That's not a subsidy. It's a claim by a third party (who, coincidentally, exists to advocate for strict regulation of the nuclear industry) that the government is underestimating the risk associated with nuclear power. Differences of opinion regarding actuarial tables aren't subsidies.
The wiki article claims that CATO also supports this, but that claim does not appear to be supported in the cited material.
The wiki article claims that CATO also supports this, but that claim does not appear to be supported in the cited material.