US EPA

1425570 

Technical Report 

Comprehensive Strategy of Hydrogeologic Modeling and Uncertainty Analysis for Nuclear Facilities and Sites 

Newman, SP; Wierenga, PJ 

2003 

NTIS/02925382 

GRA and I 

GRA and I 

This report describes a strategy that embodies a systematic and comprehensive a pproach to hydrogeologic conceptualization, model development and predictive uncertainty analysis. The strategy is comprehe nsive in that it considers all stages of model building and accounts jointly for uncertainties that arise at each of them. The stages include regional and site characterization, hydrogeologic conceptualization, development of conceptual-mathematical model structure, parameter estimation on the basis of monitored system behavior, and assessment of predictive uncertainty. In addi tion to parameter uncertainty, the strategy concerns itself with uncertainties arising from incomplete definitions of (1) t he conceptual framework that determines model structure, (2) spatial and temporal variations in hydrologic variables that are either not fully captured by the available data or not fully resolved by the model, and (3) the scaling behavior of hydrogeologic variables. The strategy is generic but designed to be of practical use to NRC licensing staff in their review of decommissionin g plans, and performance assessment of high-level and low-level radioactive waste disposal sites as well as uranium recovery facilities. An important component of the strategy is a systematic sequence of logical questions, guidelines and criteria with analytical methods appropriate for NRC review and performance evaluation. 

Nuclear facilities; *Hydrogeology; *Uncertainty; *Ground water; *Water flow; Computerized simulation; Performance evaluation; Site characterization; Transport; Nuclear waste disposal; Hydrology