Atomic bomb

Good post Clint, I was going to steal your response from this other thread, but decidied you would be along in due time.
http://www.ww2f.com/war-pacific/13753-there-third-atomic-bomb-target.html

Richard Frank mentions in Downfall that an additional 17 bombs could have been completed by year end 1945.I'de Have to track down the page number but that fits in pretty well with the numbers you posted.

 

The US did not have enough enriched Uranium to make 17 bombs by the end of 1945

 

All I have to say to this and any other critic of the bombs is this: You weren't there and you would not have had to go in.

MacArthur was a dope, This is the same man who advised dropping nukes on China. He is also was hungry for glory. What could be more glorious than invading and conquering Japan--something that hadn't happened in 1500 years? I'll take his words witha huge grain of salt.

Eisenhower from 43' on was focused on the ETO, so what did he really know about the Japanese other than what he read from reports?

The other noted dissident was Leahy--a career distinguished by nothing of note.


The anti-bomb people should read the memoirs and reports of Vandegrift, Puller, Holland Smith, Nimitz, Halsey, and Spruance about the Japanese. What did these men--those who came closet in contact with the enemy--have to say?

If Douglas MacArthur is your lone direct source, than your argument is in trouble for the aforementioned reasons.

 

I'm thinking Richard Rhodes says in his books they did have fissionable material.

 

Oh but we (MED) did have the ore for the processing, not only did we have all the millions of pounds of ore from Canadian Great Bear Lake, we also had all the ore from the Belgian Congo (the best in the world), and the tons of U-238 uranium oxide the Nazi scientists had begun processing and refining. With the facilities for the production of the enriched uranium and plutonium just coming into their own, those bomb cores could have been made.

There was 1100 TONS of Czech ore from Stutgartt which was put in the "pipeline" of the MED as soon as it got back to the states. And another 1000 kilos of uranium oxide which was on the U-234 (#?), which also went into our system when it was captured.

The Colorado Plateu had been discovered and mining just started there as well. The possibility of those numbers of bombs is NOT out of the realm of possibility. Groves wasn't an optomist when it came to his production capabilities, he generally "understated" the situation as a hedge against any surprises.

 

Brndirt, yes, there is no argument from me about the amount of raw uranium available for refinement.

But the number of US atomic weapons available for use as of June 1946 stood at six.

Atomic Bomb Chronology: 1945-1946

 

Too true, but that was the post-war production when the enrichment facilities were put on hold. Not the number of bomb cores which "could" have been constructed if the war had continued past August of '45.

Two different situations completely. The production of the plutonium and U-235 had been removed from the MED (Army) and turned over to the AEC (civilian) for control. At that moment in time nobody knew exactly what was going to happen with the need for more bombs since we (allies) were the only ones with the damn thing.

 

One more thing. Here is the kind of information I base my suppositions of bomb production upon:

The date that a third weapon could have been used against Japan was no later than August 20. The core was prepared by August 13, and Fat Man assemblies were already on Tinian Island. It would have required less than a week to ship the core and prepare a bomb for combat.

By mid 1945 the production of atomic weapons was a problem for industrial engineering rather than scientific research, although scientific work continued - primarily toward improving the bomb designs.

The three reactors (B and D which went started up for production in December 1944, and F which started up February 1945) at Hanford had a combined design thermal output of 750 megawatts and were theoretically capable of producing 19.4 kg of plutonium a month (6.5 kg/reactor), enough for over 3 Fat Man bombs. Monthly or annual production figures are unavailable for 1945 and 1946, but by the end of FY 1947 (30 June 1947) 493 kg of plutonium had been produced. Neglecting the startup month of each reactor, this indicates an average plutonium production 5.6 kg/reactor even though they were operated at reduced power or even shut down intermittently beginning in 1946.

Enriched uranium production is more difficult to summarize since there were three different enrichment processes in use that had interconnected production. The Y-12 plant calutrons also had reached maximum output early in 1945, but the amount of weapon-grade uranium this translates into varies depending on the enrichment of the feedstock. Initially this was natural uranium giving a production of weapon-grade uranium of some 6 kg/month. But soon the S-50 thermal diffusion plant began feeding 0.89% enriched uranium, followed by 1.1% enriched feed from the K-25 gaseous diffusion plant. The established production process was then: thermal diffusion (to 0.89%) -> gaseous diffusion (to 1.1%) -> alpha calutron (to 20%) -> beta calutron (up to 89%). Of these three plants, the K-25 plant had by far the greatest separation capacity and as it progressively came on line throughout 1945 the importance of the other plants decreased. When enough stages had been added to K-25 to allow 20% enrichment, the alpha calutrons were slated to be shut down even if the war continued.

