Estimation of Radionuclides in Sand and Soil Samples in the United States, 2014


eagerlabassistants.com


March 7, 2015

Summary: The findings of this report are the results of gamma spectroscopy tests to detect presence and estimate activity of both natural radiation and potential radioactive contaminants in soil and sand samples collected in 2014 across the United States. Uranium-238 activity was estimated <50.0 - 233.6 Bq/kg, Thorium-232 estimates of activity, if present, were approximately 20 – 110 Bq/kg, Potassium-40 ranged from 57.3 - 345.5 Bq/kg, Cesium-137 activity levels ranged from 3.6 - 20.3 Bq/kg, Cesium-134 levels ranged from approximately 1.2 - 3.4 Bq/kg with detections at other energy levels included.


Objectives: The objectives of this study are several-fold: to act as successor to the study Estimation of Cesium in Sand and Soil Samples in the United States, 2012-2013 in establishing baseline data on levels of cesium in soil; to broaden the geographical scope of the investigation through sampling location in addition to increasing the number of measurements made for a more in-depth analysis of each sample; serving as a reference in documenting changes to environmental radioactivity due to anthropogenic activities; and to serve as a data set for use in current and future analyses.
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Sample Locations, Sites and Collection: Sample locations depended entirely on several citizen scientists' locations, travels and willingness to collect and donate samples for this study. In that respect, they can be considered randomly collected; however, sample site within a given location cannot be considered random. In addition to careful consideration to avoid contamination, sample collectors were instructed to gather any pertinent notes, choose to collect from the most undisturbed ground they could find in the sampling location, request permission should it be applicable and, if possible, collect from the top 1” of soil to maintain consistency in samples with the previous study as well as meet the conditions to have the best opportunity to collect any potentially recent deposition. In all cases the formers were achieved to the best of our knowledge and any deviation from the latter is noted in the sample notes towards the end of this study. Many thanks is deserving to the several citizen scientists for collecting, sharing and permitting these samples - also performed by citizen scientists.

     Figure 1

     Figure 3

Soil and sand samples were obtained between March and September of 2014 from every designated region in the continental United States. Totals consist of 57 soil samples and 3 sand samples as denoted on the map above (see Figure 1). Each sample upon collection or receipt was assigned a sample number, placed in a standardized cylindrical jar, labeled, weighed, tested with an Inspector Geiger counter and sealed (see Figure 2). The samples were then stored for at least 3 weeks prior to testing with a GS2812 NaI(Tl) scintillator and a GS1100A multichannel analyzer using PRA8.0 software to determine the presence of radiation through gamma spectroscopy. The scintillator was calibrated with a cesium-137 NIST standardized check source and a cobalt-60 check source before eight (8) hour tests with accompanying and interspersed regular background tests were conducted. Samples were tested 10cm from the center of the crystal in no particular geographical order during the months of October and November 2014 in Sinking Spring, Pennsylvania. Further, this location received no detected radiological anomalies during the times of testing as evidenced by the continual air monitoring represented in Figure 3 below. As can be seen, average background at this location is 35 counts per minute (cpm) on an Inspector Geiger counter and remained steady throughout the testing period.

Figure 3. Historical graph for the period 10/13/2014 – 11/25/2014 at testing location in Sinking Spring, PA depicting the average air background of 35cpm.

All spectra were analyzed with a specific protocol: the measurement of predetermined areas of interest as described below, the analysis of any significance of peaks including the quantification of both uranium and thorium series, calculation of U235 enrichment, potassium levels and identification of potential contaminants including quantification of any cesium activity. A visual inspection was then performed along with any investigation and subsequent measurement doing so may have necessitated; therefore, within the sample notes, other detections not shown on the maps may be implied and weren't otherwise measured in all samples. Equipment restraints, check sources available to accurately determine detector efficiency at additional levels than currently calibrated with, uncertainties, and the level of expertise of the analyst are just a few of the limiting factors in reporting methods; therefore, results are tabulated and expressed up to a noted level of comfort for each area of interest.


Regions of Interest:


Uranium and Actinium Series:


Uranium: Natural uranium contains 99.2745% U238 and 0.72% U235 and is present in common rocks and soils around .5-5 ppm by weight; hence, its presence is expected in all of these samples. Average activity level is around 40 Bq/kg in soil (UNSCEAR 2000). This may vary widely due to soil and rock type. It is through the detection of its daughters, in which ideally it should be in secular equilibrium with if in its natural state, in addition to the presence of any Pa234m from which a clue into its nature may sometimes be extrapolated; therefore, the following gamma-rays were measured and calculated to estimate the values presented, see Figure 4.


U238 - 63.3 keV

Ra226 – 186.0 keV – also used to calculate U235

Pb214 – 295.2 keV, 351.9 keV

Bi214 – 609.3 keV, 1765.5 keV

Pb210 – 46.5 keV

Pa234m – 1001.0 keV, 766 keV


Upper limits and detections in Bq/kg for U238 activity at 63 keV. Samples marked with a red asterisk (*) resulted in a detection at 1001.0 keV (Pa234m) in addition to exhibiting little or no activity at 609 and 1765 keV indicating a partial contribution of processed uranium. All showed disruption in the U235 ratio. See sample notes for further individual characteristics and detections.

     Figure 4

Actinium (sample notes): As mentioned above, uranium in its natural state consists of 0.72% U235. Anything below this amount is technically considered depleted; however, as can be seen in results of tests, this region is subject to much interference. For all samples, at least some portion of contribution is expected to be from natural ore so in addition to checking for presence of Pa234m and lack of Bi214 for an indicator of a processed uranium contribution, the ratio of U235/U238 is also considered.

