Russian Lies

The picture came from a news article published in the AAAS’s journal “Science”,  specifically the 9 December 2022 issue,  designated volume 678 issue 6624,  on page 1036.  The news article was titled “Hero City”,  and was about Kharkiv,  Ukraine,  being a former science center wanting to recover.  I literally photographed the page in the journal magazine. 

The picture shows what appears to be a bombardment missile that was apparently a dud,  embedded in the pavement near the Neutron Source Facility,  at the Kharkiv Institute of Science and Technology.  The missile would appear to be a tube-launched device with fold-out wrap-around fins. There would appear to be six of these fins,  each hinged three places to flip out,  all flipping-out in the same direction. 

The flip-out hinge line is canted with respect to the body axis,  as can be so very clearly seen with the fin more-or-less pointing toward the viewer,  in the center of the visible fin pattern.  All the fins cant the same way,  creating lift forces that sum up,  directed tangential to the missile body surface. 

Thus,  this is a spin-stabilized weapon,  which means in turn that it is otherwise unguided!  That kind of thing is not “targeted” at all,  it is a random area-destruction weapon,  typically launched en masse as an indiscriminate bombardment means.  I spent 20 years in aerospace defense engineering work,  so I really do know what I am talking about here.

“Unguided” makes a lie out of Russian claims they are carefully targeting their strikes in Ukraine! 

They also swore they were not going to invade,  right up to the day before they invaded.  And a bunch of other lies revealed publicly. 

The real takeaway here is that you cannot believe anything the Russians say:  not then,  not now,  and not in the future.  And that includes any possible “peace negotiations”. 

It seems apparent to me that the louder the Russian saber-rattling,  the closer they actually are to losing that war!  So,  why should Ukraine negotiate,  when they are actually winning?  Because of catastrophic damage to their infrastructure?  All that means is that our help is not yet enough. 

But,  the Russians also claimed they will not use nuclear weapons in Ukraine (despite their longstanding doctrine that they would do so in an attempt to avoid defeat on the battlefield). So be prepared for when (not “if”,  “when”) they do “go nuclear”!  The closer they get to defeat,  the more likely it becomes that they will use tactical nuclear weapons on Ukrainian cities!

If Russia loses,  Putin’s regime falls,  and he and all his cronies know it!  A Russia without Putin could be a friend.  Which is the best possible argument for doing everything we can to ensure Ukrainian victory.

References (which I wrote earlier on this topic):

#1. “How To Stop the Ukraine War”,  posted 27 November 2022

#2. “Nuclear War Warning”,  posted 12 September 2022 

How to Stop the Ukraine War

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This was also submitted as a potential article to the Waco “Trib” 11-24-2022,  and sent 11-28-2022 as a letter to the President of the United States.

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This article was used as a board of contributors item in the Waco "Trib" Sunday 12-4-2022.

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Whatever that was,  that fell in Poland and killed 2 civilians,  it came closer to starting direct war between Russia and NATO,  than anyone wants to admit in public.  There is some reason to believe the story that this was a Russian-made air defense missile fired by Ukraine that went astray,  and there is also some reason not to believe it.  Either way,  something like this is liable to start the war with NATO that goes out of control,  leading to nuclear war. 

I think pressuring Ukraine to negotiate with a Russia still occupying and destroying Ukraine,  is misguided at best,  and probably morally wrong!  Russia rarely negotiated in good faith as the Soviet Union,  and it is still behaving that same way under Putin today.  Nothing Putin (or any of his minions) says can be trusted,  that much we know for sure,  given the last 8 years' history regarding Ukraine.  But we do know they understand and fear the risks of war with NATO.  There’s a 7-decade history for that.

I would therefore recommend that we leverage those fears with a 3-fold ultimatum from NATO to Putin: 

(1) If a Russian-made weapons falls in a NATO country again,  regardless of whoever fired it,  then NATO is at war with you.  Such is a presumptive attack,  and response is thus an Article 5 thing.

(2) If any weapons hit that nuclear power plant in Ukraine,  regardless of who fired them,  then NATO is at war with you.  Radioactive fallout hitting NATO countries is also a presumptive attack,  and thus an Article 5 thing.

(3) If you continue (past a stated short-term date) committing war crimes in Ukraine by targeting civilians and civilian infrastructure,  deliberately or not,  then NATO is at war with you. 

