Fourth Quarter 2006
INL Quarterly Site Environmental Report
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Quality Assurance

The ESER Quality Assurance Program consists of five ongoing tasks which measure:

  1. data completeness
  2. data accuracy, using spike, performance evaluation and laboratory control samples
  3. data precision, using split samples, duplicate samples and recounts
  4. presence of contamination in samples, using blanks.

The following discussion briefly summarizes the results of the quality assurance program for the period from October 1 to December 31, 2006.

Method Uncertainty

The Quality Assurance Project Plan (QAPP) establishes data quality and method quality objectives for the ESER surveillance program (Stoller 2007).  Since the primary concern is with detection, the lower bound for the method uncertainty is set at zero.  The upper bound is defined by the ESER program as the maximum concentration for the range of data over the past ten years, excepting those values determined to be extremes using box plots generated by a statistical data program.  Each individual result is checked for acceptance on the basis of the result, whether it is below the lower limit (i.e., a negative value), greater than the upper limit, or between the lower and upper limit (the most common occurrence).  The calculated method uncertainty is then compared to the 1s measured uncertainty.  A sample is deemed acceptable when the measured 1s uncertainty is less than the calculated uncertainty.  The upper bound values were recently re-evaluated and revised.  Preliminary results indicate that more calculated method uncertainties for detected results were acceptable.  In the fourth quarter of 2006, approximately 97.2 percent of method uncertainties were in the acceptable categories.

Data Completeness

The Quality Assurance Project Plan specifies a 98 percent completeness goal for all regularly scheduled sample types.  This goal does not include variable sample types such as game animals and precipitation, where the ability to produce a sample is not controllable. Data completeness for sample collection and delivery was 100 percent during the fourth quarter for all samples types with the following exceptions.

One paper air filter from Craters of the Moon during the week of November 8 was found to missing from the filter head upon return to the office.  The completeness of the air filter data set is therefore 99.6 percent for the fourth quarter. 

The following results were lost in analysis during the fourth quarter:  one Pu-238 result in air, one Pu-239/240 result in air, 1 Am-241 result in waterfowl and three Pu-239/240 results in waterfowl.

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Data Accuracy

Spike Samples Submitted with Field Samples

The ESER obtains spike samples from the Department of Energy’s Radiological and Environmental Sciences Laboratory, which prepares the spikes and issues data reports with the results. Some spikes are also obtained from private vendors, such as Analytics and Environmental Resource Associates, who provide a certificate of analysis with the sample. During the fourth quarter of 2006, data were obtained for the following spikes:

Table 5.  Results for Milk Spike-Sample ID 06-MI-0114

Constituent

ERA Activity

(pCi/L ± 1σ )

EAL Activity (pCi/L ± 1σ)

Percent Deviation

Agreement?

Iodine-131

10.0 ± 1.7

7.12 ± 1.87

-28.8

No

Note:  Subsequent recounts indicated activities of 10.1 (+1.0%) and 9.62 (-3.8%) pCi/L.

Note:  Activities are as of 10/3/06.

 

Performance Evaluation Samples

The QAP program was discontinued following the March 2004 distribution. Performance evaluation samples are now prepared through the Mixed Analyte Performance Evaluation Program (MAPEP), administered by the Department of Energy’s Radiological and Environmental Sciences Laboratory. DOE has mandated that all laboratories performing analyses in support of the Office of Environmental Management shall participate in MAPEP. The program distributes samples of air, water, vegetation and soil for analysis in approximately January and June. Both radiological and nonradiological constituents are included in the program.

Both the Idaho State University EAL and Teledyne Brown Engineering participated in the MAPEP Study reported in November 2006. Results are tabulated below for those analyses performed by each laboratory. (A = Acceptable, W = Acceptable with warning, N = Not acceptable)
 

Table 6. MAPEP Results for November 2006

Idaho State University Environmental Assessment Laboratory

Matrix: Air (Bq)

Analyte

EAL Result

MAPEP Result

Bias (percent)

Acceptable Range

Evaluation

Cesium-134

2.9

3.147

-7.8

2.20-4.09

A

Cesium-137

1.8

1.805

-0.3

1.26-2.35

A

Cobalt-57

2.6

2.582

0.7

1.81-3.36

A

Cobalt-60

1.6

1.577

1.5

1.10-2.05

A

Manganese-54

2.0

1.92

4.2

1.34-2.5

A

Gross alpha

0.08

0.290

-72.4

0.0-0.580

A

Gross beta

0.34

0.359

-5.3

0.180-0.538

A

Matrix: Water (Bq/L)

Cesium-134

97.9

112.82

-13.2

78.97-146.66

A

Cesium-137

193.6

196.14

-1.3

137.30-254.98

A

Cobalt-57

209.3

213.08

-1.8

149.16-277.00

A

Cobalt-60

47.7

47.5

0.4

33.2-61.8

A

Tritium

401.4

428.85

-6.4

300.20-557.50

A

Gross alpha

0.45

1.033

-56.4

0.0-2.066

A

Gross beta

1.05

1.03

1.9

0.52-1.54

A

Matrix: Soil (Bq/kg)

Cesium-134

530.1

452.13

17.2

316.49-587.77

A

Cesium-137

687.5

525.73

30.8

368.01-683.45

N

Cobalt-57

845.6

676.33

25.0

473.43-879.23

W

Manganese-54

791.1

594.25

33.1

415.98-772.52

N

Potassium-40

955.9

604

58.3

423-785

N

Zinc-65

1214.9

903.61

34.5

632.53-1174.69

N

Matrix: Vegetation (Bq)

Cesium-134

7.06

7.487

-5.7

5.24-9.73

A

Cesium-137

5.71

5.495

3.9

3.85-7.14

A

Cobalt-60

5.82

5.806

0.2

4.06-7.55

A

Manganese-54

8.28

8.351

-0.9

5.85-10.86

A

Zinc-65

6.30

5.984

5.3

4.19-7.78

A

 

Teledyne Brown Engineering

Matrix: Air (Bq)

Analyte

TBE Result

MAPEP Result

Bias (%)

Acceptable Range

Evaluation

Americium-241

0.124

0.142

-12.7

0.10-0.18

A

Cesium-134

2.62

3.147

-16.7

2.20-4.09

A

Cesium-137

1.98

1.805

9.7

1.26-2.35

A

Cobalt-57

2.65

2.582

2.6

1.81-3.36

A

Cobalt-60

1.63

1.577

3.4

1.10-2.05

A

Manganese-54

2.10

1.92

9.4

1.34-2.50

A

Plutonium-238

.0123

0.118

4.2

0.08-0.15

A

Plutonium-239/240

8.22e-3

--a

 

 

A

Strontium-90

0.549

0.62

-11.5

0.43-0.81

A

Uranium-234/233

0.140

0.134

4.5

0.09-0.17

A

Uranium-238

0.136

0.139

-2.2

0.10-0.18

A

Zinc-65

-0.163

--a

 

 

A

Gross Alpha

0.134

0.290

-53.8

0.0-0.580

A

Gross Beta

0.358

0.359

-0.3

0.180-0.538

A

Matrix: Water (Bq/L)

Americium-241

2.09

2.31

-9.5

1.62-3.00

A

Cesium-134

99.8

112.82

-11.5

78.97-146.66

A

Cesium-137

191

196.14

-2.6

137.30-254.98

A

Cobalt-57

203

213.08

-4.7

149.16-277.00

A

Cobalt-60

46.2

47.5

-2.7

33.2-61.8

A

Tritium

471

428.85

9.8

300.20-557.50

A

Iron-55

173

165.4

4.6

115.8-215.0

A