Normal Conditions Of Transport Research Articles

Perna perna mussel reference material: short term stability assessment

Instrumental neutron activation analysis was used at a 2-month long isochronous short term stability test performed on a Perna perna mussel candidate reference material. The assessment of the analysis of variance test, as well as, the normalized results to the control temperature showed no systematic changes in the concentration of Ag, As, Br, Co, Cr, Cs, Fe, Eu, La, Na, Rb, Se, Sc, Th and Zn during the test period. The result showed that the candidate reference material may be transported under normal transport conditions without significant changes in composition for the determined elements.

Vulnerabilities of legacy fuel casks when evaluated using modern structural analysis tools

AbstractCylindrical fuel casks often have impact limiters surrounding the ends of the cask shaft in a typical 'dumbbell' arrangement. The primary purpose of these impact limiters is to absorb energy to reduce loads on the cask structure during impacts associated with a severe accident. Impact limiters are also credited in many packages with protecting closure seals and reducing peak temperatures during fire events. For this credit to be taken in safety analyses, the impact limiter attachment system must be shown to retain the impact limiter following normal conditions of transport (NCT) and hypothetical accident conditions (HAC) impacts. Large casks are often certified by analysis only because of the cost associated with testing. Therefore, some cask impact limiter attachment systems have not been tested in real impacts. A recent structural analysis of the T-3 spent fuel containment cask found problems with the design of the impact limiter attachment system. Assumptions in the original safety analysis for...

Mechanical characteristics of fuel rod claddings in transport conditions

AbstractA synthesis on the mechanical characteristics of unirradiated and irradiated fuel rod claddings was performed by the French Institut de Radioprotection et de Surete Nucleaire (IRSN) in order to have reference data for the assessment of the safety demonstrations in normal and accident conditions of transport required by the procedure of package licensing. Indeed, the transport conditions correspond to a range of cladding temperatures (200–550°C) which is only partly covered by the data acquired within the framework of the safety demonstration relative to the reactor normal operating conditions, especially beyond 400°C. This work concerned Zircaloy-4 cladding material (Zry-4) and M5TM. Data about mechanical properties (elastic and ductile properties, creep behaviour), oxidation (in reactor and under air during transport), hydrides and fracture toughness have been collected and synthesised. The laws presented in the document can be used to obtain orders of magnitude of oxide layer thickness, hydrogen...

Evaluation and verification of a structural safety analysis for a type B transport package for a radioactive waste drum

We conducted and verified the structural safety analyses for a type B transport package for a radioactive waste drum. The type B package is used to transport one high-level radioactive waste drum from a waste facility to a temporary site in a nuclear power plant. It is important that the structural integrity of a type B transport package should be maintained under normal transport conditions such as the free drop test, the stacking test and the penetration test, and accident conditions of transport such as the 9 m height free drop test and the puncture test. Based on the ASME Boiler and Pressure Vessel Code, Section III, Division 3 we evaluated the structural safety integrity of the type B package for a radioactive waste drum using finite element analysis. For the stacking test condition the maximum stress is a very low value when compared with the stress limits. The impact of the penetration bar on the overpack does not affect the containment part. For the free drop test condition and the puncture test condition the local stresses appear at the impact part and the containment part connected with the inner structure. The maximum stresses for all of the conditions are lower than the stress limits, so the structural integrity of the type B package for a radioactive waste drum was maintained. Also, the structural safety analyses were verified by using the data acquired from the 9 m drop and the puncture tests of the real model. The analytic accelerations of the 9 m drop test are similar to the test results. For the puncture test condition the analytic result is conservative when compared to the test. The analysis for the structural safety of the type B package reveals conservative results and it is proved that its structural integrity is maintained under normal and accident conditions of transport.

