Risk prediction problems of chemical hazards in the transport of dangerous goods by motor transport

O.N. Savchuk; A.A. Aksenov.

Saint-Petersburg university of State fire service of EMERCOM of Russia

The article discusses the features of the software implementation on a computer risk assessment chemical hazards of accidents of vehicles carrying hazardous chemicals, ways to improve operational risk assessment of chemical hazards such accidents and recommendations for ensuring the safe transport of hazardous chemicals by road transport within settlements, as well as the elimination of consequences of accidents.

Keywords: movable chemically dangerous objects, dangerous chemical substance, risk of chemical hazards

Every year a large number of hazardous chemicals are transported by road, routes which were forced to pass in the settlements. Growing risk of large masses of people in the destruction of such facilities as a result of terrorist acts[1].

When transporting poisonous substances by road accidents, the following scenarios:

- сrash while loading poisonous substances;

- accident directly during transportation;

- accident at discharge poisonous substances.

Most noteworthy accident when transporting dangerous chemical substance distance, as the substance of loading / unloading areas provided security at a high level. What places are at a considerable distance from residential areas, there are technical means of preventing accidents and in case of its occurrence is possible fast liquidation of accidental release of hazardous substances. What can not be achieved during transportation.

Feature of prediction of consequences of depressurization on objects such will be: nature of flood of a liquid phase of dangerous chemical substance when driving depending on the area of a hole, the number of the punched capacities and existence in them of dangerous chemical substance, speed of movement of transport, character of the spreading district, the accounting of meteoconditions.

Proceeding from features of prediction of accidents on the relative frame objects with dangerous chemical substance, it is possible to allocate the following problems:

- adequately the meteocondition in an accident emergence point is not considered;

- depressurization of automobile tanks with the subsequent inflaming of dangerous chemical substance when blasting in case of acts of terrorism is not considered;

- conditions of penetration of dangerous chemical substance into the spreading surface are not considered;

- conditions of distribution of a cloud of dangerous chemical substance taking into account building and a land relief are not considered;

- there are difficulties in expeditious definition of input datas for calculations of depths of zones of possible chemical infection.

Calculated depth of a zone of infection Г_расч is defined:

Г_общ =Г^'+0,5Г"

Г_расч = min (1.1)

Г_пер=V_п

where Г_общ – the common depth of a zone of infection caused by influence of primary and secondary cloud, ; Г^' – the greatest and Г" – the least value from sizes of depth of primary and secondary cloud of dangerous chemical substance; Г_пер – extremely possible value of depth of transfer of a cloud; V_п – transport rate of the forward front of a cloud at data of speed of wind and degree of vertical stability of air.

For the solution of the designated problems there is a need for development of a new technique of an assessment of risk of chemical danger when transporting AHOV by the motor transport.