The last power plant I worked on was Chinook generating station near Swift Current, a 350MW combined cycle plant for SaskPower. At $605M is was $75M under budget, you will never hear that on a nuclear project.

The various wind installations are typically fairly close to budget and schedule as well. Hydro is problematic, and that does show in cost overruns, because it is very difficult to predict the geotechnical situation for a given site until excavation starts. Given the stress on the structures, even small differences accumulate rapidly.

The worst thermal plant projects are consistently nuclear.

The refurbishment of Lepreau was supposed to cost $1.5B and take 18 months, it ended up taking $2.5B and just under 4 years to complete.

Flammanville-3 started construction in 2007 was supposed to be operational in 2012. They're now estimating it will complete commissioning in 2024. Costs have gone from €3.3B to €20B+.

Olkiluoto-3 started construction in 2005, was supposed to be operational in 2010, but only completed commissioning in 2022. Costs went from €3B to €11B, the not to exceed amount in the contract.

Hinkley Point C started about 2016, has been pushed back to 2028 and costs have gone from £16B to an estimated £32B.

Vogtle has been covered, but the V.C Summer plant was no better. Initial estimate was $9B, but the project was cancelled while under construction when the estimated total was projected to exceed $23B.

When you have a firm, that is ran by accountants - odds are, you have a firm that is great at squeezing on line items, but lacks the long term vision to see how that squeeze will lead to deficits and higher cost in the long term.

The fastest way to plummet a successful company, is to take the Industry experts out of the position (I mean people who worked their way up through the industry, and learned management along the way by experts btw), and replace them with an MBA/ Accountant who got hired into their upper management position without really working in the industry prior to.

And I pretty much guarantee you, this is what happened.