CN108919334A - A kind of UF6The verification measurement method of uranium quality and abundance in big tank - Google Patents
A kind of UF6The verification measurement method of uranium quality and abundance in big tank Download PDFInfo
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- CN108919334A CN108919334A CN201810959927.6A CN201810959927A CN108919334A CN 108919334 A CN108919334 A CN 108919334A CN 201810959927 A CN201810959927 A CN 201810959927A CN 108919334 A CN108919334 A CN 108919334A
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- neutron intensity
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- abundance
- uranium
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- 229910052770 Uranium Inorganic materials 0.000 title claims abstract description 53
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 238000012795 verification Methods 0.000 title claims abstract description 15
- 238000000691 measurement method Methods 0.000 title claims abstract description 11
- 238000001514 detection method Methods 0.000 claims abstract description 6
- 238000012417 linear regression Methods 0.000 claims description 8
- 238000000108 ultra-filtration Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 abstract description 15
- 238000005516 engineering process Methods 0.000 abstract description 4
- 239000000941 radioactive substance Substances 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 19
- 239000011824 nuclear material Substances 0.000 description 13
- 239000000463 material Substances 0.000 description 6
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003758 nuclear fuel Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000005251 gamma ray Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000002901 radioactive waste Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T3/00—Measuring neutron radiation
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- High Energy & Nuclear Physics (AREA)
- Molecular Biology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Measurement Of Radiation (AREA)
Abstract
The invention belongs to detection Technology for Radioactive Substances fields, are related to a kind of UF6The verification measurement method of uranium quality and abundance in big tank.The verification measurement method is in empty UF6The UF of different known qualities is successively respectively charged into big tank6, respectively with neutron intensity measuring device in UF6Suitable location outside big tank measures UF6The total neutron intensity generated in big tank, the linear relation curve for returning acquisition uranium quality and total neutron intensity, i.e. acquisition scale equation；With the same UF that same neutron intensity measuring device is unknown in wherein uranium quality6Same suitable location outside big tank measures total neutron intensity, substitutes into scale equation and obtains the unknown UF of uranium quality6Total uranium quality in big tank.Utilize UF of the invention6The verification measurement method of uranium quality and abundance, can fast and accurately carry out UF at the scene in big tank6The verification measurement of uranium quality and abundance in big tank.
Description
Technical Field
The invention belongs to the technical field of radioactive substance detection, and relates to UF6A method for verifying and measuring the mass and abundance of uranium in a large tank.
Background
UF6The nuclear material is an important nuclear material, can be used for peaceful utilization of nuclear energy, and can also be used for manufacturing nuclear weapons and nuclear explosion devices, so that the nuclear material becomes a main monitoring object for international nuclear guarantee supervision, nuclear military provision control and national nuclear material control.
The verification and measurement technology of nuclear materials is an important technical means for effectively implementing the supervision of nuclear security and the control of the nuclear materials, and aims to timely and accurately acquire the information of the species, the quantity, the isotope composition/abundance and the like of the nuclear materials, thereby realizing the effective control of the nuclear materials. UF6Is one of the most important nuclear materials in the nuclear fuel cycle and is a key material for producing nuclear fuel. Therefore, UF was investigated6The verification measurement technology has important practical significance and practical application value for strengthening nuclear nonproliferation and nuclear guarantee supervision, effectively implementing national nuclear material control and ensuring the integrity and correctness of nuclear material declaration.
Most UF6All stored in standard steel vessels, and about 10 million UFs are reported worldwide6Large tanks, UF in transit each year6More than twenty thousand large tanks (two tons of low-concentration UF in each tank)6). For UF in these large tanks6It is important to perform the verification.
Public data displayNow, UF in steel vessels is adopted by international atomic energy agency6The verification measurement technique for nuclear materials is based primarily on periodic inspections by observers of the concentration or component manufacturing plants. The inspector will randomly draw portions UF at the facility site6Canister measurements were made to verify UF therein6Mass and abundance. Typical UF6The measurement technique is to use a gamma spectrometer to measure235185.7keV characteristic gamma-rays of U emission235U abundance, UF6The mass of (b) is determined by weighing the load.
These verification techniques are effective under certain conditions, but have deficiencies.
First, 185.7keV energy gamma ray penetration is weak for determining abundance, for UF6For large-volume objects such as storage tanks, the method can only detect the object information of the outermost layer (mainly the outermost layer of 1-2mm material, and actual UF6Tank diameters of up to tens of inches), measured UF6The objects are only a small fraction (less than one percent) of the material in the entire tank, so the measured information cannot be representative overall (unless uranium distribution is assumed to be uniform, consistent everywhere, with no hidden substitutions). Especially for UF that is not homogeneous6This deficiency can be problematic (non-verifiable) in the case of tanks (e.g., due to process variations or due to illegal material transfer scenarios) or hidden, fraudulent activities within the tank.
