ML18081A919

Explanation & Verification of Computer Program,Wesan,In Support of Evaluation of RCS Considering Subcompartment Pressurization Following LOCA for Units 1 & 2.

ML18081A919
Person / Time
Site:	Salem
Issue date:	01/08/1980
From:	Public Service Enterprise Group
To:
Shared Package
ML18081A918	List: ML18081A917 ML18081A919
References
NUDOCS 8001180309
Download: ML18081A919 (17)

Text

EXPLANATION AND VERIFTCATION OF COMPUTER PROGRAM WE SAN IN SUPPORT OF EVALUATION OF THE REACTOR COOLANT SYSTEM CONSIDERING SUBCOMPARTMENT PRESSURIZATION

. FOLLOWING A LOCA FOR SALEM UNITS 1 AND 2 soo11s@ 3(P9,*

e.

WE SAN

• 1. General WESAN is a computer program written by Westinghouse to perform the

• analysis and evaluation of reactor system equipment support structures.

WESAN performs evaluations for normal, upset, and faulted loading conditions using applicable stress allowables and load combinations as defined in the ASME Code and plant Safety Analysis Report.

2. Application/Capabilities In accomplishing the analysis and evaluation of support structures, WESAN performs the following functions:

(i) Multiplies loads applied to the structure obtained from the systems analysis times previously determined member force influence coefficients to obtain six force components at each end of each member in the support system.

(ii) Solves the appropriate stress interaction equations for all loading conditions and tabulates the maximum stresses for each member. In the case of time history loadings for faulted conditions, a complete support evaluation is performed for each time increment *

• (iii) Tabulates all member force components for each end of each member in the support system. The maximum and minimum for each of the six member force components are pri.nted in addition to the member load set which contributes to the highest interaction ratio.

WESAN may be divided into six sections. They are: (1) input, (2) manipu-

• lation of loads, (3) calculation of member loads, (4) determination of minimum, maximum, and controlling loads, (5) calculation of maximum member stresses and interaction ratios and (6) output.

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The input phase involves the reading of the previously discussed information. Input is read both from punched cards and magnetic tape.

During the load manipulation phase, all input loads are transformed

• • (rotated} from the global coordinate system to a local° coordinate system. Dead weight, pressure, and seismic loads and loads due .to a loss of coolant accident (LOCA} are combined. WESAN combines the loads at every point in time during the LOCA transient considering, at every point, all possible sign combinations of the seismic loads

• Member load~ for ~ach set of combined loads acting on the structure are .

calculated for both ends of each member during the next phase.

Mult.ip_lication of a six by six member force influence array by the six-by~one combi.ned load array or vector yields a six-by-one array containing the member forces and moments. After a member load vector has been calculated, WESAN performs a test to determine if each load is a maximum or minimum load *

• Once the loads on a member have been calculated, WESAN determines the combined stress ratio per *the specifications of the ASME Code Section III, Article XVII, Paragraphs XVII-2213 through XVII-2215 *. Allowable stresses used in the interaction equations and methods of load combination used are in accordance with those given in the applicant's Final Safety Analysis Report.

Support plane loads that act at the intersection of the vertical -

• centerline ~f a primary component and its support are input to WESAN which combines the loads. WESAN is capable of reading deadweight, thermal, pressure, seismic and accident loads. loads due to a loss of coolant*accident are read by WESAN in a time-history form. In addition

• to the loads, WESAN require the following input information:

(1) Orientation of the local coordinate system relative to the

• global coordinate system, (2) yield strength.of material at

• temperature, (3) number of members, (4) member cross section properties and dimensions, (5) member type {i.e. wide flange, pipe, etc.), (6) member influence coefficients, and {7) type of analysis.

(normal, upset, faulted).

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• e Member influence coefficients are forces and moments at each end of each member resulting from unit Fx, Fy, Fz, Mx, My and Mz loads applied to the structure. These are determined in a separate stiffness analysis of the structure.

