Development of Rapid 

Radiochemical Method for Gross 

Alpha and Gross Beta Activity 

Concentration in Flowback and 

Produced Waters from Hydraulic 

Fracturing Operations 

This report was prepared for the National Analytical Radiation Environmental Laboratory of the Office of 

Radiation and Indoor Air and the National Exposure Research Center of the Office of Research and 

Development, United States Environmental Protection Agency. It was prepared by Environmental 

Management Support, Inc., of Silver Spring, Maryland, under contract EP-W-07-037, work assignment 2-

43, and EP-W-13-016, task order 014, both managed by Dan Askren. This document has been reviewed in 

accordance with U.S. Environmental Protection Agency (EPA) policy and approved for publication. Note 

that approval does not signify that the contents necessarily reflect the views of the Agency. Mention of trade 

names, products, or services does not convey EPA approval, endorsement, or recommendation. 

R E S E A R C H A N D D E V E L O P M E N T
 

EPA/600/R-14/107 

July 2014 

Validation of Rapid Radiochemical 

Method for Gross Alpha and Gross Beta 

Activity Concentration in Flowback and 

Produced Waters from Hydraulic 

Fracturing Operations 

Brian Schumacher 

U.S. Environmental Protection Agency 

Office of Research and Development 

National Exposure Research Center 

Environmental Sciences Division 

Las Vegas, NV 89119 

John Griggs and Dan Askren 

Office of Air and Radiation 

Office of Radiation and Indoor Air 

National Analytical Radiation Environmental Laboratory 

Montgomery, AL 36115 

Bob Litman and Bob Shannon 

Environmental Management Systems 

Silver Spring, MD 20910 

Marinea Mehrhoff, Andrew Nelson, and Michael K. Schultz 

University of Iowa 

Iowa City, Iowa 52242 

U.S. Environmental Protection Agency 

Office of Research and Development 

Washington, DC 20460 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

CONTENTS 

Acronyms, Abbreviations, Units, and Symbols ............................................................................ vii

Radiometric and General Unit Conversions .................................................................................. ix

1.0 

3.0 

Introduction..........................................................................................................................1

2.0 

4.0 

Characterization of the Sample Matrix ................................................................................5

Initial Radioanalytical Methods...........................................................................................9

Method Development Process Summary ...........................................................................11

5.0 Participating Laboratories..................................................................................................13

6.0 Measurement Quality Objectives .......................................................................................13

7.0 Method Development Plan ................................................................................................17

7.1 Method Uncertainty ................................................................................................. 17

7.2 Detection Capability ................................................................................................ 19

7.3 9

7.4 

Method Bias ............................................................................................................. 1

Analyte Concentration Range .................................................................................. 21

7.5 Method Specificity ................................................................................................... 21

21

8.0

7.6 Method Ruggedness ................................................................................................. 

	 Techniques Used to Evaluate the Measurement Quality Objectives for Methods 

Development Project ..........................................................................................................23

8.1 Required Method Uncertainty ................................................................................. 23

8.2 Required Minimum Detectable Concentration ........................................................ 23

9.0 Evaluation of Experimental Results ...................................................................................25

9.1 Summary of the Method .......................................................................................... 25

9.2 Required Method Uncertainty ................................................................................. 25

9.3 Required Minimum Detectable Concentration ........................................................ 31

Evaluation of the Absolute and Relative Bias 

11.0

9.4 ......................................................... 36

9.5 Method Ruggedness ................................................................................................. 38

10.0	 Timeline to Complete a Batch of Samples ........................................................................39

	 Reported Modifications During Development and Recommendations for Future 

Work ..................................................................................................................................41

12.0

13.0

	 Summary and Conclusions ................................................................................................47

	 References..........................................................................................................................49

Attachment I: Method Development Trials .................................................................................51

Attachment II: Time Lapse ...........................................................................................................59

July - 2014 i 
July - 2014 ii	 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Attachment III: Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity 

in Flowback and Produced Waters from Hydraulic Fracturing Operations 

(FPWHFO) ........................................................................................................61 
July - 2014 iii 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Figures 

Figure 1 – Po-209 Alpha Spectrum .............................................................................................. 52

 

 

Figure 2 – Alpha Spectrum of Separated 230Th............................................................................ 53

Figure 3 – Liquid scintillation Spectrum of 209Po ........................................................................ 55 

Figure 4 – Flow Chart for Method Development Using Tracers ................................................. 56 

Figure 5 – Elution Profile for Traced solution with 0.1 M Ammonium Bioxalate 

in 4 M HCl .................................................................................................................. 56 

Figure 6 – Total Recovery of Tracers (%) with (0.1 M Ammonium Bioxalate in 

4 M HCl)......................................................................................................................57 
July - 2014 iv 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Tables 

Table 1 – Non-Radiological Analysis of FPWHFO and Surrogate Sample ................................ 6 

Table 2 – MQOs Targeted for Gross Alpha and Gross Beta in FPWHFO ............................... 15 

Table 3 – Method Development As-Spiked Concentrations, MQOs and Mean 

Measured Results....................................................................................................... 16 

Table 4 – Proposed Sample Processing and Counting Combinations ....................................... 17

18 

 

Table 5 – Actual Sample Concentrations Used for MD Process ............................................... 

Table 6A – Th, U. Po Gross Alpha by LSC - Analytical Results for Required Method 

Uncertainty Evaluation.............................................................................................. 27 

Table 6B – 226Ra Alpha by Gamma Spectrometry - Analytical Results for Required 

Method Uncertainty Evaluation ................................................................................ 28

y Gamm

 

Table 6C – 228Ra Beta b a Spectrometry - Analytical Results for Required 

Method Uncertainty Evaluation ................................................................................ 29 

Table 7A – Th, U, Po Gross Alpha by LSC - Experimental Standard Deviation of the 

Seven PT Samples by Test Level (230Th) .................................................................. 30 

Table 7B – 226Ra Alpha by Gamma Spectrometry - Experimental Standard Deviation 

of the Seven PT Samples by Test Level .................................................................... 30 

Table 7C – 228Ra Beta by Gamma Spectrometry - Experimental Standard Deviation 

of the Seven PT Samples by Test Level .................................................................... 31 

Table 8A – Th, U, Po Gross Alpha by LSC - Blank Water Samples ........................................... 31

ter Samples ..................................... 32

226

 

Table 8B – Th, U, Po Gross Alpha by LSC - Surrogate Wa 

Table 8C – Ra Alpha by Gamma Spectrometry in Demineralized and Surrogate 

Water Samples ........................................................................................................... 32

Table 8D – 228Ra Gross Beta by Gamma Spectrometry in Demineralized and Surrogate 

Water Samples ........................................................................................................... 33

Table 9A – Reported Results for Samples Containing Th, U, Po Gross Alpha by LSC 

at the As-Tested MDC Value (12.45 pCi/L) ............................................................. 34

MDC Value (55.2 pCi/L) .......................................................................................... 35

 

Table 9B – Reported Results for 226Ra Alpha by Gamma Spectrometry at the As-Tested 

 

Table 9C – Reported Results for 228Ra Beta by Gamma Spectrometry at the As-Tested 

MDC Value (30.4 pCi/L) .......................................................................................... 36 

Table 10 – Absolute and Relative Bias for Gross Alpha and Gross Beta by the Three 

Measurements ............................................................................................................ 37 

Table 11 – Estimated Elapsed Times for Gross Alpha Analysis ................................................. 59 

Table 12 – Estimated Elapsed Times for Gross Beta Analysis ................................................... 59 

July - 2014 v 
July- 2014 vi 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Acronyms, Abbreviations, Units, and Symbols 

AAL ...............analytical action level 

ACS ................American Chemical Society 

APS ................analytical protocol specification 

Bq ...................becquerel 

CLNC ...............critical net concentration 

CSU ................combined standard uncertainty 

Ci ....................curie 

d......................day 

EPA ................U.S. Environmental Protection Agency 

ESD ................Environmental Sciences Division 

FPWHFO... ...Flowback and Produced Waters from Hydraulic Fracturing Operations 

g......................gram 

GPC ................gas-flow proportional counter 

h......................hour 

ID ...................[identifier] [identification number] 

L .....................liter 

LCS ................laboratory control sample 

LSC ................liquid scintillation [count] [cocktail] 

m ....................meter 

M .................... [molar] 

MARLAP .......Multi-Agency Radiological Laboratory Analytical Protocols Manual 

MD.................method development 

MDA ..............minimum detectable activity 

MDC ..............minimum detectable concentration 

MDRM...........method development reference material

min .................minute 

MQO ..............measurement quality objective 

MVG ..............Method Validation Guide for Qualifying Methods Used by Radiological 

Laboratories Participating in Incident Response Activities 

NAREL ..........EPA’s National Analytical Radiation Environmental Laboratory, 

Montgomery, AL 

July - 2014 vii 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

NERC .............National Exposure Research Center 

NHSRC ..........EPA’s National Homeland Security Research Center, Cincinnati, OH 

NIST ...............National Institute of Standards and Technology 

ORD ...............U.S. EPA Office of Research and Development 

ORIA ..............U.S. EPA Office of Indoor Air and Radiation 

φMR........................... required relative method uncertainty 

PT ...................proficiency testing 

QA ..................quality assurance 

QAPP .............quality assurance project plan 

QC ..................quality control 

STS .................sample test source 

uMR ..................required method uncertainty 

y......................year 

July - 2014 viii 
July - 2014 ix 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Radiometric and General Unit Conversions 

To Convert To Multiply by To Convert To Multiply by 

years (y) 

seconds (s) 

minutes (min) 

hours (h) 

days (d) 

3.16×107 

5.26×105 

8.77×103 

3.65×102 

s 

min 

h 

d 

Y 

3.17×10–8 

1.90×10–6 

1.14×10–4 

2.74×10–3 

disintegrations per second (dps) becquerels (Bq) 1 Bq dps 1 

Bq 

Bq/kg 

Bq/m3 

Bq/m3 

picocuries (pCi) 

pCi/g 

pCi/L 

Bq/L 

27.0 

2.70×10–2 

2.70×10–2 

10–3 

pCi 

pCi/g 

pCi/L 

Bq/L 

Bq 

Bq/kg 

Bq/m3 

Bq/m3 

3.70×10–2 

37.0 

37.0 

103 

microcuries per milliliter 

(μCi/mL) pCi/L 109 pCi/L μCi/mL 10–9 

disintegrations per minute (dpm) μCi 

pCi 

4.50×10–7 

4.50×10–1 pCi dpm 2.22 

cubic feet (ft3

) cubic meters (m3) 2.83×10–2 m3 ft3 35.3 

gallons (gal) liters (L) 3.78 L gal 0.264 

gray (Gy) Rad 102 rad Gy 10–2 

roentgen 

equivalent man (rem) sievert (Sv) 10–2 Sv rem 102 

NOTE: Traditional units are used throughout this document instead of the International System of Units (SI). Conversion to SI 

units will be aided by the unit conversions in this table. 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

July - 2014 x 
July - 2014 xi 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Acknowledgments 

This method development report was developed by the National Analytical Radiation 

Environmental Laboratory (NAREL) of the Environmental Protection Agency’s (EPA) Office of 

Radiation and Indoor Air (ORIA) in cooperation with the Environmental Sciences Division of 

the National Exposure Research Center (ESD NERL). Dr. John Griggs was the project lead for 

this document. Several individuals provided valuable support and input to this document 

throughout its development. Special acknowledgment and appreciation are extended to Dr. Brian 

Schumacher of ESD NERL. We also wish to acknowledge Ms. Marinea Mehrhoff (State 

Hygienic Laboratory at the University of Iowa) and Dr. Michael Schultz and Mr. Andrew Nelson 

(University of Iowa), who conducted the method development studies. Numerous other individuals, 

both inside and outside of EPA, provided comments and criticisms of this method, and their 

suggestions contributed greatly to the quality, consistency, and usefulness of the final method. 

Technical support was provided by Environmental Management Support, Inc. 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

July - 2014 xii 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

1.0 Introduction 

This report summarizes the development and testing of an improved method for the 

Determination of Gross Alpha and Gross Beta Activity in Flowback and Produced Waters from 

Hydraulic Fracturing Operations (FPWHFO). Flowback and produced waters are characterized 

by high concentrations and complex mixtures of inorganic salts, organic compounds and other 

materials. They may commonly contain concentrations of naturally-occurring radionuclides from 

the uranium and thorium decay chains as high as 103–104 times the level of activity routinely 

observed in environmental water samples. The complex nature and high concentration of matrix 

constituents in these water samples present significant technical challenges especially for gross 

alpha and gross beta determinations in such samples. 

It is critical when working with gross alpha and gross beta measurements that one 

understand what the screening results represent. These measurements are not nearly as simple as 

many people may believe. There is a relatively a short list of natural chain radionuclides. 

Uranium and thorium chain radioactivity (i.e., 238U and 232Th, and progeny), and 40K, usually 

account for >95% of the naturally occurring alpha and beta activity. A relatively small amount of 

actinium (Ac) chain activity may also be present (less than 5% of total activity is associated with 

the Ac chain, i.e., 235U and its decay progeny). Thus, five radioelements in the sample either 

directly comprise or indirectly support the naturally occurring activity of the sample: 

uranium 234 • (238U; 235U; U);

232 230 228 23 • thorium ( Th; Th; Th; 4

Th and its short-lived decay progeny 234mPa)

• radium

228Ra and its 228

o short-lived decay progeny Ac; 

226 222

o Ra and its short-lived decay progeny Rn, 218Po, 214Pb, 214Bi, 214Po;

224

o Ra and its short-lived decay progeny 220Rn, 216Po, 212Pb, 212Bi, 212Po, 208Tl;

• lead (

210Pb and its short-lived decay progeny 210Bi; and

• polonium (210Po).

Method 900.0 is the benchmark method for gross alpha and gross beta determinations. 

Method 900.0 involves evaporating the sample to a thin layer of solid residue in a stainless-steel 

planchet and analyzing alpha and beta particles emitted from the source using gas-flow 

proportional counting. The benefit of this method is its rapidity and relatively low-cost in 

comparison to performing radionuclide specific testing. This method focuses heavily on 

identifying 226Ra, with a secondary concern on natural uranium and thorium chain activity. This 

method will identify some non-volatile man-made radionuclides that are present as 

environmental contaminants. 

Method 900.0 has several notable limitations that impact the reliability and 

intercomparability of gross alpha and beta measurements, especially for naturally occurring 

radioactivity. The method under-responds to low-energy beta emitters such as 210Pb and 228Ra. 

Lax control of the timing of the count relative to preparation and collection of the sample may 

cause the method to dramatically over-respond, or to completely fail to detect radionuclides 

July - 2014 1 
 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

present at the point of collection. For example, the gross alpha activity of samples containing 

226Ra will increase following the preparation with the count stabilizing at 400% of the actual 

226Ra activity 3–4 weeks after preparation.1

 In contrast, delaying the analysis of the sample for 

more than two weeks after collection will lead to a failure to detect 224Ra or its decay progeny 

that were present at the time of collection. Finally, the method is not applicable for the 

determination of analytes that are volatile under the conditions of analysis. This would 

potentially impact 210Po. 

Finally, Method 900.0 is designed for low-solids samples such as drinking water. This 

is because alpha and beta particles are severely attenuated by matter they encounter as they travel 

to the detector (including “self-absorption” by the solids in the sample test source). The amount 

of solids in a sample limits the size of sample that can be processed and thereby the sensitivity of 

the measurement. Method 900.0 restricts residue thickness for gross alpha measurements to a 

maximum of 5 mg/cm2

. In a 50-mm diameter stainless-steel planchet, this is equivalent to 100 

milligrams of solid residue. While this method is applicable to drinking water samples which 

generally have solids content under 500 mg/L, FPWHFO samples may have solids content in the 

hundreds of thousands of mg/L and sample sizes would be restricted to a small fraction of a 

milliliter. Since the sensitivity of the measurement is inversely proportional to the size of sample 

processed, the capability of the method to detect activity could be decreased by a factor of a onethousand and the ability of the evaporation approach to detect radioactivity in FPWHFO 

becomes questionable at best. 

One approach to addressing this limitation would involve using a measurement 

technique that is not sensitive to the solids content of the sample being analyzed. Gamma 

spectrometry, for example, is capable of determining isotope specific gamma-ray emissions from 

samples of 3 - 5 kg or larger. Unfortunately, this technique is not as sensitive as techniques such 

gas-flow proportional counting (GPC) or liquid scintillation counting (LSC). Gamma 

spectrometry cannot detect pure alpha and beta emitters, of which there are several of concern 

for FPWHFO samples. Liquid scintillation spectrometry is a technique that is capable of 

sensitive measurements of alpha and beta particle emissions and can tolerate somewhat larger 

amounts of solids (up to about 1⁄2 gram in the sample test source) than can GPC. 

A second approach can be taken to improve the sensitivity of gross alpha and gross beta 

measurements. This involves developing chemical separation methods to remove non-radioactive 

constituents from the sample thereby allowing the radioactive constituents to be concentrated 

into a source that can be measured using a method sensitive to alpha and beta particle emissions 

(e.g., gas-flow-proportional counting or liquid scintillation spectrometry). Method 900.0 relies 

on evaporation to accomplish this. Water, which is not in itself radioactive, is removed from the 

sample by evaporation. For this reason, Method 900.0 is limited to determining non-volatile 

constituents in samples.2 

1

 This is due to ingrowth of short-lived alpha-emitting decay progeny 222Rn, 218Po, and 214Po. Similar effects are noted with betaemitting decay progeny of 226Ra, 224Ra, 238U, and 210Pb with time frames ranging from days to months. 

2

 This raises questions about whether Po can be reliably determined using method 900.0. 

July - 2014 2 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

As a result of these considerations, method development efforts in Phase 1 of this 

project focused on exploring: 

•	 Detection methods that are less subject to self-absorption (e.g., gamma spectrometry or

liquid scintillation), and if possible, less sensitive to differences in the energy of the

decay particle;

•	 The viability of using chemical separation methods that selectively isolate longer-lived

radionuclides of concern from non-radioactive constituents that may be present in high

enough concentrations to limit sample size (i.e., U, Th, Ra, Pb, and Po need to be

separated from Ca, Sr, Ba, Mg, Na, K, Fe); and

•	 Preparation methods that are less subject to losses due to analyte volatility.

•	 Developing and validating a method that could rapidly achieve detection limits in the

range of those recognized for gross alpha and gross beta in drinking water.

