Code Manual for CONTAIN 2.0 - Federation of American Scientists

(Because of their unwieldy nature, the tables and figures referenced in this appendix are all placed
at the end.)
C. 1.2 Experimental Programs
Experimental programs are of interest primarily because they have provided the principal means for
code validation. Speciiic experiments that are clearly relevant are those on DCH (Surtsey), molten
core-concrete interactions (SURC), aerosol behavior (ABCOVE, LACE), and gadhydrogen
distribution (HDR, NUPEC). Recently emphasis in CONTAIN validation has been placed on
comparisons to the LACE aerosol experiments, the HDR gas transport experiments, the Surtsey
DCH tests, and some recently performed ALWR experiments conducted by Westinghouse Electric
Company and General Electric. Some of the main experimental facilities that have been modeled
with CONTAIN are listed in Table C-2.
C.2 Validation and Assess ment of CONTAIN
The purpose of this section is to discuss the objectives of code validation and the format of the code
validation summaries presented in this appendix. Validation is used in the present context to mean
the capability of the CONTAIN code to accurately represent the physical processes that could occur
within a reactor containment. Section C.2. 1 describes the objectives of code validation and
assessment (CV&A). Section C.2.2 describes the format used to summarize the CONTAIN
validation and assessment efforts.
C.2. 1 Objectives of Code Validation and Assessment (CV&A)
Validation is a necessary part of the development of the CONTAIN code. Code models are often
developed based on an incomplete or approximate understanding of separate, isolated physical
processes. When these models are added to CONTAIN, where many physical processes are
interacting, code predictions are rightfully questioned. The main objective of the CONTAIN CV&A
is to provide an information base broad enough answer such questions and establish confidence in
the code predictions. Other objectives include providing direction for model development, support
for experiment planning, and education for the code user.
Often the issue of CV&A encompasses that of verification. In the present terminology, “verification”
means efforts to ensure that there are no coding errors, and that the calculations represent correct
solutions to the model equations. The term “validation” is used to refer to efforts to determine
whether the models are accurate representations of the physical reality of containment phenomena
by comparing code predictions with experimental results. The verification activities for CONTAIN
are performed as part of the formal testing specified in the Quality Assurance (QA) program
described in Appendix D. In particular, a systematic set of procedures is used for testing CONTAIN
against hand calculations or other codes to identify any model implementation errors or logical errors
in the code. For example, Reference Sci84 is a joint verification and validation investigation
primarily involving the verification of CONTAIN during the code’s early development. However,
parts of the investigation are considered to be validation and are included in the individual CV&As
below.
Rev O c2 6/30/97