According to the NRC notice, it's a JL Shepard Mark 168A https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2019/20190510en.html https://www.nrc

According to the NRC notice, it's a JL Shepard Mark 168A https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2019/20190510en.html https://www.nrc.gov/reading-rm/doc-collections/event-status/... There's some pictures of a similar device here: https://www.bnl.gov/nsrl/grsf/ https://www.bnl.gov/nsrl/grsf/ It doesn't show why you'd need a grinder to take it apart, though.