The Admiral indicated that Chief Pennington was a Reactor Operator. It is likely that he normally stood EWS but maintained proficiency on the RPCP - just like all the Chiefs I served with in RC Division on USS Michigan (Blue).
Dave, I have no argument with you on what Chief Pennington did or did not do. The man's achievement was exceptional. To go from being an steward in the segregated Navy, then as an E-6 Steward to an E-6 Electrician Mate, then to a nuclear qualified EMC is a statement of who he was and what he had to over come in his career. He survived a dark time in Naval history to serve in the most demanding of navy assignments.
Now back to the topic. Here is an article written in 1983 in memorial of him and the naming of a training facility after him. You will notice the reference to "Leading Chief Reactor Technician", which is the same as the in memory post of 1963 which you cite. So one can assume that the later article was in part based on the former.
During my time in the NUC program (1967-70), just four years after his death, I never heard of such a title, not that it did not exist, just that I never heard of it. The good chief's NEC was EM-3364-Submarine Nuclear Propulsion Plant Supervisor-Electrical.
If I may be so bold as to suggest that the title referenced in the articles may have been a misunderstanding, and does necessarily not mean Reactor Control.
Regardless of his actual assignment, he was an exceptional man.
Oh, by the way, after the loss of Thresher, all RPCs were altered to eliminate the automatic closing of steam stops on a reactor crash.
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