Always/Never: The Quest for Safety, Control, and Survivability - Part 2

nuclear detonation safety began with the first two atomic bombs in the summer of 1945 the days of fat man and little boy on Tinian Northfield there were four great parallel runways they've ran nearly across the total width of the island at that point often times or accidents such that you could see burning b-29s and in the vicinity of the runways the little boy and the Nagasaki were not safe if we'd had an accident if it dropped them Murph we'd crashed on takeoff from woman on Kenyon we would we're here to wiped out part of the 20th air fourth we had lost 400 b-29s a lot of people they were not safe well then I guess actually bomb which was an implosion bomb was built up by hand in the plutonium core was inside to high explosive the bomb contained enough plutonium in a sufficiently close to being critical all by itself that there probably would have been some nuclear yield little boy the enriched uranium gun-type device and fat man the more complex plutonium implosion system posed serious nuclear safety challenges but one of the problems of course was to make weapons safe in the only way we could do was keep the fissile material separate from the assembly mechanism now we didn't do that for Nagasaki we just took off and hope everything would be all right both bombs were fully loaded with fissile material at takeoff nuclear safety consisted of a system of green and red plugs the principal safety measure in a loaded bomb a bomb that was aboard the aircraft was the was electrical safety the plugs essentially kept the circuits open from the power supply to the high explosive and its detonators in flight before the bomber was pressurized to at 8,000 feet we took out green plugs and install red books and with the arming plugs in that connection was made so there was that physical action that had to be taken aboard the aircraft before the bomb was released war time 1945 drove many hard decisions including the first use of two atomic bombs on Japan one untested and both unsafe in an accident from 1947 on to 1950 the mark 3 bomb was the primary operational weapon and this was a militarized version of a fat man it wasn't a bomb it was a collection of parts that had to be assembled by a specially trained team and so all the problems that existed with the weapon delivery were Negus a key also existed through the mark 3 meaning it some accident happened to it you would have a nuclear yield so mother design criteria for the mark 4 and all later weapon was that the new per capsule would be separate the mark 4 was the first weapon to include a function we call in-flight insertion which meant that the nuclear material in the form of the capsule could be moved along a track and put into the center of the weapon while it was on the way to the target the next stage was instead of doing that manually was to build within the weapon itself a mechanism that would have the capsule external to the explosive so Sandia developed in flight insertion mechanism which the pilot could turn on a switch and the mechanism would insert the capsule inside of the high explosive assembly the back end of the capsule of course had that piece of high explosive which made up the totality of the sphere the initial generation of nuclear weapons were capsule type weapons a separable nuclear capsule served the interests of absolute nuclear safety and for a short time it also provided the means of civilian control and in the very early days civilian control of nuclear weapons meant civilian custody and when they had an exercise the sirens would go off and the gate between the two fields so to speak with the military on one side and the Atomic Energy and they just sound maternal on the other side gate would be open and there would be a transfer of material with receipts being signed over time though that arrangement proved unworkable the military argued that in a crisis this would delay a nuclear response when ours might matter in 1950 this problem came to a head the United Nations sent an army to Korea under a single command the horizontally Truman was petitioned by the air force of first the bombs and later the capsules for potential use in the Korean conflict as the war in Korea escalated and threatened to develop into a global conflict President Truman approved the transfer of nuclear components to the US Air Force based in Britain from the perspective of the airforce they did not enjoy the notion of not being allowed to deliver a nuclear weapon in time of war without the approval of this upstart civilian agency the idea that nuclear weapons were actually going to be part of integrated into American security created a tremendous tension between this idea of civilian control and the ability to military to plan for nuclear strikes withholding authority from the military was ludicrous to a commander like Curtis the name there was tremendous pressure on the nuclear command and control system to shift from an never oriented system to something that would be better able to respond in a crisis and from that time on the military had custody of nuclear weapons there was this bromius if i may use that expression about nuclear weapons it meant that the services if they were to be relevant which means getting funding from the administration and the Congress had to be part of the charm circle of nuclear capabilities so the Army strove to acquire nuclear