The Royal Society of Edinburgh is pleased to respond to the Scottish Office Agriculture, Environment and Fisheries Department’s consultation on Basic Safety Standards Directive Euratom 96/29. The RSE is Scotland’s premier Learned Society, comprising Fellows elected on the basis of their distinction, from the full range of academic disciplines, and from industry, commerce and the professions. This response has been compiled with the assistance of a number of Fellows with direct experience in research and management of radioactivity and radioactive waste.
The Society welcomes this move towards the filling of an important gap in the radiological protection of workers and the public with particular regard to exposures resulting from practices and disposals involving Naturally Occurring Radioactive Materials (known internationally as ‘NORM’) and Technologically Enhanced Natural Radioactivity (‘TENR’). Until now, different standards of radiation protection have been applied in that enhanced natural and man-made radioactivity have been treated very differently, despite being essentially identical with regard to radiotoxicity. The proposed revision of the UK's legislation will certainly reduce this anomaly which potentially affects many workers in a whole range of ‘non-nuclear’ industries.
Future consideration should also be given to the fact that the legislation continues to perpetuate a philosophy which is entirely based on controlling the health effects on humans and assumes that if mankind is protected then so too will all organisms and the environment in general. The ICRP/IAEA have for some years been responding to the challenges imposed by the Rio/UNCED process (biodiversity, precautionary principle etc.) and specifically to the philosophy that if man is to be secure so also must be our biodiverse world. Thus, as applied to protection from other pollutants, regulations on radionuclides in the environment and workplace should be focused not only on man but also on environmental flora and fauna. Such guidance takes note of the obvious instances where, particularly in cases of environmental disposals and waste dumps on land and at sea, man is certainly unlikely to be first in line for exposure.
It is also worth noting that, through revisions such as the proposed in the UK and other developed countries, working conditions and radiation exposures associated with ‘non-nuclear’ industries are being greatly improved, either by improving practices or, less desirably, by making continuing operations there uneconomic and hence closing factories. One undesirable net result of such legislation is that potentially hazardous industrial practices are being exported to countries where appropriate safety legislation is deficient or absent. While this trend is not necessarily a matter for inclusion in the UK's revision of this particular legislation, the statutory authorities should be aware of this negative trend and seek to assist and advise such countries to protect against these health risks. UK companies might also be encouraged to take a responsible interest in conditions prevailing in TENR/NORM-supplier companies in these countries.
The specific questions identified in the consultation document are addressed below:
- Natural and Artificial Radioactivity (Para 38-42):
- Are you in favour of retaining the distinction between the regulation of materials containing only natural radioactivity and those containing man-made radioactivity?
Although the biohazard may depend on factors such as pathways to the biosphere, the specific activity of a given radioisotope is independent of source, and therefore for the purposes of radiation protection there is no difference between materials containing natural and those containing man-made radioactivity. The Society would not, therefore, be in favour of applying different criteria to each. The distinction also creates the impression in the mind of the public that artificial radioactivity somehow differs from natural radioactivity in terms of specific hazard. Doses are in general cumulative and arbitrary distinctions as to origin tend to obfuscate calculation of dose. There are some radioisotopes that have no occurrence in nature; however, there is such a large range of overlap that it is difficult to see rational grounds for a distinction.
The distinction between the two sources is also difficult to sustain. For instance, some man-made nuclides are ubiquitous, such as those from fall-out. Additionally if, for example, an ore is somewhat radioactive, owing to its content of uranium, thorium etc., at what point in subsequent processing of natural materials does it become ‘artificial’? Or again, are radioactive emissions from coal-fired power stations, derived from somewhat radioactive fuel, ‘natural’ or ‘artificial’?.
- Work Activities and Practices (Para 44-46):
Are you in favour of all work activities involving naturally occurring radioactive material continuing to be subject to the same regulatory regime and practices?
The Society would be in favour of all work involving NORM/TENR being subject to the same regulatory regime and practices, as is currently the case under RSA 93, unless specifically excluded or exempted. For example, some chemical and physical processes lead to concentration of naturally occurring radioactivity, such as the alpha particle emitter 210Po.
The Society is concerned, however, over the suggestion in para 45 of the consultation document, that the legislation should allow national discretion where application of the safety regulations would "impose an unacceptable burden". Once regulations are allowed to be discretionary there is no guarantee of public protection and, given the impact of public opinion in this area, all safety regulations should be logical, scientific, transparent and seen to be so.
- Revision of Schedule 1 – For Solid Materials (Para 48-58):
Are you in favour of changing the Schedule 1 levels for solid materials? If so, what are the relative merits of any other levels against the retention of the existing value?
The Society would be in favour of changing the Schedule 1 levels for solids. New levels should be nuclide-specific, rather than radioelement-specific, as most exposures involve individual (or families of) nuclides. The levels should also make it easy to combine the contributions by decay products whether in secular equilibrium or not. The lower, more conservative values for natural radionuclides in column 3 of Table 1b (p.31) would be most desirable and would have the greatest apparent equivalence to the values for man-made radionuclides.
- Revision of Schedule 1 Liquids and Gases (Para 60-63):
Are you in favour of changing the Schedule 1 Levels for liquids and gases? And if so, what are the relative merits of any other levels against the retention of the existing values?
The Society would also be in favour of changing the Schedule 1 levels for liquids and gases, for similar reasons to that for solids (above).
- Revision of the Substances of Low Activity Exemption Order (Para 65-72):
Are you in favour of changing the SoLA level of 0.4 Bq/g for solid materials? And if so, what are the relative merits of any other levels against the retention of the existing values?
The Society would be in favour of changing the SoLA of 0.4 Bq/g for solid materials. A principal threshold of 1 in a million should be used across the board as a threshold of risk to members of the public from accidental exposure to radioactive materials, as it is a figure understood by ministers and the public and a level of risk they find acceptable. It would also provide a single consistent basis for the whole process. In order to demonstrate and acknowledge the widely different radiotoxicities of different nuclides, however, this calculation should also take into account the factors included in the Table 4 Minimum Clearance Level calculations (p. 33-41). This approach would have the merit of basing the new regulations on detailed science and possess a credibility important in matters of public health. If grouping of clearance levels was to be used, however, there would be merit in four, rather than three, radionuclide clearance level groups, with an extra group for relatively harmless radionuclides.
- Rationalisation of the System of Regulation Using Exception Orders (Para 74-82):
- Should there be a review and rationalisation of existing orders to bring them up to date and address developments since they were first issued? Or a more radical approach replacing some orders with more generally applicable generic authorisations covering wider classes of practices?
The Society believes that there should be a more radical approach replacing some exception orders with more generally applicable generic authorisations covering wider classes of practices. This particular area has grown disjointedly over the decades and a completely new and modern fresh approach is merited. Care would, of course, be needed in the framing of the generic authorisations.
- Are there any other comments you would like to make on the consultation which have not been addressed by the questionnaire?
- The Society would like to point out that in the Council Directive, Title I, Definitions (p.50 of the consultation document) the definition of Activity (A) is wrong when quoted as: dN/dt.
Rather it should be: A = ? N,
where ? is the disintegration constant, and N the number of active nuclei. In most cases:?N = - dN/dt (as stated)
However, in a decay chain: dN/dt = Production rate – decay rate
= P – ?N
where P is the decay rate of the parent substance. The definition requires dN to be a specific type of change, i.e. decay, rather than the total change in N with time, as is implied by the notationdN
Further information is available from the Research Officer, Dr Marc Rands