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We have reinvestigated the β decay of 120Ag to levels in 120Cd. Significant deviations in the decays of low-lying states from that expected from a U(5) nucleus have been observed. The results from this paper which include the 02+ and 31+ states (which have now been correctly identified) and previous work on lighter Cd isotopes strongly suggest that the anharmonic vibrator description of the even-even Cd isotopes is inadequate. Analysis of the decay patterns and half-life information led to the determination that there are three β-decaying isomers in 120Ag, with Jπ assignments of (0-, 1-), 4(+), and 7(-). In addition, we have identified four candidates of the quadrupole-octupole quintuplet. These states are Jπ = (5+) at 2489.5 keV, (4-) at 2208.4 keV, (2-) or (3-) at 2318.4 keV, and (1-) or (2-) at 2448.7 keV. All show strong transitions to the previously known 3- octupole state at 1898.9 keV. The overall level scheme of 120Cd has been significantly expanded. [ABSTRACT FROM AUTHOR]

We report the results of a β-decay study of fission products 86Br, 89Kr, 89Rb, 90gsRb, 90mRb, 90Kr, 92Rb, 139Xe, and 142Cs performed with the Modular Total Absorption Spectrometer (MTAS) and on-line mass-separated ion beams. These radioactivities were assessed by the Nuclear Energy Agency as having high priority for decay heat analysis during a nuclear fuel cycle. We observe a substantial increase in β feeding to high excited states in all daughter isotopes in comparison to earlier data. This increases the average γ-ray energy emitted by the decay of fission fragments during the first 10000 s after fission of 235U and 239Pu by approximately 2% and 1%, respectively, improving agreement between results of calculations and direct observations. New MTAS results reduce the reference reactor νe flux used to analyze reactor νe interaction with detector matter. The reduction determined by the ab initio method for the four nuclear fuel components, 235U, 238U, 239Pu, and 241Pu, amounts to 0.976, 0.986, 0.983, and 0.984, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Using archival peripheral blood slides from radiation accident patients, we have recently described the pseudo-Pelger Huët anomaly (PPHA) in neutrophils as a new radiation-induced biomarker, useful for dosimetry not only immediately after a radiation incident but also potentially helpful as a tool in retrospective dosimetry. In conjunction with the Radiation Accident Registry at the Radiation Emergency Assistance Center/Training Site (REAC/TS), the frequency of PPHA cells has been compared from selected patients in the Y-12 criticality accident in Oak Ridge, TN, in 1958 and from the patient in the 1971 60Co accident at the USAEC Comparative Animal Research Laboratory (CARL), also in Oak Ridge. Patients A, C, and D in the Y-12 accident are described as having an average dose of 2.53 ± 0.14 Gy gamma + 0.90 ± 0.05 Gy neutron, while the patient in the CARL event had 2.6 Gy gamma dose from event reconstruction. Since the average gamma energies are almost identical in these two cohorts, it is possible to estimate the deterministic neutron relative biological effectiveness (RBEd) for PPHA formation in a criticality event. The neutron RBEd calculated in this way is an average value over the neutron fission energy spectrum and is found to be 3.4 ± 0.6, in good agreement with the currently recommended value of 3 for acute neutron dose to red marrow., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Health Physics Society.)

The Radiation Emergency Assistance Center/Training Site (REAC/TS) is one of the US Department of Energy (DOE)/National Nuclear Security Administration (NNSA) Nuclear Emergency Response Team (NEST) assets and has been responding to radiological incidents since 1976. REAC/TS is in the Oak Ridge Institute for Science and Education (ORISE). A critical part of the REAC/TS mission is to provide emergency response, advice, and consultation on injuries and illnesses caused from ionizing radiation. Fortunately, radiation injuries are not frequent, but when they occur, they are more likely to be cutaneous radiation injuries (CRI) or internal contamination. In this paper, we will review selected cases from the REAC/TS experience in order to illustrate cutaneous patterns of injury and treatment options.

