National Analytical Management Program (NAMP)

U.S. Department of Energy Carlsbad Field Office

In Cooperation with our University Partners

Radiochemistry Webinars Environmental/Bioassay Radiochemistry Series

Unconventional Drilling/Hydraulic Fracturing and

Natural Radioactivity

Meet the Presenters… Michael K. Schultz, PhD

Dr. Schultz is an Associate Professor in the Department of Radiology at the University of Iowa, with secondary appointments in the Free Radical and Radiation Biology; Human Toxicology; and Medical Scientist Training Programs. Dr Schultz also co-directs the Radiochemistry Program in the Department of Chemistry. His research interests in environmental radioactivity focus on naturally occurring radioactive material (NORM) associated with liquid and solid waste resulting from unconventional drilling and hydraulic fracturing. This year, Dr. Schultz has been invited to speak on this topic at the American Chemical Society National Meeting, the National Environmental Monitoring Conference, and ASTM International. A recent article (Nelson et al., Env Sci Techn Let, March 11, 2014) was selected for an ACS Editor’s Choice Award and the article, first authored by PhD graduate student and Presidential Fellow Andrew Nelson, is featured on the cover of the journal. Funded by the University of Iowa’s Center for Health Effects of Environmental Contaminants, Dr. Schultz's laboratory (with collaborator Tori Forbes, Department of Chemistry) has begun field studies on the environmental geochemical behavior of NORM in natural surface water systems impacted by unconventional drilling and hydraulic fracturing operations and waste treatment facilities. Mike earned his PhD in Oceanography at Florida State University, studying the environmental radiochemistry of anthropogenic and natural radionuclides in terrestrial and aquatic systems.

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Andy Nelson, MS Andy Nelson earned a B.A. in biochemistry from the University of Colorado in 2009 and an M.S. in environmental engineering from the Colorado School of Mines in 2010. As a research assistant in the Department of Molecular, Cellular, and Developmental Biology (MCDB) at the University of Colorado, Mr. Nelson studied free radical signaling mechanisms relevant in aging and tumor progression. In 2012, Andy was awarded the University of Iowa Presidential Graduate Fellowship to pursue a PhD in the Interdisciplinary Human Toxicology Program. He is currently a doctoral candidate under the mentorship of Dr. Schultz, with whom he studies radioactivity associated with unconventional drilling (hydraulic fracturing and horizontal drilling) of shale gas. Much of Mr. Nelson’s work to date has focused on developing methods that are suitable for monitoring levels of naturally occurring radioactive materials (NORM) present in wastes generated by unconventional natural gas exploration. Andy’s research has helped develop partitioning models that will be used in the development of sound waste management strategies for solid and liquid wastes generated by unconventional drilling.

Radioactivity and Unconventional

Drilling Michael K. Schultz, PhD Andrew W. Nelson, MS

National Analytical Management Program (NAMP)

U.S. Department of Energy Carlsbad Field Office

TRAINING AND EDUCATION SUBCOMMITTEE

Disclaimer

Certain products and manufacturers are mentioned during this presentation for the purpose of fostering understanding.

Reference to these commercial products and manufacturers in this presentation does not constitute recommendation or endorsement of the products.

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Radiochemistry

Unconventional Drilling Hydraulic Fracturing

Outline

• Background on “fracking”? – Why, Where, What and How

• Source of radioactivity

• Geochemical considerations

• Methods to detect NORM in flowback

• Considerations for: – Liquid waste – Solid waste

• Future research needs

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Increasing Global Energy Demand

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http://www.eia.gov

Unconventional Drilling Rapidly Expanding in U.S.

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http://www.eia.gov

Major U.S. Natural Gas Plays

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http://www.eia.gov

Global Shale Formations

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http://www.eia.gov

What is Fracking?

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“Fracking” =

Hydraulic Fracturing ≈

Unconventional Drilling

5 Major Stages of Hydraulic Fracturing

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http://www2.epa.gov/hfstudy/hydraulic-fracturing-water-cycle

Stage 1: Water Acquisition

• Water Usage – Up to 55,000 m3 (15 million

gallons) per well

• Concern – Straining water resources

• Arid states concerned • Growing concern elsewhere

– Unknown contribution to radioactivity • Recycling fluids?

