Calculation of Hydrogen and Oxygen Uptake in Fuel Rod Cladding During Severe Accidents Using the Integral Diffusion Method - Final Design Report

Technical Report · Tue Jun 01 00:00:00 EDT 1999

DOI:https://doi.org/10.2172/911489· OSTI ID:911489

Siefken, Larry James

Final designs are described for models of hydrogen and oxygen uptake in fuel rod cladding during severe accidents. Calculation of the uptake involves the modeling of seven processes: (1) diffusion of oxygen from the bulk gas into the boundary layer at the external cladding surface, (2) diffusion from the boundary layer into the oxide layer, (3) diffusion from the inner surface of the oxide layer into the metallic part of the cladding, (4) uptake of hydrogen in the event that the cladding oxide layer is dissolved in a steam-starved region, (5) embrittlement of cladding due to hydrogen uptake, (6) cracking of cladding during quenching due to its embrittlement and (7) release of hydrogen from the cladding after cracking of the cladding. An integral diffusion method is described for calculating the diffusion processes in the cladding. Experimental results are presented that show a rapid uptake of hydrogen in the event of dissolution of the oxide layer and a rapid release of hydrogen in the event of cracking of the oxide layer. These experimental results are used as a basis for calculating the rate of hydrogen uptake and the rate of hydrogen release. A description is given of the implementation of the models for hydrogen and oxygen uptake and cladding embrittlement into the programming framework of the SCDAP/RELAP5/MOD3.3 code.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC07-99ID-13727
• OSTI ID: 911489
• Report Number(s): INEEL/EXT-99-00571; TRN: US0704589
• Country of Publication: United States
• Language: English

Related Subjects

22 - GENERAL STUDIES OF NUCLEAR REACTORS
ACCIDENTS
BOUNDARY LAYERS
DESIGN
DIFFUSION
DISSOLUTION
EMBRITTLEMENT
FUEL RODS
HYDROGEN
IMPLEMENTATION
OXIDES
OXYGEN
PROGRAMMING
QUENCHING
SAFETY REPORTS
SIMULATION
boundary layer
diffusion
embrittlement
fuel rod cladding
hydrogen release
hydrogen uptake
oxide layer
oxygen uptake
SCDAP/RELAP/MOD3.3 code
severe accidents