I remember this happening several times during the accident. At one point there was discussion that bubbled up in the media of completely abandoning the plant while meltdowns were in progress because they were worried about workers going over 250 mSv. Even though they did stay, there were critical actions that were repeatedly delayed that contributed to making the accident worse. Sometimes you have to say "your job is to keep people safe, and to do that you're going to have to take some risk."
You see this in the U.S. too with police officers. At Parkland and at the Pulse nightclub, police prioritized "officer safety" over public safety. People just want to follow a fixed rulebook about what is an acceptable risk, when in certain situations, an abnormally great threat justifies abnormal risks to avert it. This used to be understood intuitively.
You cannot expect the actual workers in radioactive disaster area to make such reckless decisions on their own. Such worker typically is not competent enough to decide that the directive of maximum acceptable risk should be overruled to make further work possible. The decision to expose workers to extraordinary risk should be made by the people in charge of the recovery effort, who should either be nuclear/biology experts or largely rely on what such experts tell them.
The Prime Minister calls the plant manager to ask why a valve hasn't been opened that's critical to avoiding a large radiation release. He's told that because they have no electrical power, it can't be opened electrically, and due to radiation, they haven't sent someone in to turn the valve manually. After a call from the Prime Minister of the country, the valve still wasn't turned for another 7.5 hours. From a resourcefulness standpoint, I question why there wasn't enough electrical power to actuate a valve, and from a human standpoint, why there wasn't enough bravery to send someone to do the essential job, certainly involving a far lower radiation dose than is accepted willingly by astronauts who go to the International Space Station, when the safety of their country is not on the line.
You see this in the U.S. too with police officers. At Parkland and at the Pulse nightclub, police prioritized "officer safety" over public safety. People just want to follow a fixed rulebook about what is an acceptable risk, when in certain situations, an abnormally great threat justifies abnormal risks to avert it. This used to be understood intuitively.