BARC/1999/E/037

1N0000258 |33"ro

DEVELOPMENT OF A SOFTWARE FORTHE ASME CODE QUALIFICATION OFCLASS-1 NUCLEAR PIPING SYSTEMS

byRajesh Mishra, C. Umashankar, R. S. Soni, H. S. Kushwaha

andV. Venkat Raj

Health, Safety & Environment Group

1999

3 1 - 11

BARC/1999/E/037

« GOVERNMENT OF INDIAg ATOMIC ENERGY COMMISSION

1

DEVELOPMENT OF A SOFTWARE FOR

THE ASME CODE QUALIFICATION OF

CLASS-I NUCLEAR PIPING SYSTEMS

byRajeshMishra, C. Umashankar, R.S. Soni, H.S. Kushwaha

and

V.VenkatRaj

Health, Safely & Environment Group

BHABHA ATOMIC RESEARCH CENTREMUMBAI, INDIA

1999

BARC/1999/E/037

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BARC External

Technical Report

BARC/1999/E/037

Development of a software for the ASME Code qualification ofclass-1 nuclear piping systems

33 p., 4 figs., 3 tabs., ill.

Rajesh Mishra; C. Umashankar; R.S. Soni; H.S. Kushwaha;V.VenkatRaj

Health, Safety and Environment Group, Bhabha AtomicResearch Centre, Mumbai

Bhabha Atomic Research Centre, Mumbai - 400 085

Reactor Safety Division,BARC, Mumbai

Department of Atomic Energy

Government

Contd... (ii)-i-

30 Date of submission: October 1999

31 Publication/Issue date: November 1999

40 Publisher/Distributor: Head, Library and Information Services Division,

Bhabha Atomic Research Centre, Mumbai

42 Form of distribution: Hard copy

50 Language of text: English

51 Language ofsummary: English

52 No. of references: 6 reft.

53 Gives data on:

6 0 Abstract: In nuclear industry, the designer often comes across the requirements of Class-1 pipingsystems which need to be qualified for various normal and abnormal loading conditions. In order tohave quick design changes and the design reviews at various stages of design, it is quite helpful if adedicated software is available for the qualification of Class-1 piping systems. BARC has alreadypurchased a piping analysis software CAESAR-II and has used it for the Life Extension of HeavyWater Plant, Kota. CAESAR-II facilitates the qualification of Class-2 and Class-3 piping systemsamong others. However, the present version of CAESAR-II does not have the capability to performstress checks for the ASME Class-1 nuclear piping systems. With this requirement in mind and theprohibitive costs of commercially available softwares for the Class-1 piping analyses, it was decided todevelop a separate software for this class of piping in such a way that the input and output details ofthe piping from the CAESAR-II software can be made use of. This report principally contains thedetails regarding development of a software for codal qualification of Class-1 nuclear piping as perASME Code Section-in, NB-3600. The entire work was carried out in three phases. The first phaseconsisted of development of the routines for reading the output files obtained from the CAESAR-Hsoftware, and converting them into required format for further processing. In this phase, the node-wise informations available from the CAESAR-II output file were converted into element-wiseinformations. The second phase was to develop a general subroutine for reading the various inputparameters such as diameter, wall thickness, corrosion allowance, bend radius and also to recognizethe bend elements based on the bend radius, directly from the input file of CAESER-II software. Thethird phase was regarding the incorporation of the required steps for performing the ASME Codalchecks as per NB-3600 for Class-1 piping systems. The developed software has been tested analyticallyfor verification of the results and has been found to be performing satisfactorily.

70 Keywords/Descriptors: HEAVY WATER PLANTS; NUCLEAR INDUSTRY; PIPELINES;VALIDATION; C CODES; LOSS OF COOLANT; PRESSURE DEPENDENCE; STRESSES;STRESS ANALYSIS; REACTOR SAFETY; FLOWSHEETS; TESTING

71 INIS Subject Category: E2200

99 Supplementary elements:

•it-

ABSTRACT

In nuclear industry, the designer often comes across the requirements ofClass-1 piping systems which need to be qualified for various normal and abnormalloading conditions. In order to have quick design changes and the design reviews atvarious stages of design, it is quite helpful if a dedicated software is available for thequalification of Class-1 piping systems. BARC has already purchased a piping analysissoftware CAESAR-II and has used it for the Life Extension of Heavy Water Plant, Kota.CAESAR-II facilitates the qualification of Class-2 and Class-3 piping systems amongothers. However, the present version of CAESAR-II does not have the capability toperform stress checks for the ASME Class-1 nuclear piping systems. With thisrequirement in mind and the prohibitive costs of commercially available softwares for theClass-1 piping analyses, it was decided to develop a separate software for this class ofpiping in such a way that the input and output details of the piping from the CAESAR-IIsoftware can be made use of. This report principally contains the details regardingdevelopment of a software for codal qualification of Class-1 nuclear piping as per ASMECode Section-Ill, NB-3600.

The entire work was carried out in three phases. The first phase consistedof development of the routines for reading the output files obtained from theCAESAR-II software, and converting them into required format for further processing.In this phase, the node-wise informations available from the CAESAR-II output file wereconverted into element-wise informations. The second phase was to develop a generalsubroutine for reading the various input parameters such as diameter, wall thickness,corrosion allowance, bend radius and also to recognize the bend elements based on thebend radius, directly from the input file of CAESER-II software.

The third phase was regarding the incorporation of the required steps forperforming the ASME Codal checks as per NB-3600 for Class-1 piping systems. Thedeveloped software has been tested analytically for verification of the results and hasbeen found to be performing satisfactorily.

