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
A reply was filed on 10/20/2025. The amendments to the claims and specification have been entered. Claims 1, 4-8, and 10-21 are pending in the application with claims 5-8, 15-181, and 20-21 withdrawn. Claims 1, 4, 10-14, and 19 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.
Claim Rejections - 35 USC § 102
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by US Patent No. 5,087,412 (“Bingham”).
Regarding claim 1, Bingham (previously cited via PTO-892 dated 09/26/2023) (see FIGS. 1, 3, 4B-C) discloses an aft plenum assembly capable of being used with a nuclear thermal propulsion reactor (10) (1:6-8), the nuclear thermal propulsion reactor including a pressure vessel and a nozzle assembly at an end of the pressure vessel adjacent to the nozzle assembly, comprising:
a top plenum plate (32) defining a first plurality of fuel flow apertures (e.g., apertures through which elements 18, 36 extend) (3:6-9);
a bottom plenum plate (e.g., lower plate defining space 30) parallel to the top plenum plate thereby defining a plenum space (30) therebetween (2:59-61), the bottom plenum plate defining a second plurality of fuel flow apertures (e.g., apertures through which elements 18 extend) (3:6-9); and
a plurality of tubular connections (18) extending between the first plurality of fuel flow apertures of the top plenum plate and the second plurality of fuel flow apertures of the bottom plenum plate such that the tubular connections provide respective passages from the first plurality of fuel flow apertures of the top plenum plate to the second plurality of fuel flow apertures of the bottom plenum plate and the plenum space is between the tubular connections (2:59-61, 3:6-9),
wherein the top plenum plate defines a plurality of coolant flow apertures (34) in fluid communication with the plenum space between the top plenum plate and the bottom plenum plate (2:67-3:3).
Claim Rejections - 35 USC § 103
Claims 1 and 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over “Performance of HALEU and HEU-Fueled Nuclear Thermal Propulsion Reactors” (“Nelson”) in view of Bingham.
Regarding claims 1 and 11, Nelson (previously cited) (see FIGS. 1-2) discloses a nuclear thermal propulsion reactor (“NTP”) (p. 3: “The current NTP baseline design is a 540 MWth thermal-spectrum reactor”) comprising:
a reactor pressure vessel (“RV”, “Pressure Vessel”) defining an interior volume;
a nozzle assembly (“Chamber/Nozzle Throat”);
a reactor core (“Core Region”, “Core”) including a plurality of fuel assemblies (“Fuel Assemblies”, “FA”) and moderator assemblies (“Moderator Block”, “Moderator”), the reactor core being disposed within the interior volume of the reactor pressure vessel; and
an aft plenum assembly (“AFT Support Plate and Plena”) comprising a plenum plate (“AFT Support Plate”) disposed within the pressure vessel,
wherein the aft plenum assembly is disposed at one end of the pressure vessel so as to be adjacent to the nozzle assembly, and the reactor core is supported on the aft plenum assembly.
Nelson appears to be silent as to the specific structure of the plenum plate.
Bingham (see FIGS. 1, 3, 4B-C) is similarly directed towards a nuclear thermal propulsion reactor (1:6-8) comprising an aft plenum assembly comprising a plenum plate. Bingham teaches the plenum plate includes a top plenum plate (32) defining a first plurality of fuel flow apertures (e.g., apertures through which elements 18, 36 extend) (3:6-9); a bottom plenum plate (e.g., lower plate defining space 30) parallel to the top plenum plate thereby defining a plenum space (30) therebetween (2:59-61), the bottom plenum plate defining a second plurality of fuel flow apertures (e.g., apertures through which elements 18 extend) (3:6-9); and a plurality of tubular connections (18) extending between the first plurality of fuel flow apertures of the top plenum plate and the second plurality of fuel flow apertures of the bottom plenum plate such that the tubular connections provide respective passages from the first plurality of fuel flow apertures of the top plenum plate to the second plurality of fuel flow apertures of the bottom plenum plate and the plenum space is between the tubular connections (3:6-9), wherein the top plenum plate defines a plurality of coolant flow apertures (34) in fluid communication with the plenum space between the top plenum plate and the bottom plenum plate (2:67-3:3). Bingham further teaches the plenum assembly provides the advantages of positioning the fuel assemblies and directing and distributing coolant inside and around the fuel assemblies (2:64-3:9). It would have therefore been obvious to a person having ordinary skill in the art before the effective filing date (“POSA”) to use the plenum assembly taught by Bingham in Nelson’s reactor for the benefits thereof. Thus, modification of Nelson in order to provide fuel support and coolant distribution, as suggested by Bingham, would have been obvious to a POSA.
