Operation Crossroads: First Draft Review

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ccontamination. All drones were considered heavily contaminated until proven The exposure limit for individuals was expressed as follows in the For purposes of safety in this operation. it is considered that an Individual should not have a total exposure of over 50 or 60 roentgen in two w e e k s . If an Individual receives 10 roentgen in one day. or 60 roentgen In two w e e k s he will be withdrawn fro= active participation in the operation. The maxlmum allowable dose or tolerance for daily exposures over a long period is 0.1 roentgen. The standard of 0.1 roentgen (R) per day for long term exposure had been since 1942 in parts of matt an Engineering District and later YidePtead in the American medical commnvrity that such 'exposure was not . . permit the assuming of a calculated risk in order to let certain key personnel enter a hazardous area to make highly desirable observations when the total amount of radiation to be received is less than 10 roentgen units. This mY be permitted only on direct instructfons from Radiological safety Control. Details o f the situation and clearance therefore will be carefully logged by the accQmpanying monitor and at Radiological Safety Control- % tYPes of film badges were used at CROSSROADS. One type. called 01 mission badges, had a range from 0.05 to 2 R. !4onltOrS issued nrsn about to enter possibly radloactlve areas. The ImnltOr collected 'ho bdges the same day, after the men returned to a safe area. Each badge

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me discovery of alpha emitters, including plutonium, led to urine tests for a l l men thought exposed. The water-testing laboratory on Haven was mwt&l for testing urine. By 15 August, 1,200 samples had been tested. BY 20 August, the number approached 3,000. The men doing the work had to use what iwhich DNA (E) will wince unless it ha insttuments were on hand and develop techniques as they went. The widespread presence of radioactive material led to high background counts and - -made difficult any determination of whether an individual had alpha emitters in his urine. ADDarentlV no such individuals were identified (Reference 2. 117-118. CONTINUING NEED FOR RAO SAFE PERSONNEL Although ABLE and BAKER had been detonated and the first phase of -ROADS was drawing to a close, a need for radsafe monitors and other cadsafe personnel continued. The contaminated target and support ships Presented a relatively long-term problem, and CHARLIE, the third -test in the wmm Series, was still planned. Xoreover. the series' first phase had home to the military leadership the need for a substantial military saw a fluty of activity designed to make a start at meeting these needs. on 5 August, CJTF 1 asked the Navy Bureau of Ships (Buships) f Or loonaval officers with technical or scientific backgrounds to be assigned to tadsafe work. The officers were to be available by 1 September to begin training a i d at preparing them to take the place of the present no later than 1 November. This action was required if study of the

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This leaves one hanging, and Navy braced for law suits. What results ? FURTHIB RESEARCH NEEDED. FOLLOWUP TESTING OF PERSONNEL It seems strange that the past 40 pages refer to ShiFS, badges, etc. and this small paragraph refers to peopleOn 19 May 1947. blood counts were ordered for all Navy personnel stlll on active duty who had taken part In CROSSROADS. All those who had abnormal

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PERSONNEL DOS IME TRY i4 The Operation Plan enjoined two groups of CROSSROADS personnel to wear bdges under certain circumstances. Radsafe monitors were to wear them when ttering potentially hazardous areas. CEewmembess of aircraft airborne within f-- i mi (37 km) of the zero point from 2 hours before the detonation until 30 puts after It were all to wear badges. The Operation Plan also stated that bnltors were to provide film badges to persons entering hazardous areas aoups were heavily badged. When the radiological danger was believed to have kreased, badglng of personnel in wotklng parties also decreased, apparently bed on the judgement of the monitors and their supervisors. Eleven thousand four hundred badges were Issued at CROSSROADS and for work h the target vessels at Kwajalein through 31 December 1946. Because residual radiation from ABLE was relatively limited. badge Issue Qcreased rapidly in the days after the detonatlon even though much work was One In recovering test data and In readying the target fleet for BAKER. Date Number Issued

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From 8 July up to 24 July, the day before BAKER, between 0 and 18 badges re lssured each day (2). c r! The high and persistent levels of contamination on the target vessels allowing BAKER kept the task force at bay during late July and early August, bile efforts were made to find an effective means of decontamlnation. Badge sue during that period was as follows: Date Number Issuedr On 4 August the Director of Ship Material Issued fairly detailed nstructlons for ship decontamination (9. 4-13). The decontamination effort hen expanded and with it the daily badge issue. peaking at 245 on 9 August On 9 August alpha contamlnation was detected in samples taken from 'Unz Eusen and other target vessels, leading on 10 August to a decision to base decontamination on them (XED 185, 13). Only five badges were Issued on 1 August, and then the focus shifted to st target vessels for Wing to Kwajalein. Badge issue rebounded to an August dally peak Of 733 on

