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The Frisch-Peierls memorandum: A seminal document of nuclear history
The Manhattan Project is usually considered to have been initiated with Albert Einstein’s letter to President Franklin Roosevelt in October 1939. However, a lesser-known document that was just as impactful on wartime nuclear history was the so-called Frisch-Peierls memorandum. Prepared by two refugee physicists at the University of Birmingham in Britain in early 1940, this manuscript was the first technical description of nuclear weapons and their military, strategic, and ethical implications to reach high-level government officials on either side of the Atlantic. The memorandum triggered the initiation of the British wartime nuclear program, which later merged with the Manhattan Engineer District.
Javiera Cervini-Silva
Nuclear Technology | Volume 210 | Number 8 | August 2024 | Pages 1487-1495
Note | doi.org/10.1080/00295450.2023.2295152
Articles are hosted by Taylor and Francis Online.
Bentonites are natural reservoirs of various elements and are of interest because they are sources of thorium and uranium, which are transition elements that provide nuclear energy. The objective of this work was to study the plausible association(s) of these elements with other transition elements of interest. The contents of 18 transition elements (cerium, cobalt, chromium, copper, iron, hafnium, lanthanum, manganese, molybdenum, neodymium niobium, nickel, tantalum, thorium, uranium, vanadium, yttrium, zinc, and zirconium) in 38 bentonites determined experimentally by X-ray fluorescence spectroscopy (XRF) were analyzed.
The contents of the elements were plotted in (x,y) graphs and then fitted to polynomial functions (orders 1 through 6). According to the coefficient of determination (r2: 0.5 ≤ r2 strong, 0.3 ≤ r2 ≤ 0.5 medium, and r2 ≤ 0.3 weak), the contents of thorium, uranium, niobium, and nickel related strongly, thus the presence of niobium and nickel served to predict the presence of detectable concentrations of thorium and uranium. The equations showing higher r2 values were
1. {Th} = 1e-6{Nb}5 − 3e-4{Nb}4 + 1.9e-2{Nb}3 − 5.4e-1{Nb}2 + 7.3{Nb} − 6.3, r2 = 0.53.
2. {Th} = −3e-8{Nb}6 + 9e-6{Nb}5 − 1e-3{Nb}4 + 4.7e-2{Nb}3 − 1.1{Nb}2 + 11.5{Nb} − 16, r2 = 0.54.
3. {Th} = 5e-6{Ni}4 − 1.5e-3{Ni}3 − 1.5e-1{Ni}2 − 5.8{Ni} + 9e+1, r2 = 0.49.
4. {Th} = −7e-8{Ni}5 + 3e-5{Ni}4 − 5.1e-3{Ni}3 + 3.4e-1{Ni}2 − 9.5{Nb} + 1e+2, r2 = 0.56.
5. {Th} = 2e-9{Ni}6 − 8e-7{Ni}5 + 2e-4{Ni}4 − 1.5e-2{Ni}3 − 7e-1{Ni}2 − 1e+1{Ni} + 1e+1, r2 = 0.60.
6. {Th} = −1e-4{U}5 + 1.3e-2{U}4 − 4.3e-1{U}3 + 5.7e-1{U}2 − 2e+1{U} + 5e+1, r2 = 0.54.
7. {Th} = 6e-6{U}6 − 9e-4{U}5 + 4.5e-2{U}4 − 1.1{U}3 + 1e+1{U}2 − 5e+1{U} + 1e+2, r2 = 0.64.
8. {U} = 8e-6{Nb}4 − 1.2e-3{Nb}3 + 4.8e-2{Nb}2 − 4.3e-1{Nb} + 6.8, r2 = 0.48.
9. {U} = 2e-7{Nb}5 − 4e-5{Nb}4 + 2.8e-3{Nb}3 − 7.6e-2{Nb}2 + 1.1{Nb} + 1.9, r2 = 0.5.
10. {U} = 1e-8{Nb}6 − 3e-6{Nb}5 + 2e-4{Nb}4 − 8e-3{Nb}3 + 1.3e-1{Nb}2 − 5.4e-1{Nb} + 5.4, r2 = 0.51.
11. {U} = 1.8e-1{Th} + 2.6, r2 = 0.49; {U} = 1.7e-3{Th}2 − 2.9e-2{Th} + 6.3, r2 = 0.60.
12. {U} = 2e-5{Th}3 − 1.7e-3{Th}2 + 1.4e-1{Th} + 4.5, r2 = 0.58; {U} = −5e-7{Th}4 + 2e-4{Th}3 − 1.5e-2{Th}2 + 5.5e-1{Th} + 1.5, r2 = 0.6.
13. {U} = −7e-9{Th}5 + 2e-6{Th}4 − 1e-4{Th}3 − 3e-4{Th}2 + 2.7e-1{Th} + 2.9, r2 = 0.6.
14. {U} = 2e-9{Th}6 − 8e-7{Th}5 + 1e-4{Th}4 − 8.1e-3{Th}3 − 2.4e-1{Th}2 + 15, r2 = 0.65.
This study provided a joint experimental and theoretical approach to optimize the recovery of thorium and uranium and to save invaluable onsite and off-site natural resources and work time. The findings might expand on other studies reporting the quantification of transition metals on bentonite matrices. For instance, the concentrations of nickel reported in studies using bench techniques could serve as the basis to calculate the contents of thorium.
