieval and long processes cause additional dose to employees; Wie viel Strahlendosis fuer wen? Lange Lagerung, Offenhaltung und ein langer Entsorgungsprozess bedeuten zusaetzliche Dosis fuer Beschaeftigte

Energy Technology Data Exchange (ETDEWEB)

Walther, Clemens [Hannover Univ. (Germany). Inst. fuer Radiooekologie und Strahlenschutz; Riemann, Moritz [Kiel Univ. (Germany). Lehrstuhl fuer Philosophie und Ethik der Umwelt

2017-09-01

In the case of final nuclear waste disposal there are concurrent interests with respect to radiation protection: The realization of a disposal option with minimum required follow-up care needs time causing additional radiation exposure for the employees, also the option of long-term storage, surveillance and retrieval possibilities cause additional dose to employees. The contribution discusses possible consideration of requests for the different options.

Stability of Beriplast P fibrin sealant: storage and reconstitution.

Science.gov (United States)

Eberhard, Ulrich; Broder, Martin; Witzke, Günther

2006-04-26

This study was performed to investigate the stability of Beriplast P fibrin sealant (FS) across a range of storage conditions, both pre- and post-reconstitution. Storage stability of the FS was evaluated during long-term refrigeration (24 months) with or without interim storage at elevated temperatures (40 degrees C for 1 week and 25 degrees C for 1 and 3 months). Stability of individual FS components was assessed by measuring: fibrinogen content, Factor XIII activity (FXIII), thrombin activity and aprotinin potency. The package integrity of each component was also checked (sterility testing, moisture content and pH). Storage stability was also evaluated by testing the reconstituted product for adhesion (tearing force testing after mixing the solutions) and sterility. Reconstitution stability was evaluated following 3-months' storage, for up to 50 h post-reconstitution using the same tests as for the storage stability investigations. Pre-defined specifications were met for fibrinogen content, Factor XIII activity, and thrombin activity, demonstrating storage stability. Package integrity and the functionality and sterility of the reconstituted product were confirmed throughout. Reconstitution stability was demonstrated for up to 50 h following reconstitution, in terms of both tearing force and sterility tests. In conclusion, the storage stability of Beriplast P was demonstrated over a range of 24-month storage schedules including interim exposure to elevated temperature, and the reconstituted product was stable for up to 50 h.

Long-term-consequence analysis of no action alternative 2

International Nuclear Information System (INIS)

Buck, J.W.; Bagaasen, L.M.; Staven, L.H.; Serne, R.J.

1996-07-01

This report is a supplement to the Waste Isolation Pilot Plant (WIPP) Disposal-Phase Supplemental Environmental Impact Statement. Data and information is described which pertains to estimated impacts from postulated long-term release of radionuclides and hazardous constituents from alpha-bearing wastes stored at major generator/storage sites after loss of institutional control (no action alternative 2). Under this alternative, wastes would remain at the generator sites and not be emplaced at WIPP

Scientific reference on the long time evolution of spent fuels; Referentiel scientifique sur l'evolution a long terme des combustibles uses

Energy Technology Data Exchange (ETDEWEB)

Ferry, C.; Poinssot, Ch.; Broudic, V.; Jegou, Ch.; Roudil, D.; Poulesquen, A.; Miserque, F. [CEA Saclay, Dept. de Physico-Chimie, 91 - Gif sur Yvette (France); Cappelaere, Ch. [CEA Saclay, Dept. des Materiaux pour le Nucleaire, 91 - Gif-sur-Yvette (France); Desgranges, L.; Garcia, Ph.; Piron, J.P. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d' Etudes des Combustibles; Lovera, P.; Marimbeau, P. [CEA Cadarache, 13 - Saint Paul lez Durance (France). Dept. d' Etudes des Reacteurs; Corbel, C. [CEA Saclay, Dept. de Recherche sur l' Etat Condense, les Atomes et les Molecules, 91 - Gif sur Yvette (France)

2005-03-15

This report is published in the framework of the 1991 French law for the nuclear waste management. The state of the art reported here concerns the long term evolution of spent fuel in the various environmental conditions corresponding to dry storage and geological disposal: closed system, air and water saturated medium. This review is based on the results of the french PRECCI project (Research Program on Long term Evolution of Spent Nuclear Fuel) and on literature data. (authors)

