LASS, An IBM 704 Program for Calculating System Stability

Technical Report · Wed Jul 01 04:00:00 EDT 1964

DOI:https://doi.org/10.2172/4679524· OSTI ID:4679524

Katz, Sidney M. ^[1]; St. John, Daniel S. ^[1]

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1. Du Pont de Nemours (E.I.) and Co., Aiken, SC (United States). Savannah River Lab.

The LASS code is an IBM 704 program to compute the stability and transient response of dynamic systems. Up to 50 system equations (in up to 50 system variables) are written in linearized form (for example, by assuming small perturbations about a steady-state operating condition). After taking Laplace transforms, a system of linear, algebraic equations is obtained in which the coefficients are polynomials in the Laplace transform variable s. The LASS code accepts the matrix of these coefficient polynomials, reduces it to a single transfer function (ratio of polynomials in s), and calculates and plots the stability characteristics, frequency response, and transient response of the system. A sample problem from a nuclear reactor system has been used to illustrate the use of the code. The system contained nine equations and system variables, three parameters (power level and two reactivity coefficients), and one input excitation. The 130-page output contained the transient response inputs for each of five power levels. The total running time on the IBM 704 was 40 minutes.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Aiken, SC (United States). Savannah River Lab.
• Sponsoring Organization: US Atomic Energy Commission (AEC); USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• NSA Number: NSA-19-001837
• OSTI ID: 4679524
• Report Number(s): DP--894
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
97 MATHEMATICS AND COMPUTING
Computer programs
Criticality Studies
FORTRAN
Nuclear Criticality Safety Program (NCSP)
Reactor Technology