Tatical employment of A-Bomb in Japan

[Andy H]

Just come across a article that mentions, that if the bombings of Hiroshima & Nagasaki in 1945 hadn't resulted in Japan's surrender, then the 3 US Corp's commanders in the projected "Op Olympic" would have been given between 2-3 A-Bombs for tatical use near or just beyond the intial beachead.

A couple of questions please:

What was the production rate of A-Bombs like at this time, enough to furnish what is stated above, and if not when would they be available in relation to a proposed invasion of Japan?

If used as envisaged just beyond the Beachead, did the US Army/Marines have the means to advance through such an area after the explosion?

Logistically could the US have coped with the civilian casualties as they passed through these area's and what real advantage would they gain from there use?

Regards

Andy H

[Mark V]

Just come across a article that mentions, that if the bombings of Hiroshima & Nagasaki in 1945 hadn't resulted in Japan's surrender, then the 3 US Corp's commanders in the projected "Op Olympic" would have been given between 2-3 A-Bombs for tatical use near or just beyond the intial beachead.

Andy H

Hi,

That kind of use might have been unpractical IMHO. Few reasons:

- Inaccuracy of delivery: - only B-29 could carry nuke and it was mandatory to drop it from very high altitude (for sake of flight-crew safety)
- The characteristics of Japanese defence: - well dispersed, camouflaged troops, and their well proven capacity to keep on fighting in small independent units, even if chain of command and logistics had been broken
- The characteristics of average Japanese trooper: - if there is one nation whose soldiers could cope psychologically the effects of seeing a square miles of total incarnation with his own eyes and still continue fighting effectively - it was Japanese soldier for sure
- Lack of protection of own troops: - US troops were not equipped against radiological hazards - like NBC proof mask filters (normal WW2 -era gas mask filters were not designed against radioactive particles). Common knowledge measures against chemical weapons, like covering all exposed skin and washing material (and men) suspected being contaminated with water are on the right way also here, but not enough when respiratory tract of foot soldiers is fully exposed. - Though with high enough detonation the radiological effects could be somewhat limited and those men in first invasion waves could have won the battle - the ill effects would had come later - but for sure the cemetaries behind veteran hospitals would had to be enlarged...

Road and railroad crosspoints well in inland would have been more suitable targets, but hey - by that time they would had already been bombed to rumbles with conventional weapons.

About the bomb availability: Enough of them. If war would had continued, the production rate in late autumn 1945 would have been somewhere between 6-8 nukes per month. In early 1946 10-12 per month. All stories about lack of bomb material in summer 1945 are just extremely short-sighted views. Oak Ridge K-25 Plant was coming fully on-line in latter part of 1945, Hanford was producing Plutonium like Ford their T-models in 20s . And US also had in reserve the magnetic separation capacity which they shut down immediately when war ended...


Regards, Mark V

[Mark V]

Small addition:

A high altitude detonation (to avoid radioactive fallout) of nuclear bomb would make it largely ineffective against Japanese troops also.

Most Japanese would, with all propability had been in **:

- foxholes
- caves
- covered pillboxes and bunkers

Quite well protected against effects of blast wave and thermal radiation. And small nausea because of acute radiation sickness doesn't stop determinated Jap machinegunner operating effectively for several days... (Men inside covered MG pillbox just few hundred metres from point of ground zero in Hiroshima/Nagasaki like detonation altitude have quite reasonable chances to live for another day *** and fight)

I think the only way to gain effective (and very local) elimination of defence would be using ground (or very low altitude) detonation - which would had exposed the US troops crossing that area later to very high radiation levels. And if luck run out the wind turns suddenly and push the fallout cloud directly to invasion shore and ships just out of that shore...

Kinda risky scenario.

Mark V


** tactical nukes are far more effective against attacker in move than against defender

*** shocked, bruised, burned and doomed because direct Gamma radiation, but capable for at least limited operating capacity for several days

[Andy H]

Thanks Mark V for your responses.

I was somewhat sceptical of there tatical use and everything you've posted supports this. It would be more of a hinderance to the US both militarly and politically if they were used. Thanks also for the info on A Bomb production I to thought that they were in somewhat short supply, but from your posts it seems not.

Andy H

[Mark V]

It would be more of a hinderance to the US both militarly and politically if they were used.

My opinion also.

