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 .
Status of Claims
1. This office action is responsive to the IDS dated 04/07/26. This IDS postdates counting of the notice of allowance mailed 04/15/26. As such, the under examination presently are the claims presented in the notice of allowance. This office action is therefore directed to claims 1-4 in the amendments dated 01/23/26 and claims 5 and 6 as amended in the notice of allowance of 04/15/26.
2. Claims 1-6 are pending and examined herein.
Claim Objections
3. Claim 3 is objected to because of the following informalities: reactor is misspelled. Appropriate correction is required.
Claim Rejections - 35 USC § 103
4. 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.
5. 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.
6. 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.
7. Claims 1 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Kawashima et al., US 4,655,989 in view of Hitachi JP 63-6496 (cited on the IDS dated 04/06/26).
8. Regarding claim 1, Kawashima discloses a fast reactor (column 1, lines 5-8) core (Figs. 3, 5, 6) comprising:
first fuel assemblies (25B); and
second fuel assemblies (25A) different from the first fuel assemblies,
wherein the reactor core has an axial direction and a radial direction, and is axially heterogeneous (Fig. 5 and column 4, lines 49-50),
the reactor core further comprising:
an internal blanket region fuel (51) disposed at an axially middle section of the core,
an inner core fuel region (I) extending radially around a center of the reactor core, and
an outer core fuel region (II) disposed radially outside of the inner core region and extending radially toward a periphery of the reactor core (see Fig. 5),
wherein the first fuel assemblies are disposed in the outer core fuel region, and
the second fuel assemblies are disposed in the inner core fuel region (column 5, lines 7-51), and
wherein the internal blanket region is formed by an internal blanket section (36) in each of the first fuel assemblies and an internal blanket section (33) in each of the second fuel assemblies.
Kawashima does not disclose depleted uranium in its internal blanket region nor a thicker internal blanket in the outer core fuel region. Hitachi teaches a fast reactor core (Fig. 1, p. 1) comprising
an internal blanket region containing depleted uranium fuel (p. 4: “The core in question is loaded with a core fuel consisting of a mixed oxide of plutonium and uranium, and a blanket fuel consisting mainly of depleted uranium, using sodium as coolant.”)
wherein a thickness in the axial direction of the internal blanket section in each of the first fuel assemblies is thicker than a thickness in the axial direction of the internal blanket section in each of the second fuel assemblies in the axial direction of the reactor core (see Fig. 1).
One of ordinary skill in the art at the time of invention/filing would have found it obvious to apply the internal blanket taught by Hitachi to the reactor of Kawashima because Hitachi teaches that such an internal blanket has a high neutron absorption effect, which reduces maximum fast neutron flux, and extends fuel life (p. 4).
9. Regarding claim 3, Kawashima as modified by Hitachi makes claim 1 obvious. Kawashima further discloses a sodium cooled fast reactor core (see column 7, lines 55-65).
10. Claims 2 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Kawashima et al., US 4,655,989 in view of Hitachi JP 63-6496 (cited on the IDS dated 04/06/26) in further view of Fujimura, JP 2016/085118.
11. Regarding claim 2, Kawashima as modified by Hitachi makes claim 1 obvious. Kawashima further discloses a fast reactor core wherein each of the first fuel assemblies and the second fuel assemblies further comprise a core fuel section containing Pu (column 5, lines 27-29; see also Figs. 7A and 7B 32A, 32B, 35A, 35B), and suggests placing higher Pu enrichment fuel in the outer core fuel region (see column 11, lines 20-22). However, Kawashima is silent as to the relative Pu enrichment of the fuel assemblies in the core of Figs. 3-6. Fujimura teaches a fast reactor core (see Fig. 2) wherein a Pu enrichment of the core fuel section in each of the first fuel assemblies is higher than a Pu enrichment of the core fuel section in each of the second fuel assemblies (see p. 4 of the attached translation). One of ordinary skill in the art at the time of invention/filing would have found it obvious to apply the Pu enrichment taught by Fujimura to the reactor core of Kawashima because Fujimura states that such a Pu enrichment arrangement predictably provides “power in the radial direction of the core is flattened” (p. 4).
12. Regarding claim 5, Kawashima as modified by Hitachi and Fujimura makes claim 1 obvious. Fujimura is silent as to the absolute value of the Pu enrichment of its outer and inner core region fuels. However, such a value is a result-effective variable, because the overall Pu enrichment of the core will determine its neutronic properties and its power output, while the placement of the Pu fuel will dictate the core’s neutron flux map. Accordingly, one of ordinary skill in the art at the time of invention/filing would have found it obvious to determine the optimum values for the Pu enrichment of the core fuel regions to achieve a desired neutron flux map and power output in the application of Fujimura’s teaching to Kawashima’s core. See MPEP 2144.05(II).
13. Regarding claim 6, Kawashima as modified by Hitachi and Fujimura makes claim 1 obvious. Kawashima further discloses a fast reactor core wherein a sodium plenum region is disposed in the axial direction above the inner core fuel region and the outer core fuel region in a top part of the fast reactor core (see Fig. 3) and wherein MOX fuel pellets are disposed in the core fuel sections in each of the first fuel assemblies and the core fuel sections in each of the second fuel assemblies (column 5, line 29). Hitachi further teaches depleted uranium oxide pellets are disposed in the internal blanket section of each of the first fuel assemblies and in the internal blanket section of each of the second fuel assemblies; and an axial midplane of the internal blanket region is positioned below an axial midplane of the fast reactor core (see Fig. 1 and p. 4). One of ordinary skill in the art at the time of invention/filing would have found it obvious to apply the internal blanket taught by Hitachi to the reactor of Kawashima for the reason stated above.
14. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Kawashima et al., US 4,655,989 in view of Hitachi JP 63-6496 (cited on the IDS dated 04/06/26) in further view of Fujimura, JP 2016/085118, in further view of Fujimura et al., US 2019/0392957 (hereinafter Fujimura ‘957).
15. Regarding claim 4, Kawashima as modified by Hitachi and Fujimura makes claim 1 obvious. Kawashima does not discloses metallic fuel. Fujimura ‘957 teaches a fast reactor core (Abs.) wherein
wherein the core fuel sections of the first fuel assemblies and the core fuel sections of the second fuel assemblies comprise a metallic U-Pu-Zr alloy fuel, and wherein the internal blanket section in each of the first fuel assemblies and the internal blanket section in each of the second fuel assemblies comprise a metallic fuel of a U-Zr alloy fuel ([0048]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to substitute the metallic fuel taught by Fujimura ‘957 to the reactor core of Kawashima to improve heat transfer and economic efficiency (see [0005]).
Finality
Applicant's submission of an information disclosure statement under 37 CFR 1.97(c) with the timing fee set forth in 37 CFR 1.17(p) on 04/07/26 prompted the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 609.04(b). 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.
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/SHARON M DAVIS/Primary Examiner, Art Unit 3646
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