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 .
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.
Amendments
Applicant’s amendments to the specification and claims 1, 14-16, and 20 are acknowledged and accepted. The prior claim objections and rejections under 35 USC § 112(b) are withdrawn.
Specification
The disclosure is objected to because of the following informalities:
Paragraphs [0031] and [0038], in the original as-filed specification, should be amended to use proper subscripts in the chemical formulas recited therein.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
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.
Claims 1-15 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.
The term “substantially defluorinated” in claim 1 is a relative term which renders the claim indefinite. The term “substantially defluorinated” 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. It is therefore unclear what level of defluorination is required to meet the claim limitation of being “substantially defluorinated with requiring treatment in a secondary reactor.” For the purposes of further examination, any defluorination greater than 95% shall be considered “substantial.”
Claims 2-15 depend upon claim 1 without resolving the indefiniteness associated with the required degree of defluorination.
Claim Rejections - 35 USC § 103
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-9 and 16-21 are rejected under 35 U.S.C. 103 as being unpatentable over Urza (US 4,830,841 A) in view of Kimura et al. (US 2011/0110837 A1) and Seider et al. (Product and Process Design Principles - Synthesis, Analysis, and Evaluation (4th Edition), Chapter 22. Optimal Design and Scheduling of Batch Processes. New York: John Wiley & Sons, Inc. 2017).
Regarding claim 1, Urza teaches a process for conversion of UF6 to produce UO2 feed for nuclear fuel (ceramic grade uranium oxide; abstract), comprising the following steps:
providing a seed bed of uranium dioxide (UO2) powder in a fluidized bed reactor vessel (uranium oxide material approximating UO2 was charged into the fluidized bed section of the reactor to establish the initial bed of fluidized solids; col. 5, lines 12-16);
fluidizing the UO2 powder in the reactor vessel using an upflow stream comprising an inert gas (nitrogen), while heating the reactor vessel, and feeding a stream of hydrogen and steam to the upflow stream of inert gas (the fluidized bed section and the reaction zone of the vessel were maintained at 650 °C and 500 °C …a preheated mixture of nitrogen, hydrogen, and steam was used to fluidize the bed; col. 5, lines 16-20; Fig. 1 shows it is in an upflow reactor);
feeding vaporized uranium hexafluoride (UF6) and additional steam to the fluidized bed reactor vessel (uranium hexafluoride was fed into the reaction zone with preheated steam; col. 5, lines 20-21)
reacting the UF6 with some of the steam to yield uranyl fluoride (UO2F2) (uranyl fluoride formed; col. 5, line 34; conversion of uranium hexafluoride with superheated steam …to produce submicron Uranyl fluoride; col. 1, lines 59-61);
reacting the UO2F2 with the hydrogen in the upflow stream to yield additional UO2 powder (the product was granular, free flowing …the composition of the fluoride containing uranium oxide was 87.1 weight percent uranium and 0.24 weight percent fluoride, which shows that most of the UO2F2 (77.3% U, 12.3% F) is converted to UO2 (88.1% U,0 0% F); col. 5, lines 39-42; Eq. 2 shows this is by reaction with hydrogen) which accumulates in the fluidized bed (product [UO2] from the reactor was routinely withdrawn to maintain a constant bed level; col. 5, lines 17-18); and,
stopping the feeding of UF6 and allowing any residual UF6 in the reactor vessel to react with the stream of hydrogen and steam to yield additional UO2 powder which accumulates in the fluidized bed (after the flow UF6 was terminated, the bed material was retained in the fluidized bed for 30 min for further defluorination; col. 5, line 43-44), wherein the UO2 powder in the fluidized bed is substantially defluorinated without requiring treatment in a secondary reactor (the fluoride level of the retained uranium oxide bed material was reduced to 50 ppm; col. 5, lines 45-46).
