DETAILED ACTION
Response to Amendment
A Reply was filed 10 March 2026. All amendments therein have been entered. Claims 1-6, 10, and 12-31 are pending.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Initial Comments
It is well-known that irradiating a UO2 target with thermal neutrons will produce fission products that include molybdenum. 99Mo is a common fission product of uranium-235. A certain percent of the fissions of U-235 result in the production of 99Mo. Thus, neutron irradiation of UO2 will inherently produce 99Mo.
Known Recoil Escape: The fission recoil range of a fission product like 99Mo is approximately 7.15 μm in UO2. As a result, for a reusable or porous UO2 target to work without dissolving the uranium, the UO2 particle diameter should be less than this 7.15 μm range so that nearly 100% of the produced 99Mo is ejected into the pores or surrounding medium. Thus, Applicant’s claim 1 is directed to well-known features.
Claim Rejections - 35 USC § 102(a)(1)
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Czerwinski (US 2016/0189816).
Czerwinski (cited via IDS) teaches a UO2 target having a porous matrix comprising particles of UO2. The particles have a size of less than 7.15 μm. The target is structurally capable of being used in the manufacture of 99Mo. Particularly note Czerwinski at paragraphs [0008, 0013, 0017, 0018, 0020, 0022, 0024, 0049, 0060, 0100-0104, and 0205].
Claim Rejections - 35 USC § 103
Claims 1-6, 10, 12, and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Raposio (Development of LEU-based targets for radiopharmaceutical manufacturing: A review; 2019) in combination with Bertch (Selective Gaseous Extraction: Research, Development And Training For Isotope Production; 2014).
Claim 1
Raposio discloses that the penetration range of 99Mo in a UO2 target is 7.15 μm. As result thereof, the UO2 particles should have a size of 6 ± 1 μm (section 3.3).
Bertch shows that it is well known in the art to use a porous UO2 target so that gas can be used to extract the produced 99Mo (e.g., abstract; page 20).
Modification of Raposio to have included a porous UO2 target to allow for gas extraction of produced 99Mo, as suggested by Bertch, would have been obvious to one of ordinary skill in the art. The result of the modification would have been predictable to the skilled artisan.
Claims 2 and 4-6
Raposio discloses using enrichments of 1.8 – 2.2% (section 3.1).
Claims 3, 10, and 12
Raposio discloses using a uranium density of around 9.7 g/cm3. It would have been obvious to one of ordinary skill in the art to have the UO2 density range in the matrix be modified (if necessary) so that it is based on the desired output of 99Mo.
Claims 16-20
Raposio discloses the methods. Nevertheless, to have optimized the target, and the irradiation lengths, to have produced the desired output of 99Mo would have been obvious to one of ordinary skill in the art.
Claims 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Raposio in combination with Bertch as applied to claim 1 above, and further in view of Peryoga ("Inherent protection of plutonium by doping minor actinide in thermal neutron spectra"; 2005).
Peryoga shows that it is well known in the art to dope a UO2 target with 237Np to reduce proliferation concerns arising from 239Pu build-up. Also note the discussion of Peryoga in Applicant’s published specification at [0054]. Modification of Raposio to have included 237Np doping to have reduced 239Pu proliferation, as suggested by Peryoga, would have been obvious to one of ordinary skill in the art.
Allowable Subject Matter
Claim 13 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 21-31 are allowable over the prior art of record.
Response to Arguments
Applicant's arguments have been fully considered but not all are persuasive.
Applicant argues that “the Examiner has apparently alleged that Czerwinski's (grain size) is relevant to the recited particle (size), and there is no basis for the Examiner to do so” (Remarks at page 13).
The Examiner respectfully disagrees. The Examiner notes that Czerwinski indicates that the target may include “grains containing uranium oxide . . . having an average particle size of less than an average recoil distance of 99Mo as a fission product of uranium” [0008], and “the grains are particles of uranium oxide . . . having a grain size from about 0.001 to 10 micrometers” [0018]. Thus, Czerwinski anticipates claim 1.
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 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.
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 and/or the specification.
Contact Information
Examiner Daniel Wasil can be reached at (571) 272-4654, on Monday-Thursday from 10:00-4:00 EST. Supervisor Jack Keith (SPE) can be reached at (571) 272-6878.
/DANIEL WASIL/
Examiner, Art Unit 3646
Reg. No. 45,303
/JACK W KEITH/Supervisory Patent Examiner, Art Unit 3646
Prosecution Insights