Acid Chlorox reaction

[g_axelsson]

So by your logic, a head wind vs a tail wind would have no effect on how fast a 747 could climb to cruising altitude, assuming no other variables were involved. (ie. ground speed and throttle position)

Head wind or tail wind doesn't have any effect on the rise time as the airplane is moving relative to the moving air.

Radiation against a flow of materia means, that the radiation, wether it is particle or wave radiation, has to pass more atoms per time without hitting them. So, setting a flow of materia against the radiation is pretty the same as shielding with materia of a higher density.

I hope this simple image isn't made impossible to understand caused my bad germ-english :lol:

I just wonder, how fast must the flow be to take any effect, considering the speed of the radiation.

Any radiation is moving with relativistic speed, a flow of water is by all practical means stationary. To affect the radiation (beta, gamma, x-ray) you need to at least reach relativistic speed of the water before you see any effect.

Any radiation that can be stopped by a flush of cold water is short lived radionucleids carried up by the hot rising water.
If you flush the top of the water on the reactor with cold water you create a downward motion that exists before the heat flash, you also create some turbulence that will mix the hot and cold waters and reduce the temperature gradient, that will also slow down the speed of the hot water rising.

... I'm sorry, what was the question again? :mrgreen:

Göran

 

[solar_plasma]

makes sense, thanks

I already wondered, if any particles could be slow enough

now, getting the chance to ask a physician: for example beta particles exist at most different energies in eV, betas from H3 have such a small energy, typical instruments like FH40G do not measure them or at least not correct....where is that energy, is it the speed of the particle or is the particle itself some kind of stimulated or do we at this point have to understand it as a wave and its energy is given by the amplitude (since beta- is just a fast electron, which can behave like a wave)?

 

[bswartzwelder]

Traveller11,
You did a great job of explaining and I think I have a very good idea of what is happening and how. Perhaps, I oversimplified my thoughts on the equipment, but the combination of the materials required (to withstand the reaction of the leach) and the necessary design to withstand the 60 PSI make this something that would be very difficult for a hobbyist refiner to build. Personally, if I had one, I would like for there to be a significant safety margin built into the pressure retention part. I simply cannot imagine what an explosion with HCl and chlorine gas would be like. However, if there was no open space in the rotating cylinder, there would not be much of an explosion. A company I used to work for used many aluminum castings. Sometimes, one would come through where the metal was porous and couldn't be used. The technician would seal both ends of the cylindrical casting. Then, it would be ALMOST filled with water. Next, he would submerge it into a tank filled with water and pressurized it with compressed air. If the casting was porous, air bubbles would escape into the tank and rise as the casting was rotated. With most of the casting filled with water, there was very little room for the air. If there would have been a catastrophic failure, there wouldn't have been much air to release and explosively expand. Had one failed, it could have blown anywhere on the casting, so the failure point could have been on top, on a side, or on the bottom, but it was ALWAYS under water. The air pressure was most likely well below the failure pressure since they were only looking for pin hole leaks. Still, the idea of chlorine and HCL under pressure demands much respect.

In a way, I'm sorry about the reactor part of the thread. It isn't truly on topic, but I thought it was interesting and would be thought provoking. NOONE on this forum can honestly say they aren't interested in science and learning. If you look at the reactor, the core was cube (3 feet on a side) made up of fuel RODS approximately 1.375 inches in diameter and the Uranium was enriched to somewhere between 15 and 30% (sorry, I just can't remember the details). For the sake of argument, lets say the top of the reactor was 9 feet below the surface of the water. The byproducts, without a stream of water blowing them sideways had to travel a total of 9 feet vertically to the surface. Now, turn on the pump and blow a stream of water across the top of the reactor. Instead of travelling vertically, the heated water is travelling with both a vertical component AND a horizontal component. Again, I don't recall the actual numbers, but to make it easy, let's say the water jet was pushing from left to right with a velocity that will blow the water off to the side whereby once it reaches the surface, it has travelled 12 feet horizontally. Looking at these numbers, we have a triangle with a horizontal side of 12 feet and a vertical side of 9 feet. This is a classic 3-4-5 triangle. While the byproducts move 9 feet vertically, they are moving 12 feet horizontally. But the total distance travelled is neither 9 feet nor 12 feet, but 15 feet. The byproducts are moving along the hypotenuse of the triangle. It is still only 9 feet vertically, but with the 12 foot horizontal component, it works out to a total distance travelled is 15 feet. Nothing adds to the vertical speed. The pump merely adds a 12 foot horizontal component. This is an oversimplification, because we are talking about heat, velocity, distance, and the water medium. The true path is not a nice straight line. The water from the jet will spread out and the water rising from the core cools down as it intermixes with the rest of the water in the reactor due to turbulence. The actual numbers are not important, it's the idea or concept that I was trying to illustrate. A hot air balloon on a day with a crosswind might have been easier to visualize.

