Fact Sheet: Operation Redwing

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Sheet Defense Nuclear Agency Public Affars Off Ice REDWING was a 17-detonation nuclear weapon test series (see table) held at the Atomic Energy Commission’s (AEC) Pacific Proving Ground (PPG) in spring and summer 1956. The PPG consisted principally of Enewetak* and Bikini atolls in the northwestern Marshall Islands in the Central Pacific Ocean. REDWING test events, 1956a Name Location (local time) Enewetak; surface on Runit Island Bikini; airdrop near Nam Island Bikini; surface on Eneman Island Enewetak; tower on Aomon Island Enewetak; tower on Runit Island Enewetak; surface on Boken Island Bikini; barge of Iroij Island Enewetak; tower on Runit Island Enewetak; tower on Aomon Island Enewetak; airdrop over Runit Island Enewetak; tower on Lujor Island Bikini; barge off Iroij Island Enewetak; tower on Eleleron Island Enewetak; barge off Dridrilbwij Island Bikini; barge off Iroij Island Bikini; barge over Nam Island reef Enewetak; barge off Dridrilbwij Island ZUNI (3.5 MT), SDIINOLE (13.7 KT), TEWA (5 MT). one kiloton equals the approximate energy release of the explosion of one thousand tons of TNT; one megaton equals the approximate energy release of the explosion of one million tons of TNT. *The spelling of Marshall Island place names has changed in rE!Cf211t yf2arS in order to more accurately render the sounds of the Marshall Island names using

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The REDWING series was held primarily to test high-yield thermonuclear devices that could not be tested in Nevada. The development and testing of these devices, which generate their explosive power through the fusion or joining of hydrogen atoms, began in 1950 and had advanced to the stage that one of these was dropped from a B-52 bomber in REDWING. This test drop, although of some scientific interest, was probably more a demonstration to the world of the deliverability of these weapons than an experiment. The drop was witnessed by a group of U.S. newsmen, the first such group invited to view a Pacific nuclear test since 1946. The devices were tested at the PPG by a joint military and civilian organization designated Joint Task Force 7 (JTF 7). This was a military organization in form, but was populated by military personnel, Federal civilian employees, and contractor personnel of the Department of Defense (DOD) and the AEC. The commander of this force was the appointed representative of the AEC and reported also to the Joint Chiefs of Staff (JCS) and the Commander in.Chief, Pacific (CINCPAC). The peak DOD numerical strength of REDWING was approximately as follows: DOD civil service 600 Total DOD personnel 10,450 In addition, several thousand men from the AEC and its contractors, a few from other Government agencies, and some foreign observers were present. Numerous technical experiments were carried out in conjunction with each of the 17 detonations. These experiments measured the yield and efficiency of the devices and attempted to gauge the military effects of the explosions. DOD personnel participated in this test operation as individuals whose duty stations were at the AEC design laboratories, as units performing separate experiments, and as units performing various support roles. The REDWING operations placed most of the Navy support group at Bikini, where its ships ~rovided livinq space for ~ersonnel who were evacuated from the islands An extensive radiological safety (radsafe) program was instituted whose objectives 1. Maintenance of personnel radiation exposure at the lowest possible level consistent with medical knowledge of radiation effects and the importance of the test series. 2. Avoidance of inadvertent contamination of populated islands or transient shipping. The program established an organization to provide radsafe expertise and services to the separate components of the task force who were responsible for personnel safety within their commands. Personnel were trained in radiological safety, and standards governing maximum permissible exposures (MPE) were established. The MPE was set at 3.9 R for the series. Film badges were provided for all of the participating personnel. Persons likely to be exposed to radiation were often provided with additional badges for more complete recording of exposure. An extensive weather forecasting group was established in order to predict wind directions and areas of potential fallout. Personnel were evacuated from danger areas before each detonation, and reentry to radioactive areas was restricted to the personnel required to retrieve important data. TEST OPERATIONS AND EXPOSURES Tests were conducted at both Enewetak Atoll and Bikini Atoll some 190 nmi (352 km) to the east of Enewetak. The Marshall Islanders were evacuated from Bikini in 1946 and Enewetak in 1948. Enewetak served as a base of operations and the place where

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smaller-yield devices were tested, and Bikini was an advance camp where the larger-yield devices were tested. Most of the U.S. Navy and Marine Corps personnel were on ships operating around Bikini providing supply, evacuation capability, and other support to the tests there. Most of the Army and Air Force personnel were on Enewetak. All the Services had personnel assigned to laboratory organizations whose operations were conducted on both atolls as well as other locations in the Pacific area. The operations ran smoothly except for two incidents. The airdropped demonstration test, CHEROKEE, was considerably off target; and the edge of the cloud from the last event fired at Bikini, TEWA, passed over Enewetak causing fallout there. The missed airdrop caused no exposure of personnel to ionizing radiation as the entire Bikini Atoll had been evacuated, and the miss was in the direction of the open sea. But the TEWA fallout on the Enewetak base camp did lead to the exposure of the personnel there. The incident occurred toward the end of the series when some personnel had already returned to the United States, but the remaining Enewetak personnel received about an additional 1.5 R exposure from this incident. The overall average exposure for the series was approximately 1.7 R. The highest exposures were recorded by Air Force flight officers whose aircraft penetrated the nuclear clouds on scientific missions. The recorded REDWING exposures are summarized in the following table by service affiliation. Civilians employed by the Services have been included with the uniformed personnel. Other participants included personnel from other U.S. Government agencies including the AEC, AEC contractors, and foreign military and U.S. media observers.

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Summary of REDWING exposures No. of High Persons Not o.oo1- 1.000- 3.000- 5.000- Over Recorded * From 1945 to 1962 the United States conducted several series of underwater, * * in 1978 was assigned as Department of Defense’s (DoD) Executive Agent to * * conduct a program to identify DoD participants, determine radiation doses, * * and write histories of the series. This fact sheet summarizes information * * on OPERATION REDMING, one of those test series. Further information can be *