Mark HibbsLooking Back at Brazil’s Boreholes

On September 18, 1990, long-held suspicions about Brazil’s nuclear intentions seemed to be officially and dramatically confirmed. Brazil’s first popularly elected President in 29 years, Fernando Collor, on the scene of what his aides suggested was a nuclear test site, terminated a covert nuclear weapons project which had been steered by the military. The New York Times reported it out from Brazil:

In a first step to dismantle the bomb project, Mr. Collor flew photographers and officials to a previously off-limits air base in the Cachimbo mountain range of remote central Amazon. As the heads of the three military services watched – looking ill at ease in the photographs – the President threw a symbolic shovelful of cement into a hole four feet in diameter and 1,050 feet deep.

I read this article the day after it appeared in print, and its conclusion–neatly summarized by the International Herald Tribune‘s front-page headline: “Brazil Uncovers Plan by Military to Build Atomic Bomb and Stops It”–has been with me and has probably subconsciously influenced my thinking about Brazil’s nuclear program for nearly a quarter-century.

Last month, my colleague Togzhan Kassenova published this account of Brazil’s nuclear program. Her introduction included these remarks about frequently encountered narratives that try to explain what Brazil was doing in the nuclear energy field:

“Brazilian” voices are less heard, outside of official statements, are are quite different from the external observers. Whereas the commonly accepted external view is that Brazil pursued a nuclear-weapons program, Brazilian political, technical, and intellectual elites still debate whether the country undertook such an effort.

Many people living in the northern hemisphere might be surprised to learn that Brazilians don’t agree about what we had been told decades ago was an open and shut case: that Brazil had a secret nuclear weapons program, and that a charismatic, vigorous, and democratically-empowered leader shut that program down. What was there to disagree about? After all, the Brazilian government itself exposed the project to the world. Weren’t those holes at Cachimbo all the proof that Brazilians required to conclude that their country was secretly working on nuclear weapons and, further, that the masterminds were probably far enough along to begin preparations for a nuclear test?

Collor’s photo-op at Cachimbo is just one detail in a long cat-and-mouse history of Brazilian nuclear activities. But prompted by Togzhan’s passage about the importance of nuclear narratives, I decided to look into that detail and see for myself if what the New York Times was told then matched what Brazilians conclude about this matter today.

I found some “Brazilian voices” which were in and around the nuclear program when these events began unfolding after Collor won a run-off presidential vote at the end of 1989. What they relate significantly qualified the picture at Cachimbo which in 1990 seized the imagination of the outside world and which has lingered in our collective memory.

What Collor Knew

In September 1990, government officials told reporters that military officers shocked the President by disclosing a clandestine nuclear project, and after a stormy confrontation, Collor flew into Cachimbo with a bevy of top officials and reporters and filled up one of two bore holes (one participant last week told me there were in fact three holes) with cement (I was told instead that he used lime).

Last week I was also reminded by Brazilian sources that in 1990 the holes at Cachimbo had already been known to the Brazilian public and parliament for four years, after local media reported that the Air Force beginning in 1981 had systematically studied the terrain’s geology and hydrology and then drilled shafts meant for a nuclear weapons test or for disposing of nuclear waste. The government brushed off the story, but the holes weren’t a secret.

Brazilian witnesses in all of this told me that, shortly after Collor won the 1989 election, the military asked him to support their nuclear project, as they had asked his predecessor Jose Sarney. Collor, I’m told, would not agree, and thereafter prepared to exploit the Cachimbo matter for all it was worth.  For starters, Collor aimed to curb the Brazilian military’s independence in nuclear affairs–first and foremost by short-circuiting officials in the Army and the Air Force who under Sarney had been angling for political and financial support to develop the capability to conduct peaceful nuclear explosions (PNEs). “Collor was a genuine public relations talent,” one former official recalled, and “the holes in the ground were, in effect, a hoax.” During the 1980s, he said, “some people in the military wanted government money for their own nuclear projects, and they couldn’t get it unless they showed that they were making progress. That’s why they drilled the holes.”

When Collor’s officials inspected the shafts, they found that they were worthless for testing nuclear explosives. There was no cabling or other support infrastructure, and the bottom of the holes was full of water. The shafts weren’t perpendicular. “If anyone would have tried to test a  nuclear bomb in there, they would have failed,” the former official said.

