An Analysis of Chlorine Gas Release. KARA BROWN
(University of California San
Diego, La Jolla, CA, 92092)
GEORGE FULTON (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Chlorine is an
extremely reactive and harmful gas that can cause a myriad of health
problems within seconds of exposure. This report is an analysis
of current chlorine safety regulations in place at Lawrence Livermore
National Laboratory for Building 153. It was found that the rapidity
at which usable amounts of chlorine gas could be released into
the main workspace of the building that the emergency response
alarm for a leak needed to remain active. The calculations go through
a series of different possibilities including the concentration
of chlorine gas with multiple size cylinders, the difference that
ventilation makes, and the amount of time it would take the ventilation
to get the concentration of chlorine gas down to different airborne
exposure standards such as the IDLH, STEL, 8-Hour TLV, or Mean
Odor Threshold.
Analysis of Sharps Safety Procedures and Injury Prevention Methods at Lawrence Livermore National Laboratory. NICOLE
SADLER (University of California, Davis, CA, 95616) LESLIE HOFHERR (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Today’s hazardous
world demands safe work practices. An employee’s risk of injury
and infection increases significantly when he handles sharps. To
assess sharps use and compliance with correct safety controls and
practices, the author generated a survey form. This form was based
on current safety standards and used to conduct face-to-face interviews
of Lawrence Livermore National Laboratory (LLNL) personnel who
were using biological materials and sharps in research projects.
At LLNL, current safety standards are summarized in what is known
as the Environmental Safety and Health (ES&H) Manual. Close
scrutinization of the ES&H manual confirmed consistency with
the current sharps use standards. The Occupational Safety & Health
Administration (OSHA) Bloodborne Pathogens Standard mandates that
employers maintain a sharps injury log. The survey was designed
to determine if any discrepancies between the number of sharps
injuries sustained and those reported existed. However, the LLNL
sharps injury log was not currently available but will be available
in the future, and therefore such comparisons were not performed
as part of this analysis. Twenty percent of the facilities using
sharps at LLNL were evaluated. During the assessments, almost sixty
percent of the labs had an observable sharps safety hazard. These
safety breaches fell into one of the following three categories:
improper recapping technique, presence of an exposed or improperly
discarded sharp, or overfilled sharps container. Nearly twenty
percent of the individuals interviewed either had injured himself
with a sharp or knew of someone affiliated with his particular
lab that had been injured. Seventy-five percent of the reported
injuries occurred in a BSL-2 lab. Most researchers at LLNL use
scalpels and needles. Half of the researchers reuse their sharps,
a practice that should be avoided. The statistical results of the
surveys alerted safety personnel to the need for sharps training
and further evaluation of sharps use at LLNL.
Analyzing the Structure and Function of Novel Cytochromes from a Natural Microbial
Community. ANNA SIEBERS (University of California, San
Diego, La Jolla, CA, 92093)
MICHAEL P. THELEN (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
The Richmond
mine in Iron Mountain, California, provides an unusual ecosystem
suitable for the growth of microbial biofilms which produce many
unique proteins. Through iron oxidation, these proteins facilitate
acid mine drainage (AMD). Because this habitat is extremely acidic,
survival is an extraordinary feat and the process of environmental
selection is rare. In order to understand the mechanisms by which
these organisms oxidize iron and gain electrons for energy, biochemical
studies were applied. More specifically, column chromatography,
spectrophotometry, and gel electrophoresis were used to determine
the proteins present in different biofilms. Two specific locations
of the mine researched were the AB drift and Ultraback C (UBC),
which were both found to contain at least five different types
of protein and a large amount of heme-bound cytochromes. Another
application of these methods was to investigate proteins playing
a major role within the community; one protein selected was cytochrome
579 (Cyt579) due to its abundance in the biofilm, iron oxidizing potential,
and signature absorbance of 579nm. The structure and function of
Cyt579 could
be characterized by the isolation of its heme, which was completed
using column chromatography; however, one of the challenges has
been liberating the heme from the column. Further research, including
acid-base and temperature profiling of Cyt579 should help elucidate its structural changes within alternate
environments and metabolism within the community.
