Core Exit Thermocouples, Some Interesting history

This is an early document.  Click to view the entire page.  Core exit thermocouples have survived as a primary warning of core uncovering.  In the case of LOFT experiment L2-5, core exit thermocouples severely misled the plant operators.

And here is a the related analysis from Oak Ridge National Laboratory:

And, here is a detailed analysis by ORNL:
http://www.ornl.gov/info/reports/1982/3445605701648.pdf
Here is the cover page and one paragraph from page 81.  In general, the report supports HJTCs as monitors of inadequate core cooling.