Urenco Almelo (fully booked)
22 November 2013
ALMELO - Around 14:00, it's a busy time in front of the gate. We just assume they experience this more often at Urenco, only this feels like a special occasion. After all, already almost half of the registered engineers cannot wait to get inside. When we report to the security desk, we are strictly checked. Passports are looked at, mobile phones and cameras taken and visitor passes handed out. Once inside the visitor centre, people are more candid than some engineers had expected.
After coffee and cake, we are warmly welcomed by our host for this afternoon Mr Roy Veldhof who is Compliance Manager Safeguards at Urenco. He briefly tells something about the company and about producing enriched uranium by ultracentrifugation technology. Then the company film is started. Then suddenly the shuffling on the seats becomes noticeable; the engineers want to see something now. So Roy Veldhof and Arjan Bos, Head of Stable Isotopes, both take a group of engineers through the plant. Questions like "But how exactly does this ultracentrifuge work," and "How many of these centrifuges are set up here?," are answered as best they can. To the dismay of some engineers, not all questions were clearly answered. As Urenco has had to deal with corporate espionage before, certain information is now "classified". After being checked for radiation, we say goodbye at the visitor centre. Fortunately, none of the engineers contracted radiation, but there was considerable enrichment!
Text: Ir. Mariska van Cronenberg.
Description
The element uranium is the 92nd element in the Periodic Table of Elements. It was discovered in 1789 and owes its name to the planet Uranus, which was discovered eight years earlier. Uranium has 92 protons and 92 electrons. In nature, uranium occurs in the form of two "isotopes"'; namely U 238 and 235. That is, the isotope U 238 has 146 neutrons and U-235 has 143. The chemical properties of both isotopes are identical to each other.
The isotope U 235 is an important raw material for the production of nuclear fuel for nuclear energy. Natural uranium contains only 0.7% U-235. To serve as "nuclear fuel" in a nuclear reactor, the content of U-235 must be between 2 and 4%. Increasing the U-235 content from 0.7 to this required "nuclear energy quality" is called "enrichment". Because U-235 and U-238 have identical chemical properties and their physical properties differ very little, this enrichment is laborious.
At Urenco in Almelo, uranium is enriched to nuclear energy grade. This is done using ultracentrifuges. The uranium is delivered to Almelo in the form of uranium hexafluoride. Uranium hexafluoride, under reduced pressure, is a solid at room temperature. After heating to a maximum of 60 degrees Celsius, the solid uranium hexafluoride becomes a gas. This is then separated into its constituent uranium isotopes in the ultracentrifuge at a speed higher than 1 000 (!) rpm. The heavier U-238 is then hurled to the outside of the centrifuge and drained there. This leaves a higher concentration of U-235 in the centre of the centrifuge. This mixture is also tapped. Both "fractions" are each further processed in a subsequent centrifuge. The U-235 fraction is thus increasingly enriched and the U-238 fraction increasingly "depleted" of U-235. By switching very many ul-tracentrifuges one after another in a so-called "cascade", and thus centrifuging the gas repeatedly, the percentage of U-235 can be increased sufficiently to allow the uranium to be used for nuclear energy (concentration of U-235 2 to 4 per cent).
After an introduction and the company film, we will visit the enrichment plant itself.
PLEASE NOTE: Due to the security requirements in place at Urenco, we are required to provide Urenco with a list of participants containing each participant's personal data and identity card number prior to the excursion. So to be allowed to take part in this excursion, you must already state the number of your identity document and that of any guest you wish to invite when you register. During the visit, too, everyone must identify themselves with the same ID.
You must register before 13 April
Location
Urenco Nederland bv, Drienemansweg 1 , Almelo
Organiser
North Region
Name and contact details for information
Information from Anne-Marie Oudejans.