CBRN event in Italy on Thu 22nd December 2011

On December 22nd 2011 Sogin S.p.A, which operates the former plant Fabbricazioni Nucleari of Bosco Marengo (AL) currently under decommissioning, communicated to ISPRA (Institute for Environmental Protection and Research)-which perform the functions of Nuclear Safety Authority- an anomalous event related to the decontamination machine by "shot blasting" located inside the plant occurred at 9:25 am local time. The machine is used to treat solid materials with very low contamination, resulting from the dismantling activities, in order to be cleared from the plant.
SOGIN stated that during the regular operation of the machine it was discovered that one of the bearing of the fans of the final filtration system had overheated. This resulted in the burning of the filtration unit with smoke being released into the room where the machine is located. Following this event emergency procedures were promptly activated and the fire squad intervened. The fire was put out following the emergency procedures. Plant management called the local Alessandria fire department in who confirmed that the fire was extinguished and the area was secure. At 9:55 am local time the emergency was declared to be over.
Based on the information requested by ISPRA and furnished by plant management, the results of the first measurements of radiation done by the Health Physics personnel of the plant excluded any contamination of the external area, and contamination of personnel and instruments used in the controlled area. The measures confirm, within the controlled area, the levels of surface and air contamination present before the event, as well as the levels of contamination of the filters on the chimneys of the plant measured before the event. Additional verification are in progress, including internal contamination of plant personnel.
From the beginning of the event ARPA Piemonte (The Regional Agency for the Protection of the Environment of Piedmont region), operating in continuous connection with ISPRA, intervened to monitor environmental radiation contamination. Data from ARPA Piemonte indicates that the concentration of alfa and beta total activity measured in atmospheric particle samples inside and outside the plant are comparable with environmental background values normally found.
Further investigations are in progress by the operator. ISPRA requested a detail report of the event, including corrected measures to be adopted in order to restart the machine operation. An inspection on the site has been also performed.