Challenges are more than technical at PATRAM ’98

Opening the conference, Michel Livolant, director of the IPSN (Institut de Protection et de Surété Nucléaire) and president of PATRAM ’98, highlighted important issues and events in the field. These included: the sea transport of reprocessed material; the behaviour under simulated accident conditions of uranium hexafluoride; and the shipwreck of the container ship Carla off the Portuguese coast in November 1997 with French radioactive sources on board. He also referred to what he termed the recent “media event” over contamination of rail transport wagons in Germany and France. Livolant anticipated that the meeting would demonstrate that safety and economic efficiency are progressing in tandem as a result of the sharing of knowledge, continuous questioning and the rejection of a priori beliefs.

Continuing the plenary session, André-Claude Lacoste, the director of France’s nuclear safety authority, the Surété des Installations Nucléaires (DSIN), spoke about the revised system of control and implementation of transport safety in France. Since June 1997 the remit of DSIN has been extended to include all transport of radioactive material (RAM). This change in responsibilities within the public sector is intended to give a clear message that architect/engineering and safety are separate activities, and is likely to reflect a world-wide trend. After 11 months of DSIN’s new responsibility, Lacoste had been impressed by the multiplicity of the protagonists and the significance of the international aspects of RAM transport.

In a safety review, Z Domaratzki, the IAEA deputy director general for nuclear safety, pointed out that the record in the transport of RAM is an outstanding international success story, but that it was known only to a relatively small number of people. The objective is to maintain that record. In support of that aim the Secretariats of the various international organisations involved, such as the IAEA, the International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO), have been diligent in ensuring a systematic and coherent policy. The excellent performance of the regulations is not just a matter of good luck. It is the consequence of several fundamental features, namely:

• Requirements based on consideration of mechanical and thermal loads during accidents.

• Packages being designed with defence in depth (the generally high value of the payload facilitates this approach).

• Established and approved quality assurance programmes for the design, fabrication and use of packages.

• Strong regulatory oversight.

Domaratzki pointed out that usually the public only hears about RAM transport when those opposing certain shipments raise what they term ‘concerns’ which then become the subject of media attention. Domaratzki sited two examples:

• The sinking of the cargo ship Mont Louis off the Belgian coast in 1984 with 30 cylinders of uranium hexafluoride on board was in the daily news in many countries, even though there was no significant radiological release or exposure.

• A derailment of a train with flasks carrying spent fuel was announced as a near catastrophe although the rail car did not even overturn much less cause damage to the flasks.

Randal Scott, associate deputy assistant secretary for nuclear materials and facility stabilisation at the US Department of Energy (DOE), drew attention to what he termed the environmental legacy of the cold war. He argued that any problems in the civil nuclear industry are minute in comparison and quoted from a seminar held in December 1997 at the Royal Norwegian Embassy in Washington DC: “... the problems are so severe, the technical solutions so costly and the transborder consequences of accidents or continued malpractice so frightening, that broad-based international co-operation is necessary to deal with them in an adequate and responsible fashion. The nuclear safety problems in Russia are a most prominent case in point. In this case, unilateral safety remains an inherent impossibility ...”

Scott described the cold war legacy in the USA and in the Russian Federation. In the USA the majority of the problems exist at DOE sites; approximately 5000 surplus facilities had been identified by the end of 1996. The extent of the threat to the world’s environment of the Russian legacy is just beginning to be recognised.

The most significant Russian environmental legacies include:

• Ten nuclear reactors without spent nuclear fuel and seven containing nuclear fuel with a total inventory of about 130 000 Ci (4810 TBq) placed in the Novaya Zemlya Fjords and the Kara Sea.

• ~ 21 000 spent nuclear fuel assemblies from Russian Ministry of Defence Naval operations temporarily placed in concrete tanks in Zapadnaya Litsa.

• ~ 7500 spent nuclear fuel assemblies from the Murmansk Shipping Company temporarily placed aboard three floating service vessels.