Americium is a man-made metal produced in very small quantities in nuclear reactors. Americium-241 is one of the radioactive isotopes of americium and has commercial applications, including use in smoke detectors. This is a case report of an occupational inhalation of americium-241, treated with both effective external decontamination and the use of diethylenetriamine pentaacetate to promote decorporation. This experience is significant because of the potential for americium or similar radionuclides to be used in "dirty" bombs or other radiological dispersion devices to cause large-scale radioactive contamination.

We report the results of a β-decay study of fission products ^{86}Br, ^{89}Kr, ^{89}Rb, ^{90gs}Rb, ^{90m}Rb, ^{90}Kr, ^{92}Rb, ^{139}Xe, and ^{142}Cs performed with the Modular Total Absorption Spectrometer (MTAS) and on-line mass-separated ion beams. These radioactivities were assessed by the Nuclear Energy Agency as having high priority for decay heat analysis during a nuclear fuel cycle. We observe a substantial increase in β feeding to high excited states in all daughter isotopes in comparison to earlier data. This increases the average γ-ray energy emitted by the decay of fission fragments during the first 10 000 s after fission of ^{235}U and ^{239}Pu by approximately 2% and 1%, respectively, improving agreement between results of calculations and direct observations. New MTAS results reduce the reference reactor ν[over ¯]_{e} flux used to analyze reactor ν[over ¯]_{e} interaction with detector matter. The reduction determined by the ab initio method for the four nuclear fuel components, ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu, amounts to 0.976, 0.986, 0.983, and 0.984, respectively.

It is crucial to integrate health physics into the medical management of radiation illness or injury. The key to early medical management is not necessarily radiation dose calculation and assignment, but radiation dose magnitude estimation. The magnitude of the dose can be used to predict potential biological consequences and the corresponding need for medical intervention. It is, therefore, imperative that physicians and health physicists have the necessary tools to help guide this decision making process. All internal radiation doses should be assigned using proper dosimetry techniques, but the formal internal dosimetry process often takes time that may delay treatment, thus reducing the efficacy of some medical countermeasures. Magnitudes of inhalation or ingestion intakes or intakes associated with contaminated wounds can be estimated by applying simple rules of thumb to sample results or direct measurements and comparing the outcome to known limits for a projection of dose magnitude. Although a United States regulatory unit, the annual limit on intake (ALI) is based on committed dose, and can therefore be used as a comparison point. For example, internal dose magnitudes associated with contaminated wounds can be estimated by comparing a direct wound measurement taken soon after the injury to the product of the ingestion ALI and the associated f1 value (the fractional uptake from the small intestine to the blood). International Commission on Radiation Protection Publication 96, as well as other resources, recommends treatment based on ALI determination. Often, treatment decisions have to be made with limited information. However, one can still perform dose magnitude estimations in order to help effectively guide the need for medical treatment by properly assessing the situation and appropriately applying basic rules of thumb.

The Biodosimetry Assessment Tool software application under development will equip health care providers with diagnostic information (clinical signs and symptoms, physical dosimetry, etc.) germane to the management of human radiation casualties. Designed primarily for prompt use after a radiation incident, the user-friendly program facilitates collection, integration, and archiving of data obtained from exposed persons. Data collected in templates are compared with established radiation dose responses obtained from the literature to provide multiparameter dose assessments. The program archives clinical information (e.g., extent of contamination, wounds, infection, etc.) useful for casualty management, displays relevant diagnostic information in a concise format, and can be used to manage both military and civilian radiation accidents. In addition, monitoring of diagnostic information of individuals using this program could potentially minimize the severity of psychological casualties by making a marked impact on the way that both radiation casualties and the worried well view their exposure, dose, and future risk for the development of disease.

