Dounreay coolant to go

1 October 2003

NNC is developing a system to remove a sodium­potassium alloy used as a coolant at the Dounreay fast breeder reactor. One option is to drain the water- and air-sensitive NaK alloy from the reactor system and deal with the residues using NNC's water vapour nitrogen (WVN) process.

After draining, the remaining coolant coats all the exposed steel surfaces within the system and forms small pools. It must be removed and converted to hydroxide, which can then be flushed out with water, without generating excess hydrogen.

NNC's WVN process passes low-concentration water vapour carried by nitrogen over contaminated surfaces. The rate of hydrogen production, which indicates how much contaminant remains, is measured using two Systech 542 programmable gas analysers.

The process is being run at test scale at NNC's Warrington site to determine operational parameters and carry out other tests before the process is scaled up.




Privacy Policy
We have updated our privacy policy. In the latest update it explains what cookies are and how we use them on our site. To learn more about cookies and their benefits, please view our privacy policy. Please be aware that parts of this site will not function correctly if you disable cookies. By continuing to use this site, you consent to our use of cookies in accordance with our privacy policy unless you have disabled them.