Overall Subsurface Ventilation Systems

The purpose of this analysis is to provide a conceptual design for the Subsurface Ventilation System and address the construction, emplacement, monitoring, backfill, and closure ventilation phases. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the Monitored Geologic Repository Project Description Document (CRWMS M and O 1999d) (MGR). This analysis will summarize the ventilation concepts that have developed from the incorporation of recent changes to the Technical Baseline and describe changes to the conceptual ventilation design that have resulted from the thermal management requirements. Ventilation concepts presented in the Viability Assessment Design (VA Design) that have not changed are identified and included. The objective of this analysis is to provide a basis for the System Description Document (SDD) Section 2 that provides input to the SR Consideration Report. The scope of the analysis includes the following tasks: (1) Determine the number of primary shafts based on the emplacement airflow rate required to meet thermal goals and (2) Determine conceptual airflow networks for major repository phases including: Construction; Emplacement; Monitoring; and Closure. In addition evaluate: (1) Radon mitigation concerns and options; (2) Monitoring and control requirement changes needed to meet current guidelines; and (3) The impact on the ventilation system of a radiological release due to a potential subsurface fire involving a waste package