Fire prevention and protection in underground hydro power stations

This paper has been prepared by a task force of Working Group 06 of SC 23 to indicate some of the fire risks in an underground hydro power station, to describe some of the most commonly used fire extinguishing media and to describe some of the media' s advantages and disadvantages when used in different areas in the station. 
To get information for the statistics, a questionnaire has been distributed to utilities of underground hydro power stations and the results are collected in table 1-4. The data relate to underground hydro power stations built in the last 15 years.