CANDLES used $^{48}$Ca for the search of neutrinoless double beta decay (0v$\beta\beta$). However, a large amount of $^{48}$Ca is required to sense this ultra-rare event. Laser isotope separation (LIS) provides feasibility for separating the target isotope by selectively exciting the target isotope with a high-power and single-frequency laser. The new design of the irradiation unit was introduced, and the first step is to achieve a stable production system from one of the six atomic beam generators by 2W laser power at 422.792 nm oscillation wavelength. The proper design of the upscale production system was developed, including a stable atomic beam generator, power scalability of the laser system, a collection system, and a monitor and control system. The first milestone is achieving 2 mol/year production rate.