Prosecution Insights
Last updated: April 19, 2026
Application No. 18/520,976

Steam Separator and Boiling Water Reactor Including Same

Non-Final OA §102
Filed
Nov 28, 2023
Examiner
WILSON, GREGORY A
Art Unit
3762
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Hitachi GE Vernova Nuclear Energy Ltd.
OA Round
1 (Non-Final)
82%
Grant Probability
Favorable
1-2
OA Rounds
2y 11m
To Grant
88%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
965 granted / 1181 resolved
+11.7% vs TC avg
Moderate +7% lift
Without
With
+6.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
29 currently pending
Career history
1210
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
34.8%
-5.2% vs TC avg
§102
39.9%
-0.1% vs TC avg
§112
22.1%
-17.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1181 resolved cases

Office Action

§102
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 . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Claim Rejections - 35 USC § 102 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. The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 1, 2, 4, 5 and 10 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by JP2012058113 (JP ‘113). JP ‘113 discloses a steam separator (10) includes a plurality of stages of separating mechanisms (SEE for example Figures 3-4), a separating mechanism in a first stage from a bottom including a stand pipe (1) that guides a mixed fluid of steam generated by a reactor core and water upward from below, a diffuser (6) that communicates with an upper side end surface of the stand pipe (SEE Figures 3 & 4) to form a flow passage, and expands a flow passage cross-sectional area toward an upward direction more than a flow passage cross-sectional area of the upper side end surface (Figures 3 & 4), a first stage inner cylinder (3a) that communicates with an upper side end surface of the diffuser to form a flow passage, a swirler (2) that includes a hub passing through an axial center of the flow passage of a mixed flow of the steam and the water and a plurality of swirl vanes attached radially with the hub as a center, the swirl vanes having an inner edge fixed to the hub in a radial direction of the swirl vanes (the swirler is fixed to the diffuser), and having an outer edge fixed to an inner wall of the diffuser or an inner wall of the first stage inner cylinder in the radial direction of the swirl vanes, a first stage outer cylinder (4a) that forms a first stage discharge port (8a) in a lower part of a first stage annular flow passage (interpreted as the space between the inner cylinder and outer cylinder) formed so as to be concentrically spaced from and surround the first stage inner cylinder, a first stage annular plate (SEE Annotated Figure 1) that covers an upper side surface of the first stage outer cylinder, and forms a circular hole having a smaller diameter than the first stage inner cylinder (3a), and a first stage pickoff ring (5a) that is extended downward in a tubular shape from an inner circumferential edge forming the circular hole of the first stage annular plate (Figures 3 & 4), and forms the circular hole as a short flow passage to a second stage inner cylinder (3b), and a separating mechanism in a second or subsequent stage from the bottom including a second or subsequent stage inner cylinder (3b) that is installed on the annular plate in a preceding stage to form a flow passage, a second or subsequent stage outer cylinder (4b) that forms a second or subsequent stage discharge port (8b) in a lower part of a second or subsequent stage annular flow passage (interpreted as being between the second inner and second outer cylinder) formed so as to be concentrically spaced from and surround the second or subsequent stage inner cylinder, a second or subsequent stage annular plate (SEE Annotated Figure 1) that covers an upper side surface of the second or subsequent stage outer cylinder, and forms a circular hole having a smaller diameter than the second or subsequent stage inner cylinder, and a second or subsequent stage pickoff ring (5b) that is extended downward in a tubular shape from an inner circumferential edge forming the circular hole of the second or subsequent stage annular plate, and forms the circular hole as a short flow passage to an inner cylinder in a next or subsequent stage or an outlet flow passage, the separating mechanism in the second or subsequent stage including a vertical plate (9) that divides the second or subsequent stage annular flow passage in a circumferential direction and eliminates a swirl component of the mixed flow continuously occurring from the second or subsequent stage inner cylinder to the second or subsequent stage annular flow passage. In re claim 2, JP ‘113 discloses that the vertical plate is installed such that an end surface in a vertical direction of the vertical plate is at an angle of 90 degrees with respect to an outer surface of the second or subsequent stage inner cylinder and an inner surface of the second or subsequent stage outer cylinder (SEE Figure 5, which illustrates that the vertical plate 9 extends 90 degrees from the side 4a). In re claim 4, JP ‘113 illustrates in Figure 5a that the vertical plate 9 extends between the inner cylinder (3a) and the outer cylinder (4a) contacting both cylinders. In re claim 5, JP ‘113 implicitly discloses that the vertical plate extends to the second or subsequent stage discharge port (the vertical plates can have various shapes depending on the location of the separator (SEE [0060]). In re claim 6, JP ‘113 discloses a boiling water reactor (Figure 1) including a nuclear reactor pressure vessel; a reactor core (11) that is provided within the nuclear reactor pressure vessel (15), and is loaded with a plurality of fuel assemblies; a shroud (12) in which the reactor core is disposed; a steam separator (10) that is disposed above the reactor core, and separates a mixed flow of steam generated by the reactor core and water into the steam and the water; a steam dryer (14) that is located above the steam separator, and dries wet steam separated by the steam separator; a main steam pipe (17) that supplies the steam dried by the steam dryer to a turbine; a downcomer (19) that is formed between the nuclear reactor pressure vessel and the shroud, and through which the water separated by the steam separator circulates; and a pump (16) that is disposed below the downcomer, and supplies the water within the downcomer to the reactor core, the steam separator being the steam separator according to claim 1. Allowable Subject Matter Claims 3 and 6-9 are 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. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Kondo et al (8,741,014) also teaches a vertical plate (swirl vane 9) for restricting the swirling flow of separated water in the separator. Any inquiry concerning this communication or earlier communications from the examiner should be directed to GREGORY A WILSON whose telephone number is (571)272-4882. The examiner can normally be reached M-F; 7:00am-4:30pm. 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, Steve McAllister can be reached at 571-272-6785. 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. /GREGORY A WILSON/Primary Examiner, Art Unit 3762 February 3, 2026
Read full office action

Prosecution Timeline

Nov 28, 2023
Application Filed
Feb 03, 2026
Non-Final Rejection — §102 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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CHILLING UNIT, HEAT TREATMENT APPARATUS INCLUDING SAME, AND HEAT TREATMENT METHOD
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2y 5m to grant Granted Apr 07, 2026
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2y 5m to grant Granted Mar 17, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
82%
Grant Probability
88%
With Interview (+6.7%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 1181 resolved cases by this examiner. Grant probability derived from career allow rate.

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