While Congress considers proposals to funnel billions in loan guarantees for the construction of new nuclear reactors, the costs of pending projects continue to sky-rocket. This week CPS Energy released updated cost projections for two nuclear reactors proposed at their South Texas Project. CPS is partnering with NRG Energy and Toshiba on the project.

CPS estimates that the project’s Advanced Boiling Water Reactors will now cost $17 Billion—more than 3 times higher than initial projections of $5.4 billion.

The Department of Energy currently has $ 18.5 billion in loan guarantees available for nuclear reactors.  A current Senate proposal, known as the Clean Energy Deployment Administration , could massively expand this number to more than $100 Billion.

Taxpayers could easily be left holding the bag if federal loan guarantees move forward on these risky projects.  This latest cost explosion at the South Texas Project further demonstrates nuclear reactors are extremely costly and unpredictable.  The Congressional Budget Office has estimated a 50% default rate for nuclear projects, and in light of this recent news the prospects for new reactors could be even more bleak.  Hedging taxpayer-backed bets on their completion is not the way forward on the nation’s energy concerns.