You need to read the laws in China where they require any chinese company or individual to hand over data to the chinese government on request, no exception, no lawsuit, period.
That is exactly how the world got into this situation in the first place. China covered it up and basically said nothing to see there. And the world believed in them and didn't put on guard against them. Until the disease spread to other countries and they no longer could cover it up. Then they say "hey look you have it too!"
If we can miniaturize nuclear reactors to the point that they can be drop-in replacements for batteries, then we can potentially run our electronics, appliances, machinery, vehicles standalone for decades without refuel/recharge.
Nuclear reactors can't generally be scaled down too far. The shielding requirements are about 4 ft of concrete on all sides, basically as a minimum. You can use pure-alpha decay radioactive isotopes as long lasting heat sources with a thermionic to make a 100W battery that last ~100 years. These are used in space probes like Voyager 1/2, Cassini, and Mars rovers like Curiosity and (soon) Perseverance. It used to also be used in pacemakers and soviet arctic light-houses.
The material is expensive (though it could be made much cheaper if a big market showed up), but more seriously it's a radiological hazard. Someone could disassemble such a thing and blow it up on a busy street with conventional explosives and cause a massive radiophobia-induced panic. You don't want to inhale a strong alpha-emitter.
I had heard these used Strontium(/Yttrium)-90 (β), but I might have been misinformed. Do you know where I can find more information about this subject?
Betavoltaic cells get outperformed by coin cells and RTGs by solar panels in most applications. There are some niche space applications, but not much else.
There has been critics in Asia on that the ex-Director General (2006-2017) of WHO, Margaret Chan, who was sponsored by China for the position, had been building up influence in the organization for China during her term so WHO would work in China's favour. Its effect is showing this time in how WHO handled this incident. Instead of taking a lead and look into the whether China had handled the pandemic properly upon its onset, WHO just parrot China's official stance, in fear of offending China.
I don't think you follow the news there. Just because you've only heard it yesterday doesn't make it new. The neighbouring countries have been on guard on the issue. There have been lots of news, leaks and complaints on this issue for the past several weeks. In fact the wet market in Wuhan had been officially "closed" for at least 3 weeks due to the disease. That means the pandemic has been spreading far longer than that.
Now they suddenly started to release updated numbers (due to pressure from their neighbouring countries) and you think it'd only "escalated in a week".
I have been following the issue since start of this month from Chinese media, where is the covering up?
Where is due to the pressure part? At first there had not been showing enough evidence of the virus's capacity to spread from human to human, which only confirmed recently because the medical staff gets infected and 2 cases in Guangdong, so the alert level is much lower than it is now.
You can blame the Chinese authority for not fully predicting the severity of the situation, but intentionally covering stuff up is a different accusation you better have strong evidence to support that.
The Chinese central government has already admitted their officials have been trying to cover it up. The president Xi had made it clear that he would "nail" the officials who are covering it up on the "pillar of shame" and those people will be "criminals of 10 thousand years".
