this our country and all its people could be in danger of nuclear attack in minutes by enemy missiles in hours by enemy aircraft our cities fire our factories prime target would be our air bases with all our aircraft on the ground our weapons of interception or retaliation not instantly available we might face another and infinitely more costly pearl harbor to avoid surprise disaster some of our aircraft must always be in the sky or on the alert carrying nuclear weapons these weapons are always on arm they will be armed only following the decision by the president of the united states only these ready aircraft with nuclear weapons can form our first  line deterrent force in peacetime our sure striking force in case of attack we the american people understand but we want to know the facts about one question doing live in danger of nuclear explosions and radioactive fallout if one of these airplane trips crashed or one of the nuclear weapons accidentally drop to give you the fact the united states air force present this bomber carries a nuclear weapon it is a well designed carefully maintained skillfully blown airplane but airplanes just like it have crashed and burned there was no nuclear explosion no radioactive fallout these are the facts the bomb but their watches over controls as safe as human ingenuity can make them to prevent accidental bomb really but nuclear weapons have been dropped inadvertently there was no nuclear explosion no radioactive fallout these are the back and specially instrumented aircraft verify the facts in the continuing nuclear safety program that test our nuclear weapons under controlled conditions that simulate every conceivable hazard vital to this nuclear safety program he is an air force special weapon setter at albuquerque new mexico here in ultra modern laboratory buildings work scientists in and out of uniform they work with the incredibly complex equations of nuclear physics which derived from einstein's famous relationship of mass to energy these cryptic figures programmed into lightning fast computers are the theoretical basis upon which these scientists together with those of the atomic energy commission can build nuclear weapons safety by research design development and laboratory test they ensure weapons not get built against accidental nuclear explosion they have been doing this successfully since one thousand nine hundred five in safety conferences with other defense department agencies and the atomic energy commission in thirteen years there have been a few accidents but not one has resulted in nuclear explosion or radioactive fallout these are the facts what keeps our nuclear weapon safe to understand why there has never been an accidental nuclear explosion you must first know how these explosions can be produced the general principles of nuclear explosion the explosion is the result of a very rapid release of a great amount of energy conventional explosions result from the rearrangement of whole atoms in some explosive material for the rearrangement of all atoms of hydrogen carbon nitrogen and oxygen produces explosive force on the other hand nuclear explosions result from the splitting of the nucleus of the atom is the basic principle of nuclear weapons all matter is composed of one or more of the one hundred elements the is the  plutonium and being most readily fission to cause nuclear explosion these elements are mildly radioactive they emit short range low penetration alpha particles while in the state they zap with particles do not have the harmful effects of the longer range and stronger gamma rays which are given off by a certain elements such as radium or by the products of nuclear fission  uranium and plutonium are among the heaviest heavy because the nucleus of the chatham contains large numbers of the fundamental particles called protons and neutrons when i'm free neutron hits this nucleus it splits into two parts early thing more neutrons which may go on to split the other nuclei the resulting fission products become highly radioactive emitting the long range and dangerous gamma rays the split nucleus weighs less than the whole one and this difference in weight is released in the form of energy nuclear energy after a fission harmful gamma radiation before fis innocuous alpha radiation to build up a nuclear energy release the fish in a moment cereal must be of a certain size shape or density then one of the neutrons escaping from a split atomic nucleus will in turn split another and a chain reaction is set up the masses now releasing nuclear energy but not quickly enough to cause a nuclear explosion this condition is called critical if the mass is now suddenly increased so that more neutrons are trapped each time an atomic nucleus is split a multiplier and chain reaction is maintained now the masses supercritical causing a nuclear explosion making the smaller mass critical if compressed still more a multiplying chain reaction sets in causing the mass to become super critical in a nuclear explosion no clear weapons make use of both of these  principles guns i've device can increase the mass of fissionable material to a super critical state instantaneously one some critical mass is propelled forcibly into another by an ordinary potter charge the increased mass becomes supercritical a multiplying chain reaction builds up until the nuclear explosion obviously if any mechanical device keeps these two subcritical masses apart the weapon is nuclear safety applications of this fact prevent accidental nuclear explosions in gun type weapons enclosed by a shell of ordinary explosive designed to direct its explosive force and word this effect is called implosion the detonators attached to the explosive are connected to a complex firing device which can fire every detonators simultaneously when all the explosive is detonated simultaneously the nuclear material is compressed into a super critical mass which results in a nuclear explosion type weapons or nuclear safety because only the specially designed firing device can produce the simultaneous detonation of all the ordinary explosive a deliberate effect possible only by the precise firing mechanism singled out and later be fired accidentally whether by malfunction crash impact or fire the explosive would not provide the all around the compression necessary for implosion instead it might push the nuclear material out of the shale break it into small