The military ruled Brazil from 1964 until 1985, and in retrospect it would appear that the holes at Cachimbo provided Collor a golden opportunity to set back potential adversaries to civilian rule. But other things were on his mind as well. Beginning in 1980 Brazil and Argentina embarked on a bilateral nuclear cooperation relationship, and both Collor and Argentine President Carlos Menem, elected a few months before Collor, were committed to deepening it. Demonstrating that civilians were firmly in control of Brazil’s nuclear program would help. Collor’s biggest domestic challenge was to defeat hyperinflation. Part of the recipie was to generate international confidence, and filling the holes was in step with a broader message that Collor’s leadership would be transparent, reliable, and dedicated to international cooperation.

Brazil and PNEs

Brazil was interested in PNEs from the beginning of its nuclear program. This cable shows that the U.S. Department of State was closely following Brazil’s interest in PNE’s as early as 1967. Brazil wasn’t alone in looking into PNEs in those days, of course, but because it was not a party to the Nuclear Nonproliferation Treaty its interest–like South Africa’s–didn’t preclude that the technology would be used for atomic weapons. Brazil’s military was, in fact, keen to pursue the PNE option, and, eventually, it was the Army and the Air Force that pressed to do PNE work, while the Navy instead set its sights on centrifuge uranium enrichment and development of a propulsion reactor for submarines.

In South Africa, a PNE program morphed into a secret program to develop a  nuclear weapons deterrent. In Brazil, the trajectory of the military’s PNE interest was blocked by civilian leaders, so the nature of Brazil’s interest in nuclear explosives was, in the view of Brazilians I talked to last week, more ambiguous. But not long after his Cachimbo appearance, Collor formally repudiated his country’s interest in PNEs before the United Nations General  Assembly.

In 2009, a Brazilian research scientist at the Army Technology Center (CETEX) published his doctoral thesis presented to Brazil’s Institute of Military Engineering, containing many details on the science behind nuclear explosions. The publication led to questions from the IAEA about the relationship between the author and the military’s nuclear legacy. The U.S. government may also have had questions about references in the text to U.S. warhead development. There were initial differences of official opinion about how Brazil should respond, and problems with the IAEA. Defense Minister Nelson Jobim ultimately dismissed the matter as irrrelevant to Brazil’s nuclear program. “The mere possibility of publishing this work in Brazil, and the material’s free circulation, serve as eloquent proof of the non-existence of an unauthorized nuclear program in the country,” Jobim said. But could information in the book have come from Brazil’s military past?

A More Nuanced Context

Every country that partakes in nuclear activities has an official narrative to explain these activities to the world. Here are 111 of these narratives from 2013, all posted on the IAEA website.

Brazil’s narrative has evolved over time, subject to both internal and external developments. Re-examining the record of events from a quarter century ago, it appears that Brazilians have walked the government’s 1990 story line back. What transpired at Cachimbo then appears to have a different context today where these elements prevail:

  • Collor viewed Cachimbo as an opportunity to throw the military onto the defensive while demonstrating to Argentina, the U.S. and others that his government would be a reliable foreign partner
  • Prior to the Cachimbo event Collor had been interacting with the military for nearly a year including about its current and future nuclear ambitions.
  • In 1989-90 all three branches of Brazil’s military sought government funding and support for nuclear activities which Collor was not willing to provide.
  • Collor and his aides were particularly determined to prevent the military’s pressing interest in a PNE project from becoming a nuclear weapons project.
  • During the 1980s the Air Force dug the holes at Cachimbo to convince Sarney it was making progress related to a PNE effort. Collor found out that the shafts could not have been used to test nuclear explosives or dispose of nuclear waste.

In 1990, Brazil’s new civilian leaders made a dramatic statement that was intended to hold the military at bay and assure the world that the new government would be a reliable and transparent partner–including in line with global concern about nuclear weapons proliferation which would intensify as soon as the first Gulf War was over. Collor stepping into the breach to symbolically crush what was described as a secret nuclear weapons project helped convey that message.

Today, witnesses to those events present a more nuanced and modest picture. They recall now that some personalities in the armed services wanted a more ambitious, military-run nuclear program including a PNE effort, but also that no Brazilian government had ever approved or funded this, and that Brazil’s “secret nuclear program” was less a reality than it was a vision entertained by its advocates.

Prior to Collor’s election, denials in Brazil and elsewhere discouraged Brazilians from seeking the whole truth about their country’s nuclear activities. During the 1980s, senior Brazilian nuclear executives seeking foreign cooperation routinely claimed there was no “parallel” nuclear project. German government spokesmen asserted on the record–in contradiction of Bonn’s own intelligence findings–that Brazil’s nuclear program had no military dimension.

