JAY-1 is a space nuclear reactor designed to deliver reliable, long-duration power for lunar and future space infrastructure. It is derived from Project LEUNR (Low Enriched Uranium Nuclear Reactor) is a compact, transportable micro-reactor concept that adapts the Canadian Nuclear Laboratories (CNL) SLOWPOKE-2 reactor design. This uses uses light water, low-enriched ceramic uranium dioxide (U0₂) fuel, beryllium reflectors, and passive safety cooling.