weapons the Navy in order to demonstrate its relevance in the period equipped as carriers was nuclear weapons and of course the air force during that period was central to the build-up so every offensive capability they had had to become nuclear everyone had to have one now what happened in the early 50s a specter of guided missiles severed the picture and getting the missile to the target was a Department of Defense responsibility Department of Defense for missiles and rockets was responsible for the arming signals the safety to be provided outside of that nuclear warhead and the fusing signals to tell it when to fire a 1953 agreement carved out areas of responsibility between the DoD and the AEC we ended up having to very specifically define where the interfaces were between the AEC hardware and the DoD supplied hardware the interface literally was a connector through which the signals passed to initiate the arming sequence of the warhead Sandia was becoming very concerned about supplying a warhead they just required an electrical input to detonate we're talking about delivering let me call them Baer warheads to the services a bear warhead would be vulnerable to any stray or intentional voltages and on the right pair of pins it could cause the weapon to go off a massive nuclear weapons complex had taken shape in less than a decade supported by an unbridled enthusiasm for all things nuclear the 1953 missile and rockets agreement was an addendum to a larger document spelling out a EC and DOD responsibilities for the complete lifecycle of nuclear bombs and warheads soon designers and engineers throughout the complex would discover and address the safety implications of this new generation of weapon systems all 1950 a fierce international war ripped through a small country on the north Yellow Sea called Korea Russia has successfully detonated an atomic bomb we need to develop and produce a greater number and variety and possibly even more powerful atomic weapons weapons tailored for specialized uses and targets the services wanted a nuclear weapon for every conceivable purpose in a report to the Joint Committee on atomic energy tactical nuclear weapons represented the future they promised a revolution in land war they were the natural answer to the armed hordes of the Soviet Union and their coming would immeasurably strengthen Western Europe's will to resist in the 1950s we saw weapons added if there were rate of about three different types per year the growth was dictated largely by the capacity of plants this is the mile-high City of masala Bo's the atomic City this is a modern Pueblo created by the people of the United States as a research and development center for atomic weapons nuclear weapons were the product of a demonstration of a brand new capability by Los Alamos and the adoption of that thought of military planners and whatever we could do they liked didn't matter what we owe he suggests that they liked it they were very good customers the early weapons were maintenance in intensive and required preparation time the mark 7 used perhaps 20 different complicated testers we at Sandia felt that these procedures were causing more damage to the weapon than they were finding in 1952 the mark 7 bomb was one of the first fighter delivered nuclear weapons but by the late 1950s the Air Force adopted a strike ready posture and capsule type weapons were deemed inconsistent with this new operational readiness what they were giving to the military in terms of hardware was burdensome hidden under this security cover the most destructive force ever devised by man an atomic bomb clearly the idea of having the military having to assemble a bomb didn't it all work with the five men and alert concept and that was the driver one of the drivers for wooden bombs in 1954 weapon designers envisioned a nuclear bomb that would provide operational simplicity or woodenness in which of the required operational maintenance and safety care approaches that of a piece of pine the concept was to try to come up with something a bomb to could withstand years in storage and be instantly available for military use in the earliest weapons those of lead-acid battery used which took three days to prepare characteristics of this type made it very difficult for the military to remain on alert one of the developments that enabled the wooden bomb was the advent of thermal batteries these were batteries that were completely inert until torch tissue robot the signal it was a dual pronged approach one go to thermal batteries become more test independent and at the same time I think in the penalty the physics labs we're trying to move towards a physics package design that allowed them to put the nuclear material inside the explosive itself Los Alamos is new sealed pit primary was proof tested at Yucca Flats sealed hid technology was a revolution and it allowed essentially immediate availability with the seal pit it was a package deal so to speak in the Nord of the military to be effective they had a control of the whole system we were always worried about what we call accidental nuclear detonation and when we had to seal pit we had to develop at the same time the concept of inherently one-point safe systems Duncan MacDougall at Los Alamos conceived of this notion that if you ignited the high explosive at a point it would consume itself meaning that if in an accident the high explosive were detonated at