26 June 1997

U.S. Tests Test Ban Treaty

Within the next week, the US Department of Energy (DOE) is expected to conduct the first in a series of underground subcritical nuclear weapons-related experiments at the Nevada test site.

The experiments are a part of the DOE's Science Based Stockpile Stewardship and Management Program (SBSSMP), designed to maintain the safety and reliability of the US nuclear stockpile under a "zero-yield" Comprehensive Test Ban Treaty (CTBT). The experiment - codenamed Rebound - is the first of six scheduled to take place in 1997-98. With an annual budget exceeding $4 billion and totalling $61 billion from 1997 to 2010, DOE is spending more annually on stewardship than while building new weapons during the Cold War.

The planned experiment, first announced in October 1995 and planned for June 1996, was postponed because, following internal and external pressure, officials realized the potentially negative impact on the CTBT negotiations. In May 1997, anti-nuclear groups filed a lawsuit seeking to halt the tests and other parts of the SBSSMP, and DOE decided to await the preliminary outcome before scheduling the tests. This week, the groups dropped the sections of the lawsuit on the experiments, and DOE now plans to proceed.

In these subcritical experiments, conventional high-explosives will blast plutonium pellets. Data gathered will be used to create computer models designed to predict the behavior of the material during full-scale explosions. The DOE claims that, in the absence of testing, it has to step up efforts to study the internal mechanisms of nuclear weapons in order to detect age-related changes and replace affected components.

According to an official from the Atomic Coordinating Office at the British Embassy in Washington, the UK is "not participating" in the first test. However, since the UK cooperates closely with the US on stockpile stewardship issues, and has staff at the three main DOE weapons labs, it is likely that British scientists will benefit from the information gathered from the experiments.

The DOE asserts that these experiments are designed not to produce a self-sustaining chain-reaction, and thus are permissible under the CTBT, signed by the US in September 1996. Other countries, however, have expressed concern that the size and nature of the experiments - conducted underground like full-scale nuclear tests - will be difficult to verify. Creating a strong verification regime was a major US focus during negotiations on the Treaty, which has yet to enter into force.

"With these experiments, the United States is undercutting the test ban treaty. These tests are unnecessary and will only damage the international nonproliferation regime. 'Subcritical' experiments not only imply continued reliance on nuclear weapons, encouraging other states to follow suit, but also can be used in attempts to design new nuclear weapons."said Stephen Young, senior analyst of the British American Security Information Council. 

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