NEA-1279 MODICO.

MODICO, 1-D Time-Dependent 1 Group, 2 Group Neutron Diffusion with Delayed Neutron Precursors

NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROGRAM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHORS, MATERIAL, CATEGORIES

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1. NAME OR DESIGNATION OF PROGRAM: MODICO.

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2. COMPUTERS

To submit a request, click below on the link of the version you wish to order. Rules for end-users are available here.

Program name	Package id	Status	Status date
MODICO	NEA-1279/01	Tested	04-SEP-1992

Machines used:

Package ID	Orig. computer	Test computer
NEA-1279/01	IBM 3081	DEC VAX 8810

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3. DESCRIPTION OF PROGRAM OR FUNCTION

The program solves the 1-D time-dependent one and two group coarse-mesh neutron diffusion equations, coupled with the equations for the delayed-neutron precursor, in plane geometry.

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4. METHOD OF SOLUTION

The program is based on a simple coarse-mesh cubic approximation formula for the spatial behaviour of the flux inside each interval. An implicit scheme (the time-integrated method) is used for the advancement of the solution. The resulting (block three-diagonal) matrix is inverted at each time step by Thomas' method.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Number of coarse- mesh intervals LE 80; number of material regions LE 10; number of delayed-neutron precursor groups LE 10. Typical mesh sizes range from 5 cm to 20 cm; typical step length (non-prompt critical transients) ranges from 0.005 to 0.1 seconds.

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6. TYPICAL RUNNING TIME

Each time step requires about 0.001 seconds for each spatial interval (with 2 energy groups and 6 delayed neutron groups), on the IBM 3081.

NEA-1279/01

NEADB compiled the program on a DEC VAX 8810 computer and ran the three test cases included in this package in about 10 seconds of CPU time.

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7. UNUSUAL FEATURES OF THE PROGRAM

Analytical quasi-static treatment of top and bottom reflectors (optional). Time step size automatically adapted to the flux trend (optional).

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8. RELATED AND AUXILIARY PROGRAMS:

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9. STATUS

Package ID	Status date	Status
NEA-1279/01	04-SEP-1992	Tested at NEADB

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10. REFERENCES

- P. Camiciola, D. Cundari, B. Montagini:
"A-Course-Mesh Method for 1-D Reactor Kinetics"
Ann. Nucl. Energy, 13,11, p. 629 (1986)

NEA-1279/01, included references:

- P. Camiciola, D. Cundari and B. Montagnini:
MODICO - A Coarse Mesh Code for One-Dimensional Reactor Kinetics.
Draft Report (1989)

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11. MACHINE REQUIREMENTS

MODICO uses three logical units. A problem having 80 meshes can be run using as much as 350K bytes of fast memory.

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12. PROGRAMMING LANGUAGE(S) USED

Package ID	Computer language
NEA-1279/01	FORTRAN-IV

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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

NEA-1279/01

VMS 5.3 (VAX 8810).

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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

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15. NAME AND ESTABLISHMENT OF AUTHORS

- P. Camiciola
  ENEA DISP
  via Vitaliano Brancati 48
  00198 ROME, Italy
- D. Cundari
  ANSALDO S.p.A.
  via G. D'Annunzio 113
  16121 GENOVA, Italy
- B. Montagnini
  Dipartimento di Costruzioni Mecchaniche e Nucleari
  dell' Universita di Pisa
  via Diotisalvi 2
  56100 PISA, Italy

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16. MATERIAL AVAILABLE

NEA-1279/01

File name	File description	Records
NEA1279_01.001	This information file	52
NEA1279_01.002	JCL and control information	28
NEA1279_01.003	Orig. JCL to run MODICO at ENEA DISP	31
NEA1279_01.004	MODICO FORTRAN source	2092
NEA1279_01.005	Aux. FORTRAN subroutine for test problem 1	16
NEA1279_01.006	Aux. FORTRAN subroutine for test problem 2	57
NEA1279_01.007	Aux. FORTRAN subroutine for test problem 3	49
NEA1279_01.008	Sample problem input 1	18
NEA1279_01.009	Sample problem input 2	18
NEA1279_01.010	Sample problem input 3	18
NEA1279_01.011	Sample problem output 1	147
NEA1279_01.012	Sample problem output 2	183
NEA1279_01.013	Sample problem output 3	139