NESC0326: AIROS-2A, Space-Independent Reactor Kinetics and Space-Dependent Heat Transfer, Mass Transfer

[Program Service | Recent programs]

NESC0326 AIROS2A (Abstract last modified 04-APR-1984)

AIROS-2A, Space-Independent Reactor Kinetics and Space-Dependent Heat Transfer, Mass Transfer

Abstract Table of Contents:

1. NAME OR DESIGNATION OF PROGRAM - AIROS2A

2. COMPUTER FOR WHICH PROGRAM IS DESIGNED AND OTHER MACHINE VERSION PACKAGES AVAILABLE -

To request or retrieve programs click on the one of the active versions below. A password and special authorization is required.

Explanation of the status codes.

Program-name Package-ID Status AIROS-2A NESC0326/01 Tested AIROS-2A(OLD) NESC0326/02 Obsolete

Machines used: Package-ID Orig.Computer Test Computer NESC0326/01 IBM 360 series IBM 360 series

3. DESCRIPTION OF PROBLEM OR FUNCTION - AIROS2A solves   the   space-
independent  reactor  kinetics  equations  and  provides  for  the
determination of reactivity by solving in addition the discretized
equations that represent the spatial  heat and mass transfer model
for several  fuel channels.   In addition,  variation of  the film
coefficient with  flow is accounted  for along with  the provision
for flow decay and afterglow heating.   Scrams can be initiated by
delayed  signals   from  instruments   that  sense   any  quantity
calculated,   e.g.,   power,  inverse   period   or   temperature.
Generalized feedback equations are used  to provide flexibility in
the  models that  represent multichannel  heat transfer  including
conduction and  convection, energy, pressure and  other phenomenon
such as fuel  melting, coolant boiling and  voiding burn-out.  The
reactivity equation is also  generalized.  The reactivity feedback
coefficients  can  be constant  or  vary  as  the square  root  or
reciprocal of temperature.  Furthermore, any feedback variable can
be used to  initiate a reactivity scram, each with  a unique delay
time.  An input  generator computes the conduction  and convection
coefficients for an n x m  nodal, multichannel system using built-
in tables  of specific heat,  density, conductivity  and viscosity
for the common fuel, structure and coolant materials, and performs
an initial temperature calculation.  The  film coefficients may be
specified or  calculated  using  Lyon's equation  or  the  Dittus-
Boelter equation.

4. METHOD OF SOLUTION - The numerical technique used to integrate the
neutron and feedback  differential equations is that  developed by
E. R.  Cohen as previously used  in the AIREK codes.   An improved
interval  switching  technique  allows   rapid  calculations  with
predetermined accuracy.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - Maxima of -
    15 delayed neutron precursor groups
   400 feedback variables
    90 feedback variables printed out
Any number of channels and nodes per channel within the limitation
above are allowed.

6. TYPICAL RUNNING TIME - 1 to 2 minutes are required for a problem
with 6 delayed neutron precursor groups and 50 feedback variables
(including CRT).

7. UNUSUAL FEATURES OF THE PROGRAM -
   (a)  A special provision is made for reactor startup problems
        resulting in a large reduction in running time.
   (b)  Many of the required input data are pre-set but can be
        changed if desired.
   (c)  Addressable input data are used so that on multiple cases,
        only changes need be specified.
   (d)  A restart feature is provided wherein restart cards are
        punched upon abnormal problem termination and/or on an
        input option.
   (e)  Extensive printed and graphical displays are provided as
        follows - power, inverse period, reactivity and any 90
        feedback variables.  Printing and display of feedback
        variables is under the user's control and the latter can
        be grouped on CRT frames as desired.
   (f)  Conduction and convection coefficients may be input and/or
        calculated by means of an input generator which in addi-
        tion performs an initial temperature calculation.
   (g)  Phenomenological models for change of phase are incorpo-
        rated.

8. RELATED AND AUXILIARY PROGRAMS -

9. STATUS
NESC0326/01: 01-MAY-1972 Tested at NEADB
NESC0326/02: 04-APR-1984 Obsolete

10. REFERENCES  -
- R.A. Blaine:
  AI Environment Report (May 1967).
- R.A. Blaine:
  Modifications to Airos II-A
  W00048, AI Computing Notice No. 118 (April 4, 1968).
NESC0326/01:
- R.A. Blaine and R.F. Berland:
  Simulation of Reactor Dynamics, Volume I - A Description of
  AIROS IIA
  NAA-SR-12452 (September 1967).

11. MACHINE REQUIREMENTS - 256K byte IBM360 and an SC-4020 graphical
display device

12. PROGRAMMING LANGUAGE(S) USED -
NESC0326/01: FORTRAN+ASSEMBLER

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED - OS/360.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS -   Two
new features have been added to  the latest version of AIROS2A.  A
contact resistance term  has been added in the  calculation of the
overall heat transfer coefficients, UA.  A new subroutine has been
added to simulate setback or controller action of a single bank of
control  rods.  If  an  SC-4020 graphical  display  device is  not
available, the  AICRT 3 display routine  can be rewritten,  or all
routines but TAPOUT  and PRINT can be deleted from  the last link.
The NAA SC-4020 (OS) subroutine package is available through -
                  UAIDE Librarian
                  c/o Stromberg-Carlson
                  P. O. Box 2449
                  San Diego, California  92112

15. NAME AND ESTABLISHMENT OF AUTHOR -
                 A. N. Nickols
                 Codes Coordinator
                 Atomics International
                 P. O. Box 309
                 Canoga Park, California  91304

16. MATERIAL AVAILABLE -
NESC0326/01:
NESC0326_01.001   SOURCE PROGRAMME                                 4470 records
NESC0326_01.002   OVERLAY,DD CARDS+INPUT DATA                        83 records
NESC0326_01.003   PRINTED OUTPUT                                   3068 records

17. CATEGORIES  -

- E.  Space
Independent Kinetics
- H.  Heat Transfer and Fluid Flow

Keywords: COHEN EQUATION, COMPUTER GRAPHICS, DELAYED NEUTRON PRECURSORS, FEEDBACK, REACTIVITY, REACTOR KINETICS