last modified: 01-MAR-1969 | catalog | categories | new | search |

NEA-0262 REFLOS.

REFLOS, Fuel Loading and Cost from Burnup and Heavy Atomic Mass Flow Calculation in HWR

top ]
1. NAME OR DESIGNATION OF PROGRAM:  REFLOS.
top ]
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
REFLOS NEA-0262/01 Tested 01-MAR-1969

Machines used:

Package ID Orig. computer Test computer
NEA-0262/01 IBM 360 series IBM 360 series
top ]
3. NATURE OF PHYSICAL PROBLEM SOLVED

REFLOS is a programme for the evaluation of fuel-loading schemes in heavy water moderated reactors. The problems involved in this study are:
a) Burn-up calculation for the reactor cell.
b) Determination of reactivity behaviour, power distribution,  attainable burn-up for both the running-in period and the  equilibrium of a 3-dimensional heterogeneous reactor model;    investigation of radial fuel movement schemes.
c) Evaluation of mass flows of heavy atoms through the reactor  and fuel cycle costs for the running-in, the equilibrium, and    the shut down of a power reactor.
If the subroutine for treating the reactor cell were replaced by a suitable routine, other reactors with weakly absorbing moderators  could be analyzed.
top ]
4. METHOD OF SOLUTION

Nuclear constants and isotopic compositions of the different fuels in the reactor are calculated by the cell-burn-up programme and tabulated as functions of the burn-up rate (MWD/T). Starting from a known state of the reactor, the 3-dimensional heterogeneous reactor programme (applying an extension of the technique of Feinberg and Galanin) calculates reactivity and  neutron flux distribution using one thermal and one or two fast neutron groups. After a given irradiation time, the new state of the reactor is determined, and new nuclear constants are assigned to the various defined locations in the reactor.
Reloading of fuel may occur if the prescribed life of the reactor is reached or if the effective multiplication factor or the power form  factor falls below a specified level. The scheme of reloading to be  carried out is specified by a load vector, giving the number of channels to be discharged, the kind of movement from one to another  channel and the type of fresh fuel to be charged for each single reloading event. After having determined the core states characterizing the equilibrium period, and having decided the fuel reloading scheme for the running-in period of the reactor life, the  fuel cycle costs are evaluated following proposals of the EURATOM Economic Handbook.
top ]
5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Maximum number of groups of channels having rotation symmetry is 60.
Maximum number of groups of channels having specular symmetry is 120.
Maximum number of harmonics for the approximation of the axial flux  distribution is 19.
Highest order of Bessel functions for the approximation of the radial flux distribution is 12.
Maximum number of axial pieces of a channel with possibly different  neutronic properties is 20.
Maximum number of neutron groups: two fast, one thermal.
Maximum number of different types of channels in the reactor is 10. Maximum number of burn-up steps characterizing one type of channel is 50.
top ]
6. TYPICAL RUNNING TIME

A. Burn-up calculation: about 2 minutes for one type of fuel.
B. Reactor calculation: (for 60 channels) 3 minutes + 1 minute for one state of the reactor.
C. Cost calculation: about 3 minutes.
top ]
7. UNUSUAL FEATURES OF THE PROGRAM

The only moderator considered is heavy water.
Xenon is assumed to be in equilibrium during the burn-up process.
Reflector and moderator are assumed to have the same macroscopic neutron cross-sections.
Spatial Xenon and temperature distributions within the reactor core are not considered.
The channels of the reactor are treated as line sources and line sinks for neutrons. Thus, their finite size is not taken into account. As a consequence, the channels must not be too large nor too closely packed within the moderator.
The programme does not take into account the condition that the fast flux vanishes at the extrapolated boundary of the radial reflector.The error thereby introduced is negligible if the radial reflector is greater or equal to 4*SQRT(tau), where tau is the slowing down area of the moderator.
The slowing down properties of the materials within the channel are not treated separately but must be included in a suitable way by modifying the slowing down properties of the moderator.
top ]
8. RELATED AND AUXILIARY PROGRAMS

REFLOS incorporates modified versions of ORACLE-1 and TRIHET. An auxiliary program is necessary for the creation of a binary data library.
top ]
9. STATUS
Package ID Status date Status
NEA-0262/01 01-MAR-1969 Tested at NEADB
top ]
10. REFERENCES

- W. Boettcher, E. Schmidt:
  REFLOS, A Code for the Refined Evaluation of Fuel Loading Schemes
  EUR 4250 E, CCR EURATOM Ispra (1969).
top ]
11. MACHINE REQUIREMENTS

300 kbytes memory, overlay facility, 2 private tapes and 3 scratch units in addition to the units required for input, output and punch. Clock is required for control of execution  time.
top ]
12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NEA-0262/01 FORTRAN-IV
top ]
13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED:  IBM OS 360.
top ]
14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The programme has been compiled by the FORTRAN IV H-compiler with optimization O=2.
top ]
15. NAME AND ESTABLISHMENT OF AUTHOR

    W. Boettcher, E. Schmidt
    Direction for Heavy Water Reactors                                       Joint Research Centre
    21020 - Ispra
    Italy
top ]
16. MATERIAL AVAILABLE
NEA-0262/01
File name File description Records
NEA0262_01.001 SOURCE IBM 360/65 7023
NEA0262_01.002 OVERLAY CARDS & INPUT DATA 220
NEA0262_01.003 PROGRAM TO PREPARE THE LIBRARY 56
NEA0262_01.004 INPUT DATA FOR LIBRARY PROGRAM 1050
NEA0262_01.005 REFLOS OUTPUT 1205
top ]
17. CATEGORIES
  • B. Spectrum Calculations, Generation of Group Constants and Cell Problems
  • C. Static Design Studies
  • D. Depletion, Fuel Management, Cost Analysis, and Power Plant Economics

Keywords: burnup, cost, distribution, fuel cycle, fuel management, heavy water moderated reactors, heterogeneous reactors, neutron flux, power distribution, reactivity, three-dimensional.