Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2012, Volume 15, Issue 1

Importance of Local Leak Rate in Determination of Gas Leak Localization in Enclosed Industrial Building

Abstract

Byproduct of electricity production by nuclear power plants, Tritium, is considered to be the main fuel source for fusion reactors. The tritiated water obtained in the fission reactors is transformed with the help of TRF’s in pure tritium gas. This is further used as primary source in the fuel cycle of the fusion reactors. The technical assembly of the TRF (Tritium Removal Facility) is regarded as a complex system of specialized equipment, sensors, detectors, valves and piping arrangements. Working pressure and temperatures of the TRF system defines the types of sensors, the vacuum technology and especially the possible operational safety issues. Leaks in the systems represent one of the main safety issues in a TRF. Environmental and work safety regulations state that if leak from a system, in a closed or open space, exceeds some threshold value it must be reported. Tritium has a special regulation because of its radioactive impact and it’s strategically importance.

                This article describes a calculation procedure that demonstrates that the leaks in the system could be localized and estimated. Using a least squares technique in a spreadsheet, parameters of a nonlinear equation can be determined for a localized leak in an enclosure, like a cold-box, e.g.. The calculations were based on a leak test using nitrogen and also industrial air. The pressure loss in the system was modelled by evaluating the leak through an orifice with specified open surface. This coefficient of opened surface was then used to calculate the loss of tritium in the system. The first step in the test was to fill the system. The pressure in the system was recorded as a function of time. This loss in pressure was described as proportional to the orifice coefficient.