Radioactive materials working with

The objectives of the P-9 work were summarized in an early memorandum by Drs. Compton and Smyth. The first objective that was stated was to guarantee the success of the Plutonium Project by providing an alternate method for the manufacture of plutonimn in case the W plants were to develop unexpected difficulties. In the absence of this contingency, the work was to provide, for future use, more efficient methods for utihzing uranium, with a higher and more easily accessible production of radioactive materials and with the possible... 

Apply to all work activities with radioactive materials, including transport. The main provisions relevant to transport are those relating to driver training and the need, under some circumstances, to prepare contingency plans for emergencies and enforced stoppages. 

Anyone working with different types of radioactive material should know the conditions when various materials may be present. The following provides some additional guidance as to where radioactive materials may be present ... 

When specifically labelled compounds are required, direct chemical synthesis may be necessary. The standard techniques of preparative chemistry are used, suitably modified for small-scale work with radioactive materials. The starting material is tritium gas which can be obtained at greater than 98% isotopic abundance. Tritiated water can be made either by catalytic oxidation over palladium or by reduction of a metal oxide ... 

Chemical advances frequently are driven by technology. The discovery that atoms have inner structure was an outgrowth of the technology for working with radioactive materials. In Chapter 2 we describe a famous experiment in which the structure of atoms was studied by bombarding a thin gold foil with subatomic particles. A contemporary example is the use of lasers to study the details of chemical reactions. We introduce these ideas in Chapters 7 and 8. 

Approved requirements for the packaging, labelling and carriage of radioactive material by rails A guide to the Health and Safety (Consultation with Employees) Regulations 1996 A guide to the Work in Compressed Air Regulations 1996... 

The radioisotopes of einsteinium are highly unstable and radioactive. The small amount of the element and its compounds produced are not likely to be available in most laboratories. Thus, they do not pose any general hazard except in the case of scientists working with nuclear materials who must take precautions in handling exotic elements. 

On the basis of a commercial spectrometer (Leybold-Heraeus LHS-10) the system has been modified for work with highly radioactive materials (the scheme is shown in Fig. 11 of Chap.B) ... 

While he was investigating radioactive isotopes with Ernest Rutherford in 1913, George de Hevesy had an idea. Nuclear scientists were commonly forced to work with only tiny quantities of radioactive material, which would be very difficult to see using standard techniques of chemical analysis. But every single atom of a radioisotope advertised its presence when it decayed, since the radiation could be detected with a Geiger counter. So, if a... 

TU any of the less-understood phenomena leading to the observed fall-out distribution resulting from a nuclear explosion occur on a relatively short time scale (a few tens of seconds or less). These short term phenomena lead to an initial distribution of radioactive material referred to as the source term in a fallout study. Many predictive calculations are based on an assumed source term, which of necessity has been quite oversimplified. Two typical simplifications made for purposes of model development are (1) that the radiochemical composition of fallout is well defined and uniform (2) that the particles comprising the initial debris are uniform with respect to settling rate in the atmosphere. The latter assumption has received considerable attention elsewhere, notably in the work of Miller (2). However, the former assumption concerning the radiochemical uniformity of the debris has received far less systematic attention. 

In a technique known as medical imaging, tracers are used in medicine for the diagnosis of internal disorders. Small amounts of a radioactive material, such as sodium iodide, Nal, which contains the radioactive isotope iodine-131, are administered to a patient and traced through the body with a radiation detector. The result, shown in Figure 4.11, is an image that shows how the material is distributed in the body. This technique works because the path the tracer material takes is influenced only by its physical and chemical properties, not by its radioactivity. The tracer may be introduced alone or along with some other chemical, known as a carrier compound, that helps target the isotope to a particular type of tissue in the body. 

It is a common experience when working with radioactive materials that a sample under investigation contains two or more radioisotopes. Assume that you have a sample with just two radioisotopes, one with a half-life about 10 times that of the other. The amounts of the two in the sample are too small to separate chemically. 

In other words, 1 MBq of tritium contains about 3 ng of tritium. Thus, an important feature of radionuclides becomes apparent—we routinely work with extremely small quantities of material. Pure samples of radioisotopes are called carrier free. Unless a radionuclide is in a carrier-free state, it is mixed homogeneously with the stable nuclides of the same element. It is, therefore, desirable to have a simple expression to show the relative abundances of the radioisotope and the stable isotopes. This specification is readily accomplished by using the concept of specific activity, which refers to the amount of radioactivity per given mass or other similar units of the total sample. The SI unit of specific activity is Bq/kg. Specific activity can also be expressed in terms of the disintegration rate (Bq or dpm), or... 

WORKING WITH RADIOACTIVE MATERIALS Generally Accepted Practices... 

When we put in a hard day s work, we want to be assured that we aren t being exposed to any unnecessary risks. Let s face it, at the end of our shift we all want to return safely to our homes in good health. Those working with radioactive materials therefore need to follow a few simple guidelines to help protect themselves from potential dangers. First and foremost, we must have a healthy respect for radioactive materials and radiation. Note that respect is different than fear. This respect will ensure that we do not get careless or complacent in our day-to-day activities. Secondly, we must maintain our exposure to radioactive materials in accordance with the ALARA principle. That is, we must maintain our exposure as low as reasonably achievable. Thirdly, three words will help enforce the... 

ALARA principle time, distance, and shielding. We should minimize our time working with radioactive materials, maximize the distance between us and the source of radiation, and use proper shielding to minimize our exposure. Finally, we must make sure that we understand and follow all the facility procedures and regulations regarding the use of radioactive materials so that our safety and that of our patients are assured. 

Perform experiments with volatile materials or radioactive gases in a well-ventilated fume hood rated for that class of work. Good practice for safety purposes is to conduct most work with radioactive materials in a fume hood. 

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