CONTENTS

Page nos.1.0 Introduction 32.0 Features of Existing Piping Analysis Software CAESAR-n 43.0 Need for a Separate Software for Class-1 Piping Qualification 44.0 Development of Post-Processor for Qualification of Class-1 Piping

4.1 Static Analysis 54.2 Dynamic Analysis (Inertial) 54.3 Missing Mass Correction 6

5.0 Procedure of Qualification for Class-1 Piping5.1 General Requirements (As per NB-3651) 65.2 Consideration of Design Conditions (As per NB-3652) 75.3 Consideration of Level-A Service Limits (As per NB-3653) 85.4 Consideration of Level-B Service Limits (As per NB-3654) 115.5 Consideration of Level-C Service Limits (As per NB-3655) 125.6 Consideration of Level-D Service Limits (As per NB-3656) 12

5.6.1 As per Old Code 135.6.2 As per New Code( 1998 Edition) 13

6.0 Choice of FORTRAN Language for Development of the Software 137.0 Organisation of the Program

7.1Phase-I 147.2 Phase-II 157.3Phase-m 15

8.0 Testing 169.0 Conclusions 1610.0 References 17

Tables 18Figures 20Appendix-A: Sample Formatted Tables for Various Files 24

1.0 Introduction

Piping forms an important segment of any industrial plant and acts aslifeline for these plants. The importance of piping systems can be realized from the factthat in many plants, the cost of piping approaches about 50-60% of the total plant cost.In the nuclear industry, piping systems play a major role of carrying various radioactiveliquids from one equipment to the other. The very fact that these systems carryradioactive liquids, calls for utmost care in their design and analysis in order to safeguardthe plant personnel as well as the public at large. The most crucial piping components in anuclear plant are those which form the part of primary pressure boundary, the failure ofwhich may result in direct release of fission products into the containment atmosphere.Therefore, the primary pressure boundary piping is assigned the highest safety class i.e.,the Safety Class-1 for its design and qualification. The design of such piping is usuallycarried out by using the ASME Code, Section-in, Subsection-NB. It is required toqualify the Class-1 piping not only for all the normal conditions, i.e. dead weight,pressure, temperature etc. but also for the abnormal events like earthquake, Loss ofCoolant Accident (LOCA) etc.

While a number of softwares are available in the market for the pipinganalysis, there are only a few commercially available softwares which have thecapability of performing the Class-1 piping qualification, viz. PS-CAEPIPE. However,the cost of such softwares is abnormally high and unjustifiable.

BARC has already purchased a piping analysis software CAESAR-II andhas used it for the Life Extension of Heavy Water Plant, Kota. The software CAESAR-H,has the capabilities for the qualification of piping systems designed as per ANSI B31.1,B31.3 and various other codes including ASME Section-in, Subsections NC (for Class-2piping) & ND (for Class-3 piping). This software has the main limitation that it does nothave the capability for qualification of Class-1 piping. Upgrading this software wasconsidered as an economical means of fulfilling the need for Class-1 piping qualification.

With an aim to develop an indigenous capability to fulfill theaforementioned requirement, it was decided to develop a software which should be ableto interact with the input and output files of CEASAR-II for the generation of requiredinputs for further processing. Thus, a separate software has been developed for thequalification of Class-1 piping which uses the information obtained from static anddynamic files of CAESAR-II software and also picks up the required input data forqualification of the piping as per the requirements of ASME Section-in, Div.l,Subsection-NB.

2.0 Features of Existing Piping Analysis Software CAESAR-II

CAESAR-H is a PC-based computer program (Ref.l). This softwarepackage is an engineering tool used in the mechanical design and analysis of pipingsystems. The CAESAR-II user creates a model of the piping system using simple straightbeam elements and curved pipe elements and defines the loading conditions imposed onthe system. With this input, CAESAR-H produces results in the form of deflections,loads, and stresses throughout the system. Additionally, CAESAR-H also compares theseresults with their codal limits and gives the stress output by expressing induced stress inthe form of percentage of allowable values.

CAESAR-II capabilities include the modeling of piping systems,connected fittings, equipment, various supports etc., and analyzing them for the fullrange of static and dynamic loads which may be imposed on the system. Therefore,CAESAR-H is not only a good tool for new design, but it is also quite valuable introubleshooting or redesigning the existing systems. Other capabilities of this softwareinclude the codal stress checks, analyses for water hammer and relief valve dischargeloads, calculations of stresses as per WRC-107 & WRC-297, equipment related checks,fatigue leakage calculations, analysis of buried piping, etc. In addition to these, it has astrong database of various pipe sizes, materials, valves, flanges, bellows, hangers, etc.

3.0 Need for a Separate Software for Class-1 Piping Qualification

In nuclear industry, the designer often comes across the requirements ofClass-1 piping systems which need to be qualified for various normal and abnormalloading conditions. In order to have quick design changes and the design reviews atvarious stages of design, it is quite helpful if a dedicated software is available for thequalification of Class-1 piping systems. With this requirement in mind and the prohibitivecosts of commercially available softwares for the Class-1 piping analyses, it was decidedto develop a separate software for this class of piping in such a way that the input andoutput details of the piping from the CAESAR-D software can be made use of. Theexisting modules of CAES AR-II software could not be accessed for this developmentsince the source code is not available. Moreover, the Class-2 and Class-3 piping analysiscapabilities of CAESAR-II could not be explored for the qualification of Class-1 pipingon account of the following reasons:

(a) The procedure for qualification of piping systems for Class-1 piping is completelydifferent from the procedure adopted for Class-2 and Class-3 piping.

(b) The equations used in the code NB (Class-1) and the load combination checkssuggested in it, are different from those required to be carried out for codes NC(Class-2) & ND (Class-3).

(c) Stress Intensification Factors (SDFs) used in the equations are different for NB (Class-1) and NC (Class-2), ND (CIass-3) codes. The primary plus secondary stress check forClass-1 piping uses Q & C2 stress indices whereas for the Class-2 and Class-3pipings, i is used as the SIF.

