Studies on the solubility of hydrogen in molten Pb83Li17 eutectic alloy

• The hydrogen solubility in Pb83Li17 alloy is substantially low.
• The hydrogen solubility in the alloy mildly depends upon temperature.
• The activity of the lithium in the alloy is responsible for the reduced solubility.
• The melting point of the alloy increased with hydrogen concentration.
• Heat of fusion of the alloy mildly increased with hydrogen concentration.

Lead–lithium eutectic (Pb87Li17) alloy is a candidate material to be used as a secondary tritium breeder, neutron multiplier and heat transfer agent in the fusion reactor. The tritium thus produced in the alloy may be soluble or appear as a new phase of lithium-tritides and/or lead-tritides, which eventually affect the performance of Pb83Li17 eutectic. Therefore, solubility of tritium in the alloy at the operating conditions of the fusion reactor is a subject matter of investigation. Tritium being the isotope of hydrogen behaves more or less similar to the hydrogen. In the present investigation the solubility of hydrogen in the Pb83Li17 has been investigated as a function of temperature and pressure. It was found that, hydrogen solubility in the Pb87Li17 alloy is almost constant above 350 °C. Hydrogen solubility increases with increase of temperature up to 400 °C. Hydrogen solubility is 120 ppm at 400 °C and 800 Torr hydrogen pressure. The solubility decreases on further rise in temperature from 400 °C. However, at all the temperatures hydrogen solubility increased with increase of partial pressure of hydrogen.