K.P. Smith, R.L. Johnson, and J. Quinn Environmental Assessment Division

1. Streamlined Approaches to Characterizing NORM-Contaminated Sites Can Translate into Significant Cost Savings K.P. Smith, R.L. Johnson, and J. Quinn Environmental Assessment Division Argonne National Laboratory

2. Sampling Programs Are Key Components of All Environmental Restoration Processes Multiple steps in a restoration project involve environmental sampling and analysis: • Preliminary site assessment • Extended site investigation • Corrective action study • Remedial action • Closure Traditional sampling and analysis programs are expensive and time-consuming.

3. Approach • Real-timesample analysis • Rapid on-site decision making SampleCollection # 1 1 5 1 2 0 9 9 • Advantages • Reduce cost/sample • Reduce # of samples • Reduce # of events • Better characterization • Allows in situ soil segregation • Requirements • Field analytical method • Decision support on site Sample Analysis Decision Making Adaptive Sampling and Analysis Programs (ASAP) Can Cut Costs Significantly

4. Assemble Baseline Information • Base maps • Geological information • Existing sampling data Make Qualitative Decisions about Data Management • Make Quantitative Decisions On Site • Extent of contamination • Where to stop • When to stop ASAP Decision Support Has Three Distinct Phases • Data integration • Data visualization • Data dissemination

5. Oil and gas production and processing activities can cause NORM to accumulate above natural background levels. Radionuclides: Ra-226, Ra-228, and their decay products Waste streams: produced water, scale, sludge, equipment, surface soils Can ASAP Efficiencies Be Realized at a NORM Site?

6. NORM Cleanup Requirements in the U.S. Typical NORM cleanup criteria: • Ranges from 5 to 30 pCi/g (0.185 to 1.1 Bq/g) Ra-226 or Ra-228 above background • Sometimes two different limits based on radon emanation rate • Averaged over 100 m2

7. 1.4-hectare pipe handling facility • NORM contamination in surficial soils: Ra-226 activity levels into the tens of thousands of pCi/g • About 27 m3 of soil previously excavated and drummed based on gross activity screens • State guidelines require remediation to 5 pCi/g (0.185 Bq/g) averaged over 100 m2 NORM Case Study: Michigan Site

8. Large number of field screening, direct measurement, and field analytical methods: • Combined walkover/GPS systems for gross activity • Stationary in situ NaI instruments • Stationary in situ HPGe measurements • Mobile laboratories with gamma spectroscopy capabilities The ASAP Approach Is Ideal for NORM-Contaminated Soils

9. Sodium Iodide (Na I) sensor  measures total activity • High detection efficiency, low energy resolution • Collects data at 2 second intervals, generating hundreds to thousands of data points per acre • Inexpensive: pennies per data point • Combined with differential GPS systems to visualize walkover results Gamma Walkover Surveys Provide Inexpensive, Comprehensive, Qualitative Information

10. RadInSoilTM provides Ra-226 concentrations (pCi/g) for surface soils based on 5–10 min. readings • Instrument needs to be calibrated to background at the site and assumes no other decay chain exists above background • Requires little training to operate • Per measurement costs on the order of $10–20 per data point Direct NaI Measurements Can Provide Estimates of Ra-226 Concentrations

11. In situ High Purity Germanium (HPGe) gamma spectroscopy provides accurate, isotope-specific concentrations for surface soils • Low detection efficiency, high energy resolution • Concentrations hold for the “field of view” of the instrument • Requires trained operator • Costs are on the order of $100 per measurement In Situ HPGe Measurements Provide Accurate, Isotope-Specific Concentrations

12. Decisions are binary — either cleanup soil or leave behind • Want to identify “trigger” levels that can be used to carve up the site based on gross activity information • Use paired information to do the analysis • Makes use of nonparametric approach with no assumptions about linear correlation Relationships between Gross Activity and Cleanup Criteria Are Key

13. Step 1: Complete Gamma Walkover Step 2: Develop Relationship between Gamma Walkover Data and Cleanup Criteria • Paired gross activity to RadInSoil measurements collected at 49 sites • Established trigger levels for 5-pCi/g cleanup criterion: 1,800–2,500 cpm ASAP Process for Michigan Site

14. Step 3: Divide Site on Basis of Trigger Levels • Three areas: likely clean, likely contaminated, and uncertain based on available data • Average data over 100 m2 using moving window averages on gamma walkover data ASAP Process for Michigan Site

15. Step 4: Remediate and Rewalk • Verification of “uncertain” areas with in situ HPGe • Selective removal of “hot” spots across site • Rewalk with gamma walkover surveys and reshoot with HPGe to confirm clean Note: The site was not cleaned up to background but was brought into compliance with state guidelines: 5 pCi/g Ra-226 averaged over 100 m2. ASAP Process for Michigan Site

16. Significant analytical cost savings  about a 90% savings using in situ analytical capabilities • Compressed time line because remediation was integrated with characterization The Michigan Case Had Positive Results • Reduced disposal costs  possibly as much as $36,000 less • Excellent agreement between off-site confirmatory sample results and on-site analytics

17. For more information: • Final report available from: • Download in PDF format from “www.ead.anl.gov” • More information available from: • Bob Johnson • rljohnson@anl.gov • 630-252-7004 • Karen P. Smith • smithk@anl.gov • 303-986-1140, ext. 267 Consistent with Triad approach being recommended by the USEPA: www.triadcentral.org