Single Canister Research Articles

Fully analytical solution in time and space domains on temperature in multi-barrier nuclear waste repository

Temperature evolution is one of the crucial factors in safe operation and geometric design of high-level radioactive waste disposal repositories. A three-dimensional two-layer axisymmetric heat transfer model was established to study the temperature evolution of the repository in the case of single canister. Applying a series of mathematical tools such as the finite Fourier sine transform, separation of variables and Duhamel's theorem, a fully analytical solution was obtained, which can visually and quickly represent the temperature evolution in both time and space. The validity of the model and solution was confirmed by comparing it with the existing line heat source solution, semi-analytical solution and finite element simulation results. The canister surface temperature was obtained by superimposing the temperature difference between the internal and external surfaces of buffer layer on the rock wall temperature. A single-panel calculation model was established, and dimensional and parameter analysis were carried out using the obtained fully analytical solution. According to the quantitative analysis using the obtained solution, increasing the canister spacing has a better effect on reducing the peak temperature than increasing the tunnel spacing. The effect of the two ways in reducing the peak temperature weakens with increasing the spacings.

Semianalytical Solution to Near-Field Temperature in Nuclear Waste Repository

The temperature field in a nuclear waste repository is an important issue with regard to the design and safety assessment of the repository. In this paper, a double-layer model for simulating the heat conduction near a single waste canister is established, and then, by applying the Laplace transform to the governing equations of the heat conduction in the buffer layer and the surrounding rock, the solutions of the temperature field are obtained in the Laplace domain. The temperature distribution near the nuclear waste canister is presented by numerical inversion of the solutions using Crump’s method in the time-space domain. Finally, the effects of parameters on the temperature on the canister surface are analyzed. The results show that the double-layer model of the heat conduction increases the maximum temperature on the canister surface by about 11.87°C compared to the single-layer model. The double-layer model is verified to be reliable by comparing with a line heat source model that has been verified by numerical calculations. The temperature on the canister surface is significantly affected by the burnup value and cooling time of the nuclear waste, the thickness of the buffer layer, the thermal conductivities of the buffer material and the surrounding rock, and the external boundary condition.

On the use of multicopters for sampling and analysis of volatile organic compounds in the air by adsorption/thermal desorption GC-MS

We describe a new approach for the determination of volatile organic compounds (VOCs) at precise locations in the air using active sampling on sorbent tubes outfitted to an inexpensive multicopter and analysis by thermal desorption (TD) gas chromatography-mass spectrometry (GC-MS). The aerial sampling method permits for the simultaneous collection of multiple air samples on separate TD tubes concurrently, increasing sample throughput compared to single canister sampling. Furthermore, the method is relatively inexpensive when compared to similar approaches, with overall costs below about $2000 (U.S. dollars). To demonstrate applicability, we measured VOCs at several heights near anthropogenic sources in the mid-south USA, including a municipal landfill, petroleum refinery, and a coal-fired power plant (CFPP), and within the canopy of a loblolly pine (Pinus taeda) forest. Concentrations of benzene, toluene, and xylene (BTX) were higher (p < 0.05) downwind of the refinery and CFPP compared to upwind. We observed both a unique mixture of VOCs at each site and higher concentrations of abundant VOCs downwind compared to upwind of the point sources and within versus above the forest canopy. Overall, this feasibility study demonstrates that highly maneuverable multicopters can be used to probe VOC concentrations aloft and thus have great potential to be utilized in unique sampling situations and for vertical profiling.

Effects of canister shot in the Civil War: skull of a soldier of the 54th Massachusetts Volunteers.

