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 .
Continued Examination
A request for continued examination (RCE) under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant’s RCE submission filed on 03/10/2026 has been entered.
Status of Claims
A reply was filed on 03/10/2026. The amendments to the claims have been entered. Claims 1-6, 11, and 29-38 are pending in the application with claims 5 and 32 withdrawn. Claims 1-4, 6, 11, 29-31, and 33-38 are examined herein.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Note on Claim Interpretation
The term “high-assay low-enriched uranium”, or “HALEU”, is a known term in the art. “By definition, HALEU is enriched between 5% and less than 20%”1. See also 17/399,859 Response to Arguments dated 07/12/2023, p. 14. The term is being interpreted in accordance with this definition.
Claim Rejections - 35 USC § 103
Claims 1-4, 6, 11, 29-31, 33-34, 36, and 38 are rejected under 35 U.S.C. 103 as being unpatentable over US Publication No. 2017/0263345 (“Venneri”) in view of “Low enriched nuclear thermal propulsion neutronic, thermal hydraulic, and system design space analysis” (“Krecicki”).
Regarding claim 1, Venneri (previously cited) (see FIGS. 3-5, 7) discloses a nuclear fission structure, comprising:
a moderator block (e.g., core block which includes moderating materials 630, 685, 830, 885) including a plurality of fuel assembly openings and a plurality of moderator block coolant channels (810) (FIG. 3 (annotated below), [0062], [0093]); and
a plurality of fuel assemblies (310) (FIGS. 3-4 (annotated below)),
wherein each fuel assembly of the plurality of fuel assemblies includes one or more CERMET fuel elements contained within a fuel assembly outer structure (330) ([0009], [0012], [0083], [0104]-[0105]),
wherein each CERMET fuel element of the one or more CERMET fuel elements includes:
a CERMET fuel meat having a composition including high-assay low-enriched uranium (HALEU) with a U-235 assay above 5 percent and below 20 percent ([0009], [0012], [0104]-[0105]); and
a plurality of tubular-shaped, fuel element coolant channels (410A-N) ([0091]) including a cladding (520) (FIGS. 4-5, 7, [0091]),
wherein each CERMET fuel element of the one or more CERMET fuel elements has an axial centerline defining a longitudinal axis of the CERMET fuel element (FIG. 5),
wherein, in each CERMET fuel element of the one or more CERMET fuel elements:
the plurality of fuel element coolant channels of each of the one or more CERMET fuel elements extend in a longitudinal direction relative to the longitudinal axis of the respective CERMET fuel element from a first end surface of the respective CERMET fuel element to a second end surface of the respective CERMET fuel element (FIG. 5, [0091], [0094]),
in a cross-section of each of the one or more CERMET fuel elements when viewed perpendicular to the longitudinal axis of the respective CERMET fuel element, the plurality of fuel element coolant channels are distributively arranged in the CERMET fuel meat (FIGS. 4, 7),
wherein each fuel assembly of the plurality of fuel assemblies is located in a different one of the plurality of fuel assembly openings (FIGS. 3-4 (annotated below)),
wherein, in a cross-section of the moderator block perpendicular to a longitudinal axis of the nuclear fission reactor structure, the plurality of fuel assemblies are distributively arranged in the moderator block (FIG. 3 (annotated below)),
wherein each moderator block coolant channel of the plurality of moderator block coolant channels extends in a longitudinal direction relative to the longitudinal axis of the nuclear fission reactor structure from a first end surface of the moderator block to a second end surface of the moderator block (FIG. 6), and
wherein the plurality of moderator block coolant channels are in spaced-apart relation to, and distributed about, a periphery of each of the plurality of fuel assembly openings (FIGS. 3-4 (annotated below)).
