Safe transport of radioactive material in Brazil

Abstract

The objectives of this article are to briefly present an updated review of the regulatory framework and activities related to the transport of radioactive material in Brazil, to provide an analysis of the appraisal service performed by the International Atomic Energy Agency (IAEA) in 2002 and to identify questions that require action plans from the Brazilian Nuclear Energy Commission (CNEN), including those actions which will involve neighbouring countries regulatory authorities.     

Threat analysis for transport of radioactive material using morphological analysis

Abstract

The Swedish Defence Research Agency (FOI) was commissioned by the Swedish Nuclear Power Inspectorate to carry out a pilot study which would serve as the basis for a revised set of regulations regarding physical protection and administrative routines for the transport of radioactive material. The pilot study was to develop a prototype model by which a comprehensive threat analysis could be carried out. The study employed computer aided morphological analysis, which is a flexible, non-quantified modelling method developed at FOI during the 1990s. The paper will present the methodological foundations of morphological analysis and present the prototype models involving general threat scenarios, transport situations, antagonists and strategic measures.     

Challenges in the renewal of the Swedish sea transport system

Abstract

Since 1985, SKB has successfully operated a sea transport system for transport of spent nuclear fuel and radioactive waste to the intermediate storage facility, Clab and the final repository, SFR, in Sweden. The main components in the system are the ship M/S Sigyn, transport casks for spent fuel and core components, IP2 containers and terminal vehicles.     

Radiological impact of transport of radioactive material in UK by road and rail

Abstract

A survey has been carried out on the transport of radioactive materials by road and rail in the UK by the Health Protection Agency's Radiation Protection Division. This survey, carried out in 2004, is the latest in a series of periodic studies on the transport of radioactive materials by all modes of transport. Questionnaires were sent to hospital departments, radionuclide manufacturers, suppliers, and carriers, and to the nuclear and other industries, in order to obtain data on shipments of radioactive materials. Visits were made to hospitals, suppliers, carriers and some railway premises in order to observe working practices and radiological surveys were made while packages were handled. Assessments of individual doses to workers and members of the public were made, and occupational dosimetry data were also obtained. It was found that ～500 000 package movements take place by road annually in the UK, with ～4000 package movements annually by rail. Radiation doses to most transport workers are low, with an average dose of 0·6 mSv to general workers transporting medical and industrial sources. Doses to individual members of the public are very low, with average annual doses of less than 0·02 mSv.     

Comparison of collective dose in India and USA owing to transport of radioactive material by road

Abstract

This paper estimates probable collective doses owing to transport of radioactive material by road mode in India and the USA for an identical hypothetical case under respective transport conditions for the two countries, using the INTERTRAN2 computer code. The differences observed in the transport conditions in the two countries are reflected in the DNORM input parameters for the incident free transport conditions of transport and the accident rates. Owing to differences in the parameter values, it is found that the estimated probable collective dose values owing to transport of radioactive material by road mode for India are much higher than those for USA. Sensitive parameters are identified which contribute maximum to the estimated probable collective dose.     

Some views on 2 year review/revision cycle of IAEA regulations for safe transport of radioactive material

Abstract

In the past the International Atomic Energy Agency (IAEA) transport regulations have normally been reviewed or revised within a 10 year cycle to support changes in transport operations arising from administrative and technical developments and new knowledge in fields concerning the transport of radioactive material. Beginning in 2003, consistent with the time schedules of the United Nations (UN) Sub-Committee of Experts on the Transport of Dangerous Goods and of the relevant international modal organisations, a regular 2 year review of the IAEA transport regulations was established, with a view to issuing a revised or amended edition as necessary. This paper describes the process of the review/revision itself, the transfer to the regulations of the UN and the modal organisations as well as implementation within the legislation of the member states. The advantages and disadvantages of the more frequent process are analysed: on the one hand harmonisation with the UN and the modal organisations, on the other hand a possible lack of sufficient stability in the regulations themselves. The need for the 'Schedules of requirements for the transport of specified types of radioactive material consignment', which are an integral part of the IAEA transport regulations TS-R-1 but which from 1 January 2005 are no longer a part of the international modal regulations, is discussed.     