Today, Brazilians have better resources to help them draw their own independent conclusions. Researchers led by Matias Spektor at the Fundacao Getulio Vargas are reconstructing the history of Brazil’s entire nuclear enterprise. What they are finding so far documents a long-term interest in both PNEs and nuclear weapons in Brazil, but also that there was never a top-down nuclear weapons effort anywhere in the government, and that Collor, in addition to keeping the Army and Air Force away from nuclear matters, also defunded the Navy’s nuclear program. A chunk of the research, from Carlo Patti, is here.

One critical piece of evidence in the government’s 1990 story has never been confirmed. The New York Times reported that Collor acted in response to a “50-page classified report” on the secret nuclear program which had reached his desk. That report has never surfaced. Some people in and around Collor’s government last week suggested to me that its existence may have been a rumor.

Did Brazil’s military in the past harbor hidden nuclear weapons ambitions? Were the services actually doing any work on nuclear weapons development? One government adviser told me the answer was a qualified yes. “There was a secret project, but it was at a very preliminary stage” when it was interrupted in 1990. Since  then the version of events reflected in the New York Times story has largely prevailed in the United States. But Brazilians have moved on. The 1990 narrative has been revised.  That may have led a few people to claim that Brazil never had any interest in nuclear weapons, but, far more importantly, it may have encouraged Brazilians to be more confident about their country’s nonproliferation profile.


  1. Carey Sublette (History)

    “In South Africa, a PNE program morphed into a secret program to develop a nuclear weapons deterrent.”

    I think it is highly credulous to think that any of the non-weapons state programs launched to pursue “PNEs” (India, South Africa, Brazil) were ever anything but cover for a nuclear weapons program.

    The economics of a “PNE”, if is is not already available as a by-product of an existing nuclear weapons production line, is fantastically unfavorable. It is unfavorable even with all of the start-up cost already underwritten by the weapons program.

  2. Stephen Schwartz (History)


    While the 2009 doctoral thesis by Brazilian graduate physics student and research scientist Dalton Ellery Girão Barroso may shed some light on Brazil’s past nuclear activities, the references and calculations therein concerning a US nuclear warhead are far less troubling than they first appear.

    It’s clear why the title of Barosso’s thesis, “Numerical Simulation of Thermonuclear Detonations in Fusion-Fission Hybrid Environments Operated with Radiation,” raised concerns inside the IAEA and elsewhere. According to a translation and summary in Brazil Magazine on September 7, 2009 of the original article in Jornao do Brasil, Barosso “interprets physics and mathematical models of the W-87 warhead developed by the United States. ‘You don’t need to make the bomb,’ says Barroso. ‘You just have to show that you know how to do it.'”

    What struck me at the time was the reference to the W87, which until 2005 was deployed atop MX/Peacekeeper missiles and subsequently redeployed on 250 Minuteman III ICBMs. Why had Barroso chosen that particular device?

    The answer lies in a September 9 editorial in Jornao do Brasil. Translated, it explains:

    “Far from posing a threat to international security, the Brazilian physicist’s feat was obtained legitimately through his intellectual efforts. Barosso created a computer program that deciphered data on a W-87 warhead, leaked in 1999 in a report published by Insight Magazine, an American publication.”

    This is where things get interesting. On August 9, 1999, Insight, which was owned and operated by Rev. Sun Myung Moon’s Unification Church, published an article by physicist Sam Cohen, the controversial inventor of the so-called neutron bomb. Cohen sharply criticized the recently published report by the House Select Committee on U.S. National Security and Military/Commercial Concerns with the People’s Republic of China, better known as the Cox Committee after chairman Rep. Christopher Cox (Republican of California), for publishing “highly classified information” and thus committing “a gross security violation.” In particular, wrote Cohen, “the Cox report presents a beautiful multicolored diagram that details the workings and components of [the] highly classified [W87] warhead.” Here is that diagram (from page 78 of the report).

    Cohen continued:

    “The [diagram] provides an extremely useful blueprint for use by Pakistan or India … that they can use to advance their thermonuclear warhead programs. Why would the United States, a dedicated proponent of the Nuclear Non-Proliferation Treaty, want to enhance proliferation of thermonuclear warheads by publishing a detailed, classified design of one of its most advanced models in an unclassified congressional report?”

    Barroso’s interest in the W87 now becomes clear. However, the diagram in question is neither classified nor especially accurate. As Steven Aftergood of the Federation of American Scientists reported nearly fifteen years ago, the drawing in question originally appeared in the July 31, 1995 edition of U.S. News & World Report, a fact of which Cohen was unaware until Aftergood pointed it out. And as Aftergood noted, "To the untutored eye, the drawing appears to contain little more than the information that was previously published by the Progressive in 1979, including at least one of Howard Morland’s original errors.” Furthermore, the image, both as originally published and as reprinted in the Cox Report, clearly lists the sources, including the Natural Resources Defense Council, which provided only basic, long-available open source information about the warhead to the magazine, leaving a graphic artist to do the rest.

