© 2016 ARCADISMay 1, 20231

UNDERSTANDING TENORM-RELATED CHALLENGES ASSOCIATED WITH MICHIGAN

BASIN HYDROCARBON PRODUCTION

Donald J. Carpenter, PG, CPGDecember 1, 2016

© 2016 ARCADISMay 1, 20232 © 2016 ARCADISMay 1, 20232

A Systematic Overview will aid in Understanding TENORM-Related Issues

© 2016 ARCADISMay 1, 20233

Technologically Enhanced Naturally Occurring

Radioactive Material is One of Five Radioactive

Wastes Regulated in

the US

High Level Radioactive Wastes1

Uranium Milling Residues2

“Transuranic Wastes” having an atomic number greater than 92 (Uranium) 3

Technology Enhanced Naturally Occurring Radioactive Material (TENORM) or accelerator produced materials- Dominantly regulated at the State Level

4

Low Level Radioactive Waste 5

Definition of Radioactive Wastes Within the United States

© 2016 ARCADISMay 1, 20234

TENORM Can Pose Important Worker Safety and Material Handling and Disposal Issues

May be an unexpected and disruptive finding

Increasing worker-related litigation

Increasing regulatory scrutiny

Serious implications related to improper disposal attempts

© 2016 ARCADISMay 1, 20235

Aluminum Processing WasteCoal and Coal Ash WasteConsumer ProductsCopper Processing WasteDrinking Water Treatment WasteFertilizer WasteGeothermal WasteGold and Silver Processing WasteOil and Gas Processing WasteRare Earth Processing WasteTin Processing WasteTitanium Processing WasteWastewater Processing WasteZircon Processing Waste

Approximately 100 tons of scale per oil well is generated annually in

the United States.

The average radium concentration in scale is estimated at 480 pCi/g

Additional information may be found at the U. S. EPA TENORM website

Oil and Gas Processing Waste is Only One of the Types of TENORM Recognized by the EPA

© 2016 ARCADISMay 1, 20236

TENORM Related to Oil And Gas Production has been Known for Decades

TENORM is found in oilfield hydrocarbons 1904TENORM-bearing scale and sludges in pipes and production equipment1951

Millions of barrels of petroleum-related TENORM awaiting disposal

150,000 barrels being generated per year

American Petroleum Institute suggests that 1/3 of all producing U.S. oil and gas wells have elevated radiation

© 2016 ARCADISMay 1, 20237

Radioactive Radium, Radon, and Lead are all Generated from Uranium

Present in Host RockUnique Geochemical Behavior of each Radionuclide must be considered

Two different forms of TENORM can be generated:1) Radium-enriched Barium Sulfate

scale2) Lead-210 formed from Radon-222

present in natural gas

Important

GammaEmitters

© 2016 ARCADISMay 1, 20238

Radium Isotopes are also Produced within the Thorium-232

Decay Chain

Important

GammaEmitters

• Separation by geochemical processes of the thorium parent from the radium daughters results in rapid deletion due to their short half-lives

• Only about 6% of initial Ra-228 remains after about 25 years (4 half-lives)

• Ra-228 typically not a concern at legacy operations, but may be detectable in “new” material

Gamma measured at landfills

© 2016 ARCADISMay 1, 20239

Predictable Manner of Nuclear Decay Provides Insight as to Radionuclide Composition with Time

Combined with Specialty Geochemical Modeling can Help Predict Formation of TENORM Scale

Rate of Formation of Radium from Known Activity of Uranium

Rate of Formation of Radon from Known Activity of Radium

Rate of Formation of Lead from Known Activity of Radon

U-238 → Ra-226 → Rn-222 → Pb-210

© 2016 ARCADISMay 1, 202310 © 2016 ARCADISMay 1, 202310

The low levels of radium present though preclude the direct precipitation of radium sulfate or formation of a coherent scale layer

Demonstrate co-precipitation of radium with alkaline earth metals (barium) is dominant TENORM formation process

Radium can Precipitate as a Discrete Sulfate Mineral

Ra+2 + SO4-2 → RaSO4

© 2016 ARCADISMay 1, 202311

Precipitation of Alkaline Earth Sulfates can Co-Precipitate Radium

Ba+2 + SO4-2 → BaSO4

Ba+2 + (Ra+2) + SO4-2 → Ba(Ra)SO4

Acid InsolubleReadily Pass TCLP for BariumPhysically Resistant ScaleDense – Hard to Physically Wash OutDominantly Physical versus Chemical Dispersal - caveat forthcoming

Addition of Barium Chloride [BaCl2] (a soluble form of barium) and Sodium Sulfate [Na2SO4] results in the removal of dissolved radium from solution – Proven wastewater treatment process

© 2016 ARCADISMay 1, 202312

The Geochemical Behavior of Uranium can help Explain its Potential Separation from Radium

2 4 6 8 10 12 14

–.5

0

.5

1

pH

Eh

(vol

ts)