Some aspects on harmonization between IAEA 'Regulations for the safe transport of radioactive material' and UN 'Recommendations on the transport of dangerous goods'

Abstract

Since 2001, the IAEA 'Regulations for the safe transport of radioactive material' are directly implemented into the UN 'Recommendations on the transport of dangerous goods', Model Regulations (the so called 'Orange Book') as class 7: radioactive material. At the same time, consistent with the time schedule of the United Nations Sub-Committee of Experts on the Transport of Dangerous Goods and the relevant international modal organisations, a regular review process of the IAEA Transport Regulations intended to issue a revised or amended edition, as necessary, every two years, was established. The last published version, the fourteenth revised edition of the 'Orange Book', includes the IAEA Transport Regulations, 2005 edition. However, the IAEA had decided not to publish a 2007 edition of the Transport Regulations, and as a consequence, did not recommend to the UN to implement the changes which had been adopted in the IAEA review cycle 2004–2005. In the last two years, further efforts have been made for better harmonisation between both documents. The harmonisation and assimilation with the UN Model Regulations concerning the transport of all nine classes of dangerous goods brings the class 7 'radioactive material' in line with the other classes for a worldwide implementation into the national and international modal regulations. The paper will discuss the benefits as well as some problems of this harmonisation process. The option to publish the 2009 edition of the IAEA Transport Regulations with the changes from the review revision cycle 2004–2005 and the harmonisation changes with the UN is considered to be important to keep the leading role of the IAEA in the further development of all aspects concerning the safe transport of radioactive material based on their competence in radiation protection.     

Characterising polyurethane foam as impact absorber in transport packages

Abstract

Transport and storage packages used for the safe transport of radioactive materials are required to satisfy IAEA regulations. One key design requirement for a radioactive material transport package is that under a 9 m regulatory drop test, containment functions are maintained. For certain payload types, such as fuel assemblies, impact loads on the payloads may need to be controlled in order to maintain spacing and confinement. To achieve all of this, detailed and accurate characterisation of the impact absorbing material is important in order to design an effective shock absorber. Polyurethane foam is an excellent energy absorbing material because it has a relatively high specific strength, a large compressive deformation, much of this at constant force, and a predictable compressive strength characteristic. Traditionally various types of wood have been used for this purpose, however foams are a more cost effective alternative, which are readily available, and can be formed and shaped easily. Some grades may have the added advantage of providing an almost isotropic crush response, combined with significant thermal protection. The general compressive strength properties of foams and their temperature dependencies are well documented by manufacturers; however, strain rate sensitivity and stiffness variation with orientation are not readily available. Hence impact compression tests for polyurethane foams for a range of densities from 56 to 320 kg m^–3 were specified by Rolls-Royce and performed by the Health and Safety Laboratory. These tests included dynamic conditions for a range of strain rates and temperatures and a selection of orientations of the foam. Following collation of the test results, property curves were derived for the range of temperatures at which the package was expected to operate in service between –10 and +75°C. The properties for a given specification of foam will vary within a defined tolerance range, mainly due to the variables inherent during manufacture. Hence nominal static curves were derived for each foam and a number of factors were taken into account to derive the full range of foam properties: density, compressive strength, temperature and manufacturer supplied tolerance. The net result of this work was a series of force displacement plots, depicting upper and lower bounds to account for the cumulative effects of many variables. Accounting for these upper and lower performance bounds is an essential approach in justification of any modern package design. This paper describes the characterisation and mathematical modelling of polyurethane foam for use as the main impact energy absorber in a new design of package for transporting fresh fuel. The non-linear finite element (FE) code LS-DYNA was used to carry out simulation of the tests. The HONEYCOMB material model available in LS-DYNA was used to accurately predict the test measurements of the foam material. The properties derived for the foam were then used as input to the full FE model used for the licensing of the new package design. Full scale drop testing of the package demonstrated good correlation of deformations between test and FE model analysis, providing good validation evidence of the foam characterisation in the transport package.     

Development of Chinese database on safe transport of radioactive materials

Abstract

The paper introduces the newly established Chinese database, which is still in its initial stage of development, on the safe transport of radioactive materials in China. The database will collect data on several transport routes in China that presently have comparatively large transport volume. The database mainly includes data on transport management, transport incidents/accidents and road circumstances, etc. This will provide a data shared plane for departments in charge of packaging and transport and for research institutes. Areas of improvements in the future work are also mentioned at the end of the paper.     