The Effect of a Free Drop Impact on the Bolted Joint of the Radioactive Transport Package

In this study the effect of a free drop impact on the bolted joint of the transport package of radioactive material was studied under various directions. A drop test of a type A or a type IP transport package of radioactive material should be conducted under normal transport conditions. After a drop test the radioactive content of the transport package should not be loss or dispersal. A bolt tension during a drop impact under various directions was measured using a force sensor. And the torque to loosen a bolt was measured after the tests. A bolt tension measured by the tests was compared with the result of a finite element analysis. The effect of the drop direction was examined. The vertical drop directions shows larger bolt tension than horizontal drop. For the torque to loosen a bolt, a horizontal drop condition shows larger value than a vertical drop direction.

Measurement techniques and preliminary results of drop tests with full scale spent fuel transport and storage casks

The experimental testing and quantitative stress analysis of new cask designs becomes more and more important with increasing size of casks and their impact limiters, in order to assess the safety margins as well as for calculation validation reasons. Full scale drop testing of spent fuel transport and storage casks is performed by the Federal Institute for Materials Research and Testing within the type B package approval procedure and for safety demonstration reasons respectively. In drop tests for demonstrating ability of a package to withstand normal and accident conditions of transport, the instrumentation of a specimen is an important tool to evaluate its mechanical behaviour during impact. Generally, the instrumentation incorporates the measurement of strains and accelerations at the package. Test results as deceleration–time and strain–time functions constitute a main basis for the validation of assumptions in the safety analysis, for the evaluation of calculations based on finite element methods and extrapolation of scale model testing on full sized package within approval design tests. Besides, all of the above mentioned instrumentation, the flatness of the sealing area and the circularity of the cask lid flange are determined by using three-dimensional coordinate measurements to evaluate the mechanical impact behaviour of the cask flange region after the drop test sequence. Indispensable are measurements concerning leak tightness of the closure lid system. Additionally, specific photogrammetric measurements are used to characterise the conditions of the closure lid system after drop test in more detail. The preparation and interpretation of the results is in progress and indicates possible correlations between the leak tightness rate and measures of the relative movement of the lid.

The relevance of IAEA tests to severe accidents in nuclear fuel cycle transport

The design and performance standards for packages used for the transport of nuclear fuel cycle materials are defined in the IAEA Regulations for the Safe Transport of Radioactive Materials, TS-R-1, in order to ensure safety under both normal and accident conditions of transport. The underlying philosophy is that safety is vested principally in the package and the design and performance criteria are related to the potential hazard. Type B packages are high-duty packages which are used for the transport of the more radioactive materials, notably spent fuel and vitrified high-level waste (VHLW). Tests are specified in the IAEA regulations to ensure the integrity of these packages in potential transport accidents involving impacts, fires or immersion in water. The mechanical tests for Type B packages include drop tests onto an unyielding surface without giving rise to a significant release of radioactivity. The objects which could impact upon a package in real-life transport accidents, such as concrete roads, bridge abutments and piers, will yield to some extent and absorb some of the energy of the moving package. Impact tests onto an unyielding surface are therefore relevant to impacts onto real-life objects at much higher speeds. The thermal test specifies that Type B packages must be able to withstand a fully engulfing fire of 800°C for 30 min without significant release of radioactivity, and this has to be demonstrated, for example, by analytical studies backed up by experimental tests. The regulations also specify immersion tests for Type B packages of 15 m for 8 h without significant release of radioactivity; and in addition for spent fuel and VHLW packages, 200 m for 1 h without rupture of the containment. There is a large body of evidence to show that the current IAEA Type B test requirements are severe and cover all the situations which can be realistically envisaged in the transport of spent fuel, VHLW and other fuel cycle materials. Any proposals for more severe tests, which have little technical justification, should therefore be treated with caution since this could result in a loss of public confidence in the current regulations, and the ratcheting up of design requirements which could not be justified on quantitative safety grounds.

QUANTIFICATION OF EMBOLI BY VISUALIZATION OF AIR FILLED XYLEM VESSELS

Between harvest and vase life the cut surface of most cut flowers is exposed to air for a longer or shorter period. It was hypothesized that under normal harvest and transport conditions air only enters the cut open vessels and does not move to non-cut vessels. The vessel length distribution of chrysanthemum stems was analyzed with the latex particle method and compared to the distribution of air embolisms in 5ow/w) desiccated stems, visualized using cryo-scanning electron microscopy. It was concluded that by moderate desiccation all cut open vessels are completely air-filled and that intact vessels are not embolized.

