Underground chambers

Underground chambers are also constructed in frozen earth (see subsection Xow-Temperature and Cryogenic Storage ). Underground tunnel or tank storage is often the most practical way of storing hazardous or radioactive materials. A cover of 30 m (100 ft) of rock or dense earth can exert a pressure of about 690 kPa (100 Ibf in"). 

A permit-to-work system is essential to control entry into confined spaces, e.g. tanks, reactors or underground chambers. Requirements... 

For thirteen generations Pulipani s descendants have watched over that stone slab that marks the gateway to the underground chamber. Long ago, Bhogar s little shrine was set atop that hallowed spot, and even today, is still worshipped by the vigilant sons of the faithful Pulipani. 

The proceedings of these various inquiries were noted and put on file, but the mood of the time was not favourable to military expenditure on the grand scale. An incomplete list of potentially useful caverns and underground chambers was compiled, seemingly with little enthusiasm, but no further action was taken and the scheme was allowed to languish for nearly a decade. 

DISPOSAL AND STORAGE METHODS may be subjected to ultimate disposal by controlled incineration may be stored in liquefied form under its vapor pressure at normal atmospheric temperatures both above and below ground refrigerated liquid storage at atmospheric pressure may be used systems are closed and insulated, and the liquid petroleum gas vapor serves as the refrigerant for the system as it is circulated through pumps and compressors may also be stored in pits in the earth capped by metal domes, and in underground chambers. 

Plastics are also now used as a replacement for concrete in underground chambers. The performance of chambers is much less critical than that of pipes since they are not under pressure and can be readily replaced when necessary. Increasingly, recycled polyolefins are being used in this kind of application, which is a particularly appropriate second use for mixed thermoplastic polymers that are not exposed to UV light (Chapter 4, page 86). 

On November 2, 1992, a detonation with an approximate energy of 225 tons of TNT occurred in a Swiss underground installation for the storage of old ammunition and explosives prior to their final destruction. Six people were killed and the installation was completely destroyed. The rock cover above the underground chamber broke off and rock as well as concrete pieces were thrown over a wide range of the surrounding area. 

An underground chamber requires inspection and possible repair. A risk assessment has identified the possibility of the presence of methane within the chamber. 

A root cellar is an underground chamber used to store fhiits, vegetables, and even meats. In extreme cold, farmers put large vats of water into the root cellar to prevent the fhiits and vegetables from freezing. Explain why this works. 

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