[en] Only three nuclear weapons produced by the Manhattan Project (MP) were used during World War II: Trinity Test, New Mexico on 16 July 1945, Hiroshima, Japan, on 6 August 1945, and Nagasaki, Japan, on 9 August 1945. Several sources and authors, including EM and RL (1967), Stacey (1970), Sanger (1981), and Buckley (2000), have written that it is unlikely that any Canadian uranium was used in the atomic weapons that ended WW II. These sources offer no detailed justification for their conclusion, nevertheless, after analysis of data contained in numerous sources, this article reaches a similar conclusion. (author)

[en] A method for producing synthetic debris similar to the melt glass produced by nuclear surface testing is demonstrated. Melt glass from the first nuclear weapon test (commonly referred to as trinitite) is used as the benchmark for this study. These surrogates can be used to simulate a variety of scenarios and will serve as a tool for developing and validating forensic analysis methods. (author)

No abstract available

[en] Pu-240, the first nuclide to be discovered by virtue of its spontaneous fission, was identified in 1944 at Los Alamos, with profound consequences for the Manhattan Project. (O. Chamberlain, G.W. Earwell, and E. Segre, Los Alamos Manuscript LAMS-131 (1946); Phys. Rev.94, 156 (1954). G. W. Farwell, Los Alamos Report LA-490 (1946); Ph.D. Thesis, University of Chicago (1948) (withheld from publication for reasons of national security.)) Two friends and colleagues from earlier days in Rome, Emilio Segre and Enrico Fermi, were largely responsible for this discovery. Segre's small group at Berkeley begin spontaneous fission studies of U and Pu in 1942 and extended and intensified these at Los Alamos beginning in June, 1943. By July, 1944, it was clear that Pu-240 was responsible for the high rates observed in these reirradiated samples. Massive reorientation from gun assembly to implosion assembly for the Pu weapon ensued, with a spectacular outcome witnessed on July 16, 1945, at the Trinity test site. Some details of this chain of events, and of the spontaneous fission experiments, will be presented

[en] This report describes the Weather Service Nuclear Support Office (WSNSO) analyses of the radiological and meteorological data collected for the TRINITY nuclear test. Inconsistencies in the radiological data and their resolution are discussed. The methods of normalizing the radiological data to a standard time and estimating fallout-arrival times are presented. The meteorological situations on event day and the following day are described. Comparisons of the WSNSO fallout analyses with analyses performed in the 1940s are presented. The radiological data used to derive the WSNSO 1987 fallout patterns are tabulated in appendices

[en] Fission reactions result in Nd isotope decay products which alter Nd isotopic compositions measured in nuclear debris. Trinitite samples measured by MC-ICP-MS show perturbations of Nd isotopes relative to ¹⁴²Nd, the only isotope of Nd which is blocked from fission product decay. By measuring ¹⁴⁴Nd/¹⁴²Nd and the total number of atoms of ¹⁴²Nd in the sample, it is possible to quantify the total number of fissions in nuclear debris, an important signature in post-detonation nuclear forensics. (author)

[en] A preliminary analysis of available data from Los Alamos Scientific Laboratory ground zero (GZ) study area at Trinity Site is discussed in an effort to develop a wind-driven plutonium transport model. The analysis reveals a dominant effect of precipitation in explaining variation in the data, although its product with normalized solar radiation pattern gives a much lower sum of squared residuals (SSR) from the regression line. The square of the average diurnal windspeed at the site was also observed to reduce the SSR further, but not to the extent expected relative to other factors. Failure to find significant plutonium concentration differences in collected dust (as a function of time and sampling height of Bagnold sampler collectors) made possible the formulation of a prediction equation for plutonium flux at GZ, using the product of the predicted dust flux at the site with the mean plutonium concentration for the dust samples analyzed

[en] The Trinity atmospheric explosion was performed with the 20 kilotons nuclear bomb Gadget detonated at a height of 30 m near the Socorro city in New-Mexico. This article presents the application of the NUKEMAP on-line simulation tool to the Trinity explosion. NUKEMAP gives the various circular zones where different effects are expected: the radius for a moderate over-pressure of 35 kPa is 1.27 km, the radius for a radiation dose of 5 Gray is 1.41 km, the radius for third-degree burns is 2.27 km and the radius for light over-pressure is 3.27 km. The radioactive fallout can also be simulated. (A.C.)

[en] This report presents data on calculated gamma radiation exposure rates and ground deposition of related radionuclides resulting from the Trinity Event

[en] Analysis of post-nuclear detonation materials provides information on the type of device and its origin. Compositional analysis of trinitite glass, fused silicate material produced from the above ground plasma during the detonation of the Trinity nuclear bomb, reveals gross scale chemical and isotopic heterogeneities indicative of limited convective re-homogenization during accumulation into a melt pool at ground zero. Regions rich in weapons grade Pu have also been identified on the surface of the trinitite sample. The absolute and relative abundances of the lanthanoids in the glass are comparable to that of average upper crust composition, whereas the isotopic abundances of key lanthanoids are distinctly non-normal. The trinitite glass has a non-normal Nd isotope composition, with deviations of -1.75 ± 0.60 ε (differences in parts in 10⁴) in ¹⁴²Nd/¹⁴⁴Nd, +2.24 ± 0.75 ε in ¹⁴⁵Nd/¹⁴⁴Nd, and +1.01 ± 0.38 ε in ¹⁴⁸Nd/¹⁴⁴Nd (all errors cited at 2σ) relative to reference materials: BHVO-2 and Nd-Ames metal. Greater isotopic deviations are found in Gd, with enrichments of +4 ± 1 ε in ¹⁵⁵Gd/¹⁶⁰Gd, +4.19 ± 0.75 ε in ¹⁵⁶Gd/¹⁶⁰Gd, and +3.48 ± 0.52 ε in ¹⁵⁸Gd/¹⁶⁰Gd compared to BHVO-2. The isotopic deviations are consistent with a ²³⁹Pu based fission device with additional ²³⁵U fission contribution and a thermal neutron fluence between 1.4 and 0.97 × 10¹⁵ neutrons/cm². (author)