ML20090A212
| ML20090A212 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 07/09/1984 |
| From: | Horin W BISHOP, COOK, PURCELL & REYNOLDS, TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML20090A206 | List: |
| References | |
| NUDOCS 8407110299 | |
| Download: ML20090A212 (11) | |
Text
..
1;;iM p
![h Y' 9, 1984 UNITED OTATES Or AMERICA r
NUCLEAR REGULATORY COMMISSI'M J'L 10 P2:27 J
BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
Docket Nos. 50-445 and TEXAS UTILITIES ELECTRIC
)
)
)
(Application for (Comanche Peak Steam Electric
)
Operating Licenses)
Station, Units 1 and 2)
)
APPLICANTS' MOTION FOR
SUMMARY
DISPOSITION REGARDING ALLEGATIONS CONCERNING CONSIDERATION OF FORCE DISTRIBUTION IN AXIAL RESTRAINTS Pursuant to 10 C.F.R.
$2.749, Texas Utilities Electric Company, eti al.
(" Applicants") hereby move the Atomic Safety and Licensing Board for summary disposition regarding the allegations concerning the consideration of force distribution in axial restraints.
As demonstrated in the accompanying affidavit and statement of material facts, there is no genuine issue of fact to be heard regarding these matters.
Applicants urge the Board to so find, and to conclude that Applicants are entitled to a favorable decision as a matter of law, and to dismiss the issue from the proceeding.
1 8407110299 840709 PDR ADOCK 05000445 Q
PDR y
- _ _ _ _ ~,, - - _
--.._.,m, y
i l.
I.
BACKGROUND t-In its Memorandum sad Order (Guality Assurance fer Design),
t
' - ---Mcsusa De cember,2C, l']C3. t " Memorandum:mid 'Or*:: "),.th: 00 rd addressed certain allegations raised by CASE regarding pipe r
i i
support designs.
The Board did not address this particular i
allegation.
The Board indicated, however, that it believed
[
t additional information should be received regarding CASE's
{
allegations and, accordingly, suggested that Applicants proposed t
'a plan to address CASE's allegations.
Memorandum and Order at i
72-75.
[
i L
In response to the Board's suggestion, Applicants proposed
[
t on February 3, 1984, a plan that would provide the Board with the information necessary to satisfy the concerns presented in its Memorandum and Order.
This motion concerns Plan Item 15,1 which f
i i
responds to two sets of allegations made by CASE.
CASE alleges t
[
that Applicants' have failed to adequately consider the effects i
i of welded attachments (trunnions) to trapeze-type supports.
CASE l
argues that Applicants ignore the rotational resistance of the L
)
i l
restraint which would have a significant adverse affect on the f
piping analysis and support loads.
(CASE Proposed Findings, I
i 1
Applicants' Plan to Respond to Memorandum and Order (Quality
(
Assurance for Design), February 3, 1984 (" Applicants' i
Plan").
The accompanying aff:1svit provides Applicants' response to Item 15 of Applicants' plan.
That task, as stated in thu plan, is to j
i provide evidence of how the design has accounted for the torsional resistance of f
i.
axial restraints.
This evidence will be
[
generated through the performance of p
[
analyses.
j l
i r
_ _ _. ~ _ _ _ _ _., _, -, _.. _, ~ _,. _,, _ _ _. _, _ _ _..., _. _ _. _, _, _ _ _. _.
3-Section XVII.)
Further, CASE alleges that Applicants' assessment of the distribution of loada in avtal raatraints utilizing lug
--nine metachments.
CAM:--a rgnwhat ApnJ i na nt s ' analvses of this type of support fails to consider certain factors which affect the loads in the support, piping and attached lugs.
(CASE Proposed Findings,Section XII.)
Applicants addressed each of 2
these allegations in their Proposed Findings at 55-57 and 64-65.
In addition, Applicants also addressed these assertions in their Reply to CASE's Proposed Findings 3 at 36-37 and 41-43.
Applicants set forth below their analyses performed in response to Item 15 of Applicants' plan.
II.
APPLICANTS MOTION FOR
SUMMARY
DISPOSITION A.
General Applicants have previously discussed the legal requirements applicable to motions for summary disposition in their " Motion for Summary Disposition of Certain CASE Allegations Regarding AWS and ASME Code Provisions Relating to Welding", filed April 25, 1984 at 5-8.
Accordingly, we incorporate that discussion herein by reference.
