Primo anniversario dell'incendio (DU) al CERN di Ginevra avvenuto il 26 gennaio 1999

[Proponiamo che tale data diventi da oggi una festività, la "Sagra Europea dell'Uranio Impoverito", con canti, danze, ricchi premi e cotillons...]

Alleghiamo, oltre alle indicazioni del CERN sull'uranio impoverito, il comunicato stampa sull'incendio occorsovi proprio un anno fa, il 26 gennaio 1999, cosa che dimostra che l'uranio impoverito è piroforico, ovvero tende ad incendiarsi a temperatura ambiente.

Anche al CERN, la realtà non è diversa.

Per cui, scusate se ancora insistiamo, non ci pare il caso di metterne centinaia di chilogrammi nelle ali e nella coda degli aerei. Civili o militari che siano. O in qualsiasi altro posto dove non si desiderino incendi: ospedali, cliniche, etc.

Il CERN è una struttura accreditata, una delle tante che ci forniscono informazioni puntuali che pazientemente in un anno abbiamo raccolto. Si tratta del Centro Europeo di Ricerca Nucleare situato a Ginevra e che ha a capo un italiano, Luciano Maiani.

Ecco cosa dice il CERN sull'uranio impoverito:

At 9.15 a.m. on 26 January a fire broke out when part of a particle detector was being dismantled. This apparatus comprised 80 plates of depleted uranium which is used for its strong particle absorption power. Depleted uranium is only very slightly radioactive. The work was being done by two people from a specialist company inside a sealed tent with an entrance lock. The tent itself was located in the large North Experimental Hall on the Prévessin site.

As the first plate was being removed some uranium dust fell onto the floor and spontaneously burst into flames. This is a phenomenon which can occur with fine particles of metal such as magnesium. The plates themselves cannot catch fire.

The two technicians immediately alerted the CERN Fire and Rescue Service, which arrived on the scene within five minutes. The fire, which remained confined within the closed area, was rapidly extinguished.

Once the fire had been put out, the measures implemented by CERN's Radiation Protection Group revealed that there had been no radioactive or chemical contamination outside the protected area. The two technicians doing the work had been wearing specialised protective clothing and equipment. They were not contaminated. The personnel present in the large North Hall have also been checked. The closed area where the dismantling work is taking place will be cleaned by a specialist company.

Uranium burns easily, a mixture of uranium dust and air may even ignite spontaneously.

No machining of uranium is allowed on the CERN sites. Order your uranium pieces via the TIS/RP Group and from a specialised firm. More information in Safety Note NS 7 ("Recommendations for the Safe Use of Uranium at CERN").

Note that all use of depleted uranium at CERN must be brought to the attention of the Uranium Controller and must be approved by the Director General. See Safety Code U 1, ("Procedure for the Control of Depleted Uranium").

Procedure for the control of Basic Nuclear Materials (BNM) on the CERN domain
...
Annex 3         MARKING OF BNM

When marking BNM at CERN, a number of aspects must be kept in mind:

  The marking of containers and equipment containing BNM is necessary for book-keeping purposes, since BNM must be distinguishable and kept apart from other materials. In addition, radioactive BNM must be marked as such and, in case of emergency, fire fighters need to know where radioactive BNM is stored or used.

  The marking of individual items (e.g. calorimeter plates) is not required and should even be avoided, as plates made from depleted uranium are often not surface-protected.

Taking depleted uranium (DU) as an example, the following rules shall apply:

   1.On arrival, all cases containing DU must be marked by RP with the sign "DEPLETED URANIUM" and a sticker "RADIOACTIVE".

   2.Calorimeters or any other equipment containing DU must also be marked with the appropriate signs.

   3.Areas where DU is present must be marked with the sign "RADIATION CONTROLLED AREA" or "RADIATION CONTAMINATION" according to the decision of the RP Section concerned. On this warning sign, the words "DEPLETED URANIUM" should be displayed.

   4.The signs may only be removed from any container or area after the last item containing DU has been removed and after cleaning and checking the container or area.

   5.Containers may only be released for general use after they have been decontaminated and checked, and after any indication that they were used for DU has been removed. Otherwise they must be treated as containing DU and must remain under surveillance.

N.B. This note does not describe the marking of containers containing BNM leaving the CERN site. The marking for this purpose follows the international transport regulations and is done exclusively by the RP Group.