Since each FPWHF sample matrix is different, it is important to initially characterize 

whether or not U/Th isotopes may be present prior to validating any method. This will ensure 

that necessary chemistry is addressed for each radionuclide. 

Another important aspect of gross alpha and gross beta determinations needs to be 

considered. As mentioned above, the time elapsed between collection of the sample and the 

sample preparation, and the time between the preparation of the sample and the count, 

significantly impact the final result. While it is not practicable to simulate this during the development

process, the theoretical impact of decay and ingrowth is well established and should 

be addressed in the scope and applicability and interferences statements when a laboratory 

adopts this method and validates it in their method format. Failure to delineate these concerns 

may result in a failure of users to recognize that results may vary by a factor of two or more, and 

that delay in analysis may result in complete failure of the method to detect short-lived 

radionuclides such as 224Ra, present in significant quantities at the time of sample collection. 

July - 2014 3 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

July - 2014 4 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

2.0 Characterization of the Sample Matrix 

Per instruction by the Environmental Protection Agency (EPA), the method 

development and testing targeted a single FPWHFO sample from the Marcellus shale region 

of Pennsylvania. A 55-gallon drum of the water was received at the National Analytical and 

Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama in late April, 2013. At 

the beginning of May 2013, it was then transferred to the State Hygienic Laboratory at the 

University of Iowa for method development and testing studies. 

The sample was described by the Iowa laboratory as a clear, light amber liquid, of high 

specific gravity (~1.25 g/cc) with less than ~0.5% by volume (by visual inspection) of a light, 

suspended reddish-brown precipitate. The sample was not preserved prior to receipt at the 

laboratory. After the sample arrived at the laboratory, the drum was mixed to ensure 

homogeneity and two carboys of the water withdrawn. No sample filtering or preservation was 

performed. 

Preliminary analytical work was performed to characterize the major non-radiological 

(i.e., chemical) composition of the water. These analyses provided perspective on the matrix so 

that one could assess how best to configure a method as well as to help understand difficulties 

encountered while developing the method. The data were also used to create a surrogate sample 

for the method development process whose composition was very similar to that of the sample. The 

chemical analyses of the field sample and the surrogate solutions are shown in Table 1. 

July - 2014 5 
 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 1 – Non-Radiological Analysis of FPWHFO and Surrogate Sample 

Analyte 

Concentration 

(mg/L) 

Field Sample 

LOD [1] 

(mg/L) 

Concentration 

in Surrogate 

(mg/L) 

LOD [1] 

(mg/L) Method 

Chloride (Cl–) 147,000±6,000 1 100,000 1 Chloride, EPA 300.0 

Strontium (Sr) 36,000±2,000 200 34,000 0.10 Metals, EPA 200.7 

Sodium (Na) 29,000±1,000 5,000 30,000 2.5 Metals, EPA 200.7 

Calcium (Ca) 13,000±1,000 10,000 12,000 5.0 Metals, EPA 200.7 

Barium (Ba) 9,000±400 500 8,500 0.25 Metals, EPA 200.7 

Magnesium (Mg) 850±40 120 850 2.5 Metals, EPA 200.7 

Potassium (K) 160±10 2.5 160 5.0 Metals, EPA 200.7 

Manganese (Mn) 3.4±0.2 1 — — Metals, EPA 200.7 

Iron (Fe) 43±2 5 23 0.10 Metals, EPA 200.7 

Lead (Pb) 1.0±0.1 0.5 — — Metals, EPA 200.7 

Aluminum (Al) LOD 5 — — Metals, EPA 200.7 

Fluoride (F–

) LOD 0.1 — — Fluoride, SM 4500-F C 18th 

2– Sulfate (SO4 ) LOD 40 — — Sulfate, EPA 300.0

Nitrate nitrogen as 

N (NO3 

-

) LOD 10 — — Anions, EPA 300.0 

Nitrite nitrogen as 

N (NO2 

–

) LOD 5 — — Anions, EPA 300.0 

Ortho-phosphate 

as P (PO4 

3−

) 8±1 0.02 — — ortho-Phosphate as P, LAC 10-115-01-1A 

Alkalinity 10 1 — — Alkalinity as CaCO3, 

SM 2320 B 18th 

Bicarbonate 

alkalinity (HCO3 

–

) 10 1 — — Alkalinity as CaCO3, SM 2320 B 18th 

Carbonate 2– alkalinity (CO3 ) LOD 1 — — Alkalinity as CaCO3, SM 

2320 B 18th 

Silicon (Si) 3.7±0.3 2.5 — — Silicon, EPA 200.7 

Total Solids (TS) 278,000±6,000 1 — — Total Solids (Dried at 

103°C), SM 2540 B 18th 

Total Suspended 

Solids (TSS) 780 1 — — 

Total Suspended Solids 

(Dried at 103 °C) USGS 

1-3765-85 

Total Extractable 

Hydrocarbons 

(TEH)[2] 

2.3±0.1 0.1 — — Total Extractable 

Hydrocarbons, Iowa OA-2 

[1]	 LOD – Limit of Detection at 99% confidence determined per 40 CFR Part 136, Appendix B Definition and Procedure for the Determination 

of the Method Detection Limit (MDL). 

[2]	 Chromatographic patterns do not conform to fuel standards for this range. 

July - 2014 6 
 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

A radiological characterization of the water was also conducted during the preliminary 

phase to determine the radionuclides present in the sample. Gamma spectrometric analysis of 

raw FPW showed high levels of activity for the 226Ra sub-chain of 238U with a 226Ra 

concentration of 17,600 ± 1,400 pCi/L (k=1). Significantly elevated activity of 228Ra (1,950 ± 

110 pCi/L) was also noted with no indication of significant levels of 224Ra which may be present 

in freshly collected samples containing 228Ra. This indicates that activity concentrations of 228Th 

were likely low and that the sample had probably aged enough that 224Ra and 212Pb had decayed 

prior to receipt at the laboratory (longer than one month). The activity concentrations of 238U 

(

234Th, and 234mPa), and 235U were not detectable using gamma spectrometry.3

 Thus, it is possible 

to make theoretical conclusions about the state of equilibrium at the time of sampling. Since the 

gross radioactivity of naturally-occurring decay chains changes with time, control of time 

elapsed between sampling and preparation of the sample, and the preparation and analysis will 

be factors that will significantly impact gross alpha and gross beta measurements and which will 

need to be closely controlled. 

Based on the elevated levels of radioactivity in the sample received, it became apparent 

that a method development reference material (MDRM) would need to be created that closely 

matched the composition of the FPWHFO but did not contain significant concentrations of 

naturally occurring radionuclides. In previous method development studies of matrices such as air 

filters and soil, low concentrations of naturally occurring radionuclides were present that could 

easily be accounted for when creating test samples of low activity. However with the high 

concentrations of the naturally occurring radionuclides in this sample, an effective measure of 

uncertainty at low activities, or of a minimum detectable concentration (MDC), would not be 

possible. 

Reproducing the predominant non-radioactive constituents in the sample, Cl, Ca, Ba, 

Sr, Mg, Na, K, and total solids in the test samples was critical both for the method development 

and testing process. Based on the non-radiological analysis of the sample, a “surrogate” 

method development reference material (MDRM) solution composition was formulated. It was 

evident from some of the first attempts at gross radioactivity analysis that minimum detectable 

concentrations would be much higher than that for drinking water. 

The elevated concentrations of solids in the sample meant ordering very large quantities 

of the soluble salts needed to make the surrogate used to prepare development process blank, MDC 

and spiked samples. 

The extremely high levels most particularly of Ca, Sr, and Ba, all Group II chemical 

analogues for Ra, placed into question the initially proposed analytical approach and required 

significant modification of the techniques used. While the procurement of salts was in process, 

laboratory staff attempted several gross separation and analysis processes (noted below) on the 

real sample to see how they would fare as preparation for the method development process. 

3

 Informal alpha spectrometry results obtained from personnel working with NAREL staff in May 2013 indicated that no 238U or 234U was detected in the sample at the 0.1 pCi/L level. 

July - 2014 7 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Once created, the surrogate matrix was spiked with 226Ra, 230Th and 228Ra based on the 

magnitude of blank analyses to create MDRMs at three levels for testing of the required 

method uncertainty and one MDRM for verification of the required minimum detectable 

concentration. The radionuclides for spiking differed from the outline in the method development

plan. 

July - 2014 8 
 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

3.0 Initial Radioanalytical Methods 

A series of different approaches were explored for the gross alpha and gross beta 

analysis to identify an approach optimized to accommodate the matrix of the FPWHFO sample 

received from the EPA. While the testing matrix used was quite challenging, these results 

may or may not be applicable to matrices that differ from this sample matrix. Approaches 

explored ranged from tests of EPA Method 900.0 through attempts to explore different detection 

techniques, to approaches to separate/concentrate radioactive constituents of the sample. Several 

examples include: 

•	 The Method 900.0 approach failed to produce a usable test source with an extremely

small 0.1 mL aliquant.

•	 Direct addition of the sample to liquid scintillation cocktail resulted in precipitation of

matrix components and failure to produce a useable test source.

•	 Gamma spectrometry analysis provided results for a number of the natural emitters in the

sample. This approach to quantitation is not based on measurement of alpha emissions,

but the results are radionuclide specific and can be used to calculate the total gross alpha

activity associated with a radionuclide such as 226Ra in a sample when it is in secular

equilibrium4

 with its progeny (that are gamma emitters).

Attachment I provides additional details on these and other attempts to processing the 

FPWHFO sample, as well as testing if the relative robustness of several techniques for chemical 

separation of key radionuclides (Th, U, and Po). 

The goal of developing a rapid, and economically viable approach for isolating and 

analyzing alpha emitting radionuclides (Ra, Th, U and Po) in a single test source and 

determining gross alpha activity using a single sensitive measurement of alpha emissions, 

however, has yet to be realized. This is due to the complex matrix composition, and the levels of 

Group II elements (Mg, Ca, Sr, and Ba) in the FPWHFO matrix. Group II constituents were 

present in overwhelming amounts (gram/liter concentrations) in this sample. The chemical 

behavior of these elements closely mimics that of radium, which foiled all attempts to achieve a 

group separation of Ra, Th, U, and Po. 

As a result, the most viable approach for gross alpha analysis involved the use of two 

physical determinations of alpha activity. The first of these determinations involves a group 

separation of Th, U, and Po using a rapid solid-phase extraction chromatographic separation 

technique5

 followed by liquid scintillation analysis of alpha emissions. This technique is 

described in greater detail below. The other contributor to gross alpha, 226Ra (+progeny) is 

4

 If secular equilibrium is to be assumed steps need to be taken in a laboratory’s method that indicates how this will be 

controlled. If secular equilibrium cannot be assured then the measured values should be qualified noting that these activity 

concentrations maybe larger. 

5

 This involves the use of a commercial solid phase extraction resin such as EichromTM. This material has a very high selectivity 

coefficient for U, Th and Po (and other high atomic number radionuclides) over first second and third row transition series 

elements. 

July - 2014 9 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

determined by high purity germanium (HPGe) gamma spectrometric measurement of gamma 

emissions from the sample. 

Since the gamma spectrometric determination of 226Ra has very different levels of 

measurement uncertainty than does the liquid scintillation approach for thorium, uranium, and 

polonium, it was necessary to establish separate measurement quality objectives (MQOs) for 

required method uncertainty for each of the two analyses. The results of the analyses may be 

used separately as the individual results are quite informative about radioactivity in the sample, 

or the two results and their respective uncertainties mathematically combined to yield a single 

combined activity and standard uncertainty for gross alpha activity in the sample. 

Attempts to perform gross beta in a method along the lines of Method 900.0 also 

proved fruitless as extremely elevated solids in the sample produced unacceptably high-levels of 

self-attenuation or resulted in sample aliquants that were far too small to provide meaningful 

detection levels. Preparation of a reproducible test source proved to be unsuccessful due to nonuniform drying and spattering of sample solids. While a chemical separation of naturally 

occurring beta emitting members and progeny of the uranium and thorium decay chains may 

theoretically be possible, there would still be concern about significant differences in decay 

energy of the beta emitters that could negatively impact quantitation. Using gamma emissions 

from the radionuclides, however, permits use of a non-destructive method that avoids lengthy 

separations, and minimizes time performing the separations. The trade-off, however, is that the 

counting times for samples can be significant (6 hours or more) depending upon the gamma 

detector efficiency. 

While each gamma ray detected can be ascribed to a specific radionuclide and the 

activities of these radionuclides and their progeny are easily summed, an assessment of the total 

uncertainty can only account for the uncertainty of those beta-gamma emitters identified. It will 

not account for beta-gamma emitters present at low, sub-detectable levels. This is a more 

significant issue for low-activity samples where no gamma rays are detected. Based on the high 

activity of radium in this type of sample matrix, this seems to be a more remote possibility. 

July - 2014 10 
July - 2014 11	 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

4.0 Method Development Process Summary 

The method development (MD) plan for gross alpha and gross beta analysis of FPWHFO 

follows the guidance provided in Method Validation Guide for Qualifying Methods Used by 

Radiological Laboratories Participating in Incident Response Activities [MVG] (EPA 2009), 

Validation and Peer Review of U.S. Environmental Protection Agency Radiochemical Methods 

of Analysis (EPA 2006), and Chapter 6 of MARLAP (2004). This MD process was conducted 

under the generic Quality Assurance Project Plan Validation of Rapid Radiochemical Methods 

for Radionuclides Listed in EPA’s Standardized Analytical Methods (SAM) for Use During 

Homeland Security Events (EPA 2012). This method is considered a “first time approach.” 

Therefore, the method needed to be evaluated according to MARLAP method validation “Level 

D” or “Level E.” 

The proposed method, for both gross alpha and gross beta, in the MD plan was 

validated against acceptance criteria for the required method uncertainty about a specified 

analytical action level (AAL) concentration and at the required MDC. After several 

modifications to the MD plan, and due to significant challenges related to the matrix of the 

sample, the technique used for gross beta analysis was changed from the traditional screening 

using beta particle emission counting (gas-flow proportional counting or liquid scintillation 

counting) to an inferential gamma spectrometric analysis method. Since the gamma spectrometry 

allows the determination of several beta-gamma emitters, the overall relative required method 

uncertainty for beta-gamma emitters was expanded to 50% to accommodate the increased 

uncertainties of the multiple measurements needed. 

In addition to determination of the required method uncertainty and verification of the 

required minimum detectable concentration, analytical results were evaluated for statistical bias, 

absolute bias for blank samples and relative bias at each of the three test level radionuclide 

activities. The radiochemical yield of the method was also evaluated as a characteristic of 

method ruggedness. 

The method development process was divided into four phases as follows: 

1. Phase 1

a.	 Laboratory familiarization with the method concept.

b.	 Set-up of the laboratory and acquisition of reagents, standards and preparation of

in-house performance test (PT) samples.

c.	 Perform preliminary tests of the methods on an actual sample.

d.	 Make changes to improve the method based on the preliminary tests.

2. Phase 2

a.	 Conduct method testing for required method uncertainty using internal PT

samples.

3. Phase 3

a. Conduct verification of the required MDC using internal PT samples.
July - 2014 12 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

4. Phase 4

a. Report results.

b. Written report and narratives by laboratory describing the process/method.

c. Feedback comments on the method.

d. Method development report written by EMS and reviewed by laboratory.

The objective of Phase 1 was to have the laboratory become familiar with the draft 

method. While the laboratory obtained hands-on experience, areas of the method that required 

optimization were identified. Based on the information and experience gained during Phase 1 

runs, the analysis method was optimized and modified prior to initiating the formal testing

process in Phases 2 and 3. 

The draft method was run (see Attachment I for description of Radionuclide: 226Ra and 

Radionuclides: U, Th, and Po) with the field sample obtained from the EPA using the innate 

226Ra as a measure of the success of each purported separation step. The laboratory also prepared 

blank and spiked surrogate solutions (as described in the introduction above) to assess the 

feasibility of the draft method with elements representing the longer-lived U and Th decay chain 

radionuclides (i.e., 230Th, natural uranium, 209Po) since these radionuclides and their short-lived 

progeny comprise the alpha radioactivity of the sample. Sample test sources were prepared after 

the separation of the respective alpha emitters for alpha spectrometric analysis. The radionuclide 

specific testing also allowed assessment of the robustness of the method to recover the added 

radionuclides from the matrix. Attachment 1 presents data on the recovery of these 

radionuclides/radioelements. Due to the challenging matrix, quantitative recovery was neither 

expected nor was it achieved, but the final method was effective and obtained recoveries that 

approached 80–90% for the targeted analytes. As a gross screening method, this is deemed to be 

acceptable. 

The initial objective for detection levels was aimed at drinking water MPC 

concentrations. However, the difficulties encountered in this initial evaluation of the proposed 

methods with the matrix evoked a reevaluation of what could be the attainable action levels and 

detectability concentrations. The values that are found in Tables 2 and 3 were based on this 

reevaluation. 

During Phases 2 and 3 of the MD process, the laboratory analyzed in-house PT samples 

consisting of method development reference materials [MDRM] prepared from the surrogate 

solution (described in the introduction above) spiked with known amounts of 230Th, 226Ra and 

228Ra. The laboratory was instructed to spike the PT samples with concentrations consistent with 

test levels for the required method uncertainty and the required MDC. The targeted test levels 

and applicable MQOs for Phases 2 and 3 are listed in Table 2. 

Following completion of the method developkment studies, comments from the laboratories 

were evaluated per guidance in the MVG. The final method was finalized to conform to the 

documented “as-tested” conditions in Phases 2 and 3. The report was also edited to ensure clarity 

based on comments received from the laboratories. Thus, the test data presented in this report

reflect the final method included in the attachments to this document. 
July - 2014 13 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

5.0 Participating Laboratories 

The State Hygienic Laboratory and at the Radiology and Radiation Oncology Free 

Radical and Radiation Biology Program Laboratory, both at the University of Iowa, performed 

all of the analyses (radiological as well as non-radiological). 