(d) For Service Levels-A & B conditions, there is no elasto-plastic discontinuity analysisprocedure defined in codes NC (Class-2) & ND (Class-3) whereas these are welldefined in NB (Class-!) code.

4.0 Development of Post-Processor for Qualification of Class-1 Piping

Nuclear pipings are subjected to internal pressure, temperature and weightunder normal operating conditions. However, they are also designed to withstand upsetconditions like Operating basis Earthquake(OBE) and emergency conditions like, Safeshutdown Earthquake(SSE). All the loadings are categorized into following servicelevels, as defined in ASME section-in, Sub-section : NCA (Ref.2), and pipings have to bequalified accordingly:

A) Design Condition : Design pressure, weight loading and OBEB) Service level -A : Operating pressure, temperatureC) Service level -B : Pressure, temperature, OBED) Service level -C : Pressure, weight loading, SSEE) Service level -D : Pressure, weight loading, SSE, Loss Of Coolant Accident

(LOCA)

Analysis of piping systems can be divided into the following three stages :

4.1 Static Analysis - This is carried out to evaluate the response of piping due to weight,internal pressure and thermal loading.

4.2 Dynamic Analysis (Inertial) - This is carried out to evaluate the response due toOBE and SSE. The earthquake loading is applied in two horizontal directions, i.e. North-South, East-West and Vertical direction utilizing the respective site spectra or floorresponse spectra.

The responses due to various modes are combined using any one of themodal combination methods viz., Grouping method, 10% Square Root Sum of Squaresmethod (SRSS), Double Sum method (DSRSS), Absolute method & SRSS method.Spatial combinations are carried out using SRSS method. The response due to Seismic

Anchor Movement (SAM) is also calculated and added with the inertial response in anabsolute manner.

4.3 Missing Mass Correction - In order to account for the missing mass in variousdirections, which has not participated upto the floor ZPA (Zero Period Acceleration)frequency or upto the cut-off frequency in the seismic inertial analysis, the rigid bodymode response is estimated by pseudostatic method, which uses the appropriateacceleration value either corresponding to the floor ZPA or corresponding to the cut-offfrequency.

5.0 Procedure for Qualification of Class-1 Piping

Analysis of piping system should be carried out for the following stresses:

(i) Primary stress check: This is carried out to evaluate the stresses due to dead weight &pressure loading,

(ii) Primary plus Secondary stress check : This is carried out to evaluate the stresses onthe piping system due to thermal expansion, thermal anchor movements and due toearthquake loading,

(iii) Peak stress check : This analysis is carried out to find out peak stress intensity rangewhich is utilised for carrying out fatigue check on the system.

The various conditions to be satisfied in the analysis under various servicelevels are as follows:

(i) Design condition : primary stress intensity limit to be satisfied(ii) Level-A service limits: primary + secondary stress intensity range check(iii) Level-B service limits : primary stress check and primary + secondary stress

intensity range check(iv) Level-C service limits : primary stress check(v) Level-D service limits: primary stress check

5.1 General Requirements (As per NB-3651)

To validate a design in accordance with these rules, it is necessary toperform several piping analyses in accordance with the requirements of NB-3672 and touse the moments and forces obtained from these analyses as required in NB-3650. After

evaluation of the forces and moments, the stresses are calculated and it is ensured thatthey are within the allowable values, as prescribed by ASME, Sec.HI, Div.l, Subsection-NB for Class-1 Components. Following nomenclature has been adopted while performingthe stress checks:

Mi,j = Moment about i-th axis due to j-th loading (for static case)

(Mi,n)k = Moment about i-th axis for n-th loading, with excitation in k-th direction (fordynamic case).

Where,

i = x for x-direction= y for x-direction= z for x-direction

j = gr for gravity loading= pr + th for pressure and thermal loading= ps for pseudostatic rigid body response

n = OBE for operating Basis Earthquake loading= SSE for Safe Shutdown Earthquake loading

k = N-S for Horizontal North-South direction= E-W for Horizontal East-west direction= VER for Vertical direction

5.2 Consideration of Design Conditions (As per NB-3652)

As per NB-3652, the primary stress intensity limit is satisfied if therequirement of Equation (9) is met. The primary stress is any normal stress or a shearstress developed by an imposed loading which is necessary to satisfy the laws ofequilibrium of external and internal forces and moments. The basic characteristic of aprimary stress is that it is not self-limiting.

P * Do Do * Mi+ B2* <n.5Sm (9)

2*t 2*1

where,

Bl, B2 = Primary stress indices for the specific product under investigation(NB-3680)

P - Design pressure, Kgf/mm2

Do = outside diameter of pipe, mm (NB-3683)t = nominal wall thickness of product, mm (NB3683)I a Moment of Inertia (mm4)

Mi = resultant moment due to a combination of Design MechanicalLoads, Kgf-mm. All Design Mechanical loads and combinationsthereof shall be provided in the Design specification. In thecombination of loads, all directional moment components inthe same direction shall be combined before determining theresultant moment (i.e., resultant moments from different loadsets shall not be used in calculating the moment Mi). If themethod of analysis for earthquake or other dynamic loads is such thatonly magnitudes without relative algebraic signs are obtained, themost conservative combination shall be assumed.

Here, Mi can be defined as follows:

X N.s = SQRT((( MX,OBE) N-S) 2+ ((Mx.ps) N.s)2)

X B.W = SQRT((( MX,OBE) E-W) 2 + ((Mx,re) E-W)2)

X VER = SQRT((( MX,OBE) VER) 2 + ((Mx,re) VER)2)

MX,OBE= SQRT((X N . s ) 2 + (XE-w V + ( X V E R f)

M X = I Mx.gr I + MX, OBE

Similarly, My and Mz shall be calculated.

