Revised guidance on de minimis concept for radioactive waste adopted
Updated guidelines for the application of the de minimis (exempt) concept for radioactive substances which may be considered for dumping at sea have been adopted by Contracting Parties to the treaties which regulate the dumping of wastes at sea.
The 2015 Guidelines for the application of the de minimis concept include recognition of effects of radiation on marine fauna and flora. They were adopted by the 37th Consultative Meeting of Contracting Parties (London Convention 1972) and 10th Meeting of Contracting Parties (London Protocol 1996), which were meeting for their regular joint meeting at IMO in London.
The guidelines refer to the latest advice from the International Atomic Energy Agency (IAEA), including a new procedure to assess doses to workers and members of the public and a similar approach for assessing doses to marine flora and fauna, based on the updated IAEA Safety Standards for protection of people and the environment and recent recommendations by the International Radiological Protection Commission (ICRP) on protection of humans and the environment. While both the London Convention and Protocol ban the dumping of radioactive wastes, certain materials may assigned as “de minimis” (exempt), including natural radionuclides (atoms that have excess nuclear energy, making them unstable) in the environment and in raw materials. De minimis materials could also include materials which have undergone some process which could affect the natural radionuclide composition, but which are deemed not to warrant radiological control since the potential exposure to radiation is too small to warrant regulatory control.
The guidance notes that all materials contain natural radionuclides. Sometimes human activities can result in changes to their concentrations, thus potentially increasing radiation doses. If this occurs, an activity could be subjected to radiological control. Previous human activities, particularly nuclear weapons testing in the atmosphere, have also introduced new radionuclides to the environment and slightly enhanced the overall concentrations of radionuclides. The IAEA advice provides for two distinct categories in relation to the de minimis question: first, cases in which the radionuclide constituents of a candidate material can be automatically (i.e. without further consideration) defined as de minimis; and second, cases in which a specific assessment is required to determine whether the candidate materials are de minimis or not.
In deciding whether candidate materials for dumping at sea could be regarded as ”non-radioactive” (ie de minimis) and therefore may be disposed of at sea, the guidelines recommend that authorities take steps to determine that the radiation risks to individuals caused by the exempted practice or source are sufficiently low that they do not pose any risk and that the exempted practices and sources are inherently safe.
A similar assessment should be carried out in relation to possible impacts on flora and fauna.
The guidance will be made available in due course on the London Convention and Protocol website.
The ban on dumping radioactive waste at sea was adopted in 1993 and there has been no report of deliberate dumping of radioactive wastes and other radioactive matter by Parties since the ban was introduced. The LC/LP Parties are undertaking a comprehensive review of completed studies on the dumping of radioactive waste, to fulfil the requirement of the Convention/Protocol that a 25-year scientific study be conducted relating to all radioactive wastes and other radioactive matter, other than high level wastes or matter. The review is required to be completed by 2019. To date, no Contracting Party has expressed an interest in amending either the LC or the LP to allow the dumping of radioactive wastes and radioactive matter covered by the current ban to be resumed.
Marine geoengineering study initiated
The meetings noted that a new international experts’ working group had recently been established, to explore the possible environmental impacts of marine geoengineering activities, such as those which involve the deliberate introduction of certain elements into the sea in order to stimulate CO2 uptake.
Working Group 41 of the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP), an advisory body that advises the United Nations (UN) system on the scientific aspects of marine environmental protection, will work with relevant organizations with a view to producing a study aimed at providing a better understanding of the potential ecological and social impacts of different approaches to marine geoengineering.
Marine geoengineering is defined as "a deliberate intervention in the marine environment to manipulate natural processes, including to counteract anthropogenic climate change and/or its impacts, and that has the potential to result in deleterious effects, especially where those effects may be widespread, long-lasting or severe". An example of such activity is "ocean fertilization", which involves the introduction of iron, nitrogen or phosphorus compounds into the ocean with the aim of stimulating CO2 uptake by the oceans.
An amendment to the London Protocol adopted in 2013 prohibits the dumping of material for marine geoengineering, except for those activities listed in an annex. Currently, the annex only contains ocean fertilization activity. This may be considered for a permit, if it is assessed as constituting legitimate scientific research taking into account a specific placement assessment framework. The Assessment Framework provides criteria for an initial assessment of a proposal and detailed steps for completion of an environmental assessment, including risk management and monitoring. Importantly, it does not contain a threshold below which experiments would be exempt from its assessment provisions. Every experiment, regardless of size or scale, should be assessed in accordance with the entire Assessment Framework. The anticipated report from the GESAMP Working Group could assist London Protocol Parties to identify other marine geoengineering techniques that could be considered for a permit.
At its recent annual meeting, GESAMP noted that many proposed marine geoengineering techniques or activities are often little more than concepts, but most of them involve potentially large-scale interventions in the ocean with the potential for significant impacts on the marine environment. In addition, many of these activities would likely take place on the high seas, beyond national jurisdictions, and therefore may raise international concerns. While a number of reviews of geoengineering to date have considered a small number of such techniques, mainly for their efficacy, none has reviewed the wider range of marine geoengineering techniques for their marine environmental impacts.
Meanwhile, the meetings noted that presentations from a Science Day on Marine Geoengineering, held in April 2015, can be downloaded from the London convention and Protocol website.
The web-based repository of references relating to the application of the Assessment Framework for Scientific Research Involving Ocean Fertilization is also available.
Marine disposal of mine tailings discussed
The meetings continued their discussion on how best to approach the issue of marine and riverine disposal of mine tailings around the world, in the context of the London Convention and Protocol.
A correspondence group was established, to review and finalize draft terms of reference for a GESAMP Working Group, which would be tasked with identifying and providing a better understanding of potential environmental impacts of marine disposal of tailings or other wastes from land-based mining operations, taking into account potential linkages between deep-water ecosystems at the disposal site and the overlying water column.
The correspondence group was also tasked with continuing to gather information on best practices and existing guidance and legislation relating to marine and riverine disposal of tailings from mining operations on land. The group will also identify any gaps in best practices and existing guidance. The work of the International Seabed Authority (ISA) will also be monitored.
The meetings noted that the outcome and presentations from the GESAMP International Workshop on the Impacts of Mine Tailings in the Marine Environment, held in Lima, Peru, in June 2015 were available on the workshop website.
A 2012 report noted that a total of 15 mines (i.e. 0.6%) out of approximately 2,500 large scale mines world-wide used marine or riverine disposal for mine tailings, under Government permits, and that a number of mines around the world are in the early stages of development and are considering marine disposal of mine tailings.
Guidance under development/review
Correspondence groups were established to develop further guidance on the development of action lists and action levels for dredged material; to develop action lists and action levels for organic material of natural origin; and to review of the specific guidelines for assessment of vessels,