Castle BRAVO at 70: The Worst Nuclear Test in U.S. History

The weather briefing in advance of the Bravo test demonstrated the military’s overconfidence that there was no fallout risk. The forecast estimated “resultant winds in the direction of Rongelap and Rongerik” but the distances involved “compared to the resultant wind speeds were such that no fall-out would reach those atolls.” The “long time of travel for fall-out to these places,” some 12 to 15 hours after the test, would protect them from exposure.

The first message was received in garbled form but referred to “heavy fallout” from the Bravo test, provided readings of radiation levels, and described damage to U.S. sites in Bikini Atoll. A message from 2 March mentioned “heavy contamination” and a preliminary yield estimate of 15 megatons “plus or minus 5.” Radiation levels at Rongelap were “apparently sufficiently high to warrant evacuation of population,” but there “was no indication that a serious health hazard exists.” A message from 6 March indicated approval of Project 4.1 [See Document 8] and reported that people evacuated from Rongelap “are believed to have received 130 roentgens,” with 0.1 roentgen per day accepted then as an upper limit for full-body exposure to ionizing radiation.

With “heavy fallout to the east of Bikini,” the Task Force reported planned evacuations to Kwajalein: 20 Weather Station personnel, 100 people from Rongelap and 170 people from Utirik. Those with “highest exposure” would be sent to Majuro. Film badges worn by Air Weather Station personnel showed exposure at 40 roentgens with the exception of 98 for one person, although none of them became sick (having been ordered to stay inside to minimize exposure).

This report covered radiation readings at Rongelap Atoll, the monitoring of Utirik Atoll, and the evacuation of U.S. personnel from Rongerik Atoll. Reports on evacuation from Rongelap had not yet arrived while the evacuation from Utirik had already occurred. The commander proposed a press release on the evacuation of 300 people from Rogerik and Utirik to Kwajalein atoll as a “precautionary measure in order to preclude the possibility of their exposure to any radiation hazard incident to the detonations of the current test series.” No such statement was made until 11 March when the AEC’s hand was forced. [See Document 9]

U.S.S. Phillip Commander G. W. Albin reported the evacuation of the atolls with lists of the people evacuated, radiation readings, and a map of wells sampled for radiation. “On the basis of initial readings it appeared obvious that evacuation was definitely in order.” The average for Rongelap was the terribly dangerous level of 1,473 mR (milliroentgen) per hour with a maximum reading of 1,900 mR/hr. After meeting with Rongelap Magistrate John Anjain, and with interpretation provided by Oscar DeBrum, Albin persuaded the people that they had to leave, with “each person … asked to bring a small handbag as the only baggage since the monitors readings indicated a high dosage on sleeping mats, palm baskets, and other personal belongings.”[12]

With the AEC’s 6 March request for reports on the condition of “natives,” officials in Kwajalein reported on 10 and 15 March, various symptoms, white blood cell counts, and radiation readings. The “prognosis of Rongelap group depend[s] upon further studies.” The “natives … are comfortable.” According to the 15 March report, the Utirik group “shows no evidence of any sort of over exposure to radiation,” while the Rongelap group “shows definite laboratory evidence of mild radiation injury as demonstrated by modest decrease in white blood cells.” The 15 March message reported that, “These residents received approximately 125 roentgen cumulative.” For the 28 personnel from Rongerik, the “blood picture [was] reported to be similar to Rongelap group.” There was “no evidence of beta burns,” and the “estimated total body exposure” was due to gamma radiation. But that soon proved incorrect when “severe” beta burns appeared. Members of the Joint Congressional Atomic Energy Committee visiting Kwajalein, Senator John Pastore and Rep. Chet Holifield, believed that displaced residents were “well taken cared for” and in the “highest spirits.”

With reports of heavy fallout coming in, U.S. Navy medical officer Eugene Cronkite was tasked to lead a study of “response of human beings in the Marshall Islands who have received significant doses due to the fall-out from first detonation of Operation Castle.” Designated project 4.1, the project’s title was a “Study of Response of Human Beings Exposed to Significant Beta and Gamma Radiation Due to Fallout from High Yield Weapons.” Secrecy was the project watchword: “Due to possible adverse public reaction, you will specifically instruct all personnel in this project to be particularly careful not to discuss the purpose of this project and its background or its findings with any except those who have a need to know.”

