NOTES
population average dose equivalent and commitment of l.2rem from man-made radioactivity on
Bikini Island.
N. A. GREENHOUSE
R. P. MILTENBERGER
E. T. LESSARD
Safety and Environmental
Protection Division
Upton, NY 11973
References
Co75 Conard R. A.. et ai, 1975, *A Twenty Year
Review of Medical Findings in a Marshallese
Population Accidentally Exposed to Radioactive
Fallout’, Brookhaven National Laboratory Rep.
BNL 50424.
Co77 Personal Communications with S. Cohn,
Medical Dept., Brookhaven National Laboratory.
Gr79 Greenhouse N. A.. Miltenberger R. P. and
Lessard E. T., 1979, “Externa Exposure
Measurements at Bikini Atoll’, Brookhaven
National Laboratory Rep. BNL 51003.
Gu76 Gudiksen P. H.. Crites T. R. and Robison
W. L,. 1976. “External Dose Estimates for
Future Bikini Atoll Inhabitants”, Lawrence
Livermore Laboratory Rep. UCRL-51879, Rev. 1.
Mi80 Miltenberger R. P.. Greenhouse N. A. and
Lessard E. T., 1980, “Whole Body Counting
Results from [974 to 1979 for Bikini. Island
Residents”, Health Phys. in press.
Ro77 Robison W. L., Phillips W. A. and Colsher
C. S., 1977, “Dose Assessment at Bikini Atoil”,
Lawrence Livermore Laboratory Rep. UCRL$1879, Part 5.
851
experimenters from medical centers. the academic
community and industry is also an integral part of
the DOSARfacility mission. The primary research
tool at the facility in the Health Physics Research
Reactor (HPRR). The HPRR is a smail, unmoderated fast reactor which may be operated in
the steady state or the pulse mode (Aué65). Since
the HPRR is frequently used for personnel dosimetry applications research, the effective neutron
quality factor (QF) of the reactor spectrum is of
interest. Quality factors caiculated by Monte Carlo
methods for the HPRR have been published in this
journal (Mu74:; Si78). The effective neutron QF
has recently been measured for the HPRR in the
unshielded condition as well as behind each of
three of the most commonly used shields: 12-cm
thick Lucite, 13-cm thick steel and 270-cm thick
concrete. The measurements are described and the
results are presented below. Three types of detectors were used in the QF measurements:
(1) SNOOPY—This remmeter is the commercialt version of the Andersson—Braun portable
neutron monitor (An64). The sensor is a BF,
counter surrounded by a boron-loaded polyethy- ©
lene moderator. Details are available in the literature (Ha75; Te75). The SNOOPY wascalibrated
using the DOSAR NSD-60 *"Cf source which
produced 6.45 mrem/hr at | m. This dose rate was
determined from the well-known source flux using.
a conversion factor of 3 10-* rad - cm*/neutron
($t70) and a QF of 9.6¢ for the *7Cf.
(2) RD-|—The RD-| sensor is a 7.3 -cmdiameter spherical ionization chamberfilled with
tissue equivalent (TE) gas and having 0.16-cm-
thick walls made of Shonka A-150 TE plastic
(Go78). The sensor is part of a new on-line dosi-
metry system$ installed at the DOSARfacility to
monitor experimental irradiations at the HPRR. It
has been calibrated using standard gamma sources
as well as with the accurately known HPRR mixed
Heaith Physics Vol. 38 (May). pp. 851-893
Pergamon Press Lid.. 1980. Printed in the U.S_A.
Neutron Quality Factor Measurements at
the Oak Ridge National Laboratory’s
Dosimetry Applications Research Facility*
(Received 13 July 1979: accepted 17 September
1979)
THE Oak Ridge National Laboratory’s (ORNL)
Dosimetry Applications Research (DOSAR)facility is used for a wide range of dosimetry studies
by the staff. Research in cooperation with
radiation fieids. The RD-1 sensor measures total
*Research sponsored by the Division of Pollutant Characterization and Safety Research, U.S.
Dept. of Energy under Contract W-7405-ENG-26
with Union Carbide Corp.
tManfactured by Tracerlab (Richmond, California).
tThe QF for 7"Cf was determined by multiply-
ing the fractional fluence in various energy intervals (St70) by the average QF for neutrons of
those energies as reported in Table 2 of NCRP
Report 38 (NCRP71).
$Manufactured
(Tulsa, OK).
by
Digital
Data Dosimetry