Interesting and disturbing. A quick google search shows the same plant had a leak of liquid nuclear waste from a holding tank. This happened April 16, 2016.
It was noted that this particular tank was failing since 2011. Following the 2016 incident the DOE’s reaction was ...
The U.S. Department of Energy released a statement Monday calling the leak an “anticipated” outcome of an ongoing effort to empty the tank in question. The Washington state Department of Ecology said, “There is no indication of waste leaking into the environment or risk to the public at this time.”
Hanford has several underground liquid waste storage tanks. They area all failing. They can’t just pump them out because they have no place to put that material. That is why they are building the Vitrification Plant that will turn this stuff to glass.