Project Y's goal was to invent the first nukes.
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions , either fission -LRB- fission bomb -RRB- or a combination of fission and fusion -LRB- thermonuclear weapon -RRB- .. fission. nuclear fission. fission bomb. fission bomb. fusion. nuclear fusion. thermonuclear weapon. thermonuclear weapon. Both reactions release large quantities of energy from relatively small amounts of matter .. The first test of a fission -LRB- `` atomic '' -RRB- bomb released the same amount of energy as approximately 20,000 tonTNT .. fission. nuclear fission. first test. Trinity ( nuclear test ). test. Ivy Mike. The first thermonuclear -LRB- `` hydrogen '' -RRB- bomb test released the same amount of energy as approximately 10 e6tonTNT .. test. Ivy Mike. A thermonuclear weapon weighing little more than 2400 lb can produce an explosive force comparable to the detonation of more than 1.2 e6tonTNT .. thermonuclear weapon. thermonuclear weapon. A nuclear device no larger than traditional bombs can devastate an entire city by blast , fire , and radiation .. radiation. radiation. Nuclear weapons are weapons of mass destruction , and their use and control have been a major focus of international relations policy since their debut .. weapons of mass destruction. weapons of mass destruction. their use and control. Nuclear proliferation. international relations. international relations. Nuclear weapons have been used twice in war , both times by the United States against Japan near the end of World War II .. war. nuclear warfare. United States. United States and weapons of mass destruction. Japan. Japan. World War II. World War II. On August 6 , 1945 , the U.S. Army Air Forces detonated a uranium gun-type fission bomb nicknamed `` Little Boy '' over the Japanese city of Hiroshima ; three days later , on August 9 , the U.S. Army Air Forces detonated a plutonium implosion-type fission bomb codenamed `` Fat Man '' over the Japanese city of Nagasaki .. fission. nuclear fission. fission bomb. fission bomb. U.S. Army Air Forces. U.S. Army Air Forces. uranium. uranium. Hiroshima. Hiroshima. plutonium. plutonium. Fat Man. Fat Man. Nagasaki. Nagasaki. The bombings resulted in the deaths of approximately 200,000 civilians and military personnel from acute injuries sustained from the explosions .. civilians. civilians. military personnel. military personnel. The ethics of the bombings and their role in Japan 's surrender are subjects of debate .. Japan. Japan. debate. debate over the atomic bombings of Hiroshima and Nagasaki. Since the atomic bombings of Hiroshima and Nagasaki , nuclear weapons have been detonated over two thousand times for testing and demonstration .. Hiroshima. Hiroshima. Nagasaki. Nagasaki. atomic bombings of Hiroshima and Nagasaki. atomic bombings of Hiroshima and Nagasaki. testing. nuclear weapons testing. Only a few nations possess such weapons or are suspected of seeking them .. a few nations. list of states with nuclear weapons. The only countries known to have detonated nuclear weapons -- and acknowledge possessing them -- are -LRB- chronologically by date of first test -RRB- the United States , the Soviet Union -LRB- succeeded as a nuclear power by Russia -RRB- , the United Kingdom , France , the People 's Republic of China , India , Pakistan , and North Korea .. first test. Trinity ( nuclear test ). test. Ivy Mike. United States. United States and weapons of mass destruction. Soviet Union. Soviet Union. Russia. Russia and weapons of mass destruction. United Kingdom. United Kingdom and weapons of mass destruction. France. France and weapons of mass destruction. India. India and weapons of mass destruction. Pakistan. Pakistan and weapons of mass destruction. North Korea. North Korea and weapons of mass destruction. Israel is also believed to possess nuclear weapons , though , in a policy of deliberate ambiguity , it does not acknowledge having them .. Israel. Israel and weapons of mass destruction. policy of deliberate ambiguity. policy of deliberate ambiguity. Germany , Italy , Turkey , Belgium and the Netherlands are nuclear weapons sharing states .. Germany. Germany. Italy. Italy. Turkey. Turkey. Belgium. Belgium. Netherlands. Netherlands. nuclear weapons sharing. Nuclear sharing. South Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons .. South Africa. South Africa. independently developed. South Africa and weapons of mass destruction. renounced and dismantled. South Africa and weapons of mass destruction#Dismantling. The Treaty on the Non-Proliferation of Nuclear Weapons aims to reduce the spread of nuclear weapons , but its effectiveness has been questioned , and political tensions remained high in the 1970s and 1980s .. Treaty on the Non-Proliferation of Nuclear Weapons. Treaty on the Non-Proliferation of Nuclear Weapons. Modernisation of weapons continues to occur .