Why would the heads of the Manhattan Project have been imprisoned in the event of its failure?

Question

In The Making of the Atomic Bomb by Richard Rhodes, Secretary of War Henry Stimson is quoted as saying, after the Trinity test and Potsdam declaration but before the bombing of Hiroshima:

I have been responsible for spending two billions of dollars on this atomic venture. Now that it is successful I shall not be sent to prison in Fort Leavenworth.

It is also indicated in the text that project director Leslie Groves would have been in trouble:

The bomb was also to be used to pay for itself, to justify to Congress the investment of $2 billion, to keep Groves and Stimson out of Leavenworth prison.

For what crimes would they have been charged? Or would they simply have been detained until the end of the war? What precedent had Stimson worried about the possibility of being imprisoned for being the leader of a failed project?

Answer 1

It is a mere reflection of the lingering doubts still retained by these non-scientific personnel about the veracity of the science; that somehow the scientists had pulled a fast one on everybody and it was all a big joke. If that had happened there would no doubt have been charges of fraud, and possibly treason.

No scientist working on the project had the least doubt about the science, as witness the memoirs of Richard Feynman: Surely You're Joking Mr. Feynman

Note that scaling by the Consumer Price Index values for 2014 (700) and 1945(54) converts that $2B (1945 $) into roughly $26B (2014 $).

Answer 2

It was a figure of speech.

What Stimson was saying that if the Manhattan Project had been a $2 billion "dud," most people would have considered that "criminal."

And looking for scapegoats to blame, such as himself and General Groves. "Incarceration" was probably putting too strongly, but they would likely have been "pilloried" by public opinion.