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2.4.5 Existing radiation data

Site files, monitoring data, former site evaluation data, national, or local investigations, or emergency actions may be sources of useful site information. Existing site data may provide specific details about the identity, concentration, and areal distribution of contaminations. However, these data should be examined carefully because:

  • Previous survey and sampling efforts may not be compatible with the established historical site assessment objectives or may not be extensive enough to characterize the facility or site fully.
  • Measurement protocols and standards may not be known or compatible with the established historical site assessment objectives (e.g., quality assurance/quality control (QA/QC) procedures, limited analysis rather than full-spectrum analysis) or may not be extensive enough to characterize the facility or site fully.
  • Conditions may have changed since the site was last sampled (i.e., substances may have been released, migration may have spread the contamination, additional waste disposal may have occurred, or decontamination may have been performed).

The following existing data can be evaluated:

  • Licenses, Site Permits, and Authorizations. The facility or site radioactive materials license and supporting or associated documents are potential sources of information for licensed facilities. If a license does not exist, there may be a permit or other document that authorized site operations involving radioactivity. These documents may specify the quantities of radioactive material authorized for use at the site, the chemical and physical form of the materials, operations for which the materials are (or were) used, locations of these operations at the facility or site, and total quantities of material used at the site during its operating lifetime. Governmental agencies maintain generally files on a variety of environmental programs. These files may contain permit applications and monitoring results with information on specific waste types and quantities, sources, type of site operations, and operating status of the facility or site.
  • Operating Records. Records and other information sources useful for site evaluations include those describing on-site activities; current and past contamination control procedures; and past operations involving demolition, effluent releases, discharge to sewers or on-site septic systems, production of residues, land filling, waste and material storage, pipe and tank leaks, spills and accidental releases, release of facilities or equipment from radiological controls, and on-site or off-site radioactive and hazardous waste disposal. Some records may be or may have been classified for national security purposes and means should be established to review all pertinent records. Past operations should be summarized in chronological order along with information indicating the type of permits and approvals that authorized these operations. Estimates of the total activity disposed of or released at the site and the physical and chemical form of the radioactive material should also be included. Records on waste disposal, environmental monitoring, site inspection reports, license applications, operational permits, waste disposal material balance and inventory sheets, and purchase orders for radioactive materials are useful – for estimating total activity. Information on accidents, such as fires, flooding, spills, unintentional releases, or leakage, should be collected as potential sources of contamination. Possible areas of localized contamination should be identified.
    Site plats or plots, blueprints, drawings, and sketches of structures are especially useful to illustrate the location and layout of buildings on the site. Site photographs, aerial surveys, and maps can help verify the accuracy of these drawings or indicate changes following the time when the drawings were prepared. Processing locations – plus waste streams to and from the site as well as the presence of stockpiles of raw materials and finished products – should be noted on these photographs and maps. Buildings or outdoor processing areas may have been modified or reconfigured such that former processing areas were converted to other uses or configurations. The locations of sewers, pipelines, electric lines, water lines, etc., should also be identified. This information facilitates planning the site reconnaissance and subsequent surveys, developing a site conceptual model, and increasing the efficiency of the survey program.
    Corporate contract files may also provide useful information during subsequent stages of the radiation survey and site investigation process. Older facilities may not have complete operational records, especially for obsolete or discontinued processes. Financial records may also provide information on purchasing and shipping that in turn help to reconstruct a site’s operational history.
    While operating records can be useful tools during the historical site assessment, the investigator should be careful not to place too much emphasis on this type of data. These records are often incomplete and lack information on substances previously not considered hazardous. Out-of-date blueprints and drawings may not show modifications made during the lifetime of a facility.