Because the UF6 was introduced together with additional steam (uranium hexafluoride was fed into the reaction zone with preheated steam; col. 5, lines 20-21) through a single concentric nozzle (col. 2, lines 26-28), terminating the UF6 stream is interpreted as also terminating the additional steam. Even if this were not the case, it would have been obvious to one of ordinary skill in the art to also terminate the additional steam because the reduction reaction with hydrogen is occurring in the fluidized bed and there is already steam being provided to this bed via line 16 (col. 2, lines 28-32) and steam entering above the bed via lines 13 and 14 (col. 2, lines 27-28 and Figure) would not be required.
Regarding the limitation where the stream of hydrogen and steam are stopped to enable discharge of a quantity of the UO2 powder from the reactor vessel, it is noted that it would be obvious to at some point shut down the reactor of Urza and to remove the products, thereby meeting this claim limitation.
Urza does not teach the UO2 powder or the UF6 comprising uranium with greater than 5% by weight U-235 isotope, making them HALEU materials, nor does Uraz teach the process being a semi-batch process where the UF6 and additional steam feed is stopped when the UO2 in the fluidized bed reaches a target accumulated mass, or the seed bed having a mass that is between 5% and 20% of the target accumulated mass.
However, Kimura teaches a reactor for conversion of UF6 to UO2 (title) and further teaches that their reactor can be used for the specific operations outlined by Urza (US Pat. 4,830,841) on U-235 enriched materials ([0026]). Kimura further teaches that these materials can be 6.0%, 7.0% and up to 100% enriched in U-235 (Table between [0029] and [0030]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the method of Urza for enriched UF6 (fluorinated HALEU material) and enriched UO2 to produce a HALEU feed, where the weight percent of uranium U-235 in the uranium of UF6 and UO2 is 6.0%, which falls in the instantly claimed range. One of ordinary skill in the art would have been motivated to do so because Kimura teaches that their modification allowing use of Urza’s method on higher % U-235 represents an improvement on the method of Urza ([0024]).
Regarding the limitation where the process is a semi-batch process, Seider teaches that it is often desirable to use batch or semi-batch (semicontinuous) processes where reactant feed is stopped and product is discharged (Figure 22.1) when the chemicals are hazardous or toxic or when safety aspects are of great concern (Section 22.1, ¶ 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adapt the method of Urza to a semi-batch process. One of ordinary skill in the art would have been motivated to do so because safety aspects are of great concern with enriched uranium and Seider teaches that when that is the case one may want to opt for a semi-batch process instead of a continuous one.
Regarding the limitation where the UF6 and additional steam feed is stopped when the UO2 in the fluidized bed reaches a target accumulated mass, because Urza teaches that the UF6 and steam feed is stopped to allow for a 30 min period where reduction is allowed to occur (after the flow of UF6 was terminated, the bed material was retained in the fluidized bed for 30 minutes for further defluorination and reduction; col. 5, lines 42-45), it would have been obvious in a semi-batch process to base the time at which this termination occurred on some process parameter linked to reaction progress, and therefore also related to the amount of UO2 accumulated in the fluidized bed. One of ordinary skill in the art would have been motivated to base the point on which the feed of UF6 and additional steam is stopped on some process parameter, and therefore also on the amount of UO2 in the fluidized bed, in order to optimize batch time, as taught by Seider (Section 22.2) and also to avoid overfilling of the reactor with accumulated product.
Regarding the limitation of the seed bed having a mass that is between 5% and 20% of the target accumulated mass, because Seider teaches optimizing batch time and therefore target accumulated mass, they also teach optimizing the ratio of the seed bed mass to the target accumulated mass. The courts have also found that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed range for the mass of the seed bed merely represents an obvious variant and/or routine optimization of the seed bed used in the cited prior art.
Regarding claim 2, modified Urza teaches the process of claim 1, where Urza also teaches discharging enough of the UO2 powder from the reactor vessel to leave behind a bed of UO2 powder (product from the reactor was routinely withdrawn to maintain a constant bed level; col. 5, lines37-38) as well as reusing the uranium dioxide from a previous run (col. 2, line 34), which implies a second run of the process can be performed; such a repeat run would entail repeating steps b to h.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to discharge enough of the UO2 powder from the reactor vessel to leave behind a seed bed of UO2 powder and repeating steps b) to h), as taught by Urza. One of ordinary skill in the art would have been motivated to do so because this would simplify the procedure and not require discharging all the UO2 only to reload it for use in the next run.
Regarding claims 3 and 4, modified Urza teaches the method of claim 1, but does not teach the target mass being at least about three or five times a mass of the seed bed, as required by claims 3 and 4.
However, Seider teaches that in semi-batch processes it is desired to optimize the batch time, or how long a reaction proceeds per batch (Section 22.2), which will be directly related to the amount of UO2 product produced before the reactant feed is stopped. Seider further teaches in Example 22.2 that such optimization can be applied to a batch process where a feed is stopped and a reaction continues. Though Seider’s Example 22.2 is directed at the biosynthesis of penicillin and not production of UO2, one of ordinary skill in the art would find the general teachings of Seider for optimization of fed-batch reactors, which appear in a textbook on product and process design principals, relevant to the problem at hand, which is the optimization of product yield in a batch process.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the target mass by routine experimentation, and thereby arrive at the limitations of the instant claims. One of ordinary skill in the art would have been motivated to do so in order to optimize the costs and time associated with the process, as taught by Seider.
Regarding claims 5 and 6, modified Urza teaches the method of claim 1, where Kimura teaches the uranium comprising greater than 7.0% and up to 100% U-235 (Table between [0029] and [0030]), which includes the claimed ranges of greater than about 10% by weight U-235 isotope and greater than about 15% by weight U-235 isotope required by claims 5 and 6, respectively.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Regarding claim 7, modified Urza teaches the process of claim 1, where Urza teaches the inert gas is nitrogen (col. 5, lines 19-20).
Regarding claim 8, modified Urza teaches the method of claim 1, where the heating is sufficient to carry out the conversion of UF6 to UO2F2 in the reaction zone at 500 °C (col. 5, line 18 and col. 3 lines 17-18 and 40-41).
Regarding claim 9, modified Urza teaches the method of claim 1, where the heating is sufficient to carry out the conversion of UO2F2 -to UO2 in the fluidized bed at a temperature of 650 °C (col. 5, line 17 and col. 3 lines 58-60).
Regarding claims 16 and 19, Urza teaches a process for conversion of fluorinated uranium material (UF6) to produce feed for nuclear fuel (ceramic grade uranium oxide; abstract), comprising the following steps:
providing a seed bed of uranium dioxide (UO2) powder in a fluidized bed reactor vessel (uranium oxide material approximating UO2 was charged into the fluidized bed section of the reactor to establish the initial bed of fluidized solids; col. 5, lines 12-16);
fluidizing the UO2 powder in the reactor vessel using an upflow stream comprising nitrogen gas, while heating the reactor vessel to a temperature of at 500 °C in a top portion of the reactor vessel and 650 °C in the a bottom portion of the reactor vessel (the fluidized bed section [bottom portion] and the reaction zone [top portion] of the vessel were maintained at 650 °C and 500 °C, respectively; col. 5, lines 16-18), and feeding a stream of hydrogen and steam to the upflow stream of inert gas (a preheated mixture of nitrogen, hydrogen, and steam was used to fluidize the bed; col. 5, lines 19-20; Fig. 1 shows it is in an upflow reactor);
feeding vaporized uranium hexafluoride (UF6) and additional steam to the fluidized bed reactor vessel (uranium hexafluoride was fed into the reaction zone with preheated steam; col. 5, lines 20-21)
hydrolyzing the UF6 with some of the steam to yield uranyl fluoride (UO2F2) (uranyl fluoride formed; col. 5, line 34; conversion of uranium hexafluoride with superheated steam …to produce submicron Uranyl fluoride; col. 1, lines 59-61 and Eq. 1);
reacting the UO2F2 with the hydrogen in the upflow stream to yield additional UO2 powder (the product was granular, free flowing …the composition of the fluoride containing uranium oxide was 87.1 weight percent uranium and 0.24 weight percent fluoride, which shows that most of the UO2F2 (77.3% U, 12.3% F) is converted to UO2 (88.1% U,0 0% F); col. 5, lines 39-42; Eq. 2 shows this is by reaction with hydrogen) which accumulates in the fluidized bed (product from the reactor was routinely withdrawn to maintain a constant bed level; col. 5, lines 17-18); and,
stopping the feeding of UF6 and allowing any residual UF6 in the reactor vessel to react with the stream of hydrogen and steam to yield additional UO2 powder which accumulates in the fluidized bed (after the flow UF6 was terminated, the bed material was retained in the fluidized bed for 30 min for further defluorination; col. 5, line 43-44).
