Radioactive substances can emit ionizing radiation that can damage materials and harm people and animals over time. Radioactive gasses can be particularly dangerous as they can be inhaled and spread quickly through the air. The challenges of working with radioactive substances are magnified when the work includes heating and/or performing chemical processing with those radioactive substances. Chemical processing and heating are important parts of researching radioactive substances, and can also be used to produce reagents for commercial and/or industrial processes. Tools for working with radioactive gasses are specialized, and can include combinations of internally contained structures (e.g., containment vessels) and sealing to contain and redirect radioactive gasses to prevent their exposure to people and the environment.
In some aspects, the techniques described herein relate to an extraction system, the system including: a main body having a longitudinal axis, a first body end, and a second body end opposite and spaced apart along the longitudinal axis from the first body end, wherein the first body end includes a collar coupler for coupling the main body to a pierceable portion of a container defining a container chamber, the first body end defining a first channel extending along the longitudinal axis toward the second body end such that the first channel is in fluid communication with the pierceable portion when the container is coupled to the coupler, wherein the second body end defines a second channel extending along the longitudinal axis toward the first body end such that the second channel is in fluid communication with the first channel; and a piston having a first piston end and a second piston end opposite and spaced apart from the first piston end, the piston defining a piston channel extending from the first piston end to the second piston end, the piston including a hollow needle extending from the first piston end and in fluid communication with the piston channel, wherein the piston is slidably disposable within the second channel such that, when the piston slides through the second channel toward the first body end, the hollow needle of the piston extends through the first channel to pierce the pierceable portion of the container such that the container chamber of the container is in fluid communication with the second body end through the hollow needle, the piston channel, and the second channel.
In some aspects, the techniques described herein relate to a system, wherein, when the main body is oriented such that the longitudinal axis is parallel to a gravitational axis and the first body end is below the second body end, the piston is slidable through the second channel toward the first body end by gravity.
In some aspects, the techniques described herein relate to a system, wherein the pierceable portion of the container is a foil cap.
In some aspects, the techniques described herein relate to a system, further including a containment vessel, the containment vessel including an opening configured to couple to the main body.
In some aspects, the techniques described herein relate to a system, further including a heater disposed within the containment vessel.
In some aspects, the techniques described herein relate to a system, wherein the containment vessel further includes a cooling jacket.
In some aspects, the techniques described herein relate to a system, further including a sensor disposed within the containment vessel.
In some aspects, the techniques described herein relate to a system, further including a tube disposed in the hollow needle of the piston.
In some aspects, the techniques described herein relate to a system, further including a rod disposed within the tube and configured to retrieve a sample from the container through the hollow needle of the piston.
In some aspects, the techniques described herein relate to a system, wherein the collar coupler includes two or more collar portions are movable radially inwardly to contact a portion of the container.
In some aspects, the techniques described herein relate to a method of processing a material, the method including: providing the material in a container, wherein the container includes a pierceable portion; coupling the container to a main body, wherein the main body includes a piston configured to pierce the pierceable portion of the container, the piston including a hollow needle; coupling the main body to a containment vessel; heating the container to produce a processed material; piercing the pierceable portion of the container using the piston; and retrieving the processed material.
In some aspects, the techniques described herein relate to a method, wherein the processed material includes tritium, and a radioactive salt.
In some aspects, the techniques described herein relate to a method, wherein piercing the pierceable portion of the container includes rotating the main body.
In some aspects, the techniques described herein relate to a method, wherein the main body is oriented so that the piston is pulled toward the pierceable portion of the container by gravity.
In some aspects, the techniques described herein relate to a method, wherein retrieving the processed material includes inserting a tube or wire through the hollow needle.
In some aspects, the techniques described herein relate to a method, wherein retrieving the processed material includes venting a gas through the hollow needle.
In some aspects, the techniques described herein relate to a method, wherein the method further includes purging the container.
In some aspects, the techniques described herein relate to a method, wherein purging the container includes adding an inert gas to the container.
In some aspects, the techniques described herein relate to a method, wherein the inert gas includes argon.
