DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Species A1 (FIGS. 2A-B) and B1 (the extraction system is included on a main loop) in the reply filed on 12/11/2025 is acknowledged.
The requirement for restriction among Groups I-III is withdrawn in view of the claims filed with the Preliminary Amendment dated 09/10/2025 (see Remarks, p. 4).
Status of Claims
Claims 14-18 are pending in the application and examined herein.
Information Disclosure Statement
Due to the copious number of references submitted on the aforementioned information disclosure statements and the breadth of the subject matter covered by these references, the references have been given a cursory review. If Applicant is aware that any of the cited references contain information that is directly related to patentability of the present invention, specific citations to the relevant subject matter should be provided.
Claim Objections
Claim 14 is objected to because of the following informalities: “fluidly coupled to piping of the molten salt loop” should be amended to recite “fluidly coupled to the piping of the molten salt loop” for proper antecedent basis (see prior recitation of “the molten salt loop comprises piping”). Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 14-18 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 14 is directed towards “[a] system”. The claim recites “a fuel salt system configured to circulate an irradiated fueled molten salt comprising fission products through a molten salt loop of a molten salt reactor system, wherein the molten salt loop comprises piping, an access vessel, a reactor core, a pump, and at least one heat exchanger”. It is unclear which of these features are intended to be positively recited features of the claimed “system” itself. For example, it is unclear if the “molten salt reactor system” is intended to be a positively recited feature of the claimed “system”. It is further unclear the relationship between the various recited structures. For example, it is unclear if the “fuel salt system” is intended to include or comprise the “molten salt loop” and associated components (e.g., “piping”, “access vessel”, etc.).
Any claim not explicitly addressed above is rejected because it is dependent on a rejected base claim.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim 14, as best understood, is rejected under 35 U.S.C. 103 as being unpatentable over “Fission Product Behavior in the Molten Salt Reactor Experiment” (“Compere”) in view of US Publication No. 2019/0371482 (“Benson”) and “Electrochemical behavior of La(III) on the zinc-coated W electrode in LiCl-KCl eutectic” (“Liu”).
Regarding claim 14, Compere (newly cited) (see FIGS. 2.1 (p. 3), 2.3 (p. 5)) discloses a system comprising:
a fuel salt system configured to circulate an irradiated fueled molten salt (“circulating fuel”, “fuel salt”) comprising fission products (“fission products”, “noble metals”) through a molten salt loop (“fuel circuit”, “main loop”) of a molten salt reactor system (“Molten Salt Reactor Experiment”, “MSRE”) (p. 16: “Molten-salt reactors generate the full array of fission products in the circulating fuel”), wherein the molten salt loop comprises piping (“piping”), an access vessel (“reactor vessel”), a reactor core (“MSRE core”), a pump (“centrifugal pump”, “fuel pump”), and at least one heat exchanger (“primary heat exchanger”) (p. 3: “The fuel circuit of the MSRE ... consisted essentially of a reactor vessel, a circulating pump, and the shell side of the primary heat exchanger, connected by appropriate piping”).
Compere does not appear to disclose a fission product extraction system. However, Compere discloses that the presence and accumulation of fission products in the molten salt has various consequences including providing fixed sources of decay heat and radiation, which makes maintenance more hazardous, and increasing the neutron poison effect (p. 2: “There are a number of consequences of fission product deposition. They provide fixed sources of decay heat and radiation. The afterheat effect will require careful consideration in design, and the associated radiation will make maintenance of related equipment more hazardous or difficult. Localization ... in the core could increase the neutron poison effect. There are indications that some fission products ... deposited on metals are associated with deleterious grain-boundary effects”). Benson (cited via Applicant-submitted IDS) (see FIGS. 1-4) is similarly directed towards a molten salt reactor system (102) in which an irradiated fueled molten salt comprising fission products is circulated through a molten salt loop ([0028], [0049]). Benson teaches a fission product extraction system (120, 200) fluidly coupled to piping of the molten salt loop ([0049], [0051]), the fission product extraction system comprising a pipe (205) connected to the piping of the molten salt loop ([0051]); and a metallic structure (230) extending from the pipe into the piping of the molten salt loop such that the metallic structure makes contact with the irradiated fueled molten salt ([0053]-[0054]); wherein the metallic structure is connected to a removable rod (235) of the fission product extraction system ([0053], [0059]); and wherein the fission product extraction system is operable to capture the fission products by redox reaction such that the fission products plate onto the metallic structure ([0054]). While Benson does not appear to explicitly teach a reducing agent, Benson teaches the fission products are plated on the metallic structure by an electrochemical reaction ([0054]). An electrochemical reaction involves a transfer of electrons, i.e., a redox reaction, which requires a reducing agent1. Benson further teaches molten salt reactor systems produce useful fission products and the fission product extraction system allows for the extraction and purification of fission products from the molten salt ([0001], [0048], [0055], [0065]). It would have therefore been obvious to a person having ordinary skill in the art before the effective filing date (“POSA”) to include Benson’s fission product extraction system in Compere’s system for the predictable purpose of removing and purifying fission products from the molten salt, as taught by Benson.