Because the UF6 was introduced together with additional steam (uranium hexafluoride was fed into the reaction zone with preheated steam; col. 5, lines 20-21) through a single concentric nozzle (col. 2, lines 26-28), terminating the UF6 stream is interpreted as also terminating the additional steam. Even if this were not the case, it would have been obvious to one of ordinary skill in the art to also terminate the additional steam because the reduction reaction with hydrogen is occurring in the fluidized bed and there is already steam being provided to this bed via line 16 (col. 2, lines 28-32) and steam entering above the bed via lines 13 and 14 (col. 2, lines 27-28 and Figure) would not be required.
Regarding the limitation where the stream of hydrogen and steam are stopped to enable discharge of a quantity of the UO2 powder from the reactor vessel, it is noted that it would be obvious to at some point shut down the reactor of Urza and to remove the products, thereby meeting this claim limitation.
Urza does not teach the UO2 powder or the UF6 comprising uranium with greater than 10% by weight U-235 isotope, making them HALEU materials, nor does Uraz teach the process being a semi-batch process where the UF6 and additional steam feed is stopped when the UO2 in the fluidized bed reaches a target mass.
However, Kimura teaches a reactor for conversion of UF6 to UO2 (title) and further teaches that their reactor can be used for the specific operations outlined by Urza (US Pat. 4,830,841) on U-235 enriched materials ([0026]). Kimura further teaches that these materials can be 6.0%, 7.0% and up to 100% enriched in U-235 (Table between [0029] and [0030]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the method of Urza for enriched UF6 (fluorinated HALEU material) and enriched UO2 to produce HALEU feed, where the weight percent of uranium U-235 in the uranium of UF6 and UO2 is up to 100%, which includes the instantly claimed ranges of greater than 10%, as required by claim 16, and greater than 15%, as required by claim 19. One of ordinary skill in the art would have been motivated to do so because Kimura teaches that their modification allowing use of Urza’s method on higher weight percent U-235 represents an improvement on the method of Urza ([0024]).
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Regarding the limitation where the process is a semi-batch process, Seider teaches that it is often desirable to use batch or semi-batch (semicontinuous) processes where reactant feed is stopped and product is discharged (Figure 22.1) when the chemicals are hazardous or toxic of when safety aspects are of great concern (Section 22.1, ¶ 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adapt the method of Urza to a semi-batch process. One of ordinary skill in the art would have been motivated to do so because safety aspects are of great concern with enriched uranium and Seider teaches that when that is the case one may want to opt for a semi-batch process.
Regarding the limitation where the UF6 and additional steam feed is stopped when the UO2 in the fluidized bed reaches a target mass, because Urza teaches that the UF6 and steam feed is stopped to allow for a 30 min period where reduction is allowed to occur (after the flow of UF6 was terminated, the bed material was retained in the fluidized bed for 30 minutes for further defluorination and reduction; col. 5, lines 42-45), it would have been obvious in a semi-batch process to base the time at which this termination occurred on some process parameter linked to reaction progress, and therefore also related to the amount of UO2 accumulated in the fluidized bed. One of ordinary skill in the art would have been motivated to base the point on which the feed of UF6 and additional steam is stopped on the amount of UO2 in the fluidized bed in order to optimize batch time, as taught by Seider (Section 22.2) and to avoid overfilling of the reactor with accumulated product.
