1. NAME AND TITLE

TRAC-PF1: Best-Estimate Analysis PWR LOCA

2. CONTRIBUTOR

Borges, R., Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

Dugan, E.T., University of Florida, Gainesville, FL (United States)

Mahaffy, J.H., Los Alamos National Lab., NM (United States)

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV (99.8%) and BAL (0.2%); IBM370

4. NATURE OF PROBLEM SOLVED

TRAC-PF1 performs best estimate analyses of loss of coolant accidents and

other transients in pressurized light water reactors. The program can also be

used to model a wide range of thermal hydraulic experiments in reduced scale

facilities. Models employed include reflood, multi-dimensional two-phase flow,

nonequilibrium thermodynamics, generalized heat transfer, and reactor

kinetics. Automatic steady-state and dump/restart capabilities are provided.

The changes reported in TRACNEWS issues through Number 7 are incorporated in

this release.

5. METHOD OF SOLUTION

The partial differential equations describing the two-phase flow and heat

transfer are solved by finite differences. The heat transfer equations are

treated using a semi implicit differencing technique. The fluid-dynamics

equations in the one-dimensional components use a multistep procedure that

allows the material Courant condition to be violated. The three-dimensional

vessel option uses semi implicit differencing. The finite-difference equations

for hydrodynamic phenomena form a system of coupled, nonlinear equations that

are solved by a Newton-Raphson iteration procedure.

6. RESTRICTIONS OR LIMITATIONS

All storage arrays in TRAC-PF1 can be dynamically allocated; the only limit on

the size of a problem is the amount of central memory available. The number of

reactor components in the problem and the manner in which they are coupled are

arbitrary. Reactor components available include accumulators, pipes,

pressurizers, pumps, steam generators, tees, valves, and vessels with

associated internals.

7. TYPICAL RUNNING TIME

Running time is highly problem dependent and is a function of the total number

of mesh cells, the maximum allowable time-step size, and whether a

three-dimensional vessel model is used. If a purely one-dimensional model is

used, very large time-steps can be used for slow transients. If a

three-dimensional vessel is employed, a material Courant limit in the vessel

may reduce the maximum time-step size allowed and increase the running time.

Complete analysis of a detailed PWR LOCA (including reflood) will require

several CP hours. The longest running sample problem requires about 300

seconds of CPU time on the IBM3033.

8. COMPUTER HARDWARE REQUIREMENTS

The IBM version requires from 4000K to 7000K bytes on an IBM3033. The CPR 20XX

requires 4 Mbytes of RAM for 300K words of LCM, 8 Mbytes of RAM for 800K words

of LCM, and 16 Kbytes fo RAM for 1.8M words of LCM.

9. COMPUTER SOFTWARE REQUIREMENTS

OS/MVT (IBM370); MVS (IBM3033)

10. REFERENCES

Energy Division, Safety Code Development Group, TRAC-PF1: An Advanced

Best-Estimate Computer Program for Pressurized Water Reactor Analysis,

NUREG/CR-3567 (LA-9944-MS), February 1984; B.E. Boyack, TRAC-PF1 Developmental

Assessment, NUREG/CR-3280 (LA-9704-M), July 1983; J.C. Ferguson and M.R.

Turner, TRAP: Plotting Package for TRAC, Revision of NUREG/CR-2054

(LA-8709-MS), rough draft, received August 1981; TRAC-PF1, NESC No. 836.370,

TRAC-PF1 IBM Version Tape Description and Implementation Information, National

Energy Software Center Note 85-19, October 30, 1984\ Dean Dobranich, Lawrence

D. Buxton, and Chung-Nin Channy Wong, TRAC-PF1 LOCA Calculations Using

Fine-Node and Coarse-Node Input Models, NUREG/CR-4044 (SAND84-2305), May 1985;

Gregory D. Spriggs, Jan E. Koenig, and Russel C. Smith, TRAC-PF1 Analysis of

Potential Pressurized-Thermal-Shock Transients at Calvert Cliffs/Unit 1 A

Combustion Engineering PWR, NUREG/CR-4109 (LA-10321-MS), February 1985.

11. CONTENTS OF CODE PACKAGE

NESC Note 85-19; Software Abstract; NUREG/CR-3567; NUREG/CR-3280;

NUREG/CR-2054; Media Includes Source, Sample Problems, Control Information,

Auxiliary Information;\ 1 Mag Tape

12. DATE OF ABSTRACT

Abstract first distributed December 1979. IBM370 version of TRAC-PF1 submitted

August 1984, sample problems executed by NESC September 1984 on an IBM3033.

1. NAME AND TITLE

TRAC-PF1: Best-Estimate Analysis PWR LOCA

2. CONTRIBUTOR

Borges, R., Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

Dugan, E.T., University of Florida, Gainesville, FL (United States)

Mahaffy, J.H., Los Alamos National Lab., NM (United States)

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV (FTN 4.5 FORTRAN compiler); CDC7600

4. NATURE OF PROBLEM SOLVED

TRAC-PF1 performs best estimate analyses of loss of coolant accidents and

other transients in pressurized light water reactors. The program can also be

used to model a wide range of thermal-hydraulic experiments in reduced scale

facilities. Models employed include reflood, multi dimensional two-phase flow,

nonequilibrium thermodynamics, generalized heat transfer, and reactor

kinetics. Automatic steady-state and dump/restart capabilities are provided.