The WESAN output includes a listing of all the information input to the program and a sumnary of maximum, minimum, and controlling loads and the maximum interaction ratio for each member. The controlling loads are that set of loads which combine to produce the maximum interaction ratios. For the faulted condition, the time of occurrence of the controlling loai:J vector is printed for each member.

3. Theory WESAN is written to perform standard matrix operations, such as multiplication, addition, and subtraction. Also included in the program.

is a subroutine to determine the maximum and minimum values in an array or vector of quantities such as interaction ratios, stresses, and forces *

• The methods used in determining the member loads and interaction ratios will be detailed in the description of the ver.ification problem~

4. Qualification and Verification

a. Quali~ication WESAN was written by Westinghouse to perform the functions des.cribed

• in the application' section. A typical RCS equipment support as described below was selected for WESAN qualification. A successful

• solution of this problem, obtained using the WESAN program, demonstrates that WESAN performs the functio.ns for which .it was designed *

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b~

Verification Problems WESAN is verified in the following section by comparison of computed data with results of hand calculations. The problem chosen represents a typical RCS equipment support structure which would be analyzed

. . by WESAN. Comparison of results obtained by WESAN with the results obtained by hand calculations shows that they are in exact agreement and proves that WESAN provides accurate answers.

• 5. Verification Problem

a. Introduction WESAN was verified by hand calculating the data computed by WESAN for a typical RCS support structure. The loads considered for this verification were deadweight, thermal, pressure, seismic, and DBA forces acting on the support frame structure from the supported

• equipment. These loadings were typical loadings determined from the RCL/Support System analysis. The system analysis OBA output was on tape; WESAN then read these loads from tape. Deadweight, pressure!

thermal, and seismic loads obtained from the system analysis were input to WESAN by punched cards. Member influence coefficients input from punched cards for each end of each structural member were multiplied by the applied support plane forces to obtain member forces. Loads, member properties, and member influence coefficients read into WESAN were printed in the output.

b. Description of Problem The verification problem consisted of a three-legged frame as shown

• in Figure 1. The top *horizontal members serve only as rigid spokes to transfer the support loads from the central mass point of the model to the structural members. Normal, seismic, and accident loads were applied to the structure at that point

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/ u The purpose of this problem was (i) to calculate maximum interaction

• equation ratios for each end of each member of the frame selected for specified structure loadings and member properties, (ii) to determine and tabulate the forces at each end of each member that produce the maximum interaction equation ratios, and (iii) to calculate and

• t~bulate maximum and minimum values of each force component for each

. end of each member. The verification results also include a supplementary summary of interaction equation ratios, corresponding member force components, maximum force components, and minimum force

• components for combined normal, seismic, and OBA loads for each time increment. As the calculations performed by WESAN are similar for .

each member, a single member, 24, was chosen .for verification by hand calculations.

The model selected for this v~rification problem is adequate to verify WESAN because the program is independent of specific structures.

• The program operates on ;Specified input, the correctness of which must be verified separately for its applicability to the

• actual structure.

c. Hand Computations The following procedure was used to calculate member force components for member 24, end 1. Loads applied .to the structure are shown in Table 1. The support structure loads were first combined by the following equation:

~

• where FCj = Combined member force component (Seismicj)2 j = 1 Fx I

• j = 2 j = 3 j = 4 j =5 FY Fz*

Mx My

• .j =6 Mz (Thermal loads are not included for the faulted condition per FSAR requirements.)

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(Note: The purpose of this problem is to show that for a given set ti

• of input forces, correct stresses can be calculated. The combination of seismic and LOCA is handled. generically as a separate issue. As the WESAN user has a choice *o~ methods of load ~ombination, the load combination for each plant analysis will agree with that stated in

• the applicant's Final Safety Analysis Report. The SRSS summation is illustrated in this problem.)