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Venneri does not appear to disclose the cladding has a composition including a tungsten-containing alloy. Krecicki (previously cited) is similarly directed towards a CERMET fuel element for a nuclear fission reactor structure and teaches the CERMET fuel element may comprise fuel element coolant channels (“fuel element flow channels”) including a cladding (“cladding”) having a composition including a tungsten-containing alloy (p. 3: “Dispersion strengthened alloys have been previously used as a cladding for the ANL-200 design, where the fuel element flow channels were cladded with a W-30Mo-30Re alloy”). It would have been obvious to a person having ordinary skill in the art before the effective filing date (“POSA”) to use a tungsten-containing alloy for the material of Venneri’s cladding, as taught by Krecicki, since 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. See In re Leshin, 125 USPQ 416.
Regarding claim 2, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the composition of the CERMET fuel meat includes uranium dioxide (UO2), rather than uranium nitride (UN) as recited in claim 2. However, Krecicki teaches the composition of the CERMET fuel meat may include UN (p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”). Krecicki further teaches UN fuel provides the advantages of high thermal conductivity and increased uranium loading density (p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”, “The thermal conductivities of UN and UO2 are presented..., which clearly shows the superior properties of UN, which are further enhanced with temperature, as opposed to UO2”, “In addition, one of the key advantages of UN is the increased uranium loading density, i.e., ~ 40% more than UO2”). It would have therefore been obvious to a POSA to use UN CERMET fuel meat, as taught by Krecicki, for the fuel performance benefits thereof. Thus, further modification of Venneri in order to enhance thermal conductivity and uranium loading density, as suggested by Krecicki, would have been obvious to a POSA.
Regarding claim 3, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the composition of the CERMET fuel meat includes W ([0104]).
Regarding claim 4, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the composition of the CERMET fuel meat includes uranium dioxide (UO2) and tungsten ([0104]-[0105]), rather than uranium nitride (UN), tungsten, and molybdenum as recited in claim 4. However, Krecicki teaches the composition of the CERMET fuel meat may include UN, tungsten, and molybdenum (p. 2: “The ANL NTP designs included W and Mo matrices with UO2 fuel embedded in the cermet fuel matrix. Molybdenum is an attractive alternative due to its reduced neutron absorption cross-section and comparable thermal conductivity”; p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”, “Recent research and development efforts and small business innovation research solicitations have focused on dispersion strengthened molybdenum/tungsten alloys.... Recent work done by NASA on LEU NTPs has utilized a Mo-30W alloy and the same alloy is adopted in the current study”). Krecicki further teaches UN fuel provides the advantages of high thermal conductivity and increased uranium loading density (p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”, “The thermal conductivities of UN and UO2 are presented..., which clearly shows the superior properties of UN, which are further enhanced with temperature, as opposed to UO2”, “In addition, one of the key advantages of UN is the increased uranium loading density, i.e., ~ 40% more than UO2”), molybdenum has a low neutron absorption cross section (p. 2: “Molybdenum is an attractive alternative due to its reduced neutron absorption cross-section and comparable thermal conductivity”), and molybdenum tungsten alloys exhibit greater strength (p. 3: “Recent research and development efforts and small business innovation research solicitations have focused on dispersion strengthened molybdenum/tungsten alloys”). It would have therefore been obvious to a POSA to use a UN, tungsten, molybdenum CERMET fuel meat, as taught by Krecicki, for the fuel performance benefits thereof. Thus, further modification of Venneri in order to enhance thermal conductivity, uranium loading density, and strength and reduce neutron absorption, as suggested by Krecicki, would have been obvious to a POSA.
Regarding claim 6, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Krecicki teaches the tungsten-containing alloy is a Mo-W alloy containing 25 wt% to 50 wt% tungsten (p. 3: “the fuel element flow channels were cladded with a W-30Mo-30Re alloy”). Thus, Venneri, modified to include the tungsten-containing alloy cladding as taught by Krecicki, would have resulted in the features of claim 6.
Regarding claim 11, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the moderator block has a composition including zirconium hydride (ZrH) and graphite ([0092]-[0093])
Regarding claim 33, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Krecicki teaches the tungsten-containing alloy is a Mo-W alloy containing 30 wt% to 40 wt% tungsten (p. 3: “the fuel element flow channels were cladded with a W-30Mo-30Re alloy”). Thus, Venneri, modified to include the tungsten-containing alloy cladding as taught by Krecicki, would have resulted in the features of claim 33.
