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. Claim 1, as amended, is directed to non-elected species B8, depicted in Fig. 17B. The elected species (see Figs. 1A and 3B) is a reactor system comprising a single nuclear reactor having a heat exchanger therein, the heat exchanger in communication with a circulation system comprising a coolant pump and a coolant loop heat exchanger. In contrast, the non-elected embodiment depicted at Fig. 17B includes multiple reactors connected in parallel to an electrical conversion system, features that are not present in the elected embodiment. In the non-elected embodiment the multiple heat exchangers are connected to a common circulation loop including the electrical conversion system. Prior art applicable to the elected, and already searched and examined invention, is not reasonably applicable to the non-elected embodiment. Thus, a serious search and examination burden exists. In a brief phone call conducted on 01/14/26, the examiner responded to Applicant’s representative questioning whether it might be possible that the Fig. 17B embodiment could be examined along with the elected embodiment. The examiner indicated that arguments to that effect would be considered but advised that any amendments to the claims to recite limitations present in the non-elected embodiment should be placed in dependent claims. No arguments indicating why Applicant believes the non-elected species is not patentably distinct from the elected species were included in the response dated 03/05/26 and the features directed to the non-elected species of Fig. 17B are recited in independent claim 10.
2. Accordingly, claims 10-11 and 21-25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected species, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 10/20/25. Claims 12-14 were previously withdrawn.
3. The response dated 03/09/26 cancelled claims 1-9 and 15.
4. Claims 10-14 and 21-35 are pending with claims 10-14 and 21-25 withdrawn. Claims 26-31 are examined herein.
Information Disclosure Statement
5. The information disclosure statement filed 03/09/26 fails to comply with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. It has been placed in the application file, but the information referred to therein has not been considered.
Claim Rejections - 35 USC § 103
6. 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 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.
7. 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.
8. 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.
9. Claims 26, 27, 29, 31, and 35 are rejected under 35 U.S.C. 103 as being unpatentable over Abbott et al., US2017/0316841 in view of Geist, US3,486,977, in further view of Benson et al., US 2023/0395270.
10. Regarding claims 26, 27, and 29, Abbot discloses a molten salt reactor system (Abs., [0012]; Fig. 3B) comprising an in-core heat exchanger (310) comprising a heat exchange array defining a plurality of fuel channels therethrough (see Fig. 3C and Fig. 5; [0016]), wherein the in-core heat exchanger is configured to permit the fuel to undergo fission reactions therein (see Fig. 3B; the examiner notes that this functional imitation is necessarily present in any in-core heat exchanger); a coolant circulation system configured to provide a continuous circulation of a reduced temperature coolant to the in-core heat exchanger, and to receive a continuous circulation of an elevated temperature coolant from the in-core heat exchanger (([0039]); and a fuel circulation system configured to provide a continuous circulation of an elevated temperature fuel to each of the plurality of fuel channels, and to receive a continuous circulation of a reduced temperature fuel from each of the plurality of fuel channels ([0040]).
Although Abbot discloses a shell-and-tube heat exchanger, Abbot expressly suggests such a heat exchanger could be replaced with a printed circuit heat exchanger ([0012]), making such a modification obvious to a skilled artisan at the time of the invention/filing.
Abbott does not disclose that its in-core heat exchanger is formed from a moderator material.
Geist teaches a fluid fuel nuclear reactor (Abs.; Fig. 1) comprising an in-core heat exchanger (1)
formed from a graphite moderator material (column 2, lines 29-30) and defining a plurality of fuel channels (2) and a plurality of coolant channels (3) therethrough, the plurality of coolant channels being fluidically isolated from the plurality of fuel channels (see Fig. 1 and column 2, lines 50-63); wherein the in-core printed circuit heat exchanger is configured to permit the fuel to undergo fission reactions therein (see Fig. 1; the examiner notes that this functional imitation is necessarily present in any in-core heat exchanger), and transfer heat from the elevated temperature fuel to the reduced temperature coolant via the moderator material (column 2, lines 32-35).
One of ordinary skill in the art at the time of the invention/filing would have found it obvious to apply the in-core moderating heat exchanger of Geist to the reactor of Abbot for the predictable advantage of providing a thermal spectrum reactor that better utilizes fission neutrons (see column 2, line 29; see also Abbott at [0013]).
Benson teaches that in addition to graphite, composite materials such as a SiC combined with graphite or diamond are also suitable moderating materials for use in a molten salt reactor (see [0017-20], [0185). Thus, one of ordinary skill in the art at the time of invention/filing would have found it obvious to employ such a composite material in the heat exchanger of Abbot as modified by Geist. It has been held to be within the general skill of a worker in the art to select known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. “It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art.” In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980) (citations omitted) and MPEP §2144.06.
11. Regarding claim 31, Abbot as modified by Geist and Benson makes claim 26 obvious. Geist further teaches an in-core heat exchanger wherein the plurality of fuel channels and the plurality of coolant channels cooperate to establish a cross flow of the fuel relative to the coolant (see Fig. 1). One of ordinary skill in the art at the time of invention/filing would have found it obvious to modify Abbot for the reasons stated above.
12. Regarding claim 35, Abbot as modified by Geist and Benson makes claim 26 obvious. Abbott further discloses a molten salt reactor wherein the coolant comprises a molten salt and wherein the fuel comprises a molten fuel salt ([0013-4]).
13. Claims 26 and 28 are rejected under 35 U.S.C. 103 as being unpatentable over Abbott et al., US2017/0316841 in view of Geist, US3,486,977, in further view of Hamelin, R. Doug, and G. O. Hayner. “Next Generation Nuclear Plant Materials Selection and Qualification Program Plan.”
