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Eleven miles southwest of
Oak Ridge on the Clinch River was the site of the planned K-25 Gaseous
Diffusion plant upon which so much hope had rested when it was
authorized in late 1942. Championed by the British and placed
first by the Lewis Committee, gaseous diffusion seemed to be based on
sound theory but had not yet produced any samples of enriched uranium
235.
At Oak Ridge, on a
relatively flat area of about 5,000 acres, site preparation for the
K-25 power plant began in June. Throughout the summer,
contractors contended with primitive roads as they shipped in the
materials needed to build what became the world's largest steam
electric plant. In September work began on the cascade building,
plans for which had changed dramatically since the spring. Now
there were to be fifty four-story buildings (2,000,000 square feet) in
a U-shape measuring a half-mile long by 1,000 feet wide.
Innovative foundation techniques were required to avoid setting
thousands of concrete piers to support load-bearing walls.
Since it was eleven miles
from the headquarters at Oak Ridge, the K-25 site developed into a
satellite town. Housing was supplied, as was a full array of
service facilities for the population that eventually reached
15,000. Dubbed "Happy Valley" by the inhabitants, the
town had housing similar to that in Oak Ridge, but, like headquarters,
it too experienced chronic shortages. Even with a contractor
camp with facilities for 2,000 workers nearby, half of the
construction force had to commute to the site daily.
In late summer of 1943 it
was decided that K-25 would play a lesser role than originally
intended. Instead of producing fully enriched uranium 235, the
new gaseous diffusion plant would provide around fifty-percent
enrichment for use as feeder material for Y-12. This would be
accomplished by eliminating the more troublesome upper part of the
cascade. Even this level of enrichment was not assured since a
suitable barrier for the diffusion process still did not exist.
The decision to downgrade K-25 was part of the larger decision to
double the capacity of Y-12 and fit with Groves' new strategy of
utilizing a combination of separation methods to produce enough
fissionable material for bombs as soon as possible.
There was no doubt in
Groves' mind that gaseous diffusion still had to be pursued
vigorously. Not only had major resources already been expended
on the program, but there was also the possibility that it might yet
prove successful. Y-12 was in trouble as 1944 began, and the
plutonium pile projects (X-10) were just getting underway. A
workable barrier design might put K-25 ahead in the race for the
bomb. Unfortunately, no one had been able to fabricate barrier
material of sufficient quality. The only alternative remaining
was to increase production enough to compensate for the low percentage
of barrier that met specifications. As Lawrence prepared to
throw everything he had into a thirty-beam source for Y-12, Groves
ordered a crash barrier program, hoping to prevent K-25 from standing
idle as the race for the bomb continued.
See:
'Enrichment of
Uranium" |