Experience gained over the past years by the Bureau of Radiological Health and by various states has provided the technical basis for the es­tablishment of surveillance programs in the environs of nuclear plants. The guidance for environmental surveillance of nuclear facilities provided by the Bureau of Radiological Health is applicable to those areas external to the facility’s site perimeter or fenced area, which is normally considered as the plant environs or off-site area. Accomplishment of the objectives of these programs assures continuing examination and evaluation of the en­vironment needed for the continued health and safety of the public. To ensure compatability of the surveillance data from both federal and state programs, an analytical quality control service is available through the Bureau’s area laboratories. The prime objectives of environmental surveil­lance programs for nuclear power stations are to verify the adequacy of source control, to provide data to estimate population exposure, and to provide a source of data for public information. An environmental sur­veillance program should be conducted by the facility operator. As a mini­mum, surveillance activities by the health agency should provide adequate verification of the facility’s data. This procedure allows both the health agency and the operator to have confidence in the accuracy of the re­sults.

The materials to be sampled, the frequency of sampling, and the type of analysis needed are all dependent upon the specific program ob­jectives that have been established for the facility. The extent of surveil­lance required is dependent on the nuclear facility’s location (population density, meteorology, and other environmental factors), and the quanti­ties and kinds of radioactive materials discharged. A review of the plant environment and the facility’s radioactive waste system should include an evaluation of the critical radionuclides anticipated in the normal dis­charges and the pathways through which they may disperse in the envi­ronment and thus expose the population to radiation. Because air and wa­ter are pathways through which radioactive contaminants are carried to other segments of the environment, analysis of radioactivity in these me­dia is a basic requirement in the establishment of a surveillance program. Further, an investigation of the site environs is necessary to identify mem­bers of the public most likely to be exposed and the pathways of exposure. Exposure of this critical population group can result from direct external radiation and from intake of radioactive material into the body through ingestion and inhalation.

In initiating an environmental surveillance program, it is important that radiological measurements be made and data obtained through a pre­operational survey of the plant environs. This survey will provide infor­mation related to the critical nuclides, pathways, and population groups that can be used to design the operational program. Additional informa­tion will be obtained that is useful for other purposes, among which are: (a) to provide a data base to be used in delineating any radioactive ma­terial released to the environment by the plant after initial start-up, (b) to demonstrate that the proposed surveillance system is adequate, (c) to give training and experience to the personnel conducting the survey, and (d) to provide a mechanism for gathering data for public information. Because waste discharges from a nuclear power plant operating under normal conditions should influence environmental radioactivity levels in only a limited area, preoperational samples should be taken beyond the plant’s influence for comparison with those taken near the site. This prac­tice can be continued into the operating phase and a statistical compari­son made in order to delineate possible contributions by the plant to en­vironmental radioactivity levels. It has been normal practice for preopera­tional surveys to be conducted for a period of one year before the initial start-up of a nuclear installation. In those cases where personnel are inex­perienced in surveillance operations and laboratory analysis of samples or special requirements are indicated, a longer period of time may be neces­sary in order to obtain reliable data for at least one year.

The data gathered by the environmental surveillance program during plant operation must provide the basis for source control and estimation of population dose. Complete liquid and gaseous radioactivity discharge data should be routinely provided to the health agency by the operator so that the relation between radioactive discharges and the environmental surveillance data can be established. Experience to date with nuclear power plants has shown that careful waste management, engineered safe­guards, and proper operating procedures generally result in a radionuclide concentration in waste effluents ranging from 1 to 3 per cent of the aec’s licensed discharge limits (Blomeke & Harrington, 1968).

Detection of individual accidental releases in time to take protective action is not an objective of a routine operational environmental surveil­lance program. Although protective actions can appreciably reduce the dose received if initiated quickly, the indication of a need for such actions must come from the facility in question immediately following any acci­dental release and not several days or weeks later from routine environ­mental sampling. For this reason, adequate source monitoring and control must be in effect to detect immediately significant nonroutine releases of radioactivity. In the event of such a release, it is imperative that agencies responsible for public health be promptly notified so they can initiate emergency monitoring programs with the objective of ascertaining wheth­er or not there is a need for protective actions. A special preplanned doc­umented emergency monitoring system is required in order to be able to assess adequately any public health hazard in the event of a major acci­dental release of radioactivity to the off-site area.

The surveillance described here pertains to the operation of nuclear installations under normal operating conditions and is not intended to ap­ply to an accident situation. The recommended general program shown on page 64 (Terrill et al., 1968; Weaver & Harward, 1967) serves as a guide for the development of an environmental monitoring program and is considered adequate from a public health standpoint. However, with the rapid expansion of the nuclear power industry, the number of individ­ual facility monitoring programs will increase. Therefore, the Bureau of Radiological Health is updating these surveillance recommendations, on the basis of field studies which are being carried out through the Bureau’s area laboratories to obtain basic data needed to define upgraded surveil­lance requirements. Because of the planned increase in the nuclear power industry, it is important to develop a coordinated nationwide surveillance

program to meet public health responsibilities for estimating population exposure. This type of program must be developed with participation by industry, states, and federal agencies in order to meet national objectives of protection of the public health and preservation of environmental qual­ity.