In the real world of power production, reactor cores are usually cubic and depending on power produced, some are 12 feet on a side. The fuel is formed into cylindrical pellets approximately 0.375 inches in diameter with both ends concave to allow for thermal expansion. (The enrichment of the uranium is very low. It used to be about 3% to 5%, but I think it is slightly higher now. The higher enrichment means you can run the reactor longer between refueling and therefore have less down time.) The fuel pellets are sealed in zirconium clad tubes. The cladding restricts the maximum temperature the reactor can reach safely. Get it too hot and the zirconium will come off. This is not a good thing. Then the tubes are arranged into bundles. Before they go into the reactor, you can actually walk right up to them without any danger. They are closely inspected visually before being loaded into the core. After they have been in the core and have produced energy, they become dangerous as the uranium has changed into other products. We had a discussion about this at work one day, and even the smartest people in the room weren't sure of the answer. The question was: "If you set a used fuel bundle in the center, of a football stadium on the 50 yard line, could you run fast enough to touch it before you died? Or, would your blood boil before you got to it? We could never really figure that one out. We knew the company wouldn't let us borrow a used fuel bundle, and no one would volunteer as a runner.

 

[bswartzwelder]

You can Google Pennsylvania State University Reactor, and there is a link to YouTube showing the reactor when it is being pulsed. It is only about 16 seconds long, but you can see how the radiation in the vicinity of the core decays off after the pulse.

 

[Traveller11]

Traveller11,
You did a great job of explaining and I think I have a very good idea of what is happening and how. Perhaps, I oversimplified my thoughts on the equipment, but the combination of the materials required (to withstand the reaction of the leach) and the necessary design to withstand the 60 PSI make this something that would be very difficult for a hobbyist refiner to build. Personally, if I had one, I would like for there to be a significant safety margin built into the pressure retention part. I simply cannot imagine what an explosion with HCl and chlorine gas would be like. However, if there was no open space in the rotating cylinder, there would not be much of an explosion. A company I used to work for used many aluminum castings. Sometimes, one would come through where the metal was porous and couldn't be used. The technician would seal both ends of the cylindrical casting. Then, it would be ALMOST filled with water. Next, he would submerge it into a tank filled with water and pressurized it with compressed air. If the casting was porous, air bubbles would escape into the tank and rise as the casting was rotated. With most of the casting filled with water, there was very little room for the air. If there would have been a catastrophic failure, there wouldn't have been much air to release and explosively expand. Had one failed, it could have blown anywhere on the casting, so the failure point could have been on top, on a side, or on the bottom, but it was ALWAYS under water. The air pressure was most likely well below the failure pressure since they were only looking for pin hole leaks. Still, the idea of chlorine and HCL under pressure demands much respect.

