IAEA Post Graduate Educational Course in Radiation Protection and Safety of Radiation Sources
Intervention for Chronic and Emergency Exposure Situations
Monitoring in a Nuclear or Radiological
Emergency
Field Sampling
Lecture

 One of the method to estimate the contamination of environment is to take samples and then by analytical techniques determine specific radionuclide activity concentrations
 The lesson presents an overview of basic strategy, methods and techniques of field sampling
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 Sampling objectives and strategy
 Sampling methods and techniques
 Air sampling
 Soil sampling
 Water sampling
 Milk sampling
 Human food sampling
 Pasture sampling
 Sediment sampling
 Summary
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 Representative sampling enables to determine the level and extent of contamination of ground, water, foodstuffs, vegetation, etc.
 Samples protocols should be agreed in advance by all organisations which, in an emergency, could carry out environmental measurements
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 In general:
 to assist in the decision
WHETHER, WHEN and
WHERE to apply protective actions
 In specific:
 to determine level and extent of contamination of air, ground, water, foodstuffs, vegetation, etc.
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 The design of a sampling programme will be determined by:
 The extent and the scale of the accident
 The availability of the qualified sampling teams
 The composition of the released radionuclides
 The demographics of the environment in terms of agricultural practices and population distribution
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Sampling is required during all phases of a major accident
In the early phase of an accident involving airborne contamination the sampling priorities are as follows:
 in-plume air sampling during the release
 soil sampling after end of the release or after plume passage
 sampling of contaminated food, water and milk after end of the release or after plume passage
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 In sampling it is important:
 to take representative samples
 that samples are taken at locations representative of the area
 that sampling techniques are consistent between sampling teams, and
 that sampling protocols are agreed in advance by all organisations which in emergency, could carry out environmental measurements
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 Samples can be
 Assessed in the field
 With portable instrumentation, and/or
 In mobile laboratories or
 Returned to a specialist laboratory for sample preparation and radionuclide analysis
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 Purpose
 Discussion
 Precautions/Limitations
 Equipment/Supplies
 Steps
 Attachments
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 Procedures themselves are structured as follows:
 Prior to being dispatched
 Sample location identification
 Sampling
 Sample packaging and labeling
 Contamination control
 Sample delivery
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 Receive an initial briefing and initial assignments from the Environmental
Analyst/Radiological Assessor
 Obtain appropriate equipment using appropriate checklists
 Check the instruments
 Conduct the radio check when leaving for the assignment
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 Conduct a GPS check when leaving for the assignment
 Wrap the survey instruments in plastic to prevent contamination
 Set the alarms of self-reading dosimeters
 Wear appropriate personal protective equipment
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Find the sampling location requested by the
Environmental Analyst/Radiological Assessor
If GPS is available take position of the location and record it in appropriate sampling Worksheet, otherwise
Identify it and mark it on the map and then record it in appropriate sampling Worksheet
Take ambient dose rate at the location and record it in appropriate sampling Worksheet
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 Place the sample in a plastic bag
 Seal the bag
 Label the bag with sample code
 Record the code and all other needed data in appropriate worksheet
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 Perform personal and equipment contamination check
 Request assistance from Personal
Monitoring and Decontamination Team
 Rinse sampling equipment with clean water from a known source and dry before reuse
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 Arrange for delivery of the sample(s) with completed sampling worksheet(s) to the Sample Analyst
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Cautions
 NO sample is worth the loss of life or limb
 Always be aware of the hazards that you may encounter in the field and take the necessary precautions
 Never attempt any field activities without the appropriate safety equipment
 Always know how to use that safety equipment
 Team members should be aware of radiation protection measures and turn back guidance
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 Purpose:
 to gather air samples for in-situ assessment and subsequent laboratory analysis
 to provide data on airborne activity concentrations
 Method: pumping air through the air filter
 Performed by: Air Sampling Team
 Special precautions: see next slide
 Equipment: air sampling equipment, survey meter and worksheet
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Precautions / Limitations
 Special cartridges are only used when presence of radioiodine is expected
 Exposure to external radiation as well as inhalation and surface contamination hazards are possible
 Team members should refrain from any activity that might inadvertently contribute to the inhalation or ingestion of particulates while in the field or working in sample receipt or processing areas
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 Choose particulate filter or aerosol cartridge and mount it (note the flow directions on the cartridge, if applicable)
 Set the air sampler in a tripod or stand or on the hood of a vehicle at about 1 m high
 Turn the sampler on and record the starting date, time and volume reading / flow rate in Worksheet
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 Perform air sampling for about 10 minutes or the time specified by the EA/RA
 During the sampling take ambient dose rate measurements - record the average value
 Record time and volume reading / flow rate, then turn sampler off
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 Using the appropriate contamination monitor, take a background reading well away from the sample
Record the background on Worksheet
Hold the filter face a few millimeters from the end of the contamination monitor probe and take reading
Record the measurement
Report the location, sample number, filter reading, instrument background reading, instrument calibration factor and details of air sample time on and off and air sample flow rate to the EA/RA
Module X.7 - Monitoring in a Nuclear or Radiological Emergency 24

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Purpose:
 To gather samples of potentially contaminated soil
 To measure gamma/beta dose rates at sample location
Method: depends on the expected distribution of the contaminant
Technique: depends on the type of soil
Performed by: Environmental/Ingestion Sampling Team
Special precautions: see next slide
Equipment: soil sampling equipment, survey meter and worksheet
