Document Details

(670 K)

MOVEMENT OF DISCRETE PARTICLES IN THE 100- TO 200-MICRON DIAMETER RANGE THROUGH THE GASTROINTESTINAL TRACT OF LABORATORY ANIMALS AND MAN

FURCHNER, J E; RICHMOND, C R; SULLIVAN, M F

HREX

Location - DOE/NNSA NUCLEAR TESTING ARCHIVE Address - P.O. Box 98521 City - Las Vegas State - NV Zip - 89193-8521 Phone - (702)794-5106 Fax - (702)862-4240 Email - NTA@NV.DOE.GOV

JOURNAL ARTICLE

Never classified

0013

NV0701344

1994 Aug 27

2017 Dec 21

ESTIMATIONS OF THE RADIATION DOSE INCURRED FROM SMALL RADIOACTIVE PARTICLES PASSING THROUGH THE GASTROINTESTINAL TRACT ARE THE FOCUS OF THIS REPORT. PARTICLE DIAMETERS WERE MEASURED WITH AN IMAGE-SPLITTING EYEPIECE ATTACHED TO A MICROSCOPE. CALIBRATION WAS ACHIEVED BY USE OF A 100-U GRATICULE DIVIDED INTO 2-U INTERVALS. AN AVERAGE DIAMETER WAS OBTAINED FOR EACH PARTICLE BASED ON SIX OBSERVATION; THE PARTICLE AS REMOVED AND REPOSITIONED BETWEEN EACH READING TO MINIMIZE ERRORS RESULTING FROM DEVIATIONS FROM SPHERICITY. RADIONUCLIDES WERE MEASURED BY GAMMA-RAY SPECTROSCOPY. THE DUAL CRYSTAL DETECTORS (EACH 8 IN. DIAMETER BY 4 IN. THICKNESS) WERE COVERED BY 0.005 IN. OF ALUMINUM TO ENHANCE SENSITIVITY AT LOW ENERGIES. A 7-IN. THICK STEEL SHIELD SURROUNDED THE DETECTORS. MICE AND BEAGLE HOUNDS OF BOTH SEXES WERE USED. INCLUSION IN THE EXPERIMENT WERE HUMANS WHO RECEIVED A NO. 5 GELATIN CAPSULE CONTAINING TWO 235UC(2) FUEL CORES AND ONE 54MN-LABELED SPHERE. MANGANESE-54 LABELED CERAMIC SPHERES AND 235UC(2) FUEL CORES IN THE 100 TO 200 U DIAMETER SIZE RANGE ARE NOT PREFERENTIALLY RETAINED IN THE GI TRACTS OF EXPERIMENTAL ANIMALS, INCLUDING MAN, BECAUSE OF SMALL SIZE. IN THE RAT, NO SPHERES WERE PASSED UNTIL THE 8TH HR. AFTER INGESTION. MOVEMENT TO THE CECUM AND LARGE INTESTINE REQUIRED 4 - 6 HR. DOGS FED 235UC(2) FUEL CORES SHOWED VARIABLE GTT VALUES WITH AN ESTIMATED AVERAGE OF ROUGHLY 15-20 HR. A CHRONIC FEEDING EXPERIMENT DEMONSTRATED RAPID MOVEMENT OF PARTICLES THROUGH THE GI TRACT TO THE CECUM AND LARGE INTESTINE.