Ex Parte Trosman et al

Patent Trial and Appeal Board

Feb 19, 2013

10748174 (P.T.A.B. Feb. 19, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte LUKAS TROSMAN, CARY L. KUNZ,
RUSSELL E. STACHOWSKI, RUSSELL M. FAWCETT,
SHINGO FUJIMAKI, and DAISUKE GOTO
____________________

Appeal 2010-009839
Application 10/748,174
Technology Center 2800
____________________

Before: TERRY J. OWENS, JENNIFER D. BAHR, and
SCOTT E. KAMHOLZ, Administrative Patent Judges.

BAHR, Administrative Patent Judge.

DECISION ON APPEAL

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STATEMENT OF THE CASE
Lukas Trosman et al. (Appellants) appeal under 35 U.S.C. § 134 from
the Examiner’s decision rejecting claims 24, 26-29, and 31-33. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM-IN-PART.
The Claimed Subject Matter
Claim 24, reproduced below, is illustrative of the claimed subject
matter.
24. A fuel bundle for a boiling water reactor,
comprising:
a generally square, hollow tube having four
sides which are configured as sides of the bundle,
a pair of circular-shaped water passages
located adjacent to a longitudinal centerline of the
tube so as to extend centrally through the tube, the
pair of water passages supported by one or more
rod supports,
a plurality of fuel rods arranged in a 10x10
matrix and including full-length rods and part-
length rods, the part-length rods further
comprising:
a first part-length rod group including two
subsets in a mirror-image relationship along the
centerline between the two water passages, each
subset further comprising three part-length fuel
rods in a triangular orientation with one rod of the
subset closer to the longitudinal centerline between
the two water passages than the other two rods of
the subset and directly adjacent to the other two
rods of the subset, and
a second part-length rod group including
four pairs of part-length rods, each part-length rod
pair centrally located in the outermost row or
column of the l0x10 matrix adjacent a
corresponding one of the four sides of the tube.
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Evidence
The Examiner relied on the following evidence in rejecting the claims
on appeal:
Ueda
Johansson
Orii
US 5,068,082
US 5,229,068
US 6,735,267 B2
Nov. 26, 1991
Jul. 20, 1993
May 11, 2004

Rejections
Appellants request our review of the following rejections under 35
U.S.C. § 103(a):
I. claims 24 and 26-29 as unpatentable over Orii, Ueda, and
Johansson; and
II. claims 31-33 as unpatentable over Orii and Johansson.