Another disadvantage is UF6The difference in can wall thickness can introduce measurement errors requiring wall thickness absorption corrections. Although the tank mass can be determined by weighing, it is not possible to determine if UF is present in the tank6The kind of material cannot be verified. Although the properties of all objects to be tested can be confirmed by extracting samples and analyzing, the method has the problems of large workload, high cost, long time consumption and radioactive waste liquid treatment.
Therefore, it is sought to establish that UF can be targeted in the field6The new technology and equipment for independently verifying large tanks has important practical applicationThe use value is high.
Disclosure of Invention
It is an object of the present invention to provide a UF6Method for verifying and measuring mass and abundance of uranium in large tank so as to rapidly and accurately carry out UF on site6Verified measurements of uranium mass and abundance in large tanks.
To achieve this, in a basic embodiment, the present invention provides a UF6A verification and measurement method for the quality and abundance of uranium in a large tank is as follows:
in the empty UF6UF with different known masses is sequentially and respectively filled into a large tank6Respectively at UF with neutron intensity measuring devices6Measuring UF at a suitable location outside the large tank6Obtaining a relation curve of uranium mass and total neutron intensity through linear regression of total neutron intensity generated in the large tank, namely obtaining a scale equation; identical UFs with identical neutron intensity measuring devices in which the uranium mass is unknown6Measuring total neutron intensity at the same suitable position outside the large tank, substituting into a scale equation to obtain UF with unknown uranium quality6Total uranium mass in the large tank;
or in the empty UF6The large tank is sequentially filled with uranium with the same known total mass and the same mass235U abundance but differences are known235U mass UF6Respectively at UF with neutron intensity measuring devices6Measuring UF at a suitable location outside the large tank6The total neutron intensity generated in the large tank is obtained by linear regression235Obtaining a scale equation by using a relation curve of the U mass and the total neutron intensity; using the same neutron intensity measuring equipment therein235Unknown U quality, total uranium quality and235identical UF with equal abundance of U6Measuring total neutron intensity at the same suitable position outside the large tank, and substituting the measured total neutron intensity into a scale equation to obtain235UF with unknown U quality6In large tanks235U mass;
or in an empty UF6The large tank is sequentially filled with uranium with the same known total mass and the same mass235U mass but different235UF of U abundance6Respectively at UF with neutron intensity measuring devices6Measuring UF at a suitable location outside the large tank6The total neutron intensity generated in the large tank is obtained by linear regression235Obtaining a scale equation by using a relation curve of the U abundance and the total neutron intensity; using the same neutron intensity measuring equipment therein235Unknown abundance of U, total uranium mass and235u of the same mass of the same UF6Measuring total neutron intensity at the same suitable position outside the large tank, and substituting the measured total neutron intensity into a scale equation to obtain235UF with unknown abundance of U6In large tanks235And U abundance.
The principle of the invention is as follows:
UF6UF in big tank6Will generate neutrons, UF6The leakage rate of the neutrons in the large tank is over 80 percent, and the neutrons have strong penetrability. For a certain mass of UF6The total neutron intensity of the emission can be calculated by the following formula (1):
T＝(c·f234+d·f238)m (1)
in formula (1):
t is total neutron intensity, and the unit is n/s;
m is the total uranium mass in g;
f234is composed of234The abundance value, i.e. the mass percentage value, of the U isotope;
f238is composed of238The abundance value, i.e. the mass percentage value, of the U isotope;
c. d is a coefficient.
For low enriched uranium, f238Is almost constant; at the same time, in the concentration process,234u is followed235U concentration and concentration, produced using the same feed for the same concentration processUF of (1)6In products234U/235The U ratio is the same. Thus, formula (1) can be further expressed as formula (2) below:
T＝(e+g·f235)m (2)
in formula (2):
t is total neutron intensity, and the unit is n/s;
m is the total uranium mass in g;
f235is composed of235The abundance value, i.e. the mass percentage value, of the U isotope;
e. g is a coefficient.