Questions have been raised about Project 4.1 and the programs that followed, especially whether they were driven more by military research objectives than therapeutic assistance to the people of Rongelap and others in the area exposed to radiation. A key problem was the failure to ask the research subjects for their consent.[13]

In letters sent home to his family in Ohio, a U.S. Marine stationed in Kwajalein wrote that the Bravo test had shaken buildings and that two destroyers had pulled in to the port with “natives … suffering from various burns and radioactivity.” A Cincinnati paper quoted the letters, and the story went out over the Associated Press, forcing the AEC to issue a statement about “routine atomic tests” and noting that U.S. personnel and Marshall Islands “residents” had been evacuated “according to plan as a precautionary measure.” As historian Barton Hacker later observed, while the press release “nowhere misstated facts,” it was “misleading and disingenuous throughout.”[14]

The reports from mid-March showed that officials had concluded that “in view of the contamination levels at Rongelap and the exposure already experienced by the natives from that atoll, it would be unwise to return them for at least 60 days after evacuation.” One report compared the effects of radiation on the Rongelap people to those suffered by the Japanese in August 1945: They “correspond very well from a blood picture standpoint to Japanese groups . . . who were about 1.5 miles from ground zero” in which “2 to 3 percent lost some hair, 10% had sore mouth, and 5% had hemorrhages under the skin.” A report from a month later noted an “increase in white blood cell and platelet counts which indicates that maximum effect of radiation damage has been seen and that regeneration is taking place.” In addition, “most of the skin lesions are subsiding and few new cases are being seen.” Thus, the beta burns that had not been seen in early March had appeared and were healing.

Significantly underestimating the health effects and radiological consequences of the Bravo test, an official with the AEC’s Division of Biology and Medicine estimated there will be “no deleterious, long-run effects on the physical well-being of the native inhabitants.” Moreover, “the fall-out that occurred did not damage the land in the sense that it could not be reinhabited or could not be used for agricultural pursuits.” Besides the uninhabited islands of the northern part of Rongelap Atoll, “all the islands could be re-entered safely in the near future.”

Discussing the news of radiation injuries to the Lucky Dragon crew, the Commission agreed to send instructions to Ambassador Allison in Tokyo. Dr. John Morton of the Atomic Bomb Casualty Commission was to report to the Ambassador to volunteer the support of the ABCC. No other countries would have access to the ship. The Commission asked Colonel Vincent Huston to obtain “precise information regarding the decision as to what constitutes the danger zone and what warning had been posted to shipping.” Commissioner Thomas Murray “said that he wished to emphasize the importance of preventing access to the vessel because of the information that might be gained from ash samples.” Murray was no doubt concerned about Soviet access, direct or indirect, but as far as sensitive information being gained from the fallout, Japanese scientists were analyzing it and discovered important elements of the Bravo design.[15]

When the Fukuryu Maru returned to port at Yaizu on 14 March, the secret of Castle Bravo’s fallout effects was out. The Japanese government informed Washington about the condition of the crew, and State Department and Atomic Energy Commission officials immediately began discussions of liability issues, probable Japanese claims, and compensation. After some consideration of using emergency funds available to the State Department and the White House, it became evident that the Bureau of the Budget would play a central role in making recommendations for compensation.

Despite subsequent claims to the contrary by AEC chair Lewis Strauss, the Fukuryu Maru was operating 14 miles outside the 57,000 square mile “Danger Area” established by the U.S. Navy around the test site. The crew had no warning that a test was imminent, and U.S. radar and spotter planes did not detect the ship. The “Danger Area” had nothing to do with health and safety; rather, it was a security zone “to deny information to enemy nations.” After the Fukuryu Maru incident became known, the U.S. Commander-in-Chief Pacific created a much larger danger zone of 570,000 square miles, which raised serious problems for the Japanese fishing industry.