In a faulted evaluation, WESAN systematic~lly varies the signs of the

• seismic support structure load components at. each time increment: a complete support evaluation is then performed for each combination of seismic loads. If the seismic and LOCA load components are of the same sign, that sign is affixed to the radical. If they are of

• opposite signs, the loads are added together absolutely, with no SRSS sumnation.

Member force components for combined dead1-1eight, pressure, seismic,*

and LOCA loads (rotated through a 10°* angle) were calculated by the

• • following equation:

6

= E (M .. ) ( L . ) I 1000 lJ J i = 1, 2, 3, 4, 5, 6 j=l where F1 = member force component i =1 Axial Force i =2 Shear Y Force

/

i =3 Shear Z Force i =4 Torsion i =5 Bending Moment y

=6 Bending Momemt z i

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• Lj = load component acting on support structure j

j j

j

=1

=2

=3

=4 j =5 j = 6 (M;j) =Member Influence Coefficient Matrix (see Table 2)

• Member force components due to support structure OBA loads are shown in Table 3 with the hand calculated values at several time steps. The correlation between WESAN results and hand calculated numbers in Table 3 verifies WESAN's accuracy in the determination of member loads.

I .

The combined axial load and bending interaction ratio is calculated by the following (equations 19, 20, 21 of Paragraph XVII-2215.1 of the ASME Code,Section III):

• (1) fa +

~

cm f by fa (1 *- p-) Fby ey

+

(1 cm fbz f

F~ ) Fbz.

ez

= Interaction Ratio and fa + f by + . f bz (2)

.60Fy Fby r bz = Interaction Ratio or (3) = Interaction Ratio

• (If~ ~ 0.15)

Using the member properties input into WESAN (Table 4), WESAN calculates

• the interaction ratios using the bending, tension. and* compression allowables as defined in the ASME Code Section III, Article XVII-2000.

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For the verification problem, the allowable axial and bending stresses were calculated and substituted into equations (1) and (2). The allowables were calculated per the requirements of XVII-2000 as follows:

{i) Axial *allowables (compression)

• For (Ki/r) < Cc, where . .*

• Fy*= member yield stress (Ki/r) = slenderness ratio calculated from member prop~rties and the fraction of critical buckling to be used per requirements of the applicant's Final Safety Analysis Report. A value of 0.9 was used in this problem.

Axial allowable (tension)

• Ft= .6 Fy 8 of 10

.... ~ .. *- .:. :.. ... *.c:. -... *~- :.:. --. . *.  :..... :.-.. :.. ,_

• • . (ii) Bendin~ Allowables To c.alculate bending allowables, WESAN first checks compact section criteria of Paragraph XVII-2214.1. If the section

• ~

does not satisfy the criteria of XVII-2214.1, WESAN then applies the appropriate allowables from paragraphs XVII-2214.2 to XVII-2214.6 *

• • For the verification problem, fur Z axis b_ending so that Par~graph XVII-2214.2 applied and Paragraph XVII-2214.6 applied for y axis bending so that

• Fby = .6 Fy The combined member loads and bending and axial load allowables were substituted in the verification problem into equations (1) a~d (2). The interaction ratio resulting from hand computations was .499. This is substantially i dent i ca 1 to the ratio of

• 4981 computed by WE SAN. This verified WESAN's ability to compute accurate interaction ratios a11d to choose the maximum interaction ratio for a member.

WESAN computes a combined shear and torsion . ratio in. addition to the combined bending and axial force ratio. The ratios are compared to determine the maximum ratio. In the verification problem, the bending and axial load ratio is larger, as is the case with most support structures. The combined shear and torsion ratio is computed as follows:

• Mx C

(.~Sy) Ix

= Interaction Ratio

• I This ratio is not printed by WESAN unless it is the maximum ratio for the

• member.