Normal flow boundary conditions in 3D circulation models

SUMMARY The problem of enforcing normal transport conditions on 3D velocity fields is considered in the context of ‘wave equation’ finite element models. A procedure for strong enforcement of the transport constraint is given. The procedure is identical for Neumann (transport known) and Dirichlet (pressure known) problems, which are treated reversibly. All local mass and force balance relations are retained in the FEM system. A global mass conservation property is proven for the general 3D, discrete-time case. Examples demonstrate the quality of the solutions and the practicality of the approach.# 1997 John Wiley & Sons, Ltd.

Dynamic Analysis of a Container with a Single Layer of Drums Mounted on a Railroad Car Suffering Collision

Dynamic analysis has been performed with a new Type of 20' box container qualified as an industrial package Type 2 and 3 and as a Type A container. In the model for a numerical collision experiment the container was partially loaded with 21 × 1000 kg drums, arranged along three parallel rows forming a single layer. One of the aims in the container development was to achieve a system that could transport cargoes with a variable number of drums stacked in changeable configurations, while ensuring the safety of the container for dynamic forces that could arise during normal conditions of transport. This led to the design of an interchangeable tray for the drums that can easily be handled and loaded into the container, together with passive restraining devices that prevent this assembly from moving inside the container when subjected to dynamic forces. The container system is designed to withstand accelerations of up to 6g in the longitudinal direction. These can be expected during normal switchyard operations at collision speeds of about 13 km.h−1. In the dynamic analysis, initially the collision speed is assumed to be low, but then it is gradually increased until damaging forces are observed. For moderate collision speeds <10 km.h−1) the shock absorbers of the railroad and ram car remain fully functional. However, at speeds exceeding 10 to 11 km.h−1 the shock absorbers reach their full travel capacity, and a true impact occurs. At this point, the forces on the walls of the container, caused by the inertia of the cargo, grow rapidly with the speed of the collision, depending on how well the tray support system functions in its shock-absorbing capacity. One result of the calculations is that stiff support systems are not capable of absorbing the impact forces once the critical velocity of 10 km.h−1 is exceeded, since the forces quickly grow beyond even the design strength of a new 20' box container of 500 kN. In comparison the design strength of a today's IP 2/IP 3 container is only approx. 80 kN. In the numerical experiments, it was observed that a soft cushioning support tray system like the one developed by CORROBESCH/STM has excellent shock absorbing characteristics. By contrast, a rigid support system, or worse, no support system at all, is likely to produce impact forces at normal conditions of transport capable of endangering the container walls.

Testing of Elastomer Seals using Small-Size Rigs

This paper looks at the use of small size seal leakage test rigs to demonstrate the compliance of full size container seals against the IAEA Transport Regulation's limits for activity release for normal transport and accident conditions. The detailed requirements of the regulations are discussed and it is concluded that an appropriate test programme to meet these requirements, using only small size test rigs, can normally be set up and carried out on a relatively short time scale. It is important that any small test rigs should be designed to represent the relevant features of the seal arrangement and the overall test programme should cover all of the conditions, specified by the regulations, for the type, classification and contents of the container under consideration. The parameters of elastomer O-rings, which affect their sealing ability, are considered and those which are amenable to small scale testing or have to be modelled at full size are identified. Generally, the seals used in leakage tests have to be modelled with a full size cross-section but can have a reduced peripheral length.

Urine-based diagnostic technologies

The worldwide dissemination of infectious agents has created a demand for simple diagnostic tests. Urine-based testing makes use of non-invasive collection of specimens, and there is no need for expensive facilities and equipment, or for highly trained personnel. As urine antibodies retain activity under normal conditions of transport and storage, such tests appear to have widespread application. Urine-based antibody tests have also indicated a compartmentalized antibody response to HIV-1 infection. Urine studies suggest that antibodies to the products of endogenous viral genes may be involved in the pathogenesis of chronic diseases of suspected viral etiology.

