RRFM 2009 Transactions - European Nuclear Society

estimate the gamma dose rate at the irradiation location were also performed using
Landauer TLD-100 dosimeters.
The incident gamma and neutron components were also measured using a set of FarWest TM
paired ion chambers, in keeping with the recommendations of the International BNCT
Dosimetry Exchange [7]. The gamma dose was measured at 2.26 cGy/min whereas the
neutron dose was measured at 1.72 cGy/min.
Final gamma and neutron dose rate measurements surrounding the facility were also
performed while the BNCT facility was in various configurations at 10 MW operation. In the
“sample load” configuration, a field of 0.25 mSv/hr gamma and 0.25 mSv/hr neutron exists
inside the irradiation chamber. In “beam on,” there is a field of 0.45 mSv/hr neutron on the
lid, a field of 0.50 mSv/hr gamma on the east shielding blocks, a field of 0.25 mSV/hr on the
beam axis on the north shield block, and a field of 0.25 mSv/hr on the west side.
VI. Conclusions and Future Work
Parameter studies, design calculations and initial performance measurements have been
completed for the new BNCT facility. These results indicate that a more than adequate
thermal neutron beamline facility has been designed and constructed for BNCT cell and
small-animal radiobiology studies at the MURR. Near future work will include small animal
phantom dosimetery measurements using flux wires and the FarWest TM paired ion
chambers. Animal phantoms, containing flux wires, will be placed in the beam and the
neutron dose will be calculated by taking the ratio of the flux wire activity measured on the
paired ion chambers with the flux wire activity measured in the phantom. Kerma factors will
be applied to calculate the primary biological components of the non-specific neutron dose
(hydrogen knock on damage n(H,H’)n’, n( 14 N,p) 14 C and hydrogen prompt gamma production)
and the dose from the reaction with 10 B.
VII. References
[1] Hawthorne M.F. and Lee, M.W., 2003. A Critical Assessment of Boron Target
Compounds for Boron Neutron Capture Therapy, Journal of Neuro Oncology 62:33-
45.
[2] Kim, Myong-Seop et al., 2007. Development and characteristics of the HANARO
neutron irradiation facility for applications in the boron neutron capture therapy field,
Phys. Med. Biol. 52:2553-2566.
[3] Rhoades, WA, et al., 1993. TORT-DORT: Two and Three-Dimensional Discrete-
Ordinates Transport, Radiation Shielding Information Center, Oak Ridge National
Laboratory, CCC-543.
[4] Breismeister, JF, 1999. ”MCNP – A General Monte Carlo N-Particle Transport Code,
Version 4C, LA-13709-M, Los Alamos National Laboratory, USA.
[5] Roussin, R.W., 1980. BUGLE-80 Coupled 47-Neutron, 20 Gamma-Ray P3 Cross
Section Library, DLC-75, Radiation Shielding Information Center, Oak Ridge National
Laboratory, USA.
[6] Lee, Byung-Chul, 2007. Korea Atomic Energy Research Institute, Private
communication.
[7] Järvinen, H., and Voorbraak, W.P., 2003. Recommendations for the Dosimetry of
Boron Neutron Capture Therapy, Report 21425/03 55339/C, NRG Petten, The
Netherlands.
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