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Lop Nor
China Quietly Rebuilds Secretive Base for Nuclear Tests - New York Times
In the remote desert where China detonated its first atom bomb nearly 60 years ago, a drilling rig recently bored a deep vertical shaft that is estimated to plunge down at least a third of a mile.
It is the strongest evidence yet that Beijing is weighing whether to test a new generation of nuclear arms that could increase the lethality of its rapidly expanding missile force.
For years, U.S. government reports and independent experts have expressed vague concerns about the old base, Lop Nur. The reports point to possible preparations for year-round operations and a “lack of transparency.”
Now, however, waves of satellite images reveal that the military base has newly drilled boreholes — ideal for bottling up firestorms of deadly radiation from large nuclear blasts — as well as hundreds of other upgrades and expansions.
“All the evidence points to China making preparations that would let it resume nuclear tests,” said Tong Zhao, a nuclear expert at the Carnegie Endowment for International Peace….
https://threadreaderapp.com/thread/1...459531944.html
In the remote desert where China detonated its first atom bomb nearly 60 years ago, a drilling rig recently bored a deep vertical shaft that is estimated to plunge down at least a third of a mile.
It is the strongest evidence yet that Beijing is weighing whether to test a new generation of nuclear arms that could increase the lethality of its rapidly expanding missile force.
For years, U.S. government reports and independent experts have expressed vague concerns about the old base, Lop Nur. The reports point to possible preparations for year-round operations and a “lack of transparency.”
Now, however, waves of satellite images reveal that the military base has newly drilled boreholes — ideal for bottling up firestorms of deadly radiation from large nuclear blasts — as well as hundreds of other upgrades and expansions.
“All the evidence points to China making preparations that would let it resume nuclear tests,” said Tong Zhao, a nuclear expert at the Carnegie Endowment for International Peace….
https://threadreaderapp.com/thread/1...459531944.html
" a drilling rig recently bored a deep vertical shaft that is estimated to plunge down at least a third of a mile."
A third of a mile? that's not deep at 1742 ft.
The Mponeng Gold Mine in RSA is over 2.5 miles deep and oil & gas drillers routinely drill to over 17,000 ft = 3.2 miles
A third of a mile? that's not deep at 1742 ft.
The Mponeng Gold Mine in RSA is over 2.5 miles deep and oil & gas drillers routinely drill to over 17,000 ft = 3.2 miles
Ecce Homo! Loquitur...
Thread Starter
As the article states the depth is comparable to those drilled by the USA for their underground tests - and remember the shaft has to be wide enough to accommodate a a nuclear warhead and its associated test equipment.
Exactly. Offshore drilling starts with a tophole of around 36" diameter, but by the time it reaches the reservoir it may be only 7"
If there is anything to sample after an underground test, something has gone badly wrong. Much nfo these days comes from seismic analysis I think.
These holes have also been used for explosive events where no fission or fusion is intended but a set of hydro codes modelling the effects of the conventional explosive on the physics package or the effects of the primary on the secondary is being tested.
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It's not as simple as drilling a shaft and backfilling on top of the device, either; if you do that, it turns out that the explosion just shoots all your backfill back up the shaft. You need to excavate sideways from the bottom of the shaft too; there's quite a good writeup of the last US test, with a drawing of the shot cavity here: https://en.wikipedia.org/wiki/Cannikin
If you look carefully at that schematic it shows the bottom lateral to be a tunnel rather than a drilled hole. Note that the scale is sufficient for it to be named on the drawing as a "crawlway" for a human ! There are various scaled items in the drawing from which one can estimate the crawlway tunnel to be approxximately 24" tall and 36" wide. I'd guess the spherical cavity at the base of the milled and under-reamed casing to be approximately 6' diameter which figures as humans have to do some interesting contortions at that point, including ultimately with a device between their legs !. The casing itself looks to be approximately 30" or so, maybe 40" max at that point. I appreciate that was for a 5-megaton device, so the device itself was quite large. Manually excavating those shafts, then getting the test equipment into position, then getting the nuclear device into place itself - all by hand - must have been quite a job.
if you go to these links
https://web.archive.org/web/20131029...19401a_121.pdf (see p11 etc)
https://nuke.fas.org/guide/usa/nuclear/testing.htm
https://en.wikipedia.org/wiki/Underg...eapons_testing (see esp Pumbob Rainier)
Note that the offset nature of the Plumbob Rainier tunnelled test is what they are seeking to recreate in the subsequent drilled+lateral offset test configurations, so that the explosion collapes the wellbore before any surface ejection occurs. But this time using a vertical 30-48" bottom hole conductor and lateral shaft, rather than a horizontal tunnel and terminating spiral.
You can also infer from
https://en.wikipedia.org/wiki/Operat..._(nuclear_test)
that the horizontal tunnel was of sufficient dimensions to be a human crawlway.