Regarding claim 12, Nelson in view of Bingham teaches the nuclear thermal propulsion reactor of claim 11. Nelson discloses the plenum space is in fluid communication with moderator assemblies disposed within the pressure vessel (FIG. 1, p. 3: “This coolant passes through the core twice before exit through the nozzle ... and is used to cool the components with lower permissible temperatures, including the moderator block, the SiC/SiC moderator insulator”).
Regarding claim 13, Nelson in view of Bingham teaches the nuclear thermal reactor of claim 12. Bingham teaches the top plenum plate defines a plurality of coolant flow apertures (34) therein (FIGS. 4B-C, 2:67-3:3). Thus, Nelson, modified to include the plenum plate assembly taught by Bingham, would have resulted in the features of claim 13.
Claims 4, 10, 14, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Nelson in view of Bingham further in view of US Publication No. 2015/0357059 (“Lin”).
Regarding claims 4 and 14, Nelson in view of Bingham teaches the aft plenum assembly of claim 1 and the nuclear thermal propulsion reactor of claim 11, but does not appear to teach a flow distribution ring as recited in claims 4 and 14.
Lin (previously cited) (see FIGS. 2-3) is similarly directed towards a nuclear reactor (200) comprising a reactor core (16) supported on a plenum assembly, the plenum assembly comprising a top plenum plate (2) and a bottom plenum plate (9) defining a plenum space therebetween ([0072]). Lin teaches the plenum assembly further comprises a flow distribution ring (8) having a cylindrical side wall, wherein the flow distribution ring extends between the top and the bottom plenum plates so that the cylindrical side wall encircles the plenum space. Lin further teaches the flow distribution ring provides the advantages of reducing pressure loss and improving the uniformity of coolant distribution ([0074]-[0075]). It would have therefore been obvious to a POSA to include the flow distribution ring taught by Lin in the modified Nelson’s aft plenum assembly for the benefits thereof. Thus, further modification of Nelson in order to enhance coolant flow distribution, as suggested by Lin, would have been obvious to a POSA.
Regarding claims 10 and 19, Nelson in view of Bingham teaches the aft plenum assembly of claim 1 and the nuclear thermal propulsion reactor of claim 11, but does not appear to teach a thermal shield as recited in claims 10 and 19.
Lin (see FIGS. 2-3) is similarly directed towards a nuclear reactor (200) comprising a reactor core (16) supported on a plenum assembly, the plenum assembly comprising a top plenum plate (2) and a bottom plenum plate (9) defining a plenum space therebetween ([0072]). Lin teaches the plenum assembly further comprises a thermal shield formed by a shield plate (7) disposed parallel to a bottom surface of the bottom plenum plate so that a gap is disposed therebetween ([0067], [0071]; Examiner notes, any physical structure, such as Lin’s plate 7 would have at least some shielding capabilities as all materials have a non-zero, positive neutron absorbing/scattering cross-section2). Lin further teaches the thermal shield prevents the formation of vortexes and further enhances coolant flow distribution ([0072]). It would have therefore been obvious to a POSA to include the thermal shield taught by Lin in the modified Nelson’s aft plenum assembly for the benefits thereof. Thus, further modification of Nelson in order to further enhance coolant flow distribution, as suggested by Lin, would have been obvious to a POSA.
Response to Arguments
Applicant’s amendments to the claims overcome the prior 35 U.S.C. 112(b) rejections.
Applicant’s arguments regarding the prior art rejections have been considered, but are directed towards newly added and/or amended claim language and are therefore addressed in the rejections above.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. Prosecution on the merits is closed. 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 extension fee 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 date of this final action.
RCE Eligibility
Since prosecution is closed, this application is now eligible for a request for continued examination (RCE) under 37 CFR 1.114. Filing an RCE helps to ensure entry of an amendment to the claims, specification, and/or drawings.
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 7:30AM-5:30PM ET. Supervisor Jack Keith (SPE) can be reached at (571) 272-6878.
/JINNEY KIL/Examiner, Art Unit 3646
1 As noted in the Non-Final Rejection dated 09/26/2023, claim 18 is directed towards nonelected Species C and is therefore 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.
2 https://periodictable.com/