Neutral Sweden Quietly Keeps Nuclear Option Open

Thursday, November 24, 1994

In the Stockholm suburb of Agesta, a small rock hillock rises amid pine forests and horse farms. It might be just another playground for Scandinavian climbers but for one startling feature: Protruding from the top of the mound, like a missile peeking from a silo, is the conical tip of a nuclear reactor cooling tower.

Thirty years ago, this 65-megawatt reactor buried 50 yards deep and capable of sizable plutonium production was a key component of a vigorous Swedish program to develop a nuclear bomb option, a project that at its Cold War height secretly employed 350 scientists and technicians at the Defense Ministry.

Now international nuclear inspectors are discovering that some key elements of that Swedish bomb project have been quietly preserved for the more than 25 years since Sweden pledged to be a nonnuclear state.

For two decades, Sweden has maintained its underground Agesta reactor in a condition that would permit start-up on relatively short notice, probably within several months, Swedish and other officials said. Until this fall, Sweden did not formally disclose this fact to the International Atomic Energy Agency (IAEA), the authority that monitors compliance with the nuclear Non-Proliferation Treaty, which Sweden signed in 1968. It finally did so in September as part of a voluntary, confidential experiment to help broaden and strengthen IAEA safeguards.

Moreover, Sweden continues to maintain at its National Defense Research Establishment a small team of theoretical physicists who research nuclear weapons technology, according to the program's director, Tor Larsson. Besides current research on such topics as the theoretical performance of a nuclear bomb and the effects of nuclear explosions on a convention al military battlefield, these Swedish defense scientists possess an archive of preliminary design and technical data on nuclear weapons, the legacy of Sweden's Cold War-era bomb project.

Swedish officials deny that any of this constitutes an effort to hold a nuclear weapons option in reserve. The continuing nuclear weapons research is for defensive, safety and counterterrorist purposes only, they say, and the quiet maintenance of the Agesta reactor was done for technical and safety reasons, not because of defense policy. Building a nuclear weapon "is not an option for Sweden," said Deputy Defense Minister Peter Lagerblad. "We have no will to do it. ... It's out of the question."

Yet some Western analysts remain skeptical of these explanations -- not because they believe Sweden intends to build a nuclear bomb anytime in the foreseeable future, but because its quiet preservation of Agesta, its archive of past weapons research and its continuing research at the Defense Ministry seem to provide evidence of a plan to maintain indefinitely the key technical components of a nuclear weapons option.

"In another country, a buried reactor like that would be seen as a serious nonproliferation problem," said an official familiar with the Swedish program.

The Swedish case is an example of an emerging nuclear proliferation issue in the post-Cold War world. It concerns what specialists call "virtual weaponization" programs by sophisticated, industrialized countries. Such programs involve research into key elements of a nuclear weapons capability as a hedge against an uncertain future or for defensive purposes -- research that is often permissible by the letter, if not necessarily the spirit, of the nuclear Non-Proliferation Treaty.

Japan, Germany, Italy, Switzerland, Canada, South Korea and Taiwan are all believed by Western analysts to have conducted at least some secret nuclear weapons research as a hedge during the Cold War period. Some may be continuing aspects of that work today without necessarily violating their treaty obligations.

By its recent decision to volunteer for the experimental IAEA program, and because of the extent and ambiguity of its past and present nuclear weapons research, Sweden is opening a window on the depths of the virtual weaponization problem.

At the same time, the post-Cold War declassification of Swedish government documents and the growing willingness of Swedish defense scientists to talk openly about their nuclear weapons work are steadily lifting the lid on a bomb project whose full extent and rationale remain little publicized and poorly understood, even by many Swedes.

Although Sweden recently has taken a number of steps to open its nuclear past, the government has yet to embrace a policy of total transparency. Some documents about the nuclear weapons program remain classified, the program never has been formally scrutinized by international inspectors, and the preserved condition of the Agesta reactor has not been disclosed publicly until now.

Swedish defense scientists said the country holds onto some remnants of its nuclear weapons program today for the same reason it was begun in the first place: The work is seen as necessary to preserve traditional Swedish independence and neutrality.

"I think that if we don't know anything at all about nuclear weapons physics, then if any [nuclear terrorist] case might occur, whatever it might be, then we will be obligated to go to Brussels or London or Washington, D.C., or Paris to ask for their guidance," said Larsson, program manager of the Defense Ministry's nuclear weapons-related research. "This is not something we would want to do as a neutral state. As long as we profess to stand on our own feet, I think we can afford to have a handful of people to work [on] and understand these problems."

Yet the issue remains uncomfortable for a generation of Swedish politicians who stridently championed nuclear disarmament during the postwar period while secretly conducting nuclear weapons research and collaborating closely with NATO on contingency plans for a European war. Swedish defense scientists also engaged in secret exchanges with U.S. nuclear weapons scientists.

