Charcoal performance under accident conditions in light-water reactors. Final report

Technical Report · Fri Mar 01 04:00:00 EST 1985

OSTI ID:6040146

Deitz, V R

Nuclear-grade carbons were systematically degraded by exposure to unfiltered outdoor air with decrease in radioactive methyl iodide trapping. Local meteorological conditions of high humidity combined with atmospheric pollutants in the test vicinity contributed jointly to the degradation. When service carbons were exposed to radiation levels of 10/sup 7/ to 10/sup 9/ rads, the iodine isotope exchange capacity was regenerated. The adsorptive properties were only slightly improved. It was possible to regenerate the iodine isotope-exchange efficiencies by reaction with airborne chemical reducing agents such as hydrazine for carbons removed from nuclear power operations. The depth profile in methyl iodide-131 penetration changed from simple exponentional through new carbons to a non-linear profile for weathered and service aged carbons. The behavior is attributed to the chromatographic distribution of the contaminants that accumulate in the bed. The removal of radioactive iodine depends on a minimum of 3 distinguishable processes: adsorption on the activated carbon, iodine isotope exchange with impregnated iodine-127, and chemical combination with impregnated tertiary amines when present. When a carbon is new, all 3 mechanisms are at peak performance. After the carbon is placed in service, the 3 mechanisms degrade at different rates; the adsorption process degrades faster than the others.

• Research Organization: Naval Research Lab., Washington, DC (USA)
• OSTI ID: 6040146
• Report Number(s): NUREG/CR-3990; NRL-Memo-5528; ON: TI85901281
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
ADSORPTION
AIR
AIR CLEANING SYSTEMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON
DAYS LIVING RADIOISOTOPES
ELEMENTS
ENGINEERED SAFETY SYSTEMS
FLUIDS
GASES
HALOGENATED ALIPHATIC HYDROCARBONS
INTERMEDIATE MASS NUCLEI
IODINATED ALIPHATIC HYDROCARBONS
IODINE 131
IODINE ISOTOPES
ISOTOPES
ISOTOPIC EXCHANGE
METHYL IODIDE
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PERFORMANCE
RADIATION EFFECTS
RADIOISOTOPES
REACTOR ACCIDENTS
REACTORS
REGENERATION
REMOVAL
SORPTION
WATER COOLED REACTORS
WEATHERING