Nuclear tests & how they are carried out

What are nuclear tests and how are they conducted?

Nuclear tests help countries understand basic behaviours and characteristics of nuclear weapons. They provide information of how the weapons would perform under specific conditions. Given their enormous destructive powers and psychological advantage they confer, countries have often used nuclear testing to send a signal to friends as well as adversaries. A nuclear test is often seen as an indicator of scientific and military prowess.

The tests are only conducted underground. Atmospheric testing was banned through the 1963 Partial Test Ban Treaty though some countries such as France continued to do them till 1974.

What are nuclear weapons?

It’s a weapon which derives its catastrophic energy from nuclear reactions either by fission or by fusion. In fission weapons, a mass of fissile material like enriched uranium or plutonium is assembled into a supercritical mass that starts an exponentially growing nuclear chain reaction. Weapons in this type are known as atomic bombs, A-bombs or The Bomb.

The other one produces a large amount of energy through nuclear fusion reactions and can be over a thousand times more powerful than fission bombs. These are known as hydrogen bombs, H-bombs, thermonuclear bombs, or fusion bombs.

How many nations possess nuclear weapons?

Officially only eight: United States, Russia, United Kingdom, China, France, India, Pakistan and North Korea. Of these only first five are recognised nuclear powers. Unofficially, Israel and South Africa too are suspected of having the technology. There is another category of nations which is carrying out clandestine nuclear programs. Iran and Saudi Arabia are believed to be doing so.

Which country conducted the first test and how many countries so far have carried out such experiments?


The first atomic test was detonated by the United States on July 16, ’45 during the Manhattan Project with the code name ‘Trinity’. The test was originally to confirm the feasibility of nuclear weapon which was later used against Japan. And as far as tests are concerned the US tops the list with 1,054 tests by official count, followed by Soviet Union with 715 tests, France 210, UK 45, China 45, India 5, Pakistan 3 and North Korea 1.

What have been the efforts to curb nuclear technology?

Ever since the devastation of Nagasaki and Hiroshima shook the world in ’45 — that ended World War II — there has been a demand to curb the proliferation of nuclear technology. The opponents of the nuclear weapons were lobbying hard to create some kind of platform that will check and monitor nuclear powers. First notable success to these efforts was recorded in ’63 when partial tests ban treaty was designed.

The treaty permitted underground tests but France continued atmospheric testing until ’74 while China carried on its programme till ’80. So as name suggest it bore a partial success since countries like France and China refused to sign the treaty.

Then around five years later in ’68 came the Nuclear Non-proliferation Treaty, better known as NPT. This one prohibited all non-nuclear weapon states “possessing, manufacturing or acquiring nuclear weapons or other nuclear explosive devices”. All signatories, including nuclear weapon states, committed to the goal of total nuclear disarmament.

Though 188 countries signed the treaty, two — India and Pakistan — out of eight confirmed nuclear powers and one unconfirmed nuclear power Israel, neither signed nor ratified the treaty. Later, North Korea too withdrew from the treaty.

Why was the NPT controversial?

The answer lies in an exclusivity of the technology. The NPT allowed only five states to own nuclear weapons. They are France, China, Soviet Union (now Russia), the UK and the US. Incidentally, members of this Club of Five are permanent members of the United Nations.

The “Big Brother” attitude of these states triggered a kind of resentment amongst the rest. Three countries India, Pakistan, and Israel declined to sign the treaty. South Africa signed it but not before it carried out its own tests.

These countries-tries argued that the NPT creates a club of “nuclear haves” by restricting the legal possession of nuclear weapons to “have not” states. The treaty never explained on what ethical grounds such division was valid. This resulted in the NPT having a limited appeal.

What is the Comprehensive Test Ban Treaty?

Considering a restricted success of the NPT efforts were on since ’93 to have a comprehensive agreement that will take care of all aspects of nuclear technology. Intensive efforts were made over the next three years to draft the Treaty text and its two annexes, culminating in the adoption of the Comprehensive Nuclear Test Ban Treaty (CTBT) on September 10, ’96 by the United Nations.

The Treaty was opened for signature in New York on September 24, ’96, when some 71 nations, including five of the eight then nuclear-capable states, signed. As of now the CTBT has been signed by 176 countries and ratified by 135.

But India, Pakistan and North Korea rejected it blaming US, which has signed the CTBT but not ratified it. This created further division since anti-US lobbies wanted to set up comprehensive, all pervasive mechanism to monitor nuclear power states.
Negotiations on this are still on....!