Oppenheimer is starting to show some of the immense stress that he is under. He's chain-smoking four or five packs a day; he has awful coughing fits; and he's really, really skinny.
However, as his body seems to get weaker, he also starts to exude a seemingly limitless energy that allows him to oversee just about every aspect of the Manhattan project. This is especially impressive, as people are pretty much working around the clock six days a week (Oppie insists that people unwind on Sundays).
Oppenheimer calls Feynman into his office. Feynman assumes it's because he's in trouble…again. After all, not only does his family write to him in code for fun, which ticks off the Army censors, but he's also been breaking into the Tech Area and removing top-secret documents whenever he wants to read them.
He's actually been summoned because Oppenheimer has a really important job for Feynman to do.
Los Alamos is just a small part of the Manhattan Project. There's a whole secret city of eighty thousand workers in Oak Ridge, Tennessee who are preparing the uranium for the bomb. But because everything is so top-secret, no one at Oak Ridge knows how to handle uranium safely. (Yeah, that seems highly problematic to us, too…)
Oppie wants Feynman to go to Oak Ridge, inspect the facility, and train the workers in order to prevent a nuclear accident. Whatever you say, boss.
The factory at Oak Ridge is a disaster waiting to happen. Luckily, Feynman is able to help the workers learn how to separate U-238 atoms (normal uranium) from U-235 atoms (the ones that will fission) safely and send them off to Los Alamos without blowing themselves to Kingdom Come.
It's a slow process, though. If everything goes well, they will have enough U-235 to make one atomic bomb by the end of the summer of 1945.
Groves is frustrated by how slowly their nuclear arsenal will be able to grow. Luckily, during the course of their studies scientists have discovered that U-238 atoms become plutonium when they're bombarded with flying neutrons and absorb them—and plutonium atoms fission even faster than U-235 atoms.
Groves creates a plant in Hanford, Washington in order to produce plutonium as quickly as possible for more atomic bombs.
Even with all of these plants, hundreds of thousands of employees, and millions of dollars being spent, Congress is still in the dark about what's going on, thanks to Roosevelt keeping it super-duper top-secret.
A Missouri senator by the name of Harry Truman (perhaps you've heard of him) gets curious about these mysterious war plants and sends investigators to Oak Ridge and Hanford.
Truman quickly gets a visit from Secretary of War Henry Stimson, who calmly informs him that it's in his best interest to let sleeping dogs lie.
Truman can't help himself, though, and continues to be a pest, poking around for information.