John A. Blaisdell et al.

Patent Trials and Appeals Board

Oct 28, 2020

13798418 - (D) (P.T.A.B. Oct. 28, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/798,418 03/13/2013 JOHN A. BLAISDELL NSD 2011-024 6434
26353 7590 10/28/2020
WESTINGHOUSE ELECTRIC COMPANY LLC
K&L GATES LLP
210 SIXTH STREET
K&L Gates Center
PITTSBURGH, PA 15222-2613
EXAMINER
GARNER, LILY CRABTREE
ART UNIT PAPER NUMBER
3646
NOTIFICATION DATE DELIVERY MODE
10/28/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
uspatentmail@klgates.com
uspatentmail@klgates.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JOHN A. BLAISDELL, EDWARD M. CHU,
CAMILLA S. ROTANDER, and GURIKAR V. KUMAR
Appeal 2019-002438
Application 13/798,418
Technology Center 3600
Before STEFAN STAICOVICI, WILLIAM A. CAPP, and
NATHAN A. ENGELS, Administrative Patent Judges.
ENGELS, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–6. See Final Act. 1. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as Westinghouse
Electric Company LLC. Appeal Br. 2.
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CLAIMED SUBJECT MATTER
Appellant’s Specification states that “[t]he invention provides
methods for protecting against fuel damage and fuel cladding failures in
boiling water reactor . . . cores due to anticipated coupled thermal
hydraulic/neutronic core instability.” Spec. ¶ 25. The Specification states
that boiling water reactors have a characteristic relation between core flow
and power generation and that “[f]or a fixed amount of control rod
withdrawal from the core, constant rod lines (also called flow control lines
and load lines . . .) can be established.” Spec. ¶ 2. Core flow and power
generation can be depicted on a power/flow operating map, such as those
depicted in Appellant’s Figures 1 and 2, copied below. Spec. ¶ 3.

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Appellant’s Figure 1 is a power/flow map that depicts core thermal power
plotted against core flow and a corresponding Average Power Range
Monitor (“APRM”) flow-biased trip without set down, in accordance with
the prior art. Spec. ¶ 22. Appellant’s Figure 2 is a power/flow map that
depicts core thermal power plotted against core flow and a corresponding
APRM flow-biased trip with set down in accordance with certain
embodiments of Appellant’s invention. Spec. ¶ 23. Figures 1 and 2
generally show that “[i]ncreasing the core flow slowly will increase the
power along [the] constant rod lines” and “[l]oad line limits are established
to satisfy various safety limits including fuel thermal limits.” Spec. ¶ 2; see
Spec. ¶¶ 22–24, Figs. 1–3.
“As power uprates (e.g., up to 120% of the original licensed power)
are implemented, load line limits are raised to realize increased power
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generation at a design (maximum) core flow limit.” Spec. ¶ 3. “However,
core thermal hydraulic stability is aggravated by power uprates and changes
the power/flow operating map in a direction that causes a propensity to
encounter instability” in high power/low core flow conditions. Spec. ¶ 3.
According to the Specification, there are known approaches for the
detection and suppression of instabilities that are suitable for various reactor
types and sizes, depending on the specific plant stability properties. Spec.
¶ 4. Known methods include Oscillation Power Range Monitor (“OPRM”)
hardware and software systems that use oscillation detection algorithms.
Spec. ¶ 4. The Specification states that in some known systems, “an OPRM
system is ‘armed’ (trip-enabled)” such that “[i]f the set point of the OPRM
system is exceeding, indicating the presence of unstable (growing) power
oscillations, an automatic scram or selected rod insertion is initiated to
suppress unstable operation before the oscillations have the potential to
cause fuel damage.” Spec. ¶ 6.
“It is an object of the invention to employ existing licensed stability
methodologies in an [extended operating domain]” by “introducing a set
down of the APRM flow-biased scram line below a certain (e.g., preselected
or predetermined) core flow set point or level.” Spec. ¶ 27. Claim 1,
reproduced below, is illustrative of the claimed subject matter:
1. A method of protecting a core in a nuclear reactor from
fuel damage due to thermal hydraulic instability in an extended
operating domain for an uprated power level, comprising:
operating the nuclear reactor in a permissible operating
domain that is above a first flow control line that corresponds to
an existing power level and below a second flow control line that
corresponds to the uprated power level;
bounding a region of the operating domain with a stability
limit line determined by an algorithm;
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employing OPRM instruments for detecting power
oscillations and thermal hydraulic instability in a first region
above the first flow control line and below the stability limit line;
wherein, when an OPRM setpoint is exceeded, an action
selected from an alarm and a scram signal is generated;
identifying a second region above the stability limit line
and below the second flow control line;
identifying a predetermined core flow setpoint; and
modifying an existing APRM flow-biased scram line
when actual core flow decreases below the predetermined core
flow setpoint, causing an action preventing operation in the
second region, the action selected from the group consisting of
an APRM scram and a selected rod insert.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Eckert US 5,528,639 June 18, 1996
Stirn US 5,141,710 Aug. 25, 1992
Casillas US 2004/0013220 A1 Jan. 22, 2004

