To enhance the current lab capabilities, the lab has acquired a chemistry controlled recirculation loop (stainless steel 316, max. temperature 360ºC, max. pressure of 200 bar and volume flow rate 15 l/h), which will be connected to two autoclaves. A recirculation loop provides stable and controlled water chemistry for the entire testing duration in the autoclave. This recirculation loop consists of two parts: a low-pressure part for water regeneration and a high-pressure part for water pressurization, heating and cooling. The recirculation loop includes the following:
– A low-pressure part containing a 20L storage tank manufactured with stainless steel. The tank is equipped with degassing systems for nitrogen, hydrogen and N2/O2 mixture gases for reducing and maintaining required dissolved oxygen (DO) concentration. The DO level is controlled using a semi-automatic system that uses DO sensor reading as an input. A mixing pump will be used for mixing and circulating water through filter and water chemistry sensors. There is a chemical injection pump for feeding chemicals to water to test abnormal conditions (such as CRUD, high Li, and radiolysis effect on corrosion). Water chemistry sensors are installed in the low-pressure loop:
- A conductivity sensor to control the electrolyte purity.
- A dissolved oxygen meter to monitor the oxygen content in the electrolyte.
- An electrochemical dissolved hydrogen sensor and a corresponding measurement unit is used for on-line hydrogen monitoring.
The measured water chemistry parameters of both the outgoing and ingoing water flows can be continuously monitored.
– A high-pressure part equipped with a high temperature high pressure pump feeding water to the two autoclaves. The volume flow rate will be about 15 L/h which regenerates the autoclaves water volume up to three times in an hour. To ensure that the water entering the autoclaves is at the adequate temperature, two preheaters are installed in the loop while two heat exchangers are installed at the exit of the autoclaves.