Nuclear waste is hazardous

What is nuclear waste?

By splitting the atom we are able to release a tremendous amount of energy. In the uncertain times of the Second World War, this power was first developed to make bombs. However, as the world slowly settled after the horrors of the Hiroshima and Nagasaki bombings, other uses for this power were explored. One of them was to meet our growing needs for electricity.

Thus nuclear energy rose to the occasion in the 1950s, providing mankind with seemingly unlimited energy. However, it soon became apparent that what was thought to be the grand solution to our energy problem, in fact created another one: a highly radioactive bi-product that still to this day is the most hazardous environmental waste known to man.

Today there are two general kinds of nuclear waste: the low- and intermediate-level waste (LLW/ILW) and the high-level waste (HLW), such as spent nuclear fuel. The waste is graded according to its level of radioactivity. MKG (The Swedish NGO Office for Nuclear Waste Review) primarily reviews the process of finding the best possible final repository for the spent nuclear fuel.

 

Final repository for spent nuclear fuel

To come in contact with spent nuclear fuel will lead to an almost instant death. And although the deadly radiation diminishes over time, the nuclear waste will remain hazardous for hundreds of thousands of years. This is indeed a very long a time to imagine, but in order to fully understand what must be asked of a final repository for this waste-product of our time, grasping the magnitude of the time frame is essential.

Several hundreds of thousands of years is a very long time. This means that almost everything that could potentially compromise the safety of the final repository is likely to happen. These threats include anything from the canisters starting to leak its radioactive content into its surroundings, to a man made breech; intentional or otherwise. For instance, plutonium in the spent nuclear fuel can be converted into devastating weapons of mass destruction, making it highly sought after by those wanting to do harm. However, this immense time frame also means that the final repository has to be able to withstand the enormous geological strains of repeated ice ages. As the ground buckles under the massive ice, earthquakes, rock and stress movement as well as permafrost will pose a significant threat to any repository. In Sweden, we run the risk of experiencing up to three ice ages in the next 100 000 years alone.

These are all aspects that we have to consider when deciding on a final resting place for our spent nuclear fuel, and needless to say: the decision has to be right. There is no going back; no second chances. Therefore we must not haste into a decision that will place a radioactive burden on our future generations due to a flawed method of choice, but carefully evaluate our options in an unbiased and critical manner.

 

Not only spent nuclear fuel

When thinking of radioactive waste, what usually comes to mind might be the aforementioned spent nuclear fuel. This is most reasonable as this particular type of radioactive waste is the most harmful kind to us humans and to the environment. However, as previously mentioned there are other kinds of nuclear waste that also needs attending to; the low- and intermediate-level waste.

Low-level waste, or LLW, is mostly produced by hospitals and industry, and mainly consists of discarded rags, clothes, tools and filters. Generally, this type of waste requires no particular shielding and needs only to be stored for about 40 years.

Intermediate-level waste, or ILW, is mainly produced by the nuclear power industry’s day-to-day operation. It requires shielding to prevent its hazardous radioactivity from affecting us and the environment. It also needs to be stored for at least 500 years.

Today, the low- and intermediate-level waste is being stored in an underground rock shelter at a depth of 50 meters. The storage is located in Forsmark and it is the intention of the power industry’s nuclear waste company SKB to expand this storage in order to accommodate future demands.

Alternativa lokaliseringar

Vid val av ett slutförvar som är säkert i hundratusentals år så är inte bara valet av metod av stor vikt. Även en lämplig lokalisering är viktigt. Ett exempel på vad som kan styra säkerheten av ett förvar är in- och utströmningen av grundvatten. Hur grundvattenströmningen ser ut beror på lokaliseringen av förvaret.

Djupa borrhål

När en verksamhetsutövare ansöker om att starta en verksamhet så ska denne enligt miljöbalken presentera alternativa metoder till att uppfylla det ändamål som projektet syftar till.

Kapplöpning efter uran i Sverige

Som en följd av att oljepriset har stigit och intresset för kärnkraft har ökat tredubblades uranpriset under 2004 och 2005. Därför har intresset för uranbrytning i Sverige åter väckts till liv efter att ha legat nere sedan mitten av 1980-talet. Före den tiden genomfördes undersökningar i stora delar av Sverige, framför allt i Norrland.

Långsiktig säkerhet

Använt kärnbränsle är farligt i minst 100 000 år. Under denna tid måste avfallet hållas avskilt från människor och miljön. För att uppnå detta måste den långsiktiga säkerheten beaktas redan vid planerandet av ett slutförvar. Säkerhetsaspekter som måste beaktas är till exempel slutförvarets hållbarhet under en istid och att avfallet inte används i icke fredliga syften.

Beslutsprocess

Kärnavfallsbolaget SKB skickade den 16 mars 2011 in ansökningar för ett slutförvarssystem för använt kärnbränsle. Ansökningarna ska prövas både mot kärntekniklagen och mot miljöbalken. Det är Strålsäkerhetsmyndigheten respektive Miljödomstolen som bereder ärendena.

Hanteringen av industrins forskningsprogram, Fud-programmet, vart tredje år enligt kärntekniklagen

Var tredje år ska kärnkraftsindustrins kärnavfallsbolag Svensk kärnbränslehantering AB, SKB, enligt kärntekniklagen och kärnteknikförordningen redovisa sitt kärnavfallsarbete i ett dokument till Statens kärnkraftinspektion, SKI, sedan den 1 juli 2008 Strålsäkerhetsmyndigheten. Dokumentet har fått benämningen Fud-rapport som står för forskning, utveckling och demonstration.

Kopparkorrosion

Industrins KBS-metod bygger på att konstgjorda barriärer av koppar och lera ska isolera avfallet under hundratusentals år. Avfallet ska läggas i en kopparkapsel som ska bäddas in i lera och som sedan ska förvaras i gruvgångsliknande tunnlar på omkring 500 m djup i grundvattenförande berg.

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