REJECTIONS
Claims 1, 5, and 6 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable in view of Eckert and Stirn.
Claims 2–4 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable in view of Eckert, Stirn, and Casillas.
OPINION
Claim 1
The Examiner’s rejection of claim 1 includes a limitation-by-
limitation comparison of claim 1 to Eckert, with additional citation to Stirn
as evidence of known APRM and OPRM diagnostics. Final Act. 2–3;
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accord Ans. 5–6. Among other things, the Examiner states that Eckert
teaches operating a nuclear reactor in a permissible operating domain
depicted by the power/flow map of Eckert’s Figure 1. Final Act. 2–3;
accord Ans. 6 (additionally citing Eckert’s claim 1). As cited by the
Examiner, Eckert’s power/flow map depicts an operating domain that
includes a region between 100% rated power and a “Maximum Normal
Flow” limit representing uprated flow, with scram and alarm setpoints lines
representing additional boundaries of the operating domain. Final Act. 3.
The Examiner also cites Eckert’s disclosures of monitoring operations and
adjusting setpoints during operation. Final Act. 3 (citing Eckert 3:24–35,
3:63–4:10, 5:24–50); Ans. 6.
Appellant acknowledges that Eckert’s power/flow maps depict an
operating domain and that Eckert teaches adjusting alarm and scram
setpoints, but Appellant argues Eckert describes operating and adjusting
setpoints at less than 100% power, below the maximum operating line.
Appeal Br. 4–5. According to Appellant, Eckert’s Figures 2 and 3 show
examples “wherein alarm and scram setpoints are adjusted, i.e., setdown, in
relation to a corresponding set down in power from the maximum operating
line to the partial power operating point 1.” Appeal Br. 5.
Although Eckert does describe adjusting alarm and scram setpoints at
partial power conditions below 100% rated power, we disagree with
Appellant’s suggestion that such disclosures distinguish claim 1. Contrary
to Appellant’s suggestion, nothing limits Eckert to partial power conditions,
and Eckert is clear that its “operating point 1” and the setpoint adjustments
described for operating point 1 are merely an example. Eckert 5:6–65.
Eckert expressly states that the principles of its invention “can be applied as
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needed throughout the entire normal power/flow operating range”
(Eckert 5:11–13). Further, as cited by the Examiner (Ans. 7 (citing Eckert
2:46–55, Fig. 1)), Eckert describes operating a reactor throughout the range
of its operating domain, noting that the “maximum operating level is
normally about 120% of rated power” (Eckert 2:54–55).
Finally, to the extent that Appellant argues to distinguish Eckert on
the basis of claim 1’s recitation of APRM-based trip system (see Appeal
Br. 5–6), we find Appellant’s arguments unpersuasive. As noted by the
Examiner (Ans. 8), in addition to Stirn’s disclosure of OPRM and APRM
systems, Appellant’s Specification evidences that OPRM and APRM
hardware and systems were well known in the prior art (Spec. 4 (describing
OPRM hardware and software as part of a “widely available approach”), 11
(describing an APRM flow-biased trip as part of “[a]nother known stability
solution”)). Eckert describes in general terms use of various known
monitoring parameters to control the operation of a reactor, including
monitoring neutron flux. E.g., Eckert 1:31–45, 1:62–63, 2:46–50 (stating
that conventional power-related nuclear reactor protection systems use
monitored nuclear flux to sense when an increase in power occurs), Fig. 1
(depicting a “Fixed High APRM Flux Scram” line). Among other things,
the Examiner’s determination that Eckert’s teachings would have been
compatible with known OPRM and APRM systems is consistent with the
description of known APRM systems for monitoring neutron flux. See
Spec. ¶ 29 (describing an “APRM neutron flux flow-biased scram”).
Accordingly, we agree with the Examiner that a person of ordinary skill
would have recognized OPRM and APRM-based systems as known options
for implementing Eckert’s teachings.
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Having considered the Examiner’s rejection in view of Appellant’s
arguments and the evidence of record, we sustain the Examiner’s rejection
of claim 1 as being unpatentable in view of the combined teachings of
Eckert and Stirn.
Claims 2–6
For dependent claims 2–6, Appellant relies on the same arguments
addressed above regarding claim 1. Appeal Br. 6–7. Having considered the
Examiner’s rejections in view of Appellant’s arguments and the evidence of
record, for the same reasons discussed supra, we sustain the Examiner’s
rejections of claims 2 and 3 as being unpatentable in view of the combined
teachings of Eckert, Stirn, and Casillas and of claims 4–6 as being
unpatentable in view of the combined teachings of Eckert and Stirn.
CONCLUSION
The Examiner’s rejections are affirmed. More specifically, we affirm
the Examiner’s rejections of claims 1 and 4–6 as being unpatentable in view
of the combined teachings of Eckert and Stirn and claims 2 and 3 as being
unpatentable in view of the combined teachings of Eckert, Stirn, and
Casillas.
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DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 4–6 103 Eckert, Stirn 1, 4–6
2, 3 103 Eckert, Stirn,
Casillas
2, 3

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED