Nuclear reactors a mile underground promise safe, cheap power
Cost and feasibility of deep drilling
- Multiple comments cite oil/gas well data: mile-deep, ~1 m diameter holes are routine; rough costs range from a few million dollars for a bare borehole to maybe tens of millions with casings and multiple shafts.
- Relative to multi‑billion‑dollar nuclear plants, drilling is seen by many as a small fraction of total capex, though mining engineers stress “digging is not cheap” and projects routinely overrun.
Comparison with geothermal
- Many ask: if you can drill a mile down, why not just do geothermal?
- Counterpoints: useful geothermal gradients aren’t available everywhere; some geothermal schemes need numerous wells, cool off in decades, or induce earthquakes; nuclear offers much higher power density per well and works in geologically “boring” regions.
- Others argue that if deep drilling became cheap, advanced geothermal might still be preferable because it avoids radioactivity.
Safety, groundwater, and waste
- Proponents: placing the reactor below any water table in solid rock provides natural containment; meltdowns would be isolated far from the biosphere; spent fuel could be “disposed” by backfilling the hole, similar to deep borehole disposal concepts.
- Skeptics: “solid rock” and “below any water table” are seen as hand‑wavey; deep groundwater exists and migration paths are poorly understood; long‑term stewardship and bankrupt operators are unresolved issues.
- Some note that an underground accident is likely less socially and physically disruptive than a surface plant accident, but want rigorous hydrogeological analysis.
Thermal and engineering challenges
- Concerns about heat loss and friction in a mile‑long heat exchanger, and the pumping energy needed to lift coolant against a 160‑bar water column.
- Questions about how to service the reactor and manage mile‑long high‑pressure pipes if the unit is hoisted to the surface.
- Some suggest putting turbines or secondary loops underground, but that increases complexity.
Nuclear vs renewables context
- Large side discussion: many argue new nuclear is too expensive and inflexible compared to rapidly improving wind/solar plus storage, and that “base load” is an outdated concept.
- Others argue nuclear’s safety record per kWh is strong, fossil fuels are far deadlier, storage is not yet sufficient, and political/regulatory barriers—rather than physics—drive nuclear costs.
Public perception and politics
- Some see burying reactors as a clever way to address fears and simplify containment/disposal.
- Others think it reinforces the idea that nuclear is uniquely dangerous and won’t sway entrenched opposition.