April 16, 2001

The mission of the U.S. National Ignition Facility

Frank N. von Hippel
Professor of Public and International Affairs
Princeton University

I have been informed that a controversy has developed in Japan over the involvement of the US subsidiary of the HOYA company of Japan in supplying high-quality glass for the lasers of the U.S. laser-fusion facility called the National Ignition Facility. The U.S. nuclear weapons program is funding the construction of NIF at the Lawrence Livermore National Laboratory, one of two U.S. nuclear-weapon design laboratories.

Apparently a central point in the debate is whether the mission of NIF is to maintain and expand nuclear-weapons technology.

During 1993 and 1994, when the U.S. Government's decision to fund NIF was being made, I was involved in the discussions by virtue of my position as the Assistant Director for National Security of the White House Office of Science and Technology Policy. In 1995, I also served on the external review committee for the Department of Energy report, The National Ignition Facility and the Issue of Nonproliferation.

So I have both the knowledge and responsibility to explain the role of NIF in the U.S. "Stockpile Stewardship Program," the program by which the U.S. hopes to evaluate modifications in its nuclear weapons and train a new generation of U.S. weapon scientists without conducting test nuclear explosions.

Since 1994, the leaders of the U.S. nuclear-weapons design program have insisted that, in the absence of nuclear testing, NIF will be essential to their ability to maintain and enhance the laboratories' understanding of nuclear-weapons physics.

This is the principal mission of NIF. It cannot, for example, be used to confirm or improve the safety of U.S. nuclear weapons. Safety against accidental nuclear explosions requires that it not be possible for an accident to put the weapon's plutonium into a configuration where a fission chain reaction is possible. The relevant tests are done with chemical explosives. There is no need to create the conditions in a nuclear explosion. Even Livermore is not saying that NIF would be used for safety work.

Contrary to the claims from Livermore, NIF also cannot contribute in any direct way to maintaining confidence in the reliability of U.S. nuclear weapons. With or without nuclear test explosions, reliability is maintained by dismantling sample weapons, inspecting their components, and replacing parts that have deteriorated. Nuclear parts that cannot be tested without a nuclear explosion must be replaced with parts whose essential properties replicate those of the parts being replaced.

In 1994, the U.S. Department of Defense's "Nuclear Posture Review" imposed certain requirements on the Stockpile Stewardship Program. Subsequently, requests for funding of the NIF have been based in large part on Depart of Defense's requirement that the nuclear-weapons laboratories "[m]aintain [their] capability to design, fabricate, and certify new warheads" - but without nuclear tests.*

NIF is designed to achieve temperatures and pressures that approach those achieved in a nuclear explosion. Therefore, if the advanced nuclear-weapons codes now under development by the Livermore and Los Alamos National Laboratories are able to predict correctly the behavior of the small nuclear explosions to be ignited by the NIF, there will be more confidence in the correctness of their predictions for actual nuclear weapons.

I am among those who oppose changing nuclear weapons designs on the basis of computer calculations. Indeed, I worry that the weapons laboratories might use the new computer programs to justify proposals for new or redesigned weapons. Such proposals are already being put forward. If the military accepts some of these proposals -- but then insists on nuclear tests to verify the computer predictions -- it would destroy the test ban.

One last justification that is put forward for the NIF is that laser fusion might provide a new source of energy. However, it is generally understood that the glass lasers chosen by Livermore for NIF could not lead to economical fusion energy. The US energy program has been willing to spend only tens of millions of dollars on laser fusion - not the approximately ten billion that NIF and its operations would cost over twenty years.

Finally, I would like to express my admiration for the searching debate in Japan about the nature of Japan's relationship to the U.S. nuclear-weapons program. I hope that this article will contribute to a debate based on facts.