We have a bunch of HELB doors around the local nuclear reactor site that I work at. Other than knowing they are to remain closed whenever possible, I never knew what HELB stood for. I read a site memo refering to them today so I now know that it is “High Energy Line Break”, but I don’t know what that is. I assume it is some kind of containment, but whether it contains a fire, building pressure, water or whatever I do not know.
Thanks
Looks to be ruptured steam lines:
http://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-notices/1996/in96064.html