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. Claims 1, 4-16, and 18-23 are pending in this application and examined herein.
Response to Arguments
2. The arguments dated 11/05/25 have been fully considered but are largely directed to newly added claim limitations. The arguments are therefore addressed in the rejections below.
3. Regarding Lahoda, Applicant’s arguments state “Lahoda requires that the combined amount of Y and Zr be at 0.1-20%.” The examiner disagrees that this is a “requirement” of Lahoda. Rather, that is what Lahoda discloses, but Lahoda provides no technical or logical reason that the Y+Zr content in its chromium coating must be within this range. There is no teaching away from modification of the Y+Zr content in Lahoda (MPEP 2145(X)(D)) nor is there any evidence that a modification to the Y+Zr content would render the coating of Lahoda unsuitable for its intended use or change its principle of operation (MPEP 2143.01(V, VI).
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 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, 4-13, and 18-23 are rejected under 35 U.S.C. 103 as being unpatentable over Lahoda et al., US 2018/0025793 in view of Gu et al., “Chromium and Chromium-Based Alloys,” in further view of Ryan, “An Appraisal of Possible Scavenger Elements for Chromium and Chromium Alloys.”
8. Regarding claims 1, 8, 9, 16, and 21, Lahoda discloses a nuclear fuel rod ([0003], [0028], claim 6) comprising:
a cladding material housing nuclear fuel ([0003], [0009]; [0015]); and a chromium alloy coating layer ([0011]) applied to the substrate ([0010]), wherein the chromium alloy coating comprises: chromium, yttrium, and zirconium ([0011]).
Lahoda is silent as to the amount of interstitial elements in its chromium coating. Gu teaches that, in chromium, “removal of nitrogen (and possibly other similar elements) to extremely low levels, certainly <0.0001%1, should result in adequate ductility in all conditions” and that “that suitable
ductility can be found in chromium or chromium alloys of lesser purity” (p. 29) Accordingly, one of ordinary skill in the art at the time of invention/filing would have been motivated to ensure the purity of the chromium coating of Lahoda to the interstitial element content taught by Gu, which is within the claimed range, so as to “increase the ductility at low temperature” (p. 29).
Lahoda further discloses that its chromium coating comprises “a combined content of 0.1-20%” Y+Zr, a range that nearly touches the claimed range of “up to 0.5% Y and up to 0.4% Zr.” Thus, the claimed range would have been obvious to a skilled artisan (MPEP 2144.05(I)). Moreover, Gu states “Ce, Ti, Y, and Zr additions [to chromium] promote room-temperature ductility,”2 which would motivate one to discover the optimum or workable range of such additions that would achieve a desired ductility by routine experimentation. (See MPEP 2144.05)
Furthermore, Ryan teaches “stoichiometric additions” of Y and Zr to chromium to act as a scavenger for nitrogen and oxygen (See Table II, Table III) interstitial impurities, concluding that “effective scavenging of interstitial impurities in commercial grades of Cr has been achieved with stoichiometric additions of Ce, Ti, Y, and Zr” (Summary on p. 21). Ryan adds ~0.4% Y or Zr to counteract ~0.4% N or C (Tables II and IV); ~0.5% to counter ~1% oxygen (Table III). Thus, a skilled artisan would be motivated to employ the teaching of Ryan in the coating of Lahoda as modified by the purity of Gu. Further, one skilled in the art would select the amount of Y and Zr scavenging atoms in the chromium alloys coating of Lahoda based on the amount if interstitial impurities present in the chromium of the coating. So, Gu’s “<0.0001%” interstitial element content would require a “stoichiometric addition” of Y and Zr, which would fall within the ranges recited in claims 1, 16 and 21.
For 100 ppm each of N, O, and C, a skilled artisan would readily recognized based on Ryan, that Y and Zr additions would need to total 250 ppm (because the stoichiometric ratios are 1 Y or Zr : 1N, 1:1C, and 1:2O), or 0.025%. For 300 ppm each, the Y and Zr additions would total 750 ppm, or 0.075%. For 500 ppm each of N, C, and O, one would need 1250 ppm Y+Zr, or 0.125%.
9. Regarding claims 4, 20, and 22, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claims 1, 16, and 21 obvious. Lahoda is silent as to the ductility of its chromium coating. However, Gu establishes that the Cr doped with Y+Zr alloy disclosed at [0094-5] would possess this physical property (see the “Alloying” subsection starting on p. 29).
10. Regarding claims 5, 6, 18, 19, and 23, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claims 1, 16, and 21 obvious. Gu teaches that, in chromium, “removal of nitrogen (and possibly other similar elements) to extremely low levels, certainly <0.0001%3, should result in adequate ductility in all conditions” and that “that suitable ductility can be found in chromium or chromium alloys of lesser purity” (p. 29) Accordingly, one of ordinary skill in the art at the time of invention/filing would have been motivated to ensure the purity of the chromium coating of Lahoda to the interstitial element content taught by Gu, which is within the claimed range, so as to “increase the ductility at low temperature” (p. 29).
11. Regarding claim 7, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claim 1 obvious. further discloses its chromium coating has a thickness of 5-100 microns ([0013]), a range which overlaps the claimed range. Accordingly, the claimed range is obvious.
12. Regarding claims 10-12, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claim 1 obvious. Lahoda is silent as to the fuel within its fuel rod cladding, but does disclose that the fuel rod cladding is for use in light water reactors, including BWRs and PWRs ([0018]). It is well-known in the art that such reactors employ fuel rods containing UO2 fuel pellets.4 Accordingly, it would have been obvious to include such fuel in the claddings of Lahoda.
13. Regarding claim 13, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claims 1 obvious. Lahoda further discloses that its chromium coating is applied by a cold spray process ([0028]).
14. Claims 14 and 15 are not addressed further on prior art grounds here because they further limit an alternative limitation of claim 13.
15. Claims 7 and 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Lahoda et al., US 2018/0025793 in view of Gu et al., “Chromium and Chromium-Based Alloys,” and Ryan, “An Appraisal of Possible Scavenger Elements for Chromium and Chromium Alloys,” in further view of Brachet et al., US 2017/0287578.
16. Regarding claim 7, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claim 1 obvious. Lahoda does not explicitly disclose a coating thickness of 0-25 microns. Brachet teaches a nuclear fuel rod (Fig. 7A, [0218]), comprising:
a substrate (1); and a chromium alloy coating layer (2) applied to the substrate wherein the chromium alloy coating layer is up to 25 microns in thickness ([0130]: most preferably 3-25 microns). One of ordinary skill in the art at the time of the invention/filing would have found it obvious to apply the coating thickness taught by Brachet to the fuel rod of Lahoda because it is within the range disclosed in Lahoda Brachet teaches that such a thickness provides sufficient protection from deterioration (see [0221]).
17. Regarding claims 13-15, Lahoda as modified by the chromium purity taught by Gu and the stoichiometric Y+Zr additions of Ryan renders claim 1 obvious. Lahoda’s coating is applied by a cold spray process ([0028]). Brachet teaches . Brachet teaches a nuclear fuel rod (Fig. 7A, [0218]), comprising:
a substrate (1); and a chromium alloy coating layer (2) applied to the substrate wherein the chromium alloy coating later is applied by magnetron sputtering deposition ([0026]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to use the coating method of Brachet for the fuel rod coating of Lahoda because Brachet teaches that this process improves resistance to oxidation and/or hydriding ([0037]).
Interviews
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Finality
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHARON M DAVIS whose telephone number is (571)272-6882. The examiner can normally be reached Monday - Thursday, 7:00 - 5:00 pm ET.
If attempts to reach the examiner by telephone are unsuccessful, the examiner' s supervisor, Jack Keith can be reached at 571-272-6878. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SHARON M DAVIS/Primary Examiner, Art Unit 3646
1 1 ppm
2 One of the references cited by Gu appears to be directly relevant to the patentability of claims 2, 3, and 17, but the examiner does not have access to the full text of the article: Ryan, N. E. "An appraisal of possible scavenger elements for chromium and chromium alloys." Journal of the Less Common Metals 6.1 (1964): 21-35.
3 1 ppm
4 https://www.nrc.gov/reading-rm/basic-ref/glossary/fuel-rod; https://www.nrc.gov/reading-rm/basic-ref/glossary/pellet-fuel
Prosecution Insights