Reducing characterization costs by 30 per cent through the use of an innovative drilling strategy

Balancing the cost of through site characterization against the uncertainties encountered during remedial action has always been a primary goal of the U.S. Department of Energy's Formerly Utilized Sites Remedial Action Program (FUSRAP). This paper reports how this goal has been achieved through the development of an iterative sampling process for the characterization of radioactively contaminated sites covering large areas. The iterative process utilizes historical information to make preliminary predictions of the horizontal boundaries of contamination. Once the preliminary boundary has been established, a systematic sampling program is conducted around the boundary. If the boundary sampling program fails to establish the horizontal boundaries of the waste, the systematic boundary search is extended in an iterative manner. After the boundaries have been established, sampling intervals within the boundaries are reduced and additional samples are collected to determine the depth of the contamination and the consistency of the waste. Biased samples may also be taken to examine any unique features or anomalies identified at any point during the characterization