The Sum of All Fears.pdf - Delta Force

deuterium. Add another, and you get tritium. It has three times the atomic
weight of hydrogen, because of the additional neutrons. In simple terms,
neutrons are the stuff of atomic weapons. When you liberate them from their host
atoms, they radiate outward, bombarding other atomic nuclei, releasing more
neutrons. That causes a chain reaction, releasing vast amounts of energy.
Tritium is useful because the hydrogen atom is not supposed to contain any
neutrons at all, much less two of them. It is unstable, and tends to break down
at a fixed rate. The half-life of tritium is 12.3 years,' he explained. 'Thus if
you insert tritium in a fission device, the additional neutrons it adds to the
initial fission reaction accelerate or "boost" the fission in the plutonium or
uranium reaction mass by a factor of between five and forty, allowing a far more
efficient use of the heavy fission materials, like plutonium or enriched
uranium. Secondly, additional amounts of tritium placed in the proper location
nearby the fission device – called a "primary" in this case – begin a fusion
reaction. There are other ways of doing this, of course. The chemicals of choice
are lithium-deuteride and lithium-hydride, which is more stable, but tritium is
still extremely useful for certain weapons applications.'
'And how does one make tritium?'
'Essentially by placing large quantities of lithium-aluminum in a nuclear
reactor and allowing the thermal neutron flux – that's an engineering term for
the backand-forth traffic of the particles – to irradiate and transform lithium
to tritium by capture of some of the neutrons. It turns up as small, faceted
bubbles inside the metal. I believe that the Germans also manufactured tritium
at their Greifswald plant.'
'Why? What evidence do you have?'
'We analyzed the plutonium they sent us. Plutonium has two isotopes, plutonium
239 and 240. From the relative proportions, you can determine the neutron flux
in the reactor. The German sample has too little 240. Something was attenuating
the neutron flux. That something was probably – almost certainly – tritium.'
'You are certain of that?'
'The physics involved here are complex but straightforward. In fact you can in
many cases identify the plant that produced a plutonium sample by examining the
ratio of various materials. My team and I are quite certain of our conclusions.'
'Those plants were under international inspection, yes? Are there no controls on
the production of tritiurn?'
'The Germans managed to circumvent some of the plutonium inspections, and there
are no international controls on tritium at all. Even if there were such
controls, concealing tritium production would be child's play.'
Golovko swore under his breath. 'How much?'
The scientist shrugged. 'Impossible to say. The plant is being completely shut
down. We no longer have access to it.'
'Doesn't tritium have other uses?'
'Oh, yes. It's commercially very valuable. It's phosphorescent – glows in the
dark. People use it for watch dials, gunsights, instrument faces, all manner of
applications. It is commercially very valuable, on the order of fifty thousand
American dollars per gram.'
Golovko was surprised at himself for the digression. 'Back up for a moment,