Then,

Mi = SQRT( ( Mx)2 + (My)2 + (Mz)2)

5.3 Consideration of Service Level A Limits (As per NB-3653)

Level-A is Normal operating condition for which satisfaction of primaryplus secondary stress intensity range is required as per NB-3653.1. Secondary stress is anormal stress or a shear stress developed by the constraint of adjacent material or by self-constraint of the structure. The basic character of a secondary stress is that it is self-limiting.

This calculation is based upon the effect of changes which occur inmechanical or thermal loading which take place as the system goes from one load set,

such as pressure, temperature, moment, and force loading, to any other load set whichfollows it in time. It is the range of pressure, temperature, and moment between two loadsets which is to be used in the calculations. For example, one of the load sets to beincluded is that corresponding to zero pressure, zero moment, and room temperature.Equation (10) shall be satisfied for all pairs of load sets:

Po* Do Do* MiSn m Cl* + C2* £ 3Sm (10)

2 *t 2*1

where,

C1.C2 = Secondary stress indices for the specific component underinvestigation (NB-3680)

Do, t, I, Sm = as defined for Equation (9)

Po = Range of Service pressure, Kgf / mm2

Mi = Resultant range of moment which occurs when the system goesfrom one service load set to another, Kgf-mm. Service loadsand combinations thereof shall be provided in the Designspecification. In the combination of moments from load sets, alldirectional moments components in the same direction shall becombined before determining the resultant moment (i.e. resultantmoments from different load sets shall not be used in calculatingthe moment range Mi). Weight effects need not be considered indetermining the loading range since they are non-cyclic incharacter. If the method of analysis is such that only magnitudeswithout relative algebraic signs are obtained, the mostconservative combination shall be assumed. If a combinationincludes reversing dynamic loads, Mi shall be either:

1) The resultant range of moment due to the combination ofall loads considering one-half the range of the reversingdynamic loads; or

2) The resultant range of moment due to the full range of thereversing dynamic loads alone, whichever is greater.

In case of Class-1 nuclear piping systems, the loadings under ServiceLevel A include pressure, weight and thermal loads only.

Thus, Mi can be defined as follows:

A = Mx.pr + tf,B=C=

Mi =SQRT( A 2 + B 2 + C2)

If the above equation (10) cannot be satisfied for all pairs of load sets, analternative approach, i.e. simplified elastic-plastic discontinuity analysis can be adoptedas given in NB 3653.6 which is as follows:

Only those pairs of load sets which do not satisfy Equation (10) need tobe considered. First Equation (12) shall be satisfied.

Do* MiC2 * £ 3Sm (12)

2*1

C2, Do, I = as defined in Eqns . (9), (10).

Mi = Resultant moment due to thermal expansion and thermal anchormovements only.

Then, satisfy Equation (13):

Po*Do Do* MiSn = Cl* + C2 * £ 3Sm (13)

2 *t 2*1

Mi = Resultant moment due to loads other than thermal bending and thermal expansionstresses.

10

5.4 Consideration of Service Level B Limits (As per NB-3654)

Level-B is Upset condition for which the procedures for analyzingService loadings for which Level-B service limits are designated, are the same as thosegiven in NB-3653 for Level-A service limits.

Equation (9) should be satisfied as follows:

P*Do Do* Mi+ B2* £ min(L8Sm,1.5Sy) —(9)

2* t 2*1

where,

Sy = Yield Stress at Service temp.

P = Pressure which shall be > 1.1 Pa

Pa (Allowable pressure)= (2 Sm t)/( Do - 2yt ) where, y = 0.4

All other variables are as defined earlier.

The primary plus secondary stress intensity range for each pair of load setsis checked as per equation (10) where,

Po* Do Do* MiSn = Cl* + C2 * £ 3Sm (10)

2 *t 2*1

All parameters are same as defined above.

A= !Mx,pr+th I + Mx, OBE (Mx, OBE as defined under design condition)

B= IMy,pr+th I + My, OBE (My, OBE similar to Mx, OBE)

C = I Mz, pr+th I + Mz, OBE (Mz, OBE similar to Mx, OBE)

11

M u =SQRT( A 2 + B 2 + C 2 )

Mu = SQRT( (2* Mx, OBE)2 +(2*My^BE)2 +(2* Mz, OBE) 2)

Mi = max. {My, Mi,2}

If the above equation (10) cannot be satisfied for all pairs of load sets, analternative approach, i.e. simplified elastic-plastic discontinuity analysis can be adoptedas given in NB-3653.6 which is described above under Service Level-A condition.

5.5 Consideration of Service Level C Limits (As per NB-3655)

Service Level C represents Emergency condition. For service loadingsfor which Level C limits are designated which do not include reversing dynamic loads orhave reversing dynamic loads combined with .nonreversing dynamic loads, the conditionof equation (9) of NB-3652 shall be satisfied as follows:

P * Do Do * MiB ,* + B 2 * £ min (2.25 Sin, 1.8 Sy) (9)

2* t 2 * 1

where,

P = Coincident pressure which is > 1.5 Pa

(All other variables are as defined earlier.)

Mi is as defined under design condition, except that it is computed from SSEmoments, in place of OBE moments.

5.6 Consideration of Service Level D Limits (As per NB-3656)

Service Level D represents Faulted condition. For service loadings forwhich Level D service limits are designated which do not include reversing dynamicloads or have reversing dynamic loads combined with nonreversing dynamic loads,equation (9) shall be satisfied as follows:

12

5.6.1 As Per Old Code

P * Do Do * MiB,* + B2* £ min(3Sm,2Sy) (9)

2*t 2*1

The permissible pressure shall not exceed 2.0 times the pressure Pa.

