Megatons to Megawatts. The Russian-U.S. HEU Agreement

by Andreas M. Runge (




Historical Outline

Physics and Nuclear Engineering

Challenges the world faced


Lessons Learned

Additional Question




This blog entry is about the Russian-U.S. HEU-Agreement signed on February 18th 1993 and is based on a brief lecture which was presented on the way to the nuclear power plant museum ‘Zwentendorf’. It offers a brief introduction to the fueling of nuclear fission power plants by down-blending highly enriched uranium (HEU) from nuclear weapons. A historical point of view facilitates a better understanding of the burden nuclear states have had with these costly weapons.

The author‘s assumption:
The demand for cheap electrical energy will further reduce the world’s nuclear arsenal.


Historical Outline

During the Cold War, the U.S. and the USSR built up a massive arsenal of scary strategic and tactical nuclear weapons which would, in the case of war, turn the entire earth into a place of war, with massive fall-outs and global climate change. Paradoxically, the massive power of nuclear bombs rendered them useless as a weapon of choice. The global consequences would have affected the ‘sender’ even without nuclear counter-strikes.

During the Cold War, the nuclear superpowers knew they had to (re-)act rationally. Huge arsenals of nuclear weapons pointed at one another and could be triggered erroneously at any time. It retrospect, arms control is legitimate, because destroying the earth 42 times would have had the same effect as destroying life on our blue planet just once. There is no second earth. Looking at arms control from this perspective, the ‘Strategic Arms Limitation Talks/Treaty‘ (SALT) and continuous efforts for nuclear disarmament have always been economic for all parties.

When the Soviet Union broke into pieces, nuclear arsenals were suddenly in the possession of its newly found successor states, the Russian Federation, Ukraine, Kazakhstan and Belarus. For arms of the latter three, there was no longer a direct line between the Kremlin and the White House to prevent a misunderstanding. However, as these nuclear weapons were of no direct use to the government of the Ukraine, they were returned to Russia and the uranium was made available for down-blending.


Physics and Nuclear Engineering

Pictures of Japanese children who suffered health effects from the two nuclear bomb explosions oftentimes misleads people to believe that everything which involves nuclear physics, even research, is harmful. These pictures are genuinely heart-breaking and it is known that physicists felt guilty, as they claimed responsibility for their destructive powers.

There are many steps from the theory of physics to the engineering of a bomb. Historically, there are many people who had the possibility not to slaughter in wars. The difference between the slaughter with bushwhackers and the slaughter with automatically triggered nuclear bombs is the convenience to use them. Even a simple misunderstanding can cause their launch.

The imbalances of the Non-Proliferation Treaty (NPT) regime and the indisputable political and military capital of nuclear weapons influence countries like Pakistan, India, North Korea or Iran to become nuclear powers. The necessary knowledge about their exact engineering can only be learned by ‘reverse-engineering’, i.e. the process of analyzing a system to identify its components and function.

This is the reason nuclear weapons and sciences of their construction are dealt with confidentially. It is publicly known, that next to geometry and the moderator to slow down the neutrons, there is also a ‘critical mass’ of a fissile element like uranium isotope 235 (235U) needed to obtain a neutron density to start a sudden chain reaction which is fast enough to become critical before the initial device is blown apart.

Fuel for a uranium bomb is HEU, with a purity of at least 95%. Here, military use of nuclear energy already differ from its civil use in nuclear reactors. The fuel in nuclear plants is a blend with 4.4% of uranium isotope 235 (U 235) which cannot be used for nuclear weapons. In nature, there is a blend with the isotope 238 (U 238) and only 0,7% of uranium isotope 235 (U235). In both cases, freshly mined uranium needs to undertake an enrichment process, which means that the two isotopes are separated by mass. Isotopes of elements have different masses due to different amounts of neutrons. The principal chemistry should be almost the same since the amount of protons and electrons are identical. Russian engineers also made it possible to down-blend 95% 235U from warheads to 4.4% 235U for civil use in nuclear power plants.


Challenges the world faced

There were several challenges when the iron curtain fell:

  • The Russian Federation started its way into a market economy and faced a lot of corruption. Many, people who nowadays influence the Russian Federation as oligarchs, took advantage of the chaos. Taxation was difficult and there was no money to pay wages to engineers and scientists.
  • The Russian Federation was out of money and dependent on loans from the western countries.
  • The management of the nuclear arsenal of the collapsed Soviet Union was on the edge of getting out of control.
  • Safeguarding and maintaining the nuclear arsenal was very expensive for the Russian Federation. Consequently, the security of its nuclear facilities was not ensured at all times.
  • Russian nuclear workers and scientists were at risk of becoming unemployed and dictators like Saddam Hussein could potentially contract them.
  • Private initiatives to trade down-blended low enriched uranium (LEU) from the Russian Federation were too costly, due to U.S. tax protection provisions regulating its nuclear market.