6.0 Measurement Quality Objectives 

The gross alpha and gross beta analysis method was developed to meet MQOs 

established for the project. The MQOs selected include the radionuclide concentration range, the 

required method uncertainty at a specified radionuclide concentration (i.e., AAL), and the 

required MDC. Since the EPA did not provide regulatory action levels, MQOs were defined in 

the method development plan based on the presumed sensitivity of the techniques to be used. Once 

the sample was received and initial testing proved how challenging nature of the matrix would 

be, new technical approaches were needed and MQOs were updated to maintain consistency with 

the capabilities of the techniques being used. The AAL for 226Ra by gamma spectrometry is 

higher than initially envisioned while that for gross alpha by liquid scintillation is somewhat 

lower. Gross beta MQOs are based on gamma spectrometric analysis (see Attachment 1 

descriptions for not using traditional gross beta analysis) with separate MQOs for 228Ra (for 

gross beta analysis) and 226Ra (contribution to gross alpha and gross beta activity), based on the 

relative sensitivity for these radionuclides using gamma spectrometry. The targeted test levels 

and applicable MQOs for Phases 2 and 3 are listed in Table 2. 

The required method uncertainty for gross alpha (liquid scintillation count [LSC] 

contribution) assumes tolerable error rates of 10% (z1-α = z1-β = 1.282) for Type I and Type II 

errors. It is calculated for gross alpha using the following equation: 


	

௣஼௜ ሺ ି஽௅ሻ ሺଷ଴ିହሻ ݑ

 

 ௅ , ஼ௌ௅݄ܽ݌݈ܣ ݏݏ݋ݎܩ, ெோ

ൌ ൫௭భష

஺஺௅

ഀା௭భషഁ൯ ൌ ሺ ଵ.ଶ଼ଶ ା ଵ.ଶ଼ଶሻ 

 

ൌ 

ଶହ

ଶ.ହ଺ସ 

ൌ 9.8 pCi/L 

Where AAL is the analytical action level and DL is the discrimination level for gross 

alpha analysis. 

And the value for the relative required method uncertainty is: 

φMR, Gross AlphaLSC, = 100 × uMR / (AAL) = (9.8 / 30) = 33% 

The required method uncertainty for gross alph

as determined by the gamma spect

݄ܽ݌݈ܣ ݏݏ݋ݎܩ ,ெோ߮

a (gamma spec

௚௔௠௠௔ ௦௣௘௖௧௥௢௠௘௧௥௬ , ݑ

trometry contribution) is: 

rometry software algorithm. 

ெோ ൌ 33% 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

July - 2014 14	 

The potential contributors to the gross beta activity are 234Th, 234mPa, 214Pb, 214Bi, 212Pb,

212Bi, 208Tl, 228Ra, 228Ac, 210Pb, and 210Bi. 

Several of these are linked in shorter decay chains so contributions to the gross beta at 

full ingrowth can be calculated by measuring one of the radionuclides and assuming secular 

equilibrium with the others in the respective decay chain. These would be summarized as 

follows: 

234Th = 234mPa (full secular equilibrium within 10 minutes) 

214Pb = 214Bi (full secular equilibrium within 3 hours, Rn-222 is in secular equilibrium 

with Ra-226) 

212Pb = 212Bi = 208Tl / 0.36 (full secular equilibrium 72 hours after separation) 

228Ra = 228Ac (full secular equilibrium 36 hours) 

210Pb = 210Bi (full secular equilibrium 15–25 days after collection) 

Since only the non-bolded radionuclides are measured, the bolded radionuclides are 

determined inferentially. The activity and uncertainty of the measured values will be used as the 

values for the inferred radionuclides 234Th/ 234mPa, 214Pb/ 214Bi, 212Pb/ 212Bi/ 208Tl/, 228Ra/ 228Ac, 

and 210Pb/ 210Bi. 

The gross beta activity of samples is calculated based on the gamma spectrometric 

measurement of beta-gamma emitting radionuclides from the uranium and thorium chains that 

are present in detectable levels in the sample. The concentration of beta emitters that are detected 

may be calculated by inference when their gamma-emitting parents or progeny where these are 

present at detectable levels. Gamma emitting radionuclides are considered to be detectable when 

the relative combined standard uncertainty of the radionuclide is determined by the gamma 

spectrometry software to be less than or equal to 50%. The overall beta uncertainty is calculated 

as the quadratic sum of the uncertainties of the detected radionuclides contributing to the total 

gross beta activity.6 

Ra-228, based on the gamma emission of its short-lived progeny 228Ac, was chosen in 

lieu of other naturally occurring beta-gamma emitters to determine action levels and MDC for 

gross beta analysis. This choice is based on three factors: 

•	 The abundance of the 228Ac gamma ray at 911 keV is 25.8%. The abundance of the 214Bi

at 609 keV peak is 45.9% and that of 212Pb at 238 keV is 43.6%. 

•	 The efficiency of the 911 keV peak is lower than the other two gamma ray peaks.

•	 The abundance of 228Ra in many geologic formations used for oil and gas production is

much lower than that of Ra-226 or their respective progeny. 

This provides assurance that if the 228Ac action levels and MDC can be confirmed that those 

for the other principal naturally occurring beta-gamma chains can also be achieved. 

 

6

 The exception for this will be for 226Ra with a uMR = 9.8 pCi/L and a φMR = 33%. 
July - 2014 15	 

 

 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

The targeted required method uncertainty for each of the beta-gamma emitters that will be 

measured by gamma spectrometry is 50% at the AAL of 60 

Although the evaluation

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development of the gamma spectrom

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med with 

the 224Ra and 226Ra progeny fully ingrown to assess the achievable MDC and AALs. Table 2 also 

presents targeted values that will be evaluated once a gamma spectrometry method for a broader 

list of analytes has been fully developed. 

Table 2 – MQOs Targeted for Gross Alpha and Gross Beta in FPWHFO 

Measurement Matrix [1] AAL Required 

MDC/MDA[2] uMR 

[3] φMR 

[4] 

Gross Alpha pCi/L pCi/L pCi/L (%) 

230Th (liquid scintillation) FPWHFO 30 5 9.8 33% 

226Ra (based on the 186 keV 

gamma emission) FPWHFO 150 55 50 33% 

Gross Beta[4] 

228Ra (228Ac) FPWHFO 60 30 30 50%

Beta-emitting progeny of 226Ra 

(

214Pb/214Bi) and other gamma 

emitters in sample[5] 

FPWHFO -­ -­ -­ 50%

Beta-emitting progeny of 224Ra[5] 

(inferred based on gamma 

emissions of 212Pb) 

FPWHFO -­ -­ -­ 50%

Th-234[5] (and inferred 234mPa) FPWHFO -­ -­ -­ 50%

[1]	 A single sample of flowback and produced water supplied by EPA was used as the prototype for a surrogate matrix for method testing. 

The method development reference material (MDRM) consisted of aliquants of the surrogate matrix spiked with radionuclide solutions 

traceable to the National Institute of Standards and Technology (NIST). 

[2]	 The MDC represents the value for the individual measurement. A combined MDC for gross alpha or beta will not be determined due to 

significant differences in the sensitivity of the respective measurement techniques. 

[3]	 Required method uncertainty at and below the AAL. 

[4]	 Relative required method uncertainty above the AAL. 

[5]	 Preliminary development of the method for gross beta is based on measurement of 228Ac (gamma emitting decay progeny of 228Ra). Final testing

 will be conducted pending further refinement of the gamma spectrometry measurement technique. 

A synopsis of the final method testing results for all three test levels and the MDC is 

found in Table 3. The 230Th values represent the results by chemical separation and liquid 

scintillation counting. The results for 226Ra and 228Ra are from direct sample analysis by gamma 

ray spectrometry. 
 

 

 

 

 

 

 

 

 

July - 2014 16 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 3 – Method Development As-Spiked Concentrations, MQOs and Mean Measured Results 

Concentration 

Relative to 

Action Level 

Isotope 

Targeted 

PT 

Activity 

(pCi/L) 

Known 

Value[1] ± 

CSU[2] 

(pCi/L) 

Measured 

Mean ± 

SD[3] 

(pCi/L) 

Required 

Method 

Uncertainty[4] 

uMR (pCi/L) 

Required 

Relative 

Method 

Uncertainty 

φMR 

Measured 

Relative 

Standard 

Deviation 

(k=1) 

MDC 230Th 15 12.45±0.79 10.2 ±1.9 5 n/a 19 % 

MDC 226Ra 60 55.2±1.5 85±28 55 n/a 33 % 

MDC 228Ra 30 30.4±0.2 39±12 30 n/a 31 % 

1⁄2 × AAL 230Th 20 22.5 ± 1.2 14.9 ± 2.2 12 pCi/L n/a 15% 

1⁄2 × AAL 226Ra 90 75.0 ± 2.0 94 ± 32 54 pCi/L n/a 34% 

1⁄2 × AAL 228Ra 30 41.4 ± 0.65 43.2 ± 9.8 22 pCi/L n/a 23% 

AAL 230Th 40 37.5 ± 2.1 31.4 ± 4.2 12 pCi/L n/a 13% 

AAL 226Ra 180 164.9 ± 4.5 138 ± 18 54 pCi/L n/a 13% 

AAL 228Ra 60 62.47 ± 

0.99 74 ± 12 31 pCi/L n/a 16% 

3 × AAL 230Th 120 104.9 ± 6.3 73 ± 12 n/a 33% 16% 

3 × AAL 226Ra 540 449 ± 12 431 ± 52 n/a 33% 12% 

3 × AAL 228Ra 90 180.1 ± 2.8 199.3 ± 6.8 n/a 50% 3.4% 

[1] The known values were calculated by dilution of the tracers added to the surrogate matrix. 

[2] CSU – combined standard uncertainty (k=1). 

[3] SD – Standard deviation of the observed measurements 

[4] uMR = φMR × as-spiked concentration of the test sample at the AAL 

All of the measurement quality objectives in the method development plan were achieved. 

The details of the measurement synopses in Table 3 are found in Section 9. 
July - 2014 17 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

7.0 Method Development Plan 

The methods for gross alpha and gross beta activity were evaluated for four important 

performance characteristics for radioanalytical methods specified in Quality Assurance Project 

Plan Validation of Rapid Radiochemical Methods for Radionuclides Listed in EPA’s 

Standardized Analytical Methods (SAM) for Use During Homeland Security Events (EPA 2012). 

These include method uncertainty, detection capability, bias, and analyte activity range. A 

summary of the manner in which these performance characteristics were evaluated is presented 

below. Chemical yield of the method, an important characteristic for method ruggedness, is not 

specifically evaluated on an ongoing basis as this method is not radionuclide specific. Tracers 

were used in method development to assess recovery, however, to provide information on 

method ruggedness. See Attachment I for further discussion. 

Three counting methods were evaluated during the method development to determine 

the counting method to be used for method testing. Gas proportional counting was eliminated 

as a method of gross alpha or beta analysis because the high concentration of dissolved solids 

prevented the achievement of activity concentration detection limits that were reasonable due to 

self-attenuation and due to challenges encountered in preparing the test source. The final method 

utilizes liquid scintillation counting and high purity germanium gamma spectrometry. The 

proposed testing combinations are shown in Table 4. 

Table 4 – Proposed Sample Processing and Counting Combinations 

Method Processing Method Gamma 

Spectrometry 

Liquid Scintillation 

Counting 

Gas Proportional 

Counting [1] 

Gross Alpha Chemical Separation X X 

Gross Beta Non-destructive Count X 

[1] Eliminated from final testing. 

7.1 Method Uncertainty 

The method uncertainty for gross alpha and gross beta activity was initially estimated 

based on the gamma analysis of the untreated field sample and spiked demineralized water and 

surrogate MDRM sample spikes. Based on those trials, sample target concentrations were 

derived and finalized as noted in Table 5. 
July - 2014 18	 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 5 – Actual Sample Concentrations Used for MD Process 

Sample Type 

Minimum 

Number 

Analyzed 

Spike 

Concentration 

Gross Alpha 

by LSC (as 

fraction of 

the AAL) 

AAL = 37.5 

pCi/L 

226Ra by 

Gamma 

Spectrometry 

(as fraction of 

the AAL) 

AAL = 164.9 

pCi/L 

228Ra by 

Gamma 

Spectrometry 

(as fraction of 

the AAL) 

AAL = 62.47 

pCi/L 

Demineralized 

Water Blanks 7 Blank 0 0 0

Surrogate MDRM 

Blanks 7 Blank 0 0 0

Surrogate MDRM 

Spikes 10 MDC 0.33 0.33 0.49

Surrogate MDRM 

Spikes 

7 1⁄2 × AAL 0.60 0.45 0.65 

Surrogate MDRM 

Spikes 7 AAL 1.0 1.0 1.0

Surrogate MDRM 

Spikes 7 3 × AAL 2.8 2.7 2.9 

Internal MDRM proficiency test samples were prepared: 

•	 The performance of gross alpha as evaluated using two difference radioelements as

follows:

o	 Thorium, uranium, and polonium: the performance of the chemical separation / LSC

approach was evaluated based on recovery of 230Th added to the MDRMs since

characterization of the method in Phase 1 demonstrated that Th, U, and Po behave

similarly using this method.

o	 226Ra: The alpha activity as determined by gamma spectrometry was used to validate

the method based on recovery of 226Ra. This MDRM contained the alpha-emitting

radionuclide 226Ra.

•	 Gross beta as determined by gamma spectrometry reflects the activity of beta-emitting

decay progeny of 226Ra and 228Ra and the progeny of the 228Ra.

The respective concentrations for the test samples are noted in Table 5. The method 

was evaluated against the required method uncertainty values identified in Table 2. 
July - 2014 19	 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

7.2 Detection Capability 

The detection capability for gross alpha by LSC (Th/U/Po) was estimated at 10 pCi/L. 

For 226Ra by gamma spectrometry, it was estimated at 60 pCi/L, and for gross beta based on 

228Ra7

 for all significant beta emitters was estimated at 30 pCi/L. In accordance with the 

guidance provided in the MVG, the critical net concentration (CLNC) of the method was to be 

estimated based on the results of at least seven blank samples. Results from ten replicate samples 

having an “as tested” concentration at the required MDC being tested were compared to the 

critical net concentration to determine method detection capability. It should be noted that the 

verification of the required MDC for gross beta failed to meet criteria when tested at the 15 

pCi/L level. The test was repeated using test samples spiked at twice the initial activity indicating 

that the method is capable of meeting a required minimum detectable concentration value at the 

30 pCi/L level. 

7.3 Method Bias 

Two types of method bias were evaluated, absolute and relative. 

Absolute Bias 

Absolute bias was determined as a method performance parameter. The results from the 

seven blank samples for the required MDC evaluation were evaluated for absolute bias according 

to the protocol and equation presented in the Method Validation Guide for Qualifying Methods 

Used by Radiological Laboratories Participating in Incident Response Activities (EPA 2009). 

Absolute bias was to be determined as a method performance parameter; however, there was no 

acceptance limit for bias established for the method in this method development process. 

The following protocol was used to test the gross alpha water method for absolute bias: 

1. Calculate the mean ( X ) and estimated standard deviation (sX) for “N” (at least seven) blank

sample net results (in the case of gamma spectrometry measurements 13 were used as the

demineralized water blank and the blank surrogate were indistinguishable from each other)

2. Use the equation below to calculate the |T| value:

X 

T = (1) 

s X / N 

3. An absolute bias in the measurement process is indicated if:

 T > t 1− α / 2 (N − 1) (2) 

where: 

T represents the absolute value of the statistical t-value determined from analysis of the 

samples analyzed, and 

The analysis for 228Ra was performed using the gamma ray emissions of its first progeny, 228Ac, which emits a gamma ray at 911 keV. See 

discussion at the end of Section 6.1. 

7 
July - 2014 20	 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

t1−α/2 (N–1) represents the (1 – α/2)-quantile of the t-distribution with N–1 degrees of 

freedom. 

For seven blanks (or in the case of gamma spec 13 blanks), an absolute bias is identified 

at a significance level of 0.05, when |T| > t1−α / 2 . 

Relative Bias 

The results from the replicate samples for each of the three test levels and at the MDC 

level were evaluated for relative bias according to the protocol and equation presented in the 

Method Validation Guide for Qualifying Methods Used by Radioanalytical Laboratories 

Participating in Incident Response Activities (EPA 2009). No acceptable relative bias limit was 

specified for this MD process. 

The following protocol was used to test the gross alpha method for relative bias: 

1. Calculate the mean ( X ) and estimated standard deviation (sX) of the replicate results for

each method test level.

2. Use the equation below to calculate the |T| value:

X − K

T = (3) 

s 

2 

X / N + u

2

(K)

where: 

 |T| is the average measured value 

sx is the experimental standard deviation of the measured values 

N is the number of replicates 

K is the reference value 

u(K) is the standard uncertainty of the reference value 

A relative bias in the measurement process is indicated if: 

 

T > t	 

1−α / 2 (ν eff ) (3a)

The number of effective degrees of freedom for the t-statistic is calculated as follows: 

 

 u

2 (K)

2 

ν eff = (N − 1) 1+
   2  (4)

 sX / N 

Where νeff as calculated by the equation generally is not an integer so νeff should be 

truncated (rounded down) to an integer. Then, given the significance level, 0.05, the critical 

value for |T| is defined to be t1−α/2(νeff), the (1 – α/2)-quantile of the t-distribution with νeff degrees 

of freedom (see MARLAP Appendix G, Table G.2). 
July - 2014 21 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

7.4 Analyte Concentration Range 

The gross alpha method was evaluated for the required method uncertainty at three test 

level activities. The seven replicate PT samples from each test level concentration were 

analyzed. The three “targeted” and “known” test level activities are presented in Table 3. Note 

that the final test concentration values for the PT samples varied from the proposed test levels 

but that these values were within the sample preparation specifications provided to the 

laboratory. 

The gross beta method was evaluated for required method uncertainty using the gamma 

spectrometry software criterion of ≤ 50% and the combined standard uncertainty as calculated by 

the gamma spectrometry software. 

7.5 Method Specificity 

The purpose of this method is to perform a gross activity measurement. The specificity 

relates only to gross alpha or gross beta analysis. The separation steps employed were intended 

to isolate groups of radionuclides that were either alpha or beta emitters. In the development of 

the final method, certain tracers were used to follow the separation of the surrogate radionuclides 

used for the analysis. 

7.6 Method Ruggedness 

Method ruggedness was evaluated primarily in Phase 1 of the MD process for the effects that the 

extreme combination of chemical compounds and high dissolved solids content would have on 

the method. In this phase, the method was modified to use a general chemical separation process 

for isotopes of uranium, thorium and polonium, and gamma spectrometry was selected for 

analysis of beta emitting radionuclides and 226Ra. The ruggedness of the method was testing 

during Phase 1 using the EPA provided sample and with different radionuclides spiked into the 

surrogate matrix. See Attachment 1 for details on this testing. 
July - 2014 22 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

8.0 Techniques Used to Evaluate the Measurement Quality 

Objectives for Methods Development Project 

A general description of the specifications and techniques used to evaluate the required 

method uncertainty, required MDC and bias was presented in Section 6. The detailed method 

evaluation process for each MQO and bias is presented in this section. 

