A single 200 MW small modular nuclear reactor can simultaneously deliver roughly 90 MW of electricity, 0.6 kg/s of hydrogen (about 52 tonnes per day) and 612 m³/day of desalinated freshwater, according to a study published in Progress in Energy.

Fateme Dehghani and colleagues analysed an integrated system built around a small modular supercritical CO2 fast reactor. The design strings three functions together in a cascade. Reactor heat generates steam that drives turbines. A portion of that steam is diverted to High-Temperature Steam Electrolysis (HTSE), which splits water into hydrogen and oxygen. Because the steam arrives already hot, the process consumes less electricity than conventional electrolysis. The still-warm steam leaving hydrogen production then feeds a desalination plant.

The study, published in 2026 (Prog. Energy 8 035002), reports that reusing waste heat from hydrogen production to drive desalination lifts overall energy utilisation from 48% — electricity generation alone — to 53% in the full tri-generation configuration.

What does the cost analysis show?

The researchers modelled two operating modes. In a self-sufficient scenario, desalinated water is recycled internally to feed hydrogen production. In a market-led scenario, freshwater is sold externally.

The market-led option came out cheaper on hydrogen:

• Market-led mode: $2.93–3.19 per kg of hydrogen
• Self-sufficient mode: $3.49–3.88 per kg of hydrogen

The gap reflects revenue from water sales offsetting hydrogen production costs. Both ranges matter for portfolio planning: they sit near or below the levels that industrial hydrogen offtakers — steel, fertiliser and heavy transport — typically cite as competitiveness thresholds.

Why does the context matter?

Most hydrogen today comes from steam methane reforming of natural gas. The process is cheap but emits significant carbon dioxide. Water electrolysis avoids that footprint but demands both electricity and large volumes of feedwater — a constraint in exactly the water-stressed regions most interested in low-carbon industrial development.

The tri-generation architecture addresses both constraints at once. The reactor supplies carbon-free heat and power; the desalination stage turns seawater into feedwater and, optionally, a saleable product.

What should R&D managers watch?

The figures are modelled results, not measured plant data, and the study does not specify the assumed capital costs or discount rates behind the two cost scenarios. The 53% utilisation figure and the $2.93/kg floor are projections that depend on HTSE performance at scale, which remains commercially unproven.

Still, the numbers give development teams a concrete benchmark: one reactor module yielding three revenue streams, with hydrogen costs competitive with other low-carbon routes under the market-led configuration. The authors conclude that the system could offer an efficient and potentially attractive option for water-scarce regions seeking low-carbon energy and industrial hydrogen supplies — a proposition the next round of techno-economic work, and any pilot demonstration, will need to test against real engineering costs.