Large forgings & heavy components

Reactor pressure vessels (RPVs), steam generators, and primary-loop forgings are the slowest-moving link in the nuclear buildout. A 1,000+ MW PWR vessel is forged from steel ingots that can exceed 500 tonnes, and only a handful of presses on earth can pour them. The constraint is not steel — it is the forging press, the qualification pedigree, and the multi-year order slot. When the buildout accelerates, you cannot summon vessel capacity; you queue for it.

Who owns it

Globally, very-heavy forging capacity sits in Japan (Japan Steel Works), France (Framatome's Le Creusot), South Korea (Doosan), China, and Russia. JSW's Muroran plant runs presses up to 14,000 tonnes and has historically claimed roughly 80% of the world market for large nuclear forgings, and is described as the sole facility able to produce single-piece forgings for 1,600 MW-class vessels without welding. But the US-listed slice of this chokepoint is narrow. The cleanest exposure is BWXT, whose Cambridge, Ontario commercial-nuclear operations build heavy-walled pressure vessels and reactor components, and which won the contract to build the RPV for GE Hitachi's BWRX-300 at Darlington. Curtiss-Wright owns the adjacent primary-loop chokepoint — it is the sole qualified supplier of reactor coolant pumps to the Westinghouse AP1000 program, the largest canned-motor pumps it builds. Japan Steel Works reaches US investors only through a thin OTC ADR (JPSWY).

What breaks it

Demand is converging on capacity that takes years to add. The US administration has backed construction of ten new Westinghouse AP1000 reactors, with Poland and Bulgaria queued behind them. Each AP1000 needs an RPV, steam generators, and four reactor coolant pumps — Curtiss-Wright books roughly $110 million of RCP revenue per reactor over a five-year build. SMRs add a second wave: BWXT estimates ~$100 million per BWRX-300 vessel over ~four years. The bottleneck is that forging slots are long-lead and qualification (ASME N-stamp, NRC pedigree) is non-fungible. JSW is responding — in November 2025 it committed ~¥10 billion to lift generator-component and large-forging capacity ~1.5x by FY2028 — but that is a 2028 answer to a 2026 order book that is already running ahead of plan.

What forces the reprice

This chokepoint repricing is order-driven, not narrative-driven. The tape to watch is signed heavy-component contracts and final investment decisions, not MOUs. BWXT's April 2026 agreement to acquire Precision Components Group adds 500,000+ square feet of US heavy-manufacturing footprint (pressure vessels, heat exchangers, casks), closing in 2H 2026 — vertical integration into the exact constraint. Curtiss-Wright has guided that a major AP1000 RCP order is expected but excluded from 2026 guidance pending customer timing; conversion is the catalyst. Bulgaria's Kozloduy final investment decision, expected 2H 2026, and Poland's construction-license process are the dated unlocks for Western forging demand.

Be honest about size and earliness

This is real revenue, not a license option — but the nuclear slice is still small inside diversified industrials. BWXT's 2025 revenue was $3.2 billion, of which only $853 million was commercial operations (the majority is naval-reactor and government work), though commercial grew 63% and year-end backlog hit $7.3 billion — already up to ~$8.7 billion by the Q1 2026 print. Curtiss-Wright is a defense/industrial company where nuclear is a growth wedge, not the core — SMR revenue is targeted at only 12% of segment sales. Crucially, the marquee AP1000 vessel relationship — Westinghouse's December 2024 BWXT Canada MOU — is a memorandum, not a purchase order, and the headline ten-reactor US program is not yet contracted forgings. JSW reaches US wallets only via a thin ADR. Treat this chokepoint as structurally real and balance-sheet-backed at BWXT and CW, but size the nuclear-forging line as a minority of revenue today whose reprice depends on FIDs converting to steel. No investment advice; these are structural and catalyst observations.