pieces or even burn this on fission material emits only alpha particles because no nuclear explosion has taken place these awful particles do not penetrate the skin the simplest precautions can prevent their intake into the body and the simplest clean up measures can remove them so you see each type of nuclear weapon has its own safeguards against accidental nuclear explosions these are the facts and they are based upon practice as well as theory specially instrumented aircraft fly the tests that verify what happens inside a weapon what accident hazards the nuclear components may have to  nuclear safety is everybody's business although air force flies the test missions scientists and technicians from the atomic energy commission and other services man the test range and evaluate the findings of the elaborate instrumentation to measure the impact characteristics of various weapon types they are made without nuclear components so that this precious material is not waste they supplement the defamation tests that have been made with the complete nuclear weapons impact or shock does not cause nuclear explosion or radioactive  what has exploded is the ordinary explosive which is an essential part of nuclear weapons the ordinary explosive in a nuclear weapon can be a hazard exactly as in a conventional bomb depending upon the amount and location of the explosive and the speed and height of the drop we may experience of variety of ordinary explosions large ones small arms or none at all from the impact of the bomb to learn what temperatures and pressures would be created inside a weapon by an aircraft fire various types of bombs are subjected to a flame that of burning fuel because fire would also destroy the precious nuclear materials it is replaced by instruments their readings are compared with known characteristics of the fissionable material to assure that temperature is higher than any aircraft fire will not set off a nuclear explosion the characteristics quite plainly indicate that the ordinary explosives his burning in the weapon sometimes the explosives detonated because of close by and in ten se ds of such explosions are measured and compared with those connected to a nuclear weapon fire and ordinary explosives do not create the conditions necessary for a nuclear explosion these are the facts and on the vast desert ranges of the atomic energy commission the facts are verified by safety testing live prototypes of all new weapons before they go into production for our stockpile the tests are costly in money and manpower even more costly in the fis able materials on which our nuclear strength depends but they do provide insurance against nuclear accidents which make them a bargain at any price some take place deep in the earth fantastically complex instruments replace the five senses they record what happens when some of the explosive that surrounds the nuclear material of a new weapon is deliberately detonated they record only an ordinary explosive blast a random detonation has not created the implosion which would compress the nuclear material to a super critical there was no nuclear explosion no radioactive fallout each new design must be proved nuclear safety able to withstand accident fire or random explosive other tests with nuclear weapons are made above ground these are also designed to test the nuclear safety of new weapon types by intentionally detonating the explosive which surrounds the fissionable material sometimes these tests also provide data on the side effects to be expected if the fissionable material is broken up by the explosion air sample areas and test pads are used to gauge the area intensity and duration of the side effects in this way they learn not only what does not happen when the charge is deliberately fired but what does the explosive does break up the nuclear material and scatter parts of it over a small area this patient obama terril is mildly radioactive if the explosion or fire should suspend any of this material in dust or smoke it should not be inhaled or otherwise taken into the body in quantity that is why the trained monitoring and cleanup crews may wear respirators until air sample errors or alpha counters have determined that  no injurious concentration exist only a simple cleanup measures are necessary plus an effort to find and save the valuable material the findings from all tests set up to measure a possible radiological hazard are no external radioactive hazard from material on the ground slight radioactive hazard from prolonged inhalation of materials suspended in a small area near the accident but none from the start exposure is necessary for firefighting rescue or cleanup of the small area involved these are the facts facts that have dispelled the fears some myths about accidents involving nuclear weapons for anyone near an accident whether or not the crashed airplane carries a nuclear weapon here are the safe and simple rules stay away from the crash and i'm less you are needed for rescue bystanders endanger themselves and hamper others to be safe keep at least a quarter of a mile away from any burning airplane at this distance you are safe from the flames which may explode the jet fuel from detonating explosives and from flying debris these are the real dangers in rescue or fire but as they have almost been trained men who bear these responsibilities know how to do their job and get quickly away from all these hazards after the emergency is over the area is monitored for radioactive material and if necessary cleaned up by specially trained teams other specialists care for burned detonated pieces of ordinary explosives until this is done access to any crash area is controlled to prevent accidents and speed up the work the tests you have seen have proved the safety of our nuclear weapons program over and over again but the grim reality is the payoff i'll say it is a nuclear bomb are coming in for a crash landing not the impact of the crash landing nor the fire which often follows not even detonation of the ordinary explosive in the weapon because nuclear explosion or radioactive fall the safety that was designed during research bills and during development proved in the laboratory and on the range has withstood the ultimate tragic test these are facts they prove that you the american people can stay both safe and strong because the weapons your airforce must carry have been tested nuclear say the