Regarding claim 17, modified Urza teaches the method of claim 16, where Urza further teaches collecting the UO2F2 formed in step e) using a sintered metal filter located near the top of the reactor vessel, and periodically blowing the UO2F2 off of the filter using nitrogen blowback of the filter, causing the UO2F2 to drop toward the fluidized bed (uranyl fluoride formed was collected on a sintered metal filter [equipped with means to blow the solids back with a pulse of compressed nitrogen] located above the reaction zone and blown back, from time to time, into the fluidized bed; col 5, lines 34-36 and col. 2, lines 41-43).
Regarding claim 18, modified Urza teaches the method of claim 17 where the step of reacting the UO2F2 with the hydrogen in the upflow stream occurs in the fluidized bed (the defluorination/reduction of uranyl fluoride in fluidized bed 15; col. 3, lines 58-60).
Regarding claim 20, Urza teaches a process for conversion of fluorinated uranium material (UF6) to produce feed for nuclear fuel (ceramic grade uranium oxide; abstract), comprising the following steps:
providing a seed bed of uranium dioxide (UO2) powder in a fluidized bed reactor vessel (uranium oxide material approximating UO2 was charged into the fluidized bed section of the reactor to establish the initial bed of fluidized solids; col. 5, lines 12-16);
fluidizing the UO2 powder in the reactor vessel using an upflow stream comprising inert gas (nitrogen), while heating the reactor vessel (the fluidized bed section and the reaction zone of the vessel were maintained at 650 °C and 500 °C, respectively; col. 5, lines 16-18), and feeding a stream of hydrogen and steam to the upflow stream of inert gas (a preheated mixture of nitrogen, hydrogen, and steam was used to fluidize the bed; col. 5, lines 19-20; Fig. 1 shows it is in an upflow reactor);
feeding vaporized uranium hexafluoride (UF6) and additional steam to the fluidized bed reactor vessel (uranium hexafluoride was fed into the reaction zone with preheated steam; col. 5, lines 20-21)
reacting the UF6 with some of the steam to yield uranyl fluoride (UO2F2) (uranyl fluoride formed; col. 5, line 34; conversion of uranium hexafluoride with superheated steam …to produce submicron Uranyl fluoride; col. 1, lines 59-61 and Eq. 1);
reacting the UO2F2 with the hydrogen in the upflow stream to yield additional UO2 powder (the product was granular, free flowing …the composition of the fluoride containing uranium oxide was 87.1 weight percent uranium and 0.24 weight percent fluoride, which shows that most of the UO2F2 (77.3% U, 12.3% F) is converted to UO2 (88.1% U,0 0% F); col. 5, lines 39-42; Eq. 2 shows this is by reaction with hydrogen) which accumulates in the fluidized bed (product from the reactor was routinely withdrawn to maintain a constant bed level; col. 5, lines 17-18); and,
stopping the feeding of UF6 and allowing any residual UF6 in the reactor vessel to react with the stream of hydrogen and steam to yield additional UO2 powder which accumulates in the fluidized bed (after the flow UF6 was terminated, the bed material was retained in the fluidized bed for 30 min for further defluorination; col. 5, line 43-44).
Because the UF6 was introduced together with additional steam (uranium hexafluoride was fed into the reaction zone with preheated steam; col. 5, lines 20-21) through a single concentric nozzle (col. 2, lines 26-28), terminating the UF6 stream is interpreted as also terminating the additional steam. Even if this were not the case, it would have been obvious to one of ordinary skill in the art to also terminate the additional steam because the reduction reaction with hydrogen is occurring in the fluidized bed and there is already steam being provided to this bed via line 16 (col. 2, lines 28-32) and steam entering above the bed via lines 13 and 14 (col. 2, lines 27-28 and Figure) would not be required.