5.6.2 As Per New Code (1998 Edition)

In the new code, apart from the criteria for reversing dynamic loads thatare not required to combined with non reversing dynamic loads code has permitted to goupto 4.5 Sm value. Apart from this kind of loading, the criteria defined above should befollowed. The stress due to weight and inertial loading due to reversing dynamic loads incombination with the Level D coincident pressure shall not exceed the following:

P * Do Do * Me- + B 2* S 4.5 Sm (9)

2*t 2 * 1

where,Me = the amplitude of the resultant moment due to inertia] loading from

earthquake, other reversing type dynamic events and weight.

6.0 Choice of FORTRAN Language for Development of the Software

FORTRAN (FORMULA TRANSLATION) is the oldest, but still one ofthe most widely used, computer programming languages scientific and engineeringapplications (Ref.4). Its continued success is not only due to its power and versatility indealing with computationally intensive problems and the availability of a wide range ofspecialized mathematical and statistical library programs, but also due to its efficiencyand rapid program execution.

Introduced by IBM in the late 1950's, FORTRAN has gone through anumber of revisions, with FORTRAN-IV being the first standardized version issued in1966, by American National Standards Institute (ANSI). The version (FORTRAN 77) ismore compatible with the principles of structured programming and various other featuressuch as the improved capabilities in manipulating non-numeric data and in processingexternal files. A newer version (FORTRAN 90) with significant upgradation is also

13

available in the market. Here, the software development work has been carried out usingMicrosoft FORTRAN (Refs,5&6).

7.0 Organisation of the Program

A flowchart detailing the various steps required for the softwaredevelopment is shown in Fig 1. The work was carried out in the following three phases:

a) Phase -1 : Development of module for reading the required parameters from theoutput of CAESAR-H, basically the moments for both static anddynamic load cases.

b) Phase • II : Development of module for reading the required parameters from theinput sheet of CAESAR-II, like diameter, wall thickness, corrosionallowance, bend radius and pressure.

c) Phase - III: Development of modules for carrying out calculations as perASME Code Section III, Subsection NB, for various service levelsand for checking the results as per the code specified limits and todisplay the results in presentable formats.

7.1 Phase-I

Phase-I, deals with reading the results from the CAESAR-H softwareoutput neutral files. A sample dynamic output sheet obtained from CAESAR-H is shownas Table A-l in Appendix A.

The main aim is to pick up the moments from the output files ofCAESAR-II. For picking up of the values from the format of the neutral files, the workwould have been simple if there is no random variation in the CAESAR-H output. Butthis was not the case, there were variations, in the formatting of the outputs obtained fromCAESAR-II. Thus, the whole work was becoming more and more challenging andinteresting.

Phase-I work involved the development of two small modules for readingthe "STATIC" & "DYNAMIC" outputs from the CAESAR-U and subsequently to bewritten in intermediate files. The working and reliability of the programs have been

14

checked for various real life problems. A sample intermediate file obtained from thedeveloped program is attached as Table A-2 in Appendix A.

7.2 Phase-II

Phase-H deals with the picking up of the required element parametersfrom the input sheet,, such as the diameter, wall thickness, corrosion allowance, bendradius and pressure. The aim was to incorporate element-wise data in the final outputsheet and also to specify the type, whether straight pipe or bend, corresponding to theelement number. The CAESAR-H input neutral file provides only node-wise data andalso adds complications further with variations in format, in each and every page. Hence,significant effort was required to pick-up the required input data, node-wise and toconvert them into element-wise, with due recognition for element types. A sample inputneutral file obtained from CAESAR-II is shown in the attached Table A-3 in Appendix A.

Another requirement was to discard those elements for which a 'RIGIDWEIGHT' was specified in input sheet (Since CAESAR-II output files omits results forsuch elements). This required special logic to be incorporated in the software, whilereading the input neutral files to recognize the rigid elements and discard them. The finalpart of phase-II was to obtain the read data in a required format in an intermediate file, sothat it can be used as and when required in the main program in Phase-ID (Softwarewhich is evolved for "ASME CODAL CHECK" for class-I piping systems as per NB-3600). These picked-up values are to be utilized for satisfying equations 9 and 10 asdescribed above, as per the requirements of various service levels. A sample intermediatefile generated by developed program with the aforementioned aim in mind, is attachedas Table A-4 in Appendix A.

7.3 Phase-Ill

This phase utilizes the intermediate input & output files generated with thehelp of software modules developed under Phase-I and Phase-II. Phase-Hi, is the finalpart of this program. The main aim of this phase is the qualification of Class-1 pipingfor various load cases, as per ASME^code NB-3600 as described in para 5.0 above.

A sample output file generated by the developed software (afterperforming various calculations as per the requirements of NB-3600) is shown as TableA-5 (Design condition and Level-D service-level) & Table A-6 (for service levels A, B &C) which are given in Appendix-A. These output sheets also show the final results incomparison with the permissible limits specified by the ASME code.

15

8.0 Testing

A typical real-life plant problem has been solved using the developedsoftware and the comparison of results obtained from developed software to that obtainedanalytically is included in this report. The piping layout as shown in Fig. 2 is connectedwith three process towers. Various supporting arrangements i.e. anchors, directionalrestraints and hangers on this layout is shown in Fig. 3. Mathematical model developedusing piping analysis software CAESAR-H is shown in Fig. 4.

The results were obtained as per the requirements for the different load conditionsusing Equation (9) and Equation (10) using the developed software. The results obtainedfrom developed software for a few typical locations (both bend and straight pipelocations) for various service levels were checked analytically as well and thecomparative results are shown in tabular forms in Tables 1-3. As evident from thesetables, the results obtained from the developed software are found to be in excellentagreement with the analytical ones, thus ensuring that the developed software is capableof performing the required ASME code qualification for Class-1 nuclear piping systems.

9.0 Conclusions

A software for Class-1 piping system qualification has been developed andtested successfully. This software incorporates following capabilities to facilitate the user:

1. The software picks-up the output forces directly from the output neutral files ofCAESAR-II.

2. The software picks-up the required input parameters from CAESAR-U input neutralfile directly.

3. The software has demonstrated capability for qualifying Class-1 piping for variousservice levels as per ASME Section-Ill Subsection NCA load combinations.