Areas of interest for the actinium series included the measurement of the following:


U235 – 143.8 keV, 163.4 keV; and, 186.0 keV (by separation of Ra226)

Rn219 – 401.8 keV


While the measurement and any resulting value or detection at 143.8 and 163.4 keV proved fruitful for confirmation purposes, ultimately it was the correction of the 186.0 keV line between the contribution from Ra226 and U235 that proved most legitimate in estimating a more logically fitting value to calculate the enrichment percentage for U235, and indeed, the more in equilibrium Ra226 was with U238 the more this was so as literature and studies say. From the specific activity of U238 and U235 as cited by Nucleide - Lara, where all nuclear data was obtained for this study (with the exception of Pa234m, instead using the Gilmore 2003 empirical intensity of 1.021%), the counts in the 185 keV peak can be mathematically apportioned between Ra226 and U235 by the following formula (*There is also another small correction for Th230 that can be made to the 186.0 keV peak; however, note that was not considered in this study.):

Corrected Ra226 = 0.5709 x apparent Ra226 at 186.0 keV

Estimated U235 = 0.02662 x apparent Ra226 at 186.0 keV (Gilmore 2011)

This U235 result was then used in combination with the U238 value from the 63 keV peak to determine the U234 content using the following formula as described in and derived from Calculation of Uranium Isotopic Activity Composition Based on Data from Various Assay Methods:

x / 0.29 = 27.18 + 0.3004 (U238/U235) + 0.00143 (U238/U235^2)


After obtaining the estimated calculation for U234, RadProCalculator was used to complete the remainder of the calculation for the quoted U235 percent enrichment. Keep in mind, while uncertainty is not calculated for the enrichment values, the lower the concentration of uranium, the worse the uncertainty. While exact values cannot be obtained, general conclusions can be reached that can be valuable in detecting biases.


In addition to the above, another ratio is cited in the sample notes included in this study. This value is derived from the raw counts in the 100 and 186 keV lines as documented as described by RadiationFinder. This simplistic test proved to serve as a valuable tool in confirming validity of the U235 enrichment calculation result.


Thorium Series: According to the UNSCEAR 2000 report, the average activity of Th232 in soil is 40 Bq/kg. The thorium decay chain is complicated and has slow in-growth of daughters if separated which makes estimating difficult.


The following areas of interest were measured to determine Th232 activity and potential contaminants (Figure 5):


Ac228 – 911 keV

Ac228 – 969 keV

Bi212 – 609.3, 1765.5 keV

Pb212 – 238.6 keV

Tl208 – 277, 583, 860 keV
U233 (Bi213) – 440 keV
U233 (Tl209) - 1567 keV

Results for thorium-232 are expressed as approximations in Bq/kg denoted by the approximation (~) if a detection were significant at 911 keV or 969 keV, denoted by (~<) if activity were present but without a significant detection, or by (nd) or “not detected” if there were no activity at 911 or 969. Similar amounts after the break in the chain caused by any potential separation were checked against. Sample sites are further marked on the map to indicate potential presence of U232, a contaminant created during the production of U233 by neutron bombardment of Th232. U232 falls along the same decay chain as Th232 with the exception that it skips Ac228 before entering; therefore, an abundance of activity for Bi212 and lack of presence of Ac228 is an indicator of such. Points marked on the map then are those samples that had detections at 1765 keV and negative values at both 911 and 969 keV. Samples marked with a blue (*) are those that resulted in significant detections of potentially U233 through its daughters at 440 keV (Bi213) and 1567 keV (Tl209).


All loose estimations should be received as such; however, the general information can be gleaned that most sites fall within expected ranges of normal Th232 content with approximately 5 showing abnormalities. Four samples: SRWA1.1, SRFL6.1, SRVT1.1 and SRNY3.1 showed indications of both U233 and U232; and SRKS1.1, while showing some activity at 1567, did not around 440 keV, so was marked for U232 only. See sample notes for further detections on individual samples.

     Figure 5

Potassium-40


According to the 1982 UNSCEAR report, the normal range for potassium K-40 in soils is 100-700 Bq/kg. While a check source for potassium-40 was not used in this study, numerous measurements have been made with samples of known average quantities of potassium-40 to within 20% uncertainty based on the calibration curve; therefore, the 1461 keV peak was measured and reported in upper limits and detections in Bq/kg under that assumption. See Figure 6.

     Figure 6

Neptunium Series, Cesium and Other Potential Contaminants:

     Figure 7

*Am241 (Americium-241) – 59.5 keV

*Np237 (Neptunium-237) - 86.5 keV

*Pa233 (Protactinium-233) – 312 keV - After 6 months, build up of Pa233 should be in equilibrium with Np237 so the presence of a detection at 312 keV acts as a verifying factor. While none of the samples in the study were sealed long enough to reach buildup, it was still measured (and detected in some) for the purpose to help differentiate which samples to test again later for verification. Samples marked then with a purple asterisk are ones with one or more detections at 59, 86 or 312 keV.


Cs137 (Cesium-137) – 662 keV – results were derived with the use of a calibrated NIST standard check source and expressed in Bq/kg with 95% confidence. While not shown on the map, an uncertainty budget is maintained by this lab, is currently at least 6.1% and is expressed in the sample notes.


Cs134 (Cesium-134) – 563, 569, 605, 796, 802 and 1354 keV – all energy levels were measured however due to half-life, intensity and time elapsed since the last known release of Cs134, values reported are an average of statistically significant detections, when obtained, at 605 and 795 keV in Bq/kg. It should be kept in mind that Cs134 has a complex decay scheme, is subject to true coincidence summing as discussed below with cobalt, and was not compared to a check source but rather relied on a calibration curve in this study. It is interesting to note the resulting ratios between Cs137 and Cs134 however in both quantity and number of detections.


The 2012-2013 soil study consisted of 48 samples, 22 Cs137 detections, 6 of which (or 12.5%) had Cs137 activity ranging from 4.9 – 19.1 Bq/kg with Cs134 activity ranging from 3.4 – 5.8 Bq/kg. The Cs134/137 ratio ranged from 0.27-0.84 with an average of 0.49 and a median of 0.52. This 2014 study consists of 60 samples, 30 Cs137 detections, 10 of which (or 16.7%) had Cs137 activity ranging from 5.7 – 10.2 Bq/kg with Cs134 activity ranging from 1.2 – 3.4 Bq/kg. The Cs134/137 ratio ranged from from 0.21-0.46 with an average of 0.34 and a median of 0.3.


Too many avenues of uncertainty exist which may affect those results to state with any confidence what caused the increase in number of detections of Cs134; however, a few possibilities include: more precise discrimination in peak measurement and analysis, more prominence in the spectra due to shorter-lived radionuclides having time to decay, recent production and deposition of Cs134 or maybe random coincidence. It is worthy to note however, the Cs134/Cs137 ratio is within the range consistent with the 2.3 year half-life of Cs134.


