7.7 Radioactive Debris
71
comparison, if the
60 Co is well-mixed and alloyed with 1 kg of other metals and is
divided into particles of the same size there will be 350 billion particles and a much
larger area will be contaminated by the same RDD, albeit to a lower concentration
of radioactivity per unit area.
The area in which an RDD is used will also affect its impact. The release, covert
or explosive, of radioactivity in an area surrounded by skyscrapers will result in
the contamination of many expensive buildings and will produce a larger economic
impact than a release in a less-built area. Winds can also be redirected and concentrated when passing between skyscrapers—the “urban canyon” effect—so radioactivity released in an area filled with skyscrapers will end up being transported along
the axis of the urban street grid (instead of in the direction of the prevailing winds)
and will travel further at higher velocities than if released in a more open area. At
the same time, the presence of tall buildings can absorb the majority of the blast
wave and contamination, reducing the extent of blast damage and the spread of large
concentrations of contamination downwind.
Another factor to consider is the effect of contamination on the buildings themselves. In particular, contamination on building exteriors is relatively easy to wash
off and might even be ignored at high elevations. However, contamination that enters
the building ventilation system will spread throughout the structure, contaminating
the ventilation system and possibly the entire interior volume as well if ventilation is
not turned off quickly. Given the high cost of real estate and of construction, this can
lead to a very high economic impact if valuable real estate must be removed from
service, demolished, disposed of as radioactive waste, and rebuilt.
The extent of radioactive contamination—the buildings and land contaminated by
radioactive debris—will, to a large part, determine the overall financial and societal
impact of an RDD. If the contamination does not spread far, if few structures are
contaminated and if the contamination does not contaminate a large amount of a
city’s infrastructure then the overall impact of the RDD will be far lower than if
hundreds of buildings must be decontaminated and demolished at a cost of hundreds
of billions of dollars.
References
1. World Health Organization (2013) Health risk assessment from the nuclear accident after the
2011 Great East Japan Earthquake and Tsunami, based on a preliminary dose estimation. World
Health Organization, Geneva Switzerland
2. Meyer R, Kohler J, Hormburg A (2007) Explosives, 6th edn. Wiley, New York
3. Akhavan J (2011) The chemistry of explosives, 3rd edn. Royal Society of Chemistry, Cambridge
UK
4. Davis T (1943) Chemistry of powder and explosives. Wiley, New York
5. Federal Emergency Management Agency (2003) Primer for design of commercial buildings
to mitigate terrorist attacks. FEMA, Washington DC
6. Federal Emergency Management Agency (1996) The Oklahoma City bombing: improving
building performance through Multi-Hazard Mitigation. FEMA, Washington DC
71
comparison, if the
60 Co is well-mixed and alloyed with 1 kg of other metals and is
divided into particles of the same size there will be 350 billion particles and a much
larger area will be contaminated by the same RDD, albeit to a lower concentration
of radioactivity per unit area.
The area in which an RDD is used will also affect its impact. The release, covert
or explosive, of radioactivity in an area surrounded by skyscrapers will result in
the contamination of many expensive buildings and will produce a larger economic
impact than a release in a less-built area. Winds can also be redirected and concentrated when passing between skyscrapers—the “urban canyon” effect—so radioactivity released in an area filled with skyscrapers will end up being transported along
the axis of the urban street grid (instead of in the direction of the prevailing winds)
and will travel further at higher velocities than if released in a more open area. At
the same time, the presence of tall buildings can absorb the majority of the blast
wave and contamination, reducing the extent of blast damage and the spread of large
concentrations of contamination downwind.
Another factor to consider is the effect of contamination on the buildings themselves. In particular, contamination on building exteriors is relatively easy to wash
off and might even be ignored at high elevations. However, contamination that enters
the building ventilation system will spread throughout the structure, contaminating
the ventilation system and possibly the entire interior volume as well if ventilation is
not turned off quickly. Given the high cost of real estate and of construction, this can
lead to a very high economic impact if valuable real estate must be removed from
service, demolished, disposed of as radioactive waste, and rebuilt.
The extent of radioactive contamination—the buildings and land contaminated by
radioactive debris—will, to a large part, determine the overall financial and societal
impact of an RDD. If the contamination does not spread far, if few structures are
contaminated and if the contamination does not contaminate a large amount of a
city’s infrastructure then the overall impact of the RDD will be far lower than if
hundreds of buildings must be decontaminated and demolished at a cost of hundreds
of billions of dollars.
References
1. World Health Organization (2013) Health risk assessment from the nuclear accident after the
2011 Great East Japan Earthquake and Tsunami, based on a preliminary dose estimation. World
Health Organization, Geneva Switzerland
2. Meyer R, Kohler J, Hormburg A (2007) Explosives, 6th edn. Wiley, New York
3. Akhavan J (2011) The chemistry of explosives, 3rd edn. Royal Society of Chemistry, Cambridge
UK
4. Davis T (1943) Chemistry of powder and explosives. Wiley, New York
5. Federal Emergency Management Agency (2003) Primer for design of commercial buildings
to mitigate terrorist attacks. FEMA, Washington DC
6. Federal Emergency Management Agency (1996) The Oklahoma City bombing: improving
building performance through Multi-Hazard Mitigation. FEMA, Washington DC