Little sidenote about nuclear weapons production:

US fissionable material production started truly at the last months of 1944 and and by late summer 1945 they had produced enough for 3-4 weapons. Not too bad for such ground breaking technology ?? But it was just the start of development...

- HEU production for "Little Boy" was coming mainly from extremely expensive (electricity consumption was huge) Y-12 magnetic separation plant in Oak Ridge. New, and vast, just finished (in 1945) K-25 gaseous diffusion separation plant *** in same location played only a small part in production of fissionable material during WW2, but was the first mass production site of HEU in Cold War years after truly successfull barrier material had been developed in latter part of 1945...

- Hanford reactors suffered some structural defects after initial year or two of operation, but all 3 were still all the time capable for their maximum output of thermal 250 MW (about 250 grams of Plutonium per reactor per day, about 6kg of Pu is sufficient for simple 1st gen. weapon) if pushed because of wartime urgency.

Don't forget that by late 1945 all US HEU production would had been for composite or pure HEU implosion weapon designs - "Little Boy" was just one of a kind insurance policy, which was unnecessary after Trinity had proofed the design of much more efficient (in consumption of fissionable materials) implosion nuclear weapon.

Regards, Mark V



*** http://www.fas.org/irp/imint/doe_ornl_k25_3.jpg

[gabriel pagliarani]

Little sidenote about nuclear weapons production:

US fissionable material production started truly at the last months of 1944 and and by late summer 1945 they had produced enough for 3-4 weapons. Not too bad for such ground breaking technology ?? But it was just the start of development...

- HEU production for "Little Boy" was coming mainly from extremely expensive (electricity consumption was huge) Y-12 magnetic separation plant in Oak Ridge. New, and vast, just finished K-25 gaseous diffusion separation plant *** in same location played only a small part in production of fissionable material during WW2, but was the first mass production site of HEU in Cold War years after truly successfull barrier material had been developed in latter part of 1945...

- Hanford reactors suffered some structural defects after initial year or two of operation, but all 3 were still all the time capable for their maximum output of thermal 250 MW (about 250 grams of Plutonium per reactor per day, about 6kg of Pu is sufficient for simple 1st gen. weapon) if pushed because of wartime urgency.

Don't forget that by late 1945 all US HEU production would had been for composite or pure HEU implosion weapon designs - "Little Boy" was just one of a kind insurance policy, which was unnecessary after Trinity had proofed the design of much more efficient (in consumption of fissionable materials) implosion nuclear weapon.

Regards, Mark V



*** http://www.fas.org/irp/imint/doe_ornl_k25_3.jpg

The limit was not in fixionables which production was exponentially increased as Mark V draft, but in logisticals. Fast Neutron Feeding Reactors were busy in producing Plutonium. Only in 1947 they were intensively used in producing artificial isothopes as Polonium 208 having decay mid-life of 100 years suitable for Po/Be igniters. Till 1947 only natural Polonium 210 was suitable for such use. Polonium 210 is an extremely rare contaminant of Radium, which is an extremely rare contaminant of U 233, which is a rare contaminant of U235, wich is a rare contaminant of Uranium which is rarely disperded in Pechblenda ores....note that difficult and surely not exponential-law increasing production.Mid-life decay of Po210 is 138 days only, and without Po/Be igniter a Plutonium 239+240 implosion bomb "fizzs" without exploding. Consequently between 1945 and 1947 the exponential mass production of A-bombs was simply not possible in USA. About the tactical use of A-bomb, the very 1st test facing GI troops was done after WW2. Using such a weapon without any former evaluation and testing is simply a suicide. This question was made by Mac Arthur during Korean War: he evaluated the possibility to drop A-bombs on incoming Chinese troops over 38th Parallel. Obviously the reply was that US troops were not ready in this evenience. This fact occurred in 1950-1951.

Post Scriptum.
Gas diffusion plants are used in dividing U238 and U235 only. Uranium Hexafluoride (F6U) is divided by mean the heavy mass of U238 by centrifugation. U235 is fixile, but U238 must be exposed in an Fast Neutron Breeding Reactor to become fixile Plutonium 239 and Plutonium 240. You cannot produce more Plutonium of the main U238 not-fixile isothope you had before. Y12 magnetic separation plant had the task to divide U233 from U235, an exhaustive activity necessary to reach the wide critical masses of breeding reactors: large part of initial fixile production was drained by the same reactors. Only Plutonium was totally useful for bombs till 1950 because breeding reactors were finally ready for large scale.