In some aspects, the techniques described herein relate to a method, further including cooling at least one of the main body, the container, or the material using a cooling jacket.
It should be understood that the above-described subject matter may also be implemented as a computer-controlled apparatus, a computer process, a computing system, or an article of manufacture, such as a computer-readable storage medium.
Other systems, methods, features and/or advantages will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be protected by the accompanying claims.
The devices, systems, and methods disclosed herein provide for a working containment system for heating and off-gassing of radioactive samples where the release of airborne radionuclides is expected. The devices, systems, and methods disclosed herein allow for at least 20 mL of sample material to be positioned within a sealed, high temperature furnace chamber with an alignment tube. The capsule is subsequently pierced and vented using a weighted cylinder fitted with a stainless steel air needle for controlled off-gassing and measurement. Furnace heating may be conducted during any stage of assembly but is recommended while the vessel is sealed with cooling water being supplied to the external cooling jacket. Temperatures may safely reach between 500-800 degrees centigrade with cooling water being supplied at room temperature.
Various implementations include a sample extraction system. The system includes a main body and a piston. The main body has a longitudinal axis, a first body end, and a second body end opposite and spaced apart along the longitudinal axis from the first body end. The first body end includes a collar coupler for sealingly coupling the main body to a pierceable portion of a container defining a container chamber. The first body end defines a first channel extending along the longitudinal axis toward the second body end such that the first channel is in fluid communication with the pierceable portion when the container is coupled to the coupler. The second body end defines a second channel extending along the longitudinal axis toward the first body end such that the second channel is in fluid communication with the first channel. The piston has a first piston end and a second piston end opposite and spaced apart from the first piston end. The piston defines a piston channel extending from the first piston end to the second piston end. The piston includes a hollow needle extending from the first piston end and in fluid communication with the piston channel. The piston is slidably disposable within the second channel such that, when the piston slides through the second channel toward the first body end, the hollow needle of the piston extends through the first channel to pierce the pierceable portion of the container such that the container chamber of the container is in fluid communication with the second body end through the hollow needle, the piston channel, and the second channel.
In some implementations, the coupler includes two or more collar portions are movable radially inwardly to contact a portion of the container.
In some implementations, when the main body is oriented such that the longitudinal axis is parallel to a gravitational axis and the first body end is below the second body end, the piston is slidable through the second channel toward the first body end by gravity.
In some implementations, the pierceable portion of the container is a grafoil seal.
In some implementations, the system further includes a jacket defining a jacket chamber and including a lid for sealing the jacket chamber. The jacket chamber is configured to support the main body and a container coupled to the coupler of the main body in a fixed position. In some implementations, the system further includes a heater disposed within the jacket. In some implementations, the system further includes one or more sensors disposed within the jacket chamber.
Implementations of the present disclosure can include a main body that positions a container that is sealed with a cap, and a piston with a needle that can pierce the container sealed with the cap to open the container. This can be used for safe processing of toxic or radioactive materials within the container, as the container can be vented without requiring a person to manually unseal the container.
The first body end 114 can include a collar coupler for coupling the main body 110 to a container 120. The container can include a pierceable portion 122.
The pierceable portion 122 of the container 120 can optionally be a foil cap. A non-limiting example of a foil that can be used for the foil cap is an aluminum foil. Optionally, the pierceable portion 122 can be sealed to the container 120 using a grafoil material.
The first body end 114 can define a first channel 134 extending along the longitudinal axis 112 toward the second body end 116 such that the first channel 134 is in fluid communication with the pierceable portion 122 when the container 120 is coupled to the collar coupler 140. Optionally, the collar coupler can include two or more collar portions are movable radially inwardly to contact a portion of the container 120.
The second body end 116 can define a second channel 136 extending along the longitudinal axis toward the first body end 114 such that the second channel 136 is in fluid communication with the first channel 134.