UO2++

UO2(CO3)2--

UO2(CO3)3----

UO2CO3

Uraninite

25°C

JGillow Fri Jun 15 2007

Dia

gram

UO

2++,

T

= 2

5 °C

, P

=

1.0

13 b

ars

, a

[mai

n]

=

10–5

.066

, a

[H

2O

] =

1

, a

[H

CO

3- ] =

10

–3;

Sup

pres

sed:

U3O

8(c,

alph

),

U4O

9(c)

• U+4 Oxidation state (Uraninite [UO2]) is stable under low Eh conditions (sulfides)

• UO2+2 oxidation state is stable

under high Eh conditions (sulfate)

• Uranium may be oxidized and transported away from radium which is immobile as a sulfate

• Radium may be mobilized in sulfate deficient conditions

UO2 and H2S or HS-

© 2016 ARCADISMay 1, 202313

Radium Accumulation Potential is a Function of Only a few Factors that can be Readily Modeled

These factors can be readily modeled, yielding an estimate of Radium-226-related TENORM production

Hot (deep) – High Salt (brine) Content – High FlowUse of Specialty Pitzer-based Thermodynamic Database and Solution

Equilibria Modeling

Uranium Activity within Producing Formation

Radium Transfer Efficiency to Brines

Geothermal Gradient and Depth of Producing

Formation

Concentration of Chlorides (Brine

Composition)Total Flow Rate

© 2016 ARCADISMay 1, 202314

Assess effects of:• Cooling• Sulfide oxidation

(formation of new sulfate ion)

• Mixing of multiple solutions

• Reactions with surface soils and sediments

• Changing geochemical conditions

• Precipitation of alkaline earth (barium) sulfates Benefit in proactively understanding likely areas of TENORM

and insight into its radioactivity and optimizing its deposition

Geochemical Modeling can Identify Locations and Conditions

Leading to TENORM Formation

© 2016 ARCADISMay 1, 202315

Removal of Sulfate Ion can Lead to Dissolution of Sulfate Minerals and Release of Radium

Bacterial Reduction of Sulfate Ion Under Reducing Conditions can Modestly Destabilize Barite or Other Sulfate Minerals

SO4-2 + 2CH2O ► H2S + HCO3

- Ba(Ra)SO4 + 2CH2O ► Ba+2 + Ra+2 + H2S + HCO3-

© 2016 ARCADISMay 1, 202316

How can I have Radioactive Material in my Natural Gas Plant?

© 2016 ARCADISMay 1, 202317

Hydrocarbon and Produced FluidsRadium-226 → Radon-222

Natural Gas StreamCH4

CH4 CH4

CO2

CH4

CH4

C2H6C3H8H2S

Rn-222 Rn-222

Rn-222

CH4

CH4 CH4

CO2

CH4

CH4

C2H6C3H8H2S

Rn-222 Rn-222

Rn-222

Lead-210 TENORM Results from Onward Processing of Produced Fluid and Co-Associated Natural Gas

© 2016 ARCADISMay 1, 202318

Radioactive Decay of Radon Results in Radioactive Lead Production and the “Other TENORM”

Radon-222 → Lead-210

CH4

CH4 CH4

CO2

CH4

CH4

C2H6C3H8H2S

Rn-222

Natural Gas Stream

Rn-222Rn-222

Pb-210Pb-210

Gas stream-entrained Lead-210 particles are now available for deposition within the processing facility

© 2016 ARCADISMay 1, 202319 © 2016 ARCADISMay 1, 202319

Radon Activity is Highly Concentrated Into Propane Phase During Gas Fraction Separation

Methane "Other Gasses" Propane0%

10%

20%

30%

40%

50%

60%

70%

80%

90% 37 pCi/L – Rn-222

1,165 pCi/L – Rn-222

Up to a 75% Transfer Efficiency

Lead-210 will tend to be concentrated in propane processing portion of plant

Composition of a Typical Natural Gas (by Volume)

© 2016 ARCADISMay 1, 202320

Lead-210 Accumulation Rate is Function of Only a few Factors

Radon Concentration in Natural Gas

Deposition Efficiency

Total Flow Rate

Duration Available for Rn-222 Decay

Calculations suggested Radon-222 activity within natural gas of about 24 pCi/Liter

© 2016 ARCADISMay 1, 202321

The Comparatively Long Half-life of Lead-210 also Allows for its Persistence After Plant Shutdown

0 22 45 67 89 112 134 156 178 2010

10

20

30

40

50

60

70

80

90

100

Pb-210

Years

Percent Initial Activity Plot of Lead-210 Decay

© 2016 ARCADISMay 1, 202322

Lead-210 And Polonium-210 Typically Form a Thin Coating on Pipes and Other Internal Surfaces

Shiny internal surface – may or may not be readily apparent

Typically only Internal surfaces

Implications as to worker health and material disposal

© 2016 ARCADISMay 1, 202323

Highest Lead-210 and Polonium-210 Activities Often Associated with Grease and Rubber Products

