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Iodine is needed to maintain health
Published in Tatsuo Kaiho, Iodine Made Simple, 2017
Typical radioactive iodine isotopes include iodine 123, iodine 125, and iodine 131 (see the table). There are 15 radioactive iodine drugs, constituting one-third of all radioactive drugs. Iodine 123 has a half-life (13.2 hours) and γ ray (159 keV) energy suitable for diagnostic imaging. Iodine 123 is used for 12 diagnostic radiopharmaceuticals including ioflupane [123I]. Iodine 125 has a long half-life of 59.4 days and emits weak γ ray energy (27.5 keV), and is suitable for radiation treatment. For example, an iodine 125 seed (125I encapsulated in a 5 mm long, 1 mm diameter titanium capsule) is sold commercially. It is embedded into the focus of a prostate cancer patient using a dedicated needle.
Chapter 6 Radioisotopes and Nuclear Medicine
Published in B H Brown, R H Smallwood, D C Barber, P V Lawford, D R Hose, Medical Physics and Biomedical Engineering, 2017
131I is the isotope of iodine that is often used for treating an overactive thyroid gland, but it is not the only radioisotope of iodine. 123I and 125I are other radioisotopes of this element. All the isotopes of iodine have 53 protons in the nucleus, but the number of neutrons can be 70, 72 or 78 to give the three isotopes, i.e. 123I, 125I and 131I.
Revisiting Mobile Paste Reactor Fuel
Published in Nuclear Technology, 2023
Fuel blocking by the accumulation of fission gases, according to APDA Report 146, would not be a problem because of the limited fuel residence time within the fuel element—at most a few hours—before it and its entrained fission gases are removed (Ref.[2], Sec. III.B.4). Calculations by the ORIGEN 2 computer program[16],gORIGEN 2 is a well-validated simulation of reactor operation. show that after 1387 days of operation of a reactor at 36.542 MW(thermal)/tonne with a neutron flux of n cm–2 s–1, out of each tonne (1000 kg) of heavy metal fuel, 52.18 kg would have fissioned, producing 59.83 mol of xenon and 6.474 mol of krypton, mostly from the decay of the very short-lived isotopes of iodine and bromine. Some isotopes of xenon and krypton also have very short half-lives.
Post-Neutron Mass Yield Distribution in the Thermal Neutron Induced Fission of 233U
Published in Nuclear Science and Engineering, 2023
H. Naik, S. P. Dange, R. J. Singh, W. Jang
For relatively long-lived fission products, electrodeposited targets of 233U (~100 µg) covered with 0.025-mm-thick aluminum foils were wrapped with additional aluminum foil of the same thickness. They were doubly sealed with alkathene bags, kept inside two different plastic bottles, and irradiated one at a time in the reactor APSARA for 18 to 30 min at a flux of 1.2 × 1012 n‧cm−2‧s−1. The irradiated aluminum catchers were used for either direct gamma-ray spectrometry or radiochemical separation18 of fission products like isotopes of iodine. The radiochemical separation of the iodine samples was done after 50 to 55 min from the end of irradiation. Then, 5-mL aliquots of standard separated solution in a counting vial were kept inside the vial holder and mounted on a Perspex holder stand. For the unseparated samples, the aluminum catcher containing the fission products was folded into a small size like a point source and mounted on different Perspex plates. The gamma-ray spectrometry of the mounted unseparated samples was carried out within 65 to 72 min from the end of irradiation by using an 80-cm3 HPGe detector connected to a PC-based 4096-channel analyzer. On the other hand, the gamma-ray counting for the separated samples of iodine isotopes was done within 22 to 25 min after the radiochemical separation by using a precalibrated 45-cm3 HPGe detector connected to a PC-based 4096-channel analyzer. The resolution of the above-mentioned two detector systems was 2.0 keV at the photopeak of the 1332.5-keV gamma line of 60Co.
Estimated Radiation Doses and Projected Cancer Risks for New Mexico Residents from Exposure to Radioactive Fallout from the Trinity Nuclear Test
Published in Nuclear Technology, 2021
Steven L. Simon, André Bouville, Harold L. Beck
The radionuclides created during the Trinity detonation, as in other nuclear tests, can be classified as refractory or volatile according to whether their melting point was higher or lower than 1500°C (Ref. 8). For example, isotopes of iodine and cesium are classified as volatile, while isotopes of zirconium are classified as refractory.2,13 The refractory nuclides are those that condensed from the vaporized nuclear debris at earlier times after detonation compared to more volatile nuclides. The relative composition of refractory to volatile (R/V) nuclides in Trinity fallout, as for other nuclear tests, varied with location downwind (i.e., distance and TOA), reflecting the fact that the refractory nuclides tended to be preferentially incorporated into the larger particles, while more volatile nuclides tended to be preferentially deposited onto the surface of the smaller particles. Since the larger, more massive particles deposited earlier due to gravitational settling, the earlier the TOA, the greater the proportion of large particles enriched in refractory nuclides deposited and the greater the proportion of total activity deposited that was refractory, i.e., R/V was higher at close-in distances and lower at more distant locations. This phenomenon, termed fractionation, reflects that the R/V ratio in the deposited fallout differed from its “unfractionated” value in the debris cloud; that is, from the relative R/V ratio produced by the fission of the fuel.