Creation of Long-Term Coherent Optical Memory via Controlled Nonlinear Interactions in Bose-Einstein Condensates

International Nuclear Information System (INIS)

Zhang Rui; Garner, Sean R.; Hau, Lene Vestergaard

2009-01-01

A Bose-Einstein condensate confined in an optical dipole trap is used to generate long-term coherent memory for light, and storage times of more than 1 s are observed. Phase coherence of the condensate as well as controlled manipulations of elastic and inelastic atomic scattering processes are utilized to increase the storage fidelity by several orders of magnitude over previous schemes. The results have important applications for creation of long-distance quantum networks and for generation of entangled states of light and matter.

Long term storage in liquid nitrogen leads to only minor phenotypic and gene expression changes in the mammary carcinoma model cell line BT474.

Science.gov (United States)

Fazekas, Judit; Grunt, Thomas W; Jensen-Jarolim, Erika; Singer, Josef

2017-05-23

Cancer cell lines are indispensible surrogate models in cancer research, as they can be used off-the-shelf, expanded to the desired extent, easily modified and exchanged between research groups for affirmation, reproduction or follow-up experiments.As malignant cells are prone to genomic instability, phenotypical changes may occur after certain passages in culture. Thus, cell lines have to be regularly authenticated to ensure data quality. In between experiments these cell lines are often stored in liquid nitrogen for extended time periods.Although freezing of cells is a necessary evil, little research is performed on how long-term storage affects cancer cell lines. Therefore, this study investigated the effects of a 28-year long liquid nitrogen storage period on BT474 cells with regard to phenotypical changes, differences in cell-surface receptor expression as well as cytokine and gene expressional variations. Two batches of BT474 cells, one frozen in 1986, the other directly purchased from ATCC were investigated by light microscopy, cell growth analysis, flow cytometry and cytokine as well as whole-transcriptome expression profiling. The cell lines were morphologically indifferent and showed similar growth rates and similar cell-surface receptor expression. Transcriptome analysis revealed significant differences in only 26 of 40,716 investigated RefSeq transcripts with 4 of them being up-regulated and 22 down-regulated. This study demonstrates that even after very long periods of storage in liquid nitrogen, cancer cell lines display only minimal changes in their gene expression profiles. However, also such minor changes should be carefully assessed before continuation of experiments, especially if phenotypic alterations can be additionally observed.

Long-term solar activity and terrestrial connections. Part I: theory

Directory of Open Access Journals (Sweden)

N. D. Diamantides

Full Text Available The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun – either now or in the past, the long-term behavior of such phenomena is ultimately "connected" to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concept's pertinence to a number of terrestrial phenomena.

Key words. Solar activity · Kolmogorov algorithm

Long-term memory shapes the primary olfactory center of an insect brain.

Science.gov (United States)

Hourcade, Benoît; Perisse, Emmanuel; Devaud, Jean-Marc; Sandoz, Jean-Christophe

2009-10-01

The storage of stable memories is generally considered to rely on changes in the functional properties and/or the synaptic connectivity of neural networks. However, these changes are not easily tractable given the complexity of the learning procedures and brain circuits studied. Such a search can be narrowed down by studying memories of specific stimuli in a given sensory modality and by working on networks with a modular and relatively simple organization. We have therefore focused on associative memories of individual odors and the possible related changes in the honeybee primary olfactory center, the antennal lobe (AL). As this brain structure is organized in well-identified morpho-functional units, the glomeruli, we looked for evidence of structural and functional plasticity in these units in relation with the bees' ability to store long-term memories (LTMs) of specific odors. Restrained bees were trained to form an odor-specific LTM in an appetitive Pavlovian conditioning protocol. The stability and specificity of this memory was tested behaviorally 3 d after conditioning. At that time, we performed both a structural and a functional analysis on a subset of 17 identified glomeruli by measuring glomerular volume under confocal microscopy, and odor-evoked activity, using in vivo calcium imaging. We show that long-term olfactory memory for a given odor is associated with volume increases in a subset of glomeruli. Independent of these structural changes, odor-evoked activity was not modified. Lastly, we show that structural glomerular plasticity can be predicted based on a putative model of interglomerular connections.

