Section 194.23 - Models and computer codes(a) Any compliance application shall include:(1) A description of the conceptual models and scenario construction used to support any compliance application.(2) A description of plausible, alternative conceptual model(s) seriously considered but not used to support such application, and an explanation of the reason(s) why such model(s) was not deemed to accurately portray performance of the disposal system.(3) Documentation that:(i) Conceptual models and scenarios reasonably represent possible future states of the disposal system;(ii) Mathematical models incorporate equations and boundary conditions which reasonably represent the mathematical formulation of the conceptual models;(iii) Numerical models provide numerical schemes which enable the mathematical models to obtain stable solutions;(iv) Computer models accurately implement the numerical models; i.e., computer codes are free of coding errors and produce stable solutions;(v) Conceptual models have undergone peer review according to § 194.27 .(b) Computer codes used to support any compliance application shall be documented in a manner that complies with the requirements of ASME NQA-2a-1990 addenda, part 2.7, to ASME NQA-2-1989 edition. (Incorporation by reference as specified in § 194.5 .)(c) Documentation of all models and computer codes included as part of any compliance application performance assessment calculation shall be provided. Such documentation shall include, but shall not be limited to:(1) Descriptions of the theoretical backgrounds of each model and the method of analysis or assessment;(2) General descriptions of the models; discussions of the limits of applicability of each model; detailed instructions for executing the computer codes, including hardware and software requirements, input and output formats with explanations of each input and output variable and parameter (e.g., parameter name and units); listings of input and output files from a sample computer run; and reports on code verification, benchmarking, validation, and quality assurance procedures;(3) Detailed descriptions of the structure of computer codes and complete listings of the source codes;(4) Detailed descriptions of data collection procedures, sources of data, data reduction and analysis, and code input parameter development;(5) Any necessary licenses; and(6) An explanation of the manner in which models and computer codes incorporate the effects of parameter correlation.(d) The Administrator or the Administrator's authorized representative may verify the results of computer simulations used to support any compliance application by performing independent simulations. Data files, source codes, executable versions of computer software for each model, other material or information needed to permit the Administrator or the Administrator's authorized representative to perform independent simulations, and access to necessary hardware to perform such simulations, shall be provided within 30 calendar days of a request by the Administrator or the Administrator's authorized representative.