Method for preparing radioactive 125I and intermittent circulation loop device

Abstract

The present invention belongs to the field of preparation of radioactive nuclide. It discloses a kind of preparation method of radioactive iodine and the intermittent closed circuit apparatus that used in this method. The characteristic of this method is irradiated the Xe gas in the irradiation bottle that placed in the reactor active area and transferred it out of the reactor to disintegrate, separate, recycle, purify, split charging, etc. At the same time, the circulating irradiated Xe gas would be inflated to the irradiation bottle of reactor active area, and the process of irradiation and disintegration would be carried on. The characteristic of this apparatus is that except irradiation bottle is in the active area of reactor, all the other equipments are placed out of the noumenon of reactor and connected to the irradiation bottle through main pipe. And there are 2 to 7 used disintegration bottle. The needle-shape tube with the cooling trap is connected to the main pipe between the irradiation bottle and aspirator. íí

Description

technical field [0001] The invention belongs to the field of radionuclide preparation, and in particular relates to a method for preparing radioactive iodine and an intermittent circulation loop device used in the method. Background technique [0002] 125 I is a radioactive isotope of iodine with a long half-life (T 1 / 2 = 59.7 days), which releases low-energy gamma rays (27KeV X-rays) by electron capture. because 125 I has a long half-life, low gamma ray energy, and no beta - Radiation, the radiation dose caused to the human body is low, so it is widely used in clinical diagnosis of nuclear medicine, biomedical research and tumor brachytherapy (X-ray seed source). In 1951, I. Bergstro reported the production of natural xenon under reactor thermal neutron irradiation 125 I method. Henceforth, using reactors to mass-produce 125 I's methods are constantly being developed. Its nuclear reaction is: [0003] <chemistry num="001"> <chem file="200410037654_cml001...

AI Technical Summary

Problems solved by technology

The main disadvantages of the batch method are: 125 Xe and 125 Thermal neutron reaction cross section ratio of I 124 Xe is much larger, under long-time irradiation, the secondary nuclear reaction makes 125 I's output dropped a lot and caused losses

But, there are two problems in this method and device, one is 125 The Xe decay bottle, liquid nitrogen trap and some control valves are all submerged in the water tank on the upper part of the reactor. The requirements for the reactor are relatively strict, and the auxiliary facilities of the reactor are added, which cannot be realized on a general reactor.

At the same time, the reactor top cover needs to be continuously opened during each batch of production, which has a certain impact on the normal operation of the reactor.

The second is that the circuit has only one decay bottle, 125 When Xe stays in the decay bottle, the irradiation bottle is empty, which wastes the neutron resources of the reactor. In order to make full use of the neutron resources of the reactor, it is necessary to minimize 125 The decay time of Xe in the decay bottle, resulting in a part of 125 Xe did not decay into 125 I

Images