Imagine, if you will, living somewhat close to a nuclear reactor—not right next door, but close enough—and then imagine that an accident at that reactor causes a large release of radioactive isotopes into the atmosphere. Certainly scary, but maybe less scary because you know your government has computer models that show where the nuclear fallout will blow and fall, and they explain that the amounts that will blow and fall on you are negligible.

Sure, you might think twice about that reassurance, but it is not like they are saying everything is OK. The government, after all, did evacuate some people based on their fallout models. . . so they are on top of it.

Then imagine five months later, after you’ve breathed the air, drank the water, and tramped dirt and snow in and around your home, the government reveals that even though they had the models, and even though they knew the amounts of radioactivity pouring into the atmosphere from the damaged nuclear plant, they didn’t input the known amounts into the fallout model, so that when the government was reassuring people, it was doing so based on a minimum measurable number used to build the model, and not the actual amounts then being released. So, now, you find that not only have you been living in a place that was well within a zone now littered with hazardous fallout, you find that many who were evacuated were moved directly into the path of that radioactive plume.

While you’re at it, imagine that you’ve been eating contaminated beef, because the government failed to stop the distribution of radioactive rice straw. And, also, imagine you’ve been drinking tea containing three times the allowable limit of radioactive cesium because the government didn’t think they needed to monitor tea that was grown over 100 miles from the failed reactor.

Imagine, too, that your children are safe because the amount of ionizing radiation they are exposed to is under the government’s annual limit. . . because the government just increased the allowable annual limit twenty-fold, from one millisievert to 20 mSv.

Of course, as I am sure you have already surmised, if you live in many parts of Northern Japan, you don’t have to imagine any of this—this is your everyday reality.

This rather terrifying reality really isn’t limited to Northern Japan, however. Yes, that region has suffered the worst of the triple play that was a massive earthquake, a tsunami, and reactor meltdowns, but the contaminated food has been found all over Japan (and now there is word that tuna is also showing evidence of contamination), and in Tokyo, outside the evacuation zone and even the worst of the newly revealed plume models, a rainstorm ten days after the earthquake increased levels of background radiation in the city, and they have remained high ever since.

A professor at Tokyo University recently made a speech before the Japanese Diet in which he compared levels of contamination and exposure from the Fukushima disaster to that from the atomic blast at Hiroshima—the current crisis being upwards of twenty times worse.

More troubling still—for the Japanese, and anyone, frankly, that shares a jet stream with them—the last couple of weeks have seen evidence of a fourth meltdown at the Fukushima Daiichi facility, and, perhaps even more disturbing, news of highly radioactive steam emerging from cracks in the ground around the reactor buildings. What makes that last point especially scary is that some believe this is evidence that the “corium” (the molten mess of fissile material that was once fuel rods inside of a reactor) has not only melted through the bottom of the containment vessel, but has started to burn through the concrete floor of the complex and is sinking toward the water table. (Images of Jane Fonda and Jack Lemon make this seem less serious to me, but you will hear others talk of this and reference The China Syndrome.) A constant leaking of a sort of radioactive smog is bad enough—it makes working on the cleanup go from ridiculously difficult to nearly impossible—but the bigger concern is an interaction between the corium and the groundwater that separates the hydrogen from the oxygen, causing a big explosion, sending more contaminants up into the atmosphere.

Such a scenario also sets up another imagination exercise: try to imagine just what effect this development will have on the already dubious plan to cover the breached reactor buildings with giant tarps. That’s one you will still have to imagine, because, as yet, there is no reported adjustment in the containment and cleanup plan from the Japanese government.

Of course, as terrible as this all is, it seems terribly removed from what should concern inhabitants of the mainland United States. After all, the US has not suffered this nuclear accident, it has no issues with leaking radioactive isotopes, America is a much larger and less densely populated country than Japan, and, after all, the dual disaster that caused the Fukushima reactors to meltdown is near to completely impossible for almost any of the reactors based in the US.

Except that none of that is true.

Though none have yet risen to the size and scope of the Fukushima disaster, the US has a long history of nuclear accidents. Some are of the instantaneous crisis variety, like Three Mile Island (to name only the most obvious of several), but many are of the slowly evolved, quietly revealed variety. For instance, just this week, health officials announced that radioactive tritium released from aging pipes at the Vermont Yankee nuclear facility had leached into the soil and has now been detected in the Connecticut River. In past years, strontium contamination had also been linked to the same plant. Vermont Yankee officials, now lobbying for a license renewal, have basically responded with “Pipes? What pipes?” and “Those are not our isotopes.”

And Vermont Yankee is just one of a long list of aging nuclear facilities built dangerously close to population centers. One third of Americans live within 50 miles of a nuclear reactor.

Feeling eerily similar to the Japanese response, the US government has met elevated readings of background radiation and radioactive isotopes triggered by the fallout from Fukushima with a decrease in the reporting of such data (and in some cases, an actual decrease in data collected). There is talk (behind closed doors, of course) of revising upward the acceptable amounts of radioactive contamination in certain foods. An AP report exposed a history of US government regulators working closely with the nuclear industry to weaken safety requirements and paper-over violations. And, even a series of relatively modest recommendations on how to enhance nuclear safety based on what has been observed in Japan is being slow-walked into non-implementation.

And maybe most disturbing of all, the very premise that is supposed to comfort us, that the meltdowns in Japan were the result of a catastrophic coincidence of events—an earthquake shutting off electricity to the plant, a tsunami knocking out the diesel back-up generators, thus leaving the facility with no way of powering the cooling systems—while already not wholly impossible in the United States, might turn out to be seriously flawed and overly optimistic. Evidence is beginning to emerge that some of the Fukushima meltdowns might have begun almost immediately after the earthquake, likely the result of multiple ruptures to the cooling system itself caused not by the tsunami, but by the tremor. In other words, even with full power to the plant, the cooling systems would have failed.

Reports right after the March earthquake in Japan found a disturbing number of US nuclear plants in active seismic zones, and found several near large population centers in the east to be even more vulnerable to earthquake damage than the two oft-cited California facilities. But here’s the clincher, those probabilities of whether a nuclear plant can survive an earthquake of a size likely to occur in a particular area are calculated on whether the tremor will damage the reactor core—those numbers do not factor in damage to the cooling system as the cause of a crisis.

How does the US government assess risk if a double whammy is not necessary? How does the NRC rate a facility if a breach of the containment vessel is not required to start a meltdown (or an explosion in an overheated spent fuel pool, for that matter)? As best I can tell, it doesn’t.

Imagination, as the song says, is funny. It makes a cloudy day sunny. It makes a bee think of honey. . . but it doesn’t cover-up reality when a real-world disaster continues to provide measurable data and cause considerable suffering. Governments on both sides of the Pacific might want to pretend that what we don’t know won’t hurt us, but the facts will prove that whether we know or not, the pain—both physical and economic—will be felt far and wide.

(A version of this post also appears at Firedoglake.)