Then move very large armies into place,  on NATO’s side of all the relevant borders,  to enforce it.  The notion is “Putin,  stop the war,  or be destroyed”.  It’s that ugly and risky,  and also that simple. 

I see no other way to stop this,  and stop it we must.  Putin’s war damages us all economically and politically,  and it is utterly catastrophic for Ukraine,  besides threatening nuclear destruction for us all. 

Do that ultimatum,  and I think you will see Putin stand down and withdraw from Ukraine,  rather than risk his personal destruction in a war that he knows he cannot win (nobody wins a nuclear war).  Withdrawal is then his only path to staying in power in Russia.  

Although,  his own people might then have something to say about that,  and good riddance,  too!  A Russia without Putin could be a good friend.

Otherwise,  Putin will continue destroying Ukraine and its people as if they were vermin,  his revenge for their leaving Russia after the fall of the Soviet Union.  That ugly description of deliberate genocide is precisely the real pattern of his Ukraine war so far!  Most of our diplomats and politicians won’t tell you that ugly little truth,  but I just did!  I’m old enough to recognize it when I see it.

And the longer this evil goes on,  the more likely this war will get out of control,  as Putin gets ever more desperate to avoid the humiliating defeats he has been suffering on the Ukrainian battlefield.  The more desperate he gets,  the more likely he will use tactical nuclear weapons against Ukrainian cities.

He will use them for his personal revenge,  they cannot conquer what his armies failed to conquer.  And yet we all know that event could well start the “big one”. 

Time is not on our side. 

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Update 12-8-2022:  Recent news reports indicate that Ukraine has found a way to strike military targets and support infrastructure hundreds of miles inside Russia.  They found a way to do this despite the fact that the US and NATO have not supplied strike weapons of sufficient range for that purpose.  Ukraine has been the west's proxy opposing Putin,  and deserves better:  it is past time to supply the strike weapons to bring Putin's war home in Russia.  The high risk of nuclear war is already there,  Putin has been rattling that saber for months.  I don't really see how more forcefully opposing him changes that risk,  which will not go away until Putin is dead and gone.  

End of May Update

My Mars mission study has been accepted for presentation at the Mars Society convention in Grapevine, Texas, August 4-7 this year. I will barely be back on my feet after knee surgery at that time, but I wouldn’t miss this meeting on a bet. The basic study was posted here 12-20-10, with an update posted 1-8-11, correcting an error I made in a Falcon-9 payload number.

All of the launcher and capsule data I used were obtained from the Spacex website for 2010. Sometime after January 2011, Spacex updated these data, showing a significant increase in payload capacity estimated for the Falcon-9-heavy, which is now supposed to fly for the first time out of Vandenburg late this year. That change just makes my design even more cost-effective, but I am not going to change my presentation because of it.

I did a little nontraditional thinking, dominated by crew safety, and came up with a tremendous science return for a lot less investment than anyone will likely believe. This is way more than “flag-and-footprints”. You never know what you can do until the blinders come off. It is going to be a lot of fun.

Latest news releases in AAAS’s peer-reviewed “Science” journal confirm everything I posted here about the nuclear plant disaster in Fukushima, Japan. You have to go inside the reactor building ruins before you find radiation too dangerous for adult humans, and then it’s just barely enough to cause prompt radiation sickness. The whole argument over risk to the Japanese public seems to center on the putative risks of very low-level exposures. With no evidence to support or deny a very slight risk of slightly-above-background-level exposures, it seems rather silly to worry much about it.

Now that the Mars mission study is done, and I will be off for a while with the knee, I can return to the question of ramjet-assisted launch. I’m pretty sure that horizontal takeoff with a two-stage vehicle is feasible with simple parallel-burn rocket and ramjet in a winged first stage. I’m pretty sure the staging velocity can be pushed to right at Mach 6 with a simple subsonic-combustion hydrocarbon-fueled ramjet. The upper stage rocket can be either winged or plain gravity-turn ballistic, as desired. To hit Mach 6 staging, a spike inlet will be required, which pushes practical takeover velocities to around Mach 1.5. Parallel-burn can be used right at staging to achieve path angle. I think the staging altitude is probably closer to 60,000 feet than 80,000 or 100,000 feet altitudes. That study needs a rerun with a resized engine and revised staging altitude. The earlier versions were posted here last year.