[Mark V]

The limit was not in fixionables which production was exponentially increased as Mark V draft, but in logisticals. Fast Neutron Feeding Reactors were busy in producing Plutonium. Only in 1947 they were intensively used in producing artificial isothopes as Polonium 208 having decay mid-life of 100 years suitable for Po/Be igniters. Till 1947 only natural Polonium 210 was suitable for such use. Polonium 210 is an extremely rare contaminant of Radium, which is an extremely rare contaminant of U 233, which is a rare contaminant of U235, wich is a rare contaminant of Uranium which is rarely disperded in Pechblenda ores....note that difficult and surely not exponential-law increasing production.

Po-210 was rare indeed. But not a problem for US which could use nearly unlimited resources for everything (like hundreds of tons of silver for coiling of electrical equipment when copper was in short supply :roll: ).

Possible production increase in 1945-46 was not even nearly exponential. Just steady development (exponential growth came only after Joe-1).

Regards, Mark V

PS. Not even starting discussion about ways to elimaminate Po-210 totally out of production cycle - like high-effeciency HEU *** double gun designs, and Tritium initiators. Also "urchin" design was quite conventional and could easily be streched to more weapons per given amount of Po-210 with little effort.

BTW. All production reactors in this planet in mid 40s were "slow" neutron reactors, not fast breeders... (first fast reactor was a research reactor in 1946-47 IIRC)...

*** Increase in fissionable material production came at that time almost entirely from HEU production which gives us plenty of alternative weapon designs available.

[Mark V]

Hi,

Gas diffusion plants are used in dividing U238 and U235 only. Uranium Hexafluoride (F6U) is divided by mean the heavy mass of U238 by centrifugation.

Gaseous diffusion separation and centrifugal separation have nothing to do with each other. Did you know that ?? They are totally different production methods of enriched Uranium (i don't use term HEU here because most products of enrichment plants are not HEU - but commercial grade reactor fuel). Both methods are used today commonly. During WW2-era only gaseous diffusion was used.

U235 is fixile,

Fissile. And very good material for making of bombs.

but U238 must be exposed in an Fast Neutron Breeding Reactor to become fixile Plutonium 239 and Plutonium 240. You cannot produce more Plutonium of the main U238 not-fixile isothope you had before.

How this discussion turned to advantages of fast breeders ?? Yes, they can produce more fissile material than they consume - but they can also explode much more effectively than other reactor types , which is why they are not so popular anywhere. And they have nothing to do with Plutonium production for military purposes during WW2 (or later for that matter).

Only Plutonium was totally useful for bombs till 1950 because breeding reactors were finally ready for large scale.

Tell that to any people who lived in Hiroshima... and believe me - Pu production (emphasize in word production, not futile research), reactors for military purposes are slow reactors - fast reactors have proven to be just expensive dreams, not practical solutions - i myself would not live under 100 miles of reactor of that type voluntarily, i wan't to live to my golden years...


Regards, Mark V

[gabriel pagliarani]