The Swedish government never has explicitly acknowledged that it sought to acquire nuclear bomb capability. In 1985, a Swedish technical journal revealed some details of the weapons program and suggested the project was designed as late as the 1970s to keep open an offensive nuclear weapons option -- that is, the capability to make and deploy tactical or strategic weapons. A government commission later attacked some of the technical journal's findings, although it acknowledged that the weapons program had existed. The government asserted that its nuclear weapons research had been solely defensive, meaning it studied the threat of nuclear explosions to conventional forces and civilians.

But recently declassified documents and statements by scientists involved make clear that Sweden -- a country of 8 million people with a long tradition of neutrality and vigorous defense spending -- did seek to develop an offensive nuclear weapons option until at least the 1960s and that the buried Agesta reactor south of Stockholm was a key element of that program.

Olof Palme, the longtime Swedish prime minister who often irritated Western governments with his pious campaigning against nuclear weapons, was the secretary of a secret 1958 committee that decided that research on a Swedish nuclear weapons option should continue, setting the stage for the program's most vigorous phase during the 1960s, according to a history of the program recently prepared by Jan Prawitz, a visiting scholar at the Swedish Institute of International Affairs and a longtime participant in the weapons research.

In 1985, when the technical journal's revelations were published, Palme said in an interview that he was ordering a thorough government investigation because "maybe, sometime" the Swedish military "has done research that went out of bounds." In the interview, the closest Palme came to admitting his own role was an acknowledgment that while he once considered nuclear weapons a viable option, "I became more moral as the years went on."

The underground Agesta reactor has been shut down since 1974. It has been preserved with regular maintenance visits since then, and some mechanical sections of the reactor have been used for decontamination experiments since the formal deactivation, Swedish nuclear regulators said.

"I don't think 'mothballed' is the right word -- it was just left for future full decommissioning," said Lars Hogberg, director general of the Swedish Nuclear Power Inspectorate. "The main reason for that is that we realized we had to develop sophisticated decommissioning and waste handling."

Yet this explanation is not fully consistent with the history of Sweden's nuclear decommissioning program. Another, much smaller underground research reactor of similar design to Agesta was fully dismantled after deactivation in the mid-1980s. Swedish nuclear regulators said the difference in treatment of the two reactors might be due to their different sizes and materials, but as they were not directly responsible for the decisions, they could not be sure.

The pressurized, heavy-water-moderated, natural uranium-fed reactor at Agesta is of a design comparable to that which produced the plutonium for the U.S. nuclear bomb dropped on Nagasaki, Japan, in 1945. Constructed as a prototype, at peak operations it could produce enough plutonium-239, a key bomb ingredient, for one or two nuclear weapons per year, according to Prawitz.

The reactor site and the full scope of its activities never were under international safeguards, Swedish nuclear regulators said. A few fuel assemblies provided by the United States for experiments were briefly under safeguards in the early 1970s. The reactor's technical profile appeared in some public IAEA literature of that period, but the site dropped off the safeguards screen after Sweden signed up for comprehensive safeguards under the Non-Proliferation Treaty in 1975.

Because it has been dormant for two decades, the site was not officially declared to the IAEA until this fall, as part of the experimental program in "expanded declarations" of a country's full nuclear activities.

The present IAEA safeguards regime focuses mainly on active stocks of fissile material, not on inactive facilities, laboratory experiments, theoretical weapons work or "dry run" weapons-design projects. The question circulating at the IAEA and elsewhere these days is: Now that the Cold War is over and nuclear nonproliferation is a global priority, how can the present safeguards system be overhauled to help ensure that "virtual" weapons programs do not suddenly become actual ones?

Sweden's government is said by officials and scientists to be considering whether to go even further than its present voluntary experiments and invite weapons specialists attached to the IAEA to review the full history and scope of Swedish nuclear weapons research and development.

Such an invitation would be styled as a new model of transparency for virtual weaponization programs and might then be extended to other countries. No decision to open up the history of the weapons program to international inspectors has yet been made, however, and with a new Social Democratic administration just taking office in Stockholm, such a move seems unlikely for now, officials said.

Larsson said the current nuclear weapons-related research in the Defense Ministry concerns planning for possible war by Swedish conventional forces on a nuclear battlefield; radiation safety for civil defense; technologies for monitoring the secret nuclear programs of other countries; and theoretical questions of nuclear weapon performance that could be useful in combating a terrorist or subnational group that might acquire a nuclear bomb.

To suggest that Sweden is clinging to a nuclear weapons option "is ridiculous," Larsson said. The number of scientists working on nuclear weapons issues in the Defense Ministry has declined steadily from its mid-1960s peak of about 350 to about 25 today, he said. Descriptions of the present research are published in Swedish budget documents. Moreover, "the real needle's eye for an industrialized, scientific-achieving nation who would want to make a nuclear weapon is the [fissile] material," which is all currently under international safeguards.

"The Swedish competence in this field is very, very small," Larsson said. "It's not even -- I was going to say a nucleus, but that's a bad joke. It would take several years to get together people and to train people to work on a [full weapons] program, given the political decision to do it. But even if we did that, we would still have to lay our hands on the material."

