RELAP5 International User’s Seminar November 7, 2007 Paul Bayless, INL Doug Barber, ISL RELAP5-3D Developmental Assessment Plan

2 Outline General description of plan Description of assessment cases

3 What is developmental assessment? Using analytic solutions and experiment data to determine how well specific models of the code work Provides insight into how well the code may be able to model specific phenomena It is not a comprehensive assessment of the code’s capabilities Performed by the code developers, rather than by independent users Results become part of the code documentation

4 Developmental assessment is part of the code adequacy evaluation process.

5 A developmental assessment plan for RELAP5-3D has been developed. Joint effort between ISL and INL Plan includes –Automated testing framework –Description of how the assessment will progress –List of the expected assessment cases –Preparation of code manual Volume 3

6 Developmental Assessment Objectives Perform an assessment of a recent code version Update the information in the RELAP5 code manuals, specifically Volume III Automate, as much as possible, the developmental assessment process for future code versions

7 Automated Testing Framework Provides a structure for performing the assessment Used in conjunction with automated validation scripts and tools (SNAP) Code-to-data comparisons Code-to-code comparisons Provides metrics on the comparisons

8 Developmental Assessment Process Collect input models and experiment data for the selected cases Develop automated validation (AV) scripts for each case Run preliminary calculations Identify cases that need more work –Check/modify input model –Rerun Prepare draft documentation of results Run all cases with a final version of RELAP5-3D (completed FORTRAN 90) Prepare final documentation (ECD June 2009)

9 Developmental Assessment Cases Cases selected based on –Availability of input models –Availability of experiment data –Code models exercised 54 cases have been selected –15 phenomenological problems –28 separate effects experiments –11 integral effects experiments Some adjustments may be made during the process

10 Phenomenological Test Cases Bubbling steam through liquid Conduction enclosure Core power Fill/drain Gravity wave/horizontal CCFL (1-D/3-D) Manometer Point kinetics ramp Pryor pressure comparison 3-D flows (3 cases) Water faucet Water over steam (1-D/3-D)

11 Separate Effects Experiments (1) Bennett heated tube (CHF) Chan (two-phase pump) Christensen (subcooled boiling) Dukler (CCFL) Edwards pipe (vapor generation) FLECHT SEASET (bundle heat transfer) GE jet pump GE level swell (two-phase level) GOTA (radiation heat transfer)

12 Separate Effects Experiments (2) LOFT (accumulator) Marviken (critical flow) MB2 (steam generator behavior) MIT pressurizer Moby Dick (critical flow) NEPTUNUS (pressurizer) ORNL THTF (bundle heat transfer) RIT (CHF) UPTF (downcomer CCFL)

13 Separate Effects Phenomena Two-phase level (10) Critical heat flux (7) Critical flow (5) Subcooled boiling (5) Post-CHF heat transfer (5) CCFL (4) Pressurizer behavior (2) Accumulator behavior (1) Steam generator behavior (1) Jet pump (1) Two-phase pump behavior (1)

14 Integral Effects Cases Three large break LOCAs –LOFT –LOBI Four small break LOCAs –ROSA –LOFT Four natural circulation tests –Semiscale

15 Volume III of the RELAP5 Code Manual Results from the developmental assessment will be documented in Volume III Code version and user options will be identified Judgments about the code/data comparisons will be made –Based on the CSAU terminology –More qualitative than quantitative –Metrics in the automated testing framework may allow a more quantitative approach