one point it would not lead to a nuclear event the calculations were done mainly by a man named Bob Osborne and the best we could do in guarantee was certainty was one chance in 1 million there to be no yield greater than four pounds and I had based this four pounds criterion on the basis that there might be an accident on a ship and the nuclear radiation from such an event could be contained within one of the compartments on the ship the new sealed pit primaries prompted a change in the safety emphasis from controlling the nuclear material to controlling the electrical energy in early 1957 there were 14 new weapon systems in the pipeline all based on Los Alamos as sealed pit design one of these 14 systems was the W 49 a warhead mated with the earliest intercontinental and intermediate-range ballistic missiles the 49 was the first of the warheads intended for re-entry vehicles that was small enough to be practical in a reasonable size missile and still have a large yield early on the Atomic Energy Commission provided the nuclear explosive package and a fire set and the Department of Defense was responsible for the fusing system which would delivers the proper signals to the warhead at the appropriate time to cause them to detonate arming and fusing signals together with the source of power were supplied to the warhead by the missile to be compatible with DoD systems you had to have an interface where the two came together and that was the form of at ordinary connector with pins and sockets I could remember in the military as a young lieutenant my favorite tool was a voltmeter because now I could troubleshoot the circuits in a logical way it was just a simple matter of moving a plastic cap for weather protection and doing these tests the concern grew about a friendly fiddler or someone who just mistakenly are connecting a voltage up and getting a very bad result a single individual with information about schematics which were widely available and a battery in Lynch box could detonate a nuclear weapon this was not good the W 49 was not considered to be an especially a dangerous system or different than any in the past it was just the time to begin stepping up to the plate changed the situation that existed in the past of not having some kind of environmental protection in the in the Sandia AC Hardware I took it upon myself to authorize the design modification if you will do provide a first generation environmental sensing device in this case an accelerometer no longer could you come up to the interface and put signals that would pass them down it was a positive block until sometime and the deployment to the target an environment was sense that would allow that signal to pass so there was an open switch literally the first open switch for safety sandhya would address this problem and oversee the installation of environmental sensing devices in bombs and warheads throughout the stockpile comprehensive stockpile safety began with the work of the influential CLE committee report that spawned nearly 70 safety studies culminating in a department of defense directive establishing formal safety standards for nuclear weapon design the CLE committee clearly influenced the future direction of safety creating the positive measures the positive majored concept was incredibly powerful in the sense of saying we need to see something that's engineered specifically for safety safety really means availability if you have a safe weapon you can deploy it anywhere in the world and not put the public at risk by 1960 sac was running an operation called positive control launch to ensure the survivability of its bombers this deployment of nuclear-armed b-52s would present new challenges for detonation safety an atomic bomb breaks loose from a mounting shackle in a b-47 jet over Florence South Carolina plummets to Earth causing a sensational freak accident a mark 6 gravity bomb accidentally dropped by an Air Force bomber was of the earliest generation of capsule type weapons no nuclear capsule was aboard the bomber or installed in the weapon and damage was limited to the detonation of the bombs high explosive the accident in March 1958 was the thirteenth involving air delivered nuclear weapons six months later the Strategic Air Command would begin to test its continuous airborne alert mission during the next ten years the air force would be plagued by accidents involving air delivered nuclear weapons we were running some fairly high risk operations we were flying a large number of airplanes and during most of the 50s and into the 60s continuously with nuclear weapons onboard hardware wears out things happen and the Air Force caught the brunt of of those issues their focus was reliability readiness not accident safety in the late 1950s Strategic Air Command began to carry sealed pit weapons where the bomb was loaded up and always ready to go accidents involving sealed pit weapons would represent a manifold change in the risks of an accidental nuclear detonation one of the earliest accidents involving airborne alert bombers occurred in January 1961 over Goldsboro North Carolina it was a normal flight it had just refueled with a kc-135 tanker the boom operator on the kc-135 told the pilot that he noticed a pink fluid leaking out of the right wing of the airplane pilot disengaged radioed in to sac headquarters to say that he had a fuel leak b-52's are a big flying fuel tank and it's necessary so