ML11214A196
| ML11214A196 | |
| Person / Time | |
|---|---|
| Site: | West Valley Demonstration Project, P00M-032 |
| Issue date: | 02/27/2011 |
| From: | Chamberlain J West Valley Environmental Services |
| To: | NRC/FSME |
| References | |
| Download: ML11214A196 (18) | |
Text
West Valley Demonstration Project West Valley Demonstration Project West Valley Environmental Services y
j West Valley Environmental Services y
j Services Services Design and Installation of a Design and Installation of a Permeable Treatment Wall Permeable Treatment Wall Design and Installation of a Design and Installation of a Permeable Treatment Wall Permeable Treatment Wall Permeable Treatment Wall Permeable Treatment Wall to Mitigate Expansion of to Mitigate Expansion of Permeable Treatment Wall Permeable Treatment Wall to Mitigate Expansion of to Mitigate Expansion of Strontium Strontium--90 Contaminated 90 Contaminated Groundwater Groundwater Strontium Strontium--90 Contaminated 90 Contaminated Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater John Chamberlain Sr Technical Advisor
_1 WMS 2011, Feb 27 - Mar 3 11138_1
Project Partners Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_2 WMS 2011, Feb 27 - Mar 3
Site Background
~3,330-acre New York State-owned site located ~35 miles south of Buffalo Si f
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Site of only commercial used (spent) nuclear fuel reprocessing facility to operate (1966-72) in the United States DOE assumed control f d l
d ti of developed portion of site (~160 acres) in 1982 to solidify the high-level waste high level waste generated from reprocessing and decommission facilities used Site is a small plateau with streams on th id Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_3 WMS 2011, Feb 27 - Mar 3 three sides WVDP premises (~160 acres) marked by white line
Reference:
WMS 2010 Paper 10409
Strontium-90 Groundwater Plume
Groundwater containing Sr-90 identified in northeast (NE) section of site (1993)
Relatively permeable glacial sediment 4-30 feet-thick overlies very low permeability clay till G
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Groundwater in northern portion of site moves NE and surfaces in ditches or as seeps at edge of plateau
Investigation indicated that Sr-90 came N
Investigation indicated that Sr 90 came from process line leak(s) during reprocessing (1966-72)
Two actions taken to slow plume expansion Pump and treat wells installed at one location (< 30 feet apart) in 1995 Pilot PTW (~ 30 feet wide) in 1999 Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_4 WMS 2011, Feb 27 - Mar 3
Reference:
WMS 2010 Paper 10409
Plume Mitigation Approach Selected 2006-07 Plan to address site Plan to address site decommissioning in stages (phases) was developed p
Placement of full-scale PTW was proposed to control plumes leading edge while Clay (till) edge while decommissioning progresses 2008-2009 2008 2009 Characterization of leading edge of plume confirmed viability of a Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_5 WMS 2011, Feb 27 - Mar 3 y
full-scale PTW
Design Relied on Data from Pilot PTW Pilot PTW installed 1999 Performance was limited Performance was limited Zeolite used removed Sr-90 Limited groundwater flow through; most groundwater bypassed pilot PTW PTW Evaluation completed 2002 identified key factors S
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l Pilot PTW installation Scale: size relative to plume important Depth: assure PTW is keyed into clay Trench walls: must be permeable Zeolite: chemical composition and physical strength must resist compaction Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_6 WMS 2011, Feb 27 - Mar 3 Pilot PTW monitoring wells
Projecting PTW Longevity Goal: Control expansion of leading Analyte Units Mean Calcium
µg/L 166,820 Potassium
µg/L 3 028 p
g edge of plume for up to 20 years Sr-90 removal Potassium
µg/L 3,028 Magnesium
µg/L 26,203 Sodium
µg/L 184,733 dependent on Zeolite cation exchange capacity Groundwater cation content Strontium-88
µg/L 327 Sr-90 concentration in groundwater Volume of groundwater that passes through PTW thickness is only factor that can be adjusted to enhance longevity Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_7 WMS 2011, Feb 27 - Mar 3 longevity
Testing Addresses Uncertainties Zeolite Lab testing (2 zeolites)
Lab testing (2 zeolites)
Column tests for cation exchange capacity (over a year)
- Standardized synthetic water with Sr-88 (University at Buffalo, UB)
(University at Buffalo, UB)
- Actual site groundwater with Sr-90 (WVDP)
Field testing
- Checked for possible breakdown due to shipping, equipment handling installation equipment handling, installation Selected material from Bear River Mine in Preston, ID
- Higher clinoptilolite content No measurable clay content Columns in UB lab
- No measurable clay content
- No observed breakdown due to shipping, equipment handling, installation Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_8 WMS 2011, Feb 27 - Mar 3 Pre-shipment testing
Addressing Uncertainties (cont)
Trencher Focused on use of one pass trencher to minimize "smearing" on trench Focused on use of one-pass trencher to minimize smearing on trench walls Surveyed suppliers and found one with trencher capable of installing PTW Conducted three trencher tests Conducted three trencher tests over a year to check:
- Trencher assembly and general operation Zeolite handling and
- Zeolite handling and placement
- Soil management
- Decontamination Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_9 WMS 2011, Feb 27 - Mar 3 Trencher
Initial Trencher Test Trencher Trench Box Cutting Teeth T
hi Test Trench Trenching Trenching Test Trench Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_10 WMS 2011, Feb 27 - Mar 3
Trencher Findings and Adjustments Stone slinger and bag cutter for zeolite loading Conveyor for excavated soil
Developed system to add water to zeolite in the trench box to counteract groundwater pressure in the trench System to add water to zeolite Stone slinger and bag cutter for zeolite loading y
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Tested and adopted use of stone slinger to feed zeolite to the trencher
Developed lifting bar for zeolite bags and bag cutters to place on stone slingers Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_11 WMS 2011, Feb 27 - Mar 3
Developed conveyor to directly collect excavated soil and place it in an above-ground containment structure
PTW Installation Area Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_12 WMS 2011, Feb 27 - Mar 3
Final Design Aerial View Aerial View 39 b i
39 borings placed to confirm depth to till Cross Section Cross Section p
Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_13 WMS 2011, Feb 27 - Mar 3
InstallationOct 17 - Nov 18, 2010 Soil Structure Soil PTW Platform Access Road Structure Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_14 WMS 2011, Feb 27 - Mar 3 October 17 November 6
Installation (cont)
Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_15 WMS 2011, Feb 27 - Mar 3 November 1. 2010
Addressed Field Conditions Internal belts in conveyer replaced and strengthened after cobble sized stones Soil containment reinforced to ensure containment of wetter after cobble-sized stones were encountered Resolved containment of wetter-than-expected soil Resolved Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_16 WMS 2011, Feb 27 - Mar 3 Conveyor rebuilt and containment re-enforced in parallel; 12 days
Installation (cont)
November 5 November 5 Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_17 WMS 2011, Feb 27 - Mar 3 November 18 November 21
PTW - February 6, 2011 Nov 30 Trenching equipment off site Dec 27 Completed installation of 66 monitoring wells Jan 27 Jan 27 Initial sampling round completed 860 long, 19-30 deep, 39 wide 2,377 tons of zeolite installed
~ 45 trencher hours of operation Design and Installation of PTW to Mitigate Sr-90 Contaminated Groundwater 11138_18 WMS 2011, Feb 27 - Mar 3 completed 45 trencher hours of operation