Regarding claim 34, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Krecicki teaches another tungsten-containing alloy suitable for the cladding, the tungsten-containing alloy being a Mo-W alloy containing 30 wt% to 36 wt% tungsten (p. 3: “a Mo-30 W alloy”). It would have been obvious to a POSA to use Krecicki’s Mo-30W alloy for the material of the cladding because Krecicki teaches it is a suitable alternative to the W-30Mo-30Re alloy and since 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. See In re Leshin, 125 USPQ 416.
Regarding claim 36, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri disclose each fuel assembly of the plurality of fuel assemblies further includes an insulation layer (520) interposed between an inner surface of the fuel assembly outer structure and an outer surface of the one or more CERMET fuel elements (FIGS. 3, 5, [0091], [0094]).
Regarding claim 38, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri discloses each fuel assembly of the plurality of fuel assemblies has an axial centerline defining a longitudinal axis of the fuel assembly, and wherein, in each fuel assembly of the plurality of fuel assemblies, the CERMET fuel meat and the plurality of fuel element coolant channels are axisymmetric about the longitudinal axis of the fuel assembly (FIGS. 5, 7).
Regarding claim 29, Venneri discloses a nuclear propulsion fission reactor structure, comprising:
a nuclear fission reactor structure (FIG. 3).
an inlet connection assembly (e.g., space above core 110) (FIGS. 1-2); and
an outlet connection assembly (e.g., space below core 110) (FIGS. 1-2),
wherein the inlet connection assembly includes an inlet plenum connecting entrance openings of the plurality of fuel assemblies (FIGS. 1-2), and
wherein the outlet connection assembly includes an outlet plenum connecting exit openings of the plurality of fuel assemblies (FIGS. 1-2).
Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1 as discussed above. Thus, Venneri’s nuclear propulsion fission reactor structure, modified to include the tungsten-containing alloy cladding as taught by Krecicki, would have resulted in the features of claim 29.
Regarding claim 30, Venneri discloses a nuclear thermal propulsion engine, comprising (FIGS. 1-2):
a nuclear propulsion fission reactor structure;
shielding (150, 160);
turbomachinery (140); and
a nozzle (170),
wherein, in a flow path of the propulsion gas, the shielding and the turbomachinery are operatively mounted upstream of the inlet connection assembly, and wherein, in the flow path of the propulsion gas, the nozzle is operatively mounted downstream of the outlet connection assembly.
Venneri in view of Krecicki teaches the nuclear propulsion fission reactor structure according to claim 29 as discussed above. Thus, Venneri’s nuclear propulsion fission reactor structure, modified to include the tungsten-containing alloy cladding as taught by Krecicki, would have resulted in the features of claim 30.
Regarding claim 31, Venneri in view of Krecicki teaches the nuclear thermal propulsion engine according to claim 30. Venneri discloses the nozzle provides a flow path for superheated propulsion gas exiting the nuclear propulsion fission reactor structure ([0060], [0065]).
Claim 35 is rejected under 35 U.S.C. 103 as being unpatentable over Venneri in view of Krecicki further in view of US Publication No. 2016/0049210 (“Filippone”).
Regarding claim 35, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri appears to be silent as to the composition of the fuel assembly outer structure. Filippone (newly cited) (see FIG. 1) is similarly directed towards a nuclear fission reactor structure comprising a fuel assembly outer structure (209, 311) which contains fuel elements (203) and defines a pressure vessel ([0060]). Filippone teaches the fuel assembly outer structure may include a refractory carbide (e.g., SiC) ([0063]; see also instant specification [0037]). Filippone further teaches the silicon carbide is a light weight material suitable for providing a pressure boundary ([0063]). It would have therefore been obvious to a POSA to have the modified Venneri’s fuel assembly outer structure include a refractory carbide, as taught by Filippone, for the benefits thereof. Thus, further modification to reduce the weight of Venneri’s nuclear fission reactor structure, as suggested by Filippone, would have been obvious to a POSA. Additionally, it would have been obvious to a POSA to have the composition of the fuel assembly outer structure include a refractory carbide since 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. See In re Leshin, 125 USPQ 416.
