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 and Claim Status
1. Applicant’s election without traverse of Invention I, Species A1 and claims 1-12, 14-15, 21 and 24 in the reply filed on 08/13/26 is acknowledged.
2. Claims 13, 22, 23, and 25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim.
3. Accordingly, claims 1-15 and 21-25 are pending with claims 13, 22, 23, and 25 withdrawn. Claims 1-12, 14-15, 21 and 24 are examined herein.
Claim Objections
4. Claims 3, 6, and 10 are objected to because of the following informalities. Appropriate correction is required.
In claim 3, the last line should refer to the subcritical core introduced in the previous line.
In claim 6, the recitation should be amended to “wherein the spallation target is uranium.”
In claim 10, the deleted word “the” needs to be replaced with an appropriate article, such as “a remaining portion.”
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
5. Claims 1-12, 14-15, 21, and 24 are rejected under 35 U.S.C. 112(a) as failing to comply with the enablement requirement. The claims contains subject matter which was not described in the Specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
6. Claim 1 recites a step of “removing volatile radioactive fission products from the molten-salt fuel” and claims 9, 11, 12, 21, and 24 recite further details of that step. The elected species of the claimed “removing” step is mass separation by centrifugal force. There is insufficient detail in the specification to enable a skilled artisan to practice the full scope of the “removing” step.
7. The claims are directed to “removing volatile radioactive fission products” from “molten-salt fuel” (claim 1) using “a centrifugal contactor” (claims 10, 24) “by mass using centrifugation” (claims 12, 21)
8. The disclosure1 provides inadequate description of this step, omitting all practical details, and providing only a generic, high-level overview:
[0016] In various embodiments, volatile radioisotopes can be removed using sparging (e.g., bubbling helium through the molten-salt fuel), spraying, (e.g., forcing the molten-salt fuel through a device such as a nozzle that forms many small streams that break up into droplets with large surface area compared to volume, thereby increasing the evaporation of the volatile radioisotopes), separating actinides by mass or using a liquid metal medium, and/or other techniques.
[0031] In various embodiments, volatile fission products, including volatile radioisotopes, can be removed using any one or any combination of: sparging, as known in chemistry and also known as gas flushing in metallurgy, which is a technique in which a gas is bubbled through a liquid in order to remove other dissolved gas(es) and/or dissolved volatile liquid(s) from that liquid, thus a method of degassing (e.g., bubbling helium through the molten salt fuel); spraying, described in paragraph was used in the Oak Ridge National Laboratory (ORNL) Molten-Salt Reactor Experiment (MSRE) (e.g., as discussed in Taylor et al., “Mu*STAR ADSR Fuel Conversion Facility Evaluation and Cost Analysis,” ORNL/TM-2018/989, Oak Ridge National Laboratory, 2019, 5); separating actinides by mass or using a liquid metal medium, as discussed below with reference to FIGS. 3 and 4; and other techniques (e.g., letting a thin layer of molten-salt liquid flow over a heated flat plate to increase the evaporation rate of gases from the molten-salt fuel).
[0042] FIG. 4 illustrates an embodiment of a separation device 434 for isolating light fission products in a system for continuous removal of fission products, such as system 332. Separation device 434 can be an example of separation device 334. In the illustrated embodiment, separation device 434 includes a centrifugal contactor (also known as centrifugal separator, centrifugal extractor, or annular centrifugal contactor) 440. Centrifugal contactor 440 is a mass separation device that can isolate the light fission products from the side stream by mass using centrifugation.
Figs. 3 and 4 depict a “separation device” 334 and a “centrifugal contactor” 440 as black boxes with no structural details.
9. The disclosure does not provide any cited prior art pertaining to separation by mass of fission products from molten salt, nor any citations that describe a “a centrifugal contactor (also known as centrifugal separator, centrifugal extractor, or annular centrifugal contactor)” (as described at [0042]). A search indicates that a centrifugal extractor “uses the rotation of the rotor inside a centrifuge to mix two immiscible liquids outside the rotor and to separate the liquids in the field of gravity inside the rotor”2 Yet there is no description in the disclosure as filed as to what second liquid is added to the molten-salt fuel to achieve such a separation. The examiner can find no specific information pertaining to separation of “volatile radioactive fission products” from “molten-salt fuel” by a centrifugal contactor that would enable a skilled artisan to practice the claimed invention.
10. To be enabling, the disclosure, as filed, must be sufficiently complete to enable a person of ordinary skill in the art to make and a use the full scope of the claimed invention without undue experimentation. It is the Examiner’s position that an undue amount of experimentation would be required to produce an operative embodiment of the claimed invention.
To determine whether a given claim is supported in sufficient detail (by combining the information provided in the disclosure with information known in the art) such that any person skilled in the art could make and use the invention as of the filing date of the application without undue experimentation, at least the following factors should be included:
(A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
This standard is applied in accordance with the U.S. Federal Court of Appeals decision In re Wands, 858 F.2d at 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988). See also United States v. Telectronics Inc., 857 F.2d 778, 785, 8 USPQ2d 1217, 1223 (Fed. Cir. 1988), cert. denied, 490 U.S. 1046 (1989).
10. Reviewing the aforementioned Wands factors, the evidence weighs in favor of a finding that undue experimentation would be necessary to make and use the claimed invention, and therefore, a determination that the disclosure fails to satisfy the enablement requirement. Specifically:
(A) The breadth of the claims: The claims merely recite broad, generic separation steps and fail to recite particular structure and parameters associated with the “removing” step of claim 1. The claims are directed to “removing volatile radioactive fission products” from “molten-salt fuel” (claim 1) using “a centrifugal contactor” (claims 10, 24) “by mass using centrifugation” (claims 12, 21). See MPEP § 2164.08.
(B) The nature of the invention and the level of skill: The invention is “a method for nuclear power generation” (claim 1) and pertains to fission of a molten-salt fuel in a subcritical, accelerator-driven reactor and subsequent treatment of the fissioned molten-salt fuel. Consequently a skilled artisan would need to be educated in both nuclear reactor physics and the concepts of physical and chemical separation methodology involved in fuel processing. These are not significant factors in the enablement analysis. See MPEP § 2164.05(a) and (b).
(C) The state of the prior art: The specification does not establish and a search did not reveal that the claimed subject matter of separating fission products from molten-salt fuel by centrifugation (see paragraph 7 above) is well-known in the prior art sufficiently to allow omission of practical details of the claimed subject matter from the disclosure. See MPEP § 2164.05(a). “The specification need not disclose what is well-known to those skilled in the art and preferably omits that which is well-known to those skilled and already available to the public.”
(E) The level of predictability in the art: Based on the lack of prior art specifically pertaining to the claimed separation of volatile radioactive fission products from molten-salt fuel, there does not appear to be any predictability in the art. See MPEP § 2164.03.
(F) The amount of direction provided by the inventor: The disclosure fails to set forth any practical details of the claimed “removing” step. See MPEP § 2164.03.
(G) The existence of working examples: There is no evidence the invention has been demonstrated or reliably reproduced. See MPEP § 2164.02.
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure: The quantity of experimentation needed is unreasonable because the practical guidance provided is insufficient to enable one to accomplish the claimed step of removing volatile radioactive fission products” from “molten-salt fuel” by mass centrifugation. The disclosure fails to disclose the specific “centrifugal contactor” and the operating parameters of such a device that are operable to achieve the claimed method. One would need to conduct a full research and development program to determine such information. See MPEP § 2164.06.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
11. Claims 5, 9-12, 14-15, and 21 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
12. Regarding claim 5, the recitation “the nuclear power generation” lacks antecedent basis.
13. Regarding claim 9 (and dependents 10-12, 14, and 15), the recitation “light fission products” is unclear in view of the claim 1 recitation “volatile radioactive fission products.” Are the “light fission products” removed in addition to the ““volatile radioactive fission products”? Are the “light fission products” a subset of the “volatile radioactive fission products”? Or are the “volatile radioactive fission products” a subset of the “light fission products”? Are the two terms intended to encompass the same subject matter? Further, the recitation “light” is a relative term which renders the claim indefinite. The term is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
14. Regarding claim 15, the recitation “extracting one or more isotopes” from the “isolated light fission products” is unclear. “Light fission products” themselves are “isotopes,” so it is unclear what is extracted in this step.
15. Regarding claim 12, the recitation is unintelligible. At a minimum, the recitation of claim 1 is directed to “removing volatile radioactive fission products.” Fission products, by definition, are not actinides. The claim is inconsistent with the disclosure, which does not describe in any manner “separating actinides” from one another. Further, there appears to be some punctuation and/or grammatical errors in the claim that preclude any meaningful interpretation
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 (or as subject to pre-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.
For applicant's benefit, the portions of the reference(s) relied upon in the below rejections have been cited to aid in the review of the rejections. While every attempt has been made to be thorough and consistent within the rejection, it is noted that prior art must be considered in its entirety, including disclosures that teach away from the claims. See MPEP 2141.02 VI.
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.
16. Claims 1-8 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Johnson, R. P., et al. "Mu* STAR: An Accelerator-Driven Subcritical Modular Reactor." Proc. NAPAC’19 (2019): 163-165 in view of Bernardin, US 2003/0179843.
17. Regarding claims 1-2, Johnson discloses a method for nuclear power generation, comprising: operating an accelerator-driven subcritical reactor using molten-salt fuel (see Fig. 1 and paras. 1-2 of “Technical Description”) and removing volatile radioactive fission products from the molten-salt fuel continuously during the operation of the reactor (see Fig. 2 para. 3 of “Technical Description”) to maintain an amount of the volatile radioactive fission products in the reactor below a threshold corresponding to a safety limit for accidental release of radioactive materials, wherein the safety limit is required by a government regulation (intended use recitation; the step performed by Johnson is capable of this purpose; see “Safety”).
Johnson is silent as to monitoring the criticality of the reactor. Bernardin teaches a method of operating an accelerator-driven subcritical reactor (see Abs.) including continuously monitoring the operation of the reactor ([0067]) to ensure subcriticality (intended use recitation; the step performed by Bernardin is capable of this purpose; see[0070], [0076]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the monitoring step of Bernardin with the method of Johnson for the predictable advantages of enabling a reduction in accelerator size ([0096] and providing a fail safe to eliminate risk of loss of control ([0097]).
18. Regarding claim 3, Johnson as combined with Bernadin makes claim 1 obvious. Johnson further discloses a method wherein operating the accelerator-driven subcritical reactor comprises operating a superconducting linear particle accelerator and a small modular reactor, the superconducting linear particle accelerator configured to generate a proton beam to be injected into the small modular reactor, the small modular reactor including a subcritical core and a spallation target positioned in a subcritical core (see Fig. 2 and para 1. Of “Technical Description”).
19. Regarding claim 4, Johnson as combined with Bernadin makes claim 1 obvious. Bernardin further teaches a method wherein continuously monitoring the operation of the reactor comprises measuring a rate of neutron production in the reactor as a function of time during a measurement period after a pulse of neutrons is produced in the reactor by a proton bunch of the proton beam ([0067-8]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the monitoring step of Bernardin with the method of Johnson for the reasons stated above.
20. Regarding claim 5, Johnson as combined with Bernadin makes claim 1 obvious. While Johnson does not explicitly disclose a step of manufacturing the small modular reactor in one or more factories remote from a site of the nuclear power generation, it strongly suggests that such a step is intrinsically present. Johnson states “Our concept is to install Mu*STAR accelerator-driven subcritical systems as existing LWR sites (see Fig. 1 and para. 1 of “Concepts and Innovations”). Because “existing LWR sites” do not have the capability to “manufacture a small modular reactor,” it logically follows that Johnson makes obvious the step of manufacturing the modular reactor elsewhere before it can be installed at the LWR site.
21. Regarding claim 6, Johnson as combined with Bernadin makes claim 1 obvious. Johnson further discloses that the spallation target is uranium (see para. 1 of “Introduction”).
22. Regarding claim 7, Johnson as combined with Bernadin makes claim 1 obvious. Johnson further discloses operating one or more additional small modular reactors with the superconducting linear particle accelerator being used to drive the small modular reactor and the one or more additional small modular reactors (see Fig. 1).
23. Regarding claim 8, Johnson as combined with Bernadin makes claim 1 obvious. Johnson further discloses housing the accelerator-driven subcritical reactor in a reactor containment (see Fig. 1 + Fig. 2).
24. Regarding claim 21, Johnson as combined with Bernadin makes claim 1 obvious. Johnson further discloses removing the volatile radioactive fission products from the molten-salt fuel by sparging (see Fig. 2 and para. 2 of “Technical Description”).
25. Claims 9-12, 14, and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Johnson, R. P., et al. "Mu* STAR: An Accelerator-Driven Subcritical Modular Reactor." Proc. NAPAC’19 (2019): 163-165 in view of Bernardin, US 2003/0179843, in further view of Woolley, US 2015/0078504.
26. Regarding claim 9, Johnson as combined with Bernadin makes claim 1 obvious. While Johnson does disclose removing volatile radioactive fission products including separating the light fission products from the actinides performed within the reactor containment while the reactor is operating (see Figs. 1, 2 and paras. 1 and 2 of “Features and advantages”). Johnson does not disclose producing a side stream of the molten-salt fuel flowing out of the reactor (see Fig. 2). Wolley teaches a method of operating an accelerator driven subcritical reactor using molten-salt fuel ([0021]) comprising removing volatile radioactive fission products by producing a side stream of the molten-salt fuel flowing out of the reactor, the side stream including light fission products and actinides; separating the light fission products from the actinides; and returning the actinides to the reactor (see Fig. 1 and [0057-9]) wherein the receiving producing, separating, and returning are performed while the reactor is operating ([0071]. One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the steps taught by Woolley with the method of Johnson because Woolley teaches that its fuel processing steps predictably allow for operating the reactor continuously without shut down and enables “harvesting 100% of [the fuel’s] fission energy” ([0085]). Additionally, it would have been obvious to a skilled artisan to perform the steps taught by Woolley in the method of Johnson within Johnson’s reactor containment so as to mitigate the risks caused by handing the highly radioactive actinide containing molten-fuel salt without the radiological protection provided by the containment.
27. Regarding claim 10, Johnson as combined with Bernadin and Woolley makes claim 9 obvious. Johnson additionally teaches leaving the actinides in the side stream; and injecting the side stream including the actinides back to the reactor for transmutation of a portion of the actinides and destruction of a remaining portion of the actinides (see Fig. 1 and [0085]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the steps taught by Woolley with the method of Johnson for the reasons stated above.
28. Regarding claims 11 and 12, Johnson as combined with Bernadin and Woolley makes claim 9 obvious. Woolley additionally teaches isolating the light fission products from the side stream using contactor that isolates the light fission products from the side stream by mass using centrifugation ([0059]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the steps taught by Woolley with the method of Johnson for the reasons stated above.
29. Regarding claims 14 and 15, Johnson as combined with Bernadin and Woolley makes claim 11 obvious. Johnson further discloses a method further comprising removing the isolated light fission products from the reactor containment, the removed light fission products having a radiotoxicity lifetime for which a geological repository is not required and , further comprising extracting one or more isotopes from the isolated light fission products using fractional distillation (see Fig. 2 and para. 3 of “Technical Description”).
30. Regarding claims 21 and 24, Johnson as combined with Bernadin makes claim 1 obvious. Johnson does not disclose separating actinides by mass. Wolley teaches a method of operating an accelerator driven subcritical reactor using molten-salt fuel ([0021]) comprising separating actinides by mass using a centrifugal contactor (see Fig. 1 and [0057-9]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the steps taught by Woolley with the method of Johnson because Woolley teaches that its fuel processing steps predictably allow for operating the reactor continuously without shut down and enables “harvesting 100% of [the fuel’s] fission energy” ([0085]).
Interviews
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Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHARON M DAVIS whose telephone number is (571)272-6882. The examiner can normally be reached Monday - Thursday, 7:00 - 5:00 pm ET.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jack Keith can be reached at 571-272-6878. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SHARON M DAVIS/Primary Examiner, Art Unit 3646
1 Citations here refer to the published application US 2025/0046483A1.
2 “Centrifugal extractor” attached hereto.
