Breeder in the Desert: EBR-II

silent unchanging aloof this is the land of the central Idaho desert 100 years ago pioneers crossed this land forging westward on the trail it was here that the bad men of the Old West ambushed shipments of gold from the mines to the north even today plunder worth many thousands of dollars lies hidden forever in the silent reaches of the desert and the Lava Beds that cross it it was from these boots once active volcanoes in the prehistoric days of this land that lava spewed forth to cover a large part of central Idaho but its wealth of another kind that has made the Lava Beds famous here in 1949 the Atomic Energy Commission established the National reactor testing station some 875 square miles three-quarters the size of Rhode Island it serves as America's proving ground for nuclear power today caravans of buses and cars retrace the tracks of those covered wagons of yesterday bringing to the site scientists engineers and technicians The MITRE Hall Falls and some 30 other neighboring communities among many firsts these were the people first to light a bulb and later a town with atomic power these were the people who revolutionized naval power with the development of the nuclear submarine and today these are the people developing the atomic power plant of the future as they continue to answer the challenge of the Atomic Age [Music] Challenge is produced through a grant from the United States atomic energy Commission's Argonne National Laboratory this is the control console of the experimental breeder reactor number two here isolated on this Idaho desert is one of the most advanced and complex atomic power facilities in the world from this nerve center of EB r2 as it's called scientists and technicians monitor the intricate processes of nuclear fission and gather information that will guarantee a plentiful supply of atomic power with a nation in the world for centuries to come this reactor is different in many ways from the nuclear power plants that supply some of our homes today with electricity it's unique because it creates more atomic fuel than it uses dr. Harry Monson the project manager for EB r2 can tell us how this is possible this reactor actually does create more fuel than it uses Normand that is not to say however that it's a perpetual motion machine we still can't create something from nothing basically with EB r2 we are developing methods of extending our nuclear fuel reserves we do this by converting an inert material not usable as a fuel to plutonium which is a man-made nuclear fuel well suited for use in power reactors such as this one that sounds like a complicated process it is complicated and the equipment required is complicated yet if we are going to utilize all the nuclear fuel reserves our country possesses we're going to have to build many large plants of this general type to make plutonium the reason is this uranium as it occurs naturally as it is mine consists principally of a mixture of two kinds of atoms one is called uranium-235 the other uranium 238 less than 1% of the mixture is uranium-235 yet this small amount is used to supply almost all of our conventional atomic power the bulk of the mixture on the other hand is uranium 238 which is not usable as a fuel unless it is first converted to plutonium unless we convert 238 to plutonium in this way we will waste most of our nuclear fuel reserves would you say that using the 235 and not the rest is sort of like using the cream and throwing away the milk exactly this year reactor saves the uranium 238 by converting it to plutonium to a process called breeding by this process we create more fuel than we use and in so doing consume the uranium 238 which except for the benefit of this process would be practically worthless to us how is breeding accomplish that well let me show you here this is a model of a large tank we call the EPR - primary tank it is 26 feet across some 26 feet in height the tank is almost completely filled with a molten metal sodium submerged in the sodium near the bottom of the tank is the reactor at the center is the core or nuclear heart of the reactor within this core the neutrons which you'll recall our particles from the nucleus of the atom cause the fission reactions which yield the heat we use to produce power this reactor is so designed that the number of neutrons present is greater than the number required just to sustain the chain reaction and produce the desired heat we use these excess neutrons to convert uranium 238 to plutonium some of the uranium 238 is placed in the core of the reactor most of it is located in the so-called breeding blankets surrounding the core it all sounds fairly simple but I suppose it's far from it well the basic difference between this reactor and the conventional atomic power reactors lies in the speed of the neutrons employed this reactor uses very fast neutrons in designing a reactor to use such vast new however a number of difficult problems are encountered perhaps you'd like to see how some of these problems have been solved reactor plant permissive please Ross and Munson thank you we'll each have to carry a radiation dosimeter Norman these heavy doors looked as though they belong to something right you'll see doors like this at many of the atomic power plants our reactor and indeed the entire reactor building are totally enclosed within a heavy steel containment shell to get into that shell we have to pass through this double door airlock [Applause] you mentioned past neutrons what are they they're truly just that they're fast when the neutrons first are born in the fission process they are highly energetic they have great speed as they move about however they start to collide with various atoms of the reactor these could be atoms of fuel or of structural material or of course with each collision they lose a fraction of their energy they tend to slow down in this reactor we wish to keep the neutrons fast to enhance the breeding effect one of the principal reasons we use sodium as the court is that as neutrons go through sodium they do not lose their energy as quickly they don't slow down as rapidly as they do in the more ordinary foods such as water for example in fact we submerge the entire reactor and so the big primary tank the tank contains about 90,000 gallons or 320 ton incidentally it took ten railway tank cars to bring the needed sodium through the EBR Tuesday the bottom of the primary tank is about 40 feet below floor level in this building here in the sub-basement of the building you can see on the right the outer surface of the heavy concrete radiation shield which completely surrounds the primer the air ducts you say I used to carry cooling air to the shield the cooling is needed to remove the heat generated in the shield by absorption of nutri gamma rays the primary tank because of this radiation shield we cannot see any part of the primary tank itself and of course we can see nothing in sighted the necessary operations inside and to keep in touch with what is going on there many special mechanisms are used now we are approaching the operating floor above the operating floor you will be able to see the tops of some of the many mechanisms used for controlling the reactor for handling reactor fuel down inside the primary tank these are the control rod drive mechanisms they raise the control rods to start the reactor and shut it down over here is the top portion of one of the mechanisms used for changing fuel in the reactor a formidable task when again it is but they're able to control almost the entire operation from this computer console here on our left before attempting to describe the few changing procedure let's again look at this model of the primary tank we are standing here on the operating floor level directly underneath us is the primary tank the cover of the primary tank is particularly it has about 270 henna trations for holes for insertions of mechanisms the details of the cover are not visible on but we can look at a few photographs taken during construction the cover was made in two pans this is a top view of one of the halves during fabrication many of the holes for now see are called can't be seen you're two covers have been assembled this is the bottom of the cover again many of the holes through the cover can't be seen later each hole was fitted with the plug carrying a mechanism for an instrument with all the plugs in place the cover is completely gas tight note in particular this large central hole it is 12 feet in diameter and is fitted with a plug wing 120 tons is rotatable as well as gas-tight within that blog is a smaller rotating plug here are the almost completed primary tank is being lowered into inside the primary tank down near the bottom is the reactor the reactor 2 is fitted with the cover that cover can be raised and lowered to provide access to the reactor the reactor consists of a cluster thin assembly is containing fuel this is a model of such an assembly only the central portion of the assembly contains fewer uranium-235 or the till the upper section and the lower section both contain uranium 238 to be converted to plutonium insert and assembly with new fuel into the reactor the following procedure is followed the assembly first is loaded into the fuel loading machine some of the controls for which could be seen at the top of the machine the others on this console on the floor the machine then is brought to this end of its track and the assembly is lowered out of the fuel loading machine down through this transfer port into the primary tank at that time this mechanism we noted earlier takes the assembly and swings it to a position in the primary tank called the transfer report then the two rotating plugs rotate and equip er mounted on one of the plugs his position directly over the assembly the gripper is lowered and takes the assembly from the transfer fire after another rotation the assembly is lowered directly into the desired position in the reactor how Optima see changed the fuel well this depends upon the power level at which the reactor is operated his games at one time to three or for assemblies ahead of time fuel in the reactor as it is undergoing burn up by fishing fission products are retained accumulation of these fission products result in distortion and weakening of the fuel eventually they cause is removed it has been taken out of the primary tank however again if I may use the model assembly his place again storage basket there it stays until the decayed heat generate has subsided this takes about two finally the fuel is the storage basket taken out of the frame for reprocessing just building the equipment must have been nearly a superhuman task I should think hey breeder reactors a complex instrument that's a major understatement well practically all the mechanisms and specifically for this reactor to see more than that we will show you how all this fits together retrace our steps you might wonder why our control room and this turbine generator are located in a different building hundreds of feet from the reactor itself the reason is that we deliberately can find the reactor and all other intensely radioactive portions of the plant to one small area and then built a steel containment shell totally enclosing that area these portions of the plant do not involve any radioactivity and therefore we were able to place them in these much more convenient locations here in the control room I believe I can give you a general idea of how the entire plant functions the power cycle of EBI 2 consists of three heat transfer systems the primary secondary and steam electric systems this graphic panel illustrates the flow paths of these systems in this area the primary system is represented the major components are the primary tank outlined here the main heat exchanger to sodium pumps such as this one and the reactor itself in the core of the reactor an enormous amount of heat is generated within a very small volume if that heat were not removed as rapidly as generated the reactor would melt to remove the heat we pumped some 9,000 gallons of sodium through the reactor every minute what happened to the pump suddenly failed the reactor would shut itself down immediately automatically in the adjacent area of the panel the secondary system is shown the sodium flows from the secondary pump through the main heat exchanger picking up from the primary system the heat it had picked up from the reactor and then flows over to the steam generator in the sodium boiler plant but a fantastic arrangement of it is basically it's just another series of heat exchangers however these exchangers are of highly refined very sophisticated design in these units the heat is transferred from the secondary system sodium to water to generate steam at a temperature of about eight hundred and forty degrees Fahrenheit and a pressure of one thousand three hundred pounds per square inch the steam then flows to the turbine generator located just outside the control room the flow paths of the steam system are shown in this portion of the graphic panel there are too many small flow paths for us to be able to follow them through this control room is such an amazingly complicated looking place is the operation as complicated as it looks it is relatively complex we do use a great deal of automation however to aid us as one example we even use a computer to read many of our control instruments for us and automatic typewriters such as this one to record the information nevertheless it is necessary for our operators to maintain a very close watch over a number of the more important instruments so they take a closer look at some of those instruments yes let's start over here our control panel is divided into sections each section corresponds to a particular part of the system in this section monitors keep track of the radioactivity levels throughout the plant you'll find each section has its own alarm system to tell the operators when something is amiss when that buzzer sounded this light went on indicating that the shield cooling system flow rate was too low the operator acknowledged the alarm by pressing the silencing button he'll now investigate the cause of the low flow the next section relates to the secondary system here various temperatures pressures and flow rates of that system are monitored this section pertains to the primary system here are hundreds of temperatures liquid levels pump speeds and the like are indicated and recorded on these instruments now we come to the nuclear panel here the neutronics of the reactor are monitored this is the panel that the operators watch most closely what are these does it look like giant temperature gauges these are control rod position indicators Norman there are 12 control rods and to safety rods the height of the tape indicates the amount by which the particular rod has been inserted in the reactor in this case four control rod number eight the rod is in some 11 inches the digital indicator underneath show is the right to be in precisely 11 and 400 inches these instruments record the Neutron flux levels in the reactor next comes the large graphic panel at which we looked earlier however and beyond it are several panel sections which relate to the turbine generator and the electrical power distribution system these are quite conventional they're about the same as you'd see in any steam electric power plant how much elected party you made about twenty million watts Norman that's more than enough to power a city of say twenty five thousand people as you know however the production of power is not our prime objective in EB r2 we are collecting data and information with which we can design very large power breeder reactors to power our large cities in the future I see one aspect of this system is perhaps more revolutionary than anything we've seen so far this reactor is the first in the world to have its own fuel processing plant attached to it this plant is completely integrated it's tied right into the reactive system we have time for just a very brief look at it [Music] when I used fuel assembly is removed from the primary tank that is taken out of the reactor plant through an underground airlock into this building the assembly is transported in a heavy shielded container called the coffin here we see a dolly moving the coffin up to this open hatch the coffin next will be lowered through the hatch to another dolly which will move it into position underneath the Aircel directly ahead of us a manipulator will pull the assembly out of the coffin up into the air sell a remotely operated machine then we'll disassemble the unit to obtain the 91 fuel elements it contains this is what the fuel elements look like Norman all 91 elements then are passed through an air light into the argon cell here the fuel elements are entering the argon so which has an atmosphere of pure argon to minimize corrosion of the fuel alloy during reprocessing at this first station of the argon cell a remotely operated machine is used to strip this thin stainless steel jacket off the fuel alloy and break the fuel alloy into small pieces in the next step the fission products are removed from the fuel alloy by a process called milk refining finding in this process the pieces of Li are placed in a crucible and melted at the high temperature employed some of the efficient products I driven up as gases and vapors most however react with oxygen of the crucible to form a slag or dross at the top of the mountain we pour the purified metal right out from underneath the dross to form an ingot like this having uranium is heavy that clean metal then can be used to fabricate new fuel pens we use a technique called injection casting at this station is the injection casting furnace after casting each of the Pens is inspected for weight length diameter and Vario you know I'm amazed at the complexity and also the variety their different instruments how that looks to me exactly like a parasol that is periscope we use that to obtain close-up views of items inside the cell when necessary after inspection each pin is inserted into a thin stainless steel jacket in this manner a small amount of sodium is added to provide a thermal plan between the fuel pin and the steel jacket then using the sodium settling furnace we melt the sodium and uniformly distributed throughout the fuel element finally an enclosure is added and welded that completes the fuel element new fuel elements such as this identical to be used fuel elements originally brought into the building except of course - deficient products these new fuel elements are transferred from the argon cell back to the air cell here an enormous Lea complicated remotely manipulated machine places 91 fuel elements on the grid structure of a new fuel assembly later the blanket sections are added and the stainless steel outer can slipped over the assembly this completed fuel assembly finally is removed from the air cell placed in the coffin taken back to the reactor plant and inserted in the reactor thus completing the fuel cycle thank you very much dr. Monson there's really been a very fascinating tour in this past half-hour we've had just a very brief look at the future of atomic power and this of course is just the beginning as a special Atomic Energy Commission report that was prepared for the president back in 1962 said breeder reactors will enable us to use all of our available nuclear resources in the making of fuel the future value of a given amount of uranium can be multiplied by much more than 100 times and this fact makes our reserves almost limitless because we have vast deposits of low-grade uranium ore after all every piece of granite contains some uranium with the development of the breeder reactor we can now begin to see that nuclear energy is economically reasonable and that it can be produced on a massive scale as a matter of fact nuclear power has already become competitive with conventional plants in some parts of the country and by the year 2000 more than half the electric power of the country will come from atomic sources we have indeed just begun said Thomas Alva Edison back in 1921 and that was some 20 years before the advent of the Atomic Age not only will atomic power be released someday we will harness the rise and fall of the tides and imprison the Rays of the Sun [Music] Challenge has been produced through a grant from the United States atomic energy Commission's Argonne National Laboratory argon is operated by the University of Chicago this has been a Ross McElroy production for national Educational Television

Channel: Nuclear Engineering at Argonne

Views: 40,255

Keywords: nuclear, reactor, EBR-II

Id: cIeE9NMP8Oc

Length: 29min 27sec (1767 seconds)

Published: Mon May 14 2018