14. Regarding claims 26 and 28, Abbot discloses a molten salt reactor system (Abs., [0012]; Fig. 3B) comprising an in-core heat exchanger (310) comprising a heat exchange array defining a plurality of fuel channels therethrough (see Fig. 3C and Fig. 5; [0016]), wherein the in-core heat exchanger is configured to permit the fuel to undergo fission reactions therein (see Fig. 3B; the examiner notes that this functional imitation is necessarily present in any in-core heat exchanger); a coolant circulation system configured to provide a continuous circulation of a reduced temperature coolant to the in-core heat exchanger, and to receive a continuous circulation of an elevated temperature coolant from the in-core heat exchanger (([0039]); and a fuel circulation system configured to provide a continuous circulation of an elevated temperature fuel to each of the plurality of fuel channels, and to receive a continuous circulation of a reduced temperature fuel from each of the plurality of fuel channels ([0040]).
Although Abbot discloses a shell-and-tube heat exchanger, Abbot expressly suggests such a heat exchanger could be replaced with a printed circuit heat exchanger ([0012]), making such a modification obvious to a skilled artisan at the time of the invention/filing.
Abbott does not disclose that its in-core heat exchanger is formed from a moderator material.
Geist teaches a fluid fuel nuclear reactor (Abs.; Fig. 1) comprising an in-core heat exchanger (1)
formed from a graphite moderator material (column 2, lines 29-30) and defining a plurality of fuel channels (2) and a plurality of coolant channels (3) therethrough, the plurality of coolant channels being fluidically isolated from the plurality of fuel channels (see Fig. 1 and column 2, lines 50-63); wherein the in-core printed circuit heat exchanger is configured to permit the fuel to undergo fission reactions therein (see Fig. 1; the examiner notes that this functional imitation is necessarily present in any in-core heat exchanger), and transfer heat from the elevated temperature fuel to the reduced temperature coolant via the moderator material (column 2, lines 32-35).
One of ordinary skill in the art at the time of the invention/filing would have found it obvious to apply the in-core moderating heat exchanger of Geist to the reactor of Abbot for the predictable advantage of providing a thermal spectrum reactor that better utilizes fission neutrons (see column 2, line 29; see also Abbott at [0013]).
Hamelin teaches that in addition to graphite, composite materials such as a Cf/SiC composite diamond are also suitable moderating materials for “structural applications” in nuclear reactors (see pp. 32-34), noting that such materials are stronger and more fracture resistant than graphite. Thus, one of ordinary skill in the art at the time of invention/filing would have been motivated to employ the Cf/SiC composite material taught by Hamelin in the heat exchanger of Abbot as modified by Geist. It has been held to be within the general skill of a worker in the art to select known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. “It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art.” In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980) (citations omitted) and MPEP §2144.06.
15. Claim 30 is rejected under 35 U.S.C. 103 as being unpatentable over Abbott et al., US2017/0316841 in view of Geist, US3,486,977 and Benson et al., US 2023/0395270, in further view of Zhang et al., US 2022/0375636.
16. Regarding claim 30, Abbot as modified by Geist and Benson makes claim 26 obvious. Abbott further discloses a molten salt reactor wherein the fuel circulation system comprises a circulation driver (312A) configured to continuously provide fuel to the in-core heat exchanger (Fig. 3B), which in the combination with Geist comprises a plurality of fuel channels (2). One of ordinary skill in the art at the time of invention/filing would have found it obvious to modify Abbot for the reasons stated above.
Abbott is silent as to the details of its coolant circulation system. The examiner believes such systems are well-known in the art (e.g., see the Wikipedia article entitled “Molten-salt reactor” attached hereto). Nonetheless, Zhang teaches a molten- salt reactor system (Fig. 1; Abs., [0002]) wherein the coolant circulation system comprises a coolant system heat exchanger (4-3) configured to transition the coolant from the elevated temperature coolant to the reduced temperature coolant for continuous circulation with an in-core heat exchanger (1-5).
One of ordinary skill in the art at the time of invention/filing would have found it obvious to employ a heat exchanger in the coolant circulation loop of Abbot for the predictable purpose of providing coolant at a temperature range effective for accepting heat from the fuel salt.
17. Claims 32-34 are rejected under 35 U.S.C. 103 as being unpatentable over Abbott et al., US2017/0316841 in view of Geist, US3,486,977 and Benson et al., US 2023/0395270, in further view of Freeman, et al., US2022/0051816.
18. Regarding claims 32-34, Abbot as modified by Geist and Benson makes claim 26 obvious. Abbot does not disclose the structural details of the printed circuit heat exchanger it suggests to be an obvious modification of its shell-and-tube heat exchanger. Freeman teaches an in-core printed circuit heat exchanger ([0035-6], [0059]) comprising a first stack of heat exchange layers associated with a plurality of primary fluid channels, and a second stack of heat exchange layers associated with a plurality of secondary fluid channels ([0053]), wherein the first stack of heat exchange layers comprises one or more layers interposed with layers of the second stack of heat exchange layers (Fig. 1A), wherein the first stack of heat exchange layers and the second stack of heat exchange layers are, collectively, portions of an integrally constructed, one-piece structure ([0062-3]).
One of ordinary skill in the art at the time of invention/filing would have found it obvious to apply the PCHE structure taught by Freeman-to the in-core heat exchanger of Abbot as modified by Geist’s moderator material in-core heat exchanger because Freemen teaches that its heat exchanger structure provides the predictable advantage of “more opportunities for locating the heat exchanger in suitable places within the reactor vessel” due to its small size ([0058[).
Interviews
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
Additional References
The attached Notice of Reference Cited (PTO-892) cites additional prior art made of record and not relied upon that is considered pertinent to applicant's disclosure.
Finality
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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
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