Thermal analysis for a spent reactor fuel storage test in granite

Conference · Mon Sep 01 00:00:00 EDT 1980

OSTI ID:59213

Montan, D N

A test is conducted in which spent fuel assemblies from an operating commercial nuclear power reactor are emplaced in the Climax granite at the US Department of Energy`s Nevada Test Site. In this generic test, 11 canisters of spent PWR fuel are emplaced vertically along with 6 electrical simulator canisters on 3 m centers, 4 m below the floor of a storage drift which is 420 m below the surface. Two adjacent parallel drifts contain electrical heaters, operated to simulate (in the vicinity of the storage drift) the temperature fields of a large repository. This test, planned for up to five years duration, uses fairly young fuel (2.5 years out of core) so that the thermal peak will occur during the time frame of the test and will not exceed the peak that would not occur until about 40 years of storage had older fuel (5 to 15 years out of core) been used. This paper describes the calculational techniques and summarizes the results of a large number of thermal calculations used in the concept, basic design and final design of the spent fuel test. The results of the preliminary calculations show the effects of spacing and spent fuel age. Either radiation or convection is sufficient to make the drifts much better thermal conductors than the rock that was removed to create them. The combination of radiation and convection causes the drift surfaces to be nearly isothermal even though the heat source is below the floor. With a nominal ventilation rate of 2 m{sup 3}/s and an ambient rock temperature of 23{sup 0}C, the maximum calculated rock temperature (near the center of the heat source) is about 100{sup 0}C while the maximum air temperature in the drift is around 40{sup 0}C. This ventilation (1 m{sup 3}/s through the main drift and 1/2 m{sup 3}/s through each of the side drifts) will remove about 1/3 of the heat generated during the first five years of storage.

• Research Organization: California Univ., Livermore, CA (United States). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 59213
• Report Number(s): UCRL-83995; CONF-801124-8; TRN: 80:018567
• Resource Relation: Conference: 3. annual meeting of the Materials Research Society, Boston, MA (United States), 17-20 Nov 1980; Other Information: PBD: Sep 1980
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
58 GEOSCIENCES
54 ENVIRONMENTAL SCIENCES
SPENT FUEL STORAGE
UNDERGROUND STORAGE
GRANITES
THERMAL ANALYSIS
SPENT FUELS
NEVADA TEST SITE
CONTAINERS
PWR TYPE REACTORS
HEATERS
CALCULATION METHODS
SIMULATION
AGE DEPENDENCE
SPACE DEPENDENCE
THERMAL CONDUCTION
ISOTHERMS
VENTILATION
RADIOACTIVE WASTE DISPOSAL
UNDERGROUND DISPOSAL
MATHEMATICAL MODELS
FIELD TESTS
Yucca Mountain Project