2 Applicants' Proposed Findings of Fact in the Form of a Partial Initial Decision, August 5, 1993.
3 Applicants' Reply to CASE's Proposed Findings of Fact and Conclusions of Law (Walsh/Doyle Allegations), September 6,~
1983.
. Further, the Board recently addressed the standards applic.2ble to the dispuslLiun of the motions submitted as part of W
7-7p~plidazits~'; Plait; 11. IL:, Juha 20, 1034', Mar. orc:Tder. and Ordar
-r-(Written-Filing Decision # 1: Some AWS/ASME Issues).
There the Board noted that the standard applicable to the resolution of Applicants' motions will be consistent with the Board's intention of disposing of these outstanding issues in written pleadings.
Specifically, the Board indicated that whether a hearing is necessary to resolve these matters will be decided on a determination of whether sufficient information has been presented to enable the Board to make a reasoned decision.
Accordingly, this standard should be applied to the instant motion.
We believe, however, that the matters set forth below demonstrate nonetheless that Applicants wculd be entitled to summary disposition in accordance with the standards set forth in 10 C.F.R. $2.749.
B.
The Outstanding Issues Regarding Applicants' Consideration of Force Distribution in Axial Restraints Should be Summarily Dismissed 1.
CASE's allegations CASE alleges that Applicants' design approach for axial restraints fails to consider certain loads transmitted to the support and pipe.
CASE's allegation concerns two types of axial restraints.
The first type is configured as a trapeze with welded attachments to the pipe and support (trunnion) which distributes the axial load to the support.
The second type of l
5-support distributes the axial load to a frame by lugs welded to the pipe.
(Affidavit at 2-3.)
These allegations ara addressed i
- uvarutelj'in 7.IF attached affidavit.c 2.
Welded attachments to trapezes (trunnions) l As noted above, CASE alleges that Applicants' design methodology for analyzing these supports ignores the rotational resistance of the restraint which results in failure to account for certain effects on the piping and supports.
Applicants' design approach for these supports is to model the support as a single support acting in the axial direction.
(Affidavit at 3.)
As demonstrated in the attached affidavit, Applicants' modelling technique is appropriate.
The modelling technique urged by CASE would be very conservative and not necessarily a more realistic modelling technique.
Nevertheless, Applicants evaluated the significance of the effects CASE alleges should be considered by reanalyzing several piping stress problems i
utilizing the modelling assumptions CASE would have Applicants employ.
(Affidavit at 3-4.)
These analyses demonstrated that Applicants' assumption of i
excluding the rotational restraint of the trapeze support from the analysis has virtually no effect on pipe stresses.
(Affidavit at 4-5).
With respect to the effect of CASE's modelling assumption on the supports, Applicants' analyses demonstrated that changes in loads on the supports on the reanalyzed stress problems occur
. only with respect to the trapeze supports themselves.
This effect is expected in that modelling the rotational conctraint of
- the-cupport' will produce - nn additional loadren ear'. side cf the --.
r
- r-trapeze not previously analyzed.
However, as discussed below, these additional loads do not exceed applicable allowables.
(Affidavit at 5-6.)
To fully' assess the effects of modelling the rotational constraint of the support Applicants evaluated every; Unit 1 and common double trunnion support employed at Comanche Peak for these effects.
Those analyses demonstrated that the total loads imposed on each side of the trapeze supports would be acceptable, i.e.,
in no case were Code allowables exceeded, when the additional loads were factored into the support design.4 (Affidavit at 6-8.)
In sum, CASE's assertion that Applicants' modelling assumptions for these supports is incorrect is unfounded.
No basis exists to conclude that this practice is not appropriate or that another analytical model (including that CASE argues should t
i l
4 To assess these additional loads Applicants employed allowables permitted by Section NF-3231.1 of the ASME Code for evaluation of self-limiting loads resulting from the constraint of free-end displacement.
This approach is appropriate given the self-limiting nature of the load imposed from the torsional restraint of the pipe.
That load is self-limiting in that the rotation which produced the increased load will not exceed that which would occur if there had been no rotational constraint.
In all cases the
" free" rotation of the pipe (computed in the absence of rotational restraint) at the location of the support is very small.
(Affidavit at 7.)
. l be used) would demonstrate that the support loads and pipe stresses are not within applicable code allowables. (Affidavit at r
0.).
3.
