What did Three Mile Island Units 1 and 2 cost to build?
Three Mile Island is a two-unit nuclear generating station on the Susquehanna River near Harrisburg, Pennsylvania. It is best known for the 1979 partial meltdown in Unit 2, the most serious accident in US commercial nuclear-power history.
Final project cost
$1.1 billion
Cost basis: 1978
The short answer
$1.1 billion
The US Energy Information Administration source reports an original construction cost of $1.557 billion for both units, expressed in 2007 dollars. That defined two-unit figure is the answer used here.
Cost evidence
Basis of the published figure
What the number includes
Cost scope
The amount covers the original construction of both generating units. It does not represent the later clean-up cost of the Unit 2 accident, subsequent operating expenses or a current estimate to build an equivalent plant.
Project record
Timeline
Project context
About Three Mile Island Nuclear Generating Station
Construction began in 1968 and the second unit entered commercial operation in December 1978. Together the units had a recorded generating capacity of 1,839 megawatts before the accident permanently changed the site's operating history.
Reading the data
How to interpret the figure
The cited figure is already expressed in 2007 US dollars. Clueterra preserves that stated basis and does not apply a foreign-exchange conversion or update it to 2026 dollars.