March 30, 2012  

Comprehensive Nuclear Test Ban Treaty: Technical Issues for the U.S.

An important and much anticipated report on technical issues related to the Comprehensive Nuclear Test Ban Treaty (CTBT) was released today by the National Research Council (NRC), a private, nonprofit institution that provides expert advice on some of the most pressing challenges facing the nation and the world.  Read the NRC’s press release.

The NRC’s independent panel of experts writes that the United States is now in a better position than at any time in the past to maintain a safe and effective nuclear weapons stockpile without testing and to monitor clandestine nuclear testing abroad.

The report reviews and updates a 2002 study that examined the technical concerns raised about the CTBT.  The report Comprehensive Nuclear Test Ban Treaty: Technical Issues for the U.S. does not take a position on whether the U.S. should ratify the treaty.

The study was sponsored by Carnegie Corporation of New York the U.S. Department of Energy, the U.S. Department of State and the National Academy of Sciences (NAS). The NRC is the principal operating agency of the NAS.

The NRC’s independent panel of senior scientific and military experts were asked to assess:
• plans to maintain the safety and reliability of the U.S. nuclear stockpile without nuclear explosion testing;
• the U.S. capability to detect, locate, and identify nuclear explosions;
• commitments necessary to sustain the stockpile and the U.S. and international monitoring systems; and
• potential technical advances countries could achieve through evasive testing and unconstrained testing.

The report concludes that “the United States has the technical capabilities to maintain a safe, secure, and reliable stockpile of nuclear weapons into the foreseeable future without nuclear-explosion testing.”

The panel’s report also found that “the Administration, in concert with Congress, should formulate and implement a comprehensive plan that provides a clear vision and strategy for maintaining the nation’s nuclear deterrence capabilities and competencies, as recommended in the 2010 Nuclear Posture Review and related studies.”

To sustain these technical capabilities, the expert panel believes “will require action by the National Nuclear Security Administration (NNSA), with the support of others, on at least the following elements:
• a strong scientific and engineering base maintained through a continuing dynamic of experiments linked with analysis;
• a vigorous surveillance program;
• adequate ratio of performance margins to uncertainties;
• modernized production facilities; and
• a competent and capable workforce with a broad base of nuclear security expertise.

The panel’s detailed report also found that “[c]onstraints placed on nuclear-explosion testing by the monitoring capabilities of the IMS [International Monitoring System] and … U.S. NTM [national technical means of intelligence], will reduce the likelihood of successful clandestine nuclear-explosion testing, and inhibit the development of new types of strategic nuclear weapons.” 

The report finds that lower capability weapons developed by countries of different levels of nuclear sophistication “would not require the United States to return to testing in order to respond because it already has—or could produce—weapons of equal or greater capability based on its own nuclear-explosion test history. Thus, while such threats are of great concern, the United States would be able to respond to them as effectively whether or not the CTBT were in force.”

The study noted that an on-site inspection as allowed for under the treaty once it enters into force, “would have a high likelihood of detecting evidence of a nuclear explosion with a yield greater than 0.1 kilotons, provided that the event could be located with sufficient precision … and conducted without hindrance.” The panel noted that on-site inspection “constitutes a deterrent to treaty violation whether or not an inspection actually takes place ….” 

The study notes that “A technical need for a return to nuclear-explosion testing would be most plausible if the United States were to determine that adversarial nuclear activities required the development of weapon types not previously tested. In such a situation, the United States could invoke the supreme national interest clause and withdraw from the CTBT.”

In its conclusion, the report found that “[a]s long as the United States sustains its technical competency, and actively engages its nuclear scientists and other expert analysts in monitoring, assessing, and projecting possible adversarial activities, it will retain effective protection against technical surprises. This conclusion holds whether or not the United States accepts the formal constraints of the CTBT.”