8.1 Required Method Uncertainty 

The gross alpha and gross beta activity method was evaluated following the guidance 

presented for “Level E Method Validation: Adapted, Newly Developed Methods, Including 

Rapid Methods” in Method Validation Guide for Qualifying Methods Used by Radiological 

Laboratories Participating in Incident Response Activities (EPA 2009) and Chapter 6 of MultiAgency Radiological Laboratory Analytical Protocols Manual (MARLAP 2004). 

MARLAP “Level E” method validation requires the laboratory to conduct a method

development study wherein seven (or more) replicate samples from each of the three concentration 

levels are analyzed according to the method. The concentration test levels analyzed are listed in 

Table 3. For validation “Level E,” internally prepared PT samples consisting of NIST-traceable 

230Th, 228Ra and 226Ra spiked into the surrogate matrix to create a method development reference 

material (MDRM). In order to determine if the proposed method met the project MQO 

requirements for the required method uncertainty, each PT sample result was compared with the 

method uncertainty acceptance criteria listed in Tables 6A, 6B, and 6C. “Level E” validation 

stipulates that for each test sample analyzed, the measured value must be within ±3.0 uMR 

8

 for 

test level activities at or less than the AAL, or ±3.0 φMR 

9

 for test level activities above the AAL. 

8.2 Required Minimum Detectable Concentration 

The analytical results reported for the PT samples having a gross alpha and gross beta 

activity at the tested MDCs (Th/U/Po by LSC alpha at 12 pCi/L; 226Ra alpha by gamma 

spectrometry at 55 pCi/L; 228Ra beta at 30 pCi/L) were evaluated according to Sections 5.5.1 and 

5.5.2 of Testing for the Required MDC in Method Validation Guide for Qualifying Methods 

Used by Radiological Laboratories Participating in Incident Response Activities (EPA 2009). 

For this method development process, the terms “MDC” and “Critical Net Concentration” are used. 

The State Hygienic Laboratory at the University of Iowa analyzed the prepared PT samples in 

accordance with the final proposed method. 

Critical Net Concentration 

In order to evaluate whether the combined method can meet the required MDC 

(Th/U/Po by LSC alpha at 12 pCi/L; 226Ra alpha by gamma spectrometry at 55 pCi/L; 228Ra beta 

at 30 pCi/L), the critical net concentration, as determined from the results of analytical blanks, 

must be calculated. The critical net concentration (CLNC) with a Type I error probability of α = 

8

 uMR is the required method uncertainty 

9 φMR is the required relative method uncertainty 

July - 2014 23
July - 2014 24 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

0.05, was calculated using the following equation (consistent with MARLAP, Chapter 20, 

Equation 20.35): 

CL ( pCi) = t (n −1) × S	 (7) NC 1−α Blanks 

Where: 

SBlanks is the standard deviation of the n blank-sample net results (corrected for 

instrument background) in radionuclide concentration units of pCi/L, and 

t1−α(n-1) is the (1 – α)-quantile of the t-distribution with n–1 degrees of freedom (see 

MARLAP Table G.2 in Appendix G). For this method development study, a Type I error 

rate of 0.05 was chosen. 

For example, for seven (minimum) blank results (six degrees of freedom) and a Type I error 

probability of 0.05, the previous equation reduces to: 

CL NC ( pCi ) = 1.94 × S	 (8) 	 Blanks

The use of the above equations assumes that the method being evaluated has no bias. 

Required MDC 

Each of the analytical results reported for the PT samples having concentration at the 

required MDC (Th/U/Po by LSC alpha at 12 pCi/L; 226Ra alpha by gamma spectrometry at 55 

pCi/L; 228Ra beta at 30 pCi/L) were compared to the estimated critical net concentration for the 

method. The following protocol was used to verify a method’s capability to meet the required 

method MDC for a radionuclide-matrix combination: 

I. Analyze a minimum of seven matrix blank samples for the radionuclide. 

II. From the blank sample net results, calculate the estimated Critical Net Concentration,

CLNC.

III.	 Analyze ten replicate samples spiked at the required MDC.

 

IV. From the results of the ten replicate samples spiked at the required MDC, determine the

number (Y) of sample results at or below the estimated CLNC.

 

V. If Y ≤ 2, the method evaluated at the required MDC passes the test for the required MDC

specification.

 

VI. If Y > 2, the method evaluated at the required MDC fails the test for the required MDC

specification. 
 

July - 2014 25 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

9.0 Evaluation of Experimental Results 

Only the experimental results for Phases 2 and 3 of the MD process are reported and 

evaluated in this study. Information presented in this section will include results for Sections 6 

and 7. The gross alpha and gross beta activity concentration results were evaluated for the 

required method uncertainty, required MDC, and bias. 

9.1 Summary of the Method 

The full method for the analysis is located in Attachment III. A brief description of 

each part of the method is described here. 

Th, U, Po Gross Alpha by LSC 

A 300 mL sample is treated with permanganate in ammonaical solution to coprecipitate 

all radionuclides in the naturally occurring series. The mixture is settled and the supernatant 

solution discarded. The residue is dissolved in hydrochloric acid and passed through a TRU 

ResinTM column. 10 Thorium, uranium and polonium are eluted from the resins using ammonium 

oxalate. The eluent is transferred to a liquid scintillation vial as the final sample test source and 

counted in the alpha emission region of the liquid scintillation spectrum. The final sample test 

source is counted for 30 minutes. 

226Ra Alpha by Gamma Spectrometry 

A sample test source of 3 L is counted directly by gamma ray spectrometry. The 

activity concentration of 226Ra is determined by gamma ray analysis using the 186 keV gamma 

ray region (assumes no significant amount of 235U compared to the amount of 226Ra in the 

sample). The sample is counted for 12 hours or long enough to achieve the required method 

uncertainty. 

228Ra Beta by Gamma Spectrometry 

The sample test source of 3 L is counted directly by gamma ray spectrometry. In 

addition to 228Ra being determined indirectly by analysis of its first progeny 228Ac (911 or 338 

keV) several other radionuclides are determined directly by their gamma ray emission and others 

may be determined indirectly through analysis of a parent or progeny radionuclide that is a 

gamma ray emitter. The sample is counted for 12 hours or long enough to achieve the required 

method uncertainty. 

9.2 Required Method Uncertainty 

Tables 6A through 6C show the measured results for each of the samples analyzed and 

the testing requirements for each level. The “known” values and combined standard 

uncertainty of the known values (“CSU known”) are based on the amount of NIST-traceable 

standards added to the samples. The allowable range of results is calculated by taking the known 

10 Eichrom Technologies, LLC, Lisle, IL. 
July - 2014 26 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

value and adding (to get the upper value of the range) and subtracting (to get the lower value of 

the range) 

three times the required method uncertainty (3.0 × uMR). For example, in Table 6A, the 

allowable range for gross alpha for Test Level 2 is 37.5 ± (3.0 × 12) pCi/L or 1.5 to 74 pCi/L 

(rounded to two significant figures). 
July - 2014 27 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 6A – Th, U. Po Gross Alpha by LSC—Analytical Results for Required Method Uncertainty Evaluation 

Nuclide: Gross Alpha (Th-230) Matrix: FWHFPO AAL Tested: 37.5 pCi/L 

Proposed Method: U, Th, Po Gross Alpha by LSC 

Required Method Validation Level: MARLAP “E” 

Required Method Uncertainty, uMR: 12 pCi/L at and below AAL; 33% above AAL 

Acceptance Criteria: 

Test Levels 1 and 2: 3.0 × uMR = known value of sample in test level ± 36 pCi/L 

Test Level 3: 3.0 × φMR = quoted known value of sample ± 99% of known value of sample (pCi/L) 

Test Level 1 

Test Value = 22.5 ± 1.2 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

22.5 1.2 

13.68 0.96

-14 to 59 

Y 

2 18.1 1.1 Y

3 14.93 0.99 Y

4 11.74 0.92 Y

5 15.7 1.0 Y

6 13.45 0.96 Y

7 16.9 1.0 Y

Test Level 2 

Test Value = 37.5 ± 2.1 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

37.5 2.1 

31.0 1.3

1.5 to 74 

Y 

2 38.8 1.5 Y

3 32.8 1.3 Y

4 32.0 1.3 Y

5 24.8 1.2 Y

6 33.0 1.4 Y

7 27.2 1.2 Y

8 31.5 1.3 Y

Test Level 3 

Test Value = 104.9 ± 6.3 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

104.9 6.3

72.6 2.0

1.0 to 210 

Y 

2 60.7 1.8 Y

3 67.5 1.9 Y

4 60.2 1.8 Y

5 76.5 2.1 Y

6 86.5 2.2 Y

7 89.3 2.3 Y

* Quoted uncertainty (one sigma) 

** Combined standard uncertainty, k = 1 
 

 

July - 2014 28 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 6B – 226Ra Alpha by Gamma Spectrometry - Analytical Results for Required Method Uncertainty Evaluation 

Nuclide: Gross Alpha (226Ra) Matrix: FWHFPO AAL Tested: 164.9 pCi/L 

Proposed Method: 226Ra Alpha by Gamma Spectrometry 

Required Method Validation Level: MARLAP “E” 

Required Method Uncertainty, uMR: 54 pCi/L at and below AAL; 33% above AAL 

Acceptance Criteria: 

Test Levels 1 and 2: 3.0 × uMR = known value of sample in test level ± 162 (pCi/L) 

Test Level 3: 3.0 × φMR = quoted known value of sample ± 99% of known value (pCi/L) 

Test Level 1 

Test Value = 75.0 ± 2.0 pCi /L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

75.0 2.0

58.55 18.1

-87 to 240 

Y 

2 93.7 41.8 Y 

3 107.3 36.45 Y 

4 101 41.8 Y 

5 153 42.8 Y 

6 62.5 19.5 Y 

7 84.1 33.2 Y 

Test Level 2 

Test Value = 164.9 ± 4.5 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

164.9 4.5

125.8 22

2.9 to 330 

Y 

2 140 21.6 Y

3 144 22.2 Y

4 110 22.6 Y

5 167 43.6 Y

6 131 22.9 Y

7 150 22.7 Y

8 125.8 22 Y

Test Level 2 

Test Value = 37.5 ± 2.1 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

37.5 2.1 

31.0 1.3

1.5 to 74 

Y 

2 38.8 1.5 Y

3 32.8 1.3 Y

4 32.0 1.3 Y

5 24.8 1.2 Y

6 33.0 1.4 Y

7 27.2 1.2 Y

8 364 32.2 Y

* Quoted uncertainty (one sigma) 

** Combined standard uncertainty, k=1. 
July - 2014 29 

 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 6C – 228Ra Beta by Gamma Spectrometry—Analytical Results for Required Method Uncertainty Evaluation 

Nuclide: Gross Beta (228Ra) Matrix: FWHFPO AAL Tested: 62.47 pCi/L 

Proposed Method: 228Ra Beta by Gamma Spectrometry 

Required Method Validation Level: MARLAP “E” 

Required Method Uncertainty, uMR: 31 pCi/L at and below AAL; 50% above AAL 

Acceptance Criteria: 

Test Levels 1 and 2: 3.0 × uMR = known value of sample in test level ± 93 pCi/L 

Test Level 3: 3.0 × φMR = quoted known value of sample ± 150% of known value (pCi/L) 

Test Level 1 

Test Value = 41.4 ± 0.65 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

pCi/L 

Acceptable 

Y/N 

1 

41.40 0.65

44.9 6.03

-52 to 130 

Y 

2 50.2 7.13 Y

3 54 6.46 Y

4 39.2 4.61 Y

5 52.2 5.08 Y

6 30.6 5.07 Y

7 31.1 5.5 Y

Test Level 2 

Test Value = 62.47± 0.99 pCi/L 

Sample # pCi/L 

Known CSU* pCi/L 

Measured CSU** Allowable Range pCi/L 

Acceptable 

Y/N 

1 

62.47 0.99

77.2 6.67

-31 to 160 

Y 

2 80.2 8.44 Y

3 53.2 6.13 Y

4 82.4 10.5 Y

5 85.3 10.5 Y

6 62.3 6.52 Y

7 76.7 9.17 Y

8 77.2 6.67 Y

Test Level 2 

Test Value = 37.5 ± 2.1 pCi/L 

Sample # pCi/L 

Known 

CSU* 

Known 

pCi/L 

Measured 

CSU** 

Measured 

Allowable Range 

(pCi/L) 

Acceptable 

Y/N 

1 

37.5 2.1

31.0 1.3

1.5 to 74 

Y 

2 38.8 1.5 Y

3 32.8 1.3 Y

4 32.0 1.3 Y

5 24.8 1.2 Y

6 33.0 1.4 Y

7 27.2 1.2 Y

* Quoted uncertainty (one sigma) 

** Combined standard uncertainty, k=1. 
July - 2014 30 

Based on the results in Tables 6A to 6C it may be concluded that: 

•	 A required method uncertainty of 12 pCi/L can be achieved at an action level of 38 pCi/L

for gross alpha analysis using LSC

•	 A required method uncertainty of 54 pCi/L can be achieved at an action level of 165

pCi/L for 226Ra analysis using gamma spectrometry

•	 A required method uncertainty of 31 pCi/L can be achieved at an action level of 62 pCi/L

for 228Ra analysis using gamma spectrometry.

 

 

 

 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

These results meet the measurement quality objectives from the method development plan. 

Tables 7A to 7C provide summary information regarding the expected variability of the 

results for an individual analysis and test level. In each case, the experimental standard deviation 

was considerably less than the required method uncertainty indicated that the method is capable 

of meeting the method uncertainty MQO. 

Table 7A – Th, U, Po Gross Alpha by LSC—Experimental Standard Deviation of the Seven PT Samples by Test Level (230Th) 

Test Level 

Mean 

Concentration Measured 

(pCi/L) 

Experimental Standard 

Deviation[1] 

(pCi/L) 

Required Method 

Uncertainty 

(pCi/L) 

1 14.9 2.2 12

2 (AAL) 31.4 4.2 12 

3 73 12 35[2] 

[1]	 Standard deviation of the seven measurements. 

[2]	 Calculated by multiplying the known value of Test Level 3 by the required relative method uncertainty. 

Table 7B – 226Ra Alpha by Gamma Spectrometry—Experimental Standard Deviation of the Seven PT Samples by Test Level 

Test Level 

Mean 

Concentration Measured 

(pCi/L) 

Experimental Standard 

Deviation[1] 

(pCi/L) 

Required Method 

Uncertainty 

(pCi/L) 

1 94 32 54

2 (AAL) 138 18 54 

3 431 52 150[2] 

[1]	 Standard deviation of the seven measurements. 

[2]	 Calculated by multiplying the known value of Test Level 3 by the required relative method uncertainty. 
July - 2014 31 

 

 

 

 

 

 

 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 7C – 228Ra Beta by Gamma Spectrometry—Experimental Standard Deviation of the Seven PT Samples by Test Level 

Test Level 

Mean 

Concentration Measured 

(pCi/L) 

Experimental Standard 

Deviation[1] 

(pCi/L) 

Required Method 

Uncertainty 

(pCi/L) 

1 43.2 9.8 31

2 (AAL) 74 12 31 

3 199.3 6.8 90[2] 

[1] Standard deviation of the seven measurements. 

[2] Calculated by multiplying the known value of Test Level 3 by the required relative method uncertainty. 

9.3 Required Minimum Detectable Concentration 

Critical Net Concentration 

The method for Th, U, Po gross alpha by LSC in an FWHFO matrix was evaluated for 

a required MDC using surrogate water blanks that were taken through the analytical processes of 

gross alpha chemical separation and LSC. Ra-226 and Ra-228 were evaluated for the MDC by 

direct analysis of the MDC verification samples by gamma counting. 

Demineralized water blanks for the gross alpha determination by LSC yielded an 

expected blank value of zero since the average of these blanks was used to determine the 

background subtraction value, while surrogate samples yielded values greater than zero. The 

elevated result for surrogates is likely due to the contribution of low levels of naturally occurring 

radionuclides in the reagents used to make the surrogate. Thus, the surrogate water blanks were 

used to determine a matrix appropriate critical net concentration for the verification of the MDC. 

The results of the demineralized water and surrogate blanks for gross alpha are shown in Tables 

8A and 8B. 

Table 8A – Th, U, Po Gross Alpha by LSC—Blank Water Samples 

Sample ID Concentration (pCi/L) CSU* (pCi/L) 

DI Water Blank 1 0.07 0.69 

DI Water Blank 2 -0.12 0.68 

DI Water Blank 3 0.54 0.71 

DI Water Blank 4 -0.12 0.68 

DI Water Blank 5 -0.59 0.66 

DI Water Blank 6 0.07 0.69 

DI Water Blank 7 0.15 0.69 

Mean** (pCi/Liter) 0.00 

Standard Deviation ** (pCi/Liter) 0.34 

Critical Net Concentration (pCi/Liter) 0.66 

* Combined standard uncertainty, k=1 or coverage factor of 1. 

** Mean and standard deviation were calculated before rounding. 
July - 2014 32 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 8B – Th, U, Po Gross Alpha by LSC—Surrogate Water Samples 

Sample ID Concentration (pCi/L) CSU* (pCi/L) 

Surrogate Blank 1 8.86 0.85 

Surrogate Blank 2 6.95 0.85 

Surrogate Blank 3 7.92 0.83 

Surrogate Blank 4 6.53 0.79 

Surrogate Blank 5 7.81 0.82 

Surrogate Blank 6 7.03 0.80 

Surrogate Blank 7 7.03 0.80 

Mean** (pCi/Liter) 7.45 

Standard Deviation ** (pCi/Liter) 0.79 

Critical Net Concentration (pCi/Liter) 1.5 

* Combined standard uncertainty, k=1 or coverage factor of 1. 

** Mean and standard deviation were calculated before rounding. 

The results for the demineralized water blanks and surrogate blanks measured by 

gamma ray spectrometry were indistinguishable from each other (i.e., statistically the same). 

Therefore these data were pooled and used to calculate the critical level net concentration for the 

226Ra and 228Ra measurements. The pooled results are shown in tables 8C and 8D. 

