[en] The Nuclear Test Gage (NTG) at the Savannah River Plant is a subcritical multiplying facility (low k) with H₂O moderator and 2.54-cm-diameter fuel slugs of 5 wt percent ²³⁵U in aluminum alloy at a 4.285-cm triangular pitch. The core of the facility is 61-cm long with a normal diameter of 27 cm. The NTG is used for quality control of reactor components, such as ²³⁵U-Al fuel tubes, Li--Al target tubes, control and safety rods, and miscellaneous special irradiation elements. A component is tested by passing it through an axial test port 11.63 cm in diameter. The ion chamber response from the resultant change in neutron source multiplication is then compared with corresponding responses from known standards