This and the two telegrams that follow illustrated the extent to which the precarious health situation facing the Fukuryu Maru crew and the deep aversion to nuclear weapons among the Japanese raised difficulties for U.S.-Japan relations. Arguing in support of compensation for the damage done to the fisheries and the health effects suffered by the crew of the Lucky Dragon, Ambassador John M. Allison recognized that the Japanese government was in a difficult position, facing, as it did, questions about the U.S. closing off massive areas of the Pacific and the impact on the fishing industry. Perhaps not sufficiently appreciating the Japanese government’s difficulty and the U.S. responsibility for the crisis, the Embassy reports were critical of a perceived lack of cooperation on Tokyo’s part.

Allison recounted his conversation with Foreign Minister Okazaki and the latter’s concern about the deterioration in U.S.-Japan relations.

Allison reported on what he saw as a decline in U.S.-Japan cooperation over access to the Lucky Dragon crew and the sources of the problem. Sensitive data on radioactive fallout had reached the Japanese press, which was “fanning extreme emotionalism,” for example by claiming that the U.S. sought to use the patients as “guinea pigs.” Moreover, Japanese Communists were trying to capitalize on the affair. Besides an “irresponsible” attitude on security, the Embassy also saw bureaucratic rivalries and the “resentment” of Japanese scientists complicating U.S.-Japanese relations.

The publicity about Bravo and a perceived need to “to ease fears” led the White House to hold a press conference featuring AEC chair Lewis Strauss, but what he said may have had the opposite effect.[16] A few days earlier, when speaking with Secretary of State Dulles, Strauss denied reports about the Bravo test, saying, “Nothing was out of control. Nothing devastated.” But Dulles took exception, saying “that was not correct from our point of view.” Concerned about Bravo’s “repercussions,” Dulles saw a “general impression around the world [that] we are appropriating vast area of the ocean for our use and depriving other people of its use,” “panic” about contaminated fish, and fears among allies that “could lead to a policy of neutrality or appeasement.” Dulles’ reproaches did not persuade Strauss, who doubled down at the press conference by denying that the effects were “devastating” or “out of control.”

At the press conference, Strauss spoke at length about nuclear testing, and one of his statements produced alarming headlines the next day. When reporter Richard Wilson (Cowles Publications) asked him to “describe the area of the blast, the effectiveness of the blast,” Strauss hesitated, then said that, while the specific megatonnage of the detonation was secret, an H-bomb could be “made large enough to take out a city.” The transcript describes the response from the room as “(A Chorus of ‘What?’)” to which Strauss said, again, “To take out a city, to destroy a city.” Asked by United Press reporter Merriam Smith: “How big a city? … Any city, New York?” Strauss answered: “The metropolitan area, yes.” At that point, according to Eisenhower Press Secretary James Hagerty, “All hell broke lose.”[17]

Strauss also made several misleading statements about the Bravo test, its radiation effects, and the Lucky Dragon incident. While admitting that Bravo was a “stupendous blast in the megaton range,” he declared that its “yield was about double that of the calculated estimate -- a margin of error which, I submit, is not incompatible with a totally new weapon.” Yet, the yield was almost triple the estimate, and its explosive force and fallout were well outside of any reasonable “margin of error.” Furthermore, after claiming that the evacuated Marshall Islanders were “well and happy” on Kwajalein, Strauss said that the irradiated Lucky Dragon “must have been well within the danger area,” when in fact it was not. He also alleged that the injuries to the crew, such as the skin lesions, were “thought to be due to the chemical activity of the converted material in the coral rather than to radioactivity.” Strauss refrained from saying what he had told others: that the Lucky Dragon was a “Red Spy Outfit.”[18]

The audio recording of the press conference has never been digitized and is presented here for the first time.

