The safety procedures applied in nuclear power plants and other nuclear sites include exhaustive surveillance of the radiological impact on the environment. The surveillance networks set up throughout the Spanish territory are used to carry out samplings and analyses in order to ensure that the area is safe for the population, flora and fauna in the territory, taking into account that there is a level of natural radiation.
Radiological surveillance consist of evaluating and monitoring the environmental radiological impact of nuclear and radioactive sites, as well as the radiological quality of the environment throughout the national territory.
With this purpose, the Spanish Nuclear Safety Council (CSN) uses a system of networks and radiological surveillance programs.
Their main goals are the following:
- Detect the presence and monitor the evolution of radioactive elements and the levels of environmental radiation.
- Determine which are the causes of the possible increments of radioactive levels in the environment.
- Calculate the potential radiological risk for the population and, in this case, establish the proper precautions and measures.
- Verify the compliance with the requisites set by the site authorizations.
- Guarantee compliance with the legal and regulatory requisites imposed on the sites.
- Verify the suitability of the effluent surveillance program (in such a way that any undetected leaks may be detected) and the transference models of radionucleids in the enviroment.
This sytem is integrated by several surveillance networks:
Radiological surveillance network around nuclear power plants and sites in the nuclear fuel cycle
Environmental Radiological Surveillance Programs (PVRA) are managed by the owners of nuclear sites, and the CSN establishes the requisites that these owners must comply with in the surroundings during the site's various life stages. The CSN carries out periodic inspections and establishes systematic control programs in order to guarantee that the area remains safe.
During the inspections, samples from the site's influcence areas are collected. Most samples are collected in the main channels of transference of radioactive elements to the population. The surveillance system uses various safeguards, such as an analysis of the samples by two different labs in order to check the degree of concordance of the results obtained by both.
Every year, the site owners send the results of the PVRA to the Council. These results can be reviewed in the Map of Environmental Radiological Values (in Spanish).
National radiological surveillance network, not associated to sites related to the nuclear fuel cycle (REVIRA)
This network makes it possible to get to know the radioactivity levels in the air, water and soil of basic food such as milk and a complete diet. It is composed by a Network of Automatic Stations (REA) that survey atmospheric radiation in real time. It is integrated by automatic stations with instrumentation to carry out a continuous measurement of radiological variables (gamma dose index, radon concentration, radioiodines, alpha and beta emitters in the air) and weather variables (temperature, relative humidity, wind direction and speed, precipitation and atmospheric pressure).
The average daily gamma dose indexes of the automatic surveillance stations scattered around the Spanish territory can be accessed in the REA map of enviromental radiological values (in Spanish). These stations are in operation since 1992.
Sampling station network (REM)
In REM, surveillance is carried out by taking samples and then doing a radiological analysis. The method is similar to that of PVRA, with the difference that the surveillance is done by CSN with the cooperation of a series of Spanish laboratories and institutions.
It is composed by two complementary networks: the dense network, with numerous points distributed around the territory, and the high sensibility onetwork, where measuring is done in very few points. Both networks carry out measures corresponding to two types of programs:
- The atmosphere and terrestrial environment surveillance program, with the objective to measure radiactivity in soils, drinking water, milk and standard diet.
- The coastal and continental water environment surveillance program, with the objective to inspect the radiological quality of rain waters in the various river basins, as well as of ocean water in different points of the coast.
The results may be viewed in the PVRA REM Map of environmental radiological values (in Spanish).
Specific environmental radiological programs
Apart from the aforementioned programs in surveillance networks, in Spain there are also specific programs in areas with residual contamination due to past practices.
At these sites, the necessary measures to eliminate all contamination and risks have already been taken, but the yearly environmental radiological surveillance plans are still in place.