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.     

Thermal analysis of a storage cask for 24 spent PWR fuel assemblies

Abstract

The purpose of this paper is to perform a thermal analysis of a spent fuel storage cask in order to predict the maximum concrete and fuel cladding temperatures. Thermal analyses have been carried out for a storage cask under normal, off-normal and accident conditions. The environmental temperature is assumed to be 27°C under the normal condition. The off-normal condition has an environmental temperature of 40°C. An additional off-normal condition is considered as a partial blockage of the air inlet ducts. Four of the eight inlet ducts are assumed to be completely blocked. The accident condition is defined as a 100% blockage of air inlet ducts. The storage cask is designed to store 24 PWR spent fuel assemblies with a burn-up of 55,000 MWD/MTU and a cooling time of 7 years. The decay heat load from the 24 PWR assemblies is 25.2 kW. Thermal analyses of the ventilation system have been carried out for the determination of the optimum duct size and shape. The finite-volume computational fluid dynamics code FLUENT was used for the thermal analysis. From the results of the analysis, the maximum temperatures of the fuel rod and concrete overpack were lower than the allowable values under the normal, off-normal and accident conditions.     

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.     

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.     

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.     

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.     

New generation standard nuclear material container

Abstract

Nuclear Filter Technology (NucFil) is working with the Los Alamos National Laboratory (LANL) to design a nuclear material storage container that complies fully with the requirements of DOE M 441·1-1. LANL provided NucFil with a specification that outlines requirements to comply with the manual, as well as to satisfy specific needs of their own. NucFil has taken this specification and designed a container known as the new generation standard nuclear material container (NG SNMC). The premise of the design is a simple, robust container that is easy to use. The sealing mechanism is a single large cross-section, low durometer o-ring. The large cross-section provides a tight seal that has enough elastic rebound to compensate for any distortion of the sealing faces after a potential drop. The low durometer keeps the force required to open and close the container low. Once compressed, the seal is kept in place by a bayonet style closure that is locked in place by a positive mechanical engagement. The components of the container exposed to the load are manufactured of corrosion resistant 316L stainless steel. The container has a filter made of a heat resistant ceramic fibre to retain particles after a fire, and a water resistant membrane to keep moisture out of the container. Pewter shielding can be attached and is latched in place. These features are present in all seven sizes of the NG SNMCs, including 1, 3, 5, 8 and 12 quart and 5 and 10 gallon.     

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.