Society News Archive

19 January 2000

In December 1999, the radiation detectors at a steel-recycling yard in Eastern Ontario found scrap piping from a pulp and paper mill to be radioactive, according to Arthur Scott, Ontario Ministry of Labour.

The piping was returned to the mill where the owners started an investigation and found that the pipes had been removed from the pulp bleaching process some years previously. The field on-contact with the scale inside the pipe was 200 uR per hour. A scale sample contained about 15,000 Bq per kg of Ra-226 and about 4,000 Bq per kg of Th-230.

The bleaching agent used is chlorine dioxide. The process formerly used chlorine gas but there were concerns over releases of chlorinated organics. This may be a new problem for with the chlorine process there was less acid added and hence fewer sulphate atoms and less favorable scale deposition conditions.

More information on this newly discovered NORM finding and its implications will appear in the March issue of the Health Physic Society's Newsletter.