Technical support for a proposed decay heat guide using SAS2H/ORIGEN-S data

Technical Report · Thu Sep 01 04:00:00 EDT 1994

DOI:https://doi.org/10.2172/43752· OSTI ID:43752

Hermann, O W; Parks, C V; Renier, J P ^[1]

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1. Oak Ridge National Lab., TN (United States)

Major revisions are proposed to the current US Nuclear Regulatory Commission decay heat rate guide entitled ``Regulatory Guide 3.54, Spent Fuel Heat Generation in an Independent Spent Fuel Storage Installation,`` using a new data base produced by the SAS2H analysis sequence of the SCALE-4 system. The data base for the proposed guide revision has been significantly improved by increasing the number and range of parameters that generally characterize pressurized-water-reactor (PWR) and boiling-water-reactor (BWR) spent fuel assemblies. Using generic PWR and BWR assembly models, calculations were performed with each model for six different burnups at each of three separate specific powers to produce heat rates at 20 cooling times in the range of 1 to 110 y. The proposed procedure specifies proper interpolation formulae for the tabulated heat generation rates. Adjustment formulae for the interpolated values are provided to account for differences in initial {sup 235}U enrichment and changes in the specific power of a cycle from the average value. Finally, safety factor formulae were derived as a function of burnup, cooling time, and type of reactor. The proposed guide revision was designed to be easier to use. Also, the complete data base and guide procedure is incorporated into an interactive code called LWRARC which can be executed on a personal computer. The report shows adequate comparisons of heat rates computed by SAS2H/ORIGEN-S and measurements for 10 BWR and 10 PWR fuel assemblies. The average differences of the computed minus the measured heat rates of fuel assemblies were {minus}07 {plus_minus} 2.6% for the BWR and 1.5 {plus_minus} 1.3% for the PWR. In addition, a detailed analysis of the proposed procedure indicated the method and equations to be valid.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications; Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 43752
• Report Number(s): NUREG/CR--5625; ORNL--6698; ON: TI95011701
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
AFTER-HEAT
BURNUP
BWR TYPE REACTORS
FUEL ASSEMBLIES
HEAT RATE
O CODES
PWR TYPE REACTORS
RADIATION HEATING
REGULATIONS
REGULATORY GUIDES
S CODES
SAFETY
SPENT FUEL STORAGE
SPENT FUELS