'Design to manufacture': journey through criticality considerations for new design fissile material transport packages

Abstract

The development of new fissile material transport packages is an increasingly complex and costly business. The IAEA regulations stipulate performance requirements for the behaviour of the package under both normal and accident conditions. The principal performance drivers are: impact/structural, thermal, shielding and criticality safety. The needs of these disciplines can often compete, with refinements becoming necessary to optimise the design of the package. Maximising the payload while achieving the required levels of safety can be time consuming and expensive. Early communication with the criticality safety analysts can frequently speed up the design process. Numerous variables are significant to criticality safety, (e.g. mass, geometry and spacing of fissile material, presence of moderators, presence of fixed poisons, potential damage to package, etc.). Small changes in the design can result in big changes in the reactivity and this may lead to a very large number of scoping calculations. Increased computing power and improved code abilities can make criticality scoping calculations much more efficient. The development of software to enable a single parameterised input to analyse multiple variations of a basic model provides significant benefits in the production of the criticality analysis and to the overall design process. Criticality analysis of a specific design and of variations in that design can now be performed more quickly and efficiently. Through frequent interaction between members of the design team, a 'fluid' design can be created, and an iterative process can then optimise the package configuration. Retaining the criticality input throughout the design, development, prototype manufacture and testing ensures that the key safety principles are progressed to the manufactured package. In turn, the time and cost of the overall project in producing an acceptable package may be much reduced. The paper presents experience from a criticality viewpoint of the development of new package designs for transport of fissile materials, emphasising the benefits of the utilisation of software/computing developments in this process, with statistics illustrating the efficiencies now achievable.     

Transport of radioactive material in South Africa

Abstract

This paper aims to present an overview of the activities related to the transport of radioactive material in South Africa. In particular, the applicable legislation, the scope of authority and regulatory functions of the competent authority (CA) is discussed. The categories of radioactive materials transported and the packaging requirements for the safe transport of these radioactive materials are also described.     

Simplified GIS based methodology to quantify risk factors for alternative route evaluation for transport of radioactive materials

Abstract

The risk associated with the transport of radioactive materials can be impacted by many factors of the transport system, as well as by the area through which the materials may travel. Informed decision making requires a quantitative evaluation of pertinent information or conditions. Geographic information systems are often used to display spatial information. The authors have developed a simplified methodology that can be used to quantify the conditions that impact risk over a segment of a transport route. The methodology aggregates the impact of a condition based on the magnitude of the impacting condition and its location with respect to the transport corridor. This paper is a proof-of-concept demonstration for the methodology for the factors of the population in the vicinity of the roadway and the highway design criteria with respect to access ramps and medians. The methodology is particularly suited to a comparison of alternative routes for decision making, where an easily implemented methodology is needed to narrow down multiple alternatives to those few requiring a more detailed analysis.     

IRSN's experience feedback list for assessment of transport package design safety reports

Abstract

Since 1996, the Institute for Radiation Protection and Nuclear Safety (IRSN), the technical support organisation of the French Competent Authority for the safety of transport of radioactive materials, has recorded the list of the difficulties most frequently encountered during the assessment of the safety reports of package designs. This experience feedback list takes into account the most recent evolutions of the regulations and the latest technological knowledge. For instance the safety reports should include the analysis of the most unfavourable configurations such as the 1 m free drop onto the bar when the package is in oblique position, the 9 m drop test of a package with slapdown, the thermal dissipation under a tarpaulin or canopies, the brittle fracture analysis at –40°C. IRSN's experience feedback list for transport package designs, which is published annually, is used as a guide by applicants to improve their package design safety reports and by IRSN for their assessments. Recently, it has been integrated in the French transport applicant guide and in the European technical guide for drafting the package design safety reports.     

Early accident simulating testing of radioactive material packages in road vehicles

Abstract

Beginning as early as the 1960s, concerns were voiced as to the adequacy of the package test standards imposed by the transport regulations promulgated by the International Atomic Energy Agency. One concern that was frequently raised and has continued to the present time is that the test standards do not necessarily simulate real accidents. The purpose of the crash tests described here that were done with typical packages carried in full scale vehicles was to assess the IAEA standards, their adequacy and to suggest changes to them that might be needed. It was also hoped that the tests, which were performed in the USA and in the UK, would show to regulators, to users of the regulations and to the public that current regulations already provide a very high level of safety for real world accidents. With time, much of the original information regarding these tests and their results has been lost. The few documents that remain have been surveyed and this paper presents summaries from this survey of the tests and their results.     

Radioactive and nuclear material transport security: awareness and application of new recommendations

