Continuity will become a challenge, and core Fukushima staff may have to be cycled out soon to due dose limit considerations
If you're not already familiar with the number, 250 milliSieverts is the absolute yearly dose limit for staff working emergency cases at the Fukushima Dai-ichi nuclear site. The percentage of workers who are quickly approaching this dose limit remains a mystery, but a look at Tepco's data helps us understand that a good amount of their early-responders (undoubtedly their most valuable staff) will easily hit their limits within a few months.
Based on the chart above, readings at the west gate (at a considerable distance from all the action) are slowly declining but are still at a hot 50 microSievert per hour. At 50μSv/hr (0.05mSv/hr), an employee at this location will rack up enough dose to hit their annual limit in just 208 days.
Where else can these guys hang out during idle time like after they've finished spraying kuricoat or after running a packbot mission? Sure as hell not at the site boundry - as of 4/15, it was registering a smokin 12 milliSievert/hr, taking any employee out of the system in just 21 hours time.
The shortest tenure in all the history of nuclear employment comes by way of reactor 3 and its vicinity, where a whopping 400milliSievert/hr dose rate will max you out in just 37.5 minutes. Break your leg at this location beyond earshot of anyone and you will face certain death after just 17.5 hours of exposure.
This is why Tepco currently has 700 people working the plant. The situation necessitates constant ojt/cross-training, because skilled workers in the trenches there can't possibly remain for sustainable periods of time. If you have nuclear work experience, are a notorious job-hopper and have absolutely no interest in having kids, this is the perfect job for you. No disrespect meant for Fukushima employees - that's just how it is.
This raises another essential point: If employees can work near the reactors for only minutes at a time, how can the existing cooling systems be repaired? That effort requires cleaning, repairs, welding, installation of new parts and most importantly - hours and hours of continuous work in high dose areas. Judging from the wreck of what's leftover from the explosions, it ain't gonna happen.