• ~ 15 000 Ci (555 TBq) of low- and inter-mediate-level solid radwaste dumped into the Kara and Barents Seas.

• ~ 70 submarines now awaiting dismantling in the Kola region, 52 of which are still fuelled.

Given these hazards, the task of achieving world environmental security is large and complex, requiring agreements amongst many nuclear nations, long-range planning, technical talent and massive resources. Scott gave an insight into the international initiatives which had been started following the establishment in 1995 of the Contact Expert Group for International Radwaste Projects, requiring the packaging and movement of large quantities of RAM over long distances, possibly in severe weather, with all the operations conducted safely.

Contributions from industry featured in the final part of the plenary session. Koichi Ikeda of Chubu Electric Power said that as Japan does not have plentiful domestic energy resources, it is establishing its own nuclear fuel cycle. He described the experience of transporting RAM between Japan and Europe as excellent, with Japan being in the forefront of developments. Following the IMO establishing the INF Code [defined later in “Sea Transport” section], Japan was the first country to complete a ship conforming to the code to transport spent fuel. That ship, shown on following page, was the 3000 DWT Rokuei-Maru, completed in 1996, whose task it is to transport spent fuel to the Rokkasho reprocessing plant. Ikeda said that the RAM transport knowledge gained would be especially useful for Asian countries where the development of nuclear power is expected to make rapid progress.

Jean-Louis Ricaud, the Director General of Transnucléaire, spoke of the political dimension which applies to the reporting of minor transport incidents and to organised demonstrations such as at Gorleben. This is a consequence of public ignorance of the nature of the risks involved. The precautions taken by the nuclear industry are much superior to those used for the transport of other dangerous goods. Ricaud pointed to the trend for the nuclear industry to become international. Since RAM transport is an integral part of the nuclear industry, it also is global.

REGULATIONS & SAFETY RESPONSIBILITIES

Many papers were devoted to regulatory matters. Richard Rawl (IAEA) reported on the implementation of the revised “Regulations for the Safe Transport of Radioactive Material”, IAEA Safety Standard ST-1, published in 1996. A re-evaluation of the IAEA review and revision process was initiated shortly after the issue of ST-1. Gerardus Dicke (IAEA) reported a proposal to change to a 2 year cycle because it offers significant advantages over the 10 year cycle which was used previously. Such a move will help to keep the regulations up to date, provide flexibility and be in line with the revision process for other international dangerous goods transport.

The changes to ST-1 are being considered by the UN Committee of Experts on the Transport of Dangerous Goods, the IMO and the ICAO. Work is proceeding with the aim of issuing a revision of ST-1 in compliance with this new format by 1 January 2001. Parallel work on the corresponding international documents (IMDG Code, ICAO technical literature, ADR & RID) has also started.

W A Grant (AECB, Canada) reported on similar changes within Canada to those in France, which shift the emphasis of nuclear safety and control from national security to health, safety and protection of the environment. The changes are designed to separate the functions of the renamed Canadian Nuclear Safety Committee from the nuclear research, architect/engineering, development and marketing aspects of Atomic Energy of Canada Ltd (AECL).

SEA TRANSPORT

A significant fraction of the conference time was devoted to papers reporting on various aspects of the sea transport of RAM, particularly the reprocessed material passing between Europe and Japan. The topics covered included shipboard fires, collisions, environmental impact, risk assessment, operational experience and public relations. The focus on sea transport is a result of various events which occurred in the early 1990s, of which the most important was the adoption in 1993 by the IMO of the “Code for the Safe Carriage of Irradiated Nuclear Fuel, Plutonium and High-Level Radioactive Wastes in Flasks on Board Ships”. This code, usually referred to as the INF Code, put an accent on maritime RAM transport and led the IAEA to set up a Co-ordinated Research Programme (CRP) to study the safety aspects. The INF code, although voluntary at its inception, is expected to be made mandatory from the important regulatory date of 1 January 2001.

