High-Level Waste Disposal Facility Confinement

DOE-HDBK-1132-99

Instrumentation and control systems should be required at an RSWF to

provide monitoring and control capabilities associated with confinement,

nuclear criticality safety, and radiation protection.

High-Level Waste Disposal Facility Confinement . During the short-term

period following emplacement when short-lived nuclides dominate the hazards

associated with a disposal facility, the engineered system of barriers should

remain effective and should contain the emplaced wastes. Typically, this time

period is considered to include at least 300 years but not more than 1,000

years following permanent closure. Technical criteria associated with the

engineered system of barriers should address the following:

establishment of a high-integrity confinement system during emplacement (to

limit the rate of release of radionuclides from the system),

in situ stresses affecting the engineered system of barriers,

corrosion affecting the engineered system of barriers,

radiological effects on barrier integrity, and

contact with groundwater.

During the long-term period, reliance should not be placed on the engineered

system of barriers to contain emplaced waste. Confinement during the long-

term period should be accomplished by the geologic setting. Technical criteria

associated with the geologic setting should address the following:

leaching characteristics of waste and waste binders;

site and soil characteristics, including fractures, porosity, hydraulic

conductivity, sorption, hydraulic gradient, and thermal gradient;

long-term geologic stability;

groundwater travel time;

absence of resources that would be an incentive for human intrusion; and

stability of rock mass.

I-82