From the formula (2), UF6Under the condition that the abundance of each uranium isotope component is the same, the total uranium mass can be obtained by utilizing the total neutron intensity; conversely, if the total uranium mass is known and234U/235if the U ratio is constant, the total neutron intensity can be used to obtain the abundance of uranium. And, as can be seen from the formula (2), for UF from the same concentration plant6If UF is measured6In the pot235The abundance values of U are the same, the total neutron intensity and the uranium mass are measured (235U mass) is linear; if UF is measured6If the uranium in the tank has the same mass, the measured total neutron intensity is equal to that235The abundance of U,235The U mass is linear. In uranium enrichment processes234U is followed235U concentration and concentration, UF produced using the same feed for the same concentration process6In products234U/235The U ratio is the same. Thus, for the same concentration plant235The products with the same U abundance can be indirectly obtained in the tank by using the measured total neutron intensity235The mass of U and the total uranium mass; or when the same model UF6Under the condition that the tanks are fully filled (namely the total uranium has the same mass), the scale curve and the total neutron intensity which are obtained in advance can be utilized to obtain235Abundance and mass of U.
In a preferred embodiment of the process according to the invention,the invention provides a UF6Method for verifying and measuring the mass and abundance of uranium in a large tank, wherein said suitable location is at UF6The central line of the big tank is positioned.
In a preferred embodiment, the present invention provides a UF6Method for verifying and measuring the mass and abundance of uranium in a large tank, wherein the neutron intensity measuring device is3He tube-based thermal neutron detection equipment.
The invention has the advantages that UF of the invention is utilized6The method for verifying and measuring the mass and abundance of uranium in the large tank can quickly and accurately carry out UF on site6Verified measurements of uranium mass and abundance in large tanks.
The method only needs to be calibrated in advance, then the object to be measured is measured, the total neutron intensity is obtained, and UF can be obtained through calculation of a calibration equation6Total uranium mass in large tanks or235U abundance and mass. The method obtains UF in the whole large tank by using strong penetrability of neutrons6Information to prevent concealment and fraud inside the large tank, 100% UF in the large tank6Performing a global check, which effectively prevents UF in the national nuclear material control, international and security domains6The illegal transfer, loss and use of the material have important significance and practical application value.
Drawings
FIG. 1 shows the results of measurement in the embodiment235U abundance versus total neutron intensity.
FIG. 2 shows the results of measurement in the embodiment235U mass versus total neutron intensity.
Detailed Description
The following further describes embodiments of the present invention with reference to the accompanying drawings.
Exemplary UFs of the invention6The verification and measurement method for the mass and abundance of uranium in the large tank comprises the following steps:
in the empty UF6The large tank is sequentially filled with uranium with the same known total mass and the same mass235U abundance but differences are known235U mass UF6Respectively using neutron intensity measuring equipment (to)3He tube based thermal neutron detection apparatus) at UF6At a suitable location outside the large tank (at UF)6Tank centerline position) measurement UF6The total neutron intensity generated in the large tank is obtained by linear regression235Obtaining a scale equation by using a relation curve of the U mass and the total neutron intensity; using the same neutron intensity measuring equipment therein235The U mass is a nominal value, the total uranium mass is235Identical UF with equal abundance of U6Measuring total neutron intensity at the same suitable position outside the large tank, and substituting the measured total neutron intensity into a scale equation to obtain235UF with U mass at nominal value6In large tanks235A measure of U mass;
or,
in the empty UF6The large tank is sequentially filled with uranium with the same known total mass and the same mass235U mass but different235UF of U abundance6Respectively using neutron intensity measuring equipment (to)3He tube based thermal neutron detection apparatus) at UF6At a suitable location outside the large tank (at UF)6Tank centerline position) measurement UF6The total neutron intensity generated in the large tank is obtained by linear regression235Obtaining a scale equation by using a relation curve of the U abundance and the total neutron intensity; using the same neutron intensity measuring equipment therein235U abundance as nominal value, total uranium mass sum235U of the same mass of the same UF6Measuring total neutron intensity at the same suitable position outside the large tank, and substituting the measured total neutron intensity into a scale equation to obtain235UF with nominal U abundance6In large tanks235Measurement of U abundance.
FIG. 1 is a graph of measurements made using the exemplary method of the present invention described above235U abundance versus total neutron intensity, FIG. 2 is a plot of U abundance versus total neutron intensity measured using the exemplary inventive method described above235U mass versus total neutron intensity. The results of FIGS. 1 and 2 show that UF is not impaired when UF is used6UF in big tank6The total neutron intensity is dependent on the same loading235U abundance or235The U mass increases and there is a quasi-linear relationship between them.
Table 1 is the results of measurements using the exemplary inventive method described above.
Table 1 exemplary measurements of the method of the invention
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations. The foregoing examples or embodiments are merely illustrative of the present invention, which may be embodied in other specific forms or in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the invention should be indicated by the appended claims, and any changes that are equivalent to the intent and scope of the claims should be construed to be included therein.
