1933, but it took until 1945 to build them.
1945
Nope.
He invented the first nuclear weapon, the atomic bomb.
The meaning of the word nuclear weapon, is a weapon that has a nuclear warhead on it.
nuclear energy was first invented for a weapon of mass destruction (WOMD) but it was later developed as a main ingredient in the narcotic known as Molly (MDMA)
This nuclear weapon is called an atomic bomb or a nuclear bomb
Nuclear weapon detonations
If by "bomb" you mean a conventional explosive weapon, then the nuclear weapon is more powerful.
Nuclear winters imply that a nuclear weapon was used. In 1817, none was even invented. The US used the first against Japan at the end of WWII in 1945.
A hydrogen bomb is, by far, the most destructive weapon that mankind has ever invented. It is the most powerful type of nuclear bomb.
nuclear chemicals such as plutonium
No. LLNL even tested several Uranium-Hydride bombs in the 1950s. Even though their computer models said the devices should explode, none gave a nuclear yield. One could use the waste from the reactor as a Radiological Weapon, but the reactor itself is not useful as a weapon.