Reduction of Radioactivity Emitted from Radioactive Material

Abstract

A method of reducing radiation emitted from a radioactive source material involves mixing the radioactive material with mica. Uranium ore is a radioactive source material which when mixed with mica significantly reduces the amount of radiation emitted. The radioactive source material and the mica may be ground to similar sized small pieces and mixed at a one to one ratio. The radioactive source material and the mica may be consistently mixed together. In the alternative the mica may be placed around the outside of the radioactive source material. The mica may contain manganese.

Claims

1. A method of reducing radiation emitted from a radioactive source material comprising: mixing mica with said radioactive source material.

2. The method of claim 1 wherein said radioactive source material is ground to small granules.

3. The method of claim 1 wherein said radioactive source material is ground to dust size particles.

4. The method of claim 1 wherein said radioactive source material is ground to 200 mesh.

5. The method of claim 4 further comprising the step of grinding the mica down to 200 mesh.

6. The method of claim 3 further comprising the step of grinding the mica down to dust size particles.

7. The method of claim 6 further comprising mixing said radioactive source material and said mica in a ratio of one to one.

8. The method of claim 5 further comprising mixing said radioactive source material and said mica in a ratio of one to one.

9. The method of claim 7 wherein said mica is a dark mica.

10. The method of claim 8 wherein said mica is a dark mica.

11. The method of claim 7 wherein said mica contains at least 800 ppm of manganese.

12. The method of claim 8 wherein said mica contains at least 800 ppm of manganese.

13. The method of claim 11 wherein said mica contains at least 3 percent of aluminum.

14. The method of claim 12 wherein said mica contains at least 3 percent of iron.

15. The method of claim 11 wherein said mica contains at least 700 ppm of phosphorus.

16. The method of claim 12 wherein said mica contains at least 1 percent potassium.

17. The method of claim 15 further comprising surrounding said radioactive source material with said mica.

18. The method of claim 16 further comprising surrounding said radioactive source material with said mica.

19. The method of claim 17 wherein said radioactive source material comprises uranium.

20. The method of claim 18 wherein said radioactive source material comprises uranium.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0016] In a FIGURE which illustrates aspects of non-limiting embodiments of the invention, FIG. 1 is a graph showing radioactivity readings plotted against time for Examples 1-4.

DESCRIPTION

[0017] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

[0018] It occurred to the inventor that mica could be used as a way to reduce the radioactivity in a given sample of uranium. The inventor surmised that if it is shown to work for a test sample then it would also have much broader application.

[0019] Mica is a type of crystal that occurs naturally in igneous, metamorphic and sedimentary rock. Mica is used to describe sheet silicate (phyllosilicate) minerals which have the general chemical formula:

X.sub.2Y.sub.4-6Z.sub.8O.sub.2O(OH,F).sub.4

in which

[0020] X is K, Na, or Ca or sometimes Ba, Rb, or Cs;

[0021] Y is Al, Mg, or Fe or sometimes Mn, Cr, Ti, Li, etc.;

[0022] Z is usually Si or Al, but also may include Fe3+ or Ti.

[0023] Muscovite is a phyllosilicate mineral of aluminum and potassium with formula:

KAl.sub.2(AlSi.sub.3O.sub.10)(F,OH).sub.2 or (KF).sub.2(Al.sub.2O.sub.3).sub.3(SiO2).sub.6(H.sub.2O).

[0024] For the purposes of testing, a reference grade radioactive sample of Pitchblende BL-5/U-238 (hereinafter BL-5) was purchased from Energy Mines and Resources in Ottawa, Ontario, Canada. Experimental tests with BL-5 and mica were conducted to confirm the invention.

[0025] BL-5 is a low-grade concentrate from Beaverlodge, Saskatchewan, Canada. BL-5 is in secular equilibrium.

TABLE-US-00001 TABLE 1 Certificate of Analysis for BL-5 Consensus Value 95% Confidence Interval U 7.09% 0.03% Ra-226 857 Bq/g 38 Bq/g Pb-210 866 Bq/g 21 Bq/g

[0026] The preparation and certification procedures used for BL-5 are set out in CANMET Reports 79-4 Uranium Ore BL-5a Certified Reference Ore which is available from CCRMP, CANMET in Ottawa, Ontario, Canada.

[0027] The present invention will be further clarified by the following specific examples, which are intended to be purely exemplary of the present invention, and the scope of the invention is not limited to the examples.

Example 1: 9.9 g of BL-5 with 9.9 g of Mica #1

[0028] In a laboratory, 9.9 g of BL-5 was mixed with 9.9 g of a first type of mica (mica #1), which is a muscovitic-type mica schist, and the radiation emitted from the combined sample was measured, using a Geiger Counter, over time.

TABLE-US-00002 TABLE 2 Measured Radioactivity of Example 1 Days Radioactivity (Sv/hr) 0 3.500 163 2.000 380 1.800 541 1.000 596 0.600 646 0.058 661 0.032 693 0.020

Example 2: 10.1 g of BL-5 with 10.1 g of Mica #2

[0029] In a laboratory, 10.1 g of BL-5 was mixed with 10.1 g of a second type of mica (mica #2), which is a dark mica, and the radiation emitted from the combined sample was measured, using a Geiger Counter, over time.

