Federal regulations
require us to evaluate how the entire
repository system will function over
10,000 years.
The Total System Performance Assessment calculates the radiation
dose that people living in the area could receive
over the next 10,000 years. The dose calculations consider
the conditions we expect to happen, which include minor
earthquakes and climate change. They also consider unlikely damaging
events, such as major earthquakes and volcanoes.
To evaluate repository safety, federal regulations require
us to calculate the dose from damaging events and the
likelihood of the event’s occurrence in analyses
we call disruptive event scenarios. We add the results
of the disruptive event scenarios to the dose expected
under normal conditions. This sum is compared to the Environmental
Protection Agency’s dose and groundwater standards
for Yucca Mountain.
Using this approach, the radiation doses projected by
the TSPA are substantially below the EPA's standards.
In addition, we use the TSPA to evaluate a separate scenario,
called human-intrusion, which is a hypothetical situation that evaluates the
consequences if someone unknowingly drilled into the repository.