Merril Eisenbud, the AEC’s top health and safety official, arrived in Tokyo on 22 March to investigate the irradiation of the ship, the cargo and tuna catches, but also to offer technical support, mainly on radiological issues, to the Japanese scientists and doctors treating the crew. Dr. John Morton, the director of the Atomic Bomb Casualties Commission, had already offered assistance in treating the patients. Eisenbud’s report cited the “uncooperative atmosphere” that he encountered, such as Morton’s inability to get access to most of the patients and the general refusal of the Japanese to provide access to all but small portions of the radioactive ash that had been collected.[19]

Eisenbud’s preliminary report reviewed issues that he believed needed further exploration, including the degree of dangerous beta and gamma radiation that the fisherman had received from the fallout. Noting estimates that exposure had been in the range of 70 roentgens, Eisenbud believed that the “actual dose could have been 2, 10, or even a 100 times higher.” Later research indicated that the crew had been exposed to 290 roentgens, whereas 3.9 was the maximum allowable exposure for AEC personnel.[20]

This report does not mention Eisenbud’s visit to Yaizu, the Lucky Dragon’s home port (although it may be covered in other records). During the 1967 interdisciplinary conference on “selected effect of general war,” Eisenbud recalled that during the visit the mayor invited him to the hospital where he saw some of the crew members, “made enough very superficial measurements to ascertain that their thyroids were very hot,” and “took samples of their hair and asked for some skin scrapings, which … were sent to New York and analyzed subsequently.” [See Document 43].[21]

This AEC chronology illustrated the deteriorating U.S.-Japan relationship during the weeks after the Lucky Dragon incident. The ABCC’s offer to help treat the crew created suspicion in Japan because of its image as a research organization that did not provide treatment. Suspicion that the ABCC would use the crew members as “guinea pigs” mounted while a leading Japanese expert on radiation, Dr. Masao Tsuzuki, said that Japan was a “victimized country.” ABBC doctors sought to examine crew members and their medical information, and Foreign Ministry officials were avowing to “do their best” to make that possible, but wary hospital officials limited access and only permitted Dr. Morton to make a “friendly” visit to seven of the fishermen. Moreover, the U.S. refused to provide information about the Bravo device, although the Japanese believed that such details could help provide better treatment. The Japanese eventually provided some access to a few crew members and some medical information, such as blood counts, but it was far less than U.S. officials sought. On the Japanese side, as M. Susan Lindee has noted, the interactions with the ABCC “became symbols of further Japanese victimization and American inhumanity.”[22]

After Japanese doctors had issued public reports about the deteriorating health of the fishermen and had publicly requested information on treatment to remove radioactive Strontium-90 from bone marrow, angry U.S. Embassy officials demanded that the Japanese government correct statements suggesting that the U.S. had been uncooperative. In the wake of this incident, YWCA president Uemura publicly protested to President Eisenhower’s wife, Mamie Eisenhower, asking why the U.S. government had questioned the doctors’ statements, suggesting a lack of understanding about Japanese thinking about the horrors of radiation sickness. Uemura highlighted the serious damage the tests had inflicted on the fishing industry since fish was a “must item” in the Japanese diet.[23]

The U.S. Embassy reported that the Japanese Foreign Ministry had sent a note trying to explain why the Japanese reaction to the incident had been unfavorable to the U.S. and why Tokyo had found itself in an “embarrassing” position during the crisis. For example, information on the composition of the fallout had been reported publicly because Japan had no atomic secrecy regulations, and U.S. doctors had not received full access to the patients because of concern that they would be seen as “experimental material rather than as a therapeutic object.” The Embassy rejected the latter claim but agreed about the “poor figure [the] Japanese government has cut throughout incident.”

The Department sent the Embassy in Tokyo a recent report from the AEC’s Division of Biology and Medicine based on urine samples of some of the crew and blood counts provided by the Japanese. The news was bad: the urine samples showed that radioactive material had been “ingested” and the low white blood cell counts of the “most seriously affected patients” made it “unwise to assume at this point that all will recover.” A draft statement on the possible death of a crew member was being prepared, and a copy of the AEC report was being made available to the Joint Committee on Atomic Energy, which had been asked to hold the information close because publicity would have “unfavorable repercussions.”

