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Q:  Is radioactive waste dangerous?

A.  Radioactive waste is categorised according to the hazards associated with the different waste types.  Therefore, low-level waste does not pose a significant radiation hazard, whereas high-level waste is potentially dangerous and needs to be properly contained and shielded.  

Radioactive waste differs from other kinds of waste in that it emits energy in the form of radiation.  This energy appears as  alpha, beta and gamma radiation.  Damage to living tissue can be caused if sufficient quantities of alpha, beta or gamma radiation interact with genetic material within the cells of our bodies. Whether the radiation causes us any harm depends on the quantity of the radiation, how energetic it is and what part of the body is affected

The radioactivity produced by radioactive waste is therefore potentially dangerous and are categorised into different waste types according to the radioactivity they produce.  Low-level waste on the one hand, does not pose a significant radiation danger, whereas high-level waste on the other hand is potentially dangerous and needs to be properly contained and shielded from living organisms.

The radiation dose describes the health hazard caused by radiation. The dose unit is Sievert (Sv). The dose is often given in thousandths of Sieverts, i.e. millisieverts (mSv) or in millionths, i.e. microsieverts (ÁSv).

The global background radiation is measured at 2.4 mSv and South Africa's average is close to this.

Some examples of radiation dose :

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 aeroplane
4     mSv The average annual radiation dose for South Africans caused by indoor radon, X-ray examinations, etc
100  mSv The highest permitted dose for a radiation worker over a period of five years
1000 mSv The dose which may cause symptoms of a radiation sickness (e.g.  tiredness and nausea) if received within 24 hours
6000 mSv The dose which may lead to death when received all at once


At Pelindaba and Vaalputs the probability of a serious radiation exposure is small.  Nonetheless, the risk of accidents exists. Therefore, precautions need to be taken to prevent such  occurrences .  The radiation exposure of NECSA workers is monitored regularly and measures taken when deviations from norm occur, such as withdrawing workers from their place of work for a specified period of time.  This information is available from NECSA's Risk Management Division.