About gaseous diffusion you are right, I have read your post too fast. Where do you think Plutonium of Nagasaki's bomb came out? There is not natural Plutonium! About breeding reactors no, you are wrong. Slow motion neutrons break (fission is a latin word having the same meaning) heavy target nuclei. This is the principle of chain reaction. High speed neutron are captured by heavy nuclei: following other complex rules sometimes the new added neutron purchase a positive charge and those nuclei are trasmutated in Heavier Elements having other chemical behaviours. This is the trasmutation. Reasuming:
LOW SPEED NEUTRONS=FIXION OF FIXILES (or fissiles if you like latin words)
HIGH SPEED NEUTRONS=TRASMUTATION (or enrichment as you defined)
Breeding reactors for military use never produced electrical power: this kind of power plants were called Super Phoenix, they are for civilian use and at today they are still in use in South Korea and Japan. The coolant is not water but molten metals like Sodium or Bysmuth/Lead ipo-thectical alloy.Watch the following site:
http://isnwww.in2p3.fr/reacteurs-hybrid ... ode15.html
"Converters and breeders allow full use not only of the fissile 235U isotope, but also of the fertile 238U and 232Th isotopes. Thus, in principle, a 1 GWe reactor requires only 1 ton of natural Uranium or an equivalent amount of Thorium. This means that, at the current market cost, assuming a production capacity of 2500 GWe, corresponding to a nuclear share of 30% in the total energy production, the reserves would amount to 6000 years for natural uranium and about 4 times more for thorium. In fact the very effective use of the uranium and thorium would allow the use of very poor ores, including the sea water uranium, which means that the resources would be practically infinite. The mill tailings would also be considerably reduced by more than a factor 100.While the Plutonium present in spent fuels has to be considered as a waste, it is the fissile material for breeders and converters. Only long lived fission products(LLFP) and minor actinides(MA)2.11 can, thus, be considered as nuclear wastes. In the absence of specific transmutation of these wastes, their radiotoxicity, after a cool down period of 300 years2.12, would be, at least, one order of magnitude smaller than that of the PWR spent fuels, for an equivalent energy production. Since fuel reprocessing is a prerequisite for any breeding or converting cycle it is quite natural to consider the possibility of transmutation the LLFP and MA. We shall discuss such a possibility in some detail below. It is shown that incineration of MA and transmutation of some of the most significant LLFP appear to be feasible. Nuclear wastes would, then, be reduced to the reprocessing losses. Modern reprocessing is claimed to have 99.9% efficiency in the recovery of Plutonium and 99% in the recovery of MA[110]. It would, then, be possible to reduce the total radiotoxicity of the wastes by several orders of magnitude after a few hundred years of cooling time. With such a reduction, long term storage might not be necessary."
Modern ones for civilian purpose produce fuel and electricity, ancient ones produced only transmutated elements suitable on bombs.
http://www.bonestamp.com/sgt/breeding_reactors.htm
From the above site:

2.0 IRRADIATION PROCESSING AT THE HANFORD SITE

2.1 HANFORD'S SINGLE PASS REACTORS

Nine plutonium production reactors, now closed and silent, cluster along a 14-mile (22.53 kilometers) stretch of the Hanford shoreline of the Columbia River. Eight of these reactors, all except the N Reactor, are known as "single-pass" reactors due to the once-through nature of their light water cooling systems. Known as "piles" in the 1940s, these machines drew cooling water from the river, and pumped it through a series of filtration, chemical treatment, and storage buildings and tanks. The water then was passed directly through long, horizontal tubes in the reactors, where the solid, Al-Si-jacketed uranium fuel rods underwent active neutron bombardment. From there, the water was pumped out the back of the piles, left for a brief time (30 minutes to 6 hours) in retention basins to allow for short-term radioactive decay, and then returned to the Columbia River.[xxii]

2.1.1 Historic Significance of B-Reactor

Hanford's original reactor, B, was the first such full-scale nuclear facility to operate in world history. Built by the Army Corps of Engineers and the DuPont Corporation in just 11 months between October 1943 and September 1944, it now is listed on the National Register of Historic Places. B Reactor also has received special awards from the American Society of Mechanical Engineers and the American Society of Civil Engineers.