**Co60 (Cobalt-60) – 1173, 1332 keV – Cobalt-60 measurements are marked two ways on the map. Dark blue signifies that detections were made at both 1173 keV and 1332 keV with peak widths indicating the source is from a gamma-ray. Light blue asterisk denotes one or more of those detections being a result from a sum peak from potentially something or some process other than what is labeled as Cobalt-60. It is differentiated as, while not NIST standard, a check source of Co-60 was used to calibrate the detector for these tests, in addition to having known measurement data with which to compare shape and widths, is known to be subject to true coincidence summing (TCS) in addition to random summing – defined as two gamma-rays and/or x-rays emitting at the same time. Several factors can exacerbate the problem including proximity of the detector to sample, and in the case of cobalt-60, whether yttrium-88 is possibly present. The use of a large detector may as well, and while steps were taken to avoid as many avenues as possible, TCS is not dependent upon count rate. (Gilmore 2011). It is for those reasons then, in addition to samples being comprised of the environmental nature lending towards a higher possibility of Y88 which prompted the delineation; thus, for every sum peak detected at 1173keV, activity at 662 keV or any presence of Am241 or Cs137 were reviewed; and at 1332, those spectra were checked for the potential presence of Y88.


There are 2 samples that have sum peaks at 1332 keV: SRNV1.1 and SRTX2.1. Checking for possible summing from a single escape peak from Y88 at 1836.1 yielded SRNV1.1 showing a small but visible peak at 898 keV and produced a statistically significant detection at 1836 keV. SRTX2.1 also had a small visible peak at 898 but none at 1836 keV.


There were 5 samples that had sum peaks at 1173 keV: SRAZ2.1, SRIA5.1, SRAL1.1, SRMS2.1 and SRKY1.1. All lacked had either activity or detections at 59, 85, 312 or 722 keV and little or insignificant activity at 662 keV.


SRKY2.1 was unique in that it showed a sum peak at 1173 keV and a very thin peak at 1332 keV. There are small indications in the spectrum of Am241 for a possible 1173 explanation and interestingly, a statistically significant detection at 898 keV with a not significant, but visible peak at 1836 keV.


The above being evidence of summing at either of the energy levels for any of the samples is unclear; however, it is clear that unless summing, peak width and shape is taken into account, false attributions to detections can be a problem.


*Ru106 (Ruthenium106/Rhodium106)– 622 keV – Ru106 has a short half-life and is a beta emitter; however, its measurement through the detection of the gamma-ray emitting daughter Rh106 is possible and was still made for experimental purposes. While approximately 4 half-lives have past since the triple meltdowns at Fukushima Diachii Nuclear Power Plant in Japan, the last known source of release, the time passed prior to testing can be an advantage in that shorter lived radionuclides released have had a chance to decay, that if tested earlier may have contributed too much towards background to result in any statistically significant detections. On the other hand, releases are ongoing with the expectation that highly mobile Ru106 is still being produced at the site; therefore, it was also measured as a potential marker for recent criticalities. Intensity of the gamma-ray is low with only one gamma-ray to measure so uncertainty on any presence cannot be understated.


*Mn54 (Manganese-54) – 835 keV – Manganese-54 has a short half-life as does Ru106 and was measured for the same reasons; however, it has a high intensity at 835 keV with little to interfere at that level. While detections indicated are certain, due to only one gamma-ray to measure and lack of calibrating check source, uncertainty in any resulting activity being attributable to Mn54 should be considered with caution as well when interpreting results.


*I129 – 29 keV – Large sodium crystal detectors as used in this study are not the best to be using in this energy range for the purposes of quantifying activity due to the large number of x-rays in this region; however, detection may be possible so it was measured. Uncertainty lies not in detection at this level but in source, similarly to the Mn54 and Ru106 designations; however, statistically significant detections at this level, independent of any potential interference from cesium-137 at 32 keV, are noted before designating any detection on or about 29 keV as an I129 on the map. Note though, if the orange asterisk accompanies a purple one indicating the presence of Am241, Am241 is favored, meaning it is probable at least a portion of the contribution to the peak belongs to Am241.


Sample Notes by Region:

N. Pacific



Date collected

Date tested

Description

SRWA1.1

Kennewick, WA

10/30/14

11/22/14

10 miles south of Hanford, bare ground but untreated, top 1”



~<65 Bq/kg Th232 if any, U238 <95.2 Bq/kg in partial equilibrium with Ra226, 2.5% U235, 100/185 at 2.6, both Am241/Np237 and U233/U232 are indicated, detection at 1173 with activity at 1332, 240.8, 609.6, 186.0, 1566.7, 441.1, 723.1, Cs137 <5.9 Bq/kg

SROR1.2

Blue Mtns, OR

5/18/14

10/15/14

Same location, same site as SROR1.1 (4/1/12, tested 12/13/13, Cs137 19.1 Bq/kg +/- ½ (6.1%), Cs134 5.1 Bq/kg), Side of hill under trees, top 1”.



~65 Bq/kg Th232, U238 <86.8 Bq/kg in partial equilibrium, 0.5% U235, 100/185 ratio 1.9, Am241/Np237, Mn54, K40; 661.6, 1460.7, 400.7, 969.2, 835.2, Cs137 6.5 Bq/kg +/- 0.4 (6.1%)

SROR2.2

Gresham, OR

5/18/14

10/16/14

Same location, site within feet of SROR2.1 (4/1/12 tested 12/24/13 (Cs137 9.2 Bq/kg +/- 0.6 (6/1%), Cs134 4.9 Bq/kg), top 1”, grasses removed near Sandy River



~<75 Bq/kg Th232, U238 <119.9 Bq/kg in partial equilibrium with Ra226, 0.5% U235 with 100/185 ratio of 1.7, indications of transuranics, much activity at 1001 and 766 keV, Ru106/Rh106; Detections: 277.5, 1764.5, 621.4, 766.3, 352.5, 163.1, 661.9, Cs137 20.3 Bq/kg +/- 1.2 (6.1%), Cs134 not detected.


S. Pacific







Date collected

Date tested


SRNV1.1

Cherry Creek, NV

4/30/14

10/31/14

Top 1” in sage, removed, 100' from the road.