Claim Rejections - 35 USC § 103
Alternatively, in the event claim 1 is intending to require each of the fuel assemblies includes a separate fuel assembly outer structure (e.g., “wherein each fuel assembly of the plurality of fuel assemblies includes one or more CERMET fuel elements and a fuel assembly outer structure”), the following rejections are made. Examiner notes, claims 35-36 recite a singular “the fuel assembly outer structure” which would appear to be inconsistent with each fuel assembly including a separate fuel assembly outer structure.
Claims 1-4, 6, 11, 29-31, 33-35, and 38 are rejected under 35 U.S.C. 103 as being unpatentable over Venneri in view of Krecicki.
Regarding claim 1, Venneri (see FIGS. 3-5, 7) discloses a nuclear fission structure, comprising:
a moderator block (e.g., core block which includes moderating materials 630, 685, 830, 885) including a plurality of fuel assembly openings and a plurality of moderator block coolant channels (810) (FIG. 3 (annotated above), [0062], [0093]); and
a plurality of fuel assemblies (310) (FIGS. 3-4 (annotated above)),
wherein each fuel assembly of the plurality of fuel assemblies includes one or more CERMET fuel elements contained within a fuel assembly outer structure (520) ([0009], [0012], [0091], [0094], [0104]-[0105]),
wherein each CERMET fuel element of the one or more CERMET fuel elements includes:
a CERMET fuel meat having a composition including high-assay low-enriched uranium (HALEU) with a U-235 assay above 5 percent and below 20 percent ([0009], [0012], [0104]-[0105]); and
a plurality of tubular-shaped, fuel element coolant channels (410A-N) ([0091]) including a cladding (520) (FIGS. 4-5, 7, [0091]),
wherein each CERMET fuel element of the one or more CERMET fuel elements has an axial centerline defining a longitudinal axis of the CERMET fuel element (FIG. 5),
wherein, in each CERMET fuel element of the one or more CERMET fuel elements:
the plurality of fuel element coolant channels of each of the one or more CERMET fuel elements extend in a longitudinal direction relative to the longitudinal axis of the respective CERMET fuel element from a first end surface of the respective CERMET fuel element to a second end surface of the respective CERMET fuel element (FIG. 5, [0091], [0094]),
in a cross-section of each of the one or more CERMET fuel elements when viewed perpendicular to the longitudinal axis of the respective CERMET fuel element, the plurality of fuel element coolant channels are distributively arranged in the CERMET fuel meat (FIGS. 4, 7),
wherein each fuel assembly of the plurality of fuel assemblies is located in a different one of the plurality of fuel assembly openings (FIGS. 3-4 (annotated below)),
wherein, in a cross-section of the moderator block perpendicular to a longitudinal axis of the nuclear fission reactor structure, the plurality of fuel assemblies are distributively arranged in the moderator block (FIG. 3 (annotated below)),
wherein each moderator block coolant channel of the plurality of moderator block coolant channels extends in a longitudinal direction relative to the longitudinal axis of the nuclear fission reactor structure from a first end surface of the moderator block to a second end surface of the moderator block (FIG. 6), and
wherein the plurality of moderator block coolant channels are in spaced-apart relation to, and distributed about, a periphery of each of the plurality of fuel assembly openings (FIGS. 3-4 (annotated below)).
Venneri does not appear to disclose the cladding has a composition including a tungsten-containing alloy. Krecicki (previously cited) is similarly directed towards a CERMET fuel element for a nuclear fission reactor structure and teaches the CERMET fuel element may comprise fuel element coolant channels (“fuel element flow channels”) including a cladding (“cladding”) having a composition including a tungsten-containing alloy (p. 3: “Dispersion strengthened alloys have been previously used as a cladding for the ANL-200 design, where the fuel element flow channels were cladded with a W-30Mo-30Re alloy”). It would have been obvious to a POSA to use a tungsten-containing alloy for the material of Venneri’s cladding, as taught by Krecicki, since 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. See In re Leshin, 125 USPQ 416.