After Japan's surrender in August 1945, S-50 was shut down; the alpha calutrons followed in September. But K-25 was complete on August 15, and these shutdowns would have occurred in any case. At this point gaseous diffusion was incapable of producing weapon grade uranium, a planned "top plant" had been cancelled in favor of more beta calutrons. An expansion of K-25, called K-27, to produce a larger flow of 20% enriched feed was under construction and due to go in full operation by 1 February 1946. In October production had increased to 32 kg of U-235 per month.

In November and December additional beta tracks went on line, and the percentage of downtime for all beta tracks fell, boosting production further. Between October 1945 and June 1946, these improvements led to a 117% increase in output at Oak Ridge, to about 69 kg of U-235 per month. (bold mine)

It is very unlikely any more Little Boy-type bombs would have been used even if the war continued. Little Boy was very inefficient, and it required a large critical mass. If the U-235 were used in a Fat Man type bomb, the efficiency would have been increased by more than an order of magnitude. The smaller critical mass (15 kg) meant more bombs could be built. Oppenheimer suggested to Gen. Groves on July 19, 1945 (immediately after the Trinity test) that the U-235 from Little Boy be reworked into uranium/plutonium composite cores for making more implosion bombs (4 implosion bombs could be made from Little Boy's pit). Groves rejected the idea since it would delay combat use.

The improved composite core weapon was in full development at Los Alamos when the war ended. It combined two innovations: a composite pit containing both U-235 and Pu-239, and core levitation which allowed the imploding tamper to accelerate across an air gap before striking the pit, creating shock waves that propagated inward and outward simultaneously for more rapid and even compression.

Production estimates given to Sec. Stimson in July 1945 projected a second plutonium bomb would be ready by Aug. 24, that 3 bombs should be available in September, and more each month - reaching 7 or more in December. Improvements in bomb design being prepared at the end of the war would have permitted one bomb to be produced for every 5 kg of plutonium or 12 kg of uranium in output. These improvements were apparently taken into account in this estimate. Assuming these bomb improvements were used, the October capacity would have permitted up to 6 bombs a month. Note that with the peak monthly plutonium and HEU production figures (19.4 kg and 69 kg respectively), production of close to 10 bombs a month was possible.

When the war ended on August 15 1945 there was an abrupt change in priorities, so a wartime development and production schedule did not continue. Development of the levitated pit/composite core bomb ground to a halt immediately. It did not enter the US arsenal until the late forties. Plans to increase initiator production to ten times the July 1945 level were abandoned. (bold mine)

Fissile material production continued unabated after the S-50 and alpha calutron shutdowns though the fall, but plutonium shipments from Hanford were halted, and plutonium nitrate concentrates were stockpiled there.

In early 1946, K-25 and K-27 were reconfigured to produce weapon grade uranium directly, but the extremely costly Y-12 beta tracks continued to operate until the end of 1946. By that time Y-12 had separated about 1000 kg of weapon grade uranium. From this point on gaseous diffusion enriched uranium was the mainstay of weapon grade fissile material production in the US, dwarfing plutonium production, until highly enriched uranium production for weapons use was halted in 1964. (bold mine)

The Hanford reactors accumulated unexpected neutron irradiation damage (the Wigner effect) and in 1946 they were shut down or operated at reduced power. If war had continued they both would have been pushed to continue full production regardless of cost or risk.

The effects of these priority changes can be seen in the post war stockpile. Although Los Alamos had 60 Fat Man units - that is the non-nuclear components to assemble complete Fat Man bombs - on hand in October 1945, the US arsenal after had only 9 actual Fat Man type bombs in July 1946, with initiators for only 7 of them. In July 1947 the arsenal had increased to 13 bombs. There was probably sufficient fissile material on hand for over 100 bombs though. (bold mine)


See:

Availability of Additional Bombs

The end of the war had not only slowed down the production rates of plutonium and U-235, the construction of the initiators which set them off had come to nearly a complete halt. If the war hadn't ended however, the initiator production would have also continued at the war-time rate. Or I should say that I see no reason we wouldn't have done so.