4. A few practical test problems were solved using the software developed. The resultsobtained from the software agree well with the analytical results.

16

10.0 References

1. Piping Analysis Software CAESAR-D, Version 3.23, COADE Inc. Houston, Texas,USA

2. ASME Boiler and Pressure Vessel Code, Section-Ill, Div. 1, Sub-section NCA, 1998

3. ASME Boiler and Pressure Vessel Code, Sectiori-III, Div. 1, Sub-section NB, 1998

4. Microsoft Fortran, Reference guide. Version 5.5

5. Fortran 77 by Schaum Series, McGraw Hill Publications

6. Computer Programming in Fortran 77 by V. Rajaraman

17

TABLE 1: Comparison of Results obtained from the Software with the Analytical Resultsfor Test Problem (Figs.2-4) (Design condition Eq. 9 (Ref.3))

Node no.

109

50

Type

Bend

Straight Pipe

Contents

Resultant Moment(Kgf-mm)

Induced Stresses(Kgf/mm2)

Resultant Moment(Kgf-mm)

Induced Stresses(Kgf/mm2)

Analytical

0.38743E7

2.7623

0.73169E7

7.2596

Fromsoftware

0.38743E7

2.760

0.7316917

7.2623

TABLE 2 : Comparison of Results obtained from the Software with the Analytical Resultsfor Test Problem (Figs.2-4)

Service Level

DesignCondition

(eq. 9)

Level - A(eq. 10)

Level - B(eq. 10)

Level - C(eq. 9)

Node No.(Element

type)10

(StraightPipe)

10(Straight

Pipe)

10(Straight

Pipe)

10(Straight

Pipe)

Contents

Resultant Moment(Kgf-mm)

Induced Stresses(Kgf/mm2)

Resultant Moment(Kgf-mm)

Induced Stresses(Kgf/mm2)

Resultant moment(Kgf-mm)

Induced Stresses(Kgf/rrlm2)

Resultant Moment(Kgf-mm)

Induced Stresses(Kgf/mm2)

Analytical

1.70019E9

4.647206

0.01132E9

0.0112

3.38745E9

9.26255

2.05627E9

5.5245

Fromsoftware

1.7006E9

4.648

0.01129E9

0.011

3.3878E9

9.263

2.0549E9

5.521

18

TABLE 3 : Comparison of Results obtained from the Software with the Analytical Resultsfor Test Problem (Figs.2-4)

Service Level

DesignCondition

(eq.9)Level - A(eq. 10)

Level - B(eq. 10)

Level - C(eq-9)

Level -D(eq. 9)

Node No.(Element

type)119

(Bend)

119(Bend)

119(Bend)

119(Bend)

119(Bend)

Contents

Induced Stresses(Kgf/mm2)

Induced Stresses(Kgf/mm2)

Induced Stresses(Kgf/mm2)

Induced Stresses(Kgf/mm2)

Induced Stresses(Kgf/mm2)

Analytical

2.0617

0.0031

2.6385

1.8651

2.0617

Fromsoftware

2.062

0.003

2.64

1.864

2.062

19

c(

CAESER-II INPUTNEUTRAL FILE

*CEASER-II OUTPUT

NEUTRAL FILE

y-Ly-i

READ GEOMETRICAL,DATA 7

READ FORCESAND MOMENTS

( CODAL QUALIFICATION OF CLASS-I PIPING SYSTEM

CHECK PRESSURE DESIGN (NB 3640, EQ.3)U - |PDo/2(SE+Py)l+A

CHECK FORt •

DESIGN CONDITION (Wt+Pr+OBE)(NB 3652. EQ.9)

CHECK<

FOR

''1

NO

(Pr+Th)fNB 3653.k + Ca*$?-<3 S«

EQ.IO;

- ^ SERVICE LEVEL - A ^ -(Pr+TH)

IF CHECK FOR-—_ CREEP REQUIRED ^*-

CHECK

YES

FOR CREEPCj^-«

(NBJ3 S

3653.m

EQ.IO)

SERVICE LEVEL B EQ.9 CHECKR PDo . R M 1.8 S,

YES

USE RESULTANT MOMENT (Mo)DUE TO (TH-»-OBE)LOADINGS

SERVICE LEVEL - B(TH+OBE) NB 3654. EQ.10

(TH+0BE)>(2 OBE)

NO

USE RESULTANT MOMENT (Mo)DUE TO 20BE LOADINGS

PDo Mo

1SERVICE LEVEL-C (Wt+Pr+SSE)(NB 3655, EQ. 9)

r | ^ S Sm

AS PER NEW CODES . - 4 . 5 Sm

CHECK AS PER NB 3656, EQ.9

SERVICE LEVEL - 0(Wt+Pr+SSE+LOCA)F CHECK REOD. AS

PER OLD CODEAS PER OLD CODE

.5 S»

FIL£NAME:RM1

FIG. 1: FLOW CHART UTILISED FOR THE SOFTWARE DEVELOPMENT

20

1617TE

ro

PROCESSTOWERS

NOZZLE

\

PPELME

FLANGED VALVE

FIG. 2: 3-D SCHEMATIC LAYOUT OF THE TEST PROBLEM

1617TESYMBOLS

- ORECTIONM.4E8TRAMT

FIG. 3: TEST PROBLEM - PIPING SUPPORT DETAILS

1617TE1180

=IG. 4; MATHEMATICAL MODEL OF THE TEST PROBLEM

Appendix-A

CAESAR II Ver 3.23 Job: N22INLicensed To: BARCLOCAL FORCE REPORT, Forces on Elements

(OCC)SHOCK CASE # 1

Date NOV 27,1998 Time 18:25 Page: 1ID 15257

NODE — •

TOTALS..MODE MAX

100

108

108

109

1

1

1

Forces(KgtJ

.. Fa Fb

.. Fa/Mode Fb/Mode

13 *

11 **

x(i) •** i :

13

n

x(i) i :

13

n

X(l) 1 }

13

9

39

37

Ml) 2 ;

39

37

Ml) 2 !

