Beta Particles
Beta particles are lighter than alpha particles and permeate more deeply, penetrating skin and traveling several feet in air, but are stopped by a fraction of an inch of metal or plastic.
Gamma and Neutron Radiation
Gamma and neutron radiation is continuously emitted through warhead exterior cases and endangers personnel during maintenance, disassembly, internal limited-life component exchange, handing, modification, transport, and storage. Gamma rays “require a layer of dense material, such as lead, for shielding”. 4 They are a radiation hazard for the entire body” and “can cause ionizations that damage tissue and DNA”. 5
Neutrons are high-speed nuclear particles that have an exceptional ability to penetrate other materials. 6 Neutron radiation also causes other items to become radioactive, including hardware and other materials inside or near the nuclear weapon. The radiation weighting factor [Wr] of ionizing neutron radiation is 5-20 times greater than gamma and beta, depending on neutron energy.7 Shielding neutron radiation requires thick layers of materials rich in hydrogen, such as water or concrete.8
The emissions of the four types of nuclear radiation continue through a natural process of radioactive decay. The materials used in nuclear weapons generally range in half-life periods from 24,000 years to over 700 million years.9
Additional Information on Alpha Particles — Generally unknown to Cold War veteran Nuclear Weapons Technicians
"Plutonium predominantly emits alpha particles—a type of radiation that is easily stopped with a short range—and also neutrons, beta particles, and gamma rays. The alpha radiation makes it a serious internal hazard, made worse by its immobility in the body where it can remain for decades—as much as 80% of any amount absorbed will remain 50 years later. Just a few micrograms distributed through the lungs, liver, or bones can statistically increase the likelihood of cancer. This has contributed to its reputation as one of the most toxic substances known— the Department of Energy’s limit of occupational concentration in air is about a million times lower than for lead. Nonetheless, there are organic toxins that are many factors more deadly—plutonium absorption is mainly dangerous in the long term. Consequently, this aspect of plutonium can be managed with careful monitoring." 10
________________________________________
Footnotes:
[1] A VA claim/appeal response included incorrect comments stating unexploded nuclear weapons were not radiation risks because they were “sealed and shielded”. https://www.va.gov/vetapp20/Files7/20048516.txt
[2] https://www.cdc.gov/nceh/radiation/ionizing_radiation.html. Reviewed 7-16-23.
[3] Centers for Disease Control and Prevention (CDCP) (2015): European Nuclear Society, “Learning from Fukushima: Nuclear power in East Asia, 2017.” https://press-files.anu.edu.au/downloads/press/n3873/pdf/ch08.pdf.
[4] DOD Nuclear Matters Handbook 2020 (revised), Ch 11, p. 134.
[5] EPA.gov/radiation/radiation-basics. Reviewed 7-16-23.
[6] Nuclear Regulatory Commission. https://www.nrc.gov/about-nrc/radiation/health=effects/radiation-basics.html. Reviewed 10-27-23.
[7] Ibid. CDC (2015). Table 8-1, Radiation weighting factor. Note: https://www.nrc.gov/reading-rm/doc-collections/cfr/part020/part020-1004.html. Includes “Quality Factor” of 10 for “Neutrons of unknown energy”
[8] Ibid. DOD Nuclear Matters Handbook
[9] Nuclear Weapons Technology 101 for Policy Wonks, B. Goodwin, Lawrence Livermore National Lab, 2021.
[10] Los Alamos National Laboratory, “A History of Plutonium”, by Owen Summerscales, September 21, 2022. https://discover.lanl.gov/publications/actinide-research-quarterly/first-quarter-2022/shining-light-on-a-dark-element/. Retrieved 11-21-23.