    (Also unaware of its provenance was Rep. Curt Weldon (Republican of Pennsylvania), who, as recounted by Aftergood, took to the House floor no less than three times after the original U.S. News & World Report article was published to castigate the Clinton administration, and specifically Secretary of Energy Hazel R. O’Leary, for deliberately leaking “the design of the W87 warhead” to the magazine.)

    The Jornao do Brasil article and other Brazilian publications claimed back in 2009 that Barroso, and by extension Brazil, now know everything there is to know about building nuclear weapons. I think not.

    • mark (History)


      Thanks for the welcome detail. It is appreciated. In my view–and my view matters because I’m one of the chosen few who are running and editing comments on this blog however I am quite confident that my view is shared by my colleagues–what you provided is exemplary of the kind of information and background which the comments should provide.

      That said, I ask: What is there to say about whether Barroso tapped any information which, through his affiliation with CETEX, IME, or any other institution affiliated with Brazil’s military, he was able to obtain related to any theoretical work that may have been carried out by scientists in Brazil who, prior to 1990, were part of a military-led effort to establish a PNE project.

      According to some foreign diplomatic cables, Brazil initially refused to allow the IAEA Department of Safeguards to interview Barroso. I am informed that at some point later IAEA personnel did in fact meet with him. Certainly they would have raised the subject of the origin of the findings and information published in the text. A subsidiary question would be what would have been the basis of Brazilian sensitivities about this issue? Matters of substance? Or, instead, perhaps, matters of principle related to Brazil’s strict understanding of what its formal obligations are to the IAEA under its safeguards agreement, in absense of an Additional Protocol, and its overarching Quadrapartite understanding with the IAEA, ABACC, and Argentina?

    • Stephen Schwartz (History)

      All good questions, Mark. Barrosso clearly knows something, and there’s a lot of unclassified information out there on which one can draw to make reasonable inferences about the basic design and yield of nuclear weapons. But reverse engineering a W87 in a computer from that unclassified, unofficial image would not, I think, provide much meaningful or reliable data. To my mind, for Barrosso to obviously not understand the origins of that image and then make it the apparent centerpiece of his work calls into question his methodology, calculations, and findings.

    • Bob Kelley (History)

      Regarding the W-87, remember this is the same period as the revelations about the W-88 possibly been compromised to China. The cartoons about that loss are similar to the cartoon described by Mark ( ) and were produced by a graphic artist working for the newspaper from oral instructions.

  3. nukeman (History)

    Barroso may have used openly published US information regarding nuclear warhead design but he may also have used information from Russian, Chinese, French, UK, etc. scientific articles. By the time he had published his thesis Russian information on EOS and shock compression for U, Pu, and other materials had been available for over ten years. US published articles and documents should not be thought of as the only source of information when it comes to nuclear device related info. I would take what the Russians have published over the US any day. Sadly this reflects on the current state of US science and technology over the past six years.

  4. Bob Kelley (History)

    When Collor’s officials inspected the shafts, they found that they were worthless for testing nuclear explosives. “There was no cabling or other support infrastructure, and the bottom of the holes was full of water. The shafts weren’t perpendicular. “If anyone would have tried to test a nuclear bomb in there, they would have failed,” the former official said.”
    Not a well-informed former official. Many tests were conducted below the water table. Plenty of engineering solutions. The French tested under salt water lagoons in the South Pacific. Perpendicular is an odd choice of words. If it is straight enough to lower a device that would be adequate for a simple test. And cabling does not lie around for years waiting for the device. It will come at the time of the test.

    • mark (History)


      Now that’s interesting.

      Doesn’t what you say imply that, in general, if someone builds a deep hole or shaft (to give it a somewhat more respectable appelation) in the ground, pretty much any hole or shaft, that hole could be used for testing a nuclear explosive? If not, what would be the general criteria to decide whether a hole in the ground could be used for such a purpose? Putting it another way, if someone were to tell me, “this hole couldn’t have been used for testing,” he or she would have to give me X, Y, or Z, reasons for that statement to be valid–not the reasons he or she provided and which I cited in the blog post.

      And furthermore, does your comment imply that, prima facie, an assertion put forth that “that hole couldn’t be used for a nuclear weapons test” would likely be either: a.) based on other evidence, which is not brought forward, which would explain why it couldn’t be used (what evidence could that be?) or instead b.) that the assertion is specious and is simply an irrelevant rationalization to support a revisionist thesis which has been advanced for reasons not pertinent to the question of whether the site would be suitable for nuclear explosives testing?

