How old is it?—241Pu/241Am nuclear forensic chronology reference materials

Abstract

One material attribute for nuclear forensics is material age. 241Pu is almost always present in uranium- and plutonium-based nuclear weapons, which pose the greatest threat to our security. The in-growth of 241Am due to the decay of 241Pu provides an excellent chronometer of the material. A well-characterized 241Pu/241Am standard is needed to validate measurement capability, as a basis for between-laboratory comparability, and as material for verifying laboratory performance. This effort verifies the certification of a 38 year old 241Pu Standard Reference Material (SRM4340) through alpha-gamma anticoincidence counting, and also establishes the separation date to two weeks of the documented date.

Simultaneous Isotopic Analysis of U, Pu, and Am in Spent Nuclear Fuel by Resonance Ionization Mass Spectrometry

“…For example, the measured Pu isotopic compositions of spent fuel of unknown origin can be compared to computational models of known reactors to attribute source terms. − The isotopic composition of Pu is important from a nonproliferation standpoint because weapons-grade material requires a certain level of enrichment of the fissile isotope 239 Pu . The ingrowth of daughter 241 Am from parent 241 Pu can be used to determine the elapsed time since irradiation in a reactor . Plutonium isotopic composition is used to characterize the source terms of environmental Pu, for example, for distinguishing the material from the Fukushima incident from global fallout. , …”

“…4 The ingrowth of daughter 241 Am from parent 241 Pu can be used to determine the elapsed time since irradiation in a reactor. 5 Plutonium isotopic composition is used to characterize the source terms of environmental Pu, for example, for distinguishing the material from the Fukushima incident from global fallout. 6,7 In nonproliferation and reactor characterization, in particular, the ability to analyze small samples can be important.…”

Recent Advances in Nuclear Forensic Chemistry

“…Accurate chronometry requires effective chemical separations and highly sensitive detection techniques, with the former achieved using inorganic chemistry and the latter typically accomplished using MS. , Since multiple chronometers are generally measured for a given sample, intentional age spoofing by isotopic dilution would be extremely difficult and even counterproductive, as mismatched chronometers can provide a fingerprint for intentional obfuscation of the data . The applications of chronometry in nuclear forensic analysis have been covered in significant detail elsewhere, ,,,, and an in-depth review of these processes would be redundant in light of these previous articles. However, chronometric studies using data obtained from MS are a critical part of the source attribution process in nuclear forensics, , comprising one of the primary applications for isotopic data.…”

“…Another serious but less catastrophic concern related to nuclear terrorism is the detonation of a radiological dispersal device (RDD), commonly known as a "dirty bomb". This is a device that uses conventional explosives to disperse a highly radioactive but nonfissile source, such as 60 Co, 137 Cs, 90 Sr, 99 Mo, 241 Am, etc., with the goal of spreading radioactive contamination in a populated area. The detonation of an RDD in an urban area could lead to mass panic and a high economic cost of cleanup and evacuation, causing these devices to be termed "weapons of mass disruption".…”