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Stage 2: Chemical Mixing

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• Caustics and toxics –Hydrochloric acid –Proprietary chemicals –Antimicrobials –Unknown interactions with NORM

• Sand –Crystalline silica –OSHA hazard alert –Mined in IA, WI

https://www.osha.gov/dts/hazardalerts/hydraulic_frac_hazard_alert.html

Stage 3: Well Injection

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https://www.osha.gov/dts/hazardalerts/hydraulic_frac_hazard_alert.html

Radioactive Solid Waste 16

• Bit Cuttings

– 250,000 kg/well

– Trucks turned away from landfills

– Radiation alarms set off

https://www.rigzone.com/training/insight.asp?insight_id=294&c_id=24

http://www.post-gazette.com/local/marcellusshale/2013/08/22/Marcellus-Shale-waste-trips-more-radioactivity-alarms-than-other-products-left-at-landfills/stories/201308220367

Stage 4: Flowback/Produced Water 17

Thousands of cubic meters (millions of gallons) produced fluids per well

Radioactive Produced Fluids

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• Documented High Levels of Ra

> 670 Bq/L 226Ra

(18,000 pCi/L)

> 95 Bq/L 228Ra

(2,500 pCi/L)

Stage 5: Disposal/Treatment of Waste 19

• Solids (250000 kg/well) – Municipal landfills • Radiation alarms

– Hazardous waste landfills

• Fluids – POTWs – Industrial treatment

facilities – Deep surface injection – Recycling – Transportation

considerations • Trucking • Barges?

Where does the radioactivity come from?

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1. Radioactive Tracers – Most common are gamma emitters • 46Sc, 140La, 56Mn, 24Na, 124Sb, 192Ir, 99Tcm, 131I, 110Agm, 41Ar, 133Xe

– Measure flow rates & inter well connections – Short half-lives (hours to days)

2. Naturally Occurring Radioactive Materials – Present in the formation • 238U (uranium) series • 232Th (thorium) series • 235U (actinium) series

– Long half-lives, decay products, differing chemistries

http://www-pub.iaea.org/MTCD/publications/PDF/Pub1171_web.pdf

Marine Black Shales

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http://pubs.usgs.gov/pp/0356c/report.pdf

http://written-in-stone-seen-through-my-lens.blogspot.com/2011/01/lace-crab.html

• Ancient marine environments

• High organic matter

• High associated U levels

General Shale Geochemical Characteristics 22

• Reducing environment (anoxic)

• Microbial sulfate reduction

– Low sulfate concentrations

• High salt

– Evaporite

– Unclear where all the salt from Marcellus originates

General Chemistry of Uranium Series

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http://metadata.berkeley.edu/nuclear-forensics/Decay%20Chains.html

• U redox sensitive (+6 soluble, +4 immobile)

• Pa particle reactive

• Th particle reactive

• Ra soluble in low-sulfate (SO42-) brine

• Rn short-lived gas

• Po isotopes short-lived, redox sensitive, particle reactive

• Bi isotopes short-lived, supported by Pb isotopes

• Pb isotopes short-lived (exception 210Pb, which can accumulate in brine)

Case Study — Marcellus Shale

• One of the largest natural gas plays in the U.S.

• Underlies multiple states

• Regulation differs state to state

– NY “fracking’ moratorium

– OH, WV, PA allow

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http://www.marcellus.psu.edu/

http://www.eia.gov/todayinenergy/detail.cfm?id=14091

NORM in the Marcellus Shale

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http://www.eia.gov/todayinenergy/detail.cfm?id=14091

• Marine Black Shale

• Devonian Age

– 350-400 million yrs old

• Radioactive decay products assumed in secular equilibrium

Lessons from NORM Analysis of Marcellus Flowback

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Matrix

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Ba:Ra ≈ 109

Analyte Concentration (mg/L)

Chloride 146,667

Strontium 36,333

Sodium 29,333

Calcium 13,000

Barium 9,000

Magnesium 853

Manganese 3

Iron 43

Total Solids 277,666

Suspended Solids 783

Scheme for Analysis

Gamma Emitters: 228Ac, 226Ra, 224Ra, Pb and Bi isotopes, 235U, 208Tl, 234Th

Special Case:

226Ra, 222Rn

Alpha Emitters (excluding Ra): Po Isotopes, U isotopes, 228Th, 230Th, 232Th

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Liquid Scintillation

Alpha Spec

HPGe Gamma Spec

Rad7

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BaSO4 MnO2

610 B

q/L

670 B

q/L

Wet Chemical Methods

Not Effective

Analysis of Alpha Emitters

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• Isotope dilution alpha spectrometry

– U

– Th

– Po

• Wet chemistry effective

– Pre-concentrations (ex: MnO2, FeOH3)

– Chromatography (ex: Eichrom® Resins)

