Investigation of the effect of nuclear fuel rods to the composition of the dissolved gas in the cooling water of the cooling
ponds of Paks Nuclear Power Plant is presented. Dissolved gases in coolant were measured for surveying the condition of the
nuclear fuel remained in service pool No. 1 of reactor unit No. 2 after its incident in April of 2003. Two different experimental
ways were applied in parallel for ensuring the better reliability of the results.