Abstract

Transport of radioactive and nuclear material is highly regulated and transport safety regulations have been in effect for decades. International nuclear material transport security has been governed for many years on the basis of a binding international convention, the 'Convention for the physical protection of nuclear material', and its supporting document 'The physical protection of nuclear material and nuclear facilities' INFCIRC/225, revision 4 (corrected). On the other hand, transport security guidance for the radioactive material was published in 2008 by the International Atomic Energy Agency (IAEA) as an implementing guide, 'Security in the transport of radioactive material', nuclear security series no. 9, and is just now being implemented in many countries. Experience in implementing the radioactive material transport security guidance is being gained by countries as they make decisions on which specific security provisions to require, provide training to their regulatory staff and licensees, and begin reviewing and approving transport security plans. This experience has led to the development of practical approaches that minimise impacts as the guidance is put into practice. The nuclear material transport security recommendations in INFCIRC/225 are in the process of being revised to update them to address the current threat environment and to incorporate recommendations based on the recent amendments made to the Convention. INFCIRC/225, revision 5 will be a recommendation level document in the IAEA nuclear security series of documents. The interface between the nuclear and radioactive material transport security documents is important in order to ensure that appropriate security measures, based on both the nuclear and radioactive properties of the material being transported, are defined and implemented. This paper provides up to date information on the development of the IAEA transport security documents and presents information on implementation of the radioactive material transport security recommendations. It explains how the documents interface with each other and provides examples of how they should both be used in defining transport security requirements for shipments.     

Use of impact analysis in licensing industrial container for transporting new fuel

Abstract

The finite element (FE) method is a powerful tool for the simulation of mechanical and thermal behaviour of structures. In recent years, the explicit FE method has increasingly been used in the development of transport packages and as part of approval applications to demonstrate the performance of packages. Testing and analysis are the two methods specified in the IAEA Regulations for the Safe Transport of Radioactive Material for demonstrating the structural and thermal performance of a transport package against the requirements of the Transport Regulations. The roles of testing and analysis, and the relative prominence of the two, may vary between Competent Authorities in different countries. This can range from analysis being regarded as the primary mode of demonstration with testing as confirmatory, to testing being the primary mode of demonstration supplemented by analysis. This paper describes the use of the non-linear FE code LS-DYNA in the licensing of a new container for the transport of new nuclear fuel. The package was classified as an Industrial Package (Fissile) in accordance with the IAEA Regulations, and hence it was necessary, among other things, to demonstrate that criticality criteria were satisfied under postulated impact conditions. Physical drop tests were carried out and the results are compared with LS-DYNA computer calculations using the same FE models developed to support the design of the new container. The analyses and tests clearly demonstrate the novel use of polyurethane foam as the container main energy absorber. The FE predictions are compared for accelerations, bolt loadings and global deformations of the container. In general good correlation was obtained between predictions and tests and the differences, which did occur, particularly for accelerations, are discussed and reconciled. The paper concludes that explicit analysis codes are now so reliable for container impact calculations that minimal test work should be pursued basically for key confirmatory impact scenarios.     

Evaluation of safety of French type B package designs in severe accident environments other than regulatory

Abstract

Packages used to transport radioactive materials in France must be designed to meet the safety performance requirements when subject to the test conditions set forth in the International Atomic Energy Agency (IAEA) Regulations. During actual use, the packages may be subject to quite different accident conditions. The Institut de Radioprotection et de Sûreté Nucléaire (IRSN) has evaluated the behaviour of typical packages designed to transport spent fuel, high activity waste, fresh mixed oxide (MOX) fuel and plutonium oxide powder under realistic conditions of mechanical impact and fire. The studied designs remain safe after impact onto targets present in the real environment of transport. The energy absorption by the package ancillary equipment (transport frame) compensates for the kinetic energy increase by comparison to the energy expended during the regulatory tests. New software was developed to correctly simulate the thermal behaviour of the neutron shielding materials. The studied package designs exhibit large margins of safety concerning resistance to fire. The results obtained have been used to develop tools in support of the appraisal of emergency situations.     

Safety during whole life time: important aspect in safety assessment of sealed radioactive sources

Abstract

Many sealed sources with long halflife isotopes commonly used in industry or medicine have a long working life, up to several decades. Source integrity must be guaranteed in transport and use at any time. On the one hand, safety during the working life has to be ensured by the source design. Its strain has to be tested. On the other hand, source durability depends on the specific operating conditions. BAM as the competent authority in Germany has to assess the suitability of a source design for safe transport and use also for a longer service life for: (a) sources approved as special form radioactive material according to the regulations for the safe transport of radioactive material, (b) sources in approved devices for licence free use according to the Radiation Protection Ordinance, Para 25, and (c) sources with an extended leak test period according to Radiation Protection Ordinance, Para 66. In all these domains BAM has to assess if design and additional arrangements are qualified and guaranteed to prevent a release of radioactive content under the mechanical, chemical and physical operating conditions of the specified working life of a sealed radioactive source. As a result, limits for the duration of validity of the special form status of a source or a type approval of a device are specified and, in many cases, special additional responsibilities for users, such as periodical control and test measurements, have to be specified in approval certificates as binding conditions to satisfy the required safety standards in regulations. This paper presents BAM's experiences and shows which aspects should be considered in assessment of a lifetime limit of sealed sources.