Long Term Management of Spent Fuel from NEK

International Nuclear Information System (INIS)

Kegel, L.; Zeleznik, N.; Lokner, V.

2012-01-01

In 2008 Slovenian national agency for radioactive waste management ARAO started together with Croatian sister organization APO elaboration of a new revision of Decommissioning, Radioactive waste and Spent fuel management program for NPP Krsko. In scope of this work also new studies for spent fuel storage and disposal were prepared in which technical solutions were analyzed and proposed for specific spent fuel (SF) from NPP Krsko. Time schedules for main activities of SF disposal development were elaborated for two alternative scenarios which correspond to normal NPP Krsko operation and 20 - year lifetime extension. All technical activities were financially assessed and costs estimates of SF storage and geological disposal development provided. The prepared studies were verified by international experts in order to confirm the correctness of technical inputs, proposed solutions, time schedules of activities and costs evaluations. The calculated nominal and discounted costs of spent fuel management served for the recalculation of annuities in the integral scenarios of interrelated activities on NPP Krsko decommissioning, LILW and SF management. Besides new first proposal of long-term management of spent fuel from NPP Krsko the joint work also opened additional questions. One of this is time schedule of proposed activities for long term SF management - what were the criteria used in the determination of actions and are they optimal for both countries. How the process of site selection for SF storage or disposal should be prepared having in mind that it will bring many questions in both countries? Is direct disposal of SF still the best solution in current development of nuclear prospects? The paper will present the current development and solutions for SF management from NPP Krsko and will try to answer questions which need to be solved and future development in the SF management.(author).

Audit of long-term and short-term liabilities

Directory of Open Access Journals (Sweden)

Korinko M.D.

2017-03-01

Full Text Available The article determines the importance of long-term and short-term liabilities for the management of financial and material resources of an enterprise. It reviews the aim, objects and information generators for realization of audit of short-term and long-term obligations. The organizing and methodical providing of audit of long-term and short-term liabilities of an enterprise are generalized. The authors distinguish the stages of realization of audit of long-term and short-term liabilities, the aim of audit on each of the presented stages, and recommend methodical techniques. It is fixed that it is necessary to conduct the estimation of the systems of internal control and record-keeping of an enterprise by implementation of public accountant procedures for determination of volume and maintenance of selection realization. After estimating the indicated systems, a public accountant determines the methodology for realization of public accountant verification of long-term and short-term liabilities. The analytical procedures that public accountants are expedient to use for realization of audit of short-term and long-term obligations are determined. The authors suggest the classification of the educed defects on the results of the conducted public accountant verification of short-term and long-term obligations.

Non-stationarity driven by long-term change in catchment storage: possibilities and implications

Directory of Open Access Journals (Sweden)

J. D. Hughes

2015-06-01

Full Text Available "Non-stationarity" with reference to hydrology is a term applied to many situations (Milly et al., 2008. While climate change non-stationarity is often examined, these effects can provide a test for assumptions of runoff generation process impliedin rainfall–runoff (RR models. Observations from South-western Australia (SWA over the past 40 years show a decline in rainfall and reductions in runoff. Runoff and rainfall relationships in SWA show a significant shift over the past 40 years suggesting a change in runoff generation and catchment state. This has challenged the nature of assumed runoff generation process in SWA as well as the veracity of conceptual RR model structure. We expand on some of the lessons learned from SWA and discuss the climatic and geomorphic conditions that may make reasonable predictions of runoff very difficult with RR models calibrated in traditional ways. Catchment storage has a significant interaction with runoff generation and we examine the situations where these may change in the longer term. We suggest some strategies in terms of model structure and calibration that may improve predictive performance in such situations.

