ESTIMATES AND EVALUATION OF FALLOUT IN THE UNITED STATES FROM NUCLEAR WEAPONS TESTING CONDUCTED THROUGH 1962

Technical Report · Wed May 01 00:00:00 EDT 1963

OSTI ID:4697084

The Federal Radiation Council made a full study and analysis of fallout expected in the current year from nuclear tests in the past. In this case the report covers fallout expected in the next few years from Soviet and United States tests conducted to date. Although absolute fallout levels in the U. S. in 1963 will probably be substantially increased over 1962 if rainfall is normal, they will still be, in relative terms, far short of figures which would cause concern or justify counter-measures. Cumulative whole-body radiation doses from all past tests is estimated to be 110 millirems in 30 years, which is about one- thirtieth the exposure from natural sources such as soil, rocks, and building materials. The special cases of iodine-131 and strontium-90, the two radionuclides of most concern to the public, have been thoroughly reviewed and specifically included in the general conclusion. The Council concludes that the health risks from radioactivity in foods, now and over the next several years, are too small to justify countermeasures to limit intake of radionuclides by diet modifications or altering the normal distribution and use of food, particularly milk and dairy products. The substantial increase in absolute amounts of fallout is due primarily to Soviet nuclear tests. The amount of fission yield in the thermonuclear test explosions is a measure of the quantity of strontium-90 and other fission products produced by the tests. The total yield of thermonuclear explosions is a measure of the carbon-14 produced. Since the Soviet Union ended the threeyear moratorium by resuming nuclear tests in 1961, Soviet testing has produced 85 megatons of flssion yield, and U. S. testing 16 megatons. This report updates weapons testing information to include all tests conducted through 1962. The USSR conducted atmospheric tests at levels of 120 megatons (MT) total yield and 25 MT fission yield in 1961; 180 MT total yield and 80 MT fission yield in 1982. A few of the underground tests conducted by the U. S. in 1961 resulted in some venting to the atmosphere. The U. S. conducted a series of atmospheric tests in the Pacific at a level of 37 MT total yield and 16 MT fission yield in 1962 plus a few low yield tests at the Nevada Test Site. Measurements of strontium-90 in food supplies and the total diet in the U. S. show that the levels rose from a value of 4 to 8 strontium units (SU) in 1961 to 8-13 SU in 1962, and may rise to a peak value of 50 SU in 1963. The predicted concentrations of strontium-90 in milk for 1983 are twice the values observed in 1962 and about 4 times the values observed in 1961. The strontium-90 concentrations in human bone are expected to rise from an observed value of 2.6 SU in 1961 to 7 SU in 1964. The presently estimated radiation dose to bone from all past tests is about 465 millirems in 70 years, which is about one-twentieth the exposure from natural sources. It should be noted that these presently predicted values are no greater than those which were predicted in the FRC Report No. 3 as likely to result from all tests conducted prior to 1962. This is because the measured levels are lower than originally predicted. It was estimated in 1962 that carbon-14 resulting from tests conducted through 1981 would give an average per capita radiation dose to the whole-body including the reproductive cells of 10 to 15 millirems in the flrst 30 years. It is now estimated that the carbon-14 produced by testing conducted in 1962 will produce a comparable radiation dose in the first 30 years. When the carbon-14 now in the atmosphere has equilibrated with the oceans, the natural levels will be increased by about 4 percent instead of the 2 percent previously reported. (auth)

• Research Organization: Federal Radiation Council, Washington, D.C.
• NSA Number: NSA-17-025480
• OSTI ID: 4697084
• Report Number(s): NP-12879(Rpt.4)
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

HEALTH AND SAFETY
ABSORPTION
ADSORPTION
ATMOSPHERE
BACKGROUND
BODY
BONES
BUILDING MATERIALS
CARBON
CARBON 14
COUNTERS
DIET
FALLOUT
FISSION PRODUCTS
FOOD
IODINE 131
MAN
MEASURED VALUES
MILK
NUCLEAR EXPLOSIONS
QUANTITATIVE ANALYSIS
RADIATION DOSES
RADIATION EFFECTS
RADIOACTIVITY
RAIN
ROCKS
SAMPLING
SEA
SOILS
STANDARDS
STRONTIUM 90
UNDERGROUND EXPLOSIONS