~45 Th232, U238 233.6 Bq/kg in partial equilibrium with Ra226, 0.94% U235, 100/185 ratio of 1.9, Am241 indications, K40, I129, sum peak at 1332: Detections: 228.1, 622.4, 660.4, 1460.7, 401.8, 164.0, 143.2, 46.9, 63.0, 29.4, 1332.5, 911.0, 605.0, 1836.5, 797.0, 1001.3, Cs137 6.5 Bq/kg +/- 0.4 (6.1%), Cs134 ~2.7 Bq/kg

N. Rockies



Date collected

Date tested


SRID2.1

Meridian, ID

5/1/14

10/27/14

20+ year untreated farmland, previously housed cattle, side of ditch bank under 1” weeds, set aside.



No Th232, U238 <87.6 Bq/kg in partial equilibrium with Ra226, 0.5% U235, 100/185 ratio 1.6, Am241/Np237, much activity at 766/722, K40; Detections: 1461.24, 131.11, 662.7,59.1, 87.2, Cs137 5.7 Bq/kg +/- 0.4 (6.1%), Cs134 2.8 Bq/kg

SRID3.1

McCammon, ID

5/24/14

10/28/14

Grass/weed pasture, top 1” after removal.



~<50 Bq/kg Th232, U238 136.7 Bq/kg, partial equilibrium with Ra226, 1.1% U235, 100/195 ratio of 1.9, possible Mn54, Am241/Np237, K40; Detections: 662.4, 237.2, 65.2, 46.9, 835.2, 401.9, 1461.2, 605.9, 795.6, Cs137 6.3 Bq/kg +/- 0.4 (6.1%), Cs134 ~2.7 Bq/kg

SRWY2.1

Granger, WY

5/25/14

10/29/14

Top 1”, no weeds or plant matter.



~<20 Bq/kg Th232, U238 <143.1 Bq/kg in partial equilibrium with Ra226, Ru106/Rh106, Np237 indications, K40; Detections: 622.4, 661.7, 401.9, 1461.2, 1764.39, 186.0, Cs137 4.3 Bq/kg +/- 0.3 (6.1%)

SRWY3.1

Rawlilns, WY

5/26/14

10/26/14

Top 1”, sage nearby and set aside.



~<30 Th232, U238 <135.6 Bq/kg in partial equilibrium, 0.7% U235, 100/185 ratio 1.5, Np237 indication, K40; Detections: 795.6, 605, 569.3, 562.9, 660.7, 1460.1, 1765.4, 609.6, 295.6, 860.4, 441.2, Cs137 6.1 Bq/kg +/- 0.4 (6.1%), Cs134 2.8 Bq/kg +/- 0.6 (20%)

SRWY1.2

Laramie, WY

5/26/14

11/22/14

Same location and site as SRWY1.1 (4/11/12, tested 12/29/13, Cs137 <35.1 Bq/kg) Bank of river, 5' above water.



~<45 Bq/kg Th232, U238 <103.4 Bq/kg in partial equilibrium with Ra226, Ru106/Rh106, Np237 indications, K40; Detections: 622.4, 661.7, 401.9, 1461.2, 1764.39, 186.0, Cs137 <7.4 Bq/kg

SRWY4.1

Cheyenne, WY

5/26/14

10/30/14

Top 1” in prairie grass, set aside.



No Th232, possible U232 and U233 indication, U238 <68.8 Bq/kg in partial equilibrium with Ra226, 0.7% U235, 100/185 ratio 1.6, Np237, detection at 1174 while none at 1332, K40; Detections: 228.1, 1461.2, 143.6, 622.4 312.9, 30.1, 1174.3, 1567.5, Cs137 < 6.3 Bq/kg

S. Rockies



Date collected

Date tested


SRNM1.1

Black River Village, NM

4/24/14

10/28/14

Top 1” desert scrub. Sample was clean of debris.



~<35 Bq/kg Th232 if any, U238 <68.3 Bq/kg, partial equilibrium, 2.4% U235 with 100/185 ratio at 1.9, Am241/Np237 detection, other Pu indications, very large 511 peak, accompanying 1022 peak, Ru106/Rh106, I129, K40; Detections: 277.5, 620.5, 569.3, 564.7, 660.1, 312.2, 1836.5, 1461.5, 163.5, 46.0, 30.1, Cs137 5.6 Bq/kg +/- 0.3 (1.6%)

SRNM2.1

Roswell, NM

4/25/14

10/21/14

Top 1” desert scrub, 20' from any structure.



~<35 Bq/kg Th232, U238 <100.7 Bq/kg, partial equilibrium with Ra226, 0.8% U235 with 100/185 ratio of 1.7, Am241/Np237, I129, K40; Detections: 86.3, 163.1, 1463.2, 132.0, 661.1, 563.8, 569.3, 30.1, Cs137 11.2 +/- 0.68 (6.1%)

SRNM3.1

Santa Fe, NM

4/26/14

11/14/14

Top 1” under scrub oak trees. Sample free of debris.



~30 Bq/kg Th232, U238 <61.0 Bq/kg, partial equilibrium, 0.76% U235 with 100/185 ratio of 1.9, appears extra contribution from something around 100 keV as other transuranics indicated, visual inspection resulted in Nb92 detection and indication of Nb94. Both are derived from enrichment plants and meltdowns; however due to low mobility, indicates a close source, K40, Rh106/Ru106; Detections: 871.1, 935.2, 621.4, 561.1, 791.2, 659.6, 1461.2, 1765.5, 352.5, 860.4, 583.8, 238.1, 970.8, 295.8, 1566.7, Cs137 4.1 Bq/kg +/- 0.3 (6.1%)

SRAZ2.1

Holbrook, AZ

4/28/14

10/20/14

Top 1” 400' from the road, no vegetation.



~<45 Bq/kg Th232, U238 <55.6 in partial equilibrium with Ra226, 0.77% U235, 100/185 ratio 1.5, K40, sum peak at 1174; Detections: 1174.6, 1461.2, 609.7, 143.9, 295.9, 1567.8, Cs137 <3.9 Bq/kg

SRAZ3.1

Page, AZ

4/28/14

10/28/14

Top 1”, 50' from the road, sage nearby.



