CONFINEMENT OF AIRBORNE RADIOACTIVITY. Progress Report, January--June 1971.

Abstract

Radiolytic desorption tests of a series of carbon samples containing KI 3 , KI, triethylenediamine (TEDA), or combinations of TEDA and KI showed that a 10 x 16 mesh coconut shell carbon containing 1% TEDA, 2% KI,and a proprietary flame retardant retained iodine better than all products tested except those containing higher TEDA concentrations.Ignition temperature measurements on the same series of samples showed that the 1% TEDA -2% KI product has an ignition temperature of about 330°C under SRP flow conditions (the same as the KI3 carbon). The 1% TEDA -2% KI carbon has been selected to replace the unimpregnated carbon currently used in the Savannah River reactor confinement system.-2 - CONTENTS

Confinement of airborne radioactivity. Progress report: July--December 1973

“…9 The test conditions (IO-minute loading of elemental iodine at ambient temperature and humidity followed by 4 hours desorption at 180°C) were selected to prevent damage to the "Teflon"-coated test apparatus and "Neoprene"* "0"-rings used as seals in the apparatus. The lSO°c temperature is also the upper limit of usefulness for TEDA-impregnated carbons because TEDA boils at 174°C and flashes at -1900C.…”

“…heat of combustion of the TEDA. 12 With the selection of a suitable replacement carbon for the confinement system (a 1% TEDA-2% KI carbon having satisfactory iodine retention properties and an acceptable ignition temperature), 1 3 the anomalous behavior of some of the KI3-impregnated carbons noted in earlier screening tests 9 ,lO was investigated.…”

Confinement of airborne radioactivity. Progress report, January--December 1974

“…The high-temperature desorption test was initially designed .as a screening test to aid in selecting potential replacement carbons for the Savannah River confinement system. 2 The test conditions (lO-min. loading of elemental iodine at ambient temperature and humidity followed by 4-hr desorption at l80•C and <1% relative humidity) were selected to prevent damage to the TefZoncoated test apparatus and Neoprene "O"-rings used as seals in the apparatus (registered tradenames of E. I. du Pont de Nemours and Co.) The 180•C temperature is also near the upper limit of usefulness for nuclear carbons because thermal desorption of iodine becomes significant in this temperature range.…”