Defining a communication system for the long term

International Nuclear Information System (INIS)

Mitropoulou, Eleni

2015-01-01

Prof. Eleni Mitropoulou presented an ongoing study, undertaken on behalf of Andra, on long-term communication. The speaker highlighted that it is not so much the marking that needs to be sustainable, but above all what the marking communicates. She highlighted the importance of sustainable human action to produce memory and, thus, the need to reconcile the passive character of geological disposal and the active character of memory keeping. Focusing on semiotics, the interaction between the short, medium and long term was pointed out, highlighting the need to create a relay system. A multidimensional message was proposed, for the purposes of information ('storage site here'), interpellation (to warn, prevent or alert) and integration (with regard to the surrounding environment). This corresponds to the systemic approach of the RK and M initiative, which is based on a variety of RK and M transmission mechanisms that are integrated with and/or complement one another

Autonomous water sampling for long-term monitoring of trace metals in remote environments.

Science.gov (United States)

Kim, Hyojin; Bishop, James K B; Wood, Todd J; Fung, Inez Y

2012-10-16

A remotely controlled autonomous method for long-term high-frequency sampling of environmental waters in remote locations is described. The method which preserves sample integrity of dissolved trace metals and major ions for month-long periods employs a gravitational filtration system (GFS) that separates dissolved and particulate phases as samples are collected. The key elements of GFS are (1) a modified "air-outlet" filter holder to maximize filtration rate and thus minimize filtration artifacts; and (2) the direct delivery of filtrate to dedicated bottle sets for specific analytes. Depth and screen filter types were evaluated with depth filters showing best performance. GFS performance is validated using ground, stream, and estuary waters. Over 30 days of storage, samples with GFS treatment had average recoveries of 95 ± 19% and 105 ± 7% of Fe and Mn, respectively; without GFS treatment, average recoveries were only 16% and 18%. Dissolved major cations K, Mg, and Na were stable independent of collection methodology, whereas Ca in some groundwater samples decreased up to 42% without GFS due to CaCO(3) precipitation. In-field performance of GFS equipped autosamplers is demonstrated using ground and streamwater samples collected at the Angelo Coast Range Reserve, California from October 3 to November 4 2011.

Assessment of BED HIV-1 incidence assay in seroconverter cohorts: effect of individuals with long-term infection and importance of stable incidence.

Directory of Open Access Journals (Sweden)

Janet M McNicholl

Full Text Available BACKGROUND: Performance of the BED assay in estimating HIV-1 incidence has previously been evaluated by using longitudinal specimens from persons with incident HIV infections, but questions remain about its accuracy. We sought to assess its performance in three longitudinal cohorts from Thailand where HIV-1 CRF01_AE and subtype B' dominate the epidemic. DESIGN: BED testing was conducted in two longitudinal cohorts with only incident infections (a military conscript cohort and an injection drug user cohort and in one longitudinal cohort (an HIV-1 vaccine efficacy trial cohort that also included long-term infections. METHODS: Incidence estimates were generated conventionally (based on the number of annual serocoversions and by using BED test results in the three cohorts. Adjusted incidence was calculated where appropriate. RESULTS: For each longitudinal cohort the BED incidence estimates and the conventional incidence estimates were similar when only newly infected persons were tested, whether infected with CRF01_AE or subtype B'. When the analysis included persons with long-term infections (to mimic a true cross-sectional cohort, BED incidence estimates were higher, although not significantly, than the conventional incidence estimates. After adjustment, the BED incidence estimates were closer to the conventional incidence estimates. When the conventional incidence varied over time, as in the early phase of the injection drug user cohort, the difference between the two estimates increased, but not significantly. CONCLUSIONS: Evaluation of the performance of incidence assays requires the inclusion of a substantial number of cohort-derived specimens from individuals with long-term HIV infection and, ideally, the use of cohorts in which incidence remained stable. Appropriate adjustments of the BED incidence estimates generate estimates similar to those generated conventionally.

High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

Science.gov (United States)

Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

2015-10-21

An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.

Quantification of long-term wastewater fluxes at the surface water/groundwater-interface: an integrative model perspective using stable isotopes and acesulfame.