I don’t know yet whether ramjet assist is beneficial for a vertical-launch gravity-turn staged vehicle. But, if it is, it will be leaving the sensible, usable atmosphere closer to Mach 2 or 3 speeds than Mach 6. That’s a lower-speed ramjet design, most likely a simple normal-shock (pitot) inlet and a simple convergent-only nozzle. Takeover will likely be at slightly-subsonic to merely-transonic speeds. I have most of the guts of a sizing and performance code programmed, but it still does not quite work right in performance mode. Maybe I’ll have a chance to work on that while recuperating. Properly sized with an appropriate integral booster rocket, this kind of ramjet would be a strap-on staged off substantially earlier than the typical first stage burnout, in a two-stage vehicle. But it just might help.

Watch this space for future postings.

AAAS Confirms 3 Topics

The American Association for the Advancement of Science (AAAS) publishes a refereed journal called “Science”, in which new findings are publicized, duplicated, debated, and verified. Issue 6024 of volume 331, dated 25 March 2011, has some very interesting items. The 1 April 2011 issue (volume 332, issue 6025) has more confirmation of my articles, and more details than anything I have seen (so far) in the public media about the nuclear disaster in Japan.

Relative to “Oil Prices, Recessions, and the War” dated 4 February 2011:

In issue 6024 on page 1510 is a “News Focus” article “Peak Oil Production May Already Be Here”. The “Science” article has a plot of actual production history data which verifies that non-OPEC oil production has already peaked. Closer inspection of the same plot reveals that OPEC oil production is peaking, or has just about peaked.

The article also makes the point that “unconventional oil” (such as the Alberta tar sands), cannot make up the difference between energy demand and a peaking conventional oil supply. These are all points I made in the “exrocketman” article.

It feels very nice to be verified by items published in a refereed scientific journal.

Relative to Pre-Clovis Hunters in Texas on “exrocketman” dated 9 April 2011:

In issue 6024 on page 1512 is a “News Focus” article about the Buttermilk Creek archeological site, in Texas. The actual technical report on those findings is on page 1599 of the same issue. The scientific debate and verification now begins, but it looks like they have made a pretty good case for people in Texas long before the Clovis hunters.

The institutions making up this team include Texas A&M, Baylor University, and the University of Minnesota. We can be very proud of these institutions (especially our two local ones).

It’s mighty nice to see “local folk” make good.

Relative to 3 articles on “exrocketman” about the Japan nuclear plant disaster:

In issue 6024 on pages 1504-1507 are three “News Focus” articles about the Japanese nuclear plant disaster and associated cleanup difficulties.

Issue 6025 on pages 24-25 has a News Analysis article that has more confirmation of my articles, and more details than anything I have seen (so far) in the public media.

These are also closely related to three articles of mine on “exrocketman”: “On the Nuclear Crisis in Japan 3-15-11, “Follow-Up on the Japan Nuclear Crisis” 3-17-11, and “Radiation and Humans” 3-24-11.

These “Science” articles confirm what I have been saying on “exrocketman”: that comparisons to the Chernobyl disaster are overblown. There is no credible risk in the US no matter what happens in Japan, or what tiny amounts of radiation might be detected over here. The risks in Japan are only serious within a few miles of the plant.

The Fukushima Daiichi plant has 6 reactor units, as has been widely reported. It has 7 spent fuel rod pools, one for each reactor unit, and 1 more for the entire plant, which has not been widely reported. None of these spent fuel rod pools had any sort of reactor-like containment, in spite of containing quantities of spent fuel rod assemblies resembling reactor cores. These pools were housed in buildings of ordinary construction that were destroyed by the tsunami, as was all the electrical and cooling water infrastructure for the entire plant.

According to this latest article, it is the spent fuel rod pool for unit 4 that seems to be the true problem, radiologically. The core meltdowns reported earlier seem to have little to do with the spread of radiation beyond the plant. Apparently, this pool went dry and its load of zirconium alloy fuel rod casings overheated and caught fire in the air. The article even mentions “aerosolization” of fuel materials and fission products from burning fuel rod assemblies, exactly as I wrote.

According to the articles, the long half-life and rather dangerous cesium-137 contamination found within a few miles of the plant has to be coming from the unit 4 spent fuel rod pool, because it has to come from older (spent) fuel. The very short (8-day) half-life iodine-131 contamination found as far away as Tokyo’s water supply is far less a threat, and cannot be coming from fuel rod pool 4. The article suggests reactor unit 3 as a possible source.

