1. NAME AND TITLE
SCOPE: Computer Code System for Shipping Cask Optimization and Parametric Evaluation.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran IV; IBM 3033.
4. NATURE OF PROBLEM SOLVED
Given the neutron and gamma-ray shielding requirements as input, SCOPE may be used as a
conceptual design tool for the evaluation of various casks designed to carry square fuel assemblies,
circular canisters of nuclear waste material, or circular canisters containing "intact" spent-fuel
assemblies. It may be used to evaluate a specific design or to search for the maximum number of full
assemblies (or canisters) that might be shipped in a given type of cask. In the "search" mode, SCOPE
will use built-in packing arrangements and the tabulated shielding requirements input by the user to
"design" a cask carrying one fuel assembly (or canister); it will then continue to increment the number
of assemblies (or canisters) until one or more of the design limits can no longer be met. In each case
(N = 1,2,3...), SCOPE will calculate the steady-state temperature distribution throughout the cask and
perform a complete 1-D space/time transient thermal analysis following a postulated half-hour fire;
then it will edit the characteristic dimensions of the cask (including fins, if required), the total weight
of the loaded case, the steady-state temperature distribution at selected points, and the maximum
transient temperature in key components. With SCOPE, the effects of various design changes may
be evaluated quickly and inexpensively.
5. METHOD OF SOLUTION
SCOPE assumes that the user has already made an independent determination of the neutron and
gamma-ray shielding requirements for the particular type of cask(s) under study. The amount of
shielding required obviously depends on the type of spent fuel or nuclear waste material, its burnup
and/or exposure, the decay time, and the number of assemblies or canisters in the cask. Source terms
(and spectra) for spent PWR and BWR fuel assemblies are provided at each of 17 decay times, along
with recommended neutron and gamma-ray shield thicknesses for Pb, Fe, and U-metal casks
containing a number (1-25) of 1-, 2-, 3-, 4-, 7-, or 10-year-old PWR spent fuel assemblies.
6. RESTRICTIONS OR LIMITATIONS
The key physical features of those casks considered by the SCOPE code include: an inner steel
shell, a gamma-ray shield, an outer steel shell, a neutron shield, and an outside barrel. Depending on
the amount of decay heat that must be dissipated, the cask(s) may or may not have circumferential fins.
Inside the cask(s), the spent fuel assemblies (or canisters) may be separated by means of an aluminum
or copper insert. It is assumed that the spent fuel is to be shipped dry (i.e., casks with forced
circulation cooling systems are not considered). Lead, iron, or uranium metal may be specified as the
gamma-ray shielding material, while the neutron shield is always assumed to be a common mixture
of water and ethylene glycol containing ~1 wt% boron.
7. TYPICAL RUNNING TIME
On an IBM 3033/MVS machine, SCOPE requires ~0.13 seconds of CPU time for each cask
8. COMPUTER HARDWARE REQUIREMENTS
This version of SCOPE is operable on an IBM 3033 computer with a minimum of 105 K bytes of
9. COMPUTER SOFTWARE REQUIREMENTS
The IBM version runs on the IBM 3033 OS/MVS or IBM 360/91 OS/MVT systems with standard
I/O. The code will compile under either the Fortran H or Fortran Q compiler.
J. A. Bucholz, "Scoping Design Analyses for Optimized Shipping Casks Containing 1-, 2-, 3-, 5-,
7-, or 10-Year-Old PWR Spent Fuel," ORNL/CSD/TM-149 (January 1983).
"SCALE: A Modular Code System for Performing Standardized Analyses for Licensing
Evaluation," NUREG/CR-0200 (ORNL/NUREG/CSD-2), Vols. I, II, and III (April 1982).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2MB) DOS diskette which contains the source
code plus sample problem input and output.
12. DATE OF ABSTRACT
March 1985, revised October 1991.
KEYWORDS: OPTIMIZATION; PARAMETRIC MODELS; SELF SHIELDING; HEAT TRANSFER; PWR; SHIPPING CASK DESIGN