The system 100 can further include a piston 150. The piston 150 can have a first piston end 152 and a second piston end 154. As shown in
Still with reference to
Optionally, the system 100 can be operated by orienting the main body 110 so that the longitudinal axis 112 of the main body 110 is parallel to the gravitational axis (i.e, the main body 110 is positioned so that the hollow needle 170 of the piston 150 in the second channel 136 is pointed toward the ground). As used herein the term “gravitational axis” refers to the direction of the force of gravity. The force of gravity can then cause the piston 150 to slide through the second channel 136. Implementations of the present disclosure can be configured so that the force of gravity on the piston 150 is sufficient to cause the hollow needle 170 to pierce the priceable portion 122 of the container 120. Optionally, the needle 170 and/or combination of needle 170 and piston 150 can be referred to herein as a “gravity rod” (for example, the gravity rod shown in
With reference to
In some implementations, the containment vessel 210 can include a heater 230. The heater can be used to heat the container 120 and/or any materials inside the container 120.
In some implementations, the containment vessel 210 can include a cooling jacket 220. The cooling jacket can extend partially or completely around the containment vessel 210 and/or main body 110. The cooling jacket 220 can be configured to allow a coolant to flow through the cooling jacket to keep the outer surfaces of the containment vessel 210 from reaching temperatures that could damage components of the main body and/or containment vessel.
In some implementations, the containment vessel 210 can include one or more sensors 250. Non-limiting examples of sensors 250 that can be used include signal wires, temperature sensors, thermocouples, and/or pressure sensors.
In some implementations, the system 100 can further include a rod and/or tube to collect samples from the container 120.
With reference to
At step 410, the method includes providing the material in a container, where the container includes a pierceable portion.
At step 420 the method includes coupling the container to a main body, wherein the main body comprises a piston configured to pierce the pierceable portion of the container, the piston comprising a hollow needle
At step 430 the method includes coupling the main body to a containment vessel.
At step 440 the method includes heating the container to produce a processed material. In some implementations, the method 400 can further include cooling the main body, the container, and/or the material using a cooling jacket. The cooling jacket can circulate a liquid or gas near the main body, container and/or material to cool any/all of the parts of the system.
At step 450 the method includes piercing the pierceable portion of the container using the piston. In some implementations, the piston can be caused to pierce the piercable portion of the container by the force of gravity. The main body can be turned so that gravity pulls the piston toward the container. Optionally, this can include rotating the main body so that the main body is positioned with the piston above the container.
At step 460 the method includes retrieving the processed material. In some implementations of the present disclosure, the method 400 can be used to generate tritium and the processed material can be tritium. Alternatively or additionally, the method 400 can be used to liquefy a radioactive salt, and the processed material can be the radioactive salt. The processed material can be retrieved at step 460 by inserting a tube and/or wire through the hollow needle of the piston to remove the processed material from the container. Optionally, gasses can be vented through the hollow needle of the piston.
In some implementations, the method can include purging the container using a gas. Optionally, the gas can be introduced through a tube inserted into the container. The gas can be an inert gas, and a non-limiting example of an inert gas that can be used in some implementations is argon.
Example implementations of the present disclosure were designed, built and tested.
An example implementation includes a radioactive tracer dilution (RTD) application for mass determination of irradiated fuel-bearing molten salt for nuclear material control and accounting (MC&A) scenarios. The irradiation experiment can be designed for a fuel-bearing chloride salt sample mixed with a radioactive tracer (22Na) of known activity and used for sampling the mixture for activation analysis.
The 22Na is an effective radioactive tracer to test the RTD concept [1]. This tracer was chosen because it undergoes beta+decay and is mainly produced by 24Mg(d,α)22Na reaction with an accelerator and a specific target. There can be two possibilities from which 22Na might be produced in a fission system, such as the double reactions, 6Li(n,α)3H and 20Ne(3H,n)22Na, which, however, has an extremely low yield in a fission reactor. The 22Na radioisotope could also be produced by spallation of argon gas, which, is more likely in nuclear detonation scenarios.