39

37

((1) 2 5

39

37

FcFc/Mode

12

8

5(1)

12

8

S{1)

11

8

5(1)

11

7

. HC

MaMa /Mode

48776

41057

1 X(l)

48776

41057

1 X(l)

48776

41057

1 X(l)

22004

16878

jmencs \ i\.y . nui

MbMb/Mode

19342

14524

1 X(l)

18405

14792

1 X(l)

18405

14792

1 X(l)

14477

12877

a i

MeMe/Mode

38663

36185

1 X(l)

30895

28744

1 X(l)

30895

28744

1 X(l)

35484

29629

109

110

13

9

1)

10

7

1)

1 1

1 J

39

36

Ml)

39

36

C(l)

1 }

1 >

10

7

Ml)

13

11

C(l)

22004

16878

1 X(l)

2761

1721

2 Z(l)

14477

12877

1 X(l)

7602

6862

1 X(l)

35484

29629

1 X(l)

22505

17849

2 Z(l)

* The largest dynamic force that occured during the event** The largest modal component

*** largest modal component due to mode (1),loading direction (X)iload component number (1)

TABLE A-1:A typical dynamic output sheet obtained from piping analysissoftware CEASAR-II for the layout shown in Fig.2

25

ELEMENTNo.

1

2

3

4

5

6

7

8

9

10

11

NODENo.

100108

108109

109110

110115

115118

118119

119120

120130

130138

138139

139140

Mx

-.23800E+04.23800E+04

-.23800E+04.10321E+05

-.10321E+05.12450E+05

-.12450E+05.12450E+05

-.12450E+05.12450E+05

-.12450E+05-.11419E+05

-11419E+05-.26618E+05

.26618E+05-.26618E+05

.26667E+05-.26667E+05

-26667E+05.33380E+04

-.33380E+04-.13940E+04

MOMENT (Kgf-mm)My Mz M*

.53968E+05 .11944E+05 .55325E+05

. 54258E+05 -.12050E+-05 .55631E+05

.54258E+05 -.12050E+05 .55631E+05

.34133E+05 .71200E+04 .36363E+05

.34133E+05 -.71200E+04 .36363E+05

.23380E+04 -.19810E+04 .12822E+05

.23380E+04 -.19810E+04 .12822E+05

.14602E+05 .18480E+04 .19278E+05

.14602E+05 -.18480E+04 .19278E+05

.26732E+05 .16560E+04 .29535E+05

.11197E+05 .24330E+05 .29535E+05

.12646E+05 -.30550E+05 .34980E+05

.12646E+05 .30550E+05 .34980E+05

.10566E+05 -.33980E+04 .28839E+05

.33980E+04 -.10566E+05 .28839E+05

.69031E+05 .88240E+04 .74509E+05

.69031E+05 -.86760E+04 .74510E+05

.60250E+05 .85540E+04 .66441E+05

.85540E+04 -.60250E+05 .66441E+05

.87800E+03 .14939E+05 .15333E+05

.87800E+03 -.14939E+05 .15333E+05

.11256E+05 -.23613E+05 .26196E+05

* M = sqrt (Mx * Mx + My * My + Mz * Mz}

TABLE A-2: A typical sheet showing intermediate file generatedby the module of the developed software from theCEASAR-II static output neutral file for problemshown in Pig.2.

26

C A E S A R I I VERS 3.23 JOBNAME:N22IN NOV 271998 6:19pm Page 1Licensed To: BARC . ID: 15257

PIPE DATA

From 100 To 110 DY= -950.000 mm.PIPE

Dia= 168.275 mm. Wall= 10.972 mm. Insul= 40.000 mm. Cor= 6.0000 mm.GENERAL

Tl= 25 C T2= 21 C Pl= .2040 Kg./sq.mm P2= .1620 Kg./sq.mmMat= (l)LOW CARBON STEEL E= 20741 Kg./sq.mm v = .292Density= .0080 kg./cu.cm. Insul= .0001 kg./cu.cm.Fluid= .00021280 kg./cu.cm.

BEND at "TO" endRadius= 75.0.000 mm. (user) Bend Angle= 90.000 Angle/Node @1= 45.00 109Angle/Node @2= .00 108

RESTRAINTSNode 100 ANC

SIF's & TEE'SNode 110 <No Type Specified> Sif(in)= 2.373 Sif(out)= 2.373

ALLOWABLE STRESSESB31.1 (1992) Sc= 12 Kg./sq.mm Shl= 12 Kg./sq.mm Sh2= 12 Kg./sq.m

m

From 110 To 115 DZ= -1000.000 mm.

From 115 To 120 DZ= -1110.000 mm.BEND at "TO" end

Radius= 750.000 mm. (user) Bend Angle= 90.000 Angle/Node @1= 45.00 119Angle/Node @2= .00 118

SIF's & TEE'SNode 120 <No Type Specified> Sif(in)= 2.373 Sif(out)= 2.373

From 120 To 130 DX= -1818.440 mm. DY= -704.110 mm.RESTRAINTS

Node 130 Y K= 3832 Kg./mm

From 130 To 140 DX= -779.560 mm. DY= -296.890 mm.BEND at "TO" end

Radius= 750.000 mm. (user) Bend Angle= 90.000 Angle/Node @1= 45.00 139Angle/Node ®2= .00 138

SIF's & TEE'SNode 140 <No Type Specified> Sif(in)= 2.373 Sif(out)= 2.373

TABLE A-3:Input neutral file generated from piping analysis software CAESAR-IIfor the problem shown in Fig.2

27

ELEMENTNo.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

NODENo.

