Leakage Through Steam Generator

Leakage Through Steam Generator Tubes or Tubesheet... 

An increase in radioactivity indicated by condenser air removal system monitors, and blowdown system monitors will reveal reactor coolant leakage through steam generators tubes to the secondary side. Routine analysis of steam generator secondary water samples will also indicate increasing leakage of reactor coolant into the secondary system. 

SRDC-6 and SRDC-7 are two essentially identical conditions involving water ingress through a moderate size leak in a steam generator tube. Core cooling is by conduction and as such the two conditions are the same as DBE-7. In DBE-7, however, the leakage is stopped after about 30 seconds such that only a small volume of water will enter the reactor vessel. As discussed in the... 

This alarm warns the operator that leakage through the steam generator isolation valve and check valve is occurring. Therefore, these sensors provide indication to the operator of the potential of steam binding of the EFW pumps. 

Mitigation of steam generator leakage problem The water heated in the reactor core passes through an integrated steam generator producing steam to drive the turbine. 

Steam generator leak detection Leakage of water into the sodium is monitored by leak detection systems in the sodium at the outlet of each SG, and in the pump cover gas. They are based on the diffusion of hydrogen through nickel membranes. Acoustic leak detectors are also provided for each SG. 

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