Yeah that's thermoelectric. They're talking about a full fat water cooled reactor here, with void coeffiency and temperature reactivity coefficiency and heat transfer coefficiency, moderator temperature coefficiencies, etc, etc. Its one hell of a lot more complex than a thermoelectric battery.

off-topic but i believe the abbreviation we use in Russian is superior. we call it RITEG (RadioIsotope ThermoElectric Generator), pronounced ree-tag