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Re: Release Concentrations
On Thu, 6 Jul 1995 JMUCKERHEIDE@delphi.com wrote:
(Chris Davey wrote:
> > Quoting from C123: "the sum of all doses from all radioisotopes via all
> > methods of release does not exceed 50 uSv in a year for a member of the
> > critical group.")
>
> Inconceivably unbelievable !
> How do they set the "mix" to set individual radionuclide numerical limits if
> they are not site/facility source-specific?
>
> > Yes, pathway analysis was done, but soooo conservatively.
>
> That's for sure. Does anybody have a dose comparison to the "radionuclide
> releases" from drilling a well (i.e., discharging radium, etc, plus radon,
> with decay products, both the short-lived and the committed dose from the
> 20-year half life series), from "routine operation"? How about mining? oil,
> gas, coal? What if we applied the same limts to these "man-made" discharges
> of radioactivity to the environment? Does anybody have a statement to the
> public that "we will spend $xM of the public's money to prevent a release of
> radioactivity to a limit at a tiny (0.xxx) fraction of the discharge from a
> well? compared to what's in the river? compared to burning coal? or other
> practical numbers (not to mention compared to medical uses?
(snip)
> > > Regards, Jim
> > >
> > Believe it or not, the AECB does not have quite the same reputation for
> > being power-hungry that you (Jim) alude to for the government
> > organizations south of our border. Of course, this document may change
> > that perception.
> >
> > Thanks for your comments,
> >
> > Chris Davey
> > RSO CCI Edmonton, Alberta
>
> Chris,
>
> Yes, I always thought AECB was more technically sound. But the politics of an
> issue can drive technical considerations to generate irrational numbers with
> "no choice".
>
> I know I come out pretty strong on this matter, but I don't actually believe
> MOST government personnel or agencies take a blantant approach on this. I do
> believe there are a very few who do. I do believe however, that MANY others
> get "sucked in" to some rationale, with generally good faith, often responding
> to some political will and set up situation, that results in the premise that
> expects to continually ratchets the requirements, and the costs, and meets an
> unspoken need that the US EPA does blatantly, ie, "if the reg does not require
> some new action (cost), it is not an effective regulation". Need or health
> does not enter into the consideration in most cases, often blaming the
> legislature (and often ignoring the testimony that the administration and the
> agency top management provided that caused the legislature to so act).
>
> Thanks for your background on the calculational basis. Do you know where the
> "mix" comes from?
>
> Regards, Jim Muckerheide
Here are a few more isotope examples from C123:
Isotope Bq per m cubed Bq per litre Bq per kg
Ca45 1 300 50
C14 5 9 200
Cr51 30 20000 1000
Co57 0.4 70 20
Cu64 200 100000 6000
F18 400 N/A 20000
Ga67 20 30000 900
Ga68 400 N/A 10000
Au198 4 300 200
H3 2000 300000 80000
In111 20 1000 700
In113m 1000 N/A 50000
I123 30 200000 1000
I125 0.04 200 2
I131 0.03 200 1
Fe59 0.5 80 20
Mn54 0.5 600 20
Mo99 7 10000 300
P32 0.8 1 30
Se75 0.7 300 30
Sr85 2 500 80
S35 4 800 200
Tc99m 1000 40000000 40000
Tl201 80 50 3000
Xe133 200 N/A N/A
Assumptions from C123:
Releases to atmosphere:
That both adults and infants live within 100 m of the facility.
That the point of release is 10 m above the ground.
That locally grown fruits and vegetables are located less than 100 m from
the point of release.
That animals bred for human consumption and forage are located about 500m
from the point of release.
That the mean wind speed is 1 m per sec., building height is 5 m and that
lateral dispersion is limited.
That the occupancy factor for the critical group is 100%, but that it
spends 60% of its time outdoors.
That the critical group obtains one-third of its fruit, vegetables and
meat from the locality.
That the discharge rate is 1 m per sec.
That the facility lifetime is 100 years, allowing for build-up in the
environment.
Releases to Sanitary Sewer System:
That time from release to consumption of water and fish is 48 hours.
That an aquatic dispersion factor of 10 to the minus 2 is used.
That the average annual consumption of water is 730 L for an adult, and
90 L for an infant.
That fish consumption (all from contaminated locality) is 20 kg for an
adult and 1 kg for an infant.
Solid Waste Disposal:
Either by incineration or to landfill.
Landfill -
Assumptions:
Leaching takes 1 year (decay)
One per cent of waste disposed to landfill contains radioisotopes.
Precipitation is 0.3 m per year.
Velocity of percolating water is 110 m per year.
Most waste streams consist of surface contaminated materials or materials
in a readily soluble form.
Incineration -
Critical group lives less than 100 m from the incinerator.
Incinerator stack height of 20 m.
One per cent of waste contains radioisotopes.
100% of radioisotope inventory is released to the atmosphere.
Average incineration rate is 10 kg per sec.
Internal exposure working with incinerator ash -
Mass reduction of 15 to 1, increasing concentration of radioisotopes in ash.
100% of radioisotope inventory is retained in ash.
Time spent handling waste is 2000 hours per year.
External exposure working with incinerator ash -
As with 2nd and 3rd items for internal, plus
Ash assumed to have infinite thickness and infinite lateral extent.
I have only listed the "quickest to transfer to email features", sorry I
don't have time to list all the equations.
Hope this shows how theoretical and super-cautious all this document is.
Also ... hoping for comparison information with US regulations, and
arguments for rejecting this proposed regulatory document, before
research and medical use of radioisotopes in Canada is brought to a
standstill by C123.
Regards,
Chris Davey, RSO.