I saw that a new giant cruise ship powered by methane gas has just entered service. The linked article talks only about the risk for climate change which might be caused by leaking gas, but I thought that it overlooks a much bigger risk. Methane is a lot more volatile and it is a lot more explosive than other fuels (Except hydrogen of course). I checked the technical details of the ship on Wikipedia and I saw that her generators at full power could provide almost 90MegaWatts and just for moving at full speed it might need up to 60MW.
I did a rough calculation. Assuming an average consumption of 50MW in one day it would consume 1.2GW*hour. Since it is not easy to find a fuelling station for a ship of this kind I assume that it will need to store fuel for at least 8/9 days of continuous operation which is more than 10GW and I guess this is a very conservative estimate.
According to this site 10GW*hour are equivalent to the destructive power of more than 8 Kilotons. Trouble is that this is not a gas storage facility kept at a safe distance from people. Counting passengers and crew at full load there could be almost ten thousands people sitting on that destructive power. So I am wondering through what kind of risk assessment the ship went through in order to be allowed to operate. What are the relevant international regulations on the subject?
Update:
Judging from the current answer, the comments and the votes it seems that my question is not clear. I'll try to explain it with different words.
Until now we had and we still have many small vehicles powered by gas on the public roads, but each with a limited quantity of gas. Then we had ships transporting LNG in enormous quantities with small specialised crews and far from other people. We also have storage facilities holding big quantities of gas with few specialised personnel, far from the other people.
This ship is the one of the first few instances where we put together big quantities of gas and ten thousand people in the same confined space. For the moment it is a rare case, but it is going to become a trend. I assume that from the engineering point of view it was designed with special requirements, but I wondered if there are also special legal requirements. My question is not whether they can or cannot enter a port. My question is how the construction and the beginning of the operations of this kind of ships is approved in the first place.