Pay special attention to the word "largely" and "unknown" in the article quote. This is a current article talking about a nuclear accident that happened over 8 years ago.
Quote:
ARTICLE QUOTE: "Robotic probes have photographed and detected traces of damaged nuclear fuel in the three reactors that had meltdowns, but the exact location and other details of the melted fuel are largely unknown."
Link to full article:
https://www.latimes.com/world/la-fg-fukushima-nuclear-fuel-removal-20190415-story.html