Advanced Radiological Scanning and Sorting of CNLs Whiteshell - PowerPoint PPT Presentation

Advanced Radiological Scanning and Sorting of CNL’s Whiteshell Laboratories Experimental Cesium Pond Effluent Soils Steven D. Rima, CHP, CPM Michael P. McDonald, CHP, RRPT Amec Foster Wheeler

Whiteshell Laboratories ► Near Pinawa, Manitoba ► 100 kilometers (km) northeast of Winnipeg ► Nuclear Research and Test Establishment ► Decommissioning since 2003 ► Experimental Cesium Pond Soil ► Shielded Modular Above-Ground Storage (SMAGS) facility soil ► Nuclear Reactor 2

Whiteshell Laboratories Location Add a coloured transparent segment and caption if required. 3

Project Overview Two ponds constructed in 1966 ► 2m deep by 19m diameter and lined with plastic ► Filled with water and allowed to develop “naturally” ► One pond spiked with 18.5 gigabecquerel (GBq) cesium-137 (Cs137) ► Used for over 10 years to study the effect of Cs137 on various ecosystems, including insects ► Cs137 spread both laterally and vertically over the years 4

Project Overview Cesium Pond soil was previously excavated and moved to a Waste Management Area (WMA) ► Approximately 1,700 cubic meters (m 3 ) of soil excavated and stockpiled ► WMA contained other stock-piled materials as well ► Amec Foster Wheeler awarded contract to sort and segregate WMA soils into contaminated (needing eventual disposal as low-level radioactive waste [LLRW]) and “clean” (available for beneficial reuse on site) ► ScanSort SM system & operators deployed to site; operated through severe winter conditions 5

Orion ScanSort SM ► Radiological Soil Sorting Survey System ► Large volume spectroscopy grade sodium iodide (NaI) detectors ► Advanced scanning spectrometer operating software ► Advanced, computer-controlled, electro-mechanical material handling and sorting equipment ► Detects gamma-emitting radionuclides as the soil on the belt moves past the active area of the detector ► 100% assay of processed materials by laboratory quality gamma spectroscopy analysis 6

Orion ScanSort SM Configuration 7

ScanSort SM Display 8

Unconditional Clearance Levels (UCL) Average activity Radionuclides concentration in Bq/gram of Interest (Bq/g) Co60 0.1 Sr90 1 Cs137 0.1 Eu154 0.1 Pu238 0.1 Pu239 0.1 Pu240 0.1 Pu241 10 Am241 0.1 9

Radionuclide Ratios Radionuclides % of Total Activity of Interest Add a coloured transparent Cs137 48.8 segment and caption if Sr/Y90 31.1 required. Pu241 13.8 Am241 3.6 Pu239+240 2.2 Pu238 0.34 Eu154 0.15 Co60 0.03 10

UCL Sum-of-Ratios (SOR) Total Relative Net Isotopic Contribution to Activity (to Cs137) Activity UCL SOR Radionuclides of Add a coloured (%) Activity (Bq/g) (net activity/ UCL) Interest (ROI) UCL (Bq/g) transparent Cs137 48.8 1.00 0.08 0.1 0.800 segment and Sr/Y90 31.1 0.64 0.05 1 0.051 caption if required. Pu241 13.8 0.28 0.02 10 0.002 Am241 3.6 0.07 0.01 0.1 0.059 Pu239+240 2.2 0.05 0.00 0.1 0.036 Pu238 0.34 0.01 0.00 0.1 0.006 Eu154 0.15 0.00 0.00 0.1 0.002 Co60 0.03 0.00 0.00 0.1 0.000 UCL Sum Of Ratios 0.957 11

Project Overview Mobilized to Whiteshell site in April 2013 ► Started sorting soil in early May ► Rapidly warming spring weather caused early thawing of soils, resulting in material handling issues due to high clay content ► Demobilized staff, leaving equipment at site ► Remobilized January 2014 to work through winter when soil was frozen 12

“Manitoba Gumbo” Add a coloured transparent segment and caption if required. 13

Material Handling Issues with Clay Add a coloured transparent segment and caption if required. 14

Frozen on Remobilization -43C !!! Add a coloured transparent segment and caption if required. 15

Orion ScanSort SM System Add a coloured transparent segment and caption if required. 16

Orion ScanSort SM System Add a coloured transparent segment and caption if required. 17

Results ► ScanSort SM Results ► Over 2,300 metric tons of Cesium Pond material processed ► Over 163 metric tons of SMAGS material processed ► More than 65,000 measurements collected & processed ► Typical process rate of 50-100 tons/hour ► Cesium Pond Material ► Vast majority of material above UCL ► 100% assay of waste material for SMAGS waste acceptance criteria (WAC) ► SMAGS Building Material ► 35% below UCL so suitable for beneficial reuse ► 100% assay for waste characterization for SMAGS WAC 18

Lessons Learned ► Material Followability ► Material needs to be flowable, smaller sized material is better ► Frozen, conditioned material flows well, “Manitoba Gumbo” does not ► Stock Piling In Advanced Is Advised ► Survey production rate is dependent on material conditioning and feed rate to the system ► Condition material prior to stock piling ► Severe Weather Conditions ► Electronics don’t like -45 o C (neither do I) ► System enclosure/tent is very helpful to combat weather 19

Lessons Learned ► Equipment Contamination ► Surprisingly, not an issue. Self-cleaning? Send “clean material” through at end of survey to clean ► Minimal spread of contamination (control the dust, control the contamination) ► Survey Results (and Other) Reporting Criteria ► Educate the customer on what ScanSort SM can and can’t do ► Identify up-front what the survey results should look like and agree on them ► Get your customer involved early (and often) ► Be Flexible ► Have a backup plan ready (low feed rate, support equipment failure, weather issues, regulatory delays, etc.) 20

Q&A 21