The radioisotope 22Na has known chemical compatibility with actinides and fission products in molten salt chloride and fluoride salts; it emits a 1274.54 keV gamma-ray that can be outside of the Compton plateau of many fission products. A known challenge is that it has an identified overlapping peak at 1274.43 keV from 154Eu. This interference can be resolved by measuring other gamma peaks from 154Eu, from which the 22Na gamma peak counts can be determined with the help of known branching ratio of 154Eu decay. However, there may be unknown interference if it is a real fission spectrum, which can only be investigated by irradiating a fuel-bearing salt to introduce fission products. It should be understood that the equipment and procedures described herein can be used to monitor and evaluate any types of fission gas production, off-gassing processes, and capture, and that the specific gasses, off-gassing processes, and systems and methods of fission gas production/capture discussed with reference to the present example are only non-limiting examples.
Implementations of the present disclosure include methods of salt preparation. A 13.8 g of MgCl2—KCl—UCl3 (DU) fuel salt was prepared. High purity (99.99%) MgCl2 and KCl were acquired through commercial vendors and mixed with a 0.3:0.7 molar ratio in terms of MgCl2:KCl. The UCl3 salt was synthesized by using DU metal rods and FeCl2 in MgCl2—KCl at ˜500° C. Salt samples were taken and measured by ICP-MS, and the UCl3 concentration was determined to be 15.15 wt % with 235 U concentration at 0.07 wt % and 238U concentration at 10.38 wt %. The FeCl2 concentration was 0.045 wt %. The total uranium in the sample had an overall average of 10.45 wt %. Following these measurements, the MgCl2—KCl—UCl2 salt mixture was packed in an argon glovebox and shipped.
Implementations of the present disclosure include methods of molten salt processing with off-gassing capabilities.
Implementations of the present disclosure include salt irradiation capsules that can be used as containers for the different materials and/or samples described herein.
The irradiation capsules for holding the solid and molten fuel salt mixture during post-irradiation heating can be designed with high purity fused quartz (99.98% SiO2) body which can be sealed with a flexible graphite gasket or Grafoil (GHL 2030L) with a minimum 99% carbon weight percentage.
PV=nRT (1)
The maximum temperatures observed in the designated irradiation facility due only to reactor core heating have been shown not to exceed 110° C. at full power (450 kWth). The melting point of the eutectic mixture of fuel salt has been determined to be approximately 430° C., which means the salt will remain solid during the irradiation period.
Conservative estimates of the salt activity levels for 10 grams of mixture were calculated and dose rates for gamma radiation were determined to be <30 mrem/hr at 10 cm from the source after 64 hours post-irradiation. Dose rates for beta radiation are estimated to be much higher but can be easily contained and shielded to prevent harm to personnel.
Once the activity levels are deemed safe, the capsule can be transferred to the glovebox where gamma spectra will be collected at 10 days and 100 days after irradiation. An example glovebox is shown in
After obtaining the salt gamma spectra, the subsequent experiments can focus on evaluating the RTD method. A salt sample containing the tracer can be irradiated using the same process in solid form. After irradiation, the capsule can be transferred to an airtight containment and heating vessel in the argon environment within a glovebox. The containment system can be designed so that the vessel may be rotated 90 degrees to allow a venting needle attached to a weighted piston necessary to drop onto the capsule head and puncture the seal for releasing gaseous fission products or vapor.
The released fission product gases, if any, will be vented through an off-gassing line to a decay tank outside the glovebox that will be kept at negative pressure. Activity of the entire sample will be measured. A line cooled with liquid nitrogen will serve as a cold trap to condense the fission product gases and a significant portion of the argon gas. The boiling points for xenon and krypton are −107.1° C. and 153.4° C. respectively while the liquid nitrogen will be held below −200° C. to condense and isolate the gases.
Once the off-gassing process is complete with possible fission product gases measured and analyzed, the salt sample will then be heated to 450° C. using a small heating plate (e.g., a kiln sold under the trade name Ultralite) situated within a containment vessel (
When the fuel salt mixture has melted, the venting system can be cycled a second time to flush out any remaining fission gases from the salt. These gases can be measured and analyzed. The system can be flushed with fresh argon, the central valve will be opened, and an extraction wire can be inserted through the venting piston and needle using a guide tube specially machined to mate with the topmost section of the weighted piston.
