NATO SPS Project 984595
"Protection of Underground Structures from Fuel Cloud Explosions"
Over the last two decades, a new family of explosive devices has been reported / applied, based on a combined incendiary and blast effects. This type of explosive device is known as thermobaric bomb. Device consists from container of fuel and two explosive charges. Detonation of the first charge opens the fuel container at a predetermined height and spreads the fuel in a cloud that mixes with atmospheric oxygen; the second charge detonates the cloud which creates an enormous blast wave. The period of time between the activation of first and second charges is minimum 125 msec. These are particularly effective in enclosed spaces such as tunnels, caves, bunkers and field fortifications. Fireball and shock wave can penetrate in underground structure, kill anyone sheltering deeper within the tunnel and destroy full infrastructure.
The risk from these types of devices is further increased by the lack of international controls and the potential that such devices could be obtained by terrorist organizations. International terrorism is a monumental threat to the national security of many countries, as clearly documented by the rise of daily terrorism incidents worldwide.
The Technical Manuals Unified Facilities Criteria and Antiterrorism Standards regarding the minimization of the effect of terrorist and accidental explosions do not consider the ways for protecting from thermobaric devices.
The goal of the project is to develop system for the protection of humans and infrastructure from thermobaric weapon. Development stages includes: a) determination of internal and external design parameters; b) elaboration of design and technological regalement for production; c) Production of prototype of working device; d) testing of device in underground tunnels (real-time conditions). The minimization of the blast effect can be achieved by ensuring the operation of the protective facility before the penetration of the fuel cloud in the tunnel. After activation, the protective system will create a liquid barrier (from dispersed water or mixture with other liquid and/or ultra disperse solid particles), which will exclude the possibility of extension of the aerosol (fuel cloud) in tunnel and simultaneously decrease up to minimum the detonation capability of the fuel could (due to the mixing with barrier liquid the fuel cloud composition will be changed).
The proposed Explosion Suppression System will be composed of:
i) Wireless device for the detection of explosions and activation of a protective system simultaneously with the explosion of the first charge;
ii) Absorber ensuring the discharge of dispersed water before the second detonator/charge explodes the fuel cloud.
The main tasks of the Project are as follows:
- Computer modeling of the potential impacts following a hazardous fluid release in underground structures
- Selection of the composition of damping/barrier agent and concentration of liquid phase according to the experimental results and validate by bench testing;
- Selection of hydraulic and structural parameters based on the results of the mathematic modelling and validate by experimental testing of the absorber;
- Development of a suppression system and fabrication of prototype;
- Testing of prototype in the tunnels (real conditions) and evaluation of protection effectiveness.
The work programme envisages the development of a quick and a highly reliable protective system based on experimental and analytical research, as well as prototype production, its testing and demonstration in the underground experimental base of the Mining Institute.
The Explosion Suppression System will be used for the protection of portal areas / entrances to critical infrastructure systems from the effect of thermobaric weapon. It can also be applied in petrochemical plants and other sites subject to the threat of fuel cloud explosion.