      While writing this post I came across a flurry of leaked and declassified U.S. diplomatic cables over a period of about 35 years. These testify to… um… let’s call it a robust U.S. interest in the question of whether Brazil would move forward with a PNE project. Surely there must be somewhere a USG technical evaluation of the evidence about what was on the ground at Cachimbo.

      In this regard I also wonder if perhaps that apocryphal “50-page classified report” mentioned by the New York Times which allegedly motivated Collor to take action on all of this in 1990 might have been based on information which the USG itself accumulated in its intellgence files and then provided to Collor after his election to strengthen his resolve to put an end to ambitions of his military in the nuclear area. After all, a subtext of the Brazilian narrative on Collor is that the Cachimbo episode was in part a testimony to Collor’s desire to impress the outside world, and above all the U.S., that Brazil was keen to cooperate with the international community on multilateral issues, from monetary and trade policy to WMD prevention. Did the prospects of a closer relationship with Brazil under Collor prompt the USG to share what it knew about the military’s nuclear activities with the new President?

    • Cheryl Rofer (History)

      I’ll agree with Bob that tests have been done below the water table and that emplacement of cables would be done at the time of the test.

      A question that came to my mind as I read the post was containment, which could be part of Mark’s question a. Is the geology suitable? If drilling equipment was brought in, it certainly would be possible to bring in the containment materials, so their absence doesn’t prove anything. Like the cabling, they would have been brought in at the time of the test.

      I was also wondering about the diameters of the holes. Again, this wouldn’t be determinative, but one more piece of information.

      If the test was to have been clandestine, containment would have been an essential part of that. And by 1990, containment technology was pretty well developed, at least in the nations doing underground testing.

  5. Bob Kelley (History)


    For starters you say this is for a PNE. What kind of PNE? Cratering or canals? Awfully deep at 1050 meters for that. For petroleum stimulation, mining, well-fire suppresion? Is there any information about what sort of PNE they were considering? Or is it a shot across the bow PNE like Smiling Bhudda? Then you think about diameter. That is pretty important and if the hole is not straight it could give you insertion problems. If they have a robust enrichment program they could go with very small diameter gun-type assemblies. Diagnostics? Do they need a clean line of sight all the way to the surface? Doubt it for their first shot.
    A good reason not to use a hole would be the discovery of a serious nearby fault as in Baneberry.

    I’ll leave it to you to speculate on intentions, truthful or otherwise!

    • mark (History)


      I’m told that Carlo and Matias, referenced in the text, have confirmed in their documentary examination of Brazil’s nuclear history, that there was interest in nuclear weapons and in PNEs in Brazil.

      I don’t know if they were the same people, or whether “weapons” and “PNEs” were considered interchangable by advocates of nuclear explosives development.

      Keep in mind that the holes were supposed to be for a test of a nuclear explosive, whether for weapons or a PNE I did not say. I was told that the people in the military who told the government they wanted to do a PNE program, in the Air Force, dug the holes at Cachimbo.

      I’m not interested in speculating about whether the views of people in Brazil I talked to about this recently–including people who were in the government and in the nuclear program at that time–were based on any alterior motivation. I’m only interested in the facts in the case.

  6. Cthippo (History)

    It sounds like politics all the way through.

    You don’t need a hole until you have a device to test in said hole, and then the characteristics of the hole will be driven by the expected capabilities of the device. In this case, the Brazilian military were nowhere close to building hardware but needed to show that they were “doing something” and so dug the holes.

    Likewise, the project died for political reasons and the filling in of the holes was as symbolic, and arguably detached from reality, as digging them in the first place.


    The diameter looks like about 4 feet to me, but I suspect that size is more a function of the largest boring bit they had rather than what they actually thought they needed. Certainly the size and characteristics of the shaft can tell an observer a lot about the device that is intended to go into it, but only if the progression is device then shaft. When the motivation is “look busy” then all bets are off.

    • mark (History)


      You say:

      “… the Brazilian military were nowhere close to building hardware but needed to show that they were ‘doing something’ and so dug the holes.”

      That’s what the Brazilian ex-official told me.

  7. yousaf (History)

    Agree with Carey Sublette.

    Also, while I think theoretical studies such as that by Dalton Ellery Girão Barroso are not a problem in themselves, and certainly not covered by CSA, and therefore none of the IAEA’s business, I also think that all NPT NNWSs should be treated similarly if works like “Numerical Simulation of Thermonuclear Detonations in Fusion-Fission Hybrid Environments Operated with Radiation” are found in their military institutes and/or on alleged laptops of uncertain provenance.