Radiation safety at Loviisa NPP
During the operation of the power plant, radioactive substances develop in the splitting of uranium nuclei and as the materials are activated in the neutron radiation of the reactor core. Most of the activity is within the fuel cladding. Systems that contain or may contain radioactive substances are located inside the controlled area and are closely monitored. The controlled area is enclosed, and nothing can be brought out without careful measurements.
Loviisa power plant takes all practically and reasonably possible measures in order to avoid radiation exposure to any employees, other people or the environment. Our three basic principles of radiation protection are based on the recommendations of the International Commission on Radiological Protection (ICRP). The ICRP recommendations have also been taken into account in the Radiation Act of Finland.
The radiological environmental impact of the normal operation of Loviisa nuclear power plant is very small. The annual radiation dose caused by the operation of the nuclear power plant to the residents in the vicinity is so small that it can not be measured by any meter. Therefore doses in the environment are estimated theoretically based on release information and meteorological data to a theoretical representative person who lives in the vicinity of the plant.
The radiation dose describes the health hazard caused by radiation. Its unit is sievert (Sv). The dose is often given in thousandths of sieverts, i.e. millisieverts (mSv) or in millionths, i.e. microsieverts (µSv).
Some examples of radiation doses
|Dose rate||What the rate causes|
|0,01 mSv||The radiation dose received by a patient having his/her teeth X-rayed.|
|0,1 mSv||The radiation dose received by a patient having his/her lungs X-rayed.|
|2 mSv||The annual dose of cosmic radiation received by a person working in an aeroplene.|
|3,2 mSv||The average annual radiation dose for Finns caused by indoor radon, X-ray examinations, etc.|
|20 mSv||The highest permitted dose for a radiation worker over a period of a year.|
|1000 mSv||The dose which may cause symptons of a radiation sickness (e.g. tirednss and nausea) if received within 24 hours.|
|6000 mSv||A dose that when received within under 24 hours causes radiation sickness and can be fatal.|