Thomas B. Cochran

Gamma-Ray Measurements of a Soviet Cruise-Missile Warhead

A portable germanium detector was used to detect gamma-ray emissions from a nuclear warhead aboard the Soviet cruiser Slava. Measurements taken on the missile launch tube indicated the presence of uranium-235 and plutonium-239—the essential ingredients of nuclear weapons. With the use of this equipment, these isotopes probably could have been identified at a distance of 4 meters from the warhead. Such inspections do not reveal detailed information about the design of the warhead.

It’s Time to Give Up on Breeder Reactors

Since the dawn of the nuclear age, nuclear energy advocates have dreamed of a reactor that could produce more fuel than it used. More than 60 years and

History of the nuclear stockpile

100 billion later, that vision remains as far from reality as ever.

Fast Reactor Development in the United States

New details of the largely secret history of nuclear warhead production reveal that an astounding array of weapons has been created for every conceivable purpose by a gigantic, self-perpetuating system.

Nuclear Islands: International Leasing of Nuclear Fuel Cycle Sites to Provide Enduring Assurance of Peaceful Use

This article chronicles the rise and fall of fast-reactor research in the United States. Research on fast reactors began at the end of World War II and represented a large fraction of the total U.S. research effort on civilian nuclear energy until the early 1980s. The goal of most of this research was to develop a plutonium breeder reactor capable of producing more plutonium from U-238 than is consumed. But with the termination of the Clinch River Breeder Reactor project in 1983, fast reactor development in the United States essentially ended. Safety issues played a role in this end to the fast breeder reactor program, but more important reasons were nuclear proliferation concerns and a growing conviction that breeder reactors would not be needed or economically competitive with light water reactors for decades, if ever.

Proliferation and the nuclear disarmament process

Current International Atomic Energy Agency safeguards do not provide adequate protection against the diversion to military use of materials or technology from certain types of sensitive nuclear fuel cycle facilities. In view of highly enriched uraniums relatively greater ease of use as a nuclear explosive material than plutonium and the significant diseconomies of commercial spent fuel reprocessing, this article focuses on the need for improved international controls over uranium enrichment facilities as the proximate justification for creation of an International Nuclear Fuel Cycle Association (INFCA). In principle, the proposal is equally applicable to alleviating the proliferation concerns provoked by nuclear fuel reprocessing plants and other sensitive nuclear fuel cycle facilities. The INFCA would provide significantly increased nonproliferation assurance to its member states and the wider international community by holding long-term leasehold contracts to operate secure restricted zones containing such sensitive nuclear facilities.

Highly enriched uranium production for South African nuclear weapons

The greatest nuclear proliferation risk today arises from the lack of adequate physical protection, control and accounting of weapon usable materials in Russia. The most effective way to improve physical security and material accounting in Russia is through a cooperative effort to construct a comprehensive, non-discriminatory regime that ultimately would place all nuclear weapons and nuclear weapon usable materials under some form of multilateral monitoring. There is an urgent need for government action in states that now have significant programs involving the commercial use of nuclear weapon usable materials to defer further separation of plutonium until the global inventory of separated plutonium is significantly reduced and energy market conditions fully justify the added security risks of using plutonium in the civil fuel cycle.

A COMPENDIUM OF SELECTED RISKS OF AN LMFBR ECONOMY

We estimate that South Africa produced 735 ± 53 kilograms of the equivalent of 90 per‐cent‐highly enriched uranium (HEU). This amount, were it enriched to 80 to 90 percent, could be used to construct 12 Hiroshima‐type fission bombs. The South African government maintains it constructed only six such devices, and never intended to construct more than seven. The excess HEU was apparently less enriched than that desired by South Africa for its weapons, but probably still weapons‐usable. Implosion‐type devices were apparently being researched at the time the nuclear weapons program was dismantled in 1989. Had this effort continued, eventually South Africa would have been able to construct four times as many weapons from the same amount of fissile material. Because of a 15.6 percent uncertainty in the tails assay, the two standard deviation uncertainty in the amount of U‐235 in the HEU produced is 256 kilograms. It is in the interest of all parties to reduce this uncertainty.

Behind the Nuclear Curtain: Radioactive Waste Management in the Former Soviet Union

Publisher Summary This chapter presents a compendium of selected risks of a liquid metal fast breeder reactor (LMFBR) economy. The projections of LMFBR utilization in the United States vary widely. The Atomic Energy Commission (AEC) in the Proposed Final Environmental Statement on the IMFBR Program (IMFBR-PFES) projected for its base case 22,700 Gigawatt-years (Gw-yr) of IMFBR capacity between 1987 and 2020 plus an additional 25,600 Gw-yr committed in the 2020–2050 periods, for a grand total of 48,300 Gw-yr. Ten-thousand Gw-yr would be the equivalent of 500 IMFBRs, each 1000-Mw in size and each operating for 30 years at an average capacity factor of 67 percent.