This skull (Fig. 1) was discovered in 1876 on Morris Island, South Carolina, near the site of Battery Wagner, a powerful fort that had protected the entrance to Charleston Harbor during the Civil War. The skull belonged to a man of African descent— most likely a soldier of the 54th Massachusetts Volunteers, which led the assault on Wagner on the night of July 18, 1863. Of approximately 600 men of the 54th who made the charge, 256 were killed, wounded, or missing. The 54th Massachusetts Volunteers was not the first black regiment in the Civil War, nor was it the first to fight. However, it was the first black regiment raised entirely of free men enrolled on the same terms as white troops and the first to engage in a major action well covered by the national press. Its gallant conduct in the doomed assault on Battery Wagner on July 18, 1863, electrified the nation and proved once and for all that the black man, given the opportunity, would fight as well as any white man. From the size of the wound, and what appear to be remains of the projectile itself, it can be surmised what type of munition hit this man: a canister ball from one of two field howitzers known to have been used in the repulse of that attack. Canister balls were made of iron; for the 6-lb gun, 1.17 inch in diameter, for the 12-lb field howitzer, 1.08 inch. The entry wound on the skull is approximately 1.18 inches across. Battery Wagner had no 6-lb guns, but did have two 12-lb field howitzers. In this case, it can be seen that a single canister ball has created a nearly round entry wound and a larger and more irregular fracture on the opposite side of the skull. Radiating fractures from the entrance and exit can be seen crossing the temporal, parietal, and frontal bones. The ball entered from rear left, traveled back to front and upwards,

Picking up grand vibrations The Particle at the End of the Universe How the Hunt for the Higgs Boson Leads Us to the Edge of a New World Sean Carroll Penguin, 2012. 380 pp.

![Figure][1] You are standing in the dark immensity of a tunnel stretching for miles before and behind you. It is colder than outer space, and vast superconducting magnets yawn above and flank you, sustained by 8000 kilometers' worth of wound cable. Every fragment of this colossal machine was crafted meticulously, in labs on every corner of the globe. At the flip of a switch, beams containing the energy of 175 metric tons of TNT will zoom around the tunnel, set to collide and explode in violent bursts of energy and light. Amazingly, all fuel for this endeavor comes from a single canister of hydrogen no larger than a fire extinguisher. Where are you? The Large Hadron Collider (LHC)—in the words of Sean Carroll, “the largest, most complex machine ever built by human beings.” In The Particle at the End of the Universe , Carroll embarks on an ambitious voyage through the quest to find the Higgs boson (more colorfully known as the “god particle”) from the development of modern physics, to the construction of the LHC, to the celebrated discovery of July 2012—and beyond. Carroll shines in his use of digestible language to communicate esoteric physics. Although keeping up fully might prove challenging for readers lacking any physics background, much insight can be gained from Carroll's analogies. He explains, for instance, that all “particles” are actually vibrations traveling in fundamental, invisible fields that permeate space, like sound waves propagating through the air. The collision of two particles to produce the Higgs boson is like two vibrating piano strings transferring their vibrations to a third. From the ancient Greeks, to gravity, to the billions of dark matter particles passing through our bodies each second, to the extra dimensions of string theory, the book is a pedagogical tour de force, complete with ample diagrams and appendices. ![Figure][1] Installing the ATLAS calorimeter. PHOTO: ATLAS EXPERIMENT © 2014 CERN The author establishes the human element of the “high stakes drama” surrounding the Higgs boson discovery and announcement in tandem with the scientific. Throughout his narrative, Carroll weaves a sense of the consuming passion that drives physicists on the “emotional roller-coaster ride” of fundamental research. He paints a rich mosaic—peppered with personal details, famous quips, and anecdotes—of the major players in physics over the centuries. The book includes poignant details such as the fact that Peter Higgs's seminal paper was initially rejected for publication and the emotion visible on Higgs's face during the standing ovation that followed the announcement that the LHC had found his eponymous boson. Perhaps the book's strongest facet is its triumphant championing of basic scientific research. Carroll's aim is broad and sweeping: to establish the central importance of science in humanity's wrestle with the question of existence. He terms the finding of the Higgs boson a “success for the human race” in answering our “restless desire to understand our world.” The Particle at the End of the Universe illustrates that finding it “is its own reward,” emphasizes the “universality of the scientific impulse,” and waxes poetic in juxtaposing art and science. The vast behemoth of modern physics, the LHC, and the scintillating discovery of the Higgs boson are not only important because they illumine the “secrets of the Universe”—the entire effort tells us something profound about ourselves. [1]: pending:yes

