Management of Commercially Generated Radioactive Waste - U.S. ...

6.153
* "Treaty on Principles Governing the Activities of States in the Exploration and Use of
Outer Space Including the Moon and Other Celestial Bodies" (1967)
* "Convention on International Liability for Damage Caused by Space Objects" (1972)
* "Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of
Objects Launched into Outer Space" (1972)
* "Convention on Damage Caused by Foreign Aircraft to Third Parties on the Surface"
(1952)
* "Convention on Registration of Objects Launched into Outer Space" (1976).
This list suggests various issues that would have to be thoroughly explored in this early
decision-making phase, including: (1) accident liability, (2) exclusive use of the lunar
surface or other regions of outer space, and (3) international program involvement (e.g., use
of the sea). These issues relate mainly to accident situations rather than routine
operations.
In addition to these political and international issues, space disposal of nuclear waste
would have a number of legal complexities associated with it, including liability and regula-
tory requirements (e.g., licensing). These concerns would be quite evident not only during,
but also before and after actual implementation. Moreover, legal concerns could lengthen the
time needed to implement a space disposal option.
6.1.8.5 Potential Impacts Over Long Term (Postemplacement)
Postemplacement for the space option is defined as the period of time after achievement
of a stable solar orbit. Potential impacts during this period are analyzed for two different
events: engineering failure and inadvertent human intrusion.
Potential Events
The possibility of sudden failure of a container in solar orbit would be extremely remote.
However, if a container should rupture, for example, as a result of a meteor impact or
degradation over the long term, the contents would be released and begin to spread. The
physical processes by which the nuclear waste material would be dispersed in solar space
include sputtering, thermal diffusion, and interactions with solar radiation and wind. Large
pieces or particles of waste material would be sputtered into smaller particles, which in
turn would disperse. The smallest particles, with radii less than 10- 5 to 10-4 cm, would
be swept out of the solar system by direct solar radiation pressure. Larger particles, those
with radii up to 10-3 to 10-2 cm, would gradually loose momentum through scattering,
charge exchange interactions, and collisions with energetic photons and solar wind protons.
This process, called the Poynting Robertson effect, would cause these particles to begin mov-
ing in toward the sun where they would eventually be vaporized and broken down into smaller
particles. Once this had occurred, the smaller particles would be swept out of the solar
system by solar radiation pressure. This sweeping-out process would take an estimated 1000
to 10,000 years (Brandt 1970). NASA is currently studying this process.