IAEA-TECDOC-1231 Severity, probability and risk of accidents during maritime transport of radioactive material Final report of a co-ordinated research project 1995–1999 July 2001 The originating Section of this publication in the IAEA was: Radiation Safety Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 A-1400 Vienna, Austria SEVERITY, PROBABILITY AND RISK OF ACCIDENTS DURING MARITIME TRANSPORT OF RADIOACTIVE MATERIAL IAEA, VIENNA, 2001 IAEA-TECDOC-1231 ISSN 1011–4289 © IAEA, 2001 Printed by the IAEA in Austria July 2001 FOREWORD In the 1990s, the maritime transport of radioactive material, in particular the shipments from France to Japan of plutonium, of high level vitrified wastes and of fresh mixed oxide (MOX) fuel, attracted much publicity. In 1992, a Joint International Atomic Energy Agency/International Maritime Organization/ United Nations Environment Programme Working Group on the Safe Carriage of Irradiated Nuclear Fuel and other Radioactive Materials by Sea considered many safety aspects associated with plutonium transports. The group recommended that the three organizations adopt a draft code of practice for the Safe Carriage of Irradiated Nuclear Fuel, Plutonium, and High Level Radioactive Wastes on Board Ships. The group further considered a number of issues related to accidents at sea, accident statistics, risk studies and emergency response. The group concluded that all the information available in this area demonstrated that there were very low levels of radiological risk and environmental consequences from the transport of radioactive material. The group further recommended that the matter be kept under review by the three organizations involved. In its ninth meeting, held in Vienna in 1993, the Standing Advisory Group on the Safe Transport of Radioactive Material (SAGSTRAM) recommended that a new co-ordinated research project (CRP) be set up to study the fire environment on board ships. This task was meant to tie in with the recommendations of the Joint Working Group to keep matters related to sea transport of radioactive material under review. The resulting CRP on the severity of accidents in the maritime transport of radioactive material involved participants from five countries and extended over a period of approximately five years. This TECDOC represents the final outcome of the work done in the course of many meetings spread over five years. A list of contributors to drafting and review can be found at the end of this report. The IAEA officer responsible for this publication was X. Bernard-Bruls of the Division of Radiation and Waste Safety. EDITORIAL NOTE This publication has been prepared from the original material as submitted by the authors. The views expressed do not necessarily reflect those of the IAEA, the governments of the nominating Member States or the nominating organizations. The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. The authors are responsible for having obtained the necessary permission for the IAEA to reproduce, translate or use material from sources already protected by copyrights. CONTENTS 1. INTRODUCTION .............................................................................................................1 2. SCOPE...............................................................................................................................2 2.1. Type of materials and packaging..............................................................................3 2.2. Types of ships ..........................................................................................................3 2.3. Accident environment ..............................................................................................4 2.4. Effects of accidents ..................................................................................................4 2.5. Summary of the findings..........................................................................................4 3. HOW RADIOACTIVE MATERIAL IS TRANSPORTED AT SEA...............................5 3.1. Regulatory framework..............................................................................................6 3.1.1. International regulations...............................................................................6 3.1.2. National regulations .....................................................................................8 3.2. Radioactive material package preparation and shipping process by sea..................8 4. PROBABILITY OF SHIP ACCIDENTS........................................................................10 4.1. Introduction............................................................................................................10 4.1.1. Lloyd's databases........................................................................................10 4.1.2. The MAIB, UK ..........................................................................................11 4.1.3. International Maritime Organization..........................................................11 4.1.4. Bureau Véritas............................................................................................11 4.2. Reference studies and statistical analyses of accidents..........................................11 4.2.1. CEPN/IPSN (January 1999, France) ..........................................................11 4.2.2. SRD - AEA TECHNOLOGY-NTL (UK)..................................................13 4.2.3. SeaRAM - SNL (May 1998, USA) ............................................................14 4.2.4. JNC (November 1998, Japan) ....................................................................14 4.2.5. GRS, EC report (November 1998, Germany) ............................................15 4.3. Main results............................................................................................................15 4.3.1. All categories of accidents .........................................................................16 4.3.2. Fire accidents..............................................................................................16 4.3.3. Collision accidents .....................................................................................18 4.3.4. Collision and fire accidents........................................................................21 4.3.5. Foundering .................................................................................................21 4.4. Discussion..............................................................................................................21 4.5. Use of actual route statistics for theoretical routes ................................................22 5. FIRE BEHAVIOUR ON SHIPS......................................................................................23 5.1. Fire scenarios, frequency, effect of ship type.........................................................23 5.1.1. Fire scenarios..............................................................................................23 5.1.2. Frequency ...................................................................................................24 5.1.3. Effect of ship type ......................................................................................26 5.2. Determination of frequency-probability, severity and duration .............................30 5.2.1. Frequency-probability ................................................................................30 5.2.2. Severity and duration..................................................................................35 5.3. Assessment of risk .................................................................................................39 5.3.1. Lange, et al. ...............................................................................................39 5.3.2. Yamamoto, et al. study on engine room fire ..............................................42 5.3.3. Yamamoto, et al. study on plutonium transport operations .......................42 6. COLLISION SEVERITY ................................................................................................44 6.1. Background ............................................................................................................44 6.2. Mechanics of ship-to-ship collisions......................................................................45 6.3. Magnitude of forces acting on RAM packages......................................................46 6.4. Conclusions............................................................................................................46 7. CONSEQUENCES OF ACCIDENTS TO SHIPS TRANSPORTING RAM PACKAGES..........................................................................................................47 7.1. Hypothetical accidents ...........................................................................................47 7.2. Accident probabilities ............................................................................................47 7.3. Radioactive release to the atmosphere ...................................................................48