Science.gov (United States)

Engelhardt, I; Barth, J A C; Bol, R; Schulz, M; Ternes, T A; Schüth, C; van Geldern, R

2014-01-01

The suitability of acesulfame to trace wastewater-related surface water fluxes from streams into the hyporheic and riparian zones over long-term periods was investigated. The transport behavior of acesulfame was compared with the transport of water stable isotopes (δ(18)O or δ(2)H). A calibrated model based on a joint inversion of temperature, acesulfame, and piezometric pressure heads was employed in a model validation using data sets of acesulfame and water stable isotopes collected over 5months in a stream and groundwater. The spatial distribution of fresh water within the groundwater resulting from surface water infiltration was estimated by computing groundwater ages and compared with the predicted acesulfame plume obtained after 153day simulation time. Both, surface water ratios calculated with a mixing equation from water stable isotopes and simulated acesulfame mass fluxes, were investigated for their ability to estimate the contribution of wastewater-related surface water inflow within groundwater. The results of this study point to limitations for the application of acesulfame to trace surface water-groundwater interactions properly. Acesulfame completely missed the wastewater-related surface water volumes that still remained in the hyporheic zone under stream-gaining conditions. In contrast, under stream-losing conditions, which developed after periods of stagnating hydraulic exchange, acesulfame based predictions lead to an overestimation of the surface water volume of up to 25% in the riparian zone. If slow seepage velocities prevail a proportion of acesulfame might be stored in smaller pores, while when released under fast flowing water conditions it will travel further downstream with the groundwater flow direction. Therefore, under such conditions acesulfame can be a less-ideal tracer in the hyporheic and riparian zones and additional monitoring with other environmental tracers such as water stable isotopes is highly recommended. © 2013 Elsevier

One-step preparation of long-term stable and flexible CsPbBr3 perovskite quantum dots/ethylene vinyl acetate copolymer composite films for white LEDs.

Science.gov (United States)

Li, Yang; Lv, Ying; Guo, Ziquan; Dong, Liubing; Zheng, Jianghui; Chai, Chufen; Chen, Nan; Lu, Yijun; Chen, Chao

2018-04-19

CsPbBr3 perovskite quantum dots (PQDs)/ethylene vinyl acetate (EVA) composite films were prepared via a one-step method, based on that both supersaturated recrystallization of CsPbBr3 PQDs and dissolution of EVA were realized in toluene. The prepared films display outstanding green emitting performance with high color purity of 92% and photoluminescence quantum yield of 40.5% at appropriate CsPbBr3 PQD loading. They possess long-term stable luminescent properties in the air and in water, benefiting from the effective protection of CsPbBr3 PQDs by EVA matrix. Besides, the prepared CsPbBr3 PQDs/EVA films are flexible enough to be repeatedly bent for 1000 cycles while keeping unchanged photoluminescence intensity. Optical properties of the CsPbBr3 PQDs/EVA films in white LEDs were also studied by experiments and theoretical simulation. Overall, facile preparation process, good long-term stability and high flexibility allow our green-emitting CsPbBr3 PQDs/EVA films to be applied in lighting applications and flexible displays.

Fluorescent multiple staining and CASA system to assess boar sperm viability and membranes integrity in short and long-term extenders

Directory of Open Access Journals (Sweden)

F. Cremonesi

2013-03-01

Full Text Available The aim of this study was to assess the effect on boar spermatozoa quality of in vitro storage in short and long-term extenders by fluorescent multiple staining (FMS and computer assisted semen analyzer (CASA. Fresh ejaculates from three healthy, sexually mature boars were diluted with equal volumes of six short-term or three long-term commercial extenders and stored at 19°C for 6 days (short-term or 12 days (long-term. The integrity of spermatozoa membranes was analyzed by FMS using propidium iodide, 5,5’,6,6’-tetrachloro-1,1’,3,3’ tetraethylbenzimidazolyl-carbocyanine iodide (JC-1 and fluorescein isothiocyanate-conjugated peanut agglutinin (PNA. The results obtained from this staining were compared with spermatozoa motility assessed by CASA. Our study showed that the number of viable spermatozoa with non-reacted acrosomes and intact mitochondria was positively correlated with the rate of motile spermatozoa (r2>0.9 irrespective of the extender used. In all extenders the number of motile spermatozoa significantly decreased as preservation period increased (P<0.05. FMS test is a potent indicator of sperm motility because it analyses mitochondrial integrity independently from observable alterations in motility. The best performing extenders were BTS for short-term storage and TRI-x-Cell for long-term storage.