2.1.2 Single-Pass Reactor Buildings

The next seven reactors, D, F, H, DR, C, KE, and KW (in order of construction) were similar in most features. Built between 1943 and 1955, and shut down between 1964 and 1971, they had an average life span of just 21 years. The construction and general specifications of B, D and F Piles (the original three reactors built in World War II) were similar to those of most of Hanford's other single-pass reactors, although C, KE and KW were slightly larger and contained some special features. All of the piles rested on thick concrete foundations topped with cast iron blocks. The reactor buildings themselves were reinforced concrete structures shaped like tiered wedding cakes with no containment domes. They sat near the centers of five separate reactor areas of approximately 700 acres (283.28 ha) each.
The core of each reactor was a series of graphite blocks that fitted together. In the oldest six reactors, the cores each measured 28 feet (8.53 meters) from front to rear, 36 feet (10.97 meters) from side to side, and 36 feet (10.97 meters) from top to bottom. In the K-Reactors, the cores each were 33 feet (10.06 meters) from front to rear, 40 feet from side to side, and 40 feet (12.19 meters) from top to bottom. The graphite served as the "moderator" to slow and absorb extraneous neutrons from the basic nuclear chain reaction. Each stack was pierced front to rear by aluminum process channels that held the fuel elements. The first six Hanford reactors each contained 2,004 process channels, and the KE and KW Reactors each contained 3,220. The "lattice," or pattern of process channel configuration was a simple rectangle, with only the corners of the core bearing no penetrations. Each reactor's graphite core was surrounded by thick thermal and biological shields. The core and shields formed the reactor "block," and each block was enclosed in a welded steel box that functioned to confine a gas atmosphere. The atmosphere of the earliest reactors was composed of helium, an inert gas selected for its high heat removal capacity.[xxiii]
At the front and rear of each process channel, a carbon steel exit and entry sleeve known as a "gunbarrel" penetrated the pile shields. The ends of each process tube flared into flanges to facilitate a close fit and interface against the gunbarrels. Asbestos gaskets lay between the flanges and the stainless steel nozzles that projected from the front and rear of each process tube. The nozzles connected to coiled lengths of aluminum tubing known as "pigtails" (originally one-half inch (1.27 centimeters) in diameter but later larger), which in turn connected to stainless steel crossheaders. Devices known as "Parker fittings"a connected the pigtails to the crossheaders. The crossheaders [originally 39 sections of four-inch- (10.16-centimeter-) diameter pipes] served to break down the huge water supply entering the reactor building's valve pit via two 36-inch- (91.44-centimeters-) diameter headers, then two 36-inch (91.44 centimeters) risers.[xxiv]
Test holes extended from the right side of each Hanford pile for the irradiation of experiments and special samples. Horizontal channels for control rods (HCRs) entered from the left side of each reactor, and vertical channels for safety rods (VSRs) entered from the top. The control and safety systems functioned simply to absorb neutrons, thus slowing and eventually stopping the controlled chain reaction of neutron exchange between the uranium fuel elements.
The early Hanford reactors also were equipped with various safety and control instruments that measured temperature, pressure, moisture, neutron fluxb and (radio)activity levels in the byproducts of the fission reaction. Because no one instrument had enough range to measure neutron flux all the way from shutdown (background) levels to the approximately 1,000,000,000,000 (1 trillion) times background levels experienced during operations, each reactor was fitted with sub-critical, mid-range and full power flux instrumentation.[xxv]

2.1.3 Operation of the Single-Pass Reactors
During actual operations, raw water was pumped from the Columbia River by pumphouses (known as 181 Buildings) located at and partially in the river. From there, water for the earliest reactors was pumped to the 182 Buildings, which routed much of the water to the 183 Buildings for chemical treatment, settling, flocculation and filtration. A small portion of the water proceeded directly from the 182 Buildings through large concrete pipes to the Hanford's 200 Areas [located 6 to 8 miles (9.66 to 12.87 kilometers) away] for treatment and use there in chemical separations and other operations. From the 183 Buildings, Hanford's reactor process water was pumped to the 190 Buildings and stored in huge "clearwells" ready for pile use. In the 190 buildings, sodium dichromate was added to the water to prevent corrosion of pile process tubes. The 190 Buildings then supplied the reactors themselves as needed. Some of the earliest HEW reactor influent systems also contained 185 Buildings for dearation, and 186 Buildings for refrigeration of coolant water. However, these functions were found to be unnecessary and the 185 and 186 Buildings were diverted to other uses.
At HEW's earliest reactors, each process tube usually was charged with 32 U fuel elements, along with a few dummy slugs in various configurations (either solid or perforated and hollow) at each end of the process channel. Many fuel configurations could be used to achieve various desired flux patterns across the reactor lattice.

2.1.4 Change and Experimentation in Production Process

The history of Hanford's single-pass reactor operations is one of constant change and experimentation. Many questions puzzled and intrigued early Hanford scientists. For example, they worried about the possibility of "slug failures," or the accidental penetration by cooling water of the aluminum jackets surrounding the fuel elements. They knew that such penetration would cause the uranium to swell, thus blocking the coolant flow within the process tube. This condition would necessitate tube removal and replacement, and could melt the fuel elements in that tube. Also, fuel ruptures would allow the escape of radioactive fission products in larger than average amounts.[xxvi]
Another topic that intrigued the early operators of Hanford's reactors was that of temperature and neutron flux distribution. At first, "poisons" (neutron absorbing materials) were distributed in a uniform pattern throughout the reactor core during operation. This method of control produced a flux pattern that resembled a cosine (or bell) curve, front to rear within the pile. Such a curve meant that while uranium elements in the center of the reactor achieved maximum or optimum irradiation, many of the fuel elements located in the rest of the reactor achieved sub-optimal irradiation, due to lower neutron flux. This situation not only was inefficient in terms of utilization of the uranium supply, it also contributed to temperature gradients that caused expansion in the graphite in the central portions of the pile.
Shortly after World War II, Hanford scientists tested several new poison patterns, with the goal of "flattening" the pronounced cosine curve, thus evening out the distribution of neutron activity and enlarging the area of maximum flux and temperature within the reactor. Quickly, they learned that many alterations in poison distribution (control rod positions) would achieve higher and lower temperatures and exposures in various reactor zones. They dubbed all of these manipulations "dimpling" the reactor.[xxvii]