Finite Element Analysis of Transient Heat Transfer in and around a Deep Geological Repository for a Spent Nuclear Fuel Disposal Canister and the Heat Generation of the Spent Nuclear Fuel

This paper presents a finite element analysis of transient heat transfer in and around a hypothetical deep geological repository for a spent nuclear fuel (SNF) disposal canister and the heat generation of the SNF inside the canister to provide basic information for dimensioning the repository and configuring the repository components. Three geometric models are compared to determine the most suitable assuming the periodic allocation of boreholes where canisters are deposited. These models consist of several different material regions. Each model is horizontally limited to a region around and including a single canister, bounded by midsurfaces with variant distances between adjacent deposition tunnels and adjacent canisters, and vertically bounded by the ground surface located 500 m above the deposition tunnel and the surface located 500 m below the bottom of the borehole. Using a commercial finite element analysis code and detailed realistic finite element models of repository components, transient heat transfer analyses are carried out for up to 1000 yr after deposition of the canister into the repository. Time-dependent temperature curves at selected positions are obtained for each geometric model. Various temperature distribution changes of material regions in geometric models are also obtained.

Personal CO&lt;SUB&gt;2&lt;/SUB&gt; Scrubbing Device for Use in a Disabled Submarine

In the sunken submarine, a breakdown in the power supply can disrupt the provision of fresh air and the absorption of CO2. A personal device based on a breathing mask and the soda lime canisters used in the submarine is proposed for CO2 absorption. In an unmanned experiment, a breathing simulator provided a flow of air at 8.7 L x min(-1) and a carbon dioxide output of 20.9 L x h(-1), which passed through either one or two 3.8-kg canisters of soda lime. In the manned experiment, four subjects wore the breathing mask, which was connected to two 3.8-kg canisters of soda lime placed in a bag, and remained for 24 h in a sealed hyperbaric chamber. They inspired the chamber atmosphere and expired via the canisters. In the unmanned experiment, the concentration of CO2 when a single canister was used reached 1% after 8 h, 2% after 22 h, and 2.5% after 37 h. With two canisters connected in sequence, the concentration of CO2 reached 1% after 48 h, while the pressure at the entrance to the canisters did not exceed 0.7 cm H2O. In the manned experiment, the CO2 concentration decreased over the first 12 h from its initial value of 1.3%, stabilizing during sleep at 0.75%. The personal carbon dioxide absorption device lowered the ambient CO2 level over a period of 24 h, and could maintain this level for a further 24 h. Keeping CO2 at a low level has an advantage over the peaks of 3% obtained with absorbent LiOH curtains, where elevated pressure and increased P(CO2) may have an adverse effect on the survivors. Some of the crew can remain active without using the device, while the others do the job of clearing the carbon dioxide for the whole crew.

Comparative Analysis of Results From Deterministic Calculations of the Release of Radioactivity From Geological Disposal of Spent Fuel in Crystalline Rocks

AbstractThis paper presents results from deterministic calculations of radionuclide migration in a deep geological environment. The concept assumes single canister with spent nuclear fuel situated in bentonite (near-field) and surrounded by crystalline host rock (far-field). The results are presented in the form of release rates from the near-field and far-field, which contains also a part of advective release from the system of two single fractures. Additionally, radiological risk is evaluated in the form of dose rates for a water drinking scenario for an exposed population group. The analyses have been done by using the methodologies and computer codes used at the Institute for Energy EC-JRC in the Netherlands and the Mining Institute KSC RAS in Russia.

Temperatures in Soda Lime During Degradation of Desflurane, Isoflurane, and Sevoflurane by Desiccated Soda Lime