Benson does not appear to teach the metallic structure is partially coated in the reducing agent. However, Benson teaches the material comprising the metallic structure may be selected based on the desired reaction ([0055]). Liu (newly cited) is similarly directed towards a fission product extraction system operable to capture fission products (“fission products”, “FPs”, “La(III)”) in a molten salt by redox reaction with a metallic structure (“inert W electrode”) (Abstract, p. 206: “actinides along with active fission products (FPs) are anodically dissolved into the LiCl-KCl eutectic.... FPs gradually accumulated in the electrolyte.... To maintain efficient separation of [actinides] over FPs, the melt must be regularly purified or regenerated”, p. 214: “La(III) cations in the LaCl3-LiCl-KCl-ZnCl2 melts could be reduced on the Zn-coated W electrode by forming different La-Zn intermetallic compounds”). Liu teaches the metallic structure may be at least partially coated in a reducing agent (e.g., Zn) which participates in the redox reaction (Abstract). Liu further teaches the coated metallic structure allows for the extraction of lanthanum, which is a fission product (Abstract, p. 206: “Lanthanum, which exists in the form of La (III) cations in melt, is a typical rare-earth element and one of the most important FPs to be regenerated”). It would have therefore been obvious to a POSA to employ Liu’s coated metallic structure in the modified Compere’s system for the predictable purpose of extracting lanthanum, as suggested by Liu.
Claims 14 and 16, as best understood, are rejected under 35 U.S.C. 103 as being unpatentable over Compere in view of Benson and US Publication No. 2017/0294241 (“Dodson”).
Regarding claim 14, Compere (see FIGS. 2.1 (p. 3), 2.3 (p. 5)) discloses a system comprising:
a fuel salt system configured to circulate an irradiated fueled molten salt (“circulating fuel”, “fuel salt”) comprising fission products through a molten salt loop (“fuel circuit”, “main loop”) of a molten salt reactor system (“Molten Salt Reactor Experiment”, “MSRE”) (p. 16: “Molten-salt reactors generate the full array of fission products in the circulating fuel”), wherein the molten salt loop comprises piping (“piping”), an access vessel (“reactor vessel”), a reactor core (“MSRE core”), a pump (“centrifugal pump”, “fuel pump”), and at least one heat exchanger (“primary heat exchanger”) (p. 3: “The fuel circuit of the MSRE ... consisted essentially of a reactor vessel, a circulating pump, and the shell side of the primary heat exchanger, connected by appropriate piping”).
Compere does not appear to disclose a fission product extraction system. However, Compere discloses that the presence and accumulation of fission products in the molten salt has various consequences including providing fixed sources of decay heat and radiation which may make maintenance more hazardous or difficult and increasing the neutron poison effect (p. 2: “There are a number of consequences of fission product deposition. They provide fixed sources of decay heat and radiation. The afterheat effect will require careful consideration in design, and the associated radiation will make maintenance of related equipment more hazardous or difficult. Localization ... in the core could increase the neutron poison effect. There are indications that some fission products ... deposited on metals are associated with deleterious grain-boundary effects”). Benson (see FIGS. 1-4) is similarly directed towards a molten salt reactor system (102) in which an irradiated fueled molten salt comprising fission products is circulated through a molten salt loop ([0028], [0049]). Benson teaches a fission product extraction system (120, 200) fluidly coupled to piping of the molten salt loop ([0049], [0051]), the fission product extraction system comprising a pipe (205) connected to the piping of the molten salt loop ([0051]); and a metallic structure (230) extending from the pipe into the piping of the molten salt loop such that the metallic structure makes contact with the irradiated fueled molten salt ([0053]-[0054]); wherein the metallic structure is connected to a removable rod (235) of the fission product extraction system ([0053], [0059]); and wherein the fission product extraction system is operable to capture the fission products by redox reaction such that the fission products plate onto the metallic structure ([0054]). While Benson does not appear to explicitly teach a reducing agent, Benson teaches the fission products are plated on the metallic structure by an electrochemical reaction ([0054]). An electrochemical reaction involves a transfer of electrons, i.e., a redox reaction, which requires a reducing agent2. Benson further teaches molten salt reactor systems produce useful fission products and the fission product extraction system allows for the extraction and purification of fission products from the molten salt ([0001], [0048], [0055], [0065]). It would have therefore been obvious to a person having ordinary skill in the art before the effective filing date (“POSA”) to include Benson’s fission product extraction system in Compere’s system for the benefits thereof. Thus, modification of Compere in order to remove fission products from the molten salt, as suggested by Benson, would have been obvious to a POSA.
