INTEGRATING MARSSIM AND TRIAD TO ACHEIVE RADIOLOGICAL SITE CLEANUP AND CLOSURE

ABSTRACT The U.S. Army Corps of Engineers (USACE) is conducting cleanup of radiologically contaminated properties as part of the Formerly Utilized Sites Remedial Action Program (FUSRAP). USACE is using guidance provided in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) for establishing that sites satisfy site-specific cleanup requirements. While MARSSIM's focus is on final status surveys and site closure, it also provides an overall framework for initial site characterization and remediation. More recently, the U.S. EPA has presented the Triad approach as a means for streamlining data collection at hazardous waste sites and addressing decision uncertainty. The Triad refers to the combination of the following: 1) systematic planning, 2) dynamic work plans, and 3) real-time measurement technologies. Within the radiological cleanup world, MARSSIM also recognizes and embraces the value of real-time measurement systems. The Rattlesnake Creek FUSRAP site provides an excellent example of how MARSSIM, combined with Triad concepts, can be used to accelerate the characterization, remediation, and closure process at a hazardous waste site, while addressing key site-specific issues such as subsurface contamination, and sparse historical data sets. At Rattlesnake Creek, the USACE developed site-specific Derived Concentration Guideline Level (DCGL) requirements consistent with MARSSIM in response to unexpected contamination, and an Explanation of Significant Differences was prepared for the Record of Decision to address these new concerns. Systematic planning targeted the area of concern and identified data gaps to be addressed before remediation plans were finalized. Pre-remediation sampling and analysis plans were designed to be explicitly consistent with final status survey requirements, allowing data sets to support both excavation planning needs and closure requirements in areas where contamination was not encountered above DCGL standards. Judicious use of real-time technologies such as x-ray fluorescence (XRF) and gamma walkover surveys minimized expensive of off-site alpha spectrometry analyses, while at the same time providing the ability to respond to any unexpected field conditions