In a way, I'm sorry about the reactor part of the thread. It isn't truly on topic, but I thought it was interesting and would be thought provoking. NOONE on this forum can honestly say they aren't interested in science and learning. If you look at the reactor, the core was cube (3 feet on a side) made up of fuel RODS approximately 1.375 inches in diameter and the Uranium was enriched to somewhere between 15 and 30% (sorry, I just can't remember the details). For the sake of argument, lets say the top of the reactor was 9 feet below the surface of the water. The byproducts, without a stream of water blowing them sideways had to travel a total of 9 feet vertically to the surface. Now, turn on the pump and blow a stream of water across the top of the reactor. Instead of travelling vertically, the heated water is travelling with both a vertical component AND a horizontal component. Again, I don't recall the actual numbers, but to make it easy, let's say the water jet was pushing from left to right with a velocity that will blow the water off to the side whereby once it reaches the surface, it has travelled 12 feet horizontally. Looking at these numbers, we have a triangle with a horizontal side of 12 feet and a vertical side of 9 feet. This is a classic 3-4-5 triangle. While the byproducts move 9 feet vertically, they are moving 12 feet horizontally. But the total distance travelled is neither 9 feet nor 12 feet, but 15 feet. The byproducts are moving along the hypotenuse of the triangle. It is still only 9 feet vertically, but with the 12 foot horizontal component, it works out to a total distance travelled is 15 feet. Nothing adds to the vertical speed. The pump merely adds a 12 foot horizontal component. This is an oversimplification, because we are talking about heat, velocity, distance, and the water medium. The true path is not a nice straight line. The water from the jet will spread out and the water rising from the core cools down as it intermixes with the rest of the water in the reactor due to turbulence. The actual numbers are not important, it's the idea or concept that I was trying to illustrate. A hot air balloon on a day with a crosswind might have been easier to visualize.

In the real world of power production, reactor cores are usually cubic and depending on power produced, some are 12 feet on a side. The fuel is formed into cylindrical pellets approximately 0.375 inches in diameter with both ends concave to allow for thermal expansion. (The enrichment of the uranium is very low. It used to be about 3% to 5%, but I think it is slightly higher now. The higher enrichment means you can run the reactor longer between refueling and therefore have less down time.) The fuel pellets are sealed in zirconium clad tubes. The cladding restricts the maximum temperature the reactor can reach safely. Get it too hot and the zirconium will come off. This is not a good thing. Then the tubes are arranged into bundles. Before they go into the reactor, you can actually walk right up to them without any danger. They are closely inspected visually before being loaded into the core. After they have been in the core and have produced energy, they become dangerous as the uranium has changed into other products. We had a discussion about this at work one day, and even the smartest people in the room weren't sure of the answer. The question was: "If you set a used fuel bundle in the center, of a football stadium on the 50 yard line, could you run fast enough to touch it before you died? Or, would your blood boil before you got to it? We could never really figure that one out. We knew the company wouldn't let us borrow a used fuel bundle, and no one would volunteer as a runner.

The method I mentioned where the container is completely filled with solution, excluding all air, does not build internal pressures equal to the 60 psi the other method is charged with. The release of oxygen from the hypochlorous acid will more than likely stop at a few psi above atmospheric pressure. Think of a bottle of Coke with the cap on. Carbon dioxide dissolves in water at 25 psi. With the cap on the bottle, there are no bubbles visible in the Coke. However, when the cap is removed, with an audible "pop" as the 25 psi pressure in the neck of the bottle equalizes with atmospheric pressure (14.7 psi), we begin seeing bubbles as the CO2 volatizes and comes out of solution.

This is quite easy to test. If a person takes regular 6% bleach, or industrial strength 12% bleach, or makes up his own bleach from calcium hypochlorite powder and water up to, say, 20%, and then lowers the pH with acetic acid to 7-8, he will have created a solution of roughly 50/50 hypochlorite/hypochlorous acid. With 4" ABS pipe fittings and a short piece of 4" ABS pipe, a vertical container can be made with a cap on the bottom and a cap on the top with an opening in the centre of it for a smaller pipe fitting. Through this pipe fitting hole, add the solution until the container is about 95% full. Reduce the pipe fitting down with plastic bushings until a pressure gauge with a 1/4" base can be threaded in, making the chamber airtight. As the HOCl loses oxygen, it should reach a pressure where the loss of oxygen from the HOCl is stopped altogether and the pressure goes no higher. I am willing to bet it is not much above atmospheric.

 

[g_axelsson]

makes sense, thanks

I already wondered, if any particles could be slow enough

now, getting the chance to ask a physician: for example beta particles exist at most different energies in eV, betas from H3 have such a small energy, typical instruments like FH40G do not measure them or at least not correct....where is that energy, is it the speed of the particle or is the particle itself some kind of stimulated or do we at this point have to understand it as a wave and its energy is given by the amplitude (since beta- is just a fast electron, which can behave like a wave)?

