Why didn't Chernobyl engineers don protective gear to inspect the reactor?

I watched the first episode of HBO’s Chernobyl miniseries, and was astonished to see that the engineers, after first noticing that something was wrong with the reactor core, went to investigate it without putting on ANY kind of protective gear. Not only that, but even after they realize that there’s been an explosion and that the plant is massively malfunctioning, they run around the various damaged rooms of the reactor exposing themselves to radioactive-contaminated water, smoke, and ash particles.

I thought maybe it was because they didn’t know how dangerous a radiation accident could be, but they HAD to know, right? This was the 80s, it wasn’t the dawn of the atomic era where they were figuring things out for the first time; they had decades of experience at this point.

Why would they take the risk of entering these highly hazardous environments without any form of radiation-resistant gear?

(Or is the show presenting an innacurate picture of how it went down?)

I don’t know the history of the accident or of Soviet era safety standards, but I note that in the movie there was a constant theme of denial and a refusal to accept that the core was destroyed. So there was no need for protective gear-even asking for it was criticized as implying that things were more serious than the managers wanted them to be. I don’t know but I am assuming that the movie tried to get their science and history right-and given what happened protective gear would not have helped anyway. It wasn’t so much that the reactor exploded and showered the area with highly radioactive uranium, it was that the main part of the core didn’t scatter-it was exposed to the air and was a solid mass of molten uranium. The gamma radiation from that mass must have been intense. Remember when they did get the radiation detectors out of the safe? One fried instantly and the second pegged at 200 Roentgens. Certainly lethal and lethal in minutes.

Everything I’ve read about it indicates that they were woefully unprepared and underequipped for an accident. The divers that were sent inside the reactor housing to drain the bubbler pool had regular wetsuits because there just wasn’t anything better available.

Water is an excellent radiation blocker, so I am not sure they needed much more than wet suits.

Swimming in highly radioactive coolant water isn’t so good, though.

The Tyvek suits you commonly see protect you from alpha radiation. Nothing, apart from lead (etc.) will protect you from gamma radiation.
Gamma radiation was the main cause for concern at Chernobyl. There are no lead suits. The people doing the clean-up knew they were fucked.

ETA: They did it anyway. “The lives of many…”

Gamma needs 5 cm or 2 inches of lead to be safely blocked.
Make a suit which has 2 inches of lead behind it. Good luck.

Just for giggles.

Average surface area if an adult male = 19,000 cm2.
Volume of 2cm thick lead body suit = 38,000 cm3
Density of lead = 11.34 g/cm3
Total weight of suit = 430,920 grams

I guess you could cut things down a lot by just shielding the torso and head but we’re still looking at maybe 200 kilos of lead…

ETA: Damn I misread inches for centimetres in AK84s post. So it’s 2.5 times heavier than I said.

Those lead aprons at my dentist’s office don’t do squat?

They are protecting againt low-energy X-rays. Even then, they probably don’t completely block them, but it’s better than nothing.

The power core to a nuclear reactor has a little more oomph behind it than the x-ray device at the dentist’s office.

No. Other relevant things to consider are strength of radiation, not all gammas are equal and x rays are relatively less energetic, distance from source, and duration of exposure, which in x rays, is momentary.

5-6 CM is sufficient to reduce the amount of exposure for even high energy rays to about background levels.

Actually, it’s safe, as long as you don’t try swimming to the bottom where the fuel rods are.

XKCD What If speaks.

You do understand that the reactor core exploded, right? The fuel rods melted into a pile on the reactor floor and radioactive particles from the uncontrolled chain reaction went literally everywhere. Workers outside the reactor housing were only supposed to be exposed to the radiation for 40 seconds total, while wearing protective suits.

And yet two of the three workers who did this are still alive and well, and the third went on to live another twenty years before dying of heart failure at 65. One of the living workers, Alexey Ananenko, still works in the nuclear industry.

People can survive a lot of things that aren’t good for them. What we do know is that the radiation was intense enough to turn the water acidic, so I stand by my earlier statement.

I thought it was because they knew they were fucked anyway. Did you see the look on those dude’s faces when the boss guy said: “Call in more people”?

The body is actually quite good at handling high doses of radiation delivered over short durations (even as long as hours).

Damage and repair occur.

Over longer exposure periods, even modest increases in radiation cause incredible amounts of damage, death. Short and fast strong radiation exposure is better than long exposure to increased radiation levels.

.

Permit me to recommend Chernobyl: History of A Tragedy by Serhii Plokhy (Penguin) which gives a very detailed account.

Yes, there was a lot of denial on the part of bureaucrats. Much less on the part of those in the reactor control room.

World of difference between the water in a spent fuel cooling pool, that is cleaned and its chemistry rigorously monitored, and the contaminated mess that those three firefighters had to wade through. AIUI, the area the firefighters swam had been contaminated with run off from cleanup efforts, so had no end of fine irradiated material and reactor material either dissolved or suspended within it or deposited on the bottom.

Not that spent pools are entirely innocuous. They can vary quite a bit, especially for things like Magnox fuel assemblies, depending on the fuel elements they contain and their susceptibility to varying corrosion modalities. Something I was unaware of.This 1982 survey from the IAEA has a decent compilation of compositions for spent fuel pools, starting at page 29.

Coolant within the primary coolant loop of a PWR is another substance that, while largely water to a very high degree of purity (along with other things to aid corrosion resistance and neutron moderation like boric acid salts and corrosion inhibitors.), nonetheless itself can be quite radioactive from neutron activation. Especially highly bio-available isotopes such as tritium. See, e.g., chapter 5 of "Radiochemistry in Nuclear Power Reactors (1996).

I think I’ve linked to this radiation dose calculator before. Play around yourself with various point sources of gamma, and how much shielding is required to attenuate the radiation flux to a desired level.