Re: The Dutch Door Dilemma

["Dr. Peter Hill" <p.hill@fz-juelich.de>]

At 10:31 25.03.98 -0600, Charlie Willis <caw@nrc.gov> wrote:
>RADSAFERS:
>
>Does anyone have more on the story that was reported in the February
>"Nuclear Waste News" that a Dutch Physics Professor found that the
>fire doors in the building where he worked were releasing radiation  at
>levels of 0.8 microsieverts/hr (90 microrem/hr).  It also is said that under
>Dutch law, the owner must have a license for such a door and that, if
>disposed, the door must be disposed as radioactive waste.
>

Dear Charlie, 

in February there was a thread about the Dutch Door Dilemma in the European
Radiation Safety Mailing List RADSAFE-EU, which is cited here in part for
the convenience of radsafers.

Yours Peter Hill 


At 12:16 15.02.98 +0100, A.Klerk <boudewijn.klerk@tip.nl> wrote:
>On a survey through one of our older buildings I found a rise in background
>passing through a set of fire-doors. It occurred that these doors contain
>some radioactive material: about 0,8 microsievert per hour on the surface!
>With a spectrometer it came clear that the activity is natural thorium,
>apparently in glasswool.
>Furthermore the garage-doors in this and other buildings seemed to be even
>more radioactive (because thicker)!
>
>Has anyone experience with this?
>* is this an old problem, or will these still be produced?
>* how about scrapping these doors: is there a hazard?
>* what will be the amount of activity for legislative reasons?
>* is there an alternative?
>* how are these and likewise sources handled in your legislation?
>


At 23:04 15.02.98 +0100, Franz Schoenhofer <schoenho@via.net> wrote:
>....
>If it is glass wool, I would expect that most of the dose would originate
>from K-40. This needs no handling in legislation. Compare 0.8 microsievert
>per hour with the maximum permissible levels of dose for the population. How
>much is background - which has to be subtracted.
>......



At 10:00 16.02.98 +0200, Lauri Kaihola <lauri.kaihola@wallac.fi>  wrote:
>Specific activity of K-40 is 853 pCi/g K or about 30 Bq/g K according to
>Eisenbud (p. 407 in Environmental Radioactivity, 1987) and there is
>about 140 g K in 70 kg man or 4400 Bq of K-40.  ....


At 20:59 16.02.98 +0100, Richard van Sonsbeek <Richard.van.Sonsbeek@wxs.nl>
wrote:
>Dear Boudewijn,
>
>We have experience with doors that contain glass- or stonewool.
>
>As you know metal scrap traders have installed big, and sensitive
>radiation detectors at the entrance gate of their sites.
>
>Therefor, it happens that doors like the ones you described are
>intercepted at scrap yards.
>
>The total specific activity of the glass- or stonewool is about 200
>Bq/g, and therefor, according to Dutch regulations, you need a license
>to possess it. (It is not in its natural matrix, so the limit of 100
>Bq/g apllies instead of the 500 Bq/g.) In practice it means that you
>have to dispose of it as radioactive waste.
>
>With respect to the hazards, I think the fact that you deal with mineral
>fibers, of which the risks are not very well known, is of more concern
>than the fact that it is radioactive.
>


At 21:02 16.02.98 +0100, Arie Klerk <boudewijn.klerk@tip.nl> wrote
referring to K-40:
>And when we than ADD some thorium+daughters, we also have some
>alfa-emitters! The total activity of thorium per door is now estimated to
>some hundreds of kBq together with glass-dust...
>and of course the same amount of each daughter (including Rn-220). No
>problem?
>
>Boudewijn.


At 21:03 16.02.98 +0100, "Ing. A. Klerk" <boudewijn.klerk@tip.nl> wrote:
>you wrote:
>>If it is glass wool, I would expect that most of the dose would originate
>>from K-40.

>To make true what I stated in my original question, I have included the
>spectrum I measured. There is only a small amount of patassium, compared to
>thorium and daughters. And don't say anything about the spectrum, it was
>measured with a simple portable Silena Snip with 3x3" NaI-detector.

>>This needs no handling in legislation. Compare 0.8 microsievert
>>per hour with the maximum permissible levels of dose for the population.
>>How much is background - which has to be subtracted.

>Okay, I did not yet subtract the background. But that was not the problem I
>referred to! How about internal contamination when someone who does not know
>about the risk cuts the doors to pieces? How about the radon in the doors?
>And how about Greenpeace-like people who measure something on a
>scrap-yard???
>
>Boudewijn
>Attachment Converted: "c:\eudora\attach\RADEUR.gif"

Attachment not included in this post. If you want to get it, ask A.Klerk to
mail it directly to you.<mailto:boudewijn.klerk@tip.nl>


At 12:41 18.02.98 +0100, Harald Weiß <weiss@ki.comcity.de> wrote:
>....
>As for the question raised I expect a few tens or even a hundred Bq of
>inhaled thorium- and radon-daughters to be the minor problem if they are
>adsorbed to ten milligrams of glasswool dust (a few 0.001 % of the
>inventory of a door in both cases) you inhale at the same time. But I
>don´t know for sure, either, as I can´t remember having seen figures
>that make the impact of such dust comparable to that of a dose due to
>radioactivity.
>



At 21:45 18.02.98 +0100, "Ing. A. Klerk" <boudewijn.klerk@tip.nl> closed
the thread :
.....
>Everyone should know something about the background as is in the Dutch
>Nuclear Energy Law.
>For any material the limit of radioactivity is still as follows:
>    100 Bq/gram or
>    500 Bq/g for solid natural radioactivity in its natural matrix
>    5 kBq of radiotoxicity group 1
>    50 kBq of group 2
>    500 kBq of group 3
>    5 MBq of group 4
>
>Above these limits the owner needs a license for this "source". Even worse:
>if this owner already has a license for a "real" source, then any activity
>(even below the limits mentioned) must be added to this license (sic!). This
>philosophy is also heard in discussions round the implementation of the new
>Euratom guidelines in the Netherlands.
>
......


Hope this helps some.



Dr.Peter Hill                                phone : +49-2461-61-5081
Forschungszentrum Jülich GmbH                fax   : +49-2461-61-3726
ASS-BS/P                                     mailto: p.hill@fz-juelich.de
D-55245 Jülich

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