Testing of the Sealing Arrangements for the Nirex Re-Usable Shielded Transport Containers

AbstractAs part of its responsibility for the development of a deep repository for intermediate and low level radioactive waste, UK Nirex Ltd is developing a range of Type B re-usable shielded transport containers (RSTCs). A testing programme has been carried out on two alternative concepts for the RSTC sealing arrangements over the temperature range −40°C to 200°C. For each sealing system, a test rig was developed to measure the performance under simulated normal and accident conditions of transport. The elastomer O-rings used for some of the tests had been irradiated to the maximum dose they might receive in normal transport. The performance of both sealing systems was good and it is concluded that either concept would meet the specified leakage criteria over the full temperature range under both normal and accident conditions of transport. However, further testing is required to confirm the performance of Concept N under accident conditions.

Twenty Years of Experience in Spent Fuel Shipment from German Nuclear Power Plants—A View of the Competent Authority

A survey of the transport of spent fuel in and from Germany during the last 20 years is presented. The spent fuel is now transported from the German nuclear power facilities to the reprocessing plants in France and the United Kingdom. In the past, there were also shipments to the former reprocessing plant WAK Karlsruhe (Germany), to the long-term storage facility CLAB (Sweden) and also from the former German Democratic Republic to the USSR. The transport of the spent fuel is carried out in specially built flasks requiring an extensive quality assurance programme. Due to the heavy weight of these packages, the shipments are mostly carried out by rail, but also by road and sea. An overview is given of the following matters: (i) quantities of spent fuel transport, (ii) organisation of transport, (iii) licensing matters, and (iv) reported incidents. In addition, an analysis is included of the radiation exposure for normal conditions of transport, especially of the transport workers. Difficulties and hindrances during transport are also reported.

Transport Packages for Radioactive Materials: Potential Simplifications to Regulatory Requirements

AbstractSimplified packaging requirements for radioactive materials are proposed. The range of Industrial Packages for Low Specific Activity materials and Surface Contaminated Objects can be reduced, simplifying the choice of package and providing clearer aims for consignors and package designers. Alternative approaches, such as the use of other forms of approval, are retained, enabling ISO Freight Containers and UN-approved drums to be specified. In line with these simplifications, proposals for testing requirements are described. These retain the existing safety standards while permitting a broader range of package design options. The range of package groups proposed is Excepted, Industrial, Type A, Type B and Type C. The sub-groups of Industrial Package are abandoned. The tests for Normal Conditions of Transport are amended to reflect conditions likely to be experienced. Tests representing accident conditions are not changed in these proposals. The main change suggested is to restrict impact tests repr...

An Approach to Assessing the Impacts of Incident‐Free Transportation of Radioactive Materials: I. Air Transportation

Annual radiation doses and risks to passengers and crew are calculated for shipments of radioactive materials in passenger aircraft under accident‐free and incident‐free conditions (i.e., under normal transportation conditions). The 1982 database developed by Sandia National Laboratories is used, and calculations are made using RADTRAN 4.0. This paper is one of two papers estimating radiological risk associated with incident‐free transportation of radioactive materials.

An Approach to Assessing the Impacts of Incident‐Free Transportation of Radioactive Materials: II. Highway Transportation

Annual radiation doses and risks to the public living near, and traveling on, public highways, and occupational doses are calculated for highway shipments of radioactive materials under accident‐free and incident‐free conditions (i.e., under normal transportation conditions). The database developed by Sandia National Laboratories is used, and calculations are made using RADTRAN 4.0. This report is one of two reports estimating radiological risk associated with transportation of radioactive materials.