Finally, the article discusses upgraded design criteria for earthquake and tsunami risks, exactly as I advocated in my third article. This is the first time I have seen this issue raised in any public news forum. It is long overdue, of course. But, at least someone is beginning to look.

Once again, it is nice to be verified by data published in a refereed journal.

This may be a blog, but I always try to tell the truth. To the very best of my ability, I do!

Radiation and Humans

Even after a week, the “Chicken Little / Sky Is Falling” reporting continues on the nuclear power plant accident in Japan. This has (1) completely overshadowed the true disaster (the tsunami which devastated a far larger area at least as thoroughly as the two atomic bombings in World War 2), and (2) has induced people to panic and do stupid things (like buying potassium iodide over here in the US).

There is too much ignorance about nuclear technology and radiation characteristics, out among the population in general, and the media reporters in particular. There is also too much ratings/money chasing sensationalism among the reporters. It dis-incentivizes telling the truth, and that’s a bad thing.

As the two previous articles indicate, not all nuclear radiation is the same. There are different intensity levels and different decay times. There is also a huge dilution effect that renders a potent local release very dilute and relatively inoffensive when spread across an ocean and around the world.

Long-Term Exposure Limits

Furthermore, not all human medical responses to radiation are the same. The steady slow accumulation of general “background” radiation exposure has one set of limits, for long-term late-in-life effects. Further, these limits have evolved substantially since nuclear age began. These are depicted in figure 1. The current numbers are 5000 milli-REMS (mR) for adults in any one year, with a lifetime accumulation limit of 1000 mREM x age in years. For minors (under age 18), the limit is 500 mR per year. For fetuses (and thus pregnant women), it is also 500mR per year, with the added restriction of no more than 50 mR in any one month. (See also units of measure note below.)

This 5000 mR annual limit for adults has evolved from earlier, higher limits set when we knew a lot less about the medical effects of radiation. During World War 2 and up to 1950, it was 25,000 mR per year. Between 1950 and 1957, this was reduced to 15,000 mR accumulated in any one year. The current level was set in 1957. The minor and fetus limits are newer. Today, astronauts get to absorb the old World War 2 limit in any one mission, which really means they shouldn’t do that more than once a year.

Steady Background Radiation

These exposure limits apply to general background (steady) exposure. That radiation has a natural component and a man-made component. The natural component includes natural radioactive materials in the Earth’s crust, plus cosmic rays from space. It is there all the time, and varies widely from location to location. The average for the entire Earth is in the neighborhood of 240 mR per year, and 300 in the US. Very locally at very few locations (such as uranium mines), it can be 10 or even 100 times more.

The man-made component to background radiation includes the well-known atomic weapons testing fallout, the leakage of radiation from nuclear plant accidents, and leaks from nuclear industry processes in general. When nuclear weapons were being tested above ground 1945-1963, there was a significant radioactive fallout contribution, the nuclear total peaking in 1963 at about 15 mR per year. Since atmospheric testing ceased in 1963, the nuclear total has dropped back to about 0.5 mR per year, practically insignificant compared to the natural background, and that includes accidents like Chernobyl.

It also includes the effects of accidents like Three Mile Island (which leaked almost nothing) and the current crisis in Japan (which has leaked something, but nothing like Chernobyl). This figure alone explains why it is silly to fear radiation exposure in the US, no matter what happens in Japan.

The man-made component of background radiation also includes what amounts to fallout from the burning of coal for electric power. Radioactive elements are included in coal deposits, and these are in both the gas plume and especially the fly ash. About 1/3 (around 120 mR per year) of the total background comes from coal plants. Most folks do not know or appreciate the fact that coal plants are a greater radiation hazard than all the nuclear bomb explosions or reactor accidents that ever were, combined. But you can clearly see it in figure 2.

The other exposure isn’t really background, because not all of us are exposed to it: medical imaging that uses radiation (X-ray or nuclear radiation). This can be up to around another 100 mR per year. This wasn’t as widespread decades ago, and a lot of these technologies didn’t even exist then, so in figure 2, I only show this on the modern exposure.