6.0 Conclusions

• • This verification of WESAN includes all of the operations performed, specifically:

• • Reading proper normal, seismic, and time history DBA forces Calculation of member forces by multiplying support plane loads by member influence coefficients read in by punched cards

• Calculation of axial and bending and shear and torsion interaction ratios Verification that maximum interaction equation ratios tabulated are

• in fact maximum values Verification that forces listed as maximum or minimum values are in fact* maximum or minimum values.

It has been demonstrated that results from WESAN are substantially identical to results of hand calculation to justify acceptance of the program

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• I FIGURE 1*. Verification Problem Model

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e TABLE l

• 1 LOADS APPLIED TO THE SUPPORT STRUCTURE 2

(ki~s, in-kips}

3 4 5 6

• ~= lx FY Fz Mx .My Mz DEAD . 0.0 -200.0 0.0 a.a 0.0 0.0 THERMAL o.o 50.0 0.0 85.0 o.o 95.0

\~ .. ~;*-~

.RES SURE o.o 1.0.0 0.0 97.0 0.0 47.0 SEISMIC 1 0.0 158.0 0.0 3089.0 0.0 1843 .o SEISMIC 2 0.0 76.0 0.0 2701.0 0.0 3719.0 LOCA 0.0 -379.0 0.0 -1195.0 0.0 -26689.0 a} t = .1130

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TABLE 2

• MEMBER FORCE INFLUENCE COEFFICIENTS FOR 1000 KIP, IN-KIP LOADS AT MODEL MASS POINT MEMBER 24, END l i 1 2 3 4 5 6 j

1 6.o 333.0 0.0 7.24 0.0 .573 2 0.0 - 9.03 0.0 .10 0.0 .06

• 3 4

5.

0.0 o.o 0.0 6.73

.26

-423.0 0.0 0.0 0.0

.102 0.0

-6.37 0.0 0.0 0.0

.166 0.0

-11.8 6 0.0 -719.0 0.0 -4.94 0.0 9.74

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• TABLE 3 COMPARISON OF WESAN OUTPUT WITH HAND CALCULATIONS MEMBER 24 END l OBA FORCE COMPONENTS .

• COMPONENT Fx

. Fy Fz TIME (SEC)

.1130

.* 1130

.1130 HAND CALCULATION

-116.3 1.487 6.595 WESAN OUTPUT

-116.2 1.4

- 6.6 Mx .1130 *0985 .1 .

My .1130 450.9 449.7 Mz .1130 - 2.643 - 2.6 Fx .1330 100.0 100.0 Fy Fz

.1330

.1330 4.230 l.928 4.3 1.9 Mx .1330 .06967 .1 My .1330 154.9 154. l Mz .1330 ~449.l -449.2 Fx .1530 - 32.77 - 32.7 Fy .1530 .3364 .3

• • - - 0.0 Fz .1530 2.429 2.4 Mx .1530 .03575 My .1530 167.4 166.9 Mz .1530 - 18.23 - 18.2 Fx .1730 - 10.01 - 10 .o Fy .1730 - l .127 - 1.2 Fz Mx

.1730

.1730

- 3.097 0.0

- 3.1 0.0 My. .1730 220.2 219.5 Mz .1730 -182. l -182 .1

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• • TABLE 4 MATERIAL AND MEMBER PROPERTIES FOR MEMBER 24 (in~ kip)

• • - A Py_

AZ 24.7 6.4 18.7

• I .

x

• 1y Iz ..

4.41 225.0 928.0 E 29000.

Sy 37.5 sz. 131.0 12.02 Bf T . .780 f

Dw. 12.62 Tw .451 L 106.5

.65

~

Kz .65

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Ry 3.018 Rz *6 .130 cm .85

• • • I.F.

Fyield 1.63 50.0

TABLE 5 Comparison of WESAN Output with Hand Calculations Member 24 Faulted Force Components (kips, in-kips)

• Component; Fx Hand Calculation

• .:205.

WESAN Output

-204.5

• . FY Fz Mx 3.6 8.4

.2

~

3.6 8.4

.2 562. 560.3

~

My Mz 163. 163 .

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