URANIUM HEXAFLUORIDE

Seven papers reported on various aspects of the design and behaviour of uranium hexafluoride packages, particularly under fire accident conditions. The new edition of ST-1 requires that a UF6 container shall withstand a specified fire test and work has been carried out to assess the risk of rupture under such conditions. This has led to a joint research project called TENERIFE carried out by IPSN in France and CRIEPI (Central Research Institute of the Electric Power Industry) in Japan, resulting in the formulation of a model of the complex thermohydraulic behaviour, the DIBONA Code. There were several papers examining whether an unprotected 48Y cylinder would survive the fire test specified in paragraph 728 of ST-1. Because the results indicate that the unprotected cylinder may only just survive the regulatory fire, overpacks may be expected to become the norm.

CRITICALITY

A dozen papers from Egypt, France, Japan, Korea and the USA were focussed on criticality aspects, particularly the substantial benefits from taking credit for the reduced reactivity of irradiated fuel. William Lake (USDOE) gave the results of a US federal waste management study based on transporting the existing inventory of PWR assemblies to a repository.

PLUTONIUM TRANSPORT

IAEA ST-1 contained various changes which affect the transport of plutonium, including the specification of a new type of air transportable package which must withstand an impact at a speed of 90 m2/sec. Xavier Gaultier (Transnucléaire, France) unveiled details of a new Type C design (illustrated on previous page), the result of a totally new approach to meet the high impact test velocity specified. Qualification tests are expected in the year 2000.

Development of a second generation of packagings for surface transport of fresh MOX fuel is ongoing. Yves Rouquette described Cogema’s FS 65 packaging whilst Peter Purcell (BNFL) described a similar concept designated EuroMOX. Both packagings can accommodate BWR or PWR fuel assemblies.

A TRANSPORT INES

One poster paper on the development of criteria for a Transport Event Scale deserved the larger forum of a Conference lecture. A transport event may involve partial loss of shielding and/or a release of radioactivity. However a Transport Event Scale has not yet been brought into force even though the International Nuclear Event Scale (INES) has been in existence for 6 years for nuclear installations. In view of the evident concern about RAM transport, heightened by the media reports of rail wagon contamination which were circulating during the conference, introduction of a Transport Event Scale should be given special priority. Since an event scale different from INES could lead to misunderstanding, it would be sensible to extend the current INES to embrace transport events.

PUBLIC PERCEPTIONS

Transport of RAM is a key part of the nuclear industry and because it is a world-wide business, a minor mishap anywhere in the world could affect another part of the industry in a completely different part of the world. It is surprising that PATRAM has not devoted sessions to public relations aspects for the last decade. This time that deficiency was rectified.

Gavin Carter (BNFL Inc) described how negative perceptions of the transport of vitrified high level waste had been challenged by a pro-active communications strategy undertaken jointly by the Overseas Reprocessing Committee of Japan, BNFL (UK) and Cogema (France). He gave an analysis of how misrepresentations and misunderstandings can arise or be deliberately promoted, adding that the prime aim of anti-nuclear pressure groups was not to make transport safer. Their goal is wider – the abolition of the nuclear industry.

The speakers introduced the audience to examples of the strategy and tactics used by anti-nuclear opponents. They also discussed the basis for the safety culture as defined in IAEA Safety Series No 75 and stressed the vital need for transparency, clarity and openness. It would be useful to revisit the subject and re-examine the papers in this section when the “media event” of rail wagon contamination has been properly assessed.

Richard Yoshimura (Sandia Laboratories, USA) published US database information about RAM transport for the 25 year period to 1996. The information is an important confirmation of the de facto safety situation. Details of rail shipments of RAM over a similar time span were reported by the German Federal Railway Office.

OTHER TOPICS

Other sessions were devoted to the LSA/SCO (low specific activity/surface contaminated object) category of materials, package design, thermal analysis, impact behaviour, sealing, transport systems, operations, on-site transfers, radiological impact and risk assessment. The 1873 pages of text in the conference proceedings provide an excellent source-book for the current state of the art in RAM transport.