Table 8C – 226Ra Alpha by Gamma Spectrometry in Demineralized and Surrogate Water Samples 

Sample ID Concentration (pCi/L) CSU* (pCi/L) 

Surrogate 1 -12.6 17.3 

Surrogate 2 -17.9 18.3 

Surrogate 4 -15.78 34 

Surrogate 5 -8.99 19.5 

Surrogate 6 14.3 24.5 

Surrogate 7 -12.1 17.4 

Surrogate 8 -6.73 22.9 

DM Water Blank 1 53.5 26 

DM Water Blank 2 -6.4 17.8 

DM Water Blank 3 -1.94 28.6 

DM Water Blank 5 -45 30.7 

DM Water Blank 6 -18.3 24.8 

DM Water Blank 7 -9.94 21.3 

Mean** (pCi/Liter) -7 — 

Standard Deviation ** (pCi/Liter) 22 — 

Critical Net Concentration (pCi/Liter) 40 — 

* Combined standard uncertainty, k=1 or coverage factor of 1. 

** Mean and standard deviation were calculated before rounding. 
July - 2014 33 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 8D – 228Ra Gross Beta by Gamma Spectrometry in Demineralized and Surrogate Water Samples 

Sample ID Concentration (pCi/L) CSU* (pCi/L) 

Surrogate 1 11.8 5.24 

Surrogate 2 13.3 6.62 

Surrogate 4 14.9 5.7 

Surrogate 5 -9.54 11.1 

Surrogate 6 -16.2 23.8 

Surrogate 7 5.65 4.24 

Surrogate 8 -11.8 8.19 

DM Water Blank 1 -10.7 13.4 

DM Water Blank 2 -1.87 1.2 

DM Water Blank 3 -17.1 34.1 

DM Water Blank 5 -9.42 10.1 

DM Water Blank 6 -3.08 4.34 

DM Water Blank 7 -11.7 13.2 

Mean** (pCi/Liter) -4 

Standard Deviation ** (pCi/Liter) 11 

Critical Net Concentration (pCi/Liter) 20 

* Combined standard uncertainty, k=1 or coverage factor of 1. 

** Mean and standard deviation were calculated before rounding. 

Required MDC 

The method development plan based the estimated MDC values for gross alpha and gross 

beta on demineralized water blanks. The initial estimates of the MDCs targeted for 226Ra and 

228Ra proved to be too low and were adjusted to a higher concentration during the method development

 process. The most likely reason for this was increased background counts from low 

activity concentration of natural radioactivity in the surrogate matrix. 

The MDC data for each of the three evaluations are shown in Tables 9A through 9C. 

The determination of gross alpha using 226Ra as the radionuclide and gamma spectrometry as the 

measurement technique is not as sensitive as using liquid scintillation as the measurement 

technique.11 For this reason, the two different techniques for the gross alpha measurement have 

different MDC values. This is highlighted in the MDC results shown in Tables 9A and 9B. 

11 The abundance of the 186 keV gamma ray for 226Ra is only 3.3 % while the abundance of the alpha particle emission is 100 %. 
July - 2014 34 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 9A – Reported Results for Samples Containing Th, U, Po Gross Alpha by LSC[1] at the As-Tested MDC 

Value (12.45 pCi/L) 

Sample ID Concentration (pCi/L) CSU[2]

 (pCi/L) Test Result 

≤ CLNC (Y/N) 

MDC 1 12.08 0.93 N 

MDC 2 7.73 0.82 N 

MDC 3 13.72 0.96 N 

MDC 4 9.05 0.85 N 

MDC 5 11.89 0.92 N 

MDC 6 8.97 0.85 N 

MDC 7 8.62 0.84 N 

MDC 8 10.10 0.88 N 

MDC 9 10.57 0.89 N 

MDC 10 9.21 0.86 N 

Mean [3] (pCi/L) 10.2 

Standard Deviation of Results [3] (pCi/L) 1.9 

CLNC [4] (pCi/L) 1.5 

Acceptable maximum values ≤ CLNC 2

Number of results > CLNC 10

Number of results ≤ CLNC 0

Evaluation PASS 

[1] Samples spiked with 230Th. 

[2] Combined standard uncertainty, coverage factor k=1. 

[3] Mean and standard deviation were calculated before rounding. 

[4] Critical net concentration. CLNC based on the water blanks taken through the entire method. 

 
July - 2014 35 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 9B – Reported Results for 226Ra Alpha[1] by Gamma Spectrometry at the As-Tested MDC Value (55.2 pCi/L) 

Sample ID Concentration (pCi/L) CSU[2] (pCi/L) Test Result 

≤ CLNC (Y/N) 

MDC 1 148 42.1 N 

MDC 2 99.6 42.4 N 

MDC 3 79.2 34.13 N 

MDC 4 51.7 17 N 

MDC 5 102 44.9 N 

MDC 6 74.7 31.8 N 

MDC 7 72.8 36.6 N 

MDC 8 68 33.2 N 

MDC 9 58.9 25.4 N 

MDC 10 98.1 34 N 

Mean [3] (pCi/L) 85 

Standard Deviation of Results [3] (pCi/L) 28 

CLNC [4] (pCi/L) 40 

Acceptable maximum values ≤ CLNC 2

Number of results > CLNC 10

Number of results ≤ CLNC 0 

Evaluation PASS 

[1] Samples spiked with 226Ra. 

[2] Combined standard uncertainty, coverage factor k=1. 

[3] Mean and standard deviation were calculated before rounding. 

[4] Critical net concentration. CLNC based on the water blanks taken through the entire method. 

The initial MDC verification PTs for gross beta using gamma spectrometry turned out 

to be below the detection capability of the method as was demonstrated when an initial run failed 

to meet the acceptance criteria. It was determined that the samples initially counted for the 1⁄2 

AAL uncertainty determination (30.4 pCi/L) provided a more representative estimate of the MDC. 

Additional MDC test samples were prepared and counted and the results are reported in Table 

9C. A new set of samples was also prepared for testing of uncertainty at the “1⁄2 AAL” 

(approximately 65% of the AAL) and counted with results reported in Table 6C (41.4 pCi/L). 

The results for 228Ra (228Ac) as a measure of the gross beta activity were very reproducible. 

However, further work on other gamma ray emitters in the natural decay series needs to be 

performed to provide better estimation for the detection limits using this method. 
July - 2014 36 

 

 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 9C – Reported Results for 228Ra Beta[1] by Gamma Spectrometry at the As-Tested MDC Value (30.4 pCi/L) 

Sample ID Concentration (pCi/L) CSU [2] (pCi/L) Test Result 

≤ CLNC (Y/N) 

MDC 1 35.8 6.03 N 

MDC 2 44.2 5.45 N 

MDC 3 57.9 5.55 N 

MDC 4 35.5 5.59 N 

MDC 5 58.3 6.6 N 

MDC 6 40.5 4.53 N 

MDC 7 26.2 5.06 N 

MDC 8 34 3.52 N 

MDC 9 30.8 4.02 N 

MDC 10 26.2 5.31 N 

Mean [3] (pCi/L) 39

Standard Deviation of Results [3] (pCi/L) 12

CLNC [4] (pCi/L) 20

Acceptable maximum values ≤ CLNC 2 

Number of results > CLNC 10 

Number of results ≤ CLNC 0 

Evaluation PASS 

[1] Samples spiked with 228Ra. 

[2] Coverage factor k=1. 

[3] Mean and standard deviation were calculated before rounding. 

[4] Critical net concentration. CLNC based on the water blanks taken through the entire method. 

9.4 Evaluation of the Absolute and Relative Bias 

Test results for verification of the MDC and test levels 1–3 were evaluated for absolute 

and relative bias using the test process described in Section 7.3 above.12 The bias test results are 

summarized in Table 10. It should be noted that the presence of detectable levels of bias is not a 

criterion for the method development until the magnitude of the bias is significant enough to cause

results to fall outside the acceptance criteria of the required method uncertainty. In most 

cases bias was detected across the range of concentrations tested with highest levels of relative 

bias generally being associated with the lowest activity concentration samples. For example, the 

largest relative bias (percent) was observed for MDC samples for gross beta using 228Ra as a 

tracer. Please see further discussion of the bias in Section 9.5. 

12 For more complete treatments of the statistical detection and evaluation for absolute and relative bias see Method Validation 

Guide for Qualifying Methods Used by Radiological Laboratories Participating in Incident Response Activities (EPA 2009) 

and Quality Assurance of Chemical Measurements (Taylor 1987). 
July - 2014 37 

 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Table 10 – Absolute and Relative Bias for Gross Alpha and Gross Beta by the Three Measurements 

Type of 

Bias 

Gross 

Measurement 

(Radionuclide 

Measured) 

Known 

Value ± 

CSU (k=1), 

pCi/L 

Mean of 

Measurement 

± SD (k=1), 

pCi/L 

Difference 

from 

Known, 

pCi/L (%) 

Number of 

Measurements/ 

(Effective) 

Degrees of 

Freedom[1] 

│T│[1] tdf

[1] Bias[2] 

(Y/N)? 

Absolute Gross Alpha 

(

230Th, LSC) – 7.45 ± 0.79 7.45 7/6 2.447 24.8 Y 

Gross Alpha 

(

226Ra, GS) – -7 ± 22 7 13/12 2.179 1.09 N

Gross Beta 

(

228Ra/228Ac, GS) – -4 ± 11 4 13/12 1.12 2.17 

9 N 

MDC Gross Alpha 

(

230Th, LSC) 12.45±0.79 10.2 ±1.9 2.25 (-18) 10/70 2.28 1.99 Y 

Gross Alpha 

(

226Ra, GS) 55.2±1.5 85±28 27.2 (54) 10/9 3.36 2.26 Y 

Gross Beta 

(

228Ra/228Ac, GS) 30.4±0.2 39±12 8.6 (28) 10/9 2.32 2.26 Y 

Level 1 Gross Alpha 

(

230Th, LSC) 22.5±1.2 14.9±2.2 7.6 (-34) 7/64 5.05 2.00 Y 

Gross Alpha 

(

226Ra, GS) 75.0±2.0 94±32 19 (25) 7/6 1.59 2.45 N 

Gross Beta 

(

228Ra/228Ac, GS) 41.40±0.65 43.2±9.8 1.8 (4.3) 7/6 0.47 2.45 N 

Level 2 Gross Alpha 

(

230Th, LSC) 37.5±2.1 31.4±4.2 6.1 (-16) 8/61 2.39 2.00 Y 

Gross Alpha 

(

226Ra, GS) 164.9±4.5 138±18 26.9 (-16) 8/12 3.23 2.18 Y 

Gross Beta 

(

228Ra/228Ac, GS) 62.47±0.99 74±12 11.5 (18) 8/6 2.52 2.45 Y 

Level 3 Gross Alpha 

(

230Th, LSC) 104.9±6.3 73±12 31.9 (-30) 7/55 4.14 2.00 Y 

Gross Alpha 

(

226Ra, GS) 449±12 431±52 18 (-4.0) 8/11 0.76 2.20 N 

Gross Beta 

(

228Ra/228Ac, GS) 180.1±2.8 199.3±6.8 19.2 (11) 8/28 5.06 2.05 Y 

[1] Assessment of relative bias was performed at MDC and Levels 1, 2, and 3. 

[2]	 │T│ is the absolute value of the t-statistic, and tdf is the effective degrees of freedom of the t-statistic. They are defined in Section 7.3 and 

represent the statistical factors for the actual measurement data and for data from a normal distribution. 
 

July - 2014 38 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

9.5 Method Ruggedness 

Ruggedness represents the ability of a method to be unaffected by changes in the 

components of the sample or the measurement system. The matrix selected for this project was 

based on that of a single sample of FPWHFO and will not necessarily represent method 

performance in samples of significantly different composition such as FPWHFO collected at 

different times in the life of a well or from different wells or regions. Nonetheless, this matrix is 

considered to be a particularly challenging one due to its extremely high dissolved solids content 

and its complexity (very elevated levels of divalent cations). This affected the bias and 

detectability of each of the three measurements associated with the method. 

Based on testing performed at the end of the method development process, gross alpha 

activity determined by liquid scintillation counting of the separated U, Th, and Po fraction of the 

sample was measured with recoveries ranging from 84–96 % of the expected value (see Section 

11 and Attachment II, “Flow Chart for the Alpha Beta Methods Attempted “ and Figure 6). The 

low bias was confirmed during formal development testing with an average gross alpha recovery for 

the 14 test measurements at test levels 2 and 3 of 77±11% (k=1) of the known value and 

results ranging from 57–104 %.13 Although these results easily meet testing acceptance 

criteria, the systematic low bias and the observation that quantitative (or near-quantitative) 

recovery of 230Th is not achieved raises concerns about the ruggedness of the chemical separation 

method. Final method testing was performed using 230Th, which had the lowest recovery of the 

three radioelements evaluated in final preliminary tests, but not uranium or polonium. Since 

uranium and polonium were not quantitatively recovered in preliminary testing, it is reasonable 

to expect similar low bias for these elements with real test samples. 

Gamma spectrometry, by its nature as a non-destructive method, is more rugged than 

methods that rely on chemical separations since there can be no losses prior to the analytical 

measurement and variability of the matrix will have less potential to impact analytical results. 

The average recovery calculated from values presented in Table 6B for the 14 test-level-2 and 3 

analytical measurements of 226Ra was 90±13% (k=1) with individual values ranging from 67– 

108%. The average recovery calculated from values presented in Table 6C for the 14 analytical

measurements of 228Ra spikes at test levels 2 and 3 was 114±14% (k=1) with individual values 

ranging from 85–137%. While it likely would be possible to improve the process used for the 

gamma spectrometry measurement, better control of the sample (i.e., no introduction of added 

variability from chemical separations) makes gamma spectrometry a very rugged technique. 

Thus, there is little concern that measured values will adequately reflect the performance of the 

gamma spectrometry technique on real-world samples. 

13 Note that the level of uncertainty for samples for the verification of the MDC and test level 1 due to the low concentrations in these samples. 
July - 2014 39 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

10.0 Timeline to Complete a Batch of Samples 

It is important for the laboratory to know how long an analysis will take so that they 

can provide timely results back to their clients. Historically a batch of gross alpha and gross beta 

analyses will take on the order of 3–4 days (based on the SDWA methods). There are two 

separate timelines for the analysis based on the two different analytical methods that are used for 

measuring the gross alpha and gross beta activity concentrations. Gross Th, U, and Po using 

gross alpha analysis by LSC, from sample preparation to final results reporting, can take place in 

3 hours for a single sample, or approximately one day for a batch of 20 samples (assuming a 

single LSC is available). The gamma spectrometry count for 228Ra beta and 226Ra alpha can 

require about 12 hours for a single sample and can process about 2 samples per day per 

spectrometer. Assuming a single gamma ray spectrometer is available, a batch of 20 samples 

would require 10 days for analysis. Laboratories will need to judge their processing times for a 

batch of samples based on the number of instruments they have available. 

See Attachment II for a breakdown of the times for the individual steps shown in the 

flowchart in Section 17.4. 
July - 2014 40 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 41 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

11.0 Reported Modifications During Development and 

Recommendations for Future Work 

The development of a straight-forward, inexpensive, single measurement method for 

gross alpha and gross beta screening of FPWHFO samples was hampered by the complexity of 

the matrix itself. Significant preliminary effort was spent in Phase 1 modifying the approach 

initially conceived to accommodate a FPWHFO matrix which turned out to be particularly 

challenging. The development process will be briefly summarized here to provide perspective. 

Attachment I is a more complete presentation of various trials and modification that had to be 

made during the Phase 1 method development process that preceded the final method development

process. 

Several classic water methods for gross activity testing were explored in hopes that a 

simple non-destructive analysis (i.e., an analysis without chemical separation) could be 

performed. Unfortunately solids content in the gram per liter range is 200–1000 times above the 

range that Method 900.0 evaporation or direct counting by liquid scintillation (e.g., ASTM 

D7282) can accommodate. Digestion and fusion techniques were considered but in view of the 

high non-volatile solids content of the sample matrix, would not have made the matrix more 

amenable to processing. All attempts to use these classic approaches failed to yield acceptable 

results. 

A variety of classic chemical separation techniques were explored for chemically 

isolating radium, thorium, uranium, or polonium. Among the approaches explored were barium 

sulfate precipitation techniques (e.g., EPA Method 900.1 or 903.0, SM 7110C), barium chromate 

precipitations (e.g., EPA Method 905.0) and solid phase extraction with chelating agents, such as 

EmporeTM Radium RadDisks. Again, the gram per liter levels of barium, strontium, and calcium 

interfered with every attempt to chemically isolate radium (also a divalent cation) together with 

thorium, uranium, and polonium. 

A radon deemanation method (Rad7TM electronic radon detector) proved to be 

reasonably successful but this approach had to be abandoned due to concerns about foaming of 

the sample and extended turn-around times as long as 7–21 days (required for ingrowth of 

222Rn). Other radon emanation techniques, such as mineral oil extraction of radon with liquid 

scintillation counting or radon deemanation similar to the classic approach used in EPA Method 

903.1 could be considered as possible avenues for future exploration for more sensitive 

radionuclide-specific determinations of 226Ra. 

One of the methods used to initially characterize the sample, gamma spectrometry, 

proved to be one of the most viable, attractive, and rugged alternatives for the analysis of 

FPWHFO. The primary advantage of gamma spectrometry is its ability for simultaneous 

measurement of all gamma emitters present in the sample together with its nominal insensitivity 

to solids in the sample. In contrast to alpha and beta emissions, where sample solids above 100– 

200 mg interfere with measurements, the highly penetrating nature of gamma rays allows 

measurement of solid samples in the 3–5 kg range without chemical separations. The response of 

gamma spectrometers is also limited relative to that of liquid scintillation counters. Gamma 
Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

detection efficiencies are generally less than 10% of the efficiency for either alpha or beta 

emissions by liquid scintillation. Similarly, the gamma emission rate associated with natural 

chain alpha and beta emitters (3% to 45%) is low relative to the corresponding alpha and beta 

particle emission rates (nearly 100%). By increasing the size of the aliquant and the count time, 

however, it is possible to compensate, as least in part, for low response in the gamma detector. 

As a result, detection capabilities may be obtained for gamma spectrometry that are generally 

within a factor of 10–50 of those possible by direct measurement of alpha and beta emissions. 

Gamma spectrometry was ultimately the technique chosen to perform determinations of 226Ra 

and gross beta. 