Figure 1 – Allowable Exposure Limits for Background Radiation



Figure 2 – Typical Background “Then and Now”

Short-Term High-Level Exposures

Nuclear bombs and reactor accidents release localized high doses of radiation that decay over time, as depicted in figure 3. These present risks of relatively prompt casualties, as well as enhanced risks of long-term injury. The human medical response to this type of incident is simply different. The arbitrarily-chosen standard is the dose accumulated in one week (168 hours). Table 1 is an abridged description of these effects. These take the form of a list of mR per hour rates, with the total dose absorbed (not shown) being the average hourly rate multiplied by 168 hours. (These weeklong accumulations are far higher than any yearly background exposure limits, even from World War 2.)

The peak hourly rate is crudely about twice the average hourly rate. Peak hourly rates are directly comparable to hourly dose rates reported or predicted for the fallout from nuclear weapon explosions. For bombs ranging from 200 kilotons to 1 megaton yield, “very close in” (a few miles) the typical peak dose rate is around 500,000 mR per hour within 1 or 2 hours of the blast. “Far away” (dozens to hundreds of miles) the peak dose rate is closer to 500 mR/hour, something like 9 to 14 hours after the blast. Decay to far more survivable levels happens in a week or three. Local leakage exposures from the worst nuclear reactor accidents are hundreds of times less intense than that from bombs.

One Numerical Example

Say the average hourly dose rate was 179 mR/ per hour, and this was received over one week. The total absorbed dose would be some 30,000 mR. Compare that to the World War 2 dose of maximum 25,000 mR in one year. It is 5 times the modern limit of 5000 mR per year for an adult, and 50 times the modern limit for a child. Close to a major event, you can accumulate more than a year’s dose very quickly. This stuff is very dangerous, make no mistake about that.



Figure 3 – The Nature of Decaying High-Level Short-Term Exposures

Table 1 – Medical Consequences of High-Level Short-Term Exposures (Abridged) (click on table to see a larger one, browser "back" returns you to article)



Conclusions Regarding the Dangers Posed by the Japanese Reactor Accident

The workers in the plant in Japan trying to rectify the situation are at very serious risk. Adults a few miles away are at only a little risk, but infants and fetuses are at some risk. Dozens to a hundred miles away from the leaking plant, there is almost no risk at all from airborne radiation. The only credible risks would be contaminated food or water, and they’re fairly small, excepting maybe for infants.

Quite frankly, the human-made background radiation from coal plants is the more serious risk.

A Note On Units of Measure
There are specific definitions for units of radiation known as the “Roentgen”, the “rad”, and the “REM”, but quite frankly, they are all equivalent. In the literature, they are all reported as the abbreviation “R”, reflecting that interchangeability. The milli-REM ( mR) used here is 1/1000 of a REM (or rad or Roentgen). Two other common units are the Sievert (Sv) and the Gray (Gy). Effectively, 1 Sievert is 100 R, and so also is 1 Gray. The Sievert is actually 100 REM while the Gray is 100 Rad, but effectively the REM and the rad are the same (just “R”).

A Roentgen is the energy of gamma radiation contained within 1 cc of air. A rad (radiation absorbed dose) is the radiation energy transferred to some mass of material, typically for us, a human. REM (Roentgen equivalent man) is the rad dose multiplied by a quality factor that models the biological impact. For gamma radiation and beta particle radiation, the quality factor is 1 (1 rad = 1 REM).

Follow-Up on the Japan Nuclear Crisis

The egregious “Chicken Little / The Sky Is Falling” reporting continues unabated over Japan’s nuclear plant crisis. I am getting very disgusted with all the fear-mongering-for-profit.

News media: please learn something about what you are talking about, before opening mouth and inserting foot. The run you have precipitated on anti-radiation iodine pills in the US is completely ridiculous, even insane.

It’s not that there aren’t serious risks at this plant, because there are. But, they have little to do with what gets splattered all over the evening news. Please refer to my previous posting on this subject (15 March 2011), and to figure 1 below.

Even if the reactor cores completely melt down, there is no risk of a Chernobyl-style intense-radiation event. Most, although maybe not all, the intensely-radioactive debris will remain within the outer (#3) containment, even if it is breached.

Breaching the #3 containment into the atmosphere to leak copious amounts of dangerous stuff is extremely unlikely in the extreme. This is for precisely the same reason that most of the fibrous “tire snot” sealing materials stay inside the tire, even after a blowout.

