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 .
Claim Status
1. Claims 25-50 are pending with claims 34-48 withdrawn. Claims 25-33 and 49-50 are examined herein.
Response to Arguments
2. Regarding the claim rejections under 35 U.S.C. 112(b), the amendments have overcome the previous rejections. However, a new rejection is made based on the amended language of claim 25 (see below).
3. Regarding the rejections under 35 U.S.C. 102 and 103, all rejections under 102 are withdrawn in view of the claim amendments. A new ground of rejection under 35 U.S.C. 103 is presented below.
4. Regarding Brachet alone, the examiner does not agree that there is insufficient evidence to conclude that microdroplets absent in Brachet’s chromium coating. Brachet is concerned with corrosion resistance of zirconium alloy nuclear fuel claddings when coated with a chromium-based coating (see at least Abs.). The protection offered by such a coating is dependent on the integrity of the coating. A skilled artisan would reasonably expect that a coating characterized by the presence of defects would provide less protection than one without defects. This is shown by the experimentation depicted at Figs. 6A and B. Brachet does not observe any degradation in its HiPIMS-deposited chromium coatings (Fig. 6B) under exposure to high temperature steam, while a conventionally-applied chromium coating having a surface defect does degrade under the same conditions (Fig. 6A). If Brachet’s coatings had defects, it is reasonable to expect that the disclosure would remark on them because they would lead to the corrosion Brachet is explicitly trying to avoid. Similarly, de Montenyard is also concerned with the integrity of the coating (Abs.: “Oxidation resistance investigations show a barrier effect for all coatings.”) and does not remark on the presence of surface defects such as microdroplets. A skilled artisan would therefore reasonably conclude that no such surface defects exist in the coating, because they would affect the integrity of the coating and its protection against oxidation.
5. Regarding the optimization of Brachet based on the teaching of Jiang, Applicants arguments are not persuasive. Brachet explicitly states (with added emphasis):
[0152] In accordance with his general knowledge, a person skilled in the art may, however, easily adapt himself to these variations by modifying at least one of the parameters, such as, for example, the polarization voltage of the substrate which is applied during the step a) of ion etching or the step b) of deposition of the internal layer, the duration, the frequency, the intensity or the polarization voltage of the polarization impulses, the distance between the chromium target and the substrate, or the pressure of the carrier gas.
[0153] More particularly, these parameters influence the mean energy of the Cr+ Pions which are produced during steps a) or b). This energy can condition the density, the homogeneity, the texture, the microstructure or the state of stress of the external layer.
6. The instant disclosure indicates that the pressure and peak power density are key parameters influencing microdroplet formation (see [0132] of the published application). Yet, Brachet mentions both parameters as controlling the homogeneity, texture, and microstructure of the chromium coating produced by its HiPIMS process. Comparing the parameters listed in Table 1 of the instant disclosure to the parameters disclosed by Brachet (paragraphs [0118-0126], [0154-0168]), the biggest difference is in the intensity of the impulses, which in the instant invention is 30-70 W/cm2, while Brachet discloses 1000-5000 W/cm2. However, because Brachet explicitly recognizes “the intensity of the polarization impulses” as a factor influencing the microstructure of the coating, changing this parameter must therefore be considered routine optimization that would predictably affect the microstructure of the coating, as Brachet discloses.
7. Additionally, Jiang teaches that cracks formed from stress at microdroplet defects lead to oxidation and hydride embrittlement (p. 2). This appears to be what Brachet observes in high temperature steam exposure of a cathode sputtered chromium coating (Fig. 6A). No such degradation was observed in the HiPIMS-produced chromium coating (Fig. 6B), suggesting that Jiang’s teaching of minimizing can be effectively applied to Brachet to avoid microdroplet defects, and therefore the degradation resulting therefrom.
8. Regarding Applicants argument that “achieving such a low microdroplet density is not a trivial optimization” and the cited art cannot achieve the recited density threshold (Arguments p. 11), there is no objective evidence cited, so the arguments are not persuasive. Applicant has not established that the claimed microdroplet density is unexpected, given the teachings of the prior art (see MPEP 716.02). The evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance." Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992) It is the examiner’s position that a skilled artisan would find it obvious to avoid all microdroplet defects in the coating of Brachet, based on the disclosure of Jiang. That is, the prior art suggests that the optimal microdroplet density of Brachet’s coating is 0/mm2. Brachet explicitly suggests optimizing coating process parameters to influence coating microstructure (see above). Moreover, Brachet does not observe any degradation that would be expected if microdroplet defects were present in its coating. Applicant has not provided any objective evidence that such an optimization would be incapable of producing a coating with no microdroplet defects or that the preset invention’s properties are unexpected. The rejection is therefore maintained.
Claim Rejections - 35 USC § 112
9. 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.
10. Claims 25-33 and 49-50 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 pre-AIA the applicant regards as the invention.
11. Regarding claim 25, the recitations “a pure zirconium material comprising at least 99% by weight of zirconium” and “a pure chromium material comprising at least 99% by weight of chromium” are indefinite. “Pure” means “not mixed with anything else,” which contradicts the recitation of “at least 99%.” That is, a zirconium material comprising 1% other things would not be considered to meet the definition of the word pure. Additionally, this recitation is unclear because it contains both a broad recitation “at least 99% and a narrow recitation “pure.” Deletion of the word pure in these recitations would overcome this rejection.