Benson does not appear to teach the metallic structure is partially coated in the reducing agent. However, it was known in the art to provide a reducing agent as a partial coating on a metallic structure. For example, Dodson (cited via Applicant-submitted IDS) (see FIGS. 1-3) is similarly directed towards a product extraction system (50) comprising a metallic structure (510) which participates in a redox reaction ([0037]-[0039]). Dodson teaches the metallic structure is partially coated in a reducing agent (512) which participates in a redox reaction with the molten salt ([0037]-[0039]). Dodson teaches providing the reducing agent as a coating allows for the consumption of the coating rather than the metallic structure itself ([0037]-[0040]). It would have therefore been obvious to a POSA to provide the reducing agent as a coating on the metallic structure, as taught by Dodson, in the modified Compere’s system for the predictable advantage of maintaining the metallic structure.
Regarding claim 16, Compere in view of Benson and Dodson teaches the system of claim 14. Dodson teaches the fission products are one or more of molybdenum-99, actinium-225, iodine-131, xenon-133, hydrogen-3, nitrogen-13, carbon-14, oxygen-15, fluorine-18, gallium-67, gallium-68, selenium-75, krypton-81m, strontium-89, yttrium-90, technetium-99m, indium-111, iodine-123, iodine-125, samarium-153, erbium-169, and radium-2233 ([0049]; see also Compere, Table 5.1; see also instant specification [0040]). Thus, Compere, modified to include Benson’s fission product extraction system and Dodson’s coating configuration, would have resulted in the features of claim 16.
Claims 15 and 17-18, as best understood, are rejected under 35 U.S.C. 103 as being unpatentable over Compere in view of Benson and Dodson further in view of US Publication No. 2020/0122109 (“Kruizenga”).
Regarding claim 15, Compere in view of Benson and Dodson teaches the system of claim 14. As discussed above, Benson teaches a redox reaction with the fission products ([0054]), but appears to be silent as to whether the reducing agent is released into the irradiated fueled molten salt upon the redox reaction. However, Benson teaches the material comprising the metallic structure may be selected based on the desired reactants that react with the metallic structure ([0055]). Kruizenga (cited via Applicant-submitted IDS) (see FIG. 1) is similarly directed towards a molten salt product extraction system comprising a metallic structure (121) comprising a reducing agent (e.g., beryllium) in contact with a molten salt ([0026], [0030]), wherein the product extraction system is operable to capture products in the molten salt by redox reaction between the reducing agent and the products such that the products plate onto the metallic structure ([0030]). Kruizenga teaches the reducing agent is released into the molten salt upon redox reaction with the products ([0030]). Kruizenga further teaches using beryllium as a reducing agent allows for the removal of corrosive impurities from the molten salt ([0026], [0028]-[0030]). Additionally, Compere discloses adding beryllium to the molten salt provides the advantages of controlling the oxidation state and chromium content of the fuel (p. 10: “an analysis for the oxidation of the fuel resulted in a U3+/U4+ value of 0.1%. Because values nearer 1% were desired, additions of metallic beryllium as rod (or powder) were made”, p. 13: “Beryllium was added to halt a rise in the chromium content of the fuel”, p. 136: “Additions of a reducing agent (beryllium metal), which inhibited the Cr2+ buildup”). It would have therefore been obvious to a POSA to use a beryllium reducing agent (which would release into the molten salt upon redox reaction), as taught by Kruizenga, for the benefits thereof. Thus, further modification of Compere in order to remove corrosive impurities, as suggested by Kruizenga, and to control the oxidation state and chromium content of the fuel, as suggested by Compere, would have been obvious to a POSA.