A nuclear engineer from the Massachusetts institute of Technology (MIT), Thomas L. Neff, pushed for an agreement between Russia and the U.S. to partially open their markets. His plan was to use the HEU of Russian nuclear bombs to produce LEU fuel elements for U.S. nuclear power plants. The 13 billion U.S. dollar deal between the U.S. Enrichment Corporation (USEC) and TENEX on the Russian side stated the down-blending of 500 tons of HEU of 20000 bombs over the course of twenty years.

The deal was signed on February 18th 1993 and successfully completed by the Russian Federation in 2014. The U238 for the down-blending process was still mined in the U.S. so that the fuel elements could be used easily in U.S. plants. Half of all fuel elements used in U.S. power plants came from the Russian Federation as down-blended bomb HEU.


Lessons Learned

TENEX and USEC fulfilled the agreement. The nuclear community knows about its responsibility and helps concerned countries, even if it is bankrupt. Good ideas from civil scientists matter as the success story of Thomas Neff shows. For Neff’s disappointment, as he stated in an interview with New York Times published on January 28th 2014, he underestimated the amount of HEU the Russian federation possessed.


Additional Question

There is research to use the plutonium from nuclear weapons in the civil fuel cycle. Is there a possibility to use the plutonium from nuclear weapons in a MOX or thorium fuel cycle as well?



The Russian-U.S. HEU agreement turned out to be a win-win situation. Maintaining and safeguarding a nuclear arsenal is very expensive. By using the down-blended fuel elements in civil power plants the cost for disarmament, jobs for Russian nuclear workers and non-proliferation measures were covered.

My personal opinion about nuclear technology and nuclear weapons highlighted by a few arguments:

1. Nuclear weapons are a costly burden and of no use.

1.1. The probability of state failure is very high, as history shows. In case of unrests, a country’s administration loses power and the control of nuclear weapons diminishes. The probability of proliferation and irrational use of those weapons increases.

1.2. Therefore, all nuclear weapons should be dismantled. Down-blending finances disarmament.

2. Some people have the opinion that civil use of nuclear power is evil.

2.1. I am sure that the money from civil use of nuclear power is a good motor for disarmament as the fuel is needed for civil plants. By down-blending the HEU, the amount of weapon-usable material decreases. Also, the probability that one out of 40.000 bombs explodes by technical or human error is much higher than an error in a civil power plant.

2.2. Nevertheless, civil power plants should only be built in unpopulated areas. Power can be transported with High Voltage DC power lines to populated areas. It can also be converted into hydrogen for vehicle use.

2.3. Some state that there still is a problem with nuclear waste. In my opinion, the waste exists, no matter what we do. The pile has to be guarded and maintained. And the pile is poisonous, of course. But when we add more waste to the pile, the amount of danger emitting from it stays the same. The only problem is the risk during the transport to the location of storage. Even in the case of an accident however, the waste should be safe due to a good containment-design.

3. The International Atomic Energy Agency (IAEA) received a Nobel Price for its work.

3.1. Its slogan is ‘Atoms for Peace’, which focuses on the civil use of the knowledge of nuclear science. Peace is the absence of war. There is no need for war in case of prosperity, and the reasonable use of nuclear technology offers prosperity. By directing the scientific community in a peaceful direction, peace can also be ensured.

3.2. Modern life relies on nuclear sciences. Radio-chemistry, radio-medicine and radio biology are frowned upon and stigmatized. Yet, in the case of fighting diseases, everybody acknowledges their benefits. When everybody embraces his/her own peace and bans mechanisms of revenge, vice and evil, the world will become a better place through the distributed generation of peaceful thoughts.


Redirect to Essays overview

Redirect to beginning of this essay



[0] Nuclear Studies – Visit to Vienna with Nuclear Politic Group


[2], Thomas L. Neff, “A Grand Uranium Bargain”, The New York Times, 24.10.1991

[3], William J. Broad, “From Warheads to Cheap Energy”, 28.01.2014



[6], Bukharino, Hunt, “The U.S.-Russian HEU Agreement: Internal Safeguards to Prevent Division of HEU”, in Science & Global Security, 1994, Vol. 4, pp. 189-212

[7] , Pavlov, Rybachenkov, “HEU-LEU Project: A success story of Russian-U.S. Nuclear disarmament cooperation”, Center for Energy and Security Studies (personal opinion of the authors), 25.05.2013

[8], Diplomats of the Russian Federation and the U.S., “RUSSIAN-U.S. HEU AGREEMENT, 18.02.1993

All sources reviewed: 05.09.2014



Disclaimer: All rights reserved.


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