And so on. Mark V, you are lucky: I worked for Du Pont de Nemours of Italy from 1986 to 1991: I REALLY know a lot about that company.

[Wulpe]

That kind of use might have been unpractical IMHO. Few reasons:

[...]
- Lack of protection of own troops: - US troops were not equipped against radiological hazards - like NBC proof mask filters (normal WW2 -era gas mask filters were not designed against radioactive particles). Common knowledge measures against chemical weapons, like covering all exposed skin and washing material (and men) suspected being contaminated with water are on the right way also here, but not enough when respiratory tract of foot soldiers is fully exposed. - Though with high enough detonation the radiological effects could be somewhat limited and those men in first invasion waves could have won the battle - the ill effects would had come later - but for sure the cemetaries behind veteran hospitals would had to be enlarged...

That would have been no problem, because the whole radiation hazard was quite unknown it this time. My physics teacher was a Mormon, he told me he (as a kid) and his family were watching nuclear tests in the Utah desert in the 50´s while having a picnic.

I couldn´t find such a picture, but here is one of Las Vegas:



The caption reads: This is the famous 1951 photo of a distant mushroom cloud as seen from downtown behind the "Vegas Vic" cowboy sign in Las Vegas, Nevada. Many GIs, Reporters and Spectators viewed the atomic explosions at the Nevada Test Site's observation area, a place known as News Nob, the intensity of the white flash and rapidly changing light baffled persons who viewed the blasts, they were in awe and had to look away to avoid eye damage. The explosion GIs, Reporters and Spectators witnessed was potent enough to break windows in Las Vegas, 75 miles distant.

[gabriel pagliarani]

NATO defensive doctrine ("display determination") during early '60, just before the actual doctrine called " flexible reply", forecasted the use of tactical nukes to be launched directly on incoming armoured piercing motorized units of Warsaw Pact. The front-line and invaded countries to be tactically bombed would be BDR,DDR,CS,H, I. There was no other way to stop a number of red tanks evaluated from 3:1 to 6:1 respect with NATOs' tanks. Officially there was no NATO plan to invade Red Block after tactical nuking and the reason was that only Special Forces and few skilled men were able to invade nuked areas just after waiting for at least and not less than a couple of weeks, when radiation hazard was halved. Neutrality held by Osterreich could never avoid an heavy bombing because surely invaded just before Germany and Italy: we are still living by a gift of Divine Providence.

[Mark V]

Gabriel,

Nice copy and paste to confuse anyone reading this thread - but let's make some facts clear anyway.

It seems that you don't understand that it doesn't need fast breeder reactor to breed Plutonium...

Ofcourse all military Pu-production reactors were build to "breed" (produce) Pu-239, but they were still slow, thermal reactors. Meaning that they all used some matter (graphite, heavy water), to slow down the neutrons, and because of that they all consumed more U-235 than they produced Pu-239 ***, which really doesn't matter anything militarily-wise if natural Uranium could be used - it is still much more easier way to produce weapons-grade fissile material than physical separation of U-235 from natural Uranium.

Fast reactor is totally different (and dangerous) design, which characteristics i don't care to dig deeper here. Anyone interested can find easily information about it's working principles. But to make it sure: it has nothing to do with Manhattan Project -era Pu production, or mass-production of Pu during Cold War -era. Production was done in slow, thermal reactors (and BTW some also in plants that produced electricity - contrary what you stated).

Regards, Mark V


*** Theoretical ineffeciency of this design has resulted to all those projects for development of viable fast reactor that doesn't use moderator matter at all, and has negative fuel consumption - produce more fuel than it consumes.