More on UHI (Upper Head Injection) Ultra High Risk

Of course, this is history. UHI has been out of the picture for some time.

You may look at my earlier entry of today. This is part of a very long package that I'll stitch together from this entry and much more to come. The first slide is a repeat from my earlier entry today. It is followed by slides that illustrate that years later, that reasoning is followed, namely that since UHI is not needed to handle a LOCA, the presence of UHI may be ignored in PRA's. In other words, you could store tons of explosives at a power reactor site and that would be OK because it is not needed to deal with a reactor accident.

I wrote my warning in October, 1994. The PRA for Sequoyah is dated January 1991. The last slide is copied from the Japan Atomic Industrial Forum (1990) and reveals plans to get rid of UHI at the two Ohi units. So, here are the slides. Click on the slide to enlarge and then click on the back arrow to get to the next slide.

The above EPRI memo of October 1994, implies that it is reasonable to ignore the presence of UHI in the McGuire PRA.

The above identifies the Sequoyah PRA dated January 1991, over five years later than the EPRI memo.


The above has a line that states UHI is not considered in this PRA. It thus copies the McGuire PRA.

The above has a paragraph that presents the weak argument for not including UHI in the PRA.

The above, November 1990, discusses the first steps to get rid of UHI at Ohi Units 1 and 2.