Afterwards, a small sample of the salt can be taken from the capsule and its mass and activity will be measured. Using Equation 2, the mass of the original fuel salt mixture (assumed unknown) can be determined through the RTD method.
A customized glovebox 1100 is illustrated in
In the study, the initial burn-up analysis was performed using the Oak Ridge Isotope GENeration (ORIGEN) and Monte-Carlo N-Particle transport (MCNP) codes. The simulation utilized flux information from the Ohio State University Research Reactor (OSURR) auxiliary irradiation facility (AIF) where the salt will ultimately be irradiated. After an irradiation time of 1 hour and cool down of 3 days, the results of the simulation indicated that the burnup of the 22Na tracer was 0.05% of the original 10 μCi added to the fuel-bearing salt. In comparison, MCNP determined a 0.025% burnup of 22Na after the same period. This result indicates that the tracer will retain sufficient activity for gamma spectrum analysis. Monitoring the production of additional radioactive isotopes can also be performed in the simulation, for example the production of fission products gases and isotopes that would cause spectral interference to the 22Na gamma peak. This analysis can provide an expectation of the type and amount of fission gases that would be released during the off-gassing process. ORIGEN shows timestamps for the production and decay of isotopes from start of irradiation through the 3-day decay period; an expected level of both stable and radioactive gases can be summed together. As the initial irradiation of the salt will be done in its solid phase, the solubility of gases in the solid salt was considered. MCNP simulations involving CINDER90 were used to determine quantities and activity levels following irradiation. As used herein, the following abbreviations are used:
The studied MCNP calculations were based on 100 cycles with 107 particles per sample. Flux values in the sample were determined to be 2.0×1013 n/cm2/sec with an error of 1.49% within a volume of 4.119 cm3 for 1 hour at 450 kWth. Isotopes of interest were noted including 154Eu which shares a gamma energy around the same 1274.54 keV peak as the 22Na tracer. The expected quantity of 154Eu after a 1-hour burn would be equivalent to 3.8×10−17 grams producing an approximate activity of 1×10−5 μCi.
Calculations using 10 micrograms of 22Na tracer proved to be much higher in activity levels than necessary. Therefore, another burn-up analysis was conducted with MCNP using an initial quantity of 0.016 micrograms. This resulted in 1.596×10−8 grams with an activity of 99.7 μCi after 3 days. This activity level was deemed to be much more manageable for post-irradiation analysis. Guided by these results, the amount of 22Na tracer to be added in the actual irradiation experiment could be greatly reduced.
The aluminum crimp seals 1500 and/or solid caps 1550 can be sealed using gaskets. An example gasket 1600 is shown in
The experimental implementation of a stainless steel jacketed container and heating mechanism shown in
The experimental implementation included a sample alignment holder with venting mechanism (also referred to herein as a “capsule alignment holder” or a collar coupler”).
The experimental implementation also included a venting and alignment apparatus for sampling within a central tube.
The study described herein included a test of piercing a foil seal using the force of gravity.
Implementations of the present disclosure include methods and systems for processing radioactive materials.
Implementations of the present disclosure include systems and methods to evaluate the feasibility of a radioactive tracer dilution (RTD) method of molten salt mass determination for accounting total mass of fuel salt in advanced liquid fueled molten salt systems. Implementations of the present disclosure also include methods of irradiating a real fuel bearing salt at a small research reactor, to evaluate the RTD method.
Alternatively or additionally, systems and methods described herein can be used to validate the RTD method for mass determination of fuel bearing molten salt at a small scale to evaluate the possibilities of its deployment in nuclear material accounting (NMA) scenarios such as those in advanced LFMSRs. Alternatively or additionally the systems and methods described herein can be used to address various measurement challenges that hinder the accurate determination of salt mass by RTD and/or to provide first hand experimental data to support RTD method for NMA in LFMSRs.