Lug-type restraints CASE presents two concerns regarding the analysis of axial restraints employing lugs attached to the pipe.
First, CASE L
argues that installation of the lugs on the pipe will not achieve perfect symmetry and, therefore, distribution of the load according to the stiffness of the support structure is invalid.
Second, CASE argues that the angularity of the pipe (due to thermal expansion at the point of the support) wi.11 preclude contact of all lugs.
Thus, the structure should be analyzed assuming a single point contact at the extreme point of the support.
(CASE Proposed Findings at XII-6.)
With respect to CASE's first concern, Applicants do not disagree that perfection in construction may not be achieved.
However, it is neither necessary nor reasonable to expect that l
the four lugs can be installed in a perfect circumferential plane with zero tolerance.
We expect, however, the lugs to be l
installed within reasonable limits and, indeed, have found this i
to be the case.
Applicants' inspection of 29 supports which have lugs welded to the pipe disclosed that the maximum deviation, j
i.e., difference in distance between any of the lugs and the frame, on their respective sides of the frame, exceeded 1/16".
i l
This instance involved a deviation of 5/64 inch on one side of I
l l
P'
the support.
In addition, in most instances at least two lugs on either side of the frame were found to be of equal distance frcm
-thedrame.-~ A: a. rc= ult of thi=- ti. gcetien, it.:.:y tr -rencluded i-e that the stresses Which may occur in the pipe, lug or f'rame as a result of differential engagement of the lugs will be localized.
These potential local deformations would be self-limiting and readily redistribute the load to other lugs. Only one other lug Eneed be engaged to fully resist the entire load which may be imposed.
(Affidavit at 10-11.)
With respect to CASE's assertion that the loads should be assumed to be taken by the lugs furthest from the support anchors, Applicants recognize that if such an assumption is made, the frame deflection can, in fact, be larger than. initially
~
\\
assumed in that-the moment lever arm between the frame embedmonts and the point of load application would be longer.
- However, both frame deflection and rotation of the pipe will act to close the gap to opposite or adjacent lugs. (Affidavit at 12-13.)
Applicants investigated the two scenarios which could occur in such. instances, viz., the lugs being stronger than the frame l
(and thus greater frame deflection) and the frame being stronger f'
than the. lugs (inducing small deformations in the lug until other lugs are engaged). For the case in which. the frames are weaker j
than the lugs, Applicants performed a study of idealized frames loaded axially using the four lug arrangement.
Two cases were analyzed for this assessment which reflect the situations in V
Which the deflection of the frame would be small and the I-
r i
i
_9_
cituation in which the deflection of the frame could approach Applicants' 1/16" deflection criterion.
Thee: frame reprc=ent the ranga of-sti f fnesses -which -may occur in: the fiald and.
- k '.' s.
t-r-
provide evidence of the ability to deflect to permit engagement of additional lugs.
For the first case, Applicants determined i
that the deflection of the frame even with the maximum additional deflection created by the assumption of initial engagement by the outer most lug indicates that the Applicants deflection guideline would not be exceeded.
In the second case, it was found that a I
L deflection slightly exceeding l' 16" may be required to bring a
/
cecond lug in contact with the frame.
Any excess loads would be celf-limiting and thus when the load is shared by the second lug the deflection no longer increases for a given load. (Affidavit ct 13-14.)
To assess the condition in which the frame is stronger than the lug and, thus, lug localized yielding may occur, Applicants cnalyzed the effect of the maximum localized yielding in the lug cnd the pipe surface which could occur to bring the additional lugs in contact with the frame.
This analysis was performed ucing a non-linear finite element technique and the computer program NASTRAN.
The result of this analyses show that minimal plastic strains, entirely localized at the surface of the pipe i
and the welds permit a 1/16" deflection from the lugs with no cdverse consequence to the lugs.
With respect to the stresses on the pipe, Applicants' analysis demonstrates that they would also
~
ba acceptable.
(Affidavit at 14-15
, Attachment 2).
- -.,,, ~
-,-n.
w
III.
CONCLUSION For the foregoing reasons, Applicants' motion for summary 1
disposition should be granted.
Respectfully submitted, bh
.C 1 Nicholas S.
Reynolds William A.
Horin BISHOP, LIBERMAN, COOK, PURCELL & REYNOLDS 1200 Seventeenth Street, N.W.
Washington, D.C.
20036 (202) 857-9817 Counsel for Applicanta July 9,, 1984 O