The nuclear fleet and the fuel switch

Ukraine operates a fleet of pressurised water reactors of Soviet design, and they produce a very large share of national electricity — in most years more than half. That makes the fleet the backbone of the system, and it makes everything about its supply chain strategically important.

Why fuel supply was the vulnerability

Nuclear fuel is not a commodity. Each assembly is engineered for a specific reactor design, licensed by the regulator for that reactor, and validated through years of operating experience. For a long time there was one supplier for this reactor type, in one country, and that supplier could set terms.

Diversification therefore was not a procurement exercise. It required a second manufacturer to design a compatible assembly, the regulator to license it, and the operator to load it in stages and prove it performed as predicted, over years of monitored operation.

How it was done

Slowly and carefully, which is the only way. Test assemblies first, in a single reactor, under close observation. Then partial cores. Then full cores at more units as the operating record accumulated. Fifteen years from the first trials to a fleet where alternative fuel is normal.

By the time it mattered most, the capability existed. That is what a strategic decision looks like in practice: unglamorous, technical, expensive at the time, and decisive much later.

The lesson beyond nuclear

Every business I run has a version of this problem — a critical input with a single supplier, where switching requires qualification, testing and time. The temptation is always to defer it, because the current supplier is working and qualification costs money now for a benefit that is hypothetical.

Ukraine did not defer it. I have used that example in my own board discussions more than once.

Single-source supply is the cheapest option while everything works and the only option on the day it does not. In the distribution years I met this repeatedly at a small scale: a spare part with no second source is the weakest link in your contract, and it is not a link you can replace during a crisis. What Ukraine did with reactor fuel was the same lesson applied at state scale, and applied while there was still time.