An example method according to the present disclosure can include preparing a small fuel bearing salt sample and irradiate it at a research reactor, mixing fuel bearing salt with a radioactive tracer of known activity, sampling the irradiated fuel bearing salt, measuring the mass and activity of each salt, sampling while correcting for any interference to tracer activity, and/or using the mass to activity ratio and the known original tracer activity, while accounting for any tracer burnup during irradiation, to calculate the known original fuel salt mass.
Implementations of the present disclosure include procedures for irradiation of fuel bearing salt sample and including the design of a salt container capsule, a salt heating apparatus and in situ gamma spectroscopy system, along with comprehensive radiation safety analyses is under preparation.
Implementations of the present disclosure include salt preparations. 13.8 g of MgCl2 KCl UCl3 fuel salt can be used. High purity 99.99% MgCl2 and KCl were acquired through commercial vendors and mixed with a 0.3:0.7 molar ratio in terms of MgCl2 KCl. The UCl3 concentration was determined to be 15.15 wt % with 235 U concentration at 0.07 wt % and 238U concentration at 10.38 wt %. The FeCl2 concentration was 0.045 wt % The total uranium in the sample had an overall average of 10.45 wt %
Tests were performed on a flexible graphite (grafoil) gasket.
The study of the example implementation included MCNP calculations based on 100 cycles with 107 particles per sample. Flux values in the sample were determined to be 2.0×1013 n/cm2/sec with an error of 1.49% within a volume of 4.119 cm3 for 1 hour at 450 kWth. Isotopes of interest were noted including 154Eu which shares a gamma energy around the same 1274.54 keV peak as the 22Na tracer. The expected quantity of 154Eu after a 1-hour burn would be equivalent to 3.8×10−17 grams producing an approximate activity of 1×10−5 μCi.
Calculations using 10 micrograms of 22NA tracer proved to be much higher in activity levels than necessary. Therefore, another burn-up analysis was conducted with MCNP using an initial quantity of 0.016 micrograms. This resulted in 1.596×10−8 grams with an activity of 99.7 μCi after 3 days. This activity level was deemed to be much more manageable for post-irradiation analysis. Guided by these results, the amount of 22Na tracer to be added in the actual irradiation experiment could be greatly reduced.
A number of example implementations are provided herein. However, it is understood that various modifications can be made without departing from the spirit and scope of the disclosure herein. As used in the specification, and in the appended claims, the singular forms “a,” “an,” “the” include plural referents unless the context clearly dictates otherwise. The term “comprising” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. Although the terms “comprising” and “including” have been used herein to describe various implementations, the terms “consisting essentially of” and “consisting of” can be used in place of “comprising” and “including” to provide for more specific implementations and are also disclosed.
Disclosed are materials, systems, devices, methods, compositions, and components that can be used for, can be used in conjunction with, can be used in preparation for, or are products of the disclosed methods, systems, and devices. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed that while specific reference of each various individual and collective combinations and permutations of these components may not be explicitly disclosed, each is specifically contemplated and described herein. For example, if a device is disclosed and discussed each and every combination and permutation of the device are disclosed herein, and the modifications that are possible are specifically contemplated unless specifically indicated to the contrary. Likewise, any subset or combination of these is also specifically contemplated and disclosed. This concept applies to all aspects of this disclosure including, but not limited to, steps in methods using the disclosed systems or devices. Thus, if there are a variety of additional steps that can be performed, it is understood that each of these additional steps can be performed with any specific method steps or combination of method steps of the disclosed methods, and that each such combination or subset of combinations is specifically contemplated and should be considered disclosed.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
This application claims the benefit of U.S. provisional patent application No. 63/401,424 filed on Aug. 26, 2022, and titled “GAS AND SAMPLE EXTRACTION SYSTEM FOR HIGH-TEMPERATURE IRRADIATED SAMPLES OF MOLTEN SALT, RADIOPHARMACEUTICAL, TRITIUM GAS, AND NOBLE GAS PRODUCTION,” the disclosure of which is expressly incorporated herein by reference in its entirety.
This invention was made with government support under DE-NE0009161 awarded by the Department of Energy. The government has certain rights in the invention.
Number | Date | Country | |
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63401424 | Aug 2022 | US |