No Th232, U238 <50.0, partial equilibrium, 0.75% U235 with 100/185 ratio of 1.5, Np237, possible lead contamination, detection at 1173 (8.0 Bq/kg), 1332 (<8.3), K40, I129; Detections: 659.6, 131.1, 1459.0, 164.0, 30.8, 46.9, 86.3, 238.2, 1565.6, 1173.5, Cs137 3.6 Bq/kg +/- 0.2 (6.1%)

SRUT1.1

Kanab, UT

4/29/14

11/1/14

Inside of a hill, 20' off a road.



No Th232, U232 indicators, U238 <68.0 in partial equilibrium with Ra226, 0.84% U235, 100/185 ratio 1.6, probably high ratios due to Pa234m contribution, K40, I129; Detections: 1460.1, 1001.0, 29.4, Cs137 <4.9 Bq/kg

SRUT2.1

Milford, UT

4/29/14

10/16/14

Top 1” desert sand, sage nearby. 6000' elevation.



~<55 Bq/kg Th232, U232, U238 <76.0 Bq/g, partial equilibrium, 0.88% U235, 100/185 ratio 1.6, Am241 indicators, much 1001 keV activity; Detections: 662.7, 583.9, 722.3, 277.5, 143.9, Cs137 6.8 Bq/kg +/- 0.4 (6.1%)

SRUT3.1

Laketown, UT

5/25/14

10/18/14

Top 1”, 30' from road under fence near sage.



~<40 Bq/kg Th232 if any, U232 indication in addition to detection at 277 and 766, U238 <123.25 Bq/kg in partial equilibrium with Ra226, 0.88% U235, 100/185 ratio at 1.7, Np237, K40, I129; Detections: 85.4, 240.0, 277.5, 312.2, 402.8, 1459.6, 660.7, 605.0, 494.0, 28.7, 1761.6, 47.9, 765.9, Cs137 7.6 Bq/kg +/- 0.5 (6.1%)

NW Central



Date collected

Date tested


SRKS1.1

Elwood, KS

5/30/14

10/29/14

Top 1” of soil under 5” of matted leaves



No Th232 but U232, U238 <153.6 Bq/kg with partial equilibrium with Ra226, large upper limit of U238 lending to 0.1% U235 calculation but with a 100/185 ratio of 1.6. K40, possible Mn54, I129; Detections: 661.7, 1460.1, 401.9, 608, 277.5, 1620.5, 835.2, 721.4, 29.7, Cs137 <8.1 Bq/kg

SRNE5.1

Kearney, NE

5/27/14

11/3/14

Top 1”, down slope of a small lake, under trees



~<20 Bq/kg Th232 if, U238 <60.1 Bq/kg with partial equilibrium with Ra226, 1.5% U235 with 100/185 ratio at 1.6, Nat. U, Np237, Ru106, K40; Detections: 621.4, 660.1, 295.8, 312.2, 1461.2, Cs137 3.6 Bq/kg +/- 0.2 (1.6%)

SRIA4.1

Council Bluffs, IA

5/30/14

10/16/14

Top 1” near fence under 4” dead grass set aside. Within 5 miles of SRIA1.1 2012.



~35.0 Bq/kgTh232, poss U232 contribution, U238 <115.6 Bq/kg in partial equilibrium with Ra226, 0.53% U235 with 100/185 ratio of 1.4, 132.0, 1760.3, 910.3, 611.0, Cs137 <14.9 Bq/kg

SRIA5.1

Percival, IA

5/30/14

10/15/14

Top 1”, 20' off a road, removed 4” plant matter.



No Th232, U238 <104.5 Bq/kg in partial equilibrium with Ra226, 0.58% U235 and 100/185 ratio of 1.6, 1001 detection, Am241, sum peak at 1173.4, K40; Detections: 1460.7, 163.7, 1001.0, 312.2, 1173.4(sum), Cs137 <15.1 Bq/kg

SRMO1.1

La Monte, MO

5/30/14

10/17/14

100' off a road in thick grasses under 3” matter set aside.



No Th232, U238 <140.7 Bq/kg with partial equilibrium with Ra226, detections at 609 and 1764 suggest at least contribution from processed uranium giving rise to 0.1% U235; possible the 100/185 ratio of 1.9 arises from the detection at 722, 440, 402 and 163; Detections: 608.6, 1760.3, 162.1, 1460.1, 402.8, 722.0, 1566.7, Cs137 <9.9 Bq/kg

SRMO2.1

Montgomery, MO

5/31/14

10/17/14

Top 1” under 2” leaves set aside



~<40 Th232, U238 <176.8 Bq/kg, partial equilibrium with Ra226, 0.4% U235 with 100/185 ratio 1.7, 1001 detection, prominent 511 peak present; Detections: 186.9, 143.9, 1002.8, Cs137 <10.1 Bq/kg


SW Central



Date Collected

Date Tested


SRLA1.1

Chalmette, LA

4/15/14

10/24/14

Top 1” soil under 1” leaf matter set aside.



~<55 Bq/kg Th232, indication of partial contribution from U232, U238 <100.0 Bq/kg, partial equilibrium, 0.6% U235, 100/185 ratio 1.6, Np237/Am241 detections, peak at 1173 while almost none at 1332; K40; Detections: 795.3, 569.3, 660.78, 1461.24, 311.32, 87.2, 584.5, 1173.2, 1619.4, Cs137 7.3 Bq/kg +/- 0.4 (6.1%), Cs134 2.3 Bq/kg

SRLA2.1

Avery Island, LA

4/17/14

10/24/14

Top 1” under 3” leaves, removed.



~<50 Bq/kg Th232, U238 <104.8 Bq/kg, partial equilibrium, 1.1% U235, 100/185 ratio 1.8, indications of Am241/Np237, K40; Detections: 569, 563.8, 660.5, 609.6, 1461.2, Cs137 10.2 Bq/kg +/- 0.6 (6.1%), Cs134 2.5 Bq/kg

SRTX1.1

Galveston, TX

4/19/14

11/3/14

Sand from grassy dune 100 yards from water.



~40 Bq/kgTh232, U238 56.7 Bq/kg, partial equilibrium with Ra226, 6.5% U235, 100/185 ratio 1.6, much 1001 activity, transuranic indicators – complicated uranium scheme and especially odd/high for sand; Detections: 186.0, 969.2, 238.1, 1620.5, 64.3, 660.1, Cs137 3.6 Bq/kg +/- 0.2 (6.1%)

SRTX2.1

Dale, TX

4/22/14

11/4/14

Both SRTX2.1 and SRTX3.1 are from the same 10 acre lot. 2.1 comes from recently turned top soil (<4 years), previously sitting about 4-6” below the surface. Sporadic grasses were on top of area.