 

I cannot remember the sources, but the atomic bomb production was still a top priority program even after the surrender of Japan.

Somewhere in these archives, it has the information.

The Nuclear Weapon Archive - A Guide to Nuclear Weapons

 

Perhaps that's why Plutonium was used for some.

Well according to:
Hanford and HistoryB Reactor 60th Anniversary Banquet AddressOctober 9
Hanaford shipped:

 

They needed enriched Uranium (238) to make Plutonium.

 

No they didn't. See:
The World's First Plutonium Production Reactor

*** bolding mine ***

 

I was going to mention that "lwd", since 238 is uranium oxide ore, the natural state. While that is non-enriched, it is possible that it was "refined" to a higher concentration however, it just isn't "enriched" to the isotope 235 state.

And since you included the "graphite" part, I should point out that the use of "heavy water" as a moderator for our plutonium facilities wasn't online until post war. We got out deuterium from British Columbia the only other commercial producer in the world when the Norsk Hydro plant fell into Nazi hands. But didn't use that as a moderator until post war. We stuck with the Fermi graphite style.

 

The Atomic Bomb: 6 August 1945. Propaganda Leaflet Dropped on Japanese Cities








Source: The National Security Archive



The Only Order to Actually Use Nuclear Weapons, 25 July 1945





The Atomic Bomb, 31 July 1945: Truman's Statement on the Bombing of Hiroshima Original Top Secret Documents. Check link theres one more.

Google Image Result for http://longstreet.typepad.com/thesciencebookstore/images/2008/07/29/atomic_bomb_target_selection.jpg



Atomic Bomb--the Cautionary Letters of "Einstein and Szilard," 1939-1945

See Bottom Link for all the Letters

http://www.google.ca/imgres?imgurl=...l=en&sa=G&rlz=1T4ADRA_enCA331CA336&tbs=isch:1

 

While it is true that leaflets were dropped, they weren't dropped before the atomics were deployed. Not in either case, we didn't want the Japanese to know where they were going to be dropped for fear of them moving POWs into the areas.

On August 7th, the day after the Hiroshima bombing, it was undertaken to print and distribute millions of leaflets to other major Japanese cities warning of "future atomic attacks".

Clearly not before the "atomics" were deployed. The leaflet dropping, and warnings to Japan by Radio Saipan began on August 8th, between the two "atomics". Nagasaki itself did not receive any "atomic" warning leaflets until August 10th, the day after its own bombing.

 

On the otherhand leaflets were dropped on both cities (as well as others) indicating that they were subject to bombing prior to the bombs being dropped. See:
[Photo] LeMay bombing leaflet; over 5 million of them were delivered to Hiroshima, Nagasaki, and 33 other Japanese cities by 1 Aug 1945, encouring Japanese citizens to flee from cities for safety | World War II Database

 

This question always gets me-Should we have dropped the bombs on Japan? They were going to surrender anyway, right? I think that in order to answer this question one needs to analyze what was going on in Japan. There is an awful lot of information that has somewhat recently been released, translated and analyzed. What is known is that in the summer of 45 the Supreme War Council, AKA the Big Six, was tasked by the Emperor to find a way to end the war. This council was split into two factions, the peace faction, which included the Prime Minister Suzuki, foreign minister Togo, and Navy Minister Yonai. The faction for continuing the war included Army Minister Anami, Army Chief of Staff Yoshijiro, and Navy Chief of staff Toyoda.

While all of these people realized that the war was lost the war faction insisted on conditions for capitulation that included not only keeping the Emperor, but also holding on to Manchuko (Manchuria) and no international war crimes trials. Conditions that they all knew would not be accepted by the allies.

The first bomb devastated Hirohito, he urged the council to come up with a solution immediatly, but they remained deadlocked. On August ninth with the double shock of the Soviet entry into the war and the Nagasaki bomb the council met all day, but still was deadlocked. They met that night in the bomb shelter of the Imperial Palace, a meeting in which the Emporer in an unprecidented move intervened in the debate and ordered the council to accept surrender. It was known by everyone close to the Emporer that he was completely preoccupied with the bombing of Hiroshima, and while there were other reasons that made surrender imperative to others on the War Staff, it was the Nagasaki Bomb that pushed Hirohito in forcing the hand of the Big Six. From accounts of these meetings it is clear that they would have remained deadlocked. The Military were just not going to give up-lose face. What the Bomb did in the end, was allow the Army to say that they were not defeated by their enemy, but instead were defeated by technology.