© 2016 ARCADISMay 1, 202324

Lead-210/Grease/Rubber Relationship may be due to Proven Radon-222 Concentration In Organics Leveraged in radio analytical methods Liquid

Scintillation Cocktails (toluene) Ostwald solubility coefficient - 30 to 50 times

greater in organics than in water Radon-222 concentrates in grease/rubber then

decays into Lead-210 Lead-210 metal particles may also physically

adhere to grease surface Rubber may develop static electrical charge

helping to attract lead grains No adverse neutron generation due to

Polonium-210 alpha emission interaction with lithium within grease

© 2016 ARCADISMay 1, 202325

Radiological Threats are Increased when Internal Surfaces are Exposed

Steel pipe attenuates alpha and beta radiation

Potential for Bremsstrahlung radiation from Bismuth-210

Worker safety issues increase from exposing internal surfaces• Cutting of pipes• Dismantlement or disassembly• Subsequent handling

Generation of airborne Lead-210 and Polonium-210 bearing particulates, radioactive metal fume, and aerosols

© 2016 ARCADISMay 1, 202326

It is Not the “Presence” of Lead-210 That is Problematic, it is its “Unexpected” Presence

Adverse worker exposure

Halting of scheduled work

Potentially problematic disposal

Significant cost and scheduling-related impactsWith proactive identification Lead-210 simply becomes another “special waste” issue to be addressed during the course of the project

© 2016 ARCADISMay 1, 202327

Competing Characteristics of the Michigan Basin Moderate TENORM Generation Potential

• Evaporites present throughout Devonian and Silurian strata – Highly elevated brine concentration enhances barium solubility

• Comparatively low geothermal gradient ~10°C per kilometer (average 22°C per kilometer) – cooler brine temperatures decrease barium solubility

• Comparatively shallow production – contrast to Texas or Louisiana

© 2016 ARCADISMay 1, 202328

Breadth of Michigan Basin Hydrocarbon Production will have Spectrum of TENORM Challenges

• Deeper oil production with warm and highly saline brines – visible scale formation – legacy operations

• Long term gas production from deeper, saline horizons although less impacted by geology

• Flow rate and duration of operation

• Gas Processing with propane or propylene production

© 2016 ARCADISMay 1, 202329

Michigan is One of 18 States to Specifically Regulate TENORM

As expected regulations varying significantly by State, both by isotope and by associated activities

Important to differentiate “remediation” with “disposal” criteria

Remediation Goal (plus background)

5 pCi/g Radium-22615 pCi/g Radium-22615 pCi/g Radium-22615 pCi/g Radium-22615 pCi/g Radium-226

15 centimeter lifts

© 2016 ARCADISMay 1, 202330

Landfill Waste Acceptance Criteria for TENORM Disposal is Comparatively Higher In Michigan

• Michigan standard – 50 pCi/g Radium-226• Lead-210 is not explicitly regulated• Established to help minimize disposal costs• Higher activities may be disposed by deep well injection

- (Approved by State or EPA)• Many states’ disposal criteria range from 5 to 30 pCi/g Radium-226

• May include Radium-228, Uranium-238, Thorium-232, Lead-210• Varying degrees of radiological sophistication of various state

regulators• Regulations may pertain to medical-related radiopharmaceuticals

© 2016 ARCADISMay 1, 202331

A Comparatively Limited Suite of Disposal Options is Available for more Elevated Activity TENORM

© 2016 ARCADISMay 1, 202332

Careful Coordination

with Landfills is Recommended

Whenever Disposing of

TENORM

Although exempt K-40 and certain Th-232 decay chain products all have gamma emissions

Portal monitors set to trigger alarm at very low activities (1.5 to 2 times background)

In event of alarm, you are “presumed guilty until proven to be slightly less guilty”

May not be aware of the materials that are acceptable

“Fear Factor” in terms of disposing of unacceptable material

Communication and “education” in terms of waste acceptance criteria

© 2016 ARCADISMay 1, 202333

A Systematic Overview will aid in Understanding TENORM-Related IssuesTechnology Enhanced Naturally Occurring Radioactive Material is One of Five Radioactive Wastes Regulated in the US

TENORM can Pose Important Worker Safety and Material Handling and Disposal Issues

Radium Accumulation Potential is a Function of Only a Few Factors that can be Readily Modeled

It is not the “Presence” of Lead-210 that is Problematic, it is its “Unexpected” Presence

Careful Coordination with Landfills is Recommended Whenever Disposing of TENORM

© 2016 ARCADISMay 1, 202334

Thank you!

c 810 224 2159e donald.carpenter@arcadis.coma 28550 Cabot Drive

Suite 500Novi, MI 48377

DONALD J. CARPENTERSenior Vice President & Chief Geochemist

Registered and Certified Professional GeologistAIPG, AK, IN, PA, WIConnect with me on LinkedInFollow me on Twitter @DonCarpenter14

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