A Food and Drug Administration official reported to the State Department that a West Coast cannery had discovered three radioactive tuna imported from Japan since 1 March. The tuna had probably eaten contaminated fish because the skull and bones of the fish were radioactive. For the time being, and to keep the information under control, the Department would not inform the Embassy in Tokyo, and presumably Japanese diplomats would not be told either.[24]

Ambassador Allison reported that Prime Minister Yoshida had almost been persuaded to request a $4.2 million compensation claim, but that the Foreign Ministry had talked the number down to $1 million. Allison favored a quick settlement to avoid adverse publicity, but it took months to finalize, even after one of the crew members, Aikichi Kuboyama, died in September 1954 from liver ailments possibly aggravated by the radioactive exposure. The U.S. government gave his widow a check for 1 million yen ($2,800), and in January 1955 it paid the Japanese government $2 million in compensation for losses caused by BRAVO and other tests.[25]

Tokyo kept up the pressure on Washington on various fronts. A note from the foreign minister requested that the U.S. move its nuclear testing grounds as far away as possible, but if that could not be done, to reduce the size of the tests. The matter of compensation to the Japanese fishing industry for damage caused by nuclear testing also remained on Tokyo’s agenda.

Castle Bravo and its consequences sparked antinuclear protests around the world, raising concerns that Washington was carrying out racist policies. Calling for a “standstill agreement” on nuclear tests, Indian Prime Minister Jawaharlal Nehru said it was “of great concern to us that Asia and her peoples appear to be always nearer occurrences and experiments, actual or potential.”[26] The Joint Chiefs of Staff quickly rejected proposals for a moratorium, arguing that, with the U.S. already enjoying an “indeterminate advantage” over the Soviet Union in nuclear weapons technology, a moratorium would provide Moscow with the opportunity to “neutralize” the U.S. advantage by abrogating or violating an agreement. While a moratorium might be politically advantageous for Washington, the advantages would be fleeting, “whereas the military disadvantages would be far-reaching.” While U.S. officials came to believe that the fallout from atmospheric testing was a tolerable risk, by 1963 it became politically necessary to ease public apprehension by accepting the constraints of a limited test ban.[27]

On 20 April, representatives of the Congress of the Marshall Islands filed a petition with the United Nations. Citing the “increasing danger” from U.S. nuclear tests in the area and the suffering of the people of Rongelap and Uterik, the petition declared that land and access to it were the basis of the “very life of the people.”[28] Therefore, the petitioners asked for a halt to nuclear testing in the area, but if that was not possible, for the United States to take “all possible precautionary measures” and to provide safety instruction for the inhabitants and compensation for losses.

A response prepared by the AEC and the State Department conceded the suggestions were “eminently reasonable” but also claimed the nuclear tests were in the “interests of general peace and security.” Misleadingly, they declared that the Marshall Islanders “had no medical reason to expect any permanent after-effects on the general health of the inhabitants.”

Merchant reported that during British Ambassador Roger Makins’ meeting with Secretary of State John Foster Dulles they discussed a “possible moratorium on H-bomb experiments.” At first, Dulles had been interested in the moratorium concept but he had become doubtful about the “wisdom” of a standstill because it “might handicap us in the missile field” (a probable reference to the U.S. search for lighter nuclear weapons), “impair the spirt of enterprise” among scientists, and “boomerang from a propaganda point of view.” Dulles explained what he meant by that during an NSC meeting a few days later: the U.S. moratorium proposal “assumed that we would continue to be free to test weapons of this or lower yield, but if we propose the 100 KT as the lower limit, the Soviets might well come back with a proposal to ban tests of all weapons yielding more than 50 KT.”

When the AEC’s General Advisory Committee (GAC) met at the end of March 1954, it heard some reports and discussion of the Bravo shot and its impact. One of the attendees, Dr. Charles Dunham, director of the AEC’s Division of Biology and Medicine, acknowledged that some Lucky Dragon crew members were in “critical condition” and “some fatalities might be anticipated.” The AEC’s Director of Military Applications General Kenneth Fields spoke in detail about the fallout. Given the radiological mess created by Bravo, he said he was “convinced that these large weapons should not be shot unless there was very good insurance of getting a lot out of the test.”

This and the other available minutes of the AEC’s General Advisory Committee (GAC) during the aftermath of Castle Bravo (Document 35) remain heavily excised. The original records are at the National Archives and further declassification reviews have been requested.

