Personnel dosimetry associated with the handling of large numbers of 3-kg $sup 239$Pu billets

Conference · Sat Jan 01 04:00:00 EST 1972

OSTI ID:4318592

Myers, D S; Prevo, C T; Willis, C A ^[1]

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1. ed.

From third Health Physics Society midyear topical symposium; Los Angeles, California, USA (29 Jan 1969). See CONF-690103P1. The current operations of the Lawrence Radiation Laboratory, Livermore, critical array study group involve the handling of up to 128 plutonium billets. Each of the billets contains approximately 3 kilograms of /sup 239/Pu (including small quantities of other plutonium isotopes) clad in aluminum and stainless steel. When the billets are handled individually, they present a hand dose problem; however, when they are in sizable arrays, the wholebody dose becomes the controlling factor. Although /sup 240/Pu is present only in small quantities, its relatively short spontaneous fission half-life produces a significant neutron flux (approximately 5 x 10/sup 5/ neutrons/sec per billet). The neutron film (Kodak type NTA) proved quite unsatisfactory for measuring whole-body neutron doses in these studies; thus the technique used to establish the whole-body neutron dose rate was to measure the neutron-to-gamma dose rate ratio for the array environment radiation using a variety of gamma and neutron detectors. Since the neutron-to-gamma dose rate ratio is dependent upon the size, spacing, and moderation of the array, a new ratio is determined for each array. A neutron-to-gamma dose rate ratio was also established for billet surface radiation using computer techniques. The neutron dose is then established by applying the measured neutron-to-gamma ratio to the whole-body gamma dose as measured by the film badge, and to ihe gamma hand dose as measured by thermoluminescent dosimeters. (auth)

• Research Organization: Univ. of California, Livermore
• NSA Number: NSA-29-030204
• OSTI ID: 4318592
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*PERSONNEL DOSIMETRY
*PLUTONIUM 239-- MATERIALS HANDLING
CRITICALITY
GAMMA DOSIMETRY
N52300* --Nuclear Materials & Waste Management--Handling Equipment & Procedures
NEUTRON DOSIMETRY
PHOTOGRAPHIC FILM DOSEMETERS
RADIATION DOSES
RADIATION PROTECTION