Disposal of Nuclear Waste

Nuclear waste consists of products that contain radioactive material. There are three types of radioactive decay: alpha decay, beta decay and gamma decay. An alpha particle is made up of two protons and two neutrons combined. It can easily be stopped: a paper sheet does the trick. Beta particles can be positive or negative,  depending on how they were transformed. It can be stopped by an aluminum sheet. 

Gamma decay generally occurs when a nucleus has just gone through an alpha or beta decay and is left in an excited state with an excess of energy. To lose this energy, it releases gamma rays. This gamma particle does the most damage to materials and can only be stopped by a thick wall of concrete.

If this gamma ray comes in contact with a living being it can cause burns, cancer and genetic mutations. It is considered the most dangerous form in cases of exterior exposure. When inhaled or consumed, alpha particles are even more dangerous. This is why the management of nuclear waste is extremely important. 

Radioactive waste is classified using two criteria: level of radioactive emission and longevity (the duration of the radioactivity of the product which is measured in “half-life”). 

Short lived gamma debris can take less than 30 years to eliminate half of radioactive rays.
Belgium classes waste in three categories.
·      Type A: low or medium activity and a short half-life (ex: protection material, waste from research center, medical products, etc…)
·      Type B: low or medium activity and a long half-life (ex: waste from nuclear fuel …)
·      Type C: high activity and a long half-life (ex: nuclear fuel…)

In Belgium 80 % of waste is of type A, 19 % is of type B and 1 % is of type C. The problem is that long lasting waste can “live” up to centuries.

After the waste separation, it is compacted. These residues are locked in barrels. The C type is also vitrified before that. Right now this waste is stored in concrete Belgoprocess buildings, which are isolated from the population. The problem is that these buildings will not last for centuries. This is why the European Underground Research Infrastructure for Disposal of nuclear waste in Clay Environments (Euridice) was created.
This research program is looking into burying type B and C waste. Type A waste will be stored on the surface. The program for type C waste in Belgium is to bury it in clay lands, with a lot of protection.

 The plan is to bury it so deep with so much protection that if and when the radiation reaches the surface it is no longer harmful to the living anymore.

To make sure that this plan is possible the Hades laboratory was created, where the capacity of the elements envelopping the barrels is tested underground. This program should permit future generations to not have to worry about our present waste.

Each country has different plans for their nuclear waste depending on the soil they have and their production of nuclear debris. The management of these products is very important as they have a major impact on life.

By Mignot Sarah

Edited by Gustavs Zilgalvis

No comments:

Post a Comment