Date

Aug 4, 1961

Description

Before the AEC became interested in systematic study of the biological-environmental issues, one of the Defense Department's chief concerns in this matter was the problem of constraints; that is, ensuring that nuclear strikes did not produce levels of radioactive fallout that could endanger populations in nearby friendly countries. This became an important issue in the preparation of nuclear war plans - the SIOP, or Single Integrated Operational Plan. The JCS therefore instructed the Joint Strategic Target Planning Staff to follow a constraints policy by selecting weapons for striking specific "burst points" that would "minimize local fallout in the non-Soviet areas." Given Helsinki's very close location to the former Soviet Union, setting boundaries for fallout "doses" meant that "Helsinki became the control point which had the greatest effect upon the targeting process." Soviet bloc cities were not far: for example, Leningrad, with many military targets in and around it, was 242 miles away, and Tallinn 54 miles. Accordingly, for nearby targets, the JSTPS reassigned weapons, with smaller weapons replacing larger weapons and air bursts replacing surface bursts.

Following Johnson's request, the DASA compared the impact to Helsinki from using standard nuclear weapons striking nearby Soviet targets, following the latest constraints, to the impact of using clean and "immaculate" weapons. "Clean" weapons were designed to ensure that most of the explosive yield was caused by nuclear fusion instead of fission. "Immaculate" or "super-clean" weapons were all-fusion devices that proved elusive.

According to Booth, variable meteorological conditions made it impossible to assure that nuclear strikes would not endanger the Finns. Nevertheless, DASA estimated that the "total expected dose" at Helsinki would be 91r(ads) using standard weapons with constraints, 23r using clean weapons, and 6.5r using "immaculate" weapons. As radiation sickness was associated with exposure to 100 rads or higher, 91r was close to the threshold.

Source

Record Group 330, Records of the Department of Defense, Office of the Assistant to the Secretary of Defense (Atomic Energy), Accession 69-A-2243, "AW- Ecological Study, Volumes I and II"

Document published in following posting(s):

"Clean" Nukes and the Ecology of Nuclear War

Aug 30, 2017

Memorandum from Major General Robert Booth, Chief, Defense Atomic Support Agency, to Assistant to the Secretary of Defense (Atomic Energy), "Estimate of Helsinki Expected Dose Resulting from Clean Weapons in SIOP-62," 4 August 1961, Top Secret, excised copy