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he sixteenth. probably the result of preparations to start towing the target t i p s to Kwajalein on the nineteenth (7). For the rest of the month the trend f badge issue was downward, with only 27 issued on 31 August (2). Badge issue declined during the rest of 1946. The total for September was 45. The September days with the highest badge issues were the fourth with 27, the fifth with 100 and the tenth with 132. This probably was a reflection f efforts to moor f o r a long stay the large group of target vessels recently irrlved at Kwajalein. By the end of the month less than ten badges a day were elng issued. During October. 124 badges were issued. an average of 2.58 per lay. Eleven badges were Issued on 7 October, but the documents at hand do not indicate the reason for this upsurge in activity. Apparently the ammunition fernoval work during October did not result in extensive badging. Only 38 hdges were issued during November and only six during December (2). ' Between 37,500 and 38.000 naval personnel and about 3,100 other military nd civilian personnel participated In CROSSROADS. In addition, the operation hs observed by members of Congress, reporters, representatives of various Overnment agencies, foreign dignitaries. and sclentists. Most members of this ery large group were not badged at any time during CROSSROADS. Because onitors usually issued badges for a given mission only, some portion of those ho were badged received more than one. The number of individuals receiving adges is not presently available, but the uavy estimates that about 15 ercent of Its personnel received at least o n e badgei ( 5 ) . The badge readings were entered rd government green ledger M k s along with certain associat n. Each hand-written entry sually included the number imprinted on the piece of film in the badge, the- * - +

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e highest recorded Navy exposure was 2.03 R. The highest badge r d p i n g for eEven use of supplemented exposure records leaves Investigators facingc vera1 major obstacles In obtaining a picture of the radiological exposure of rsonnel at CROSSROADS: 1. Low percentage of personnel badged 2. Chronic use of only last names to Identify badge wearers 3. Apparent distribution of badges such that a small group exposed to radiation -- the radsafe moni tors -- frequently received badges, while two larger groups also exposed to radiation -- the men in the working parties and the crews of the support ships -- seldom 4. Lack of records on who was In many of the working parties entering the contaminated area to recover data and to decontaminate and make repairs on the target' ships 5. Relatively low-level but widespread contamination of the support ships after BAKER. To produce estimated doses for all CROSSROADS participants, a dose hconstructlon project has been completed. In this effort, three major sources 'E radiation were considered: 1. Contamination of lagoon Waters with fission fragments unspent plutonium. and neutron-Induced radioactivity,

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2. Target ships as radiators, resulting from fallout andi .' 3. Contamination buildup on ships operating in the With a computer-mounted mathematical model, curves to measure an estimated lose for each ship have been created. The model uses information about the hip's movements, about the radiation fields through which i t passed, and h u t the contamination it collected. An estimated dose can be calculated up 10 the time the ship was granted final radiological clearance after BOSSROADS. In order to estimate the total dose for an individual who was &signed to recovery parties and/or decontamination working parties, it Is wessary to know the time and location of these activities. In many cases hat level of detail is not available. The discovery of alpha contamination on Prinz Euuen and other target ships 30an end of e f f o r t s at Bikini to decontaminate the target ships. The task 3rce leaders apparently feared that the alpha emitters posed a significant lhalatlon and lnjestlon hazard to working party personnel. This concern mtinued through the efforts at San Francisco Naval Ship Yard to develop Thods for decontamlnatlon of the support ships and standards for their final earance. In spite of this concern, no alpha contamination measurements made Bikini are now available. Some data on alpha contamination of task force ips gathered at San Francisco is available. Samples taken from : USS Laffey (DD-724) allowed determination of a plutonium-fission product l o . but the plutonium contamination Is not given as such. USS Rockbridue

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A-228) was found to have enough plutonium to constitute several tolerance es, mostly In the saltwater system and on the underwater body (XRD 185, 32 d 56). The USS Crlttenden (APA-77). a target ship, showed 0.045 alpha counts r second at Its most contaminated location. It was calculated that a worker h breathing apparatus would have to work 220 days at that spot to accumulate he then accepted tolerance dose - 0.1 R micro (3). The extent of the i$OSSROADS dosimetry and the form In which It was recorded seriously limlt its -5efulness In appraising the exposure of personnel. A better picture of the i$posure can be obtalned by the use of the reconstructed doses curves. Information I s lacking on whether all personnel going aboard target tssels at Kwajaleln were badged before 31 January 1947, but on that date the h e f of Bureau of Medlclne and Surgery ordered that all members of boardlng bttles wear badges (6, 4-51. After 6 October 1946, 401 Individuals were Ldged, with a mean gamma reading of 0.245 R and a mean beta reading of ndlvldual had 12.6 R beta and 1.47 R gamma (4). F Very much vital info is missing: Who produced badges? Describe them, including beta window:. What about disaster badges?