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Precautions/Limitations
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Ground contamination may vary significantly from place to place (hot spots)
Local dose rate averages are helpful in choosing a representative sampling location
Soil sampling is to be done after a release has ended and after plume passage
Exposure to external radiation is possible but inhalation hazards may only be due to resuspended materials
Team members should be aware of turn back guidance
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 If the soil is covered with grass, weeds, or other organic material, clip closely and treat as a vegetation sample - bag separately
 Put on vinyl gloves
 Take the sample from a known area and well-defined depth, e.g. 5 cm and place it in a plastic bag
 Rinse the tools used for sample handling with clean water from a known source and dry with fresh paper tissue or similar
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 Purpose:
 to collect samples of potentially contaminated water
 Method: depends on the type of water
 Performed by: Environmental/Ingestion
Sampling Team
 Special precautions: see next slide
 Equipment: water sampling equipment, survey meter and worksheet
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Precautions / Limitations
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Since the sampling is supposed to be done after ending of a release and after plume passage no significant inhalation hazard is to be expected
Nevertheless, there can be external radiation and surface contamination hazards
Most likely the risk of contamination and cross contamination of samples is of main concern
In all sampling, the container should be rinsed with some of the water to be sampled and that water should be discarded before the container is filled
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 Obtain water sample from the well
 Fill sampling container
 Record the date and time of sampling in worksheet
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 Use a bucket to collect the water to fill the sampling container
 Avoid areas of high turbidity or high sediment
 Avoid stirring up sediments and including them in the sample
 Record the date and time of sampling in worksheet
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Collect precipitation using rain collection device with known collection area
Measure ambient dose rate
Record date and starting time of the collection and ambient dose rate in the worksheet
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 When returning to collect a rain sample, measure ambient dose rate again and record it in worksheet
 Using the graduated cylinder measure the total volume of rain
 Transfer to the sampling container until full or less if that’s all that was collected
 Record date and ending time of collection and total volume in worksheet
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 Collect tap water in the sampling container
 Record date and time of sampling in worksheet
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 Purpose:
 to collect samples of potentially contaminated milk
 Method:
 Performed by: Environmental /Ingestion
Sampling Team
 Special precautions: see next slide
 Equipment: milk sampling equipment, survey meter and worksheet
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Precautions / Limitations
 No special personal radiation protection measures are expected in these samplings
 The risk of contamination and crosscontamination of samples is of main concern
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 Fill the container with milk - take care to prevent contamination and crosscontamination
 Refrigerate samples if they will be delivered to the laboratory the same day, otherwise add preservative
 Rinse all devices used in the sampling with clean water and dry with fresh paper tissue or similar
 Label the bottles with the sampling code and record it in worksheet
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 Purpose:
 to collect potentially contaminated vegetables and fruit samples for laboratory analysis
 Method:
 Performed by: Environmental/Ingestion
Sampling Team
 Special precautions: see next slide
 Equipment: food sampling equipment, survey meter and worksheet
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Precautions / Limitations
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Only top portions of the plant are collected or edible portions (surface contamination of vegetables is the deciding factor determining consumption restrictions)
Sampling should be done only after a release has ended and after plume passage
External exposure and surface contamination are possible but inhalation hazards may only be due to re-suspended materials
Team members should be instructed on turn back guidance
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Collect enough sample to yield at least 1 kg of edible portion - select samples on basis of the readiness for harvest
Collect the green and leafy portions of the plant, not the roots and stems, unless that is the edible portion
It is important to collect the vegetables and any moisture that may be on them, whether frozen or not
After each sampling, rinse sampling tools with clean water and dry with fresh paper tissue or similar
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 Purpose:
 To collect animal pasture samples for laboratory analysis
 Method:
 Performed by: Environmental/Ingestion
Sampling Team
 Special precautions: see next slide
 Equipment: feed sampling equipment, survey meter and worksheet
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Precautions / Limitations
 Sampling is supposed to be done after a release has ended and after plume passage
 External exposure and surface contamination are possible but inhalation hazards may only be due to re-suspended materials
 Team members should be instructed on turn back guidance
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Mark the area to be sampled (1 m 2 , or larger) and record it in worksheet
Collect at least 1 kg of the sample from the pasturage down to 2 cm above the ground, preferably a grassy type of vegetation
Collect the green or leafy portions of the plant
Note and expand the area until 1 kg is collected, if necessary
Care should be taken not to include soil
After each sampling rinse sampling tools with clean water
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 Purpose:
 To gather samples of potentially contaminated sediments
 Method:
 Performed by: Environmental/Ingestion
Sampling Team
 Special precautions: the risk of personal contamination
 Equipment: sediment sampling equipment, survey meter and worksheet
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 In a river a sample should be collected in a area of calm water or slower flow to avoid turbulence caused by obstructions (for example, large stones)
 Take the sediment sample according to specific procedure
ECMAN DREDGE
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 This lesson has presented basic sampling methods and techniques
 Representative samples should be taken at locations representative of the area
 Sampling protocols and procedures should be agreed in advance
 Certain precautions should be taken while sampling in contaminated area
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INTERNATIONAL ATOMIC ENERGY AGENCY
Generic Procedures for Monitoring in a
Nuclear or Radiological Emergency
IAEA-TECDOC-1092, Vienna (1999)
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