Document Details


Title:
OPERATION UPSHOT-KNOTHOLE, PROJECT 29.1, COMPARISON AND EVALUATION OF DOSIMETRY METHODS APPLICABLE TO GAMMA RADIATION, NEVADA PROVING GROUNDS, MARCH - JUNE 1953 (DELETED)
Author(s):
TAPLIN, G V [UNIVERSITY OF CALIFORNIA, SCHOOL OF MEDICINE, LOS ANGELES]; SIGOLOFF, S C [UNIVERSITY OF CALIFORNIA, SCHOOL OF MEDICINE, LOS ANGELES]; DOUGLAS, C H [UNIVERSITY OF CALIFORNIA, SCHOOL OF MEDICINE, LOS ANGELES]; PAGLIA, D E [UNIVERSITY OF CALIFORNIA, SCHOOL OF MEDICINE, LOS ANGELES]; HELLER, C J [UNIVERSITY OF CALIFORNIA, SCHOOL OF MEDICINE, LOS ANGELES]; WALES, D F [UNIVERSITY OF CALIFORNIA, SCHOOL OF MEDICINE, LOS ANGELES]
Subject Terms:
UPSHOT OPERATION; GAMMA RADIATION; DOSIMETRY; MEASURING INSTRUMENTS; BIOLOGICAL EFFECTS; GAMMA DOSIMETRY; PHOTOGRAPHIC FILM DOSEMETERS; MONITORING STATIONS; MEASURING METHODS; UPSHOT-KNOTHOLE OPERATION
Document Location:
Location - NNSA/NSO 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 - CIC@NV.DOE.GOV
Document Type:
REPORT
Publication Date:
1953 Sep 30
Declassification Status:
Sanitized
Document Pages:
0070
Accession Number:
NV0051373
Document Number(s):
WT802EX
OpenNet Entry Date:
1994 Aug 26
Description/Abstract:
THE THREE MAJOR OBJECTIVES AND PARTS OF THIS PROJECT WERE TO COMPARE A ND EVALUATE THE ACCURACY AND PRACTICALITY OF CHEMICAL VS FILM AND OTHE R METHODS OF GAMMA DOSIMETRY FOR RADIATIONS ENCOUNTERED UNDER BOMB CON DITIONS AT SITES RECEIVING ( 1 ) EITHER PROMPT - OR RESIDUAL - GAMMA E XPOSURES OR MIXTURES OF BOTH, ( 2 ) ONLY RESIDUAL-GAMMA RADIATIONS, EI THER NEUTRON INDUCED OR FROM FISSION-PRODUCT FALL-OUT, AND ( 3 ) MIXED NEUTRON-GAMMA IRRADIATION PLUS CORRELATION WITH BIOLOGICAL EFFECTS. T HE MAJOR RESULTS FROM TESTING APPROXIMATELY 15,000 DOSIMETERS DEMONSTR ATE THAT CHEMICAL SYSTEMS ARE CAPABLE OF REGISTERING EXPOSURES TO EITH ER PROMPT OR RESIDUAL BOMB GAMMA RADIATION THROUGHOUT BROAD DOSAGE RAN GES ( 50 TO 5000 R ) ACCURATELY ( PLUS OR MINUS 20 PER CENT ) IN COMPA RISON WITH NATIONAL BUREAU OF STANDARDS FILM STANDARDS, PROVIDED BOTH SYSTEMS ARE CALIBRATED WITH COBALT-60 SOURCES AND ARE PROTECTED FROM S OFT-GAMMA COMPONENTS BY SUITABLE AMOUNTS AND TYPES OF SHIELDING MATERI ALS. ALL CHEMICAL SYSTEMS SHOWN TO BE DOSAGE RATE INDEPENDENT UNDER LA BORATORY CONDITIONS WERE DEMONSTRATED TO RESPOND ACCURATELY AT THE INT ENSITIES OF PROMPT BOMB GAMMA RADIATION ( ABOUT 10-5 R/MIN ) ENCOUNTER ED UNDER SEVERAL SHOTS, THEREBY PROVING THAT CALIBRATION IN THE LABORA TORY IS SUFFICIENT AND THAT RECALIBRATION AT BOMB TESTS IS NO LONGER E SSENTIAL. RESIDUAL BOMB GAMMA