OPINION
Rejection I
Appellants state that “[c]laims 24 and 26-29 rise and fall together.”
App. Br. 10. Thus, we select claim 24 to decide the appeal with respect to
this group of claims.
The Examiner found that Orii (fig. 15) discloses a fuel bundle as
called for in claim 24, “except that the [part-length] rod subsets in a mirror-
image [along] the center line between the two water passages are pairs rather
than triplets.” Ans. 3-4.
The Examiner found that Ueda (fig. 19) teaches providing 3-rod sub-
groups of part-length rods adjacent to a water passage. Ans. 4. The
Examiner also found that Ueda teaches including part-length rods in a fuel
assembly in order to modulate shut-down. Ans. 6; see Ueda, col. 12, ll. 61-
66.
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The Examiner additionally found that Johansson teaches numerous
advantages to using part-length rods, including improved cold shut-down
margin, provision of voids overlying the part-length rods that have increased
vapor fraction resulting in full length rods adjacent the voids having
increased liquid fraction, and reduction in pressure drop in the upper two
phase region resulting in increased stability. Ans. 5-6; see Johansson, col. 2,
ll. 3-15.
Relying on the combined teachings of Orii, Ueda, and Johansson, the
Examiner reasoned that the inclusion of a third part-length rod in each of the
two part-length rod subsets of Orii (fig. 15) is no more than the duplication
of parts with predictable and intended effects (Ans. 4), and that the skilled
artisan desiring to duplicate the advantageous effect of the rods in the 2-rod
subsets “in the interest of modulating the shut-down margin would be
motivated to provide a 3-rod subset” (Ans. 5). The Examiner also
determined that the number and arrangement of part-length rods is “a matter
of optimization within prior art conditions or through routine
experimentation.” Ans. 6. The Examiner thus concluded it would have been
obvious to provide 3-rod subsets of part-length rods in Orii’s fuel bundle
configuration (fig. 15) as taught by Ueda, and applying the power
modulation teachings of Johansson, to achieve the benefits discussed in Orii,
Ueda, and Johansson, “particularly an improved shutdown margin, as part of
an optimization of a known technology.” Id.
Appellants contend that Orii’s specific fuel rod patterns were
discovered through the rigorous application of conditional equations, and
that further modification of Orii’s rod patterns would require significant
calculations and additional experimentation to ensure Orii’s conditional
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equations remain satisfied. App. Br. 13-14. Along those same lines,
Appellants argue that the combination of Orii and Ueda proposed by the
Examiner would destroy the intended function of Orii, and that the addition
of Johansson with Orii and Ueda would cause Orii to be inoperable for its
intended purpose. App. Br. 18. Appellants assert that “the Examiner
disregards the extent of experimentation described by Orii.” Id. According
to Appellants, “such casual manipulation of Orii’s rigorously defined part-
length rod orientations, using only the general teachings of Ueda, renders the
Orii reference inoperable for its intended purpose” and the proposed
“combination of Johansson with Orii and Ueda would violate the conditional
Equations of Orii.” App. Br. 18-19.
The conditional equations, or “Inequalities,” as characterized by the
Examiner (Ans. 9), alluded to by Appellants are Equations 1, 11, 3, 4, 15,
and 6 set forth by Orii at column 3, lines 25-43. We agree with the
Examiner that these conditions, expressed as inequalities, leave a substantial
degree of latitude for compliance (see Ans. 9), and we reject Appellants’
argument that application of these inequalities would require significant
calculation and additional experimentation to ensure satisfaction of the
expressed conditions. In fact, the Examiner performed the calculations to
show that the Orii configuration modified as proposed by the Examiner
satisfies the mathematical conditions set forth by Orii. See Final Rej. 7
(showing that by setting Awr/Ach=0.125 and Lp/Lf=0.5, both of which fall
within the acceptable hatched area of figure Orii’s 16, Equations 3, 15, and 6
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can be satisfied for n=141). Appellants do not challenge the Examiner’s
calculations, which appear to be correct.
In light of the above, the Examiner has persuasively discredited
Appellants’ bald assertions that the proposed modification of Orii would
require substantial calculations or experimentation, destroy the intended
purpose of Orii, or render Orii inoperable for its intended purpose.
Moreover, as noted by Appellants (App. Br. 14), Orii discloses that
“[t]he short length fuel rods may be arranged differently from the
arrangement of FIG. 15 if the short length fuel rods are arranged both in the
positions in the outermost tier and in the positions adjacent to the water rods,
or arranged only in the outermost tier.” Orii, col. 14, ll. 7-11. The modified
configuration proposed by the Examiner comprises the short length fuel rods
both in the outermost tier and in the positions adjacent to the water rods, as
illustrated in Orii’s figure 15, and also comprises the short length fuel rods
in two additional locations adjacent to the water rods. Thus, the
modification proposed by the Examiner appears to fall within the scope of
permissible variations of Orii’s figure 15 configuration.
Appellants’ Reply Brief focuses on the distinction between part-length
rods and fuel rods having “interposed” members (i.e., portions in which
enrichment of the fissile nuclide is significantly reduced or does not exist at
all) as taught by Ueda. See, e.g., Reply Br. 3-4; see also App. Br. 16; Ueda,
col. 3, ll. 32-35; id. at col. 8, ll. 28-48; id. at col. 12, ll. 57-58. Appellants
argue that the combination of Orii, Ueda, and Johansson does not teach or
suggest the pattern of “part-length” fuel rods, as distinguished from full-

