6 research outputs found
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Thermal hydraulic analysis for the PWR blowdown heat transfer separate-effects program
Rod surface temperatures in the THTF are sensitive to flow variations. Thus, accurate prediction of THTF rod behavior will require accurate prediction of flows. RELAP 4 MOD 5 Update 2 predicts absolute pressures and some flows fairly well. It homogenizes energy and density fronts and predicts flows poorly where flow reversals or frequent density changes occur. RELAP's predicted quality increases coupled with the quality dependence of its CHF correlation produce predictions of early, sustained rod surface temperature excursions even when these do not, in reality, occur. Further work is necessary to obtain local fluid conditions of sufficient accuracy to allow utilization of experimentally determined CHF and heat transfer coefficients
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Peer review of RELAP5/MOD3 documentation
A peer review was performed on a portion of the documentation of the RELAP5/MOD3 computer code. The review was performed in two phases. The first phase was a review of Volume 3, Developmental Assessment problems, and Volume 4, Models and Correlations. The reviewers for this phase were Dr. Peter Griffith, Dr. Yassin Hassan, Dr. Gerald S. Lellouche, Dr. Marino di Marzo and Mr. Mark Wendel. The reviewers recommended a number of improvements, including using a frozen version of the code for assessment guided by a validation plan, better justification for flow regime maps and extension of models beyond their data base. The second phase was a review of Volume 6, Quality Assurance of Numerical Techniques in RELAP5/MOD3. The reviewers for the second phase were Mr. Mark Wendel and Dr. Paul T. Williams. Recommendations included correction of numerous grammatical and typographical errors and better justification for the use of Lax`s Equivalence Theorem
PWR blowdown heat transfer separate-effects program - Thermal-Hydraulic Test Facility experimental data report for test 177. [Contains microfiche data]
Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) test 177, which is part of the ORNL Pressurized-Water Reactor (PWR) Blowdown Heat Transfer Separate-Effects Program. Objective of the program is to investigate the thermal-hydraulic phenomenon governing the energy transfer and transport processes that occur during a loss-of-coolant accident in a PWR system. Test 177 was conducted at the request of Idaho National Engineering Laboratory ''for use in the independent assessment of RELAP4/MOD6.'' Primary purpose of this report is to make the reduced instrument responses during test 177 available. The responses are presented in graphical form in engineering units and have been analyzed only to the extent necessary to assure reasonableness and consistency. The data are presented in microfiche form
PWR blowdown heat transfer separate-effects program data evaluation report: system response for thermal-hydraulic test facility test series 100
Selected reduced instrument responses and analyses of the indicated phenomena are presented for Thermal-Hydraulic Test Facility (THTF) test series 100, which is part of the PWR Blowdown Heat Transfer Separate-Effects Program. The objective of the program is to investigate the thermal-hydraulic phenomena that govern the energy transfer and transport processes occurring during a postulated loss-of-coolant accident in a pressurized-water reactor system. Comparisons are made between the trends indicated by the reduced instrument responses and the thermal-hydraulic transient simulator RELAP4/MOD5 (update 2) to aid in understanding the phenomenological sequences. The results of verification studies of RELAP's performance in prediction of the THTF data are presented
Blowdown Heat Transfer Separate-Effects Program. Quarterly progress report, April-June 1980
Two transient film boiling tests were run - one in upflow, the other in downflow. The purpose of these tests was to provide experimental heat transfer data that could be used in an assessment of several film boiling correlations used in current thermal-hydraulic computer codes. The tests were designed to provide accurate posttest calculations of heat fluxes, surface temperatures, and local fluid conditions. THe Upflow Film Boiling Test 3.03.6AR was run on May 21, 1980, in the THTF. This test resulted in single-phase fluid flow at the test section inlet (subcooled) during the time the bundle was in high-flow film boiling. Furthermore, no flow reversal occurred during the test. Preliminary posttest analysis indicates that the calculation of mass flows at the inlet to the test section should result in numbers with relatively small uncertainties. We are optimistic that local fluid conditions can be calculated for this test with an accuracy sufficient for correlation evaluation. 7 figs
Blowdown heat transfer separate-effects program. Quarterly progress report, January-March 1980
Six additional bundle uncovery/recovery tests were performed in the Thermal-Hydraulic Test Facility during January, bringing the total number of these tests to eight. Data taken during the tests were found to be contaminated by numerous spurious spikes. Work to remove the spurious spikes is under way. Posttest analysis of the tests is approx.20% completed. The recovery portion of one of the tests will be analyzed by COBRA/TRAC, currently being developed by Pacific Northwest Laboratories (PNL). Work to debug the code for this application is in progress at PNL. The uncovery/recovery tests apparently caused damage to the 0-rings that form part of the loop pressure boundary. Refurbishment of the 0-ring seal system is being performed concurrently with scheduled loop modifications that include installation of ten in-bundle differential pressure instruments. Design, procurement, and fabrication of the in-bundle gamma densitometer system are continuing on schedule