Incident update at Gronau uranium enrichment facility


27 January 2010

As reported, there was an incident on Thursday 21.01.2010 at the URENCO uranium enrichment facility in Gronau, Germany, during which there was a minor release of uranium hexafluoride that was contained within the container preparation area.

Since the air in the container preparation room is filtered (hazardous incident ventilation), there was no release to the environment or to the local population. URENCO constantly monitors the radioactivity within the building and on site. In addition, control measurements were taken immediately after the accident.

The URENCO employee involved was transferred to the nuclear medical department of Dusseldorf University Clinic in Jülich on Monday, after having received first aid in Münster.

According to the doctors treating him, his general condition is very good.

The employee involved was exposed to only small traces of uranium and thus the radiological contamination is negligible. To demonstrate, the measure of contamination recorded at a maximum of 1.1 mSv, which equates to less than 5% of the legally annual permitted dose (20 mSv). The minor levels of uranium initially measured in his urine also significantly declined during the first day.

In addition, the small amount of contamination to the employee’s feet and legs was limited to the clothing. The minor contamination to the hands arose from contact with the clothing. The hands were, however, decontaminated on the spot immediately following the accident.

The nuclear inspectors, together with independent experts, investigated the incident on location in Gronau (on Monday 26 January 2010). As an interim report, the situation from a technical point of view is as follows:

Mass spectrometric analysis by URENCO shows that the uranium container concerned contained residual amounts of uranium hexafluoride, in contrast to the supplier’s declaration.

The investigation and analysis is presently continuing; conclusions are not to be expected before the end of this week.

During the course of the investigation URENCO will investigate what happened during the incident, plus the organisational processes involved, to establish far-reaching forward-looking improvements and to introduce measures for the avoidance of such incidents.

Explanatory information:

The container involved was a 30B container used for the transport of enriched uranium hexafluoride. These containers are used as multi-use containers and are in transit between the enricher and the fuel assembly manufacturer. The maximum fill quantity is 2.27 t UF6. The container is kept at negative pressure. Every five years a pressure test is carried out at 28 bar. In order to do this, the interior must first be cleaned. The container concerned had been delivered to URENCO as “clean and washed out”. Before the pressure test is carried out the containers are inspected in the container preparation area. This also involves an endoscopic inspection of the interior. The chemical release as described above occurred during the preparations for this test.

- Ends –


Jayne Hallett, Head of Group Communications, Direct Tel: +44 (0) 1628 402297, Email:

Howard Lee or Dudley White, Headland Consultancy, Direct Tel: +44 (0) 207 367 5225 or 5226, Email: or

The URENCO Group

URENCO is an independent international and technology group with its head office based in Marlow, UK. It operates plants in Germany, the Netherlands and the UK, and in the near future at a fourth site in New Mexico, US. It operates in a pivotal area of the nuclear fuel supply chain, which enables the sustainable generation of electricity for consumers around the world.

Utilising centrifuge technology, URENCO provides safe, cost-effective and reliable uranium enrichment services for civil power generation within a framework of high environmental, social and corporate responsibility standards. Currently URENCO fulfils around 25% of the global enrichment market, and the goal is to continue to build market share, with the aim of establishing URENCO as the leading global supplier of enrichment and enrichment technology.

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