In any event, breaching that #3 outer containment is unlikely, because it is so very tough. This type of concrete and steel construction is pretty much the same as those concrete and steel structures still standing at ground zero of the Hiroshima and Nagasaki atom bomb explosions in 1945.

There, that should “calibrate” your gut feel for just how tough these structures really are.

Breaching the floor of the #3 containment, and releasing dangerous stuff into the earth and groundwater is more likely, but only in the event of a full core meltdown, which is still pretty unlikely, in spite of the severity of the disaster in Japan.

However, this is not atmospheric dispersion, and it stays more or less confined in a definite and geographically-small area. Radioactive fallout from the air is just not a risk more than a few miles from the plant, no matter what happens.

The real risk in this particular disaster is not the reactor and its containment structures, it is the spent fuel rod disposal ponds. These have little or no containment. If they go dry, and the spent fuel rods overheat and catch fire, that really is atmospheric dispersal of some very dangerous stuff.

That is the only thing anybody should be seriously worried about.

There are some lessons to be learned here. They are applicable to retrofits of existing nuclear plants, and to new plant designs. They are also nothing but plain old “horse sense”.

The Japanese plant was designed to withstand a Richter magnitude 8.2 earthquake, and quite successfully withstood magnitude 8.9. However, the geologic record (not the historical record) suggests that the Pacific Ring of Fire experiences quakes substantially above magnitude 9.

Not much can be done to “harden” existing plants. But, pick any number you want for design criteria for future plants. How about 9.5?

The problem in Japan wasn’t so much earthquake damage, it was the tsunami. Nobody planned for a 30-foot wave to sweep away the electrical grid and to disable all the back-up generators and water supplies. They haven’t seen a tsunami like that in Japan since 1700 AD.

Yet, the geologic record suggests that there actually have been far higher tsunami waves all around the Pacific, and in other oceans as well, including the Gulf of Mexico. Pick any number you want, but numbers on the order of 100 to 200 feet tall seem to have happened multiple times, all around the world in the geologic record. Just not within recorded history.

The other problem is the lack of multiple containment, around the spent fuel rod storage ponds. This is retro-fittable at every plant in the world today. It should be done as soon as is practical. It’s a safety thing, the “bottom line” is (and should always be) secondary to that consideration.




Figure 1 – Reactor Containments vs Spent Fuel Ponds

On the Nuclear Crisis in Japan

I am very displeased at the sensationalized, inaccurate reporting of this crisis in Japan, especially from the for-profit radio and television media. This is a disservice for the citizenry, and needs to stop. Now.

We all know that only bad news sells, and the more it is exaggerated, the more likely it is folks will sit through the commercials to hear the rest of the story. Besides that, the technical inaccuracies are quite egregious at times.

When there is a problem with a nuclear reactor, the appropriate expert to consult is a real nuclear engineer, not a nuclear physicist or a nuclear plant security expert. They did not study the actual engineering design of reactor systems and equipment, only the nuclear engineer did.

These exaggerations and inaccuracies feed into public fears, which in turn lets politicians take advantage of these fears, just to further their own careers. They do this instead of doing actual good for the people (which they swore to do, but so often fail).

This sensationalized, inaccurate reporting could put a damper on efforts toward increased US use of nuclear energy, at a time when we so desperately need more of it. Some truth about what is really happening in Japan could allay public fears and let our country get on with what it must do.

I personally am no nuclear engineer, but I am an experienced mechanical engineer. Here is some of what I do know about nuclear plants.

About Radiation

First, not all “nuclear radiation” is the same. There is more than one type of radiation, and more than one intensity level.

Some reactor fuel materials and their daughter products are quite intensely radioactive, and stay that way for long periods of time. These are generally solid materials, and in modern designs, not very flammable.

Other materials, such as core structures, containment vessels, and cooling water, can be “activated” into being radioactive materials by exposure to the nuclear radiation coming from the reactor core. These are also generally solid materials, and their radioactivity is initially far less intense, and decays far more quickly into insignificance.

The most innocuous of these are steam and air, harmless within minutes, and gaseous in form, so they cannot drop as “fallout” from the sky. See figure 1.



Figure 1 - Not All Radiation Is The Same

About Heat Production

Both the fission reaction and radioactive decay create heat within the active materials. Fission creates by far the most heat, but this ends immediately when the control rods are inserted to “kill” the fission reaction.

Radioactive decay produces less heat, but it is persistent for a time , until the radioactivity decays. Depending upon the material, this can be a very long time.