1 Adding the two part-length rods as proposed by the Examiner to the twelve
part-length rods shown in Orii’s figure 15 configuration yields n=14, which
falls within the range dictated by Orii’s Equation 11.
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length fuel rods having “interposed” members, called for in claim 24. Reply
Br. 7.
Appellants’ line of argument with respect to the asserted distinction
between part-length fuel rods and full-length fuel rods having “interposed”
members, and thus a shorter effective length, is unavailing. Orii’s discussion
of effective fuel rod length (col. 3, ll. 39-42) may suggest that Orii’s
teachings of short-length fuel rods (col. 1, ll. 36-37), or “second fuel rods
having a length shorter than a length of the first fuel rod” (col. 3, ll. 16-17),
may encompass either full-length fuel rods having interposed members, as
taught by Ueda, or fuel rods having a shorter axial length. However, Ueda’s
teachings with respect to fuel rods having a partial effective fuel area
explicitly extend both to full-length fuel rods having interposed members
and to fuel rods having a length shorter than that of the other (i.e., full-
length) fuel rods. Ueda, Abstract; col. 3, ll. 48-51. Further, in discussing the
numerous advantages of “part length rod construction” (col. 2, ll. 3-4),
Johansson clearly refers to “less than full length” fuel rods that “extend
upwardly to and toward the upper tie plate, but terminate short of the upper
tie plate” and define “[b]etween the point of part length fuel rod termination
and the upper tie plate” a vent volume “in the upper two phase region of the
fuel bundle” (col. 1, ll. 60-67). Thus, the combined teachings of Orii, Ueda,
and Johansson would have prompted a person of ordinary skill in the art to
provide part-length rods having a shorter axial length than the other rods in
the fuel bundle configuration of Orii to attain the many advantages cited by
Orii, Ueda, and Johansson.
Appellants also make much of the distinctions between Ueda’s figure
19 configuration and the claimed configuration. App. Br. 16. In particular,
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Appellants point out that Ueda’s figure 19 configuration involves an 8x8
matrix, not a 10x10 matrix, and comprises a cruciform-shaped water
passage, not a pair of circular-shaped water passages. Id. Appellants
additionally point out that in Ueda’s configuration, the 3-rod subgroups are
four 3-rod subgroups, not two subsets in a mirror-image relationship
between the two water passages. Id. According to Appellants, these
distinctions are so significant that “Ueda provides almost no guidance for a
person of ordinary skill in the art to modify FIG. 15 of Orii.” Id. at 16-17.
These asserted distinctions between Ueda’s figure 19 configuration
and the claimed configuration do not apprise us of error in the Examiner’s
rejection. Ueda does not limit its teachings of the advantages of part-length
rods to a particular rod matrix configuration. Moreover, the Examiner does
not seek to bodily incorporate the figure 19 embodiment of Ueda into Orii,
but rather relies on Ueda only for its teaching to provide 3-rod subsets
adjacent to a water passage. Appellants’ argument appears to attack Orii and
Ueda individually, rather than the combination of Ueda and Johansson with
Orii proposed by the Examiner. Nonobviousness cannot be established by
attacking the references individually when the rejection is predicated upon a
combination of prior art disclosures. See In re Merck & Co. Inc., 800 F.2d
1091, 1097 (Fed. Cir. 1986).
For the above reasons, Appellants fail to apprise us of error in the
Examiner’s rejection of claim 24 as unpatentable over Orii, Ueda, and
Johansson. Thus, we sustain the rejection of claim 24 and of claims 26-29.
Rejection II
Claim 31 and its dependent claims 32 and 33 are directed to a fuel
bundle in the form of a 10x10 matrix including a first rod group comprising
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two pairs of part-length rods arranged on either side of a corner of a square
water passage and a second group comprising two pairs of part-length rods
and at least two non-paired part-length rods each located in a corresponding
outermost row or column of the matrix.
The Examiner relied on the configuration of Orii’s figure 20 as the
starting point for the rejection of claims 31-33. Ans. 6-7. This configuration
comprises a short length fuel rod located adjacent each side of a square
water passage and a pair of short length fuel rods located in the center of
each of the outermost rows and columns of the matrix. Relying on
Johansson’s teaching that the addition of part length rods lowers the pressure
drop, thereby improving critical power, the Examiner reasoned that “[t]he
number and arrangement of part-length rods is therefore likewise a matter of
optimization within prior art conditions or through routine experimentation”
and determined it would have been obvious to modify Orii’s arrangement
“to have either two (claim 31) or three (claim 33) non-paired [part-length]
rods as part of an optimization of a known technology.” Ans. 7-8. The
Examiner added that “[t]he beneficial effects of using part-length rods are
known and predictable, and the skilled artisan would be motivated to
optimize these effects by producing part-length rod arrangements tailored to
the neutronic environment in any given part of the reactor core. Id.
It is not apparent, and the Examiner has not adequately explained,
why a person of ordinary skill in the art would have been led to the
particular configuration called for in claims 31-33 through routine
optimization in accordance with the teachings of Orii and Johansson. The
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Examiner’s assertion that “making the aforementioned additional pairs[2], of
part-length rods into non-paired rods is no more than the omission of an
element and its function where the element is not desired” (Ans. 8) is
unavailing, as the Examiner does not provide any evidence or technical
reasoning establishing that the function of the omitted part-length rod of the
rod pairs of Orii’s configuration might not be desired. To the contrary, Orii
discloses that “the short length fuel rods may be arranged differently from
the arrangement of FIG. 18 if the short length fuel rods are arranged both in
the positions in the outermost tier and in the positions adjacent to the water
rods, or arranged only in the outermost tier, and further the fuel assembly
1J shown in FIG. 20 may be acceptable.”3 Orii, col. 15, ll. 24-30 (emphasis
added). Thus, omission of any of the short length fuel rods arranged in the
outermost tier, as ostensibly proposed by the Examiner, would seemingly be
contrary to the teachings of Orii. See App. Br. 22.
The Examiner therefore failed to establish a prima facie case that the
subject matter of claims 31-33 would have been obvious. We do not sustain
the rejection.
DECISION
The Examiner’s decision rejecting claims 24, 26-29, and 31-33 is
affirmed as to claims 24 and 26-29, but is reversed as to claims 31-33.

2 See Ans. 7, finding that “Fig. 20 depicts an additional two pairs of part-
length rods rather than two non-paired part-length rods as recited in claim
31.”
3 The only distinction between the fuel assembly of Orii’s figure 20 and that
of Orii’s figure 18 is that figure 18 depicts a circular water passage and
figure 20 depicts a square water passage.
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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-IN-PART

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