[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: clearance thresholds
Hi Marco,
I am assuming from your note that the readers of the waste management
magazine will mostly be based in Spain. As such they should be subject to
Spanish laws which have been adopted/implemented to comply with the
(European Union) Council Directive 96/29/Euratom of 13 May 1996. Under this
directive all member states of the European union were required to put in
place national legislation to comply with the above directive, usually known
(in the UK) as the revised basic safety standards directive.
Much of the contents of the directive 96/29/Euratom was concerned with
occupational exposure and the implementation in Europe of the
recommendations of ICRP 60.
However it also include a requirement for the production of legislation for
the authorisation and clearance for disposal, recycling or reuse of
radioactive substances or materials containing radioactive substances
arising from any practice subject to the requirement of reporting or
authoristation (Article 5, 1, of the directive) i.e ionising radiation
emanating from an artificial source or from a natural radiation source in
cases where natural radionuclides are or have been processed in view of
their radioactive, fissile or fertile properties (Article 2,1, of the
directive).
Apologies for the previous bit - put simply any clearance of any artificial
radioactivity, or natural radioactivity processed for its radioactive and/or
fissile/fertile properties must be authorised. EXCEPT the disposal,
recycling or reuse of such substances or materials may be released from the
requirements of this directive provided they comply with clearance levels
established by national competent authorities. These clearance levels shall
follow the basic criteria used in Annexe 1 (of the directive) and shall take
into account any other technical guidance provided by the community (Article
5, 2 of the Directive). This means that Spain should have adopted clearance
criteria to allow the disposal, recycling or reuse of materials containing
artifical radioactivity or natural etc. (see above) to comply with the
directive.
The requirements of annexe 1 are as follows:
a) the effective dose expected to be incurred by a member of the public
(and this includes all workers who may come into contact with the material
once it has been released e.g. for metals, scrap metal workers, haulage
contractors, foundry workers, workers in manufacturing facilities using the
metals etc.) due to the exempted practice is of the order of 10 microSv or
less in a year. Marco, this is probably where your 10 microSv value came
from. (Note in the UK, in the order of 10 microSv was regarded as
approximate i.e. it could be a little higher or lower than this value).
b) either the collective effective dose commited by one year of
performance of the practice is no more than about 1 manSv or an assessment
of the optimisation of protection shows that exemption is the optimum
option.
In the UK an assessment was undertaken by an independant contractor on
behalf of the government. This reviwed existing legislation against the new
EU directive. The conclusion of the review was that there was no need for a
change in the existing clearance level of 0.4 Bq/g for all artificial
radionuclides. The review found that 330 radionuclides could be assigned to
one of three groups. The first group would meet the criteria using a level
of 0.1 Bq/g, the second using a criteria of 1 Bq/g and the third using a
criteria of 10 Bq/g. Given that the directive specified an effective dose
IN THE ORDER OF 10 microSv per year, it was the view that this could be
achieved using a the single criteria of 0.4 Bq/g even though the highest
doses would be in the order of 40 microSv year. These doses would only
occur if very large quantities of the group 1 materials were released for
disposal, re-use or recycling.
Unfortunately, many other countries in the EU also went and undertook their
own calculations to meet the EU directive. This means that unfortunately
there is no common set of clearance levels within the EU. For the purposes
of your article it will be difficult to specify numerical values for these
materials. The best you could achive is to try and identify what values
were adopted within Spain. This will at least allow you to identify what
materials can be used, stored handled, treated etc. in Spain before they
require some for of authorisation from the Spanish Environmental Department?
If individauals or companies in Spain wish to import or export to other EU
countries they will also need to comply with the regulations in force in the
country of origin, any countries that the material may transit through and
the final country where the material end up.
Further information can be found in the following publications:
1) IAEA, 1996. Clearance levels for radionuclides in solid materials.
IAEA-TECDOC-855, IAEA, Vienna
2) Working Party of the Article 31 Group of Experts, 1998. Recommended
radiological protection criteria for the recycling of metals from
dismantling of nuclear installations. EC report RP89, European Commission,
Luxembourg.
3) SSK, 1998. Clearance of materials, buildings and sites with negligible
radioactivity from practices subject to reporting or authorisation. Heft
16, Gustav Fisher, Stuttgart.
Moving on to your second value of 1 microSv/hr in contact with scrap metals.
I'm unaware of the origin of this figure. However it is easy to see that
dose rates at this level are unlikely to comply with the requiremnt to
restrict doses to members of the public (that is all individuals exposed
after the
materials have been released) to less than 10 microSv/y. Although I would
be interested if you could let me know where this value came from.
The final value you mention is 70 Bq/g. This comes from the definition of
radioactive material given inthe IAEA Transport regulations - Safety series
6 i.e. Radioactive Material shall mean any material having a Specific
Activity greater than 70 kiloBq/kg.
You should be aware that the IAEA transport regulations have been revised
and are now called IAEA TS-R-1 (ST-1), these have been the subject of some
other discussion on the radsafe list recently. I understand (and hope
others on
the list can confirm) that the new regulations have indivual limits for
individual
radionuclides (both total activity and specific activity) in a table which
identifies
the quantity of material that is "exempt" from the requirements of the IAEA
transport regulations. However it is important to remember two things,
firstly
these limits only apply to transport, NOT accumulation, storage or disposal,
reuse
recycling, these will have to comply with any relevant national legislation
implemented to comply with the EU Directive. Secondly you will have to
check which
values apply in Spain, the country of origin, any countries you may wish to
ship through
and the final destination country. These may or may not have updated their
national
legislation to reflect the new IAEA transport regulations (see recent
posting
on radsafe "Two Common New Transportation Errors").
I wish I had been able to provide definitive limits for these materials in
Europe,
unfortunatley as you can see EU legislation does not always achieve its
purpose.
Good luck in your task.
Regards
Julian Ginniver
----- Original Message -----
From: "Marco Caceci" <mcaceci@radal.com>
To: "Radsafe (E-mail)" <radsafe@list.vanderbilt.edu>
Sent: Monday, July 30, 2001 8:22 AM
Subject: clearance thresholds
> Hi:
>
> I am writing a paper for a (Spanish) waste management trade magazine on
the issue of radiation protection.
> This is a non-peer-reviewed article, so if anybody could volunteer to
review it (it is in Spanish) please let me know, I would
> really appreciate...
>
> Presently I find it difficult to locate primary sources and references for
clearance limits and criteria for acceptance of incoming
> materials and products.
> Any expert out there could check these statements and tell me if they are
true? do you have any reference to relevant laws and
> regulations?
>
> to be considered 'non radioactive'...
>
> - underlying criteria is that no member of the public should be subject
(by a product such as recycled aluminum or steel) to a dose
> higher than 10 uSv in a year
>
> - product (such as Al or steel) or raw material (scrap) should emit less
then 1 uSv/h at contact
>
> - product should contain less then 70 Bq/g activity
>
> Thank you in advance...
>
> Marco Caceci
> LQC s.l.
> www.radal.com
> www.chemitech.com
>
> ************************************************************************
> You are currently subscribed to the Radsafe mailing list. To unsubscribe,
> send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
> radsafe" (no quote marks) in the body of the e-mail, with no subject line.
>
>
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.