slac radioanalysis laboratory

SLAC RadioanalysisLaboratoryHenry Brogonia

Dosimetry and Radiological Protection Group (DREP)

DOE Environmental Radiation Protection Program Review (July 23-24, 2007)

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Radioanalysis Laboratory Mission

“To provide high quality, accurate, and timely radiological analysis to SLAC

customers and to support SLAC mission and operations.”

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Radioanalysis Laboratory Services

– Measurements to support the radiological environmental protection program, e.g.,

• characterizing tritium and other radionuclides in environmental samples,

• providing radiological information for sanitary sewer discharges, facility clean-up and decommissioning

– Measurements of radionuclides in SLAC accelerator cooling systems

– Measurements of radionuclides in samples for the Field Operations Group

– Characterizing radioactive waste for the Radioactive Waste Group

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Main isotopes at SLAC

Radionuclide Material Method of Detection

H-3 (low energy beta) Water Liquid Scintillation Counting

Be-7 Water, Soil Gamma Spectroscopy

Na-22, Co-60, Mn-54, Co-57 Soil and Metals Gamma Spectroscopy

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Sample profile (1995-2007)Sample Type Number CustomerGround Water 1491 EPDStorm Water 301 EPDWaste Water 3155 CEFOther Water 948 RPD, CEFOther Liquid 1000 RPD, CEF

Oil 77 RPDResin 465 CEF

Air Sample 8 RPDSoil 526 RPD

Concrete 213 RPDSwipe 669 RPD

Miscellaneous 724 RPDTotal 9577 ----------

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Laboratory Layout

LSC Laboratory Area housing two LSC machines, sample storage cabinets and preparation area.

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Laboratory Layout

Gamma Spectroscopy Counting Room housing two HPGe systems with lead caves for low background counting

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Equipment Inventory

Instrument Name Instrument Type Software Radiation monitored

Packard Tri-Carb1900TR

Liquid Scintillation Counter Packard Tri Carb LiquidScintillation Analyzer

(MS-DOS)

H-3

Packard Tri-Carb 3100 Liquid Scintillation Counter Quantasmart Version 2.02 H-3

ORTEC GEMX HPGe (50%)

n-type, Low Background HPGe Gammavision Version 6.01 Gamma emittingnuclides

ORTEC GEM HPGe (40%)

p-type, Low Background HPGe Gammavision Version 6.01 Gamma emittingnuclides

ORTEC Transpec Portable HPGe Gammavision Version 6.01 Gamma emittingnuclides

BNC SAM Portable Sodium Iodide BNC Software Version 2.11.01

Gamma emittingnuclides

Hach Microdistillation Distillation equipment N/A N/A

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Sample Analysis

Sample requires LSC?

Sample requires Gamma Spec?

Perform LSC analysis for H-3

Perform Gamma Spectroscopy

Enter sample results into database

Release results to customer

Obtain approvals

Results make sense?

Review sample analysis and QA/QC

results

Reanalyze Sample?

Start:Receive sample and Sample Information Sheet. Sign Chain of

Custody

End:Dispose of

Sample

Yes

NoNo

Yes

Yes

Yes

No

No

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Customer SIS SLAC Environmental SAMPLE ID#: L14890 Date Taken:______________________________________________________

System/ Description _______________________________________ _____________________________________________________________ Taken By:________________________________________

Mail Stop ______Ext:_______________________________

_

To request analysis a Sample Information Sheet (SIS) is filled out and a sample label is attached to the container by the customer.

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COC Log

The chain of custody (COC) log is signed by the customer and the operator when the sample is relinquished to the Lab.

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Analysis DeterminationFor Liquid Scintillation:

– All liquids– H-3 swipes

For Gamma Spectroscopy:– Positive channel C result from LSC (this channel monitors for

any beta/gamma emitters other than H-3)– Any sample from waste water systems with historically positive

gamma results (i.e., LCW from BDE and HX collimator)– Groundwater wells with positive H-3 results– Radiological-guarding groundwater wells– Oil

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LSC Preparation and Counting• Samples are prepared in 20 ml plastic vials

– 5 ml sample– 15 ml cocktail (Ultima Gold)

• A Background and two Standard vials are counted with each batch

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LSC Analysis & Software

• Background subtraction• 3 counting windows

– Channel A, 0-18.6 keV– Channel B, 2-18.6 keV– Channel C 18.6-2000 keV

• Results are printed out• Additional Software features

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LSC Software

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LSC H-3 Analysis

• Two protocols– LCW (30 min): LCW, Wastewater, Swipes, Oil,

etc.– Environmental (150 min): Storm water,

Groundwater

Protocol # Count Time(min)

Type ofSample

Counted

MDA(pCi/L)

1 30 LCW, oil,swipes

1000

13 150 Environmentalwater

500

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HPGe Gamma Spectroscopy

Three counting protocols:

Protocol Name Count time (sec) Type of Samplecounted

Liquid 1000 Water, Oil, Resin, Slurry

Soil 1000 Solids

Disk 1000 Air Filters, swipes

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Gammavision

• Windows based software• Sample Description File (SDF)

– Customizable analysis parameters• Calibration Files• Libraries• Job Files (Macros)• Spectrum stripping is available• Reprocess

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HPGe MDA

Radionuclide Liquid MDA for water (pCi/L)

Soil MDA for soil (pCi/g)

Be-7 1784 2.61

Co-60 270 0.52

Co-57 180 0.32

Mn-54 246 0.31

Na-22 95 0.12

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Results

• Results are entered into an Access database– Backed up daily– Relational database– Results must be approved by the Radioanalysis

manager prior to release

• Paperwork is copied and archived

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Data Entry

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Data Entry

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Rad Lab QA/QCThe Radioanalysis Laboratory has implemented thefollowing QA/QC:

• Daily source check and background check prior to use• Batch QC (for LSC)• Annual calibrations or after major system repair/upgrade• Mixed Analyte Performance Evaluation Program

(MAPEP) participation (semiannual)• For questionable samples, additional QA/QC process

such as spiking, split samples for outside independent analysis may be performed

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Daily QA

Daily QA performed prior to use

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Daily QA

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Calibrations

Calibrations performed annually , or after major repair/upgrade

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MAPEP

Mixed Analyte Performance Evaluation Program– Water and Soil Samples sent to SLAC

(semiannual)– Samples counted as field samples

• Water distilled prior to H-3 analysis• For Gamma Spec, water and soil transferred to 500 ml

Nalgene bottle– Results are checked against reference

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Nuclide% Bias for

Water% Bias for

Soil

H-3 (LSC) -1.4 N/A

Cs-137 4.9 2.4

Co-57 -1.2 2.3

Co-60 7.8 0.8

Mn-54 4.2 -0.5

Zn-65 -1.6 -3.3

MAPEP Results for Series 17 (2007) for both LSC and Gamma

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Sample StorageSamples are stored in seismic proof cabinets

(1 year max)

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Sample Disposal

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Summary

• The laboratory has the necessary equipment to support SLAC operations

• Laboratory personnel are well trained• The program and counting process are

documented• The counting protocols meet EPA 906.0• Established QA/QC program