Domestic smoke detector disposal in Australia

[George.Koperski@nt.gov.au]

Dear Radsafers



As  the disposal of domestic smoke detectors (DSD) became a prominent discussion

topic  of  the  past  24 hours, I thought it might be of interest to the List to

share  the information on how disposal of domestic smoke detectors is dealt with

elsewhere.



DSD sold in Australia almost exclusively contain Am-241. When significant number

of  them  are  intended for bulk disposal they are treated as radioactive waste.

Their  disposal  must  meet  the requirements of the National Health and Medical

Research  Council  (NHMRC)  "Code  of  Practice for the Near Surface Disposal of

Radioactive Waste in Australia (1992)".



For disposal of individual, or a small number (= several) of DSD, arrangements

vary between the eight State and Territory jurisdictions. In some they can be

disposed of with domestic rubbish, in the other they must be returned either to

respective radiation protection authorities or to the supplier (although there

is no practical way of enforcing this). Labels to that respect are permanently

attached to the DSD units. The advice to the consumers is that the units should

not be dismantled before disposal.



Assessments  of  radiation  risks  of  DSD done over the last decade (references

available  on request), which also included disposal, have led to the conclusion

that  disposal  of  individual  DSD with domestic rubbish does not represent any

radiological hazard from environmental or public health perspective. The reasons

behind this conclusion are:

-    very small amount  of Am-241 in each detector (max 37 kBq,  or 1

microcurie)

-    secure binding of the radioactive material to a metal foil inside the unit,

and

-    the fact that the typical amount of naturally occurring alpha radioactivity

in soils is equivalent to a dozen or more DSD in every cubic metre.

Consequently, dispersal of even a large number of DSD through the landfill is

not significant in comparison.



The  emerging  consensus  on the above among all the Australian jurisdictions is

likely  to  lead  to  the  uniform  adoption  of  the landfill disposal practice

nationwide.



The same approach has already become an accepted practice in the UK (Documents

of the NRPB, vol 3, No 2, 1992) and in New Zealand (NRL Report 1996/2).



However, there is a potential twist on the matter.

The trend towards segregation of domestic rubbish at landfill sites could lead

to concentration, rather than dispersal of DSD, hence to concentration of the

radioactive waste. This would negate the dilution or radioactivity by random

dispersion of DSD in the rubbish. Consequently, the practice of  segregating

rubbish at landfill sites should not be applied to DSD.





George Koperski PhD

Manager, Radiation Health

Department of Health

and Community Services

Darwin, NT, Australia

george.koperski@nt.gov.au



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