YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT EAST-WEST DRIFT SYSTEM SAFETY ANALYSIS

The purpose of this analysis is to systematically identify and evaluate hazards related to the design of the Yucca Mountain Project Exploratory Studies Facility (ESF) East-West Cross Drift. This analysis builds upon prior ESF System Safety Analyses and incorporates TS Main Drift scenarios, where applicable, into the East-West Drift scenarios. This System Safety Analysis (SSA) focuses on the personnel safety and health hazards associated with the engineered design of the East-West Drift. The analysis also evaluates other aspects of the East-West Drift, including purchased equipment (e.g., scientific mapping platform) or Systems/Structures/Components (SSCs) and out-of-tolerance conditions. In addition to recommending design mitigation features, the analysis identifies the potential need for procedures, training, or Job Safety Analyses (JSAs). The inclusion of this information in the SSA is intended to assist the organization(s) (e.g., constructor, Safety and Health, design) responsible for these aspects of the East-West Drift in evaluating personnel hazards and augment the information developed by these organizations. The SSA is an integral part of the systems engineering process, whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach is used which incorporates operating experiences and recommendations from vendors, the constructor and the operating contractor. The risk assessment in this analysis characterizes the scenarios associated with East-West Drift SSCs in terms of relative risk and includes recommendations for mitigating all identified hazards. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into SSC designs. (2) Add safety features and capabilities to existing designs. (3) Develop procedures and conduct training to increase worker awareness of potential hazards, reduce exposure to hazards, and inform personnel of the actions required to avoid accidents or correct hazardous conditions. This analysis does not consider temporary construction items and, therefore, does not consider hazards associated with temporary construction items. This analysis will be reviewed and updated to reflect new East-West Drift design changes, construction modifications, and ''as built'' documentation of the East-West Drift when completed. A major difference between this analysis and previous ESF SSAs is the inclusion of hazards that arise as a result of non-accident events, (e.g., ''off-normal'' operations, adverse environmental conditions, or ''out-of-tolerance'' conditions). Non-accident events, that were not included in previous ESF SSAs, include environmental and/or toxic hazards such as leaking gases/fluids, off-gassing reactions, and excessive dust, particulates, exhaust fumes, noise, temperature, etc. which could have an adverse health effect on personnel