Saxton: Soil Survey II
SMCM Soil Survey
December 2004 - February 2005
Deployment to GPU's Saxton site came within 30 days of notice to proceed on a survey of an estimated 8,000 tons of soils and ash contaminated with Cs-137. This is the third major deployment of the SMCM radiation monitoring system on a conveyor for soil sorting. GPU provided the material handling systems and SRA integrated the SMCM monitoring system. The release limits were 5.6 pCi/g averaged over 300 kg and a 1 uCi Cs-137 point source in the worst location (bottom of the soil at the outside edge). The SMCM operated with a de-rated alarm set point of 2.9 pCi/g. Complete setup, calibration and integration took 20 hours over the course of 3 days. The conveyor/sorting system can process 50 tons per hour, and 360 was attained on the third 10 hour work day (just one week after arrival). Early results show excellent agreement with the (NRC approved) on site lab. Regulatory reaction to the system (both State of PA and NRC) has been positive. The processed material was dug from the old decontamination tank areas as well as sites where SRA had previously identified Cs-137 outliers during a open land survey with a truck mounted SMCM (Fall 2001 (link to other history blurb?). Some of the SMCM characterization data during that survey was for deposits covered with up to four feet of overburden (providing more than 3 orders of magnitude shielding for the surface). The buried deposits that were found ranged from 1,000 to 10,000 pCi/g and were undetectable with conventional instruments.
Contact:
Bob Holmes (717) 948-8637 Saxton Plant/GPU Inc.
