Test and evaluation of the Navy half-watt RTG

In the autumn of 1975 the Navy took delivery of eight small-sized, plutonium-fueled radioisotope thermoelectric generators (RTGs) from four contractors (each contractor provided two RTGs). The purpose of these demonstration models is to prove conclusively that it is possible with state-of-the-art technology and materials to produce a super-battery with a 15-year life for use in the form of distributed power sources for remote undersea applications. It is easy to determine the RTG's beginning-of-life performance by actual measurements, but to forecast accurately its end-of-life performance requires rigorous determination of its reliability. This article discusses the test and evaluation program (TEP) used and the results obtained in determining that reliability. The TEP is divided into three general areas: mechanical-electrical, thermochemical-physical, and thermoelectric