Protective Action Guides

EPA, Manual of Protective Action Guides and Protective Actions for Nuclear Incidents, EPA 400-R-92-001, U.S. Environmental Protection Agency, Washington, D.C., 1992. 

The Food and Drug Administration (FDA) develops standards for radioactive material concentrations in food (FDA 1998), and medical devices used in radiation therapy (FDA 1997). The FDA recently updated its guidance document that presents recommended action levels for radionuclides in foods, both domestic and imported (FDA 1998). These derived intervention levels (DILs) are estimated levels in food that could lead to individuals receiving a radiation equivalent dose equal to the FDA protection action guide (PAG) that is set as the more limiting of either 0.5 rem (5 mSv) for committed effective dose or 5 rem (50 mSv) committed dose equivalent to any individual tissue or organ. Table 8-2 presents the most restrictive DILs for strontium. 

Derived intervention levels (DIL) are concentrations of radioactivity in food whose consumption would deliver a committed effective dose equivalent equal to the most limiting of the protection action guides (PAGs) developed by FDA (1998). 

As will be seen later (Section VI), any dose can be associated with an approximate value of morbidity risk and mortality risk derived from evidence drawn from medical radiology, evidence of atomic bomb late casualties, and other sources (e.g., animal experiments). We shall find that the above-mentioned ERL s or Protective Action Guides have associated with them morbidity-mortality risks generally of the order 10 to 10 and looking ahead again to Section VI, this is significant but small compared to the overall total death risk of the average person, which is about 10 per annum even in the prime of life (say 5-45 years of age). 

Federal Radiation Council, Background Material for the Development of Radiation Protection Standards, Rep. No. 5 (1964) Background Material for the Development of Radiation Protection Standards Protective Action Guides for strontium 89, strontium 90 and caesium 137, Rep. No. 7 (1965). Both from U.S. Govt. Printing Office, Washington, DC. 

For purposes of emergency planning, EPA-520/1-75-100 provides Protective Action Guides (PAGs) for exposure to airborne radioactive materials, contaminated foodstuff or water, and contaminated property or equipment. (Ref. 6)... 

Protective Action Guides for Exposure to Airborne Radioactive Materials ... 

Protective Action Guides for Exposure from Material Deposited on Property or Equeipment... 

Intervention or action levels are values, in terms of radiation dose or concentrations in food, that are used to determine when protective actions should be taken to meet these objectives. Different countries and organizations use different names for these levels. For example, in the United States intervention levels are referred to as protective action guides (PAG) and action levels for food as derived intervention levels (DIL). 

C Food and Drug Administration (FDA) protective action guides (PAGs) 5.1-17... 

Atmospheric release (Ci) necessary under poor meteorological conditions to result in protective action guide levels at 1 mile 5.1-18... 

The public can usually be protected from an uncontrolled release of radiological material only by some form of intervention (e.g. evacuation) that disrupts normal living. Such intervention is termed protective action. This subsection presents basic radiation protection objectives and protective action guides that establish the magnitude of radionuclide releases requiring early protective action. A more complete discussion of protective actions that may be appropriate during or after a severe reactor accident is presented in Section 5.4. 

A Protective Action Guide (PAG) is the projected dose to reference man, or other defined individual, from an unplanned release of radioactive material at which a specific protective action to reduce or avoid that dose is recommended The Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) have established PAGs that are applicable to severe reactor accidents. These PAGs must be considered in licensees emergency plans and decisions as discussed in Sections 5.3 and 5.4. 

It is important to emphasize that protective action guides are based on projected doses— future doses that can be avoided by the specific protective action being considered. Doses incurred prior to initiation of the protective action should not normally be included. Similarly, in considering early protective actions such as evacuation or sheltering, doses that... 

It is not obvious in examining a specified radionuclide source term what the potential health impact would be to the public. Based on the compilation of a number of consequence analyses, however. Table 5.1-4 shows the number of curies of radioiodine (1-131) or noble ga es that would have to be released to the atmosphere to result in doses equal to the protective action guides under average meteorological conditions. It is instructive to compare the inventory of radionuclides in various plant locations the amounts that would have to be released to induce doses equal to the protective action guide levels. 

Table 5.1-5 summarizes annual releases of noble gases and radioiodine during normal light water reactor operation. As indicated in the table, a 1-hr release rate more than 1(X),(XX) times normal release rates would be required for protective action guides to be exceeded. 

Comparisons of Tables 5.1.2 and 5.1.4 show that the release of even a very small fraction of the core radioactive material inventory to the atmosphere could result in doses exceeding the protective action guides near the site. However, only the core, spent-fuel storage pool, and the reactor coolant contain the requisite inventory of radionuclides. Accidents not involving one of these three regions (e.g., gas-decay tank rupture) should not result in off-site doses in excess of the Environmental Protection Agency protective action guides. ... 

Dose levels ten or more times higher than the protective action guides are required to induce early injuries or fatalities. Only the reactor core contains sufficient radioactive material and energy (e.g., decay heat) to result... 

EPA Manual of Protective Action Guides and Protective Actions for Nuclear Incidents, 1980. 

Factor by which normal release rate would have to be increased to give a 1 hour release that would exceed federal protective action guide level 1.5x10 6x10 ... 

In this example, the early doses (cloud shine and inhalation) are not sufficient to cause early injuries, but they do exceed Environmental Protection Agency protective action guides. Other source terms have been postulated (no matter how unlikely) that could cause early injuries close to the plant resulting from cloud shine and inhalation. This shows the importance of early protective actions. For large source terms like PWR 4 involving a puff release of... 

In virtually all cases, the greatest effluent concentrations occur within the first 2 to 3 miles. Therefore, independent of the size of the release, the greatest need for protective actions most likely will be within 2 to 3 miles of the plant. For large releases, these actions will be to prevent early deaths and, for lesser releases, to keep doses below Environmental Protection Agency protective action guides. 

Events are in progress or have occurred that involve an actual or potentially substantial degradation of the level of safety at the plant. Any radiological releases are expected to be limited so that resulting exposures would be small fractions of the U.S. Environmental Protection Agency (EPA) Protective Action Guides. 

Events are in progress or have occurred that involve actual or likely major failures of plant functions needed for protection of the public. Radiological releases, if any, are not expected to result in doses exceeding Environmental Protection Agency Protective Action Guide levels, except possibly near the site boundary. 

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