Regarding claim 17, Compere in view of Benson and Dodson teaches the system of claim 14. Benson does not appear to teach the reducing agent comprises at least one of beryllium, lithium, and zirconium. However, Benson teaches the material comprising the metallic structure may be selected based on the desired reactants that react with the metallic structure ([0055]). Kruizenga (see FIG. 1) is similarly directed towards a molten salt product extraction system comprising a reducing agent (121) in contact with a molten salt ([0026], [0030]), wherein the product extraction system is operable to capture products in the molten salt by redox reaction between the reducing agent and the products ([0030]). Kruizenga teaches the reducing agent at least one of beryllium, lithium, and zirconium ([0006], [0030], [0032]). Kruizenga further teaches using beryllium as a reducing agent allows for the removal of corrosive impurities from the molten salt ([0026], [0028]-[0030]). Additionally, Compere discloses adding beryllium to the molten salt provides the advantages of controlling the oxidation state and chromium content of the fuel (p. 10: “an analysis for the oxidation of the fuel resulted in a U3+/U4+ value of 0.1%. Because values nearer 1% were desired, additions of metallic beryllium as rod (or powder) were made”, p. 13: “Beryllium was added to halt a rise in the chromium content of the fuel”). It would have therefore been obvious to a POSA to use a beryllium reducing agent, as taught by Kruizenga, for the benefits thereof. Thus, further modification of Compere in order to remove corrosive impurities, as suggested by Kruizenga, and to control the oxidation state and chromium content of the fuel, as suggested by Compere, would have been obvious to a POSA.
Regarding claim 18, Compere in view of Benson and Dodson teaches the system of claim 14. Compere discloses the fission products include molybdenum (Table 5.1). As best understood by Examiner, a molten salt having molybdenum fission products (such as Compere’s molten salt) would include cationic molybdenum4 (see also [0051] of the instant specification). The modified Compere does not appear to teach the redox reaction involves neutral beryllium. However, Benson teaches the material comprising the metallic structure may be selected based on the desired reactants that react with the metallic structure ([0055]). Kruizenga (see FIG. 1) is similarly directed towards a molten salt product extraction system comprising a reducing agent (121) in contact with a molten salt ([0026], [0030]), wherein the product extraction system is operable to capture products in the molten salt by redox reaction between the reducing agent and the products ([0030]). Kruizenga teaches the reducing agent comprises neutral beryllium which participates in the redox reaction ([0006], [0030], [0032]). Kruizenga further teaches using beryllium as a reducing agent allows for the removal of corrosive impurities from the molten salt ([0026], [0028]-[0030]). Additionally, Compere discloses adding beryllium to the molten salt provides the advantages of controlling the oxidation state and chromium content of the fuel (p. 10: “an analysis for the oxidation of the fuel resulted in a U3+/U4+ value of 0.1%. Because values nearer 1% were desired, additions of metallic beryllium as rod (or powder) were made”, p. 13: “Beryllium was added to halt a rise in the chromium content of the fuel”). It would have therefore been obvious to a POSA to use a neutral beryllium reducing agent (which participates in the redox reaction with the fission products), as taught by Kruizenga, for the benefits thereof. Thus, further modification of Compere in order to remove corrosive impurities, as suggested by Kruizenga, and to control the oxidation state and chromium content of the fuel, as suggested by Compere, would have been obvious to a POSA.
The Applied References
For Applicant’s benefit, portions of the applied reference(s) have been cited (as examples) to aid in the review of the rejection(s). While every attempt has been made to be thorough and consistent within the rejection, it is noted that the prior art must be considered in its entirety by Applicant, including any disclosures that may teach away from the claims. See MPEP 2141.02(VI).
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Contact Information
Examiner Jinney Kil can be reached at (571) 272-3191, on Monday-Thursday from 7:30AM-5:30PM ET. Supervisor Jack Keith (SPE) can be reached at (571) 272-6878.
/JINNEY KIL/Examiner, Art Unit 3646
1 https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_Principles_of_Modern_Chemistry_(Oxtoby_et_al.)/Unit_4%3A_Equilibrium_in_Chemical_Reactions/17%3A_Electrochemistry/17.1%3A_Electrochemical_Cells#:~:text=In%20any%20electrochemical%20process%2C%20electrons,1%20.
2 https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_Principles_of_Modern_Chemistry_(Oxtoby_et_al.)/Unit_4%3A_Equilibrium_in_Chemical_Reactions/17%3A_Electrochemistry/17.1%3A_Electrochemical_Cells#:~:text=In%20any%20electrochemical%20process%2C%20electrons,1%20.
3 https://en.wikipedia.org/wiki/Fission_products_(by_element)
4 Clark, Austin David, et al. "Complexation of Mo in FLiNaK molten salt: insight from ab initio molecular dynamics." The Journal of Physical Chemistry B 125.1 (2020): 211-218.