NEA-0806 NAIAD.

NAIAD, LOCA Transient and Steady-State 2 Phase Flow in Channel Network

NAME OR DESIGNATION OF PROGRAM, COMPUTER, NATURE OF PHYSICAL PROBLEM SOLVED, 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 OR MONITOR UNDER WHICH PROGRAM IS EXECUTED, ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES

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1. NAME OR DESIGNATION OF PROGRAM: NAIAD.

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2. COMPUTERS

To submit a request, click below on the link of the version you wish to order. Only liaison officers are authorised to submit online requests. Rules for requesters are available here.

Program name	Package id	Status	Status date
NAIAD	NEA-0806/01	Tested	01-JUN-1977

Machines used:

Package ID	Orig. computer	Test computer
NEA-0806/01	IBM 370 series	IBM 370 series

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3. NATURE OF PHYSICAL PROBLEM SOLVED

The transient (including LOCA) and steady state flow of two-phase compressible light water in a network of heated channels. The momentum flux term is included and unequal phase velocities allowed. A lumped fuel model and detailed surface heat transfer are included. Thermodynamic equilibrium of the two phases is assumed. Discharge flow is calculated intrinsically from the hydraulic equations. The ANC pump model is included.

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4. METHOD OF SOLUTION

The one-dimensional conservation equations of mass, momentum and energy are solved in each channel by a numerically stable implicit finite difference scheme. The network is then solved by an accelerated Gauss-Seidel iteration scheme.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Versions of the code can be easily generated to handle any size problem. Standard code is limited to 50 axial nodes and 10 channels.

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6. TYPICAL RUNNING TIME

Depends on complexity of the problem. Approximately 15 milliseconds per time step per node on model 65 CPU. Sample problem takes 1 minute on model 65.

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7. UNUSUAL FEATURES OF THE PROGRAM

The code user may supply special routines to set up and dynamically modify boundary conditions. These routines can also be used to control time-stepping, write supplementary output and model hydraulic components not routinely allowed for in the standard code.

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8. RELATED AND AUXILIARY PROGRAMS

Four supplementary programs are provided:
(a) A precompiler to expand common blocks in the MAIN code and the user's special routines.
(b) A prelinker to insert ALIAS and NAME cards into object modules for subroutine library creation.
(c) A program to generate steam tables for the code.
(d) A program to load pump characteristic data.
The steam table generating program requires the ASTEM package (ANCR-1026).

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9. STATUS

Package ID	Status date	Status
NEA-0806/01	01-JUN-1977	Tested at NEADB

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10. REFERENCES: - G.D. Trimble and W.J. Turner:, AAEC/E378 (1976).

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11. MACHINE REQUIREMENTS: 240 kbytes main storage. 132 column printer.

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12. PROGRAMMING LANGUAGE(S) USED

Package ID	Computer language
NEA-0806/01	FORTRAN+ASSEMBLER

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13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED: IBM 360 O.S. MVT.

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14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The FORTRAN system message data set is assumed to be unit 3.

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15. NAME AND ESTABLISHMENT OF AUTHOR

      G.D. Trimble and W.J. Turner
      Australian Atomic Energy Commission Research Establishment
      Private Mail Bag
      Sutherland, N.S.W. 2232
      Australia

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16. MATERIAL AVAILABLE

NEA-0806/01

File name	File description	Records
NEA0806_01.001	INFORMATION	15
NEA0806_01.002	PROCEDURES	196
NEA0806_01.003	JOB CONTROL FOR NAIAD	75
NEA0806_01.004	PRELINKER	214
NEA0806_01.005	LIBRARY ROUTINES - ASSEMBLER	2888
NEA0806_01.006	LIBRARY ROUTINES - F4	69
NEA0806_01.007	PRECOMPILER SOURCE - F4	64
NEA0806_01.008	COMMONS 50/10	72
NEA0806_01.009	COMMONS 100/20	72
NEA0806_01.010	NAIAD SOURCE - F4	2405
NEA0806_01.011	SSGEN SOURCE	348
NEA0806_01.012	ASTEM SUBROUTINES - F4	1551
NEA0806_01.013	SSGEN SAMPLE PROBLEM INPUT	18
NEA0806_01.014	SSGEN SAMPLE PROBLEM OUTPUT	25
NEA0806_01.015	PUMPLOAD SOURCE - F4	37
NEA0806_01.016	PUMPLOAD SAMPLE PROBLEM INPUT	106
NEA0806_01.017	PUMPLOAD SAMPLE PROBLEM OUTPUT	118
NEA0806_01.018	NAIAD SAMPLE PROBLEM INPUT	141
NEA0806_01.019	NAIAD SAMPLE PROBLEM OUTPUT	373

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17. CATEGORIES

G. Radiological Safety, Hazard and Accident Analysis

Keywords: blowdown, compressible flow, finite difference method, heat transfer, loss-of-coolant accident, transients, two-phase flow.