that they stay at the air you've got a transfer of fuel from the center body of the aircraft out to the wings during one of these transfer operations the right wing of the airplane physically ripped off all of a sudden now that weapon system is free as the weapon dropped power was now coming on and the arming rods had been pulled the barrel switches began to operate the next thing and the timing sequence was for the parachute to deploy when it hit the ground it tried to fire there was still one safety device that had not operated and that one safety of device was the pre arming switch which is operated normally by a 28 volt signal some people could say hey the bomb worked exactly like design others can say all but one switch operated not one switch prevented the nuclear detonation unfortunately there have been thirty some incidents where the ready safe switch was operated inadvertently we're fortunate that the weapons involved at Goldsboro were not suffering from that same mal the accidents provided valuable information to AEC weapon designers at Sandia improvements were made in later generation pre arming ready safe switches unfortunately there was no shortage of new data as the accidents continued in January 1966 a mid-air collision over southern Spain raised international alarm the accident over Palomares I think was significant because of the scattering of plutonium on foreign soil it had incredible press coverage of that arena and an incredible negotiation between the US government and a Spanish government with respect to the level of cleanup we wound up buying up a lot of tomato fields over there after the accidents many things became more evident to us and the in fact to the world because there was such a stage that they could see now the US was embarrassed in a world community in early 1966 Strategic Air commands airborne alert mission codenamed chrome-dome had been operational for five years Robert McNamara who had been skeptical about whether the chrome-dome operation was still necessary wanted to put an end to it Strategic Air Command was able to argued that that was a very rare event it won't happen again we've Institute operational procedures so that there won't be another accident of that sort unfortunately they were wrong b-52 an airborne alert mission at a fire on board the aircraft crew evacuated the aircraft the plane then drifted without any one on board landed seven miles outside the base blowing up on the ice when the plane went down it tended to melt the ice and then plate the things so you had a layer of ice over the top of the contamination they had about 39 inches of ice when we got there and of course they wanted to preserve all that ice they could for cleanup and whenever there's an accident political authorities quite rightly say if we got this right sometimes we've said that accident was not so damaging it was a rare event and we can live with it other times they've said this was unacceptable these were fairly serious incidents they were international incidents and we had to come to some grips that perhaps we needed to adjust our posture and so we recognized that hey there's there's a high consequence event that can happen here it's unacceptable we have to deal with it out of that came what we call the Wolski criteria Karl Walski assistant to the Secretary of Defense Atomic Energy initiated a reappraisal of nuclear detonation safety in the wake of the 1966 polymerase accident but the 1968 accident at the Thule Air Base in Greenland became a catalyst for change the Walski criteria that was put out in 1968 gave two clear definitions of levels of safety for another eleventh the key factor was given an accident the likelihood of a nuclear detonation should be less than one in a million and one in a billion for just sitting there normal environments something that the US public in Congress and in the White House would understand so we put a number on the level of safety these accidents showed that you can have fire followed by crush followed by electrical insult a sequence of environments happening and that you may at one time deemed not to be credible but Nature has a way of voting mother nature's of devious adversary that's my personal view accidents are going to happen given the accident how will the hardware how will the weapon system respond well it goes the way I say it will predict it will design they will versus a system that's highly complex where it would not always fail predictably so given that we have developed a set of design principles from which we implement nuclear safety from the start into the weapon system design in response to the 1968 Walski criteria all three AEC Laboratories intensified their focus on safety Los Alamos would introduce insensitive high explosives Livermore would develop fire resistant pit technology and Sandia would establish the enduring concept of enhanced nuclear detonation safety underlying all of these developments was a new understanding indeed acceptance of the probability of an accident I think where we fou ourselves if we think we've thought of all the ways that accidents might occur the key thing for weapon safety is given the accident prevent to you the nuclear accidents of the 1960's shared common themes they all exposed the weapon to extreme environmental insult fire crush and electrical shock by 1972 Sandhya's independent safety assessment group would assemble evidence upsetting traditional