Reactor fuel and daughter products typically require many, many years to decay. This is in part why spent fuel rods are placed in pools of water: to keep them cool in spite of the heat produced by radioactive decay. The other part is that the water is a shield to absorb the radiation and protect the environment.

When a reactor is shut down by inserting the control rods, its core requires considerable cooling for a time measured in days to weeks, to offset the heat of radioactive decay. There is no fission heat being produced at all after shutdown.

Modern Reactor Designs

These typically have three very stout layers of containment: the fuel rod assembly tube, the reactor vessel itself, and a containment vessel; surrounding the reactor vessel and its closely-associated equipment. Some plants place this inside an ordinary building, others do not. See figure 2.



Figure 2 - Modern Reactor Designs Have 3 Layers of Containment

In these designs, none of the reactor fuel or core materials are flammable. The fuel is metal oxide, and is contained within a tube of exotic metal alloy. The fuel rod tube material actually melts before the fuel pellets themselves melt.

Fuel assemblies plus control rods, immersed in water, constitute the “reactor core” that is contained inside the reactor vessel. Water goes in and comes out as steam, because of heat produced in the core. This steam can be used (indirectly for radiation safety purposes) to generate electricity.

The first layer of containment is the fuel rod tube itself. Only if this gets hot enough to melt, are any of the still solid (or at worst molten) fuel and daughter products able to escape the tube.

The second layer of containment is the reactor vessel, which is a very stout steel item. It would take extreme temperatures and pressures to broach this vessel.

Pressure control in the reactor vessel is by venting, which releases the slightly radioactive steam and air, and little- to-none of the fuel or daughter product and fuel assembly tube materials. For post-shutdown cooling, water is pumped through the core in this vessel, whether that core is intact or not.

The third layer of containment is an extremely strong concrete and steel shell, built around the reactor and its associated equipment. These things are built to withstand impacting aircraft, explosive attack, tornadoes, and just about anything else but a direct hit with a large nuclear bomb.

If the reactor vessel does fail, the extremely dangerous mess is still contained within this shell. Again, pressure control is by venting the relatively innocuous radioactive steam and air. The truly dangerous stuff is nongaseous, and gets almost entirely contained within.

Many of the fuel assembly tubes, and maybe one of the reactor vessels, have broken in Japan because the plant’s core cooling ability was destroyed by the tsunami. None of the containment structures have failed, nor is it reasonable to think they ever will.

There cannot, and will not, be release of a disastrous quantity of the intensely-radioactive fuel and daughter products from the crisis in Japan. For pressure control, a very tiny amount of this material will be released, aerosolized along with the steam.

There will be a much larger release of the far-less-dangerous “activated” structural materials. Taken together, the danger of the released radiation is actually fairly low, and easily decontaminated by ordinary-but-prompt showers, and simple wash-downs of hardware.

Comparison to Chernobyl ?

This comparison is unreasonable fear-mongering. The reactor designs are completely different. The simple uncontained pile reactor at Chernobyl was a 1950’s Cold War legacy that should have been dismantled decades before it exploded . See Figure 3.

Today, no responsible or ethical engineer would design a reactor like that. It has no safety features or containment, and the operating characteristics are far less stable.

At Chernobyl, they lost control of the reactor, let it get too hot, and literally caught the core materials on fire. Both the graphite block structure and metallic reactor fuel were chemically flammable in air, and that is exactly what happened.

Without any containment at all, this fire produced enormous quantities of intensely radioactive smoke directly in the air. This smoke was composed of particles of graphite, reactor fuel, and daughter products, and exposure to it caused death within hours to weeks.

The proper comparison is to Three Mile Island, which did suffer a core meltdown inside the reactor vessel. However, at Three Mile Island, neither the reactor vessel nor the containment structure were breached. The only radiation released was the relatively innocuous and short-lived radioactive steam, and that at about the level of an ordinary chest X-ray to those exposed.



Figure 3 - The Antique and Unsafe Chernobyl Design

What Really Went Wrong In Japan
What went wrong in Japan had nothing to do with reactor core or containment design. It was an unanticipated wave size for the tsunami, which destroyed the post-shutdown cooling capabilities, specifically their electric power supplies. These were necessarily located outside the containment.

If we just design for taller tsunami waves, this problem with post-shutdown cooling capabilities never happens again. Simple as that.