LABORATORI NAZIONALI DI LEGNARO
The presentation will concern the principles of architecture of some ventilation network and their piloting, during a eneralized fire, to compensate for excesses of pressure (or negative pressure) in areas. The achievement of the statutory and normative requirements regarding the confinement allows to answer the problems bound to the fire of areas containing of the hazardous material (radioactive in our presentation). However every installation has to be the object of a appropriate reflection according to the risks which it contains. The architecture of some network of the new ventilation has to answer the problems bound to the fire of areas containing hazardous materials. This architecture requires the implementation of fire sectors, of confinement sectors, to guarantee the not-scattering of hazardous materials in the outside environment. The standard ISO 17873 "Criteria for the design and operation of ventilation systems for nuclear installations other than nuclear reactors" describes fire sectors around which a confinement sector must be implemented. During a fire, the fire sector allows to retrieve airborne contamination during the rise in pressure, while maintaining the confinement sector at the negative pressure compared with the peripheral areas. Several solutions were studied to maintain the dynamic confinement system of the installations as long as possible without damaging the last level of filtration before rejection in the outside environment. This architecture leans on simulations, in established rate, executed by specific software for the study of the ventilation of the fire and the aero-contamination. In a context of fire risk of areas containing hazardous substances, this presentation will propose the solution of architecture of the ventilation network, answering at best the objectives of safety.

DATA: 07-05-2015