~<25 Bq/kg Th232, U238 <71.6 Bq/kg, partial equilibrium with Ra226, 0.5% U235 and 100/185 ratio of 1.4, detection at 1001; Detections: 46.5, 1001.0, 1333.8 (sum), Note: Same location as SRTX3.1, sample from recently turned soil 12” down, Cs137 <6.2 Bq/kg

SRTX3.1

Dale, TX

4/22/14

10/23/14

Same location as SRTX2.1; however taken from the back of the property, top 1”, no grasses, leaves or plant matter.



~20 Bq/kg Th232, no U232 indication, U238 79.3 Bq/kg, partial equilibrium, 2.0% U235 with 100/185 ratio at 1.6, K40 – sample from same location as SRTX2.1 but from long-term undisturbed surface without grasses or leaves; Detections: 912.1, 238.1, 64.3, 186.9, 295.8, 143.0, 163.1, 401.9, 1459.0, 131.1, 660.8, 567.4, 794.5, 800.3, 605.0, 562.9, Cs137 5.7 Bq/kg +/- 0.4 (6.1%), Cs124 1.2 Bq/kg

SRTX4.1

Fort Stockton, TX

4/23/14

11/22/14

Top 1”, small amount desert brush nearby.



~50 Bq/kgTh232, U238 <85.1 Bq/kg, partial equilibrium, 0.7% U235 with 100/185 ratio of 1.7, K40, Detections: 969.5, 583.9, 795.6, 605.0, 145.7, 1463.44, 661.7, 1566.0, Cs137 6.1 Bq/kg +/- 0.4 (6.1%), Cs134 1.7 Bq/kg


NE Central



Date Collected

Date Tested


SRIN3.1

Richmond, IN

6/2/14

10/18/14

350' off road under trees and 4” leaf matter removed



No Th232, U238 <135.1 Bq/kg in partial equilibrium with Ra226, 0.4% U235 with 100/185 ratio of 1.3, K40, Ru106, I129; Detections: 622.5, 1461.2, 186.0, 30.1, Cs-137 <5.9 Bq/kg

SRIL4.1

Vandalia, IL

6/1/14

10/17/14

Top 1” under trees, 2” leaves, set aside.



~<65 Bq Th232 (1621 is sum peak), U238 <100.5 Bq/kg in partial equilibrium with Ra226, 1.0% U235 and a 100/186 ratio of 1.6, natural uranium, K40, Np237, Ru106; Detections: 312.4, 1616.8, 312.4, 46.0, 1461.2, 621.4, Cs137 <10.3 Bq/kg

SRIL5.1

Marshall, IL

6/2/14

10/22/14

Top 1”, under trees, removed 3” needles.



~<40 Bq/kgTh232, No U232, U238 <109.7 in partial equilibrium with Ra226, 1.1% U235 with 100/186 ratio at 1.6, natural uranium, K40; Detections: 1462.7, 402.8, 164.0, 609.6, 239.1, Cs137 <2.3 Bq/kg

SROH3.1

Zanesville, OH

6/4/14

10/21/14

Top 1”, 50' from a road near trees, no leaves



~45 Bq/kg Th232, No U232, U238 105.9 Bq/kg in partial equilibrium with Ra226, 0.6% U235 with 100/185 ratio at 1.8, no Pa234m activity at 1001 or 766, natural uranium; K40, Ru106; Detections: 661.2, 1463.8, 46.5, 62.5, 583.0, 911.0, 621.4, 1764.4, Cs137 7.9 Bq/kg +- 0.5 (6.1%)

SROH4.1

Belmont, OH

6/5/14

10/23/14

Top 1”, in bushes, under leaves, removed.



~35 Bq/kg Th232 with possible U232 contribution, U238 <171.2 Bq/kg in partial equilibrium with Ra226, 0.76% U235 with 1.8 100/185 ratio natural uranium, K40; Detections: 660.3, 401.9, 164.0, 145.7, 1762.8, 859.3, 911.0, 1462.3 Cs137 <14.5 Bq/kg


SE Central



Date collected

Date tested


SRMS1.1

Biloxi, MS

4/8/14

10/31/14

Sand, backside of dunes amongst grasses



~<45 Bq/kg Th232, U238 <79.8 Bq/kg, partial equilibrium with Ra226, 0.5% U235 with 100/185 ratio of 1.7, even less leads and bismuths, much activity but lacking detection at 1001, Note this is much uranium especially for a sand sample, K40, possible Ru106/Rh106; Detections: 1461.2, 860.4, 622.4, Cs137 <5.4 Bq/kg

SRMS2.1

Ocean Springs, MS

4/12/14

10/16/14

Top 1” under 2” leaves set aside



No Th232, <150.3 Bq/kg U238 with 0.5% U235 and accompanying 100/185 ratio of 1.3. partial equilibrium with Ra226, no leads with much activity at 1001, 1764 and 766. Possible Ru106/Rh106 and sum peak at 1773 which appears is not from any Cs137 content; Detections 622.4, 1175.5(sum), 584.5, Cs137 <10.23 Bq/kg

SRAL1.1

Glen Allen, AL

4/8/14

10/20/14

Top 1” under trees, few leaves, removed



No Th232, U238 <136.9 Bq/kg in partial equilibrium with Ra226, 0.7% U235 with 100/195 ratio of 1.6, sum peak at 1172, Am241/Np237 indications, I129; Detections: 1172.2, 30.1, 277.7, 314.0, 1761.5, Cs137 <5.7 Bq/kg

SRAL2.1

Fort Davis, AL

4/9/14

10/23/14

Top 1” under trees under 3” leaves set aside



No Th232, U238 <117.1 Bq/kg in partial equilibrium with Ra226, 1.1% U235 and 100/185 ratio of 1.8, activity where Am241/Np237 is found, K40; Detections: 659.9, 1462.3, 401.9, 164.5, 1765.5, 609.2, Cs137 5.7 Bq/kg +/- 0.4 (6.1%)