Efforts were focused on finding a group chemical separation for thorium, uranium and 

polonium. Iron hydroxide coprecipitation was initially explored as a preconcentration technique 

but due to the possibility of high iron content in samples that would interfere with chemical 

separations and subsequent liquid scintillation measurements, the decision was made to use a 

manganese dioxide coprecipitation in reducing environment (i.e., to remove iron). A number of 

extraction chromatographic techniques were tested including a stacked TEVA-TRU followed by 

Sr Resin approach. Sr Resin is effective only for polonium and would be overwhelmed by 

barium resulting in low yields. Testing of the TRU Resin alone, however, showed excellent 

uptake of thorium, uranium, and polonium from a 4 M HCl load solution (containing ascorbic 

acid to reduce iron) and effective retention of the analytes during 4 M HCl rinse steps. Elution 

profiles (see Attachment 1, Figure 5) indicated that the three analytes could effectively be 

stripped from the column with 5 mL of ammonium bioxalate. Analysis of subsequent data 

indicated that a more complete recovery of analytes, especially uranium, was obtained by 

modifying the single 5-mL elution to five sequential 1-mL additions of bioxalate. 

Source preparation techniques were also investigated. A number of coprecipitation 

techniques were explored but obtaining quantitative coprecipitation for all three radioelements in 

a single step proved to be elusive. In the end, a simple technique was chosen - direct addition of 

the eluent to liquid scintillation cocktail. 

Pulse-shape discrimination liquid scintillation analysis is an attractive option because it 

was less sensitive to solids in the sample than gas flow proportional counting, has very high 

detection efficiencies due to the 4π counting geometry (~90%), and reasonably low backgrounds. 

The result was reasonably short count times (e.g., 30 minutes) and good detection capabilities. 

The final method for gross alpha (Th, U, and Po) by liquid scintillation was thus 

assembled based on the most successful approaches identified: manganese dioxide 

coprecipitation followed by group separation of thorium, uranium and polonium on TRU Resin, 

stripping with ammonium bioxalate, and pulse-shape discrimination liquid scintillation analysis. 

The draft method was tested using 230Th, 232U, and 209Po tracers and recoveries of ~89% and 

above were obtained for each of the three elements with 230Th, the test isotope selected for testing,

showing the lowest recoveries (See Attachment 1, Figure 6). 

Gamma spectrometry was selected for the 226Ra alpha measurement and the gross beta 

measurement. Beyond ensuring that solids remained suspended using an agar gelling technique, 

the classic technique for gamma spectrometry was used without significant modification. 

July - 2014 42 
July - 2014 43 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

No technical changes were made to the final measurement techniques following the 

initiation of development testing. Since the technical content of the method was finalized prior to 

Phase 2 and 3 testing, the data obtained in Phases 2 and 3 alone should be used reflect the 

performance of the final method as presented in Attachment III. 

The method validated for gross alpha by LSC measures the activity of isotopes of 

thorium, uranium and polonium. Alpha-emitting radium isotopes, which are likely to be more 

prevalent in these samples (in terms of activity concentration), could not be easily or 

economically incorporated into a single-step gross alpha method at this time. The uncertainty for 

alpha-emitting radium isotopes determined by gamma spectrometry is much larger than that for 

the liquid scintillation analysis for the other alpha-emitting isotopes.14 This result complicates the 

reporting process, and the determination of uncertainty, and prevents calculation of a single 

meaningful value for gross alpha detection capability. 

While radionuclide-specific determinations of the naturally occurring progeny of 

uranium and thorium decay chain members are possible by gamma spectrometry, the same 

differences in efficiency and abundance will result in counting times that are significantly longer 

than that for the alpha analyses. As mentioned in Section 1, gross alpha and beta activity is 

temporally dependent due to the inherent complexity of radioactive ingrowth and decay in the 

uranium and thorium decay chains. As a result of this, the physical activity of some of the 

radionuclides being measured will change over time such that the results at the beginning of an 

analysis sequence may not be comparable to those at the end of the run. Although the activity of 

long-lived radionuclides such as 226Ra would not be impacted, delaying count times for 

measurements of shorter-lived beta-emitters such as 212Pb, 214Pb, and 214Bi will have an impact 

on the activity measured. 

Overall the detection limits achieved, the MDC target and the action levels that were 

used were based on the results of the preliminary testing. These values were not as low as had 

originally been hoped for and can be improved upon with further analysis and development studies. 

Thus, two sets of recommendations follow for use of this method and possible further 

development. The first set of recommendations falls within the scope of the current method and 

possible improvements (recommendation 8) on it: 

1. Sample results using this method should be reported separately as:

a. Gross alpha (U, Th, Po) – LSC

b. Gross alpha (226Ra) – Gamma Spectrometry15

14 The magnitude of differences in uncertainty and counting time is attributable to the relative detection efficiency of liquid scintillation and 

gamma spectrometry instruments and differences in the abundance of decay particle emission rates (i.e., abundance) for the radionuclides. The 

detection efficiency of gamma spectrometry instruments is generally less than 10% of that for liquid scintillation counters. The abundance for 

gamma rays is often significantly less than 100%, but for radionuclides that decay by alpha emission the abundance is close to 100%. 

15 Combined gross alpha results provide no information about the radionuclides present. For example, it is not uncommon to find high levels of 

radium in FPWHFO samples even though there may be next to no U, Th, or Po present. By separately screening samples for Ra-226, and for 

alpha activity associated with U, Th, or Po, it may be possible to decide there is no need for radionuclide-specific testing for U, Th, or Po. This 

strategy can be used to streamline the characterization of samples. 
 

July - 2014 44 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

c.	 Gross beta – Gamma Spectrometry

2.	 In principal, a screening test should be designed to minimize the risk of not detecting analyte

present at the analytical action level to a rate that is acceptable in the decisionmaking

process. Low bias in a screening measurement may be tolerable as long as the criteria used to

decide that the analytical action level has been exceeded take into account uncertainty and

the bias associated with the measurement. Thus, additional work is needed to estimate the

bias and uncertainty associated with the Th, U, Po gross alpha measurement, and to propose

decision rules that ensure that measurements will reliably identify samples with activity that

exceeds the specified analytical action level.16

3.	 Although testing criteria were met, an observed low bias raises questions about the

ruggedness of the gross alpha measurement, especially with regard to analysis of FPWHFO

of different compositions, from different regions, or at different times in the hydraulic

fracturing life cycle. Future work should be done to explore the chemical separation scheme

to improve the individual recoveries for Th, U, and Po, and to test the approach using

FPWHFO of varying compositions such as will be encountered in samples resulting from

routine hydraulic fracturing operations.

4.	 Additional work is needed to validate the gamma spectrometry measurement for each of the

longer-lived beta-emitting members of the natural decay chains used to quantify gross beta

activity by gamma spectrometry (in addition to 228Ra).

5.	 Additional work is needed to optimize the data inputs (e.g., libraries), analysis parameters

(i.e., spectrum analysis parameters) and calculations used for the gamma spectrometry

analysis of 226Ra and radionuclides of interest to the gross beta analysis with a goal of

minimizing levels of bias and uncertainty in the measurement.

6.	 Additional work is needed to explore options for optimizing the preparation of the gamma

spectrometry sample so that the radioelements can be concentrated, thereby improving

measurement sensitivity and reducing the sample counting time.

7.	 Additional work would be needed if all four of the long-lived radioelements (Ra, U, Th, and

Po) associated with natural decay chain alpha-emissions are to be included in a single

separation and analysis.

8.	 Build on experience gained in this project in the area of chemical separations in FPWHFO

samples to develop sensitive radionuclide-specific testing methods including: 226Ra, 228Ra,

210Pb, 228Th, 230Th, 232Th, 238U, 235U, 234U, and 210Po.

The second set of recommendations has to do with temporally dynamic processes of 

radioactive decay and decay-progeny relationships is common to all gross alpha and beta 

16 See Appendix VI of Radiological Laboratory Sample Analysis Guide for Incidents of National Significance – Radionuclides in Water (EPA 

2008) for a discussion of the directed planning process (DQOs/MQOs) and guidance on controlling decision errors with analytical decision 

levels (ADLs). In this case, there is an additional concern about low bias in the measurement that must be worked out. 
July - 2014 45 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

measurements of natural decay chain radioactivity. As discussed above in Section 1, the activity 

of samples containing natural decay chain activity, especially 226Ra and 224Ra, changes over time 

due to radioactive ingrowth and decay processes. Specifically, the activity physically present in 

the sample test source and the interpretation of gross alpha and gross beta results, depend on the 

timing of processes preceding the sample collection, the elapsed time between sample collection 

and preparation, and the elapsed time between sample preparation and the count. Parameters that 

either must be controlled, or at least taken into consideration, to ensure reliable interpretation of 

results include: 

1.	 How long did FPWHFO fluids recirculate in the geologic formation prior to discharge to

a settling pond, basin or waterway?

2.	 Does the activity present in the FPWHFO at the time of the sample measurement reflect

that at key points in the life cycle of the FPWHFO (e.g., time of discharge, point of full

ingrowth, point of transport or release of fluids)?

3.	 How does the time elapsed between collection, preparation and counting of the samples

impact results. Can the timing of event be managed to minimize variability of results and

provide useful and intercomparable measurements for gross alpha and beta.

4.	 Does the use of 230Th or 210Po for LSC provide the best method isotope for gross alpha

activity?

5.	 The analysis of treated FPWHFO may prove to be a completely different matrix where

some radionuclides have been removed (e.g., Ra). Thus future work should also examine

these types of treated matrices.

Addressing these questions as part of the entire process, or identifying individual times for each 

of the separate steps until the laboratory receives the samples will ensure that the analytical 

results support defensible decisionmaking regarding the handling and disposition of the fluids. 
July - 2014 46 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

 

July - 2014 47 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

12.0 Summary and Conclusions 

Three parts of The Gross Alpha and Gross Beta Method in FPWHFO were tested using 

a matrix based on the composition of a FPWHFO sample received from the EPA to determine 

whether they would satisfy method development guidelines outlined in the Method Validation 

Guide for Qualifying Methods Used by Radiological Laboratories Participating in Incident 

Response Activities (EPA, 2009). Two of the three parts comprise measurements of alpha 

emitters in the sample while the third is designed to measure beta emitters. 

The MQOs for each of the three parts differed based on the matrix complexity, the 

instruments used for analyses, and the nuclear constants associated with the principal 

radionuclides used for the development process, and variation associated with preparation of the test 

samples. The as-tested MQOs and measured results are presented in Table 3. The final method 

with flow diagram used in this method development study is presented in Attachment III. 

Each of the three parts of the method validated met all of the acceptance criteria for 

method uncertainty as shown in Tables 6A, 6B, and 6C. A summary of the observed levels of 

uncertainty at each of three activity levels is summarized in Tables 7A, 7B, and 7C. Detectable 

levels of bias were observed across the activity levels for each of the three measurements as 

summarized in Table 10. The levels of bias, however, were so large that they compromised the 

determinatoin of method uncertainty. The detection capability for each of the three parts was 

successfully verified as summarized in 9A, 9B, and 9C. 

Although all testing criteria were met as described in this report, the complexity of 

the matrix prevented development of a single-measurement method for gross alpha and beta in 

FPWHFO samples that will be simple, economical, and sufficiently rugged in matrices beyond 

the one used for the testing. Performing this analysis required a level of effort that was much 

different from previous analytical methods in other water matrices for alpha or beta emitters. 

Several unique approaches were attempted in order to identify an analytical approach that would 

accommodate this particularly challenging matrix. Section 11 provides a brief synopsis of 

development activities and Attachment 1 provides additional detail supporting the method 

development activities preliminary to final testing. 

The final approach for gross alpha requires two measurements. The first measurement 

involves gross alpha by liquid scintillation counting following chemical separation to isolate 

thorium, uranium and polonium from the matrix. Method testing in the surrogate matrix indicates that 

a measureable bias is associated with the technique. Average recovery were 74±11% (k=1) of the 

known concentration of 230Th. Recoveries ranged from 57–104%. Although all of the testing

criteria were met, the observed low bias raises possible questions about the ruggedness of the 

technique, especially with regard to use of the method for analyzing of FPWHFO of different 

compositions, from different regions or different times in the hydraulic fracturing life cycle. 

Possible future work should be done to improve the ruggedness of the method and to develop 
 

July - 2014 48 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

estimates of uncertainty and decision criteria that would protect against decision errors using this 

screening technique.17 See Section 11 for recommendations for possible future work in this area. 

The second measurement for alpha activity associated with 226Ra is performed by 

gamma spectrometry. The gamma spectrometry measurement is used to simultaneously 

determine the activity of longer-lived members of the thorium and uranium decay chains for 

calculation of gross beta activity. Although the development process detected bias in the gamma 

spectrometry measurements at some levels, the magnitude of the bias is lower than that observed 

for the alpha and there is no need for concern about the ruggedness of the non-destructive 

measurement technique since there are no variables such chemical separations that will introduce 

variable levels of bias into the method. Section 11 suggests the possibility of future work to 

improve the sensitivity of the gamma spectrometry measurement. 

Due to the physics of the measurement technologies, radionuclide determinations 

performed by gamma spectrometry are generally less sensitive and have higher uncertainty that 

those performed by the liquid scintillation counting. This complicates the reporting process, the 

determination of uncertainty, and prevents calculation of a single meaningful value for gross 

alpha detection capability. Section 11 recommends that measurements of gross alpha by LSC and 

of 226Ra be reported and interpreted separately and suggests the possibility of future work that 

would improve the sensitivity of the gamma spectrometry measurement thereby minimize the 

disparity in the sensitivity of the two techniques. 

Finally, as mentioned in the introduction in Section 1, all gross alpha and beta measurements are 

limited by the complexities of radioactive decay and ingrowth in the uranium and thorium decay 

chains which causes the alpha and beta activity physically present in the sample to change over 

time. Thus gross alpha and beta measurements are often not (inter-) comparable from 

measurement to measurement or laboratory to laboratory. This significantly complicated the 

interpretation of gross alpha and beta results. Section 11 recommends that future work explore 

the impact of timing on the performance of the method and the interpretation of results, a project 

that would benefit gross alpha and beta measurements of natural products in all water matrices. 

17 A screening test should generally be designed to minimize the risk of not detecting analyte when it is present at some action level to a rate 

tolerable to the data end user. For this reason, screening tests tend to be structured to deliver results that systematically bias high. Low bias in a 

screening measurement may be tolerable as long as the criteria used to decide whether the action level has been exceeded take into account 

uncertainty and bias associated with the measurement. 
July - 2014 49 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

13. References

ASTM D7282 “Standard Practice for Set-up, Calibration, and Quality Control of Instruments 

Used for Radioactivity Measurements,” ASTM Book of Standards 11.02, current version, 

ASTM International, West Conshohocken, PA. 

ASTM D7283 “Standard Test Method for Alpha and Beta Activity in Water By Liquid 

Scintillation Counting,” ASTM Book of Standards 11.02, current version, ASTM 

International, West Conshohocken, PA. 

Multi-Agency Radiological Laboratory Analytical Protocols Manual (MARLAP). 2004. EPA 

402-B-1304 04-001A, July. Volume I, Chapters 6, 7, 20, Glossary; Volume II and Volume 

III, Appendix G. Available at www.epa.gov/radiation/marlap/. 

SM 7110C. “Coprecipitation Method for Gross Alpha Radioactivity in Drinking Water,” 

Standard Methods for the Examination of Water and Wastewater, current version, American 

Public Health Association, American Water Works Association, Water Environment 

Federation, APHA, Washington, DC. 

Taylor, John K. 1987. Quality Assurance of Chemical Measurements, Lewis Publishers, Chelsea, 

MI. 

U.S. Environmental Protection Agency (EPA), 1980. Prescribed Procedures for Measurement of 

Radioactivity in Drinking Water. Office of Research and Development, Environmental 

Monitoring and Support Laboratory, Cincinnati, OH. EPA 600/4-80-032. August. 

U.S. Environmental Protection Agency (EPA). 2006. Validation and Peer Review of U.S. 

Environmental Protection Agency Radiochemical Methods of Analysis. FEM Document 

Number 2006-01, November 8. 

U.S. Environmental Protection Agency (EPA). 2008. Radiological Laboratory Sample Analysis 

Guide for Incidents of National Significance – Radionuclides in Water. EPA 402-R-07-007, 

January. Available at: www.epa.gov/narel. 

U.S. Environmental Protection Agency (EPA). 2009. Method Validation Guide for Qualifying 

Methods Used by Radiological Laboratories Participating in Incident Response Activities. 

Revision 0. Office of Air and Radiation, Washington, DC. EPA 402-R-09-006, June. 

Available at: www.epa.gov/narel. 

U.S. Environmental Protection Agency (EPA). 2012. Quality Assurance Project Plan Validation 

of Rapid Radiochemical Methods For Radionuclides Listed in EPA’s Standardized Analytical 

Methods (SAM) For Use During Homeland Security Events. Revision 4. Office of Air and 

Radiation, National Analytical Radiation Environmental Laboratory. 
July - 2014 50 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 51 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Attachment I: 

Method Development Trials 

Classic Approach to Gross Alpha Beta: Evaporation and Gas Proportional Counting 

One ml of the field sample (no dilution or treatment) was evaporated directly onto a 

planchet. The dry weight was 260.3 mg and 276.4 mg for replicate samples. These values were 

well outside the efficiency calibration curves for either gross beta or gross alpha. Spattering of 

the material was significant which would lead to an underestimate of the count rate. Based on 

these two significant issues no further analysis by this method was deemed to be fruitful. 

Radionuclide: 226Ra 

Precipitation of BaSO4 to coprecipitate radium was tried once. It was evident that too 

much precipitate formed (other solids besides the barium/radium precipitate salt out and provide 

too heavy a matrix for gross analysis by GPC). The resulting precipitate could not be processed 

any further, even when small sample volumes (< 100 mL) were used. 

A more selective precipitation using barium chromate was attempted. This process 

yielded similar problems to using BaSO4 with a large mass of other salts precipitating, forming a 

black/green ‘dusty’ precipitate that could not be loaded onto a planchet for gas flow proportional 

counting. Using this material for liquid scintillation analysis yielded severe color quench18 . 

