As I mentioned in the comments.
I don't think they are deep enough:
These shelters are buried 5 feet underground
Nor are they large enough ( not by a few orders of magnitude )
fit 10,000 people ... about 75,000 square feet
This is about
7.5ft^2 per person, to put that into context a room that is
10ftx10ft is 100 sq feet. So that is like a room that is 2ft by 2.5ft. And they have to live here for years?
Your probably going to need at least 2000 sq ft, or more per person. Because not all the space is living space. Some is hydro phonics, some is schools, power generation etc. Even if we cut that in half, that is still several orders of magnitude more then what you have.
A standard family of 4 in the US can do pretty good in a house that is around 1500-2000 sq feet. And consider, they don't spend every minute in their house. Sure there is some space that could be shared with the community, such as kitchens bathrooms etc. but given how much time they have to spend together they will be living on top of one another and that is a recipe for a lot of conflict.
People need space and a sense of privacy, or there will be a lot of conflict. Even with the lower number of
5000 people, we have about 15 sq ft each, which is about the size of a large bedroom.
You will need something like 12 sq ft, just for a bed, 2ft x 6ft, of course you could stack bunks and sleep in shifts, but would this work for 20 years, how about 40. So you will probably need about 250-500 sq ft, per person as a baseline minimum. at 400 sq ft, that is a room only 20ft by 20ft. So for 5000 people, that would be 2 million sq feet. You could easily double this, you could also get away with much less, but it depends on how long they are cupped up.
Generally the longer they have to spend confined, the more space you will want. This gives them some room for recreation etc.
My guess is for 5000 you would need at least 3 million sq feet, for that length of time. You could get away with a million but that's not going to leave much personal space once you factor in utility systems etc.
This is why I said you were off by orders of magnitude, which means your not even in the ballpark range.
Now I am not an engineer so I don't have some formula for this, but just ask yourself could you survive for 40 years with personal space that amounts to less then a 10ft by 10ft cube ( this would be 100 sq ft per person for 500,000 sq ft) and like I said, once you add in power plants, food, recreation area, utility areas etc will all cut into that space.
So In summery (just some general ideas):
I would say that the bare minimum would be 350,000 square feet, at this size you will probably have bunk rooms that have 3 bunks stacked. You may get away with 2, if you share bunks with shifts.
I would say with 500k you will still have, bunks 2 high, or have to share bunks in shifts
At 1 million you may have single bunks and not have to share, maybe single rooms
At 2 million, you may be able to have a small room/appartment for each person/family unit
At 3 million + You would have a small apartment with your own bathroom, kitchen etc.
Some of this depends how much room your power systems and other non-living space (like 20 cafeterias) are as these will all eat into personal living space.
The big issue is the amount of time, if they were saying for a few months having common bunk areas would be ok, it's better then being irradiated after all. But once you exceed a few years, people are going to need their own personal space. Even having them in rooms with bunks, after 40 years is going to be much like serving a life sentence in prison. That's ok if all you want to do is survive, but in such a tight high stress environment I can see fights and revolts breaking out.
If it was me, I would leave it vague. It's nice to have these numbers when figuring out the scale, but you can paint yourself into a corner by setting concrete values. You can just say it's a massive complex that spans several levels.
I would also have apartments, which would allow them to keep a family structure.
Have a level for sleeping, personal space, rec space. A level for food and production. A level for Command an control functions and weapons storage, training facilities etc. etc..