Regarding the limitation where the stream of hydrogen and steam are stopped to enable discharge of a quantity of the UO2 powder from the reactor vessel, it is noted that it would be obvious to at some point shut down the reactor of Urza and to remove the products, thereby meeting this claim limitation.
Urza does not teach the UO2 powder or the UF6 comprising uranium with greater than 19.75% by weight U-235 isotope, making them HALEU materials, nor does Uraz teach the process being a semi-batch process where the UF6 and additional steam feed is stopped when the UO2 in the fluidized bed reaches a target mass.
However, Kimura teaches a reactor for conversion of UF6 to UO2 (title) and further teaches that their reactor can be used for the specific operations outlined by Urza (US Pat. 4,830,841) on U-235 enriched materials ([0026]). Kimura further teaches that these materials can be 6.0%, 7.0% and up to 100% enriched in U-235 (Table between [0029] and [0030]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the method of Urza for enriched UF6 (fluorinated HALEU material) and enriched UO2 to produce HALEU feed, where the weight percent of uranium U-235 in the uranium of UF6 and UO2 is up to 100%, which includes the instantly claimed ranges of greater than 19.75%. One of ordinary skill in the art would have been motivated to do so because Kimura teaches that their modification allowing use of Urza’s method on higher percent U-235 represents an improvement on the method of Urza ([0024]).
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Regarding the limitation where the process is a semi-batch process, Seider teaches that it is often desirable to use batch or semi-batch (semicontinuous) processes where reactant feed is stopped and product is discharged (Figure 22.1) when the chemicals are hazardous or toxic of when safety aspects are of great concern (Section 22.1, ¶ 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adapt the method of Urza to a semi-batch process. One of ordinary skill in the art would have been motivated to do so because safety aspects are of great concern with enriched uranium and Seider teaches that when that is the case one may want to opt for a semi-batch process.
Regarding the limitation where the UF6 and additional steam feed is stopped when the UO2 in the fluidized bed reaches a target mass, because Urza teaches that the UF6 and steam feed is stopped to allow for a 30 min period where reduction is allowed to occur (after the flow of UF6 was terminated, the bed material was retained in the fluidized bed for 30 minutes for further defluorination and reduction; col. 5, lines 42-45), it would have been obvious in a semi-batch process to base the time at which this termination occurred on some process parameter linked to reaction progress, and therefore also related to the amount of UO2 accumulated in the fluidized bed. One of ordinary skill in the art would have been motivated to base the point on which the feed of UF6 and additional steam is stopped on the amount of UO2 in the fluidized bed in order to optimize batch time, as taught by Seider (Section 22.2) and to avoid overfilling of the reactor with accumulated product.
Regarding claim 21, modified Urza teaches the process of claim 20, where Urza also teaches discharging enough of the UO2 powder from the reactor vessel to leave behind a bed of UO2 powder (product from the reactor was routinely withdrawn to maintain a constant bed level; col. 5, lines37-38) as well as reusing the uranium dioxide from a previous run (col. 2, line 34), which implies a second run of the process can be performed and such a repeat run would entail repeating steps b to h.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to discharge enough of the UO2 powder from the reactor vessel to leave behind a seed bed of UO2 powder and repeating steps b) to h). One of ordinary skill in the art would have been motivated to do so because this would simplify the procedure and not require discharging all the UO2 only to reload it for use in the next run.
Claims 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Urza (US 4,830,841 A) in view of Kimura et al. (US 2011/0110837 A1) and Seider et al. (Product and Process Design Principles - Synthesis, Analysis, and Evaluation (4th Edition), Chapter 22. Optimal Design and Scheduling of Batch Processes. New York: John Wiley & Sons, Inc. 2017), as applied to claim 1 above, and further in view of Welty (US 3,578,419).
Regarding claim 10, modified Urza teaches the method of claim 1, and further teaches mixing the UO2 produced with U3O8 to reduce sintered density (column 5, lines 52-53), but does not teach discharging the quantity of UO2 powder from the reactor vessel and reacting the discharged UO2 powder with oxygen to yield triuranium octoxide (U3O8).
