Short 🧵: Data from the Chinese National Nuclear Safety Administration does seem to indicate a *slightly* elevated level of gamma radiation around the Taishan Nuclear Power Plant. These are the two monitoring stations closest (one on the left is at the plant).
As of yesterday, Taishan is at 153 nGy/h (153 nanograys per hour). That's above the level of other plants in the country.
The levels at both sites near Taishan NPP also seem to have been elevated since at least late May. This may be an indication that this has been going on for awhile, and is not an immediate emergency.
What's going on? According to this statement from @edfenergy, it seems like there is a build up of noble gases in the primary circuit. Noble gases are a bi-product of nuclear reactor operation, and also sometimes an indicator of a problem.
@edfenergy In particular, radioactive xenon (Xe-133) can be released from nuclear power plants during refueling or during accidents. Because Xe-133 is non-reactive, it can seep through pipes and buildings. If Xe-133 is building up in the reactor, it is very hard to contain.
But Xe-133 is not necessarily dangerous. It's non-reactive nature means that it isn't easily taken up by biological organisms. And it will disperse into the atmosphere.
The readings and statement show there's something going on. One poss is cracked or otherwise damaged fuel rods. That could lead to the excessive build-up of these noble gases during operation.
Talking with @CherylRofer this morning though, it sounds like this kind of problem, while... problematic... is not an emergency in-and-of-itself... curious what other nuclear tweeps think (@nuclearkatie wanna weigh in?)
@CherylRofer@nuclearkatie Further indications of whether this is serious may come from either @iaeaorg or @ctbto_alerts. China is required to report serious incidents to the IAEA. The CTBTO has noble gas monitoring stations throughout the region.
@ctbto_alerts@ferencdv I'd argue that's consistent with the Chinese NNSA readings at the top of this thread. The low levels seen around the plant probably wouldn't show up at the IMS stations (which are located much further away).
@ctbto_alerts@ferencdv PM UPDATE: Just piling on this thread, it seems those NNSA numbers at the top may be natural background (thanks to @maesetote again for pointing that out). So not an indication of a leak (though still possible).
EDF has said that there was a build up of Krypton and Xenon.
The Reuters story says that the issue is with "fuel rods and seals".
Not clear if that means the sealed endcaps of the fuel rods, or maybe the seals around control arms or some other mechanism in the core?
In any event, here's a nice IAEA summary of ALL THE THINGS that can go wrong with fuel rods:
But of course, this is just background. We have very few details about what's actually happened at Taishan 1. But just to emphasize again: the information we do have doesn't point to a big crisis right now.
FINAL UPDATE FOR NOW: @iaeaorg has responded that they are aware of reports and in touch with Chinese counterparts. As of now, the agency has "no indication that a radiological incident occurred."
• • •
Missing some Tweet in this thread? You can try to
force a refresh
And now @MAXAR's worldview satellite has supplied high-resolution imaging from earlier this very day, showing that there is still a ship stuck in the Suez Canal. #OSINTatWork
I would just like to point out that we now have confirmation of a ship stuck in the Suez Canal using multiple space-based sensors.
We also have imagery at different resolutions... And different nadir angles at different times of day... (credit: @Maxar@Airbus@planetlabs and @capellaspace for that previous tweet)
OMG, @rebeccalramirez just put me on to the CDC's "coping with COVID" coloring book for kids, and it's an exercise in anxiety.
Not sure I'll sleep tonight.
I'm the grown-up and I feel ALL OF THESE THINGS!
It's not your fault Timmy. It's happening. You're powerless to stop it. It is affecting every aspect of your life, and your loved ones may be in danger.
A lot of people are tweeting about how this new Pfizer vaccine finding has not been peer-reviewed. That's true, but it's also important to understand that academic peer-review is not the only way to be scientifically rigorous... 🧵
In the case of clinical trials, there are a number of methods to keep bias out of data. One is to "blind" the trial, so that both patients and those administering the vaccine don't know who gets the drug and who gets the placebo. This trial was fully blinded.
In other words, patients, scientists, clinicians, and even Pfizer executives had no idea who got the vaccine and who didn't. Only a small team of statisticians and medical monitors remained unblinded to keep the trial on track. They had no direct contact with the trial team.
First off, if you're in need of big picture view, check out this story featuring @brianweeden and @planet4589, which gives a nice summary of where things stand (an audio version also be on @npratc tonight!).
The airstrip literally appeared out of nowhere in 2016. It's on the edge of an old Chinese nuclear test site called Lop Nur (sometimes Lop Nor). And it's unusual for a couple of reasons....
First, the theory: It's known as "herd immunity". If enough people catch COVID-19 and recover, and if they are immune, then the entire population will be protected. Estimates vary widely, but somewhere between 50%-80% of a given pop would need to catch COVID for this to work.
Herd immunity is real, but historically only discussed in terms of vaccination campaigns.
For example, if 95% of a population is vaccinated against measles (very contagious) then a single case cannot spread into the community.
Wow. Wow. Wow. Reading through the criminal complaint against nanotechnology researcher Charles Lieber at Harvard (courtsey of @relucasz). This is nuts.
Lieber was offered $50,000 a month and $150K+ for collaborating with Wuhan University of Technology.
@relucasz The FBI alleges that this was part of China's Thousand Talents Program, to recruit Western researchers and steal intellectual property.
Lieber was offered cash (and apparently accepted).
@relucasz Wuhan University established the WUT-Harvard Joint Nano Key Laboratory based on the agreement with Lieber... But HARVARD never knew anything about it. When they found out about it in 2015, Lieber denied everything.