At first glance, the global nuclear landscape appears to be shrinking. Treaties have limited the number of nuclear-armed nations in the world and reduced the number of warheads America and Russia can possess. Summits and disarmament negotiations have filled headlines with reassuring statements suggesting humanity is reducing the nuclear threat.

Yet behind the diplomatic front hides a reality quite different. Weapons modernization projects, covert arms transfers, and clandestine research programs all prove that nuclear proliferation is alive and well, with much of it now hiding in plain sight. Nations have disguised weapons research as “civilian energy programs.” Uranium enrichment and plutonium reprocessing have been called “peaceful pursuits of nuclear power.”

International inspectors, bound by political constraints, see only what they are allowed to see as resources are secretly diverted toward illegal weapons construction.

The IAEA

The International Atomic Energy Agency (IAEA) is an independent arm of the United Nations established to promote the peaceful use of nuclear energy and to discourage its military use. But the Agency only has 275 field inspectors to cover 1,300 nuclear facilities worldwide  – a daunting task considering that many are massive, time-consuming, and physically demanding complexes to inspect.

That matters because plutonium is made in nuclear reactors during operation. The newly-formed plutonium is then chemically separated from spent reactor fuel by a procedure called reprocessing. And that matters because obtaining spent reactor fuel to reprocess for plutonium is a major obstacle to nuclear proliferation.

Since spent reactor fuel contains plutonium, extraordinary measures are taken to account for every kilogram of spent fuel. Preventing its diversion for unauthorized weapons use has been a major focus of international nonproliferation efforts for decades. No spent fuel, no plutonium.

But, despite having been effective in the past, this method of fighting illicit plutonium production has been compromised.

Driver Fuel / Target Core

There is a Washington, D.C. based organization called ISIS. The Institute for Science and International Security was founded by David Albright in 1993. Mr. Albright is an expert on nuclear proliferation who worked with the IAEA investigating Saddam Hussein’s nuclear weapons program in the 1980s. Today, he primarily works to expose nuclear threats through analysis of technical data and satellite imagery.

One common practice that ISIS has criticized is overreliance on controlling nuclear proliferation by limiting access to spent reactor fuel. Most spent fuel comes from Light Water Reactors (LWR) because over 80% of the world’s nuclear power plants are of that type.

But for technical reasons, LWRs require early shutdowns to extract the fuel if weapons-grade plutonium is desired. Aware of that, IAEA inspectors are extra vigilant during early shutdowns. But inspectors pay far less attention when reactors are in normal operation, knowing that plutonium cannot be obtained from a live reactor.

Which used to be true. But ISIS points out that even LWRs can produce weapons-grade plutonium without shutting down if a technique called Driver Fuel / Target Core is employed.

This method relies on the fact that, depending on size and configuration, over 10% of “free neutrons” escape reactor cores during operation. Plutonium is produced when free neutrons strike uranium atoms in reactor fuel and transform them into plutonium atoms. But the plutonium in the fuel cannot be extracted without shutting the reactor down to remove the fuel for reprocessing. However, Driver Fuel / Target Core technology circumvents the shutdown  requirement with “target blankets.”

Target Blankets

Target blankets are a generic term that may apply to anything made of natural or depleted metallic uranium for the purpose of secretly harvesting escaped neutrons. Free neutrons produce plutonium in uranium even outside a reactor core. Enriched uranium is illegal for private citizens to own in America without a license, but metallic uranium that has not been enriched is much easier to obtain and is far less expensive. 

The blankets themselves are easy to conceal. Metallic uranium is a tough, strong metal that may be fabricated into many shapes, such as sheet metal, steel plates, or angle irons and I-beams.

If shaped as thin metal “blankets,” metallic uranium may be disguised as sheet metal covering reactor core insulation. Thicker plates can be hidden under insulation, and metallic uranium can be disguised as structural steel supporting the reactor itself. Once painted, who’s to know?