However, Welty teaches reacting UO2 powder with oxygen (from air; col. 3, line 34) to yield triuranium octoxide (converts hard scrap UO2, which may be in the form of a grinding residue to a millable U3O8; col. 3, lines 17-22).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to convert the UO2 powder obtained from the method of modified Urza to U3O8 powder according to the method of Welty, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because Urza teaches a need for U3O8 to mix with the UO2 powder obtained by their methods and Welty provides a synthesis of such a powder from the available UO2.
Regarding claim 11, modified Urza teaches the method of claim 10, where Welty teaches reacting of the UO2 powder with oxygen (as a component of air) to yield U3O8 in a second fluidized bed reactor vessel (col. 5, lines 53-56) at a temperature of about 470 °C (850 °F; col. 5, line 63).
Claims 12-15 are rejected under 35 U.S.C. 103 as being unpatentable over Urza (US 4,830,841 A) in view of Kimura et al. (US 2011/0110837 A1) and Seider et al. (Product and Process Design Principles - Synthesis, Analysis, and Evaluation (4th Edition), Chapter 22. Optimal Design and Scheduling of Batch Processes. New York: John Wiley & Sons, Inc. 2017), as applied to claim 1 above, and further in view of Figueroa et al. (Uranium Dioxide Conversion, Argonne National Lab, ANL/CSE-13/25. 2008. DOI: 10.2172/1159227).
Regarding claim 12, modified Urza teaches the method of claim 1, but does not teach reacting the discharged UO2 powder with hydrogen fluoride gas to yield uranium tetrafluoride (UF4).
However, Figueroa teaches a method of producing uranium metal from uranium dioxide in high yield with minimum waste production by first reacting UO2 with hydrogen fluoride gas (p. 2, ¶ 1-2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to react the discharged UO2 powder from the method of Urza with hydrogen fluoride gas to yield uranium tetrafluoride (UF4). One of ordinary skill in the art would have been motivated to do so because Figueroa teaches that this reaction is the first step in making uranium metal that can be used in fuel fabrication (uranium dioxide, which is ultimately converted through nonaqueous processes to metallic uranium that is recycled to fuel fabrication; p. 1).
Regarding claim 13, modified Urza teaches the method of claim 12, where Figueroa teaches the reaction of UO2 with hydrogen fluoride gas occurs in a fluidized bed reactor at temperatures in the range of 300 °C to 500 °C (p. 2, ¶ 3), which overlaps with the instantly claimed range of temperature of about 400 °C to about 500 °C.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Regarding claims 14 and 15, modified Urza teaches the method of claim 12, where Figueroa further teaches reacting the UF4 with calcium metal, an alkaline earth metal, to produce uranium metal at a temperature of about 500 °C (p. 2, ¶ 4-5). Figueroa also teaches that this reduction can be carried out in a pressure and temperature-resistant vessel (a ceramic crucible or liner and a steel containment or bomb assembly; p. 7, ¶ 2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further react the UF4 produced by the method of modified Urza with calcium metal to produce uranium metal at a temperature of about 500 °C in a pressure and temperature-resistant vessel, as taught by Figueroa. One of ordinary skill in the art would have been motivated to do so because this reaction produces the uranium metal sought for fuel fabrication in high yield with low waste production, as taught by Figueroa.
Response to Arguments
Applicant's arguments filed 1 February 2026 have been fully considered but they are not persuasive.
Applicant argues on pages 11-12 that Urza requires a secondary rotary kiln to achieve ceramic grade uranium dioxide and that the process is specifically designed to operate continuously. However, Urza (Example 1, col. 5) also teaches that UO2 with fluorine content of only 50 ppm can be obtained by stopping the flow of UF6, which cannot be considered a fully continuous process. So while Seider was used to further motivate a semi-batch process, the makings of such a process were already taught by Urza.