Yet to some analysts, the trouble with such explanations is that they rely too much on the good intentions of the country in question. In sophisticated countries with huge civilian nuclear industries such as Sweden's, the existing safeguards system on fissile materials is by no means foolproof, even by the IAEA's own assessment.

Political disincentives to building nuclear weapons have been and likely always will be a crucial aspect of the global nonproliferation regime. But some analysts now advocate backing up this basic system of political trust with much greater transparency and tougher technical safeguards on virtual weapons research and facilities.

"It might be nice to start thinking about how 'reliable' countries like Sweden handle this [nuclear weapons] competence, and to create a model" of transparency for others, said Wilhelm Agrell, a professor at the University of Lund who is writing a history of the Swedish nuclear weapons program based on recently declassified documents. "You don't know which nice, reliable country might become unreliable. No one can tell about the future."

Indeed, the history of Sweden's program shows that for all its public advocacy of total nuclear disarmament, its own security policy has in the past drawn it toward embracing the development of an offensive nuclear weapons option.

Swedish scientists began working on nuclear weapons problems as early as the 1940s and had developed a swelling, secret research program inside the Defense Ministry a decade later, according to the accounts of Prawitz, Larsson and Agrell. During this initial phase, as in many other countries at that time, the Swedes thought of nuclear weapons as merely the latest and most powerful evolution in conventional armaments that would play a central role on the battlefield of the future.

Although some Swedes involved argued during the 1950s that going nuclear would be immoral and impractical, a predominant military view at the time, recalled Prawitz, was: "Why should our boys fight with inferior weapons?"

That set the stage for a vigorous phase of research during the early and mid-1960s. The work depended on construction of plutonium-capable indigenous reactors such as the one at Agesta and included such fields as plutonium isotope separation, plutonium metallurgy, implosion techniques and weapon design, according to Prawitz, who was both a participant in the program and has carried out extensive interviews with his former colleagues.

Prawitz said the team never graduated to effective work on thermonuclear weapons and that its design work stopped short of concerted attempts to develop a deliverable fission warhead that would suit specific Swedish aircraft or war plans. The work was more preliminary -- concerned with shapes, implosion techniques and metallurgy -- and "was not a design in the engineering sense, to meet specific requirements and specifications as demanded by the military."

By the mid-1960s, the tide had begun to turn within the Swedish establishment against going fully nuclear, by the account of Prawitz, Larsson and other Swedish officials.

There were a number of factors, they said. Difficulties with commercial nuclear power development meant that the military could not rely on commercial plants for bomb material but would have to build its own expensive reactors, like the one at Agesta. The escalating nuclear arms race between Washington and Moscow meant nuclear weapons were coming to be seen less as practical instruments of war and more as strategic, political weapons.

The idea of using tactical nuclear weapons to defeat a conventional attack on Sweden by the Soviets seemed increasingly impractical, Prawitz said. And the Swedish defense establishment believed that to develop a strategic deterrent in the European context would require more than just one or two bombs, but maybe 40 or 50, he added. In a country of Sweden's size, such a program would have proved so expensive that conventional forces would have been seriously degraded, he said.

Moreover, as it became aware of the Swedish weapons program, the United States opened a secret channel of contacts aimed at encouraging Stockholm to forswear its nuclear option. U.S. nuclear weapons scientists from the Los Alamos and Livermore national laboratories undertook secret exchanges with their Swedish counterparts. NATO military planners drew up secret contingency plans to bring Sweden to the West's side if war erupted with the Warsaw Pact.

Swedish scientists involved assert that the exchanges with American weapons specialists did not include secret weapons design information or other classified data, apart perhaps from data on the kinds of warheads believed to be possessed by the Soviet Union. For the Americans, a central benefit of the exchanges was that they allowed U.S. scientists to keep track of any Swedish weaponization. For the Swedes, "these contacts helped us to gain some confidence in what we were doing," recalled Larsson.

In addition, by 1966, Sweden's secret military planning with NATO had helped to convince the Stockholm defense establishment that in the event of a European war, "the strategic interests of NATO will in the end result that they will come to our aid with nuclear weapons," said Agrell. In effect, Sweden came to believe it was tacitly under the NATO nuclear umbrella, Agrell said.

Swedish scientists date the formal decision not to build or deploy nuclear weapons to the mid- or late 1960s, although they acknowledge that some highly ambiguous research on issues such as plutonium metallurgy continued until the early 1970s. By then, however, Sweden was dismantling its plutonium laboratory and settling into a more archival, theoretical phase of nuclear weapons research that has continued to the present.

"The research program has never ended because, regardless of the plans to make a weapon, defense planning had to assume the contingency of a nuclear attack on Sweden," said Prawitz. "We had to assess the effects of a nuclear explosion, and so we needed some knowledge of how a nuclear bomb works."

In recent years, the Swedes have also studied new developments in nuclear weapons technology, such as nuclear weapons designed to disrupt communications with a giant electromagnetic pulse and space-based nuclear explosions contemplated in U.S. and Soviet antimissile defense programs, Prawitz and Larsson said.

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