Radioprotection
Ionizing radiation represents a specific danger associated with the operation of a nuclear power plant. The fundamental objective of radiological security at CNE Cernavodă is to protect people and the environment from the harmful effects of ionizing radiation.
In order to ensure effective control of the potential dangers associated with the operation of the plant, the CNE Cernavodă management promotes the highest standards in the health and safety policy of the personnel and the protection of the population and the environment.
According to the ICRP classification, the occupational radiation exposure of personnel at Cernavodă NPP falls under the category of planned exposures, as the magnitude and duration of exposures can be anticipated and reasonably managed. The management of planned exposures must take into account all relevant aspects of protection, starting with appropriate design, appropriate construction, specific aspects of radiological safety during normal operation and during shutdowns, waste management, retrofitting of nuclear facilities, etc.
The basic framework of the protection system implemented at CNE Cernavodă is the one recommended by the International Commission for Radiological Protection (ICRP) for planned exposures, being designed to prevent the occurrence of deterministic effects by keeping individual doses below the relevant thresholds and to reduce to a reasonable level the probability of occurrence of stochastic effects.
ICRP is the recognized scientific authority in the field of radiation protection, whose recommendations are used to develop international and national regulations in this field. These recommendations are periodically reviewed and updated according to the latest knowledge of the biological effects of radiation.
The ICRP recommendations from 1990 contained in Publication 60 were implemented in Romania through the Radiological Safety Norms established by the National Commission for the Control of Nuclear Activities. The principles established by the ICRP were revised in 2007 and are set out in Publication 103, which updates, consolidates and develops the 1990 principles for the control of exposure to sources of ionizing radiation.
The radiation protection policy of CNE Cernavodă is based on the general principles promoted by the International Radiological Protection Commission. These principles are:
- Justification of practices;
- Optimization of protection;
- Limiting individual exposure.
The principled framework of radiation protection includes both the scientific basis and a series of economic-social judgments, since radiation protection must ensure an appropriate standard of protection without excessively limiting beneficial practices.
According to the principle of justification, any decision that affects the radiation exposure situation must be adopted if the benefit is greater than the harm produced.
Optimizing radiation protection is based on the ALARA (As Low As Reasonably Achievable) principle for minimizing collective and/or individual exposure taking into account economic and social factors. The ALARA principle is similarly applied in all ionizing radiation exposure situations that are subject to individual dose constraints for planned exposures and reference levels for existing accident or chronic exposure situations.
According to the principle of limiting individual exposure, the total dose resulting from a planned exposure (for authorized activities) must not exceed the dose limits established by the authorities. They are established on the basis of international recommendations and apply to occupationally exposed workers and the general public. CNE Cernavodă sets administrative limits below the values of legal limits and constraints approved by CNCAN.
CNE Cernavodă applies a radiation protection policy that takes into account the particularities of the CANDU-type nuclear reactor, and the results of the COG (CANDU Owners Group) research-development program are used to solve the technical problems of radiation protection optimization.
The WANO evaluation from November 2015 identified a strong point of ensuring the radiological safety of Cernavodă CNE personnel which “through a continuous effort led to the reduction of collective exposure to a level that represents a top performance in the industry for CANDU reactors in the last 8 years , both units being ranked in the first 25% of the plants evaluated by WANO”. Following the WANO mission, no area of improvement was identified in the radiation protection area.