100108

108109

109110

110115

115118

118119

119120

120130

130138

138139

139140

140143

143146

146147

147150

150160

190200

O.D.

(ram)

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

168.27168.27

THICK-NESS(mm)

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10;9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

10.9710.97

7,117.11

CORROSIONALLOWANCE

(mm)

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

*6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

6.006.00

.00

.00

BENDRADIUS(ram)

750.00750.00

750.00750.00

750.00750.00

.00

.00

750.00750.00

750.00750.00

750.00750.00

.00

.00

750.00750.00

750.00750.00

750.00750.00

.00

.00

.00

.00

.00

.00

.00

.00

.00

.00

.00

.00

PRESS.(DESIGN)

(kgf/sq.mm)

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

.204

-204.204

.204

.204

.204

.204

.204

.204

ELE.TYPE

bendbend

bendbend

bendbend

strstr

bendbend

bendbend

bendbend

strstr

bendbend

bendbend

bendbend

strstr

strstr

strstr

strstr

strstr

strstr

TABLE A-4: A typical intermediate input file generated for the problem shownin Fig.2, by the module of the developed software from the inputneutral file (TABLE A-3)

28

Stress checks for Design condition & Service Level D using code equation (9)

ELE.NO.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

NODENO.

100108108109109110110115115118118119119120120130130138138139139140140143143146146147147150

ELE.TYPE

bendbendbendbendbendbendstrstrbendbendbendbendbendbendstrstrbendbendbendbendbendbendstrstrstrstrstrstrstrstr

INDUCEDDESIGNkgf /tm2

2.422.382.382.182.181.882.082.051.851.921.922.062.062.172.362.632.462.392.391.841.841.822.042.142.142.282.282.152.152.81

.20Sm

.20Sm,20Sm.18Sm.18Sm.16Sm.17Sm.17Sm.15Sm.16Sm.16Sra.17Sm.17Sm.18Sm.20Sm.22Sm.21Sm.20Sm.20Sm.15Sm,15Sm.15Sm.17Sm.18Sm.18Sm.19Sm.19Sm.18Sm.18Sm.23Sm

STRESSLEVEL DKgf/mm2

2.422.382.382.182.181.882.092.061.851.921.922.062.062.172.362.632.462.392.391.841.841.822.042.142.142.282.282.152.152.81

.20Sm

. 20Sm

.20Sra

.18Sm

.18Sm

.16Sm

.17Sm

.17Sm

.15Sm

.16Sra.

.16Sm,17Sm,17Sm.18Sm,20Sm.22Sra.21Sm,20Sm.20Sm,15Sm.15Sm.15Sm,17Sm.18Sra.18Sm.19Sm.19Sm.18Sm.18Sm.23Sm

ALLOWABLE STRESS LIMITSDESIGNkgf/mm2

18.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.018.0

1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm1.5Sm

LEVEL DKgf/mm2

36.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.036.0

3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sro3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3 Sin3Sm3Sm3Sm3Sm3Sm

TABLE A-5: A sample output sheet generated by the developed software for theTest Problem (Figs.2-4)

29

Stress checks for Service Levels A(eq.10),B(eq.10) & C(eq.9) using code

ELE.No.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

NODENo.

100108108109109110110115115118118119119120120130130138138139139140140143143146146147147150

ELE.TYPE

bendbendbendbendbendbendstrstrbendbendbendbendbendbendstrstrbendbendbendbendbendbendstrstrstrstrstrstrstrstr

LEVEL C

kgf/mm22.082.082.081.881.881.631.851.921.691.811.811.861.861.792.012.462.282.192.191.651.651.771.982.112.112.202.201.761.762.68

.17Sm

.17Sm

.17Sm

.16Sm

.16Sm

.14Sm

.15Sm

.16Sm

.14Sm

.15Sm

.15Sm

.16Sm

.16Sm

.15Sm

.17Sm

.21Sm

.19Sm

.18Sm

.18Sm

.14Sm

.14Sm

.15Sm

.17Sm

.18Sm

.18Sm

. 18Sm

.18Sm

.15Sm

.15Sm

.22Sm

INDUCED-STRESSLEVEL A

Kgf/mm2.004.004.004.004.004.004.002.002.004.003.003.003.003.003.002.003.005.005.005.003.003.004.003.004.004.008.008.013.013.017

.OOSiti

.OOSrn-OOSm.OOSro.OOSm. OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm.OOSm

ALLOWABLELEVEL B

kgf/mm23.743.593.593.073.072.422.041.912.212.212.212.642.642.812.282.212.692.692.692.482.482.161.881.841.842.082.082.382.382.55

.31Sm

.30Sm

.3 0Sm

.26Sm

.26Sm

.20Sm

.17Sm

.16Sm

.18Sm

.18Sm

.18Sm,22Sm.22Sm.23Sm.19Sm.18Sm.22Sm.22Sm.22Sm.21Sm.21Sm.18Sm.16Sm.15Sm.15Sm.17Sm-17Sm.20Sm.20Sm.21Sm

C

2.25Sm2.25Sm2.25Sm2.2 5Sm2.2 5Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.2 5Sm2.2 5Sm2.2 5Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.25Sm2 .25Sm2.25Sm2.25Sm2.25Sm2.25Sm2.2 5Sm

LIMIT:A

3 Sin3Sm3Sm3Sm3 Sin3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3 Sin

LEVELB

3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm3Sm

TABLE A-6: Other sample output sheet generated by the developed software forthe Problem shown in Fig.2, showing codal checks for ServiceLevels A, B & C.

30

Published by : Dr.Vijai Kumar, Head Library & Information Services DivisionBhabha Atomic Research Centre, Mumbai - 400 085, India.