The article mentions that half-lives are such that it's not much of a problem even for "everyday steel" any more:
> But the days of low-background steel are coming to an end. Cobalt-60, the most common radioactive isotope found in our air from the nuclear blasts, has a half-life of around 5.3 years. Since the Partial Nuclear Test Ban Treaty in 1963, the atmosphere has become less, well, radioactive, meaning that increasingly the steel we make today – and hope to make in the future – is fit for our satellites after all.
> But the days of low-background steel are coming to an end. Cobalt-60, the most common radioactive isotope found in our air from the nuclear blasts, has a half-life of around 5.3 years. Since the Partial Nuclear Test Ban Treaty in 1963, the atmosphere has become less, well, radioactive, meaning that increasingly the steel we make today – and hope to make in the future – is fit for our satellites after all.