Impact of different cryoprotectants on the survival of freeze-dried Lactobacillus rhamnosus and Lactobacillus casei/paracasei during long-term storage.

Science.gov (United States)

Jofré, A; Aymerich, T; Garriga, M

2015-01-01

The production of long shelf-life highly concentrated dried probiotic/starter cultures is of paramount importance for the food industry. The aim of the present study was to evaluate the protective effect of glucose, lactose, trehalose, and skim milk applied alone or combined upon the survival of potentially probiotic Lactobacillus rhamnosus CTC1679, Lactobacillus casei/paracasei CTC1677 and L. casei/paracasei CTC1678 during freeze-drying and after 39 weeks of storage at 4 and 22 °C. Immediately after freeze-drying, the percentage of survivors was very high (≥ 94%) and only slight differences were observed among strains and cryoprotectants. In contrast, during storage, survival in the dried state depended on the cryoprotectant, temperature and strain. For all the protectants assayed, the stability of the cultures was remarkably higher when stored under refrigeration (4 °C). Under these conditions, skim milk alone or supplemented with trehalose or lactose showed the best performance (reductions ≤ 0.9 log units after 39 weeks of storage). The lowest survival was observed during non-refrigerated storage and with glucose and glucose plus milk; no viable cells left at the end of the storage period. Thus, freeze-drying in the presence of appropriate cryoprotectants allows the production of long shelf-life highly concentrated dried cultures ready for incorporation in high numbers into food products as starter/potential probiotic cultures.

Engineered Materials for Cesium and Strontium Storage Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Sean M. McDeavitt

2010-04-14

Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation and decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at

Engineered Materials for Cesium and Strontium Storage. Final Technical Report

International Nuclear Information System (INIS)

McDeavitt, Sean M.

2010-01-01

Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation and decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at Purdue

Long-term follow-up study and long-term care of childhood cancer survivors

Directory of Open Access Journals (Sweden)

Hyeon Jin Park

2010-04-01

Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.

Long term contracts signed in Slovak timber business

International Nuclear Information System (INIS)

Haluza, I.

2005-01-01

The Slovak timber business is changing. The state-owned company, SR Forests, which cuts more then 50% of Slovak timber has signed long term agreements with major domestic timber processing companies - Smrecina, the Rettenmeier Tatra Timber saw mill in Liptovsky Mikulas and two paper mills - Mondi SCP Ruzomberok and Kappa Sturovo. In the past, only quarterly contracts were signed. Now, for the first time, two-year contracts have been signed that should help the timber processing industry and the forestry sector. The General Director of Lesy SR (SR Forests), Karol Vins, hopes for better sale prices. Company headquarters wants to maintain better control of prices than under the old system of timber sales by its branches. In the opinion of the General Director of the Forestry Section at the Ministry of Agriculture, long term contracts will guarantee a stable delivery of timber to processing companies, giving investors in new production capacity a better position in negotiations with banks regarding financing. According to K. Vins, long term contracts have so far only been negotiated with major timber processing companies which are mostly controlled by foreign capital and therefore have good payment discipline. The Association of the Timber Processing Industry is unhappy regarding developments and Lesy SR has not invited domestic companies to these negotiations

Plutonium storage criteria

Energy Technology Data Exchange (ETDEWEB)

Chung, D. [Scientech, Inc., Germantown, MD (United States); Ascanio, X. [Dept. of Energy, Germantown, MD (United States)

1996-05-01

The Department of Energy has issued a technical standard for long-term (>50 years) storage and will soon issue a criteria document for interim (<20 years) storage of plutonium materials. The long-term technical standard, {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides,{close_quotes} addresses the requirements for storing metals and oxides with greater than 50 wt % plutonium. It calls for a standardized package that meets both off-site transportation requirements, as well as remote handling requirements from future storage facilities. The interim criteria document, {open_quotes}Criteria for Interim Safe Storage of Plutonium-Bearing Solid Materials{close_quotes}, addresses requirements for storing materials with less than 50 wt% plutonium. The interim criteria document assumes the materials will be stored on existing sites, and existing facilities and equipment will be used for repackaging to improve the margin of safety.