 

Whats germane to the question of whether or not the bombs were necessary to end the war in Aug 1945, is if the US knew of the political plots and palace intrigue going on at the time.

We all know of what was going on NOW but we didn't have a clue back then. The Japanese military gave every appearance that they were going to fight on and so the US had to accept them at their word.

Some people these days make the elementary school mistake of projecting todays technological advances for intell gathering and project it upon the world 65 years ago, long before the technologies were even developed. And its even worse when the same people take six decades of material from all types of sources, US and Japanese and then say "why didnt you connect the dots"?

 

Yes, we tend to use the "lens of hindsight" without thinking of the circumstances of that moment in time. What we (Allies) knew, or thought we knew, and what they (Axis/Japan) knew and believed.

Harnessing a "force of nature", especially the "power of the universe" (incorrect, but used by Truman in his speech), against an "Empire of the Sun", ruled by a "Son of the Sun" was emotionally, politically, and militarily too much to deny as the "beginning of the end". In the minds of many religious Japanese we had captured their goddess and used her power against them. The official Japanese religion (Shinto), taught that the emperor is the descendant of the Sun Goddess Amaterasu. And as such in 1945 he was a living god and could, according to the Shinto religion control nature such as the power of the sun. Shintoism further teaches that the emperor has a duty to bring all the peoples of the world under the rule of Amaterasu a sun goddess whose power is the power of the sun itself.

This bomb, using the "basic power of the universe" made Hirohito, as her son, a fake and thus showed him and the others in the war cabinet to be without the divine mandate of the goddess. That the hated enemy now had her mandate (and power) was more than just a shock to the average Japanese; it in effect destroyed their world view and their very concept of themselves as Japanese. It wasn’t the destructiveness of the bomb itself, it was the nature of the bomb.

The Japanese would have fought the allies until they were all dead or we had gone back to the US and given up, for fighting men is easy. But how does one fight a goddess? Japan and her people, still deeply religious, believed in the goddess's mandate from heaven, without it they had no choice but to surrender.

The Japanese knew better than to fight with nature, and this was clearly a force of nature. They could fight people who invaded, fires, bullets, and the impact of conventional bombing. They could not and never did fight nature, not tsunamis, earthquakes, floods, or volcanic eruptions. Soviet entry in to the war between the two atomic explosions, helped make the decision more urgent; but as Hideki Tojo's diary states; the atomic bombs killed the god and goddess of Japan and thus forced the emperor to surrender his nation. The bombs psychological value as a weapon out weighted their destructive and killing power. With the power of their oldest goddess, the creator of Japan and spiritual mother of their emperor now in Allied hands, they knew they had no choice but to accept the terms offered to end the war.

As to clarifying the status of the Emperor post war, one must remember that the retention of the Emperor was discussed in the telegrams between Prince Sato in Moscow and Togo in Tokyo just before the July Potsdam Conference started, and continued until it was underway. We (America) were reading these telegrams in real time, and knew that Stalin was choosing to NOT recognize the Japanese attempts to broker a "peace" on their terms.

Some of which were to withdraw from occupied territories they had conquered since 1937, retain the Emperor without diminishing his authority, and hold their own "war crimes" trials, these were unacceptable to the allies.

The Japanese were insisting the Emperor retain his position and authority clear into August of 1945, a situation which the new president (Truman) was having no part of. When Stalin informed him of the Japanese attempts at arranging a diplomatic meeting, Truman wrote in his diary he was "pleased" that Stalin had told him of the Japanese communications from early July. Truman already knew of them (through "Magic") but was reassured by Stalin’s offering the information independently.

If Truman had spelled out that the Emperor could be retained in a subservient role in the Potsdam Declaration, as happened historically, the Japanese probably wouldn't have accepted that condition at that time either. Remember, the Emperor was still revered as a deity incarnate and subordinate to no mortal.

It literally took the atomics for that position to be altered to the point of all Japanese recognizing that their war was lost, and coupled with the Red Army advancing into their northern territories, they simply had to accept the demands of Potsdam if they were to survive as a people and culture.

If they hadn't then "Bull" Halsey might have gotten his wish; "When we are done with them, Japanese will only be spoken in hell." (paraphrasing I think)