Rarely, fire and patient injury result from the degradation of sevoflurane by desiccated Baralyme. The present investigation sought to determine whether high temperatures also arose with sevoflurane use in the presence of desiccated soda lime. We desiccated soda lime by directing a 10 L/min flow of oxygen through fresh absorbent. Using 1140 +/- 30 g (mean +/- sd) of this desiccated absorbent, we filled a single standard absorber canister placed in a standard anesthetic circuit to which we directed a 6 L/min flow of oxygen containing 1.5 minimum alveolar concentration (MAC) desflurane or sevoflurane, or 3.0 MAC desflurane, isoflurane, or sevoflurane (with and without concurrent delivery of 200 mL/min carbon dioxide). In an additional test, 2 canisters (rather than a single canister) containing desiccated absorbent were used and 3.0 MAC sevoflurane was applied. A 3-L reservoir bag served as a surrogate lung, and we ventilated this lung with a minute ventilation of 10 L/min. With desflurane at 1.5 MAC or 3.0 MAC or isoflurane at 3.0 MAC temperatures increased in 20 to 40 min to a peak of 30 degrees C to 45 degrees C and then declined. With 1.5 or 3.0 MAC sevoflurane, temperatures increased to approximately 90 degrees C, after which temperatures declined. Concurrent delivery of carbon dioxide and sevoflurane did not increase the peak temperatures reached. The use of 2 canisters increased the duration but not the peak of increased temperature reached with 3.0 MAC sevoflurane. No fires resulted from degradation of any anesthetic.

Design and characteristics of an MDI counter device

RATIONALE: The need for an MDI counter device has been identified by manufacturers, regulatory and patient groups. We identified concerns of MDI users and described the attributes of a newly developed MDI Counter. METHODS: Questionnaire data was collected from patients with previous MDI experiences. Counter reliability data were generated from in vitro testing conducted on an MDI with counter. RESULTS: In a survey of 237 Asthma and COPD patients, 63% felt anxious not knowing the number of doses remaining in their MDI. 41% said they sometimes waited until the MDI was completely empty and about 20% said they could never tell when the MDI was out of medication. To reliably inform patients of remaining doses, an MDI with counter has been developed. This counter is a numerical design, counting down to zero. This counter has been designed to continue to display 000 when the product has delivered the labeled number of actuations, but will allow continued use by not locking out additional actuations. This counter is permanently attached to the canister ensuring that the count is associated with a single canister. In vitro testing showed count accuracy in excess of 99%. Actuation forces for MDI with counter are similar to MDI without counter (both in the range 33-40N). Inhaler size and weight are similar to standard product without a counter such that patients routinely using MDIs will experience no handling differences. CONCLUSIONS: The design and function of this MDI counter addresses patients' concerns and regulatory standards for these types of devices.

A review of the USEPA's single breath canister (SBC) method for exhaled volatile organic biomarkers

Exhaled alveolar breath can provide a great deal of information about an individual's health and previous exposure to potentially harmful xenobiotic materials. Because breath can be obtained non-invasively and its constituents directly reflect concentrations in the blood, its use has many potential applications in the field of biomarker research. This paper reviews the utility and application of the single breath canister (SBC) method of alveolar breath collection and analysis first developed by the US Environmental Protection Agency (USEPA) in the 1990s. This review covers the development of the SBC technique in the laboratory and its application in a range of field studies. Together these studies specifically show how the SBC method (and exhaled breath analysis in general) can be used to clearly demonstrate recent exposure to volatile organic compounds, to link particular activities to specific exposures, to determine compoundspecific uptake and elimination kinetics, and to assess the relative importance of various routes of exposure (i.e. dermal, ingestion, inhalation) in multipathway scenarios. Specific investigations covered in this overview include an assessment of exposures related to the residential use of contaminated groundwater, exposures to gasoline and fuel additives at self-service gas stations, swimmers' exposures to trihalomethanes, and occupational exposures to jet fuel.

Criticality Characteristics of Mixtures of Plutonium, Silicon Dioxide, Nevada Tuff, and Water

The parameters that determine when critical mixtures of 239Pu, SiO2, and water and mixtures of 239Pu, Nevada tuff, and water are capable of sustaining an increasing neutron chain reaction as may be caused by a positive void coefficient at constant temperature are established. A single canister is considered that is loaded with up to 75 kg of 239Pu. A survey of critical spherical mixtures of plutonium, SiO2, tuff, and water at constant temperature is created and these results are examined to determine the mixtures that might be autocatalytic. Regions of criticality instability are identified that have the possibility of autocatalytic power behavior. A positive void coefficient is possible for a very limited range of wet systems.