Radium recovery was only about 1%.19

Replicate aliquants of the sample (6×250 mL and 6×40 mL) were analyzed for 222Rn 

following a period for ingrowth to assess 226Ra concentration using a Durridge Rad7TM electric 

radon detector. This method provides high quality and consistent results, when the foaming of 

samples, relative humidity is controlled. Some issues where encountered with foaming of the 

FPWHFO samples. Methods could be developed for unsupported 222Rn/ 220Rn as well. The 

success of this approach indicates that a radon de-emanation approach to the analysis of 226Ra 

(direct analysis of 50 mL of sample without prior chemical concentration) would be capable of a 

reasonably sensitive determination of 226Ra with MDCs of ~10 pCi/L or less. The method would 

require waiting several days allowing the 222Rn to ingrow into the sample. This approach was not 

pursued further, however, because it would require significant additional development and would 

not provide the longer list of beta-emitting analytes possible for gamma spectrometry analysis. 

Radionuclides: U, Th, and Po 

A classical approach was attempted to obtain a gross separation of uranium and thorium 

by Fe(OH)3 precipitation. The iron hydroxide precipitate was dissolved in hydrochloric acid and 

loaded onto an Eichrom TRU/TEVA column for separation of the U/Th, and then eluted through 

a SR ResinTM for polonium. 

18 Quench refers to any process that reduces the production of, or transmission of light from the sample to the photomultiplier detector. If a 

correction cannot be applied, quench may result in questionable results. 

19 The recovery of 226Ra in this attempt was based on the analysis of the original sample for 226Ra by gamma spectrometry. 
July - 2014 52 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

In order to assess the success of the gross alpha attempts, the sample test sources were 

analyzed by alpha spectrometry. This not only helped to quantify yields but also to determine the 

effectiveness of separation of the alpha emitters. 

The recovery for the radionuclides was assessed using alpha spectrometry and was as follows: 

• Th recovery indeterminate due to 228Th ingrowth

• Po recovery ~29.6 ± 1.7%

• U recovery ~26-49 ± 11%

Po can be selectively electroplated onto a silver disk. However, it must be isolated first 

with SR ResinTM. Attempts to electrodeposit without a SR Resin clean-up resulted in no recovery 

with significant Th/Th-daughter contamination (as determined by alpha spectrometry). 

Figure 1 shows the alpha spectrum for the separated polonium (most abundant alpha in the 

spectrum at channel number ~ 950 is 4.88 MeV. 

Figure 1 – Po-209 Alpha Spectrum 
July - 2014 53 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Group Separation Using MnO2/Fe(OH)3 Precipitation 

This is a non-specific precipitation technique for radionuclide separation. The 

MnO2/Fe(OH)3 precipitate is dissolved in hydrochloric acid followed by TRU/TEVA group 

separation of actinides and SR-Resin for Po (U/Th). Run in quadruplicate. 

Adding MnO2 substantially increases recovery of U. Note that 228Th cannot be used as a 

tracer since it may be present in the sample as an ingrowth product from 228Ra; this provides an 

interesting possibility for dating of flowback waters. Natural 230Th and its parents are generally 

not detectable in samples. As such, 230Th may be a suitable candidate as a Th tracer for yield 

calculations. The U recovery for this mixed precipitate was 71.7±4.8%. 

Thorium recovery from the field sample was indeterminate due to 228Th ingrowth20

from 228Ra Analysis for either radium isotope was not attempted. When the surrogate solution 

was used with added 230Th tracer, the alpha spectrum in Figure 2 was obtained (the most 

abundant alpha at channel number ~ 970 is 4.688 MeV). 

Figure 2 – Alpha Spectrum of Separated 230Th 

20 Initially the concentration of 228Th may have been very low. However the age of the sample (at least 3 months) and the high concentration of 226Ra (determined by gamma spectrometry) have allowed significant ingrowth of the 228Th. 
July - 2014 54 

 

 

 

 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

EmporeTM RAD Disks 

This method of radionuclide concentration from water is used for several different 

radionuclides. The disadvantage is that disk material shows significant uptake of barium. 

Additionally, high concentrations of non-radionuclides, such as Ca and Sr, can outcompete Ra 

and significantly decrease retention on the disk. The recovery for radium was low, ~13.0 ± 1.1%, 

even with volumes as low as 50 mL of field sample diluted ten-fold to reduce the concentration 

of the non-radionuclide ions. There was too much competition for the exchange sites from nonradiological elements, and in particular for this sample, from barium. Therefore the use of the 

Empore disks was abandoned because of the significant non-radiological interfering ions. 

Direct Addition to LS Cocktail 

Addition of 0.10 to 10 mL aliquants of the field sample to liquid scintillation cocktail 

were used to determine the feasibility of performing direct gross alpha analysis. Even less than 

0.1 mL led to salting out in the cocktail yielding a two-phase mixture with a high quench. 

Although liquid scintillation measurement remained attractive, this experience indicated that 

analysis of the sample would only be possible after clean-up from the FPWHFO matrix (i.e., 

chemical separations). 

Gamma Spectrometry 

Gamma spectrometry was one of the first analyses to be performed to assess the level 

of beta-gamma-emitting radionuclides native to the sample. A 3-L Marinelli beaker was counted 

in three different manners: for 17 hours as a straight sample, for 6 hours as a straight sample, and 

for 17 hours with agar added to ensure that settling of suspended solids did not occur. 

226Ra and 228Ra (or their progeny) were detectable; however, no peaks were observed 

for 238U (234Th, 234mPa) or 235U or 228Th (224Ra). The low concentration of 235U in the sample, 

allowed for straightforward analysis of 226Ra using the 186 keV peak. 

Acid Digests Prior to Separations 

Gross alpha analysis was attempted using 10–100 mL of sample following digestion in 

nitric acid. However, the amount of residue formed from this digest clogged the TRU Resin 

preventing completion of preparation for analysis by alpha spectrometry. In the case of LSC, the 

final digestate resulted in unacceptably high amounts of color quench. 

Platinum Crucible 

Initially acid digestion or fusion techniques were considered as an initial step in the 

process. The quantities of dissolved solids in the field sample limit the size of the aliquant 

making the fusion method using platinum crucibles unfeasible. 

Polonium by Sulfide Precipitation 

A method of isolating polonium from the bulk solution used CuS precipitation under 

acidic conditions was attempted as PoS will coprecipitate with CuS. Figure 3 shows the liquid 

scintillation spectrum from that gross separation. However, this separation technique was not 
July - 2014 55 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

used in the final method as it caused an unacceptable level of quench in the liquid scintillation 

spectrum which would degrade the measurement sensitivity and reliability of the method. 

Figure 3 – Liquid scintillation Spectrum of 209Po 

While this separation technique was fairly specific for polonium, the low yield and the 

quantity of salts (high quench) made this separation technique undesirable. 

Thiacalix Resins 

Thiacalix resins initially appeared to be a possibility for 226Ra separation since they are 

the most selective of Ra resins. However at a Ba: Ra mass ratio of 104, recovery drops to 20%. 

The field sample obtained had a mass ratio for Ba: Ra of 109

. Furthermore, these resins 

experience interference from other divalent cations such as Mg, Ca, Sr, which are present in 

similar concentrations to Ba in our sample. Therefore this method of radium separation was not 

used. 

Flow Chart for the Alpha Beta Methods Attempted 

Figure 4 shows the flow chart for the methods attempted for the analysis of gross alpha 

and gross beta. In this instance, tracers were used with the surrogate solution to assess the 

viability of these separations. The combined iron hydroxide manganese dioxide precipitate, 

combined with the elution of the dissolved precipitate through a TRU column provided a good 

separation of the alpha emitters uranium, polonium and thorium. Figure 5 shows that with a few 

milliliters of bioxalate solution (0.1 molar), the major alpha contributors are eluted together. 
July - 2014 56

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Figure 6 shows the recovery of three radioelements (U, Th, Po) using the optimized method prior 

to method testing. 

Figure 4 – Flow Chart for Method Development Using Tracers 

 

 

 

 

 

Gross Alpha Analysis 

300 mL original sample, filtered and 

acidified, 209Po, 232U, 230Th 

Add tracers natU, 230Th, 209Po Dilute to 500 mL, boil – 60 min 

MnO2 :Th + U +Po precipitates 

Dissolve precipitate in 10 mL 6 

N HCl + 2 mL 1.0 N ascorbic 

acid. 

Add 29 mg KMnO4, boil,+ 6 N 

NH4OH, to pH 7.0 

1. 

Load solution. 

Discard waste. 

Discard supernatant and 

wash solutions 

2. 

Rinse with 3 5-mL portions 

4 N HCl. 

Discard waste. 

Load HCl solution 1 mL/min, 

onto TRU resin 

Discard residue. 

Filtrate 

Gross Beta Analysis 

3 – 4 L of original sample, 

filtered and acidified 

Direct Gamma 

Spectrometry Measurement 3. 

Elute with 10-mL 0.1 M 

(NH4)2Ox 

Th, U, Po+2, Po+4 

Ce(OH)4 (or CeF4) 

microprecipitation Alpha Spectrometry 

214Pb, 212Pb, 214Bi, 212Bi, 210Po 226Ra 234mPa, 228Ra, 210Bi, 212Bi 

Gross Beta 

Add tracers 

226Ra and 228Ra 

Inferential 

Determination 

Figure 5 – Elution Profile for Traced solution with 0.1 M Ammonium Bioxalate in 4 M HCl 
July - 2014 57 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Figure 6 – Total Recovery of Tracers (%) with (0.1 M Ammonium Bioxalate in 4 M HCl) 

Note: These elutions were performed with 5 -1 mL (blue) volumes or 1- 5 mL volume (red). 

0

10

20

30

40

50

60

70

80

90

100 

Polonium Uranium Thorium 

5x1 mL

1x5 mL 

These final results of the tracer trials provided evidence that the proposed methods of 

chemical separation for the gross alpha (for Th, U, and Po) would be successful. 
July - 2014 58 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 59 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

Attachment II: 

Time Lapse 

Table 11 – Estimated Elapsed Times for Gross Alpha Analysis 

Gross Alpha Analysis Step Time for 1 Sample (min.) Time for Batch of 20 (min.) 

Measure aliquant, take “initial” volume 

of sample 2 20

Precipitation and removal of 

supernatant 90 200

Redissolution 5 50

Loading and elution of sample through 

TRU Resin 30 300

Perform eluate transfer to LSC vial 2 20

Count samples (maximum count time) 30 600* 

Data analysis and review 20 300

Total Time 179 1490 

*Assumes only one LSC unit is used 

Table 12 – Estimated Elapsed Times for Gross Beta Analysis 

Gross Beta Analysis Step Time for 1 sample (min.) Time for Batch of 20 (min.) 

Measure aliquant, take “initial” volume 

of sample 4 40

Count samples (maximum count time) 720 14400* 

Data analysis and review 20 300

Totals 744 14740 

*Assumes only one gamma-ray spectrometer is used. 
July - 2014 60 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 61 

Attachment III: 

Rapid Radiochemical Method for Gross Alpha and Gross 

Beta Activity in Flowback and Produced Waters from 

Hydraulic Fracturing Operations (FPWHFO) 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

1. Scope and Applicability

1.1.	 This method was developed for flowback and produced water from hydraulic

fracturing (FPWHF) operations. This type of sample will contain several 

radionuclides from any of the three natural decay chains. However, based on the 

variability in of chemical compounds in the fracturing fluid, the geologic formation 

that is being developed and other environmental factors, no assumptions about 

radioactive equilibrium should be made when performing the analyses. 

1.2.	 The following alpha and beta activity is determined in this method: 

1.2.1.	 All alpha radioactivity in a hydraulic fracturing sample is associated with 

naturally occurring uranium, thorium and radium, short-lived progeny of 

these radioelements, and 210Po. The gross alpha screen is accomplished with 

two measurements. 

1.2.1.1.	 The first involves a group separation of U, Th, and Po followed by 

liquid scintillation counting for gross alpha. This approach 

quantifies gross alpha activity associated with uranium isotopes 

(

238U, 235U , 234U), thorium isotopes, (232Th 230Th , 228Th), shortlived progeny from 228Th as may have ingrown following the 

separations, and 210Po. 

1.2.1.2.	 A non-destructive gamma spectrometry screen is used to determine 

alpha-emitting radium activity, primarily associated with 226Ra. 

1.2.1.3.	 The results of the two measurements may be used, either 

individually, or the measurements may be mathematically summed 

and their uncertainties combined to yield an estimate the combined 

gross alpha activity of the sample. 

1.2.2.	 Gross beta screening is accomplished by gamma spectrometry measurement 

of radium isotopes (226Ra, 228Ra, 224Ra) and other gamma-emitting natural 

chain radionuclides. The beta activity of Ra and its short-lived progeny 

(assuming equilibrium ingrowth) are summed and uncertainties combined to 

yield a result for the gross beta screen. 

1.2.3.	 The gamma spectrometry measurement also achieves a definitive 

determination of the isotopic activity of gamma-emitting tracers used to 

assess the efficacy of the hydraulic fracturing process that have not decayed 

between collection and the gamma spectrometric measurement. 

1.3.	 The gross alpha and beta screening results are not corrected for decay. 
July - 2014 62 

1.4.	 The method is not intended to demonstrate compliance with the requirements of the 

Safe Drinking Water Act (SDWA). 

1.5.	 FPWHFO matrices may contain different chemical mixtures. Method validation may 

need to be performed for mixtures that significantly differ in composition from a fluid 

matrix that has been previously validated. 

1.6.	 The method is capable of achieving the following MQOs: 

1.6.1. Gross alpha screen consisting of the following two components: 

1.6.1.1.	 Gross Alpha by liquid scintillation counting for Th, U, and Po and 

decay progeny. A 300 mL sample can achieve a required method 

uncertainty of 9.0 pCi/L at less than or equal to an Analytical 

Action Level (AAL) of 40 pCi/L. This result is referenced to the 

radionuclide used for calibration of the detection system, 230Th, or

210Po. 

1.6.1.2.	 226Ra alpha by gamma spectrometry: A 3.0 L sample can achieve a 

required method uncertainty of 33% (relative), at less than or equal 

to an AAL of 165 pCi/L. 

1.6.2.	 228Ra beta by gamma spectrometry: A 3-L sample can achieve a relative 

required method uncertainty of 50%, at less than or equal to an AAL of 60 

pCi/L. 

1.6.3.	 Application of the method must be validated by the laboratory using the 

protocols provided in Reference 16.1. The sample turnaround time and 

throughput may vary based on additional project MQOs, the time for 

analysis of the final counting form and initial sample volume. 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 

2. Summary of Method

2.1. See Section 17.4 for a flow chart overview of the process.

2.2. Gross Alpha

2.2.1.	 The sample is treated with potassium permanganate and ammonia to 

coprecipitate radionuclides. The alpha emitting radionuclides are separated 

using a TRUTM resin. The activity of the eluate from the resin is determined 

using a liquid scintillation counter. 

2.2.2.	 Ra-226 is determined by direct counting of the 186 keV photopeak using 

gamma-ray spectrometry. It may also be used to determine the activity of its 

beta-gamma emitting progeny. 

2.3. Gross Beta 

2.3.1.	 A 3L aliquant of the sample is counted directly using gamma ray 

spectrometry. Gross beta activity is determined by summing the gamma 

emitters activity plus those beta only-emitters that are progeny or parents of 

gamma emitters detected with less than 50% relative CSU (see Step 2.2.2 

and 2.3.2). 
July - 2014 63 

2.3.2.	 Ra-228 is determined by direct counting of the 911 or 338 keV photopeak 

using gamma ray spectrometry. 

3. Definitions, Abbreviations and acronyms

3.1.	 Analytical Protocol Specifications (APS). The output of a directed planning process

that contains the project’s analytical data needs and requirements in an organized, 

concise form. 

3.2.	 Analytical Action Level (AAL). The term “analytical action level” is used to denote 

the value of a quantity that will cause the decision maker to choose one of the 

alternative actions. 

3.3. Flowback and Produced Water from Hydraulic Fracturing (FPWHF) Operations. A 

fluid used when gas or oil is extracted from shale rock formations. The produced 

water from fracking operations contains up to 200 different chemicals that comprise 

the solution, plus any minerals that are extracted from the shale formation during the 

process. Each type of FPWHF may be unique in its chemical and physical properties. 

3.4.	 Multi-Agency Radiological Analytical Laboratory Protocols Manual (MARLAP) (see 

Reference 16.2). 

3.5.	 Measurement Quality Objective (MQO). The analytical data requirements of the data 

quality objectives that are project- or program-specific and can be quantitative or 

qualitative. These analytical data requirements serve as measurement performance 

criteria or objectives of the analytical process. 

3.6.	 Required Method Uncertainty (uMR). The required method uncertainty is a target value 

for the individual measurement uncertainties and is an estimate of uncertainty (of 

measurement) before the sample is actually measured. The required method 

uncertainty as an absolute value is applicable at or below an AAL. 

3.7.	 Relative Required Method Uncertainty (φMR). The relative required method 

uncertainty is the uMR divided by the AAL and is typically expressed as a percentage. 

It is applicable above the action level. 

3.8.	 Sample Test Source (STS). This is the final form of the sample that is used for 

nuclear counting. This form is usually specific for the nuclear counting technique in 

the method, such as a solid deposited on a filter for alpha spectrometry analysis. 

4. Interferences

4.1.	 Radiological:

4.1.1.	 The elapsed time between sampling and arrival at the laboratory and the 

start of the analytical process to the counting time should be recorded for 

each sample. These time frames can have significant effects on the final 

activity concentrations determined. This is due to the various radiochemical 

equilibria that exist for the naturally occurring radionuclides. It will be 

important for the laboratory to know at which point in time (e.g., sample 

time, arrival at laboratory, time of discharge) the client desires to have the 

activity concentrations corrected to so that they can meet the needs of the 

project. 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

4.2. Non-radiological: 

4.2.1.	 FPWHFO samples will be high in dissolved solids content as well as having 

a high concentration of other ionic substances not usually encountered in 

surface or drinking water samples (e.g., barium, strontium, and silica). 

4.2.2.	 Although the method has been designed to accommodate high levels of 

solids, including Group II elements, concentrations of non-radioactive 

barium in the grams/L range may require a decreased sample size (i.e., 

smaller) to be selected. 

4.2.3.	 Similarly, high concentrations of non-radioactive calcium, magnesium or 

strontium in the sample may require the use of a decreased sample size. 

5. Safety

5.1. General

5.1.1.	 Refer to your safety manual for concerns of contamination control, personal 

exposure monitoring and radiation dose monitoring. 

5.1.2.	 Refer to the laboratory chemical hygiene plan for general chemical safety 

rules. 