Regarding claims 2-4, 6, 11, 29-31, 33-34, and 38, Venneri in view of Krecicki teaches the features of these claims as discussed in the above rejections and incorporated herein.
Regarding claim 35, Venneri in view of Krecicki teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the fuel assembly outer structure has a composition including a refractory carbide (e.g., ZrC)2 ([0092], [0094]).
Claims 1-4, 6, 11, 29-31, and 33-38 are rejected under 35 U.S.C. 103 as being unpatentable over Venneri in view of Krecicki and “Innovative Concept for an Ultra-Small Nuclear Thermal Rocket Utilizing a New Moderated Reactor” (“Nam”).
Alternatively, regarding claim 1, Nam (cited via Applicant-submitted IDS dated 09/25/2024) (see FIGS. 2-3) is similarly directed towards a nuclear fission structure comprising a plurality of fuel assemblies (“fuel assembly”) wherein each fuel assembly of the plurality of fuel assemblies includes one or more CERMET fuel elements (“fuel”) (Table 2, Abstract). Nam teaches the one or more CERMET fuel elements are contained within a fuel assembly outer structure (“tubes”, “C/C shroud”) (p. 683: “The fuel assembly is supported and surrounded by three layer tubes...: first, a carbon fiber-reinforced carbon (C/C) shroud protectively coated with zirconium carbide (ZrC)”). Nam further teaches the fuel assembly outer structure provides the advantages of supporting the fuel assembly while providing heat and corrosion resistance and insulation from the propellant (p. 683: “The first ZrC-coated C/C shroud is highly heat and corrosion resistant in order to directly support the fuel assembly and to insulate the very high temperature H2”). It would have therefore been obvious to a POSA to include an outer structure as taught by Nam in the modified Venneri’s nuclear fission reactor structure for the benefits thereof. Thus, further modification of Venneri in order to enhance support, insulation, and heat and corrosion resistance, as suggested by Nam, would have been obvious to a POSA.
Regarding claim 2, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the composition of the CERMET fuel meat includes uranium dioxide (UO2), rather than uranium nitride (UN) as recited in claim 2. However, Krecicki teaches the composition of the CERMET fuel meat may include UN (p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”). Krecicki further teaches UN fuel provides the advantages of high thermal conductivity and increased uranium loading density (p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”, “The thermal conductivities of UN and UO2 are presented..., which clearly shows the superior properties of UN, which are further enhanced with temperature, as opposed to UO2”, “In addition, one of the key advantages of UN is the increased uranium loading density, i.e., ~ 40% more than UO2”). It would have therefore been obvious to a POSA to use UN CERMET fuel meat, as taught by Krecicki, for the fuel performance benefits thereof. Thus, further modification of Venneri in order to enhance thermal conductivity and uranium loading density, as suggested by Krecicki, would have been obvious to a POSA.
Regarding claim 3, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the composition of the CERMET fuel meat includes W ([0104]).
