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3.5.9 Sample tracking/record keeping

Contents
3.5.9.1 Field tracking considerations
3.5.9.2 Photography
3.5.9.3 Sample labelling and transport
3.5.9.4 Transfer of custody
3.5.9.5 Laboratory tracking

Sample tracking refers to the identification of samples, their location, and the individuals responsible for their custody and transfer of the custody. This process covers the entire process from collection of the samples and remains intact through the analysis and final holding or disposal. It begins with the taking of a sample where its identification and the designation of the sample are critical to being able to relate the analytical result to a site location.

Tracking samples from collection to receipt at the analytical laboratory is normally done through a Chain of Custody process, and documented on a Chain-of-Custody (COC) record. Once samples are received by the laboratory, internal tracking (e.g., Chain-of-Custody) procedures should be in place and codified through standard operation procedures that assure integrity of the samples. Documentation of changes in the custody of a sample(s) is important. This is especially true for samples that may be used as evidence to establish compliance with a release criterion. In such cases, there should be sufficient evidence to demonstrate that the integrity of the sample is not compromised from the time it is collected to the time it is analyzed. During this time, the sample should either be under the positive control of a responsible individual or secured and protected from any activity that could change the true value of the results or the nature of the sample. When this degree of sample handling or custody is necessary, written procedures should be developed for field operations and for interfacing between the field operations and the analytical laboratory. This ensures that a clear transfer of the custodial responsibility is well documented and no questions exist as to who is responsible for the sample at any time.

3.5.9.1 Field tracking considerations

Field personnel are responsible for maintaining field logbooks with adequate information to relate the sample identifier (sample number) to its location and for recording other information necessary to adequately interpret results of sample analytical data.

The sample collector is responsible for the care and custody of the samples until they are properly transferred or dispatched. This means that samples are in their possession, under constant observation, or secured. Samples may be secured in a sealed container, locked vehicle, locked room, etc.

Sample labels should be completed for each sample using waterproof ink.

The survey manager or designee determines whether or not proper custody procedures were followed during the field work, and decides if additional sampling is indicated.

If photographs are included as part of the sampling documentation, the name of the photographer, date, time, site location, and site description should be entered sequentially in a logbook as the photos are taken. After the photographs are developed, the prints should be serially numbered.

3.5.9.2 Photography

Photographs provide a valuable record of a contaminated land survey. However, there are often significant restrictions to the use of cameras on nuclear-licensed sites, defense and industrial sites. Prior to use of a camera on these sites, permission should be sought from the site operator. Ideally photographs should be taken of:

  • Contaminant source areas.
  • All sampling locations before sampling.
  • All sampling locations during sampling.
  • All sampling locations after sampling and reinstatement.
  • Trial pit walls.
  • Any exposed in-situ geological materials.
  • Core samples prior to them being divided up for analysis.

3.5.9.3 Sample labelling and transport

Samples should be clearly labelled in a manner that cannot be removed during handling. The labels should include the following minimum information:

  • Location number.
  • Depth interval.
  • Date of sampling.
  • Hazard information.

Transport of samples to the laboratory should take place as soon as possible after sample collection to minimise the potential for degradation to occur. Advice on storage conditions should be sought from the analyst.

Radioactively contaminated samples containing greater than 70 Bq/g total radioactivity become subject to the radioactive substances (road transport) regulations [ADR]. If this is the case, samples are required to be labelled, packaged and transported in accordance with the regulations. However, the total radioactivity of a sample is not known until is analysed. If it is suspected that some samples may contain greater than 70 Bq/g of radioactivity, it may be necessary to undertake onsite screening analysis, for example using a portable gamma spectrometer, to determine the appropriate method of transport. If this is not possible, then samples should be transported in accordance with the requirements of the radioactive substances (road transport) regulations [ADR].

3.5.9.4 Transfer of custody

A chain of custody document should be prepared for each sample or batch of samples and should record collection in the field, off-site consignment to the testing laboratory and receipt by the testing laboratory:

  • All samples leaving the site should be accompanied by a Chain-of-Custody record. This record documents sample custody transfer from the sampler, often through another person, to the laboratory. The individuals relinquishing the samples should sign and date the record. The record should include a list, including sample designation (number), of the samples in the shipping container and the analysis requested for each sample.
  • Shipping containers should be sealed and include a tamper indicating seal that will indicate if the container seal has been disturbed. The method of shipment, courier name, or other pertinent information should be listed in the Chain-of-Custody record.
  • The original Chain-of-Custody record should accompany the samples. A copy of the record should be retained by the individual or organization relinquishing the samples.
  • Discuss the custody objectives with the shipper to ensure that the objectives are met. For example, if the samples are sent by mail and the originator of the sample requires a record that the shipment was delivered, the package should be registered with return receipt requested. If, on the other hand, the objective is to simply provide a written record of the shipment, a certificate of mailing may be a less expensive and appropriate alternative.
  • The individual receiving the samples should sign and date the record. The condition of the container and the tamper indicating seal should be noted on the Chain-of-Custody record. Any problems with the individual samples, such as a broken container, should be noted on the record.
  • Subsequent to testing, the surplus portions of the samples may be returned to the site operator (for long term archiving, storage or disposal) or may be disposed by the principal contractor or analytical testing laboratory in accordance with national or European legislation. The chain of custody document should record these transfers. The disposal of radioactively contaminated samples should be considered as part of the site characterisation works waste management plan in Section 2.
  • A copy of the Chain-of-Custody document should be kept in the project file.

3.5.9.5 Laboratory tracking

When the samples are received by the laboratory they are prepared for radiochemical analyses. This includes the fractionation of the sample into aliquots. The tracking and Chain-of-Custody documentation within the laboratory become somewhat complicated due to the fact that several portions of the original sample may exist in the laboratory at a given time. The use of a computer based laboratory information system can greatly assist in tracking samples and fractions through the analytical system.
The minimal laboratory tracking process consists of the following:

  • Transfer of custody on receipt of the samples (original Chain-of-Custody form is retained by the laboratory and submitted with the data package for the samples).
  • Documentation of sample storage (location and amount).
  • Documentation of removal and return of sample aliquots (amount, date and time, person removing or returning, and reason for removal).
  • Transfer of the samples and residues to the receiving authority (usually the site from which they were taken).
    The procedure for accomplishing the above varies from laboratory to laboratory, but the exact details of performing the operations of sample tracking should be contained in a standard operating procedure (SOP).