This report by the Armed Forces Special Weapons Project was one of the earliest comprehensive studies of Castle Bravo. Although the test took place on a coral reef, the report said it constituted a “unique opportunity to gain at least partial documentation of fall-out radiation effects from a large yield weapon burst under conditions at least approximating a land-surface detonation.” One of the report’s major findings was that the “land surface detonation of a 15 megaton yield weapon can be expected to deposit radioactive fall-out over an area of the order of 5,000 square miles or more in such intensities as to be hazardous to human life.” Without the taking of “passive defense measures, fatalities in that area would be 100 percent.” Thus, survival would depend on taking shelter and evacuating contaminated areas after ten days when it had become safer. This made radiation danger “a primary anti-personnel effect”—one of the panoply of weapons effects that defense planners could take into account when assessing the destructiveness of high yield, multi-megaton H-bombs.

The detailed transcript of this meeting is at NARA but has not yet been declassified. According to this precis of the meeting, General Fields reported on the development of thermonuclear weapons with explosive yields ranging from one quarter to 20 megatons. Using some of the results of the Bravo tests, Fields projected the destructive impact of a 15-megaton weapon detonated at “zero point” on Washington, D.C.

According to a history of the Atomic Energy Commission, Fields’ briefing was “frightening.” The book provided this summary: “If Bravo had been detonated at Washington, D.C., instead of Bikini, Fields illustrated with a diagram, the lifetime dose in the Washington-Baltimore area would have been 5,000 roentgens; in Philadelphia, more than 1,000 roentgens; in New York City more than 500, or enough to result in death for half the population if fully exposed to all the radiation delivered. Fallout in the 100-roentgen area, which might have been roughly comparable to the Lucky Dragon exposures, stretched northward in a wide band through New England toward the Canadian border. This diagram was classified secret and received very little distribution beyond the Commissioners.”[29]

This declassified letter by GAC chair Isidor Rabi suggests how concerned the members of the Committee were about the fallout effects that “Shrimp” highlighted. The Committee had recently requested an interagency study of the “longer-range problem of what would happen to the environment, and to plant and animal life, which had been subjected to intense fall-out amounting to 500 roentgens in 50 hours over an area of approximately 5000 square miles, as occurred over the Pacific in the Shrimp test.” Rabi observed that it was “hardly necessary to point out the importance, and our present high degree of ignorance, of this problem.”

This highly excised report provides little detail on the Castle series, but some of the conclusions come through: for example, that the tests demonstrated the “achievement of an emergency capability on at least one weapon” and the possibility of “further development in the direction of weight reduction of thermonuclear weapons.” Moreover, “more radioactive debris was carried up and diffused over a much larger area than was thought possible.” The contamination caused by the Bravo shot indicated that previous testing had failed to collect fallout information. The experience of evacuating inhabitants and U.S. personnel from some of the Marshall Islands was “valuable in evaluating radiological safety conditions on subsequent shots so that no additional significant contamination of populated areas occurred.”

This record of the July 1954 GAC meeting includes interesting details on the Castle Bravo test, including that the “predicted yield” of the detonation was four to eight megatons (p. 11). It also includes weapons designer Carson Mark’s explanation of why “the yields of the Castle shots were substantially higher than predicted in most cases.” It was the role of lithium-7, he explained: the higher yields were “now understood in terms of the nuclear reactions of lithium-7, which had been assumed to be a much less good fuel than lithium-6 or liquid deuterium.” During this meeting, the GAC also heard a briefing on nuclear weapons effects, such as the “bonus” destruction caused by using a megaton instead of a kiloton weapon “due to the longer wind duration with the higher yield explosion” (p. 7). Other topics of discussion included the thermonuclear weapons program, the weapons use of “dirty plutonium,” weapons test programs, physicist John Von Neumann on “Air Force attitudes,” and missile applications.