understandings findings that would forever shatter the image of order conveyed to the designer by circuit diagrams and layouts creating an independent safety group I think was absolutely vital and probably the key to why improvements were made Jack Howard was strongly involved in encouraging an advanced development activity in a safety organization separate from the from the warhead developers if the design groups have somebody mentoring constantly in their ear saying always shouldn't there be somebody mattering never what we need is a simplifying notion so a small group was convened and I isolated them and said that don't want you working about day to day problems think this through and so what I asked for bill what we want to need some time some months to win and really try to now understand safety from a more fundamental viewpoint in 1968 Sandia designers asked are we doing what we need to be doing for abnormal environment safety their approach was twofold analyzed the safety features of existing weapons and exposed those components to severe abnormal environments the feeling at the time was things are pretty good we've had a lot of accidents we've never had a detonation people didn't at that time understand much about accidents but I think early on they assumed that things could fail in such a way that the system wouldn't work key assumptions at the time held that an electrical fault to ground will dud the weapon and that circuits and connectors will open up in an accident early detonation safety was achieved by employing ready safe switches environmental sensing devices like accelerometers by using printed circuit boards and cable isolation to ensure the electrical integrity of the safety system and safety was really on isolating the wires from the power coming in to pre arm the weapon for example from the charging circuits the early weapons were put together in such a way that this could all happen in the junction box and in the junction box you have the inputs and outputs together on a wiring board wiring Awards with all of these different paths and and then you maintain a separation between those paths and then you put an insulated material electrical insulation over the top of it you've made a cocoon around these items and they're going to be safe but those were safety features in essentially normal environments all of this hardware was developed in the vintage when abnormal environment was not considered once you start involving fire and and and unusual environments in that then you start shorting out cables and coming up with circuits that can cause a degradation of the safety that you built into the bomb after several years of intensive torturing of existing Hardware the study group found that the response was not predictable when test objects were subjected to thermal insult by an electrical fault the charred organic material would cease to insulate and now conduct electrical currents conduction and you can get conduction to many circuits in there in other words you're creating new electrical paths within this within your wiring board and those electrical paths could go through an arm the weapon system and pirate charred insulation or melted solder would not simply open up a safety circuit and dud the weapon but would cause unpredictable propagating damage further still there was no technical basis for this model of safety practiced among designers dare assessment and their analysis was not based on fact was not based on testing this was a great Eureka if you will in the safety arena that we need an approach that allows for unpredictability when you really start to build a safe nuclear weapon your first task should be to create a barrier system to isolate the critical power from your critical arming and firing circuit so you need a barrier area rise those and then you don't have to worry about what's happening outside it was a simplifying notion because now you didn't have to study all the ways things could go wrong so it made the problem manageable in 1971 the independent safety assessment group proposed a radical redesign of all weapon electrical systems beginning with the concept of an exclusion region where we isolate energy sources from critical nuclear weapon detonation elements to prevent a nuclear detonation exclusion barriers which are walls that contain capacitor discharge units are the energy sources that can light off the detonators for the system but you don't have an operational weapon make an operational weapon and you've got to essentially put a hole in the barrier to put in the arming energy when you need it and we did this to what we call strong links which are basically switching devices so you keep this electrical energy off these elements like detonators we used two strong links we were unwilling to assume that we had the skills necessary to devise a single switch that would give us 1 million protection each one has to be independently effective to avoid some common mode failure what you don't want is a common mode where with the same kind of input both devices would would fail so we used to designed differently and then your third thing you had to do is to make sure your strong links we're not susceptible to just common everyday voltages some signal that would not normally be postulated during an accident unambiguous indication of human intent is what it needs to open that gate that unique signal that was incompatible with all of