February 1, 2000

LETTERS

Assessing Nuclear Stockpiles

To the Editor:

Re "Russian Plutonium Research Raises Nuclear Questions" (Jan. 25):

As director of Los Alamos National Laboratory, I was disturbed by the comments of Dr. Matthew D. McKinzie about the Los Alamos analysis of Russian plutonium experiments.

First, no evidence from the Russian research or any other source suggests the American nuclear stockpile will age more rapidly than previously believed.

The Russian experiments on plutonium decomposition demonstrated reactions that take centuries to complete: roughly 11,000 years at room temperatures.

This is hardly evidence of "rapid aging." Dr. McKinzie argues that plutonium instability could cut the lifetimes of weapon cores significantly.

In fact, the Department of Energy and its laboratories have never found any such decomposition over the past 30 years of rigorous studies.

The United States' stockpile surveillance program examines any changes, however minute, that may occur in aging components.

In addition, enhanced surveillance programs focus on predicting the lifetimes of weapon components.

We have thoroughly analyzed the Russian work and continue to be confident in the stockpile's reliability.

The Russian findings do not change our expectations for the lifetimes of weapons cores.

The value of the Russian research to our fundamental understanding of plutonium behavior is significant.

We intend to continue our scientific studies to better understand the complex behavior of plutonium.

But what is most significant is how this and similar international scientific collaborations can enhance global nuclear security.

DR . JOHN C. BROWNE
Los Alamos, N.M.

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