This U.S. Air Force report analyzed the military implications of the massive downwind fallout and “horrible” levels of casualties that would be caused by radiation on the scale of that produced by the Bravo shot. Positing that such multi-megaton weapons were usable in general war, Lulejian suggested military measures and countermeasures. For example, he recommended surface bursting of such weapons to “reduce the worldwide contamination,” arguing that “80 to 90% of the total residual activity is deposited on the enemy country if the bomb is surface burst, thus leaving only 5 to 10% for contaminating the rest of the world.” That was optimistic, indeed, if, for example, nuclear weapons dropped on Leningrad could seriously contaminate nearby countries such as Finland. He also suggested that the huge blast areas produced by high-yield weapons could make it “possible to relax the CEP [Circular error probable] of intercontinental missiles.” By lessening accuracy requirements, the U.S. could “wage atomic warfare using ballistic missiles which are intended merely to hit certain areas of the enemy country.” Instead of destroying specific cities or installations, the U.S. could destroy designated areas.

Tables 11 and 12 (PDF pages) superimposed upon the northeastern U.S. the fallout from the first Castle test during the first 48 hours, showing “that there was no place to hide.” These diagrams may have corresponded to ones used by General Kenneth Fields in his briefings to the AEC and other organizations during May 1954. According to the report, “an unprepared and an uninformed nation will suffer horrible casualties from radiation.” Yet, “by relatively simple means (proper education, early warning, shelters, etc.) it may be possible to reduce significantly the radiation casualties throughout the nation.’’

Concern about the public health effects of radioactive fallout produced by atmospheric tests, especially the impact of Strontium-90, led to the creation of Project Sunshine in 1953. Its name notwithstanding, it was secret until 1956 when AEC Commissioner Willard Libby, who was a leading figure in Sunshine, revealed its existence, although not the fact that the research had utilized human bones partly from stillborn babies.[30] With this memo, Col. Lulejian sent Libby his report on atomic warfare radiation hazards. The memo is excised in key passages, but Lulejian’s major point is clear: that he believed that his new study of Bravo fallout demonstrated that “SUNSHINE underestimated the Sr90 hazard”—that is, levels of radioactive debris produced by testing that could contaminate plant life, dairy cows, mothers, and their babies were higher than had been assumed.

Using 18 ground monitoring systems and Navy patrol planes, the AEC was able to measure peak and cumulative radiation doses on the atolls. Because the Bravo shot produced the most extensive fallout, it “accounted for 89% of the total cumulative radiation measured during the program.” Data on Bravo was incomplete, in part because of the removal of the automatic gamma monitor from Rongerik with the evacuation from that site. Not surprisingly, “The greatest radiation rate, extrapolated from direct measurements, 12.5 r/hr, occurred at Rongelap after Bravo.” With the outsized impact of Bravo, “the greatest estimated cumulative radiation occurring from any event … was 190 r at Rongerik,” where the total cumulative radiation, with all of the Castle detonations taken into account, was 206 roentgen.

The report included recommendations for improving data collection, such as the installation of battery-operated, unstaffed equipment on the atolls and the essential need for duplicate equipment at unstaffed stations. The alternative to battery-powered equipment would be “more frequent flights covering more flight patterns” after a test, although instruments on the ground would provide more precision information on the arrival of fallout.

Wadsworth recounted a recent memorandum from Mason Sears, the U.S. Representative to the United Nations Trusteeship Council, to Ambassador to the United Nations Henry Cabot Lodge about the diplomatic risks posed by the post-Bravo situation. Noting that India’s representative to the UN, Khrishna Menon, had raised questions about the legality of nuclear testing in UN trust territories, Sears argued that Washington would have trouble getting the support of close allies if another Bravo incident occurred. Moreover, Washington had to move forward on the matter of compensation; the claims of the Bikinians remained unresolved, and “just and prompt settlements” for the former residents of Rongelap and Uterik were also necessary.

Taking into account Sears’ argument for compensation [See Document 39], Lewis Strauss described the state of play in this letter to the Secretary of State. A lump-sum payment was in the works for the Bikinians who had been displaced in 1946. Strauss misleadingly claimed that people on Rongelap and Uterik had been evacuated “immediately” after the test, but that did not occur until two days later and after huge amounts of radioactive debris had fallen on the atolls. With respect to their claims, the Defense Department would handle them, but they had to be filed within a year of incident. The people on Uterik had already returned to their homes, and the Rongelap people were to be returned in May 1955, by which point, Strauss maintained, the “residual level of radioactivity will decay to insignificance.”