Early estimation of dose is useful in the medical evaluation of severe radiation accidents. In a prior publication, lymphocyte depletion kinetics were shown to follow an exponential decline for gamma accidents in which the average whole-body dose was in the range 50 cGy < D < 8-10 Gy. In that study, the depletion rate constant was linearly related to dose, within the statistical variation of the historical hematological data. This simple technique has now been extended to include analysis of various types of criticality accidents (liquid process; water moderated systems; metallic systems). Lymphocyte depletion in high-level mixed gamma/neutron accidents is found to be approximately equal, at a given effective dose, to that for gamma accidents. This universality would indicate a neutron RBE for human lymphocytes close to unity. Furthermore, the technique appears to be insensitive to the shape of gamma and neutron spectra, therefore making it especially robust for initial, approximate dose estimation.

Early treatment of victims of high level acute whole-body x-ray or gamma exposure has been shown to improve their likelihood of survival. However, in such cases, both the magnitude of the exposure and the dosimetry profile(s) of the victim(s) are often not known in detail for days to weeks. A simple dose-prediction algorithm based on lymphocyte kinetics as documented in prior radiation accidents is presented here. This algorithm provides an estimate of dose within the first 8 h following an acute whole-body exposure. Early lymphocyte depletion kinetics after a severe radiation accident follow a single exponential, L(t) = L(o)e(-k(D¿t), where k(D) is a rate constant, dependent primarily on the average dose, D. Within the first 8 h post-accident, K(D) may be calculated utilizing serial lymphocyte counts. Data from the REAC/TS Radiation Accident Registry were used to develop a dose-prediction algorithm from 43 gamma exposure cases where both lymphocyte kinetics and dose reconstruction were felt to be reasonably reliable. The inverse relationship D(K) may be modeled by a simple two parameter curve of the form D = a/(1 + b/K) in the range 0 < or = D < or = 15 Gy, with fitting parameters (mean +/- SD): a = 13.6 +/- 1.7 Gy, and b = 1.0 +/- 0.20 d(-1). Dose estimated in this manner is intended to serve only as a first approximation to guide initial medical management.

It is well established that short-term clearance of an intravenous calcium load in vivo reflects bone uptake. Using results from isotope-dilution experiments with 42Ca, a 3-h test has been developed to measure a quantity, gamma, related to bone accretion. This test is proposed as a useful, clinically applicable measure of bone status. For early times, t, after a bolus of 42Ca, plasma tracer dilution was well approximated by t-gamma, where gamma is related to the fractional rate of loss of tracer, q, from blood into bone (1/q)(dq/dt) = -gamma/t). Gamma was evaluated from kinetic measurements on 91 normal female children, adolescents, and adult women in the age range 4-50 years. For t < or = 3 h, all clearance curves were well fit by a power function. Gamma was found to vary from 0.244 +/- 0.031 for adult premenopausal women (N = 22) to 0.392 +/- 0.056 for prepubertal children (N = 29). Using the Spearman rank-order correlation test, gamma was correlated with bone accretion measured from classic calcium kinetic studies with a correlation coefficient of 0.721, significant at p < 0.005. In those cases in which accretion and resorption remain tightly linked, gamma also provides information on the state of calcium loss from bone. Gamma was evaluated in 14 subjects with bone disease characterised by increased resorption (osteoporosis, Paget's disease) and in 27 subjects with decreased accretion (osteogenesis imperfecta, types I, III, IV; steroid-treated juvenile dermatomyositis). All subjects with Paget's disease and with osteoporosis showed increased gamma, consistent with high bone turnover. The osteoporotic patients furthermore exhibited gamma increasing monotonically by approximately 1% per year after age 55.(ABSTRACT TRUNCATED AT 250 WORDS)

We present a new generalized compartmental model for calcium kinetics as measured by tracer concentration in blood plasma. The parameter measuring incorporation of calcium in bone discriminates between different levels of physical development in female teenagers and between teenagers and adults.

Burns of all kinds represent a serious class of traumatic injury, affecting over two million people annually in the United States alone. Of this number, over 70000 are serious enough to require extended hospitalization. Currently, there is no sensitive, quantitative technique for measuring the depth of thermal damage in such injuries. An ultrasonic pulse-echo technique is described here whereby such information can be obtained within a few minutes postburn. Results from model porcine experiments are given to illustrate the usefullness of the method, and implication for the clinical care of human burn victims are discussed.