5.2. Procedure-Specific Non-Radiological Hazards: 

5.2.1.	 Solutions of potassium permanganate can rapidly oxidize organic materials 

and generate significant heat. Do not mix large quantities of permanganate 

solution with solutions of organic solvents as the potential for conflagration 

exists. 

6. Equipment and Supplies

6.1. Toploader balance with a 0.1-g readability.

6.2. Beakers, Pyrex®: 250, 400 mL.

6.3. Centrifuge capable of holding 300 mL vessels (optional).

6.4. Hot plate, or other suitable device for heating ammoniated sample volume.

6.5. Glass stirring rods.

6.6. Graduated cylinders: 500, 1000, 4000 mL capacities.

6.7. Scintillation vials: 22 mL glass.

6.8. pH paper; range 5.0–9.0 pH units.

7. Reagents and Standards

NOTES: All reagents are American Chemical Society (ACS) reagent grade or equivalent unless otherwise 

specified. 

Unless otherwise indicated, all references to water should be understood to mean Type I Reagent water (ASTM 

D1193, Reference 16.3). 

7.1. Potassium Permanganate, (KMnO4) 

7.2. Ammonium Hydroxide (NH4OH): Concentrated (15 M) 

7.2.1.	 Ammonium Hydroxide (NH4OH): (6 M); dilute 40 mL of concentrated 

ammonium hydroxide to 100 mL with water. 

July - 2014 64 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
7.3.	 Hydrochloric Acid (HCl): Concentrated (12 M) 

7.3.1.	 Hydrochloric Acid (HCl): (6 M); dilute 50 mL of concentrated hydrochloric 

to 100 mL with water. 

7.3.2.	 Hydrochloric Acid (HCl): (4 M); dilute 33 mL of concentrated hydrochloric 

to 100 mL with water. 

7.4.	 Ascorbic Acid, crystals 

7.4.1. Ascorbic Acid (1 M); dissolve 176 g of dried crystals in 100 mL of water 

7.5.	 Ammonium Bioxalate, crystals 

7.5.1.	 Ammonium Bioxalate (0.1 M); dissolve 12.4 g of dried crystals in 100 mL 

of demineralized water 

7.6.	 UltimaGold ABTM scintillation cocktail, (available from PerkinElmer Inc.) or 

equivalent. 

7.7.	 TRU ResinTM (Eichrom Technologies, LLC.); 100-150 micron 

7.8.	 Calibration sources, Traceable to a national standards body such as the National 

Institute of Standards and Technology (NIST) in the U.S. 

7.8.1.	 For liquid scintillation: 230Th or 210Po in a counting configuration that 

matches that of the sample test source as closely as possible. If sample 

quench varies enough that the efficiency varies by more than 10%, prepare 

standards with varying levels of quench that span the range of efficiencies 

encountered during the analysis of samples. 

7.8.2.	 For gamma spectrometry: Either 228Ra and 226Ra or a mixed gamma source 

with energies spanning the entire range of energies to be used during 

analysis of samples. The geometry of the calibration standard shall match 

that of the sample test source as closely as possible (e.g., Marinelli beaker 

3000-mL volume, density, average “z”, etc.). See Section 11.1.3 for a 

description of preparation of the sample test source. 

8. Sample Collection, Preservation and Storage

8.1.	 None recommended

9. Quality Control

9.1.	 Batch quality control results shall be evaluated and meet applicable Analytical Project

Specifications (APS) prior to release of unqualified data. In the absence of projectdefined APS or a project-specific quality assurance project plan (QAPP), the quality 

control sample acceptance criteria defined in the laboratory quality manual and 

procedures shall be used to determine acceptable performance for this method. 

9.2.	 A laboratory control sample (LCS) shall be run with each batch of samples. The 

concentration of the LCS should be at or near the action level or a level of interest for 

the project. 

9.3.	 One method blank shall be run with each batch of samples. The laboratory blank 

should consist of demineralized water. 

July - 2014 65 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
9.3.1.	 If possible a matrix blank that includes a surrogate solution made from 

reagent grade chemicals should be analyzed. 

9.4.	 One laboratory duplicate shall be run with each batch of samples. The laboratory 

duplicate is prepared by removing an aliquant from the original sample container after 

mixing/stirring. 

9.5.	 A matrix spike sample may be included as a batch quality control sample if there is 

concern that matrix interferences, such as the presence of elemental barium in the 

sample, may compromise chemical yield measurements, or overall data quality. 

9.5.1.	 Matrix spike added activity may be difficult to estimate unless there is prior 

historical data to identify an existing concentration of some of the 

radionuclides. 

10. Calibration and Standardization

10.1.	 The liquid scintillation counter is set-up, calibrated, verified, quality controls

performed according to manufacturer’s specifications for alpha/beta discrimination, 

and as specified in ASTM D7282 Sections 9, 12, 13, 19, and 25. 

10.1.1.	 Set up the scintillation counter to discriminate between alpha and beta 

pulses according to manufacturer’s specifications. Samples are counted in 

an energy window that encompasses the alpha peak observed in the middle 

section of the alpha spectrum. 

10.1.2.	 Calibrate the LSC for alpha efficiency in the same energy window of the 

alpha spectrum used to count samples. 

10.1.3.	 Use standard 230Th or 210Po incorporated in the same counting configuration 

used for samples (i.e., vial type, cocktail, chemical make-up of the aqueous 

matrix, sample to cocktail ratio, and quench levels should match that of the 

samples as closely as possible). See Sections 11.1.2.9 and 11.1.2.10 for a 

description of preparation of the sample test source. 

10.1.4.	 The subtraction background is determined in the same energy window of the 

alpha spectrum used to count samples using a background sample that 

matches that of samples being analyzed. 

10.2.	 The gamma spectrometer is set-up, calibrated, verified, quality controls performed 

according to manufacturer’s specifications for alpha/beta discrimination, and as 

specified in ASTM D7282 Sections 9, 12, 13, 17, and 23. 

10.2.1.	 Calibrate the gamma spectrometer across the entire energy range to be used 

during analysis of samples. 

10.2.2.	 Count the calibration standard (Section 7.1.2) in the same juxtaposition to 

the detector as the samples. 

11. Procedure

11.1.	 Water Sample Preparation

11.1.1.	 A well-mixed portion of the sample is taken for each of the separate analysis 

flow paths: 

NOTE: The sample is not filtered. 

July - 2014 66 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

11.1.1.1. 300 mL for gross alpha analysis 

11.1.1.2. 3.0 L for gamma spectrometry analysis 

11.1.2.	 Gross Alpha Analysis 

11.1.2.1. Add 29 mg of KMnO4 and bring the solution to a boil. 

11.1.2.2. Add enough concentrated ammonium hydroxide to bring the 

solution into a pH range of 5.0 to 9.0. 

11.1.2.3. Dilute the solution to 500 mL with demineralized water and bring 

to a boil for approximately 60 minutes. 

11.1.2.4. When the solution has cooled, and settled, decant off and discard 

the supernatant solution 

11.1.2.5. To the residue after decantation add approximately 10 mL of 6 M 

HCl and 2 mL of 1.0 M ascorbic acid. 

NOTE: this is the load solution for the solid phase extraction column and 

should be kept to a minimum. Fresh ascorbic acid should be used to ensure 

all the Fe+3 have been reduced to Fe+2 . 

11.1.2.6.	 Load the solution in 11.1.2.5 onto a TRU Resin column at the 

rate of 1 mL/min 

11.1.2.7.	 Discard the eluate from the load solution 

11.1.2.8.	 Rinse the TRU Resin column with three 5-mL portions of 4M 

HCl at a flow rate of 1 mL/min. Discard the wash solutions. 

11.1.2.9.	 Elute the radionuclides using 10 mL of 0.1 M ammonium 

bioxalate solution 

11.1.2.10. Add the entire eluate to 15 mL of UltimaGold AB cocktail in a 

22-mL scintillation vial. This is the sample test source (STS) for 

the gross alpha measurement. 

11.1.2.10.1.	 Liquid Scintillation Counting 

After dark adaptation, the sample is counted for 

approximately 30 minutes or long enough to meet 

the MQOs noted in Step 1.6. 

11.1.3.	 Determination of Gross Beta and Radium 226 activity by gamma 

spectrometry 

11.1.3.1.	 If necessary to prevent settlement of solids during the counting 

time either: 

11.1.3.1.1.	 Acidify the solution with 16 M nitric acid until 

solids dissolve, or 

11.1.3.1.2.	 Add sufficient agar to suspend any solid materials. 

11.1.3.2.	 Count the sample on a gamma ray spectrometer for 

approximately 6–12 hours or until the MQO’s noted in Step 1.6 

can be achieved. 

NOTE: The exact time to count the sample will depend upon the exact sample size taken and the 

efficiency of the detectors used for the analysis. In either case the counting time should be 

adjusted so that the MQOs noted in Step 1.6 can be achieved. 

11.1.3.3.	 Using the information in Figure 17.1: 

July - 2014 67 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

12. Data Analysis and Calculations

12.1. Results are reported as gross alpha 

12.1.1. 

ݕݐ݅ݒ݅ݐܿܣ ݄ܽ݌݈ܣ ݏݏ݋ݎܩ

a

,

nd gross beta activity as f

ൌ

ollows: 

Gross Alpha Activity 

Where: 

௅ௌ஼

௣஼௜ ሺ௖௣௠

௅ ሺ௏ൈଶ.ଶଶൈ

ೞି௖௣௠

ఢሻ

್ሻ (1)

cpms is the sample gross count rate, in counts per minute 

cpmb is the instrument background count rate in counts per minute 

 ε is the detector efficiency based on the instrument quench curve and a 

230 

Where: 

ݏݏ݋ݎܩ

Th or 210

 V is the sam

ݕݐ݅ݒ݅ݐܿܣ ݄ܽ݌݈ܣ 

Po calibration source 

ple volum

௚௔௠௠

e used in liters 

௔ ௦௣௘௖,

௣஼௜

௅ 

I are the individual radium alpha em

ൌ

itter ac

∑ଵ

௡ሺܫఈିఊሻ௡ (2)

α-γ tivities inferred from 

12.1.2. Gross Beta Activity 

 Where: 

ݏݏ݋ݎܩ

gamma-em

௖௘௣௦௚௔௠௠௔ ݕݐ݅ݒ݅ݐܽܿ 

M is the activity of each measured

ܽݐܾ݁ 

itting counterparts (usually only 226

, ൌ 

Ra) 

௣஼௜ ௝

௅ ∑ ଵሺܯఊሻ௝ ൅ ∑ଵ

௞ሺܫఊ

γ a-ray em

ሻ௞ (3)

 gamm itting radionuclides 

 Iγ are the activities of the non-gamma, beta- emitting radionuclides that 

 are inferred. 

12.1.3. Measurement uncertainty 

NOTE: The uncertainty for the indirectly measured radionuclides should be made equal to the 

uncertainty from their gamma-emitting parent or progeny (for either the alpha-only or beta 

only emitters). Since this is a gross analysis this approximation should be satisfactory. 

12.1.3.1. Gross alpha 

11.1.3.3.1.	 Determine which radionuclides that are to be 

inferentially determined will be in secular 

equilibrium based on the time between sampling 

and analysis. 

11.1.3.3.2.	 Sum the activities of the radionuclides that have a 

CSU of less than 50% and those inferred assuming 

secular equilibrium. 

11.1.3.3.3.	 Review the gamma-ray spectrum report for any 

gamma rays that are unidentified and ascribe 

identities to them. 

Determine if these activities need to be added to 

the sum in Step 11.1.3.3.2. 

11.1.3.3.4.	 The gross beta activity is estimated by the sum of 

Steps 11.1.3.3.2 and 11.1.3.3.3 (See Section 12) 

July - 2014 68 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 69

 ൌ ݏ1 , ݕݐܽ݅݊ݐݎܷ݊ܿ݁ ݄ܽ݌݈ܣ ݏݏ݋ݎܩ

൜

೎೛೘ೞା೎೛೘ ൠ

భ/మ ್ 

௅ௌ஼ ሺ

೟ೞ 

ଶ.ଶଶൈఢ

೟್ 

ට ൌ ݏ1 , ݕݐܽ݅݊ݐݎܷ݊ܿ݁ ݄ܽ݌݈ܣ ݏݏ݋ݎܩ

ൈ௏ሻ (3)

Where:

௚௔௠௠௔ ௦௣௘௖ ∑ଵ

ூݑ ௡

ଶ

ഀష

೙ ം (4)

ݑூഀష

೙ ം is the uncertainty of an individual gamma emitter that is used to determine the 

alpha activity. 

12.1.3.2. 

 

ݏݏ݋ݎܩ

Where: 

ܽݐ݁ܤ 

Gross Beta

 ܷ݊ܿ݁ݐݎܽ݅݊ݕݐ ௔௠௠௔௚௦௣௘௖, 1ݏ ൌ ට∑ଵ

ଶݑ൤ ௞,௝

ெം ௝ 

ଶݑ ൅

ூം ௞

൨ (5) 

ݑெം ௝ ൌ

and

ݏ݈ܿ݅݀݁ݑ݊݋ܽ݀݅ݎ ݁݀ݎݑݏ݉݁ܽ ݕ݈ݐ݁ܿݎ݀݅ ݎ݋݂ ݐݎ݋݌݁ݎ ݉ݑݎݐ݁ܿ݌ݏ െ ߛ ݉݋ݎ݂ ߪ 1

ݎ݋݂ ூݑ

(6)

 (7) ം௞

13. Method Performance

ݏ݈ܿ݅݀݁ݑ݊݋ܽ݀݅ݎ ݁݀ݎݑݏ݉݁ܽ ݕ݈ݐ݁ܿݎ݅݊݀݅ ߪ 1 ൌ

13.1. Results of method validation performance are to be archived and available for

reporting purposes. 

13.2. Expected turnaround times are: 

13.12.1 Gross alpha ~3 hours for an individual sample and ~25 hours per batch 

(see Section 17.2). 

13.12.2 Gross beta ~13 hours for an individual sample and ~10 days per batch (see 

Section 17.3). 

14. Pollution Prevention

14.1.	 The use of potassium permanganate to produce MnO2 and a TRU® resin reduces the

amount of solvents that would otherwise be needed to co-precipitate and purify the 

final sample test source. 

14.2.	 Ultima Gold AB is a non-hazardous waste after it is used. 

15. Waste Management

15.1.	 Nitric acid and hydrochloric acid wastes should be neutralized before disposal and

then disposed of in accordance with local ordinances. 

16. References

16.1.	 U.S. Environmental Protection Agency (EPA). 2009. Method Validation Guide for

Radiological Laboratories Participating in Incident Response Activities. Revision 0. 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

 

 

 

 

 

 

 

 

 

 

Office of Air and Radiation, Washington, DC. EPA 402-R-09-006, June. Available 

at: www.epa.gov/narel/incident_guides.html. 

16.2. Multi-Agency Radiological Laboratory Analytical Protocols Manual (MARLAP). 

2004. EPA 402-B-1304 04-001A, July. Volume I, Chapters 6, 7, 20, Glossary; 

Volume II and Volume III, Appendix G. Available at: www.epa.gov/radiation/ 

marlap/index.html. 

16.3. ASTM D1193, “Standard Specification for Reagent Water,” ASTM Book of 

Standards 11.02, current version, ASTM International, West Conshohocken, PA. 

16.4. NNDC, Brookhaven National Laboratory, sonzogni@bnl.gov. 

16.5. Data Source: National Nuclear Data Center, Brookhaven National Laboratory, based 

on ENSDF and the Nuclear Wallet Cards (2014); http://www.nndc.bnl.gov/chart/. 

16.6. ASTM D7282 “Standard Practice for Set-up, Calibration, and Quality Control of 

Instruments Used for Radioactivity Measurements,” ASTM Book of Standards 11.02, 

current version, ASTM International, West Conshohocken, PA. 

17. Tables, Diagrams and Flow Charts

17.1. Table of Direct and Inferential Determinations for Gamma Ray Emitters

Radionuclide Gamma Ray 

Energy, keV Abundance,% Half-Life, Days 

Time from 

Sampling to 

Counting, 

Days 

Inferred 

Activity 

208Tl [1] 583 85.0 2.1×10-3 < 0.1 212Bi 

210Pb 46.5 4.25 8.1×10+3 365 210Po 

30 210Bi 

212Pb 238 43.6 4.4×10-1 2 224Ra 

212Bi 727 6.67 4.2×10-2 2 224Ra 

214Pb 295 18.4 1.9×10-2 18 226Ra 

352 35.6 1.9×10-2 18 226Ra 

214Bi 609 45.5 1.4×10-2 18 226Ra 

1120 14.9 1.4×10-2 18 226Ra 

226Ra [2] 186 3.64 5.8×10+5 — —

228Ac 338 11.3 2.6×10-1 1.5 228Ra

911 25.8 2.6×10-1 1.5 228Ra 

234Th 93 4.2 2.4×10+1 < 0.1 234mPa 

63 3.7 2.4×10+1 < 0.1 234mPa 

[1]	 Tl-208 also has a gamma at 2615 keV that is 99% abundant. 

[2]	 Note that this gamma ray is interfered with by the gamma ray from 235U at 185. The 226Ra can be determined directly if no 235U is present or 

if the 235U peak issued to subtract out the interference at 186 keV. See Reference 16.5. 

July - 2014 70 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

 

17.2. Estimated Elapsed Times for Gross Alpha Analysis 

Gross Alpha Analysis Step Time for 1 Sample, Minutes Time for Batch of 20, Minutes 

Measure aliquant, take “initial” 

volume of sample 2 20

Precipitation and removal of 

supernatant 90 200

Redissolution 5 50

Loading and Elution of sample 

through TRU resin columns 30 300

Perform eluate transfer to LSC vial 2 20

Count samples (maximum count 

time) 30 600* 

Data analysis and review 20 300

Total Time 179 1,490 

*Assumes only one LSC unit is used.

17.3. Estimated Elapsed Times for Gross Beta Analysis 

Gross Beta Analysis Step Time for 1 Sample, minutes Time for Batch of 20, minutes 

Measure aliquant, take “initial” 

volume of sample 4 40

Count samples (maximum count 

time) 720 14,400* 

Data analysis and review 20 300

Totals 744 14,740 

*Assumes only one gamma ray spectrometer is used.

July - 2014 71 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 72 

17.4. Sample Processing for FPWHFO 

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
July - 2014 73

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity in FPWHFO 
 

 

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