The changes reported in TRACNEWS issues through Number 7 are incorporated in

this release.

5. METHOD OF SOLUTION

The partial differential equations describing the two-phase flow and heat

transfer are solved by finite differences. The heat transfer equations are

treated using a semi implicit differencing technique. The fluid dynamics

equations in the one-dimensional components use a multistep procedure that

allows the material Courant condition to be violated. The three-dimensional

vessel option uses semi implicit differencing. The finite difference equations

for hydrodynamic phenomena form a system of coupled, nonlinear equations that

are solved by a Newton-Raphson iteration procedure.

6. RESTRICTIONS OR LIMITATIONS

All storage arrays in TRAC-PF1 can be dynamically allocated; the only limit on

the size of a problem is the amount of central memory available. The number of

reactor components in the problem and the manner in which they are coupled are

arbitrary. Reactor components available include accumulators, pipes,

pressurizers, pumps, steam generators, tees, valves, and vessels with

associated internals.

7. TYPICAL RUNNING TIME

Running time is highly problem dependent and is a function of the total number

of mesh cells, the maximum allowable time step size, and whether a

three-dimensional vessel model is used. If a purely one-dimensional model is

used, very large time steps can be used for slow transients. If a

three-dimensional vessel is employed, a material Courant limit in the vessel

may reduce the maximum time step size allowed and increase the running time.

Typical computer times for a CDC7600 average 2.3 ms per time step per mesh

call. Complete analysis of a detailed PWR LOCA (including reflood) will

require several CP hours. The longest running sample problem requires about 70

CP seconds on the CDC7600.

8. COMPUTER HARDWARE REQUIREMENTS

The CDC7600 version requires approximately 62K words of small core memory

(SCM) and 131K words of large core memory (LCM).

9. COMPUTER SOFTWARE REQUIREMENTS

SCOPE 2.1.5

10. REFERENCES

Energy Division, Safety Code Development Group, TRAC-PF1: An Advanced

Best-Estimate Computer Program for Pressurized Water Reactor Analysis,

NUREG/CR-3567 (LA-9944-MS), February 1984; B.E. Boyack, TRAC-PF1 Developmental

Assessment, NUREG/CR-3280 (LA-9704-M), July 1983; J.C. Ferguson and M.R.

Turner, TRAP: Plotting Package for TRAC, Revision of NUREG/CR-2054

(LA-8709-MS), rough draft, received August 1981; TRAC-PF1, NESC No. 836.7600,

TRAC-PF1 Tape Description and Implementation Information, National Energy

Software Center Note 83-09, October 29, 1982\ Dean Dobranich, Lawrence D.

Buxton, and Chung-Nin Channy Wong, TRAC-PF1 LOCA Calculations Using Fine-Node

and Coarse-Node Input Models, NUREG/CR-4044 (SAND84-2305), May 1985; Gregory

D. Spriggs, Jan E. Koenig, and Russel C. Smith, TRAC-PF1 Analysis of Potential

Pressurized-Thermal-Shock Transients at Calvert Cliffs/Unit 1 A Combustion

Engineering PWR, NUREG/CR-4109 (LA-10321-MS), February 1985.

11. CONTENTS OF CODE PACKAGE

Media Directory; NESC Note 83-09; Software Abstract; NUREG/CR-3567;

NUREG/CR-3280; NUREG/CR-2054; Media Includes Source, Sample Problem, Auxiliary

Information;\ 1 Mag Tape

12. DATE OF ABSTRACT

Abstract first distributed December 1979. CDC7600 version of TRAC-P1A

submitted March 1979, replaced by revised edition July 1979, TRAC-PD2

submitted August 1980, revised November 1980, replaced June 1981 by

TRAC-PD2/MOD1, replaced November 1982 by TRAC-PF1 submitted August 1981,

revised December 1981,March 1982, and July 1982, sample problems executed by

NESC September 1982 on a CDC7600.

1. NAME AND TITLE

TRAC-PF1: Best-Estimate Analysis PWR LOCA

2. CONTRIBUTOR

Borges, R., Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

Dugan, E.T., University of Florida, Gainesville, FL (United States)

Mahaffy, J.H., Los Alamos National Lab., NM (United States)

3. CODING LANGUAGE AND COMPUTER

SVS FORTRAN 77; IBM PC

4. NATURE OF PROBLEM SOLVED

TRAC-PF1 performs best-estimate analyses of loss of coolant accidents and

other transients in pressurized light water reactors. The program can also be

used to model a wide range of thermal hydraulic experiments in reduced-scale

facilities. Models employed include reflood, multi-dimensional two-phase flow,

nonequilibrium thermodynamics, generalized heat transfer, and reactor

kinetics. Automatic steady-state and dump/restart capabilities are provided.

The changes reported in TRACNEWS issues through Number 7 are incorporated in

this release.

5. METHOD OF SOLUTION

The partial differential equations describing the two-phase flow and heat

transfer are solved by finite differences. The heat-transfer equations are

treated using a semi-implicit differencing technique. The fluid-dynamics

equations in the one-dimensional components use a multistep procedure that

allows the material Courant condition to be violated. The three-dimensional

vessel option uses semi-implicit differencing. The finite-difference equations