The plutonium-bearing blankets are secretly removed after several months and replaced with fresh ones. They are higher quality and less radioactive than normal spent-fuel, but care must still be taken to shield biological life as the blankets are removed and transported to a hidden reprocessing facility for secretly extracting plutonium. 

Controlling and accounting for spent reactor fuel – a valuable mainstay of nuclear nonproliferation efforts – has lost some significance. The blanket method is not suitable for producing large amounts of plutonium, but the weapons-grade plutonium it does produce can be enough for a few nukes in a reasonable amount of time.

Reprocessing

Just one step remains to make weapons-grade plutonium once the blankets are removed. They must go through a procedure called reprocessing to extract the plutonium. Which of course requires a reprocessing plant – complex facilities that are normally quite expensive.

Figures vary considerably, but a new reprocessing plant can easily cost $10-20 billion. Few small nations or terrorist groups could afford the expense. But the chemistry involved is simple enough, and the price drops dramatically if some expensive safety measures are eliminated. Designs exist in open literature for reprocessing plants that cost less than $10 million and take about six months to build.

American scientists first revealed that possibility in a 1977 technical report describing a, “quick-and-dirty” reprocessing plant. Relatively inexpensive it may be, but it could still produce enough plutonium for two nuclear weapons its first week of operation. Given sufficient feedstock, it could produce enough for a bomb a day after that. The entire facility would be the size of a modest house buried underground for secrecy.

Implosion Technology

Implosion technology is not the obstacle it once was. This refers to the “implosion” method of forming a critical mass to make plutonium explode. It requires conventional explosives, specialized equipment for detonating the explosives with precision timing, and above all, plutonium to power the device.

The only nuclear weapon ever built that did not use implosion technology was the Hiroshima bomb. But the WWII scientists who invented implosion-type weapons spent billions of dollars and struggled mightily for three long years to make them work. Today, far more information than they ever knew possible is available to anyone on the internet.

Which leads to the observation that controlling access to plutonium is more critical than ever before. With details about implosion-type weapons now widely disseminated, the door to fabricating nukes is wide open once sufficient plutonium is obtained.

The Newest Easiest Way

It used to be that secretly enriching uranium was the easiest path to building illicit nuclear weapons. Uranium enriched to weapons-grade is suitable for use in gun-type nukes, which are easier to build than implosion-type nukes that use plutonium.

But enriching uranium still requires mining and refining uranium ore to produce metallic uranium. Then, a complex process at a costly conversion plant transforms the uranium metal into uranium hexafluoride gas (HEX). Finally, HEX must be transported to another complex and expensive facility where centrifuges enrich uranium to weapons-grade.

That’s a lot of expensive, complicated, and highly visible activity to hide. But any one of the approximately 360 Light Water Reactors in the world today can now be used to bypass all that and secretly produce weapons-grade plutonium with the Driver Fuel / Target core technique. Additional mining, refining, conversion, or enriching of uranium is not required.

A Cycle as Old as History

The proliferation issue is urgent. The wall crumbles if control of plutonium is lost. IAEA inspectors have a difficult job at best, and now must worry about new applications of Driver Fuel / Target Core technology.

Are metallic uranium plates hiding under that insulation? Is that really a steel angle-iron, or is it metallic uranium shaped like one? No sooner do inspectors gain an edge than bad guys find new ways to cheat. It’s a cycle as old as history, but the difference today involves the incredible stakes that nuclear weapons entail.

A Call to Action

At Our Planet Project Foundation, we believe the spread of nuclear weapons cannot be stopped if nuclear weapons still exist. Pressure to join the nuclear club can be strong, but will naturally evaporate if nuclear weapons are eliminated – the best, safest, and most reliable nonproliferation regime possible.

Big trouble is coming with nuclear weapons unless real changes are made, and made fast. If not, we may stop what we are doing someday soon and wonder –if only for a very brief moment – how did this ever happen?