Effect of storage conditions on the stability of vitamin C in various fruits and vegetables produced and consumed in Quebec

Nearly 90% of vitamin C in the human diet is obtained from fruits and vegetables as ascorbic and dehydroascorbic acids. However, these compounds are sensitive to light and oxygen and may decompose under normal transport and storage conditions, resulting in reduction of the nutritional value of the foodstuffs. In this work, the effect of various commercial and domestic storage conditions (3, 8, 23°C with or without light) on vitamin C contents of some fruits and vegetables produced in Quebec was studied. In general, degradation of vitamin C is a function of time. In some foodstuffs, however, the onset of degradation is delayed during the first few days during which the vitamin content actually increases as a result of continuing endogenous metabolism.

Large Package Tests for Normal Conditions of Transport

The IAEA Regulations (1985) for the Safe Transport of Radioactive Material specify requirements for packagings and packages (Section 5). These include tests for normal conditions of transport (Paras 619–625) and accident conditions for packages containing larger quantities of activity (Paras 626–633). The tests for normal conditions include drop tests from heights which vary with the package mass (Para 622). The ‘Explanatory Material’ (1987) describes these drop-tests as ‘a falloff the platform of a vehicle’ after which ‘packages would continue the journey’. There is clear implication that any damage which obviously degrades important functions of the packaging system results from ‘accident’ damage rather than ‘normal conditions of transport’. The important functions include containment, criticality control, shielding, impact protection and fire protection. Large packages, such as ISO containers, may exceed 6 m in length and when subject to a corner drop of 1 m or less, the centre of gravity will fall more than 3 m. The secondary impact will be much more severe than the initial impact. Neither the corner drop nor the secondary impact simulate normal conditions of transport. An alternative specification for normal condition drop testing of large containers is proposed, avoiding the more severe damage resulting from secondary impacts.

Apical membrane Na+/H+ exchange in Necturus gallbladder epithelium. Its dependence on extracellular and intracellular pH and on external Na+ concentration.

Intracellular microelectrode techniques and extracellular pH measurements were used to study the dependence of apical Na+/H+ exchange on mucosal and intracellular pH and on mucosal solution Na+ concentration ([Na+]o). When mucosal solution pH (pHo) was decreased in gallbladders bathed in Na(+)-containing solutions, aNai fell. The effect of pHo is consistent with titration of a single site with an apparent pK of 6.29. In Na(+)-depleted tissues, increasing [Na+]o from 0 to values ranging from 2.5 to 110 mM increased aNai; the relationship was well described by Michaelis-Menten kinetics. The apparent Km was 15 mM at pHo 7.5 and increased to 134 mM at pHo 6.5, without change in Vmax. In Na(+)-depleted gallbladders, elevating [Na+]o from 0 to 25 mM increased aNai and pHi and caused acidification of a poorly buffered mucosal solution upon stopping the superfusion; lowering pHo inhibited both apical Na+ entry and mucosal solution acidification. Both effects can be ascribed to titration of a single site; the apparent pK's were 7.2 and 7.4, respectively. Diethylpyrocarbonate (DEPC), a histidine-specific reagent, reduced mucosal acidification by 58 +/- 4 or 39 +/- 6% when exposure to the drug was at pHo 7.5 or 6.5, respectively. Amiloride (1 mM) did not protect against the DEPC inhibition, but reduced both apical Na+ entry and mucosal acidification by 63 +/- 5 and 65 +/- 9%, respectively. In the Na(+)-depleted tissues mean pHi was 6.7. Cells were alkalinized by exposure to mucosal solutions containing high concentrations of nicotine or methylamine. Estimates of apical Na+ entry at varying pHi, upon increasing [Na+]o from 0 to 25 mM, indicate that Na+/H+ exchange is active at pHi 7.4. Intracellular H+ stimulated apical Na+ entry by titration of more than one site (apparent pK 7.1, Hill coefficient 1.7). The results suggest that external Na+ and H+ interact with one site of the Na+/H+ exchanger and that cytoplasmic H+ acts on at least two sites. The external titratable group seems to be an imidazolium, which is apparently different from the amiloride-binding site. The dependence of Na+ entry on pHi supports the notion that the Na+/H+ exchanger is operational under normal transport conditions.