Whether one can achieve equivalent geometries without using manual mining at the bottom of 30-48" shafts for modern (smaller) devices is an interesting issue. Modern (directional) drilling techniques, coil tubing, and all the jewelry that go into making multilateral completions might conceivably allow for a human-less shot hole construction. That would be ironic as it was the experimentation with civilian use of nuclear explosives that then indirectly begat the fracced shale oil & gas technologies that in turn would be used to create a modern nuclear test shot hole. Those might be (say) 7" bottom holes which a modern MIRV physics package ought to fit into.
Interesting technical challenge. One can see why the Chinese might want to get all their ducks lined up in a row to be sure everything works and they have the capabilities in sufficient volume well in advance. I read somewhere that the USA crammed over 100 tests into the final year or so as the CBT came into force. The Chinese might want to get quite a rapid salvo of tests done before suspending and yanking the curtain down again before other countries are able to squeeze in the validation tests they might want to get in.
Will the Nevada site soon sprout some more test shotholes, empty but waiting, ready for the US/UK (and I think, now France as well) test programme to run some quickies if the window opens briefly ?
China Quietly Rebuilds Secretive Base for Nuclear Tests - New York Times
In the remote desert where China detonated its first atom bomb nearly 60 years ago, a drilling rig recently bored a deep vertical shaft that is estimated to plunge down at least a third of a mile.
It is the strongest evidence yet that Beijing is weighing whether to test a new generation of nuclear arms that could increase the lethality of its rapidly expanding missile force.
For years, U.S. government reports and independent experts have expressed vague concerns about the old base, Lop Nur. The reports point to possible preparations for year-round operations and a “lack of transparency.”
Now, however, waves of satellite images reveal that the military base has newly drilled boreholes — ideal for bottling up firestorms of deadly radiation from large nuclear blasts — as well as hundreds of other upgrades and expansions.
“All the evidence points to China making preparations that would let it resume nuclear tests,” said Tong Zhao, a nuclear expert at the Carnegie Endowment for International Peace….
https://threadreaderapp.com/thread/1...459531944.html
In the remote desert where China detonated its first atom bomb nearly 60 years ago, a drilling rig recently bored a deep vertical shaft that is estimated to plunge down at least a third of a mile.
It is the strongest evidence yet that Beijing is weighing whether to test a new generation of nuclear arms that could increase the lethality of its rapidly expanding missile force.
For years, U.S. government reports and independent experts have expressed vague concerns about the old base, Lop Nur. The reports point to possible preparations for year-round operations and a “lack of transparency.”
Now, however, waves of satellite images reveal that the military base has newly drilled boreholes — ideal for bottling up firestorms of deadly radiation from large nuclear blasts — as well as hundreds of other upgrades and expansions.
“All the evidence points to China making preparations that would let it resume nuclear tests,” said Tong Zhao, a nuclear expert at the Carnegie Endowment for International Peace….
https://threadreaderapp.com/thread/1...459531944.html
"In a labyrinth of canyons he found, to his surprise, a large drilling rig being set up. .....That was July 2021.......
Unlike Lop Nur’s flat areas, the new zone’s rugged terrain provided good concealment for large gear. Despite this, Dr. Babiarz found a second drill site last year. It “was tucked deeper into the hilly terrain,” he said, and the rig’s support gear had been meticulously covered.
To atomic experts, the deep holes seemed to have been designed to contain large nuclear tests. “We never did subcritical tests in vertical shafts,” said Patrick Rowe, a former director of drilling operations at the Nevada test site. “It didn’t make sense because drilling the holes was so expensive.”
The surprise discovery of the drill rigs"
The way I read that they have observed two rigs on the satellite photos, not just two rig sites (pads). This is relevant because ordinarily two rigs are involved in any one such underground test. One rig drills the large diameter vertical shothole from which the device itself is offset & emplaced by humans underground*, with the monitoring package then set in the vertical shaft above, then the tamper. The other rig drills a second slender deviated well which ultimately intercepts the subsurface void left by the detonated device. (That void rises as it cools, rather like a lava lamp). The slender deviated well is used to sniff the void contents to obtain a chemical and nuclear fingerprint, that in turn gets added in to the other data to understand how well the test went. The point is that this second well should be mostly pre-drilled so that it can be extended immediately after the device is detonated , and then the samples can be as fresh as possible. A typical drill might progress at about (say) 50 ft/hr if going quite fast so you don't want to wait until after the detonation before drilling most of the hole. The deviated well will be (say) 3,000 ft long for (say) a 2,000 ft main shothole depth, after allowing for a safe pad horizontal displacement at surface. That implies a minimum 60-hour directional drilling task to get the second well in, if it is all done post-detonation and if it all goes smoothly. So they likely predrill the majority of the second hole in advance, so as to minimise time and risk. That in turn implies two rigs, each with somewhat different capabilities (though they could use on type of rig having both sets of capabilities).
So .... if they have two rigs they are likely figuring out how to do those deviated wells and the associated sampling programmes. So .... look for a series of primary and secondary holes, all ready to go. And all the assocciated testing gear (which might be either wireline, or coil tubing). Not something that they can ring up Schlumberger or Bakers to come and do for them. No wonder they have training facilities, they are - as is normal - being exceedingly thorough. Not to be underestimated.
* At least there used to be humans underground during the test set-up. Maybe things have moved on.