SRAL3.1

Black Rock, AL

4/10/14

10/25/14

Top 1”, edge of trees under leaves, set aside



~50 Bq/kg Th232, U238 <87.2 Bq/kg, partial equilibrium, 0.7% U235, 100/185 ratio 1.7, K40; Detections: 623.4, 795.9, 569.3, 563.8, 660.8, 401.9, 1459.78, 583.9, 969.2, Cs137 7.1 Bq/kg +/- 0.4 (6.1%)

SRTN5.1

Lawrenceburg, TN

4/7/14

10/25/14

Top 1” under trees, 5” plant matter, removed



~<80 Bq/kg Th232, U238 <103.3 Bq/kg with 0.6% U235 and 100/185 ratio of 1.4, partial equilibrium with Ra226, possible lead contamination, possible Ru106/Rh106, appears cesium-137 present but wide and not statistically significant above background, potentially due to detections: 802, 605, 795.9, 569.3, 662.5, 1462, 402.8, 46.9, 1565.6, 621.4, Cs137 <9.3 Bq/kg

SRTN6.1

Philadelphia, TN

10/21/14

11/20/14

Same location as SRTN2.1 (9/4/13, tested 12/20/13, Cs137 11.1 Bq/kg +/- 0.7 (6.1%), Cs134 5.8 Bq/kg), same west facing bank slope but ~50' down the bank, more tree coverage, bare ground.



~<55 Bq/kg Th232 if any, U238 <168.1 Bq/kg in partial equilibrium with Ra226, 0.6% U235 with a 100/185 ratio of 1.4; possible Np237/Am241, K40, I129; Detections: 860.4, 351.6, 46.9, 30.4, 1461.2, Cs137 <16.2 Bq/kg

SRKY1.1

Alton, KY

4/4/14

10/26/14

Top 1” under trees and 3” wet leaves set aside



~<70 Bq/kg Th232, U238 <159.0 Bq/kg, partial equilibrium with Ra226, 0.6% U235 with 100/185 ratio of 1.6, much activity at 1001, K40, detections where Mn54, Ru106 lie, Sum peak at 1174, significant peak at 1333 – related to sum peaks in SRKY2.1?, Am241/Np237 indications; Detections: 621.4, 569.3, 661.04, 1460.6, 163.1, 295.8, 835.2, 1174.6, 1332.9, Cs137 13.5 Bq/kg +/- 0.8 (6.1%)

SRKY2.1

Rowletts, KY

4/5/14

10/25/14

Top 1”, under trees, no plant matter



No Th232, U238 <117.7 Bq/kg in partial equilibrium with Ra226, 1.1% U235 with 100/185 ratio of 1.7, sum peaks at 1173 and 1332, K40; Detections: 1459.0, 163.1, 898.9, 1173.1, 1332.7, Cs137 <10.7 Bq/kg


New England



Date collected

Date tested


SRVT1.1

Brattleboro, VT

5/1/14

10/13/14

Top 1” in wooded area. No mention of vegetation. Sample was clean soil with little root matter removed when processing.



No Th232, possible U233/U232; U238 <216.8 Bq/kg, little in comparison to activity at 1001 and 766, ½ equilibrium with Ra226 so low ratio at .4 but low ratio also for 100/185 keV lines at 1.2, Co60, good at 1332/half at 1173. Nearby Mass shows similar in cobalt; detections at 59.4, 1565.6, 1620.4, 1173.5, 1332, Cs137 <15.0 Bq/kg

SRMA1.1

Greenfield, MA

5/1/14

10/12/14

Top 1” in wooded area. No mention of vegetation. Sample was clean soil with little root matter removed during sample intake.



No Th232, possible contribution from U232 activity at 1621; U238 92.2 Bq/kg, Co60(both 1173 and 1332 significant)/K40/possible I129; detections: 860.1, 63.4, 164.0, 1460.1, 1173.4, 1332.3, 28.7, Cs137 <9.8 Bq/kg

SRCT1.1

New London, CT

5/1/14

10/14/14

Top 1” in wooded area. No mention of vegetation. Sample was clean soil.



~40 Bq/kg Th232, no U232 indicators, U238 <82.6 Bq/kg, partial equilibrium with Ra226 while results in 0.7% U235, 100/185 ratio is 1.3, makes sense as despite 143.9 detection, it may be partially processed U due to 1001 and 766 activity and 131 detection; Detections: 661.7, 131.1, 143.9, 46.9, 911.6, 192.9, 1292.1, Cs137 7.2 Bq/kg +/- 0.4 (6.1%)

SRCT2.1

Bristol, CT

9/16/14

11/12/14

Top 1” under 2” leaf matter set aside.



~<70 Bq/kg Th232, U238 <82.4 Bq/kg, 0.7% U235 but with partial equilibrium with Ra226 and 1.5 100/185 ratio, lacks lead and bismuth, detections at 1001 and 766 indicate partial processed uranium, too early for any Np/Am indications; Detections: 661.7, 1001.0, 582.1, 277.5, 767.1, Cs137 6.1 Bq/kg +/- 0.4 (6.1%)

SRCT3.1

Kent, CT

10/4/14

11/11/14

Same location as SRCT4.1, top 1” under 3” leaves, about 10' off road.



~<35 Bq/kg Th232 no U232 indicators, U238 <90.1 Bq/kg, no Pa234m indicators, partial equilibrium with Ra226, 0.5% U235 ratio and 1.5 ratio between 100/185 keV lines, so mostly if not all natural U, possible Am241. Same location as SRCT4.1 but under several inches of leaves. Detections: 144.83, 59.8, 622.1, Cs137 <7.5 Bq/kg

SRCT4.1

Kent, CT

10/4/14

11/12/14

Same location as SRCT3.1, different site, top 1” under trees and 6” leaves, set aside.



No Th232, U238 <94.3 Bq/kg, partial equilibrium with Ra226 results in 0.1% U235 whereas 100/185 ratio is 1.5, possible other transuranics. Same location as SRCT3.1 but surface sample, not under leaves. Detections: 277.5, 661.7, 802.2, 795.6, Cs137 10.1 Bq/kg +/- 0.6 (6.1%), Cs134 ~3.7 Bq/kg



N. Atlantic



Date collected

Date tested


SRPA.1

Burnt Cabins, PA

6/5/14

10/22/14

Top 1” near stream under 2” leaves, set aside.