– Microprecipitations (ex: CeOH3)

Simplifying the Matrix (MnO2)

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0.25 – 1L FBW

Precipitate Chromatography

Complex

Digest Wash/Dissolve

Add Tracers Add KMnO4

Method Summary

• Polonium Recoveries (81 ± 9 %)

Autodeposition slow

Considered alternatives

• Uranium Recoveries (63 ± 8 %)

• Thorium – Recoveries (85 ± 9 %)

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Ingrowth of 210Pb and 210Po in Flowback

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*H. Bateman, Proc. Cambridge Philos. Soc. 1910 (15) 423-427

Uranium—Low Levels in Flowback

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*[226Ra= 670 Bq/L]

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Ingrowing 228Th in Flowback

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Partitioning Model

Th-234

U-238

Daughter recoil

U(IV)-234

Th-230 Ac-228 Th-228

Ra-224

Daughter recoil Insoluble

Thorium Series

Uranium Series

Brine

Rock

Rock

Th-232

Pb-210

Fissure

U-234

Ra-226

Rn-222

Rn-222

Po-210 ?

Ra-228

Th-234

U-238

Daughter recoil

U(IV)-234

Th-230

Ra-226

Ac-228 Th-228

Ra-224

Daughter recoil Insoluble

Thorium Series

Uranium Series

Brine

Rock

Rock

Th-232

Pb-210

Fissure

Rn-222

Po-210

Rn-222

U-234

Ra-228

The Big Picture 37

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Importance of Partitioning Decay Product Ingrowth in Flowback

*closed system

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Ingrowth Occurs for Many Years

Special Considerations for Liquid Waste

• Enriched in Ra isotopes – Can lead to Ra contamination

• Rn generators – Inhalation hazards?

• Ra decay products ingrowth unavoidable

• Ra decay products have different chemistry – Ra treatments (ex: sulfate

precipitations) • May not remove decay products • 210Pb, 210Po, and 228Th of concern • Difficult to detect

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Liquid Waste in Marcellus Region

• Industrial Treatment

– Occurs in PA, WV, OH

– Ra decay products

– Occupational exposure?

– Surface Water Contamination?

• Underground Injection & Recycling Flowback

– Ra decay products

– Occupation exposure?

– Unclear fate of NORM after injection

onlinelibrary.wiley.com/doi/10.1002/wrcr.20096/pdf

Special Considerations with Solid Waste

• Bit cuttings coming from reduced environment to oxidizing surface –Increase mobility of select

radionuclides • U4+

U6+ • Po speciation? • Fe and Mn adsorptive surfaces may

change

• 234U, 210Po, 232Th, 230Th, 228Th not detected by gamma-ray meters –Note: 234U enriched by

alpha-recoil, thus cannot assume 1:1 234U:238U activity

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http://www.theguardian.com/environment/2011/jun/27/water-shortages-threaten-renewable-energy

• Billions of kgs bit cuttings

• Interstate transfer

• Most bit cuttings go to landfills

• Emerging reports of radioactivity alarms at landfills

– Unclear which isotopes

– Unclear what level of alpha emissions

• Concerns of radioactivity leaching

Solid Waste in Marcellus Region

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http://www.triplepundit.com/2014/04/west-virginia-landfill-wastewater-shows-elevated-radioactivity-due-fracking-authorities-report/

Future Research Needs

On-going studies in the Schultz and Forbes Labs:

Other important questions:

• Bench studies on the behavior of NORM in bit cuttings from Marcellus Shale

• Field studies on the environmental fate and equilibrium status of Ra decay products

• What levels of 222Rn are released from landfills and wastewater treatment facilities accepting unconventional drilling waste?

• What is the potential/extent of bioaccumulation of NORM from unconventional drilling waste?

Thank you! Questions? • State Hygienic Laboratory at UIowa

– Dr. Michael Wichman – Marinea Mehrhoff – Dustin May

• Schultz and Forbes Labs (UIowa) – Dr. Michael K Schultz – Dr. Tori Z Forbes – Eric Eitrheim – Andrew Knight

• EMS – Robert Shannon – Dr. Robert Litman

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Upcoming NAMP Radiochemistry

Webinars

• Introduction to the Fuel Cycle – June 26, 2014

• Front End: Uranium Mining, Milling, Enrichment and UO2 Production – July 24, 2014

• Environmental and human contamination in the Front End of the Fuel Cycle for Uranium Mining and Milling – August 21, 2014

Visit the NAMP website at www.wipp.energy.gov/namp