Furthermore, while Urza does say “Normally, product from the fluid bed is passed through a rotary kiln ..”, this does not mean that it is always required. In fact, there is no indication that the UO2 product obtained in Example 1 was passed to the rotary kiln; to the contrary, the low fluorine content of this product is noted and “it was used to test pelletizing and sintering characteristics” (col. 5, lines 47-48, emphasis added).
Applicants arguments against Kimura, page 13, are also not persuasive. Here Applicant argues that Kimura does not teach the modification to a semi-batch process. However, Kimura is not used to teach this modification. Kimura is only introduced to teach using HALEU materials in the process of Urza, which Applicant does not dispute.
Applicant’s arguments with respect to Seider, pages 13-15, are also not persuasive.
Applicant is correct that Seider does not teach that “safety aspects are of great concern with enriched uranium,” but Applicant does not dispute that such a fact would have been well known to one of ordinary skill in the art. That Seider does not teach this specific safety concern does not make their general teaching around the safety of batch processes any less pertinent. In fact, safety was also cited as a motivating factor for the instant invention, as noted in the reply, page 10.
Regarding Applicant’s assertion that Seider does not teach how to modify Urza, it is again noted that Urza already suggests a semi-batch process in their Example 1 by stopping the flow of UF6 to obtain UO2 with a fluorine content of 50 ppm. In fact, this stopping of the flow to complete the defluorination could itself be considered as making the process “semi-batch”, and renders the modification to a full “semi-batch” process obvious. What Urza specifically lacks is identifying the process as “semi-batch” and the teaching to stop the UF6 feed when the UO2 in the fluidized bed reaches the target accumulated mass. Seider completes the teaching of these modifications by teaching the use of a semi-batch process when safety is of concern and teaching optimization of batch time. The “semi-batch” process of Seider would lead one to not routinely withdraw product and the optimization of batch time would lead one to using a target accumulated mass, as analyzed above.
Applicant’s conclusion that Seider’s modification would lead one to simply stop and discharge the product ignores the teaching of Urza that retaining product in the fluidized bed for 30 min after stopping UF6 flow affords defluorination to 50 ppm, and that under these conditions Urza’s product did not require secondary processing in a rotary kiln, even if that was referenced as normal practice. Applicant’s final arguments regarding Seider are that Examiner’s reasoning conflates “safety” with “nuclear criticality safety”. Applicant then notes that nuclear criticality safety is addressed “not merely by using batch processing but by using smaller equipment with specific geometric and mass constraints”, and that Seider does not teach these features.
In response to this argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., smaller equipment and specific geometric and mass constraints) are not recited in the rejected claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, pages 15-16, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
The safety concerns raised by Seider, and amplified by Kimura’s teaching to use HALEU material, mean that pursuing a batch mode process would have been an obvious modification even without hindsight reasoning.
Furthermore, as noted above, Urza themselves hints at semi-batch process, where stopping the flow of UF6 and residing in the reactor for 30 min affords fluorination levels of 50 ppm, which are below the general range cited for the continuous process (0.1 to 1.2 weight percent; col. 3, lines 65-col. 4, line 1). Urza further teaches that the low levels of fluorine obtained by this batch-like operation allow the product to be directly pelletized and sintered (“Since the product was relatively low in fluoride, it was used to test pelletizing and sintering characteristics of the powder”; col. 5, lines 47-48, emphasis added), and that the pellets so formed have density (95.0-95.4% of the theoretical density; col. 5, line 56) comparable to those obtained following a secondary treatment (94.2% of the theoretical density; col. 6, line 32). These teachings of Urza render the modification to a semi-batch process even more obvious without any reliance upon Applicant’s disclosure.
Applicant’s conclusion that a person of ordinary skill in the art would have understood that Urza’s use of a secondary kiln applies to the batch mode process is also unfounded in view of Urza’s Example 1 which does not utilize a secondary treatment.
Conclusion
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally Merkling can be reached at (571) 272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
Prosecution Insights