A ground-based study for a shuttle bric experiment on gravity effects on gene expression

A BRIC (Biological Research In a Canister) experiment to investigate the effects of reduced gravity at the molecular level using Arabidopsis has been initiated. In preparation for a space flight experiment, a series of ground-based studies were conducted. Results from these studies indicate that: 1) up to 20,000 seeds can be germinated on a 100 mm diameter Petri plate, 2) nylon membrane is the best surface for recovery of plant material after freezing, 3) depending on the age of the seedlings at the time of freezing, 20 to 40 g of tissue can be obtained from Petri plates that fit in a single canister; 4) tissue from one canister yields adequate amounts of RNA to perform differential display to isolate gravity-regulated genes. Our results indicate that the proposed BRIC experiment is feasible and can provide valuable information on the possible effects of microgravity on gene regulation.

Calculation of the radiation transport in rock salt using Monte Carlo methods

To improve the final concept for a high-level radioactive waste (HAW) disposal in geological salt formations, plans have been developed in Germany for a full scale testing of an underground repository. As a main part of this so-called HAW project, the testwise emplacement of 30 vitrified highly radioactive canisters was planned in test galleries at the 800 m level of the Asse salt mine near Braunschweig, Germany. An attempt should be made to correlate the changes induced to the salt with the amount of energy deposited there. This paper provides absorbed dose rate and photon fluence rate distributions in rock salt around these highly radioactive canisters, containing the radionuclides 137Cs and 90Sr, and around a single canister containing radioactive material of a lower activity level (INHAW experiment). The data given were calculated using a Monte Carlo method simulating photon transport in complex geometries of differently composed materials. The aim of these calculations was to enable determination of the dose absorbed in any arbitrary sample of salt 1 m around the canisters to be further examined in the future with sufficient reliability for safety considerations. The geometry of the test arrangement, the materials involved, the calculational method and selected results are shown.

Fast Model for Calculating Steady State Release of Radionuclides from the Near Field

ABSTRACTA model has been developed which describes the steady state transport of dissolving species of radionuclides from a single canister in a repository for spent nuclear fuel into the passing water in fractures in the surrounding rock. The steady state transport of nuclides is described by a network of transport resistances, coupled together in the same way as an electrical circuit network. With the model a number of calculations are done for various sets of fracture geometry data. The calculations indicate that the resistance network model gives results comparable to those of a complex 3-dimensional numerical model. The present model is very simple and fast.

Radioactive waste disposal

The Swedish concept of deep underground nuclear waste disposal is described. This system is based on multiple barriers isolating the fuel from the biosphere. The barriers are: the spent fuel material, which has a very low solubility; the copper canister with its very high corrosion resistance in the actual environment; the buffer material, which limits the amount of groundwater that can be in contact with the canister; and the bedrock, which has a low hydraulic conductivity and a high capacity for sorption of radionuclides. A number of scenarios have been studied in order to assess the effects of certain improbable events of conditions, such as early damage to a single canister, oxidising conditions throughout the whole geosphere and transport by colloids and complexing agents. The analysis shows that the calculated resulting doses to man are negligibly small compared with radioprotection standards and natural radiation levels

Cleaning, Storage, and Repeated Use of Twin Coil Dialyzing Units

Hemodialysis for chronic renal failure is an expensive means of prolonging life.1With twin coil dialyzers the cost per dialysis is less if the coil and arterial set is reused. In the Madison, Wis, and Portland, Ore, Veterans Administration Hospital dialysis units, we have reduced the cost of expendable items to about $12 per dialysis by cleaning and reusing coils. The method is simple, safe, and does not alter the effectiveness of the coil. Methods.— We use either the Travenol 100-liter tank single canister model or the Travenol recirculating single pass 120-liter tank unit (RSP), together with the Travenol 190 twin coil. Cleaning and Storage.— After dialysis, the coil is removed and placed on its side in the canister of the RSP or the half-drained 100-liter tank. One liter of sterile normal sodium chloride solution containing 10 mg heparin sodium displaces 2 units of blood into bottles containing anticoagulant