Claims (3)
1. UF (ultra filtration factor)6A verification and measurement method for the quality and abundance of uranium in a large tank is characterized by comprising the following steps:
in the empty UF6UF with different known masses is sequentially and respectively filled into a large tank6Respectively at UF with neutron intensity measuring devices6Measuring UF at a suitable location outside the large tank6Obtaining a relation curve of uranium mass and total neutron intensity through linear regression of total neutron intensity generated in the large tank, namely obtaining a scale equation; identical UFs with identical neutron intensity measuring devices in which the uranium mass is unknown6Measuring total neutron intensity at the same suitable position outside the large tank, substituting into a scale equation to obtain UF with unknown uranium quality6Total uranium mass in the large tank;
or in the empty UF6The large tank is sequentially filled with uranium with the same known total mass and the same mass235U abundance but differences are known235U mass UF6Respectively at UF with neutron intensity measuring devices6Measuring UF at a suitable location outside the large tank6The total neutron intensity generated in the large tank is obtained by linear regression235Obtaining a scale equation by using a relation curve of the U mass and the total neutron intensity; using the same neutron intensity measuring equipment therein235Unknown U quality, total uranium quality and235identical UF with equal abundance of U6Measuring total neutron intensity at the same suitable position outside the large tank, and substituting the measured total neutron intensity into a scale equation to obtain235UF with unknown U quality6In large tanks235U mass;
or in the empty UF6The large tank is sequentially filled with uranium with the same known total mass and the same mass235U mass but different235UF of U abundance6Respectively at UF with neutron intensity measuring devices6Measuring UF at a suitable location outside the large tank6The total neutron intensity generated in the large tank is obtained by linear regression235Obtaining a scale equation by using a relation curve of the U abundance and the total neutron intensity; using the same neutron intensity measuring equipment therein235Unknown abundance of U, total uranium mass and235u of the same mass of the same UF6Measuring total neutron intensity at the same suitable position outside the large tank, and substituting the measured total neutron intensity into a scale equation to obtain235UF with unknown abundance of U6In large tanks235And U abundance.
2. A verification measurement method as claimed in claim 1, wherein: said suitable location is at UF6The central line of the big tank is positioned.
3. A verification measurement method as claimed in claim 1, wherein: the neutron intensity measurementThe measuring device is3HeA tube-based thermal neutron detection device.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810959927.6A CN108919334A (en) | 2018-08-22 | 2018-08-22 | A kind of UF6The verification measurement method of uranium quality and abundance in big tank |
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| CN201810959927.6A CN108919334A (en) | 2018-08-22 | 2018-08-22 | A kind of UF6The verification measurement method of uranium quality and abundance in big tank |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4765943A (en) * | 1985-11-29 | 1988-08-23 | Technology For Energy Corporation | Thermal neutron detectors and system using the same |
| CN103454669A (en) * | 2012-05-28 | 2013-12-18 | 中国原子能科学研究院 | Method for graduating barreled nuclear waste neutron measuring device |
| CN203365690U (en) * | 2013-05-13 | 2013-12-25 | 中国原子能科学研究院 | Neutron measurement device |
| CN106940448A (en) * | 2017-01-05 | 2017-07-11 | 中国原子能科学研究院 | A kind of Uranium enrichment plant's separative power on-line monitoring method |
| CN206906592U (en) * | 2017-05-24 | 2018-01-19 | 中国原子能科学研究院 | One kind measure235The device of U mass |
-
2018
- 2018-08-22 CN CN201810959927.6A patent/CN108919334A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4765943A (en) * | 1985-11-29 | 1988-08-23 | Technology For Energy Corporation | Thermal neutron detectors and system using the same |
| CN103454669A (en) * | 2012-05-28 | 2013-12-18 | 中国原子能科学研究院 | Method for graduating barreled nuclear waste neutron measuring device |
| CN203365690U (en) * | 2013-05-13 | 2013-12-25 | 中国原子能科学研究院 | Neutron measurement device |
| CN106940448A (en) * | 2017-01-05 | 2017-07-11 | 中国原子能科学研究院 | A kind of Uranium enrichment plant's separative power on-line monitoring method |
| CN206906592U (en) * | 2017-05-24 | 2018-01-19 | 中国原子能科学研究院 | One kind measure235The device of U mass |
Non-Patent Citations (3)
| Title |
|---|
| R. BERNDT .ET AL: "235U enrichment or UF6 mass determination on UF6 cylinders with non-destructive analysis methods", 《NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH A》 * |
| 刘国荣 等: "时间关联符合法测量铀材料质量和丰度的进一步研究", 《中国原子能科学研究院年报》 * |
| 吕学升 等: "CZT探测器测量铀浓缩厂容器中UF6铀丰度实验研究", 《中国核科学技术进展报告》 * |
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