the common voltages and the voltages as they may be modified by the abnormal environment ultimately the features of enhanced nuclear detonation safety were designed to prevent nuclear yield in the face of severe abnormal environments but eventually everything fails so now will will make it fail in a predictable way we deliberately designed some parts of the firing system to fail irreversibly such as a high voltage capacitor and so what you'd like to do is have something become inoperable and so that was a concept of a weak link and so you started co-locating the strong links with the weak link so that as the environmental insults arted to heat the weapon you have the weak link become inoperable before this strongly became ineffective and so out of that work came the basic principles that have really stood up for years isolation inoperability and incompatibility some people suggested a fourth principle of independence that makes you safe so that's that was the great breakthrough I think that stands Frei and his staff came out with enhanced nuclear detonation safety but strong links and weak links and meet the criteria above extreme safety that was a clean simple and most efficient way in which anything that failed for whatever reason would new to the system thinking back that's kind of an obvious thing maybe but we didn't have it until these folks invented it a requirement to change the design specifications so that you have more safety I think was just a gradual natural evolution because we were always concerned about safety of the devices especially as the number zone kept increasing and the deployment was pretty much worldwide in the northwest corner of South Vietnam rest the small valley of Khe Sanh the siege is on the north vietnamese launched a massive artillery attack u.s. commanders predict a major north vietnamese offensive just before the Lunar New Year on January 30th in late January 1968 the Johnson White House was consumed with the war in Vietnam coming just days before the North Vietnamese Tet Offensive the Tooley nuclear accident was almost a distraction mcnamara called for an immediate halt to sacks airborne alert program chrome-dome is canceled because of the embarrassment and the costs involved with having a second nuclear accident and yet the interplay between the warning system and the offensive capability that chrome-dome led us to have wasn't contemplated at the time indeed when the b-52 crashed outside Thule senior officials in the Pentagon really didn't know that the reason why it was so close to tule was because it was on this special tule monitor mission the b-52s on the airborne alert also had a second mission which was to look down at American air defense radars to make sure that they were working properly one of the concerns was that the Russians could take out one of the radars as a means of hiding the follow-on attack prior to major launch in the United States what happens if the airplane that crashed the nuclear weapons on board went off and destroyed the radar there's a potential for an accident to occur that could have cascaded into a false warning this kind of unusual interplay between a offensive nuclear system being kept up in the air a defensive warning system in the command and control never had been thought through is too unlikely an event a low probability event that you'd have both the airplane crashing and the nuclear weapons going off within range of the radar to destroy it but it wasn't infinitesimally small fortunately the one point safety system had been placed on those bombs worked but exceedingly rare events occur all the time generation exercises were a mainstay of sacked long after tule happened because they were no longer flying chrome-dome but they still want to maintain operational readiness we used to load the Bombers up with a full load of bombs and pull them on the end of the runway and go to take our fire roll down the runway and then chop the fire and go off the runway on the high-speed tacks away and taxi back to the murder because we wanted a realism we wanted assurance right up to pull back the yoke and take off that the crews could do everything these were oftentimes referred to as elephant walks so they continued to do all of the things of handling the bombs bringing them from the storage area installing them on the clippings putting them up on the Bombers and everything short of flying them these could be fully loaded airplanes fully loaded with fuel and so it was quite taxing on the brakes to do this and a number of situations occurred where the aircraft actually caught on fire because of hot breaks sac was continually putting themselves and the weapons at risk conducting these ground alert operations it was generally well accepted by both the civilians and the military civilians may see in the military that we had to have a posture it was survivable in the interests of survivability we have accepted some risks two departments have worked together very well in trying to mitigate those risks positive measures mitigating the safety risks of nuclear weapons were formally established in 1960 and from the beginning nuclear detonation safety was conceived of as a shared responsibility it's the principal responsibility of the Department of Defense to assure that the abnormal environments don't occur very often in fact at a diminishing low level but it is the laboratories responsibility to assure that given an