Regarding claim 4, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the composition of the CERMET fuel meat includes uranium dioxide (UO2) and tungsten ([0104]-[0105]), rather than uranium nitride (UN), tungsten, and molybdenum as recited in claim 4. However, Krecicki teaches the composition of the CERMET fuel meat may include UN, tungsten, and molybdenum (p. 2: “The ANL NTP designs included W and Mo matrices with UO2 fuel embedded in the cermet fuel matrix. Molybdenum is an attractive alternative due to its reduced neutron absorption cross-section and comparable thermal conductivity”; p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”, “Recent research and development efforts and small business innovation research solicitations have focused on dispersion strengthened molybdenum/tungsten alloys.... Recent work done by NASA on LEU NTPs has utilized a Mo-30W alloy and the same alloy is adopted in the current study”). Krecicki further teaches UN fuel provides the advantages of high thermal conductivity and increased uranium loading density (p. 3: “the UO2 fuel kernel could be replaced with high-temperature and high-conductive fuel alternatives such as uranium nitride (UN) cermet fuels”, “The thermal conductivities of UN and UO2 are presented..., which clearly shows the superior properties of UN, which are further enhanced with temperature, as opposed to UO2”, “In addition, one of the key advantages of UN is the increased uranium loading density, i.e., ~ 40% more than UO2”), molybdenum has a low neutron absorption cross section (p. 2: “Molybdenum is an attractive alternative due to its reduced neutron absorption cross-section and comparable thermal conductivity”), and molybdenum tungsten alloys exhibit greater strength (p. 3: “Recent research and development efforts and small business innovation research solicitations have focused on dispersion strengthened molybdenum/tungsten alloys”). It would have therefore been obvious to a POSA to use UN, tungsten, molybdenum CERMET fuel meat, as taught by Krecicki, for the fuel performance benefits thereof. Thus, further modification of Venneri in order to enhance thermal conductivity, uranium loading density, and strength and reduce neutron absorption, as suggested by Krecicki, would have been obvious to a POSA.
Regarding claim 6, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Krecicki teaches the tungsten-containing alloy is a Mo-W alloy containing 25 wt% to 50 wt% tungsten (p. 3: “the fuel element flow channels were cladded with a W-30Mo-30Re alloy”). Thus, Venneri, modified to include the tungsten-containing alloy cladding as taught by Krecicki and the fuel assembly outer structure as taught by Nam, would have resulted in the features of claim 6.
Regarding claim 11, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Venneri discloses the moderator block has a composition including zirconium hydride (ZrH) and graphite ([0092]-[0093])
Regarding claim 33, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Krecicki teaches the tungsten-containing alloy is a Mo-W alloy containing 30 wt% to 40 wt% tungsten (p. 3: “the fuel element flow channels were cladded with a W-30Mo-30Re alloy”). Thus, Venneri, modified to include the tungsten-containing alloy cladding as taught by Krecicki and the fuel assembly outer structure as taught by Nam, would have resulted in the features of claim 33.
Regarding claim 34, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Krecicki teaches another tungsten-containing alloy suitable for the cladding, the tungsten-containing alloy being a Mo-W alloy containing 30 wt% to 36 wt% tungsten (p. 3: “a Mo-30 W alloy”). It would have been obvious to a POSA to use Krecicki’s Mo-30W alloy for the material of the cladding because Krecicki teaches it is a suitable alternative to the W-30Mo-30Re alloy and since 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. See In re Leshin, 125 USPQ 416.
Regarding claim 35, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Nam teaches the fuel assembly outer structure has a composition including a refractory carbide (e.g., ZrC)3 (p. 683: “a carbon fiber-reinforced carbon (C/C) shroud protectively coated with zirconium carbide (ZrC)”). Thus, Venneri, modified to include the tungsten-containing alloy cladding as taught by Krecicki and the fuel assembly outer structure as taught by Nam, would have resulted in the features of claim 35.
Regarding claim 36, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Nam teaches each fuel assembly of the plurality of fuel assemblies further includes an insulation layer (“annular moderator cooling channel”) interposed between an inner surface of the fuel assembly outer structure and an outer surface of the one or more CERMET fuel elements (FIG. 3, p. 683: “there is an annular moderator cooling channel between the first C/C shroud and the C/C jacket of the hydride moderator to insulate the high thermal energy conducted from the fuel assembly, to cool the moderator, and to transfer the thermal energy to the PFS [propellant feeding system] and EGS [electricity generation system]”). Nam further teaches the insulation layer provides the advantages of insulating and transferring thermal energy from the fuel assembly (p. 683: “there is an annular moderator cooling channel between the first C/C shroud and the C/C jacket of the hydride moderator to insulate the high thermal energy conducted from the fuel assembly, to cool the moderator, and to transfer the thermal energy to the PFS [propellant feeding system] and EGS [electricity generation system]”). It would have therefore been obvious to a POSA to include the insulation layer as taught by Nam in the modified Venneri’s nuclear fission reactor structure for the insulation and heat transfer benefits thereof, as suggested by Nam.
