Stontium-90 Contamination in Vegetation from Radioactive Waste Seepage Areas at ORNL (Oak Ridge National Laboratory), and Theoretical Calculations of sup 90 Sr Accumulation by Deer

摘要

This report describes data obtained during a preliminary characterization of sup 90 Sr levels in browse vegetation from the vicinity of seeps adjacent to ORNL solid waste storage areas (SWSA) where deer (Odocoileus virginianus) were suspected to accumulate sup 90 Sr through the food chain. The highest strontium concentrations in plant samples were found at seeps associated with SWSA-5. Strontium-90 concentrations in honeysuckle and/or blackberry shoots from two seeps in SWSA-5 averaged 39 and 19 nCi/g dry weight (DW), respectively. The maximum concentration observed was 90 nCi/g DW. Strontium-90 concentrations in honeysuckle and blackberry shoots averaged 7.4 nCi/g DW in a study area south of SWSA-4, and averaged 1.0 nCi/g DW in fescue grass from a seepage area located on SWSA-4. A simple model (based on metabolic data for mule deer) has been used to describe the theoretical accumulation of sup 90 Sr in bone of whitetail deer following ingestion of contaminated vegetation. These model calculations suggest that if 30 pCi sup 90 Sr/g deer bone is to be the accepted screening level for retaining deer killed on the reservation, then 5-pCi sup 90 Sr/g DW vegetation should be considered as a possible action level in making decisions about the need for remedial measures, because unrestricted access and full utilization of vegetation contaminated with <5 pCi/g DW results in calculated steady-state (maximum) sup 90 Sr bone concentrations of <30 pCi/g in a 45-kg buck. (ERA citation 12:043105)