TABLE-US-00003 TABLE 3 Measured Radioactivity of Example 2 Days Radioactivity (Sv/hr) 0 3.900 161 2.800 216 1.000 266 0.271 282 0.035

Example 3: 70.0 g of BL-5 with 70.0 g of Mica #2

[0030] In a laboratory, 70.0 g of BL-5 was mixed with 70.0 g of the second type of mica and the radiation emitted from the combined sample was measured over time.

TABLE-US-00004 TABLE 4 Measured Radioactivity of Example 3 Days Radioactivity (Sv/hr) 0 3.800 61 3.000 90 2.500 121 1.030 152 0.100 215 0.200 246 0.075

[0031] For examples 1-3, the BL-5 and the mica were combined at approximately the same size particles, with the mica ground to 200 mesh.

Example 4: 50.0 g of BL-5 without Mica

[0032] BL-5 is a reference material which contains radioactive material, primarily uranium, which is not expected to appreciably decrease in radioactivity for thousands of years. A control experiment was not yet performed however it is expected that the radioactivity of a control sample of BL-5 would not change measurably over a period of years.

TABLE-US-00005 TABLE 5 Expected Radioactivity of Example 4 Days Radioactivity (Sv/hr) 0 5.0 75 5.0 150 5.0 225 5.0 300 5.0 375 5.0 450 5.0 700 5.0

[0033] The base reading of radioactivity for the BL-5 immediately prior to mixing with mica in examples 1-3 was measured as 5.0 Sv/hr.

[0034] FIG. 1 is a graph 100 plotting Radioactivity (Sv/hr) over Time (Days) for the above example 1 as plotted with line 110, example 2 which is plotted as line 120, example 3 plotted as line 130 and example 4 plotted as line 140. As can be seen for examples 1-3, the initial mixing of mica with the BL-5 resulted in an immediate drop (from 5 Sv/hr) for measured radiation emitted, and then the radiation emitted continued to drop off over time until it reached background radiation levels. In examples 2 and 3 wherein mica #2 was used, the completed drop off in radiation emitted took less than one year, whereas for example 1 using mica #1 it took less than two years.

[0035] The mica #1 was chemically analyzed for constituents and was found to have the following elements in decreasing order measured by percentage.

TABLE-US-00006 TABLE 6 Analysis of Mica #1 Element Percentage Mg 5.12% Al 3.93% Fe 3.88% K 2.82% Ca 0.57% P 0.37% Na 0.11% Ti 0.10% S <0.01%

[0036] The mica #1 was chemically analyzed for additional constituents and was found to have the following elements in decreasing order measured in parts per million (ppm).

TABLE-US-00007 TABLE 7 Analysis of Mica #1 Element PPM Cr 895 Mn 871 Ni 336 Zn 316 Be 229 Ba 82 Co 38 V 38 Ga 29 Pb 22 Sr 19 Sb 14 B 10

[0037] The mica #2 was chemically analyzed for constituents and was found to have the following elements in decreasing order measured by percentage.

TABLE-US-00008 TABLE 8 Analysis of Mica #2 Element Percentage Al 7.94% Fe 5.49% Mg 1.52% K 1.42% Ca 1.17% Na 1.09% Ti 0.42% S 0.01%

[0038] The mica #2 was chemically analyzed for additional constituents and was found to have the following elements in decreasing order measured in parts per million (ppm).

TABLE-US-00009 TABLE 9 Analysis of Mica #2 Element PPM Mn 1335 P 790 Ba 580 Sr 178 V 163 Zn 121 Cr 100 Ni 33 Sc 25 Cu 22 Ga 20 La 20 Co 12 Pb 11

[0039] Further experimentation is required to better understand the metes and bounds and full applications of this invention.

[0040] For example, experimentation can be conducted in which mica is used as a border substance with the uranium ore or other radioactive sample in the middle, to see if the mica has the same effective if it is used merely as a shield on the outside as opposed to being mixed together with the radioactive sample.

[0041] Another experiment could be to vary the sizes of the granules of the mica. Another experiment would be to vary the granule sizes of the uranium and or the radioactive sample.

[0042] Other experimental variations include varying the quantity of mica with respect to the uranium ore or other radioactive sample. It has been tested at a one-to-one ratio of mica to BL-5, however different ratios may also be effective and further experimentation may lead to a better understanding and/or optimization of the ratios that are effective.

[0043] Preferably all experiments would be completed contemporaneously with a uranium ore sample tested without a mica or other placebo added. Experimental runs can be completed with one or more placebo mica substitutes.

[0044] In addition, further experimentation may be performed using the existing samples to attempt to separate the BL-5 and/or the radioactive elements from the mica to see if it is separable, for example by centrifuge or other laboratory means. If separable the radioactivity of the mica and BL-5 can be further measured.

[0045] Further experimentation can test different types of mica and ascertain the effectiveness of various different forms of mica. The mica used in the experiments can be tested to assess whether there are other elements and/or components within the mica samples that may contribute to the effects observed.

[0046] The core invention is the reduction of radiation emitted from a radioactive sample by combining with mica, and these further experiments may further refine and improve the understanding of the invention without materially altering the invention.

[0047] It is intended that the present specification and examples be considered as exemplary only with a true scope and spirit of the invention being indicated by the following claims and equivalents thereof.

[0048] Further, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range.

[0049] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein. Rather the scope of the present invention includes both combinations and sub-combinations of the features described herein as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art. Furthermore, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.