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
dt
Additional Information
Further information is available from the Research Officer, Dr
Marc Rands
June 1999
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