accident that that will not be allowed to progress to a nuclear detonation in late 1970 two years after the Sandia safety study group began its work the weak link strong link concepts were formally briefed to the DoD but acceptance of this new standard for safety design came slowly some of the discoveries were actually disbelieved by number designers they wanted to believe their nice orderly world the one they were trained in and raised in this is a way electrical circuits behave so we arranged to make a display called the burned board briefing people were seeing actual examples of what could happen they were not just seeing view graphs and words about what might happen they were seeing Hardware about this you know this could happen the idea of a burned board briefing originated with Bob Purifoy after leading Sandhya's successful design effort for the Navy Purifoy became director of weapon development and undertook a complete review of the stockpile I quickly became concerned about electrical system designs that would tolerate severe accidents those bombs that used high-voltage thermally activated batteries so all of those weapons could possibly be armed in the case of a fire that set off the high voltage thermal battery the electrical systems of greatest concern were those of air delivered weapons on alert those loaded up during sacs generation exercises in spring 1974 Sandia vice president Glenn Fowler briefed the labs concerns to the division of military application at a EC headquarters there was some reluctance on their part to greet that with any enthusiasm the DoD felt I think that what they needed was more war fighting capability they had enough safety Fowler and Purifoy decided to go on record with their concerns Glenn's memo expressed that these weapons should be upgraded with modern safety features or retired right away people were indignant that the labs would blow the whistle on themselves words coming from the designers themselves can't easily be dismissed as possibly false and that caused no end of hysteria in Washington the burned board briefing was arranged as a demonstration for key Washington decision-makers among the first to receive the briefing was the assistant to the secretary of defense for atomic energy Don Cotter a former Sandia Cotter found the briefing a sobering experience in May 1975 he issued a directive for a joint safety evaluation of the entire stockpile give the DoD credit once they decided to go do the stockpile review they went at it with you know enthusiasm and I think with a real hard look not only this time at the weapon but at the weapon system beginning in the summer of 1975 joint technical working groups were formed to evaluate each category of weapon and weapon system against modern safety standards this was a joint review process we had people from the laboratories and from the Department of Defense working together as a team to review the system strategic air delivered weapon systems on alert were given first priority the conclusion of the safety studies in spring 1977 coincided with more than a decade of advanced development work yielding the first air delivered weapon to fully incorporate enhanced electrical safety the b61 mod 5 the b61 got its start in the early to middle 60s everybody on the team would get a pep talk that we were working on the Cadillac of all bombs the design architecture of the system was such that it allowed for a continuing set of improvements for achieving improved safety particularly as well as improved use control this inherent safety and security would in time make its way through the rest of the modern stockpile the b61 established a modular architecture for nuclear weapons the fine set and the original 61 eventually were replaced with firing sets and roughly the same volume that had modern nuclear safety features and capabilities all integrated into the firing set and that's why packaging becomes so important when you're first laying out the design of a nuclear weapon you can clearly put in strong leaks and weak links and have them totally ineffective that they're quite some distance apart and that's where in reason we co-locate and put them basically within the firing system itself the modernization of the weapons systems didn't happen overnight there were units that were out there that had no modern safety associated with them it became more and more apparent that we need to review our entire stockpile improvements to older air delivered systems began in 1979 a time when east-west relations were descending to new lows during the 1980s strategic and conventional Arsenal's expanded on both sides a global anti-nuclear protest movement emerged nuclear arms control efforts were re-established and the nuclear accident galvanized world opinion mr. Gorbachev tear down this by the end of the decade sweeping political changes had overtaken well-laid plans for weapons system modernization and era had ended when older systems were routinely replaced with new and safer designs ensuring the always and the never of nuclear weapons would at once become more public and more challenging you

Channel: Sandia National Labs

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Keywords: Sandia National Laboratories, Safety (Quotation Subject), Security (Quotation Subject), History Of Science (Field Of Study), Stockpile Stewardship

Id: sb2qo5m_hTY

Length: 54min 32sec (3272 seconds)

Published: Mon Jun 15 2015