Regarding claim 37, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 36. Nam teaches an inner surface of the insulation layer is spaced apart from the outer surface of the one or more CERMET fuel elements to form a gap (e.g., occupied by the “third C/C pressure tube”) (FIG. 3). Thus, Venneri, modified to include the tungsten-containing alloy cladding as taught by Krecicki and the fuel assembly outer structure and insulation layer as taught by Nam, would have resulted in the features of claim 37.
Regarding claim 38, Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1. Venneri discloses each fuel assembly of the plurality of fuel assemblies has an axial centerline defining a longitudinal axis of the fuel assembly, and wherein, in each fuel assembly of the plurality of fuel assemblies, the CERMET fuel meat and the plurality of fuel element coolant channels are axisymmetric about the longitudinal axis of the fuel assembly (FIGS. 3, 5).
Regarding claim 29, Venneri discloses a nuclear propulsion fission reactor structure, comprising:
a nuclear fission reactor structure (FIG. 3).
an inlet connection assembly (e.g., space above core 110) (FIGS. 1-2); and
an outlet connection assembly (e.g., space below core 110) (FIGS. 1-2),
wherein the inlet connection assembly includes an inlet plenum connecting entrance openings of the plurality of fuel assemblies (FIGS. 1-2), and
wherein the outlet connection assembly includes an outlet plenum connecting exit openings of the plurality of fuel assemblies (FIGS. 1-2).
Venneri in view of Krecicki and Nam teaches the nuclear fission reactor structure according to claim 1 as discussed above. Thus, Venneri’s nuclear propulsion fission reactor structure, modified to include the tungsten-containing alloy cladding as taught by Krecicki and the fuel assembly outer structure as taught by Nam, would have resulted in the features of claim 29.
Regarding claim 30, Venneri discloses a nuclear thermal propulsion engine, comprising (FIGS. 1-2):
a nuclear propulsion fission reactor structure;
shielding (150, 160);
turbomachinery (140); and
a nozzle (170),
wherein, in a flow path of the propulsion gas, the shielding and the turbomachinery are operatively mounted upstream of the inlet connection assembly, and wherein, in the flow path of the propulsion gas, the nozzle is operatively mounted downstream of the outlet connection assembly.
Venneri in view of Krecicki and Nam teaches the nuclear propulsion fission reactor structure according to claim 29 as discussed above. Thus, Venneri’s nuclear propulsion fission reactor structure, modified to include the tungsten-containing alloy cladding as taught by Krecicki and the fuel assembly outer structure as taught by Nam, would have resulted in the features of claim 30.
Regarding claim 31, Venneri in view of Krecicki and Nam teaches the nuclear thermal propulsion engine according to claim 30. Venneri discloses the nozzle provides a flow path for superheated propulsion gas exiting the nuclear propulsion fission reactor structure ([0060], [0065]).
Response to Arguments
Applicant’s amendments to the claims overcome the prior drawing objections, claim objections, and 35 U.S.C. 112(b) rejections.
Applicant’s arguments regarding the prior art rejections have been fully considered, but are directed towards newly added and/or amended claim language and are therefore addressed in the above rejections.
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).
Interview Information
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.
Contact Information
Examiner Jinney Kil can be reached at (571) 272-3191, on Monday-Thursday from 8:30AM-6:30PM ET. Supervisor Jack Keith (SPE) can be reached at (571) 272-6878.
/JINNEY KIL/Examiner, Art Unit 3646
1 https://www.energy.gov/ne/articles/what-high-assay-low-enriched-uranium-haleu
2 https://en.wikipedia.org/wiki/Refractory_metals
3 https://en.wikipedia.org/wiki/Refractory_metals
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