12. Claims 26-33 and 49-50 are rejected because they depend on claim 25.
Claim Rejections - 35 USC § 103
13. 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.
14. 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.
15. 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.
16. Claims 25-30 and 49-50 are rejected under 35 U.S.C. 103 as being unpatentable over Brachet et al., US 2017/0287578 in view of Hertz et al., US 2018/0366234 in further view of Jiang, et al., “In-situ study on the tensile behavior of Cr-coated zircaloy for accident tolerant fuel claddings.”
17. Regarding claim 25, Brachet discloses a nuclear fuel cladding element (Fig. 7A, [0149], [0002]), the cladding element comprising: a substrate (1) made of a zirconium-based alloy containing at least 95% by weight of zirconium (0076-93]); and a protective coating (2) covering the substrate on an outside (see Fig. 7A), the protective coating being made of chromium material ([0094]), the protective coating having a columnar microstructure composed of columnar grains (Figs. 1B, C; [0094]).
Brachet is silent as to the purity of its chromium coating. Hertz teaches a nuclear fuel cladding element comprising a substrate and a protective coating covering the substrate on an outside, the protective coating being made of a pure chromium material comprising at least 99% by weight of chromium or a chromium-based alloys comprising at least 85% by weight of chromium ([0065-70]). One of ordinary skill in the art at the time of invention/filing would have found it obvious to apply the chromium coating materials taught by Hertz to the coating of Brachet for the predictable purpose of providing very good corrosion resistance and improved corrosion behavior under normal and accident conditions ([0160]).
Brachet is silent as to the presence of microdroplets on its protective coating, suggesting that such defects were not observed. Notably, Figs. 1A and 6B of Brachet show microstructures of its chromium coatings, and neither image reveals any microdroplet defects in the coating. A microdroplet defect appears in Fig. 6A, showing a chromium coating prepared by “a conventional cathode sputtering process” ([0213]), the surface defect leading to delamination of the coating and hydriding of the underlying zirconium substrate under high temperature steam exposure (see [0212-0216]). Additionally, de Monteynard and Ferreira extensively study the HiPIMS-deposited chromium coating of Brachet and also do not remark on the presence of microdroplet defects, providing extrinsic evidence that the coating of Brachet lacks such features.1
Nonetheless, Jiang teaches that microdroplet defects in chromium coatings for zirconium alloy nuclear fuel rods are deleterious (p. 4, last paragraph) and the stress-induced cracking at such defects “may lead to localized oxidation under accident conditions and cause significant degradation of the mechanical properties of the cladding by hydride embrittlement” (p. 2, first paragraph). Accordingly, a skilled artisan would have found it obvious to minimize microdroplet defects in the coatings of Brachet to a density of less than 100 per mm2, so as to mitigate the potential for local stress concentration leading to crack initiation and hydride embrittlement (p. 4, last paragraph; p. 2, first paragraph).
18. Regarding claims 26, 27, 49 and 50, Brachet as modified by Hertz and Jiang makes claim 25 obvious. Brachet further discloses columnar grains having an average diameter of 0.1-10 µm ([0097]). This range encompasses or overlaps the claimed columnar grain diameter ranges, making the claimed size range obvious over Brachet (MPEP 2144.05(I)).
19. Regarding claim 28, Brachet as modified by Hertz and Jiang makes claim 25 obvious. Because Brachet as modified by Jiang lacks microdroplet defects, Brachet makes obvious the claimed microdroplet size because the size of a non-present feature is not required.
20. Regarding claim 29, Brachet as modified by Hertz and Jiang makes claim 25 obvious. Brachet further discloses that its coating has a thickness of 2-50 µm, which encompasses the claimed thickness range of 5-25 µm, making the claimed thickness range obvious over Brachet (MPEP 2144.05(I)).
21. Regarding claim 30, Brachet as modified by Hertz and Jiang makes claim 25 obvious. Brachet fully discloses the first alternative limitation of the two possible chromium coating compositions recited in claim 25. Claim 30 further limits the second alternative limitation of claim 25. It is therefore not addressed further here.
22. Regarding claim 31, Brachet as modified by Hertz and Jiang makes claim 25 obvious. Brachet further discloses the cladding element being a cladding tube of a nuclear fuel rod ([0149], [0002]).
23. Claims 32 and 33 are rejected under 35 U.S.C. 103 as being unpatentable over Mazzoccoli et al., US 2015/0348652 in view of Brachet, Hertz, and Jiang as applied to claim 25 (above).
24. Regarding claims 32 and 33, Mazzoccoli discloses a nuclear fuel element comprising nuclear fuel (1) disposed within a cladding (2) closed by plugs (6) at ends thereof (see Fig. 3, [0031]).
As explained above, Brachet as modified by Hertz and Jiang makes obvious the cladding element of claim 25.
One of ordinary skill in the art at the time of invention/filing would have found it obvious to combine the cladding element taught by Brachet as modified by Hertz and Jiang to the fuel element of Mazzoccoli for the predictable purpose of “improv[ing] the resistance to oxidation and/or hydriding, among others in the presence of steam ([0021]).
Finality
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.
Interviews
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Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHARON M DAVIS whose telephone number is (571)272-6882. The examiner can normally be reached Monday - Thursday, 7:00 - 5:00 pm ET.
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/SHARON M DAVIS/Primary Examiner, Art Unit 3646
1 MPEP 2131.01(III): the cited NPL references are cited as extrinsic evidence.