RADIATIONS WERE SHOWN TO HAVE A BIOLOGIC ANT SOFT COMPONENT ( BELOW 80 KV ) IN STUDIES DESIGNED TO MEASURE THE PENETRATION OF FALL-OUT GAMMA RADIATION INTO THE ABDOMINAL CAVITIES OF RABBITS AND OF NEUTRON-INDUCED RESIDUAL RADIATION INTO WATER-FILLED P HANTOMS. THE OBSERVED GAMMA MEASUREMENTS OBTAINED WITH CHEMICAL AND FI LM DOSIMETERS EXPOSED INSIDE THE LEAD-HEMISPHERE TEST STATIONS ARE DIF FICULT TO EVALUATE. PRESENTLY AVAILABLE LABORATORY DATA CONCERNING THE RESPONSES OF THESE DOSIMETERS TO NEUTRON FLUXES SIMILAR TO THOSE ENCO UNTERED WITHIN THE HEMISPHERES ARE INSUFFICIENT TO PERMIT ACCURATE EST IMATION OF THE RELATIVE PARTS PLAYED BY GAMMA VS COMBINED FAST - AND S LOW - NEUTRON RADIATIONS IN SYSTEMS WHICH HAVE BEEN EXPOSED TO MIXED N EUTRON-GAMMA FIELDS. AT TEST STATIONS, WHERE NEUTRON FLUXES WERE SUFFI CIENTLY HIGH TO CAUSE MEASURABLE EARLY BIOLOGICAL EFFECTS, THEY ALSO C AUSED RADIOACTIVATION IN THE DOSIMETER COMPONENTS. THEREFORE IT IS NOT POSSIBLE TO USE THESE OBSERVED GAMMA-EXPOSURE VALUES DIRECTLY IN THE E VALUATION OF THE RADIOBIOLOGICAL EXPERIMENTS. AFTER REVIEWING AVAILABL E LABORATORY AND FIELD DATA, IT IS OUR OPINION THAT THE OBSERVED DOSIM ETER READINGS WITHIN LEADHEMISPHERE STATIONS WHICH RECEIVED RADIATION DOSES HIGH ENOUGH TO INDUCE EARLY MANIFESTATIONS OF BIOLOGICAL DAMAGE APPEAR TO REPRESENT NEUTRON EFFECTS ALMOST ENTIRELY. THIS INTERPRETATI ON IS SUPPORTED BY THE NATURE OF THE BIOLOGICAL CHANGES WHICH WERE DIS TINCTLY CHARACTERISTIC OF NEUTRON EXPOSURES. PRIOR TO FURTHER FIELD TE STS THE SENSITIVITY OF BOTH CHEMICAL AND FILM SYSTEMX TO FAST AND SLOW SLOW NEUTRONS SHOULD BE DETERMINED QUANTITATIVELY UNDER CONTROLLED LA BORATORY CONDITIONS; FURTHERMORE, STRICT ATTENTION MUST BE GIVEN TO FA CTORS OF GEOMETRY DURING THE PLANNING FOR, AND THE OPERATION OF, ANY F UTURE COORDINATED BIOLOGICAL DOSIMETRIC EXPERIMENTS. THERE IS ALSO A N EED TO IMPROVE AVAILABLE INSTRUMENTS FOR MEASURING RESIDUAL BOMB GAMMA RADIATIONS IN RESPECT TO THEIR CAPACITY TO REGISTER THE BIOLOGICALLY EFFECTIVE SOFT COMPONENTS ( BELOW 80 KV ) PRESENT IN THE SPECTRUM. TO CORRECT SUCH INSTRUMENTS FOR SERIOUS DISCREPANCIES DUE TO ENERGY DEPEN DENCE, MODIFICATION OF THE AMOUNT AND TYPES OF SHIELDING MATERIALS USE D IN CONSTRUCTION OF THEIR CONTAINERS IS NEEDED. FINALLY, RADIATION ST ANDARDS MORE SUITABLE THAN RADIUM OR COBALT-60 SHOULD BE FOUND TO CALI BRATE INSTRUMENTS DESIGNED TO MEASURE THE RESIDUAL GAMMA RADIATIONS EN COUNTERED AT SITES NEAR GROUND ZERO OR AT DISTANT FALL-OUT AREAS.


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