Bikini's former inhabitants received compensation in 1956, but it was not until the mid-1960s that the U.S. government provided any compensation for victims of the Bravo exposures. It took another 24 years for Washington to establish a trust fund for the Marshall Islands.

Strauss’s hope for a return to Rongelap atoll by May 1955 was excessively optimistic. By April and May, discussions between AEC and State Department officials indicated that immediate return was impossible. The initial conversation indicated serious problems: people could go back to the atoll as long as they “restrict” themselves to the southern islands and “do not eat too many shellfish,” an extreme limitation on people that relied on seafood as a primary protein source.

In mid-May, Deputy High Commissioner for the Pacific Islands Trust Territory Delmas Henry Nucker decided that returning to Rongelap “would still be dangerous to the inhabitants, as would the shellfish in the lagoon.” It would take “another year” before the atoll was “completely safe for the people to return.” In 1957, people returned to Rongelap, but the area remained seriously contaminated. Controversy over the actual impact of the radiation persisted, but growing concern about the degree of hazard led the people on Rongelap to vote with their feet. In 1985, Greenpeace’s Rainbow Warrior transferred over 300 people from Rongelap to Majetto, an island in the Kwajalein Atoll.[31]

Thirteen years after the Bravo shot, the Defense Atomic Support Agency (one of the predecessors of the Defense Threat Reduction Agency) sponsored an interdisciplinary conference in October 1967 on “selected effects” of “general war” that brought together specialists in genetics, radiation biology, nuclear weapons, physics, and pathology, among other disciplines. Several participants were directly involved in the aftermath of Bravo, either in Japan or in the Marshall Islands, including Merril Eisenbud, Robert Conard and Charles Dunham. Other participants, such as Stafford Warren, had played an important role in the Manhattan Project, while Theodore “Ted” Taylor had been a weapons designer at Los Alamos and was becoming increasingly critical of nuclear weapons.

In his recent book, Blown Away, Walter Pincus provided a fascinating discussion of this conference, including his finding that participants agreed that the U.S. government officials had “not told the truth initially about what happened to the Marshallese after Bravo, nor had they been honest about the impact of radioactivity in fallout.”[32] To such points, one of the participants, Frank Fremont-Smith of the New York Academy of Sciences, observed that “every government gets caught in this kind of thing or is in danger of getting caught in this kind of thing. But the first thing to do on the government’s part is to deny that anything dangerous has happened, which is almost standard procedure, and then gradually it leaks out, whereas actually this is the way that people lose faith in the government.”

Merril Eisenbud spoke pointedly about the repercussions in Japan of the Strauss press conference, noting that it included statements that “were very offensive to the Japanese and that caused things to deteriorate so far as [Dr. John] Morton and myself were concerned.” One was Strauss’s claim that that the burns on the Lucky Dragon crew were “not due to radiation but … to lye produced when the coral was calcined in the fireball and then fell out on the fishermen.” The other was Strauss’s statement that the Lucky Dragon was inside the danger zone. Eisenbud stated that “this coming straight from the horse’s mouth, so to speak, [was] widely publicized, nationally televised, and presumably [was] an authoritative statement, [and] made it very difficult for John Morton and me to be effective any longer.”

This comprehensive work on the Bravo shot was written for a highly specialized audience, although the fine selection of photographs are of interest. One of the purposes was to explain exactly how local populations in the Marshall Islands were exposed to dangerous levels of fallout. The “misleading” lessons of the Ivy Mike test fed into the analysis, along with the fact that the explosion occurred on sand and coral. Thus, the authors sought to lay to rest the “legend” that unanticipated shifts in the wind led to the fallout on Rongelap [See Document 15B for an example]. While the report challenged the finding that radiation was responsible for thyroid problems among the Marshallese, it included this sobering conclusion: “It is clear beyond doubt that the people evacuated from Rongelap, especially the children, have suffered medically from their fallout radiation exposure.” [p. 120]