~<40 Bq/kgTh232, U238 <82.1 Bq/kg, partial equilibrium with Ra226 with 0.8% U235 and a 1.9 100/185 ratio, Rn219 detection at 402; K40; Detections: 661.7, 352.6, 609.4, 402.8, 295.8, 1462.1, 788.8, 722.0, 440.3, Cs137 <8.4 Bq/kg

SRPA7.1

Sinking Spring, PA

9/7/14

11/4/14

Long-term untreated garden soil, no plant matter.



~<40 Bq/kg Th232, No U232 indicators, U238 <133.1 Bq/kg, partial equilibrium, upper limits produce 0.1% U235 but 100/185 at 1.5 and presence of Rn219 more indicative of natural uranium as ratio suggests, K40; Detections: 1461.0, 401.9, Cs137 <7.8 Bq/kg

SRPA8.1

Forksville, PA

10/6/14

11/21/14

Same location as SRPA9.1, different site ~1 mile away, top 1” under 3” leaves, set aside.



~<80 Th232, U238 <239.1 Bq/kg partial equilibrium, upper limit producing erroneously high 1.9% U235 when despite 186keV detection, U235 is lacking. 100/185 shows more accurately with 1.2 ratio; possible Am241/Np237; Detections: 131.1, 1762.2, 609.6, 185.1, Cs137 <14.6 Bq/kg

SRPA9.1

Forksville, PA

10/6/14

11/29/14

Same location as SRPA8.1, different site ~1 mile away, top 1” under 2” leaves, set aside.



No Th232, U238 <175.6 Bq/kg partial equilibrium with Ra226, similar to SRPA8.1 with 1.6% U235 and 100/185 ratio of 1.6 indicative of mostly natural uranium; Detections: 351.6, 186.0, 1566.7, Cs137 <7.6 Bq/kg

SRWV2.1

Weston, WV

4/2/14

10/19/14

Top 1”, 6' above a creek under 2' plant matter



~<40 Bq/kg Th232, U238 98.4 Bq/kg in partial equilibrium with Ra226, 0.6% U235 and 100/185 ratio of 1.4 indicating natural uranium; Np237, K40, I129, Ru106/Rh106; Detections: 87.2, 239.1, 63.4, 610.5, 1765.1, 48.0, 165.3, 131.1, 401.7, 1461.2, 661.3, 620.8, 1383.8, 792.1, 605.8, Cs137 7.5 Bq/kg +/- 0.5 (6.1%), Cs134 2.1 Bq/kg

SRNJ1.1

Hammonton, NJ

3/22/14

10/14/14

Top 1” no plant matter, middle of untreated field.



~25 Bq/kg Th232, no U232 indicators, U238 <58.8,partial equilibrium with Ra226, some 1001/766 activity, despite .79% U235 from enrichment calculation and detection at 163, the 100/185 indicates low U235 at 1.3, is 163 partially from another transuranic and not U235?; K40, Np237, is then the detection at 29.3 potentially a contribution from I129 or U237?; Detections: 312.2, 29.3, 911.6, 238.1, 277.4, 350.7, 1763.7, 163.5, 1461.3, 661.7, Cs137 5.8 Bq/kg +/- 0.4 (6.1%)

SRNY1.1

Carmel, NY

5/1/14

10/15/14

Top 1”, grasses removed before sampling.



~<110 Bq/kg Th232, no U232 indication, U238 <168.7, partial equilibrium resulting in .4% U235 and 100/185 ratio at 1.3, heavy activity at 1001 and 766, K40, Np237 indication; Detections: 1460.7, 861.0, 87.2, Cs137 <19.3 Bq/kg

SRNY2.1

Catskill Mtns.

9/18/14

11/13/14

Off road, side of hill between rocks



~<25 Bq/kg Th232, U238 <61.9 Bq/kg, partial equil0.8% U235 with 1.5 100/185 indicating natural uranium, possible Am241/Np237 but too early for buildup, possible I129; Detections: 352.5, 30.8, 1567.8, 1764.7, Cs137 <3.8 Bq/kg

SRNY3.1

Norwich, NY

9/18/14

11/11/14

No collector description. Sample was clean dark soil and free from debris.



~<55 Bq/kg Th232, U233/U232 indication, U238 <88.6, partial equilibrium with Ra226, interference around 186 for a 0.1% U235 ratio but 1.5 ratio for 100/185, detection at 143 likely mostly natural uranium, detections at both 440 and 1567 for U233, possible alpha; Detections: 661.7, 143.9, 1333.5, 441.2, 1566.3, Cs137 <6.6 Bq/kg


S. Atlantic



Date collected

Date Tested


SRFL6.1

Ellenton, FL

10/20/14

11/23/14

No collector description. Sample was clean and free from debris.



~<50 Bq/kg Th232, contribution from U232 strongly indicated, U233 indicated, U238 <153.3 Bq/kg in partial equilibrium with Ra226, 0.72% U235 and 100/185 ratio of 1.5, Np237; Detections: 661.7, 609.6, 604.5, 795.6, 312.2, 583.9, 1620.5, 1567.8, 440.3, Cs137 9.3 Bq/kg +/- 0.6 (6.1%), Cs134 ~3.4 Bq/kg


References:


Calculation of Uranium Isotopic Activity Composition Based on Data from Various Assay Methods, http://www.lanl.gov/BAER-Conference/BAERCon-43p016.pdf


Discrimination of Radionuclides in High-Resolution Spectral Gamma Logging, Henwood, P.D., McCain, R.G., WM'06 Conference, 2006. http://www.wmsym.org/archives/2006/pdfs/6267.pdf


Laboratoire National Henri Becquerel, http://www.nucleide.org


An Objective Look at Uranium, http://radiationfinder.com/DU


Practical Gamma-Ray Spectrometry, 2nd Ed., Gordon R. Gilmore, 2011.


Radprocalculator.com


Results of Radioactive Analysis Around Fukushima Diachii Nuclear Power Station, http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/index-e.html


UNSCEAR, (United Nations Scientific Committee on the Effects of Atomic Radiation), Report to the General Assembly United Nations, New York, 2000. (UNSCEAR, 1982)


UNSCEAR, (United Nations Scientific Committee on the Effects of Atomic Radiation), Report to the General Assembly United Nations, New York, 2000. (UNSCEAR, 2000)

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