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Can the U.S. Develop A Nuclear Bomb Without Ever Testing It? We’re About to Find Out.

In the 1960s, studies showed that throughout the U.S. and the world, children’s baby teeth contained 50 times the normal level of radioactive strontium-90, a byproduct of the warheads, increasing their risk of bone cancer. For these reasons, the United States moved to underground testing in 1963, where the explosions could be contained in deep holes and monitored with scientific instruments. Even then, underground tests led to contamination of soil and groundwater and vented radiation into the atmosphere, where it was often carried away on winds.

The new weapon should work just fine—in theory. But without live testing, scientists won’t know for sure.

Popular Mechanics, BY ADAM MANN MAR 21, 2024

One-foot-thick concrete doors lead to the central target chamber of the National Ignition Facility (NIF), a $3.5 billion research center dedicated to studying nuclear weapons. The mazelike facility is loud with the sound of whirring fans, banging equipment, and, on occasion, beeping signals. Each of the gigantic doors has been covered with concrete injected with boron, an element known for its ability to absorb high-energy neutrons that come blasting out of the chamber as a result of the explosive experiments taking place there………………….

The NIF is far more than just the world’s most expensive movie prop. The central target chamber is situated between two football-field-size buildings on the grounds of the Lawrence Livermore National Lab in Northern California. The enormous blue sphere contains the world’s largest and most powerful laser. Scientists can focus 192 individual ultraviolet laser beams onto targets no bigger than peppercorns. The targets implode with the force of a miniature nuclear blast. When this happens, for a fraction of a second, the target becomes the hottest place in the solar system, with temperatures exceeding 100 million degrees Fahrenheit and pressures 100 times denser than lead.

The only facility capable of conducting such experiments, the NIF has allowed scientists to pioneer fusion energy, investigate conditions in the bellies of stars, and answer questions about the complex physical processes that occur when a nuclear warhead goes off. That data has become all the more critical now that the Navy, Department of Defense, and the Deparment of Energy’s National Nuclear Security Administration (NNSA) are planning to build a new warhead, called the W93. (Nuclear weapons are named for the order in which they are conceived, making this the 93rd design considered by the United States.) This will be the first new nuclear weapon in more than thirty years—and it will be the first that scientists have ever built without the capability of testing it. That’s because since 1996, the United States has participated in a near-worldwide Comprehensive Test Ban Treaty that prohibits the detonation of a nuclear warhead anywhere in the world for military or scientific purposes.

Development of the W93 is expected to cost roughly $15 billion, and the warhead should be ready to deploy sometime in the next decade. The program was first announced in 2020 during the Trump Administration, and its preliminary design studies are due to be completed this October. Which means the United States has now entered into its first new nuclear weapons project since the end of the Cold War.

Officials feel assured that decades of research and simulations will allow them to produce the warhead without too much trouble. “We have learned so much about how the actual weapons work through these computer models and experiments,” says Frank Rose, the principal deputy administrator of the NNSA. “We have a high degree of confidence that we can design, build, and maintain this new W93 warhead without resorting to new explosive nuclear testing.”

But not everyone is convinced, especially given that things almost invariably work differently in reality than in models. “I find it enormously concerning,” says Geoff Wilson, a policy analyst with the Center for Arms Control and Non-Proliferation. “I’m sure that folks from the national laboratories will say, ‘Oh, we test these things all the time.’ And I’m sure that they are incredible simulations.” Yet military programs for things such as new fighter jets are often delayed and run over budget because engineers discover that their components did not work as they had originally been designed. So, Wilson says, “the question of testing is a real one.”………………………………………………………………………………………………..

The early live tests of nuclear weapons served several purposes. The 1945 Trinity test, the first ever conducted, was necessary for scientists to know that their new device would actually work as planned, and it also gave them their first look at the effects of a nuclear blast. When it went off, the blast released a force equivalent to 18,600 tons of dynamite, fusing sand in the New Mexico desert into glass and, according to observers, lighting up the sky “like the sun.”

The United States has conducted 1,053 subsequent nuclear tests, with various degrees of destruction. These were mainly done to gain a better understanding of different weapons designs, how powerful each would be, and whether nuclear weapons could be used in conjunction with soldiers on a battlefield.

Though most warheads were detonated in remote areas such as islands and deserts, live testing was still incredibly damaging to people and the environment. The 1954 Bravo test on Bikini Atoll, in the Marshall Islands, ended up being nearly three times larger than physicists had predicted, and the consequences were far-reaching. Radiation poisoning affected not only the crew of a Japanese fishing vessel near the fallout zone but also residents of Rongelap and Utirik, a pair of atolls 100 and 300 miles to the east, respectively. Such powerful tests left many islands uninhabitable and produced radioactive fallout that lingered in the atmosphere for long periods of time.

In the 1960s, studies showed that throughout the U.S. and the world, children’s baby teeth contained 50 times the normal level of radioactive strontium-90, a byproduct of the warheads, increasing their risk of bone cancer. For these reasons, the United States moved to underground testing in 1963, where the explosions could be contained in deep holes and monitored with scientific instruments. Even then, underground tests led to contamination of soil and groundwater and vented radiation into the atmosphere, where it was often carried away on winds………………………………………………..

Predicting how a nuclear warhead will perform when detonated requires understanding the material properties of plutonium, one of the strangest and most enigmatic elements on the periodic table. Plutonium is what is known as a fissile material, an element that is capable of undergoing reactions where atoms split apart, and it is used in the core of nuclear warheads. It is also an element so rare in nature that the amounts needed for an atomic bomb must be manufactured. Plutonium’s scarcity is also the reason we don’t know much about how it changes or degrades over time—information that’s vital to ensuring that our current atomic arsenal isn’t full of duds.

There is some debate as to whether the hollow plutonium cores of warheads that power the explosion, known as pits, need to be regularly switched out for newer pits. An independent assessment in 2007 from the scientific advisory group JASON concluded that the W76’s and W88’s plutonium cores should be good for at least a century. A 2012 study from Livermore backed up these findings, identifying no unexpected aging issues for 150 years, though it advocated for further research to understand the pit aging process……………………………….

Clearly, the goal of the Comprehensive Test Ban Treaty was to avoid the proliferation of nuclear weapons, and not just the testing of new ones. Plans to build a new nuclear weapon represents a deviation from the spirit of the treaty, says Lisbeth Gronlund, a nuclear arms-control expert and theoretical physicist at the Massachusetts Institute of Technology.

But the U.S. military believes it can and should be done. Nuclear weapons are the backbone of our military strategy, which rests on the concept of mutually assured destruction when it comes to conflict with other nuclear-armed adversaries……………………………………………………………….

The exact mechanisms the W93 will utilize are both a state secret and, at this stage, unknown, because the design details have yet to be decided. But the project will include a new aeroshell—the conical tip of a projectile in which a warhead is placed—called the Mark 7 (Mk7) that is meant to be less likely to detonate accidentally than the Navy’s current submarine-launched missiles. The chemical explosive that starts the process of the warhead’s explosion is intended to be less likely to detonate accidentally as well.  https://www.popularmechanics.com/military/weapons/a60255563/w93-nuclear-bomb/

March 21, 2024 - Posted by Christina Macpherson | Uncategorized