Document Details


Title:
OPERATION PLUMBBOB, PROGRAM 2, NEUTRON AND GAMMA RADIATION FROM SHOT LAPLACE, NEVADA TEST SITE, MAY - OCTOBER 1957 (DELETED)
Author(s):
CHIMENT, J A [DEFENSE ATOMIC SUPPORT AGENCY, DOD]; GOETZ, J L [DEFENSE ATOMIC SUPPORT AGENCY, DOD]; FACER, G C [DEFENSE ATOMIC SUPPORT AGENCY, DOD]
Subject Terms:
PLUMBBOB OPERATION; GAMMA RADIATION; NEUTRONS; LAPLACE EVENT; RADIATION FLUX; RESEARCH PROGRAMS; RADIATION DOSES; DOSE RATES; GAMMA DOSIMETRY; DECAY
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:
1959 Nov 20
Declassification Status:
Sanitized
Document Pages:
0040
Accession Number:
NV0051368
Document Number(s):
WT1541EX
OpenNet Entry Date:
1994 Aug 26
Description/Abstract:
THE OBJECTIVES OF THIS EXPERIMENT WERE TO DETERMINE FOR SHOT LAPLACE, A 1.22-KT DEVICE FIRED LATE IN OPERATION PLUMBBOB: (1) INTENSITY AND D ECAY OF THE NEUTRON-INDUCED GAMMA FIELD; (2) NEUTRON FLUX AND SPECTRA AS A FUNCTION OF DISTANCE; (3) NEUTRON FLUX AS A FUNCTION OF SOIL DEPT WITH CERTAIN SELECTED DETECTORS; AND (4) NEUTRON DOSE AND INITIAL GAM MA DOSE AS A FUNCTION OF DISTANCE. THE DOCUMENTATION OF THE INDUCED FI ELD INTENSITY AND ITS DECAY WAS ACCOMPLISHED THROUGH USE OF TWO TYPES OF GAMMA SURVEY METERS, THE AN/PDR-TIB AND THE JORDAN MODEL AGB-10SR. NEUTRON FLUX AND SPECTRA WERE MEASURED BY THE THRESHOLD-DETECTOR TECHN IQUE, EMPLOYING GOLD, CADMIUM-SHIELDED GOLD, PLUTONIUM, NEPTUNIUM, URA NIUM, AND SULFUR FOR GROUND-SURFACE MEASUREMENTS, AND GOLD, CADMIUM-SH IELDED GOLD, AND SULFUR FOR SOIL-DEPTH MEASUREMENTS. VARIOUS TYPES OF FILM-BADGE AND CHEMICAL DOSIMETERS WERE USED TO MEASURE THE INITIAL GA MMA DOSE, WHILE NEUTRON DOSE WAS DETERMINED BY CALCULATION FROM THE FL UX-SPECTRA RESULTS. THE NEUTRON-INDUCED GAMMA RADIATION FIELD AND ITS DECAY FROM H+1 TO H+36 HOURS WAS SUCCESSFULLY DOCUMENTED. THE OBSERVED DECAY RATE INDICATED SODIUM-24 AND MANGANESE-56 AS BEING THE MAJOR CO NTRIBUTING RADIONUCLIDES DURING THE TIME COVERED BY THE OBSERVATIONS. A SURVEY OF THE NEUTRON-INDUCED FIELD AT H+27 HOURS INDICATED DOSE-RAT E LEVELS RANGING FROM 2.6 R/HR AT A SLANT RANGE OF 320 YARDS TO 1.38 M R/HR AT 2,015 YARDS. WHEN EXTRAPOLATED BACK TO H+1 HOUR, THE 320-YARD READING WAS FOUND TO BE EQUIVALENT TO 16.4 R/HR. THE DATA OBTAINED IN THE DOCUMENTATION OF THERMAL ( GOLD ) AND FAST ( SULFUR ) NEUTRON FLUX ES WITH SOIL DEPTH CONFIRMED EARLIER OBSERVATIONS THAT THERMAL FLUX PE AKS AT A DEPTH OF APPROXIMATELY 4 INCHES, WHEREAS THE HIGH-ENERGY FLUX DEGRADES RAPIDLY WITH DEPTH. NEUTRON IRRADIATION OF ELEMENTAL SAMPLES OF SODIUM, CHROMIUM, AND MANGANESE PRODUCED THE INDUCED ACTIVITIES OF NA-24, CR-51, AND MN-56. THE SPECIFIC ACTIVATION WAS REASONABLY WELL R ELATED TO THE CROSS SECTIONS OF THE REACTIONS INVOLVED. THE MEASURED N EUTRON DOSE EXCEEDED THAT PREDICTED BY TM 23-200 BY AND AVERAGE FACTOR OF 2.6 FOR RANGES BETWEEN 300 AND 700 YARDS. ALTHOUGH THIS IS WITHIN THE PREDICTION-METHOD RELIABILITY FACTOR OF 4 QUOTED FOR WEAPONS OF TH IS TYPE, THE LAPLACE DATA IS CONSIDERED REPRESENTATIVE OF DEVICES AND SHOULD BE USED TO IMPROVE THE PREDICTION TECHNIQUES AS THEY APPLY TO W EAPONS. THE INITIAL GAMMA DOSE DATA SHOWED THAT LAPLACE PRODUCED A GRE ATER-THAN-PREDICTED GAMMA DOSE AT ALL RANGES, WITH THE GREATEST DISCRE PANCY OCCURRING AT THE CLOSE-IN RANGES. THE EFFECTIVE MEAN FREE PATH O F THE INITIAL GAMMA RADIATION AT RANGES IN EXCESS OF 1,500 YARDS WAS 4 40 YARDS, SLIGHTLY GREATER THAN THE VALUE PREDICTED ( USING A RELATIVE AIR DENSITY OF 0.8 ) OF 425 YARDS.


<< Return to Search Results