Yes, the energy is contained in the speed of the particles released (alpha, beta, neutron, neutrinos, the nucleus... and so on) or in the wavelength of an electromagnetic wave (gamma rays). The energy released is mixed between all the parts in a decay so it can differ between the different parts.
For example in ³H the beta decay also releases a neutrino and it takes some of the energy away, the rest is shared between the nucleus, m₁, and the electron, m₂, conservation of impulse gives m₁v₁ = m₂v₂, as m₁ >> m₂ that leads to v₁ << v₂, the electron shoots off very fast and the nucleus just recoils slowly.

Let's look at the really low energy beta radiation from ³H. It has a mean energy of 5.7 keV, 1/2 to 1/3 of the energy of an electron in a CRT. In free air it would be stopped within 6 mm and even shorter in water ¹. But it's still traveling with 15% of the speed of light ².
To travel 6mm with 15% of C would take 0.13 nano seconds, I don't think the speed of the water would matter for the shielding effect. :mrgreen:

I guess that the answer on your question if there is radiation (moving particle) slow enough to be affected by the flow of the water is definitely no. Nothing energetic enough to penetrate the water is moving so fast the water seems to be stationary even with the most powerful pump.

In the case of running towards a radioactive pile on a football field the question is... it depends. But I would say that you could do it but you may die afterwards. There are three accidents I'm thinking of to support my claim.
- In the clean-up operation after Chernobyl part of the core was blown through the roof and landed on top of the nuclear reactor. Conscripts were bussed in to manually shovel the pieces back into the reactor hall. With heavy protection gear they could work for 40 seconds each. All survived the day but many died from cancer later on.³
- In Los Alamos there were an accident when some researchers accidentally made a piece of uranium supercritical. They discovered it when the chain reaction started and the air started to glow from the ionizing radiation. One of the researchers took the device apart and probably saved the life of the other persons. He died nine days later.⁴
- Also in Los Alamos, a tank with plutonium became critical and people could see a flash of light from the radiation flash. The operator, Cecil Kelley, was standing next to the tank and caught five times a lethal dose. He died 35 hours later.<sup>5

1</sup> http://en.wikipedia.org/wiki/Tritium
² http://www.ou.edu/research/electron/bmz5364/calc-kv.html
³ http://en.wikipedia.org/wiki/Chernobyl_disaster#Debris_removal
⁴ http://en.wikipedia.org/wiki/Criticality_accident#Incidents
⁵ http://en.wikipedia.org/wiki/Cecil_Kelley_criticality_accident

/Göran

 

[solar_plasma]

To travel 6mm with 15% of C would take 0.13 nano seconds, I don't think the speed of the water would matter for the shielding effect. :mrgreen:

I guess that the answer on your question if there is radiation (moving particle) slow enough to be affected by the flow of the water is definitely no. Nothing energetic enough to penetrate the water is moving so fast the water seems to be stationary even with the most powerful pump.

Thanks, I have just got an idea of using this to my pupils as a homework next time we talk radiation. :lol:

 

[bswartzwelder]

Thank you, Göran,

The very first accident involving a nuclear reactor was the SL-1 (Stationary Low Power Reactor #1) in Idaho. Three workers were performing some type of maintenance on the reactor, which was shut down at the time. One of the workers pulled out the "safety" control rod which kept the reactor safely shut down. As he did so, the water in the bottom of the reactor flashed to steam. The reaction was so fast (and so violent) that the water above the steam was forced upward and caused a "water hammer" effect. I'm not sure if the top of the reactor was blown off, but one of the workers bodies was not found for 3 days. It was found pinned to the roof of the building, having been impaled by the control rod.

In a nuclear reaction, the actual energy is released as the particles/waves from the reaction slow down. As it would take huge amounts of power to reach the speed of light (assuming it is possible), therefore, slowing down from near the speed of light releases tremendous amounts of energy. EVERY reaction that I can think of is energetic. Some require energy be added in the form of heat or electricity. Some give off energy such as mixing acids and bases (usually causes heat), or in nuclear processes by the slowing of the particles/waves involved.

Just to put things into some kind of perspective, the amount of energy released from a reaction can be measured in electron volts. If I remember correctly from my college days, the very most violent chemical reaction produces about 20 electron volts and less violent reactions produce less. This would be for a single molecule reacting. The very smallest nuclear reaction produces energy on the level of millions of electron volts for a single atom/molecule. I believe nuclear reactions in the range of billions of electron volts have also been recorded.