Development of Optical Trapping Raman and Coherent Anti-Stokes Raman Scattering
(CARS) Spectroscopy for Analysis of Phospholipid Vesicles. DANIEL AUTREY (Fayetteville State University, Fayetteville, MC, 28301) DR. JAMES
W. CHAN (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Raman spectroscopy
is a powerful technique that is being applied to the study of biological
systems in our laboratory. Raman spectroscopy is a laser-based
method of chemical analysis that generates vibrational signal from
molecular bonds. There are two overall goals of this project. The
first aim is to obtain the spontaneous Raman signatures of individual
optically-trapped phospholipid vesicles. Two types of phospholipids
are analyzed in this experiment, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine
(DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC).
Single 0.4 µm diameter phospholipid vesicles are successfully trapped
in a laser-trapping Raman system and their spectral signatures
simultaneously acquired. Additional experiments were carried out
to determine the vibrational modes of DPPC that are sensitive to
the gel-liquid crystal phase transition occurring at 41°C. Characterization
of the DPPC phospholipids in the liquid crystal state is important
to understanding the permeability of the lipid membrane. After
the phase transition, a noticeable slight shift in the CH2 deformation mode from 1462 cm-1 to 1458 cm-1 occurs which may be explained by a weakening of the dispersion
forces between neighboring phospholipids, allowing the CH2 groups
to vibrate more freely. The second aim of this project is to develop
a broadband coherent anti-Stokes Raman scattering (CARS) optical
trapping system to enable the monitoring of rapid biological processes.
To achieve this end, the laser conditions necessary to generate
broadband light by the coupling of femtosecond pulsed near-infrared
light into a photonic crystal fiber (PCF) was investigated.
Development of Optical Trapping Raman and Coherent Anti-Stokes Raman Scattering
(CARS) Spectroscopy for Analysis of Phospholipid Vesicles. SALIMA HAMED (Fayetteville State University, Fayetteville, NC, 28301)
JAMES W. CHAN (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Raman spectroscopy
is a powerful technique that is being applied to the study of biological
systems in our lab. Raman spectroscopy is a laser-based method
of chemical analysis that generates vibrational signal from molecular
bonds. There are two overall goals of this project. The first aim
is to obtain the spontaneous Raman signatures of individual optically-trapped
phospholid vesicles. Two types of lipids are analyzed in this experiment,
1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and (DMPC).
Single 0.4 µm diameter lipid vesicles are successfully trapped
in a laser trapping Raman system and their spectral signatures
simultaneously acquired. Additional experiments were carried out
to determine the vibrational modes of DPPC that are sensitive to
the gel-liquid crystal phase transition occurring at 41°C. Characterization
of the DPPC phospholipids in the liquid crystal state is important
to understanding the permeability of the lipid membrane. After
the phase transition, a noticeable slight shift in the CH2 deformation mode from 1462 cm-1 to 1458 cm-1 occurs which may be explained by a weakening of the dispersion
forces between neighboring phospholipids, allowing the CH2 groups
to vibrate more freely. The second aim of this project is to develop
a broadband coherent anti-Stokes Raman scattering (CARS) optical
trapping system to enable monitoring rapid biological processes.
To achieve this end, the laser conditions necessary to generate
broadband light by the coupling of femtosecond pulsed near-infrared
light into a photonic crystal fiber (PCF) were investigated.
Development of Optical Trapping Raman and Coherent Anti-Stokes Raman Scattering
(CARS) Spectroscopy for Analysis of Phospholipid Vesicles. BETHANY WEISS (Fayetteville State University, Fayetteville, NC, 28301)
DR. JAMES W. CHAN (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Raman spectroscopy
is a powerful technique that is being applied to the study of biological
systems in our lab. Raman spectroscopy is a laser-based method
of chemical analysis that generate vibrational signal from molecular
bonds. There are two overall goals of this project. The first aim
is to obtain the spontaneous Raman signatures of individual optically-trapped
phospholid vesicles. Two types of lipids are analyzed in this experiment,
1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine
(DMPC). Single 0.4 µm diameter lipid vesicles are successfully
trapped in a laser trapping Raman system and their spectral signatures
simultaneously acquired. Additional experiments were carried out
to determine the vibrational modes of DPPC that are sensitive to
the gel-liquid crystal phase transition occurring at 41°C. Characterization
of the DPPC phospholipids in the liquid crystal state is important
to understanding the permeability of the lipid membrane. After
the phase transition, a noticeable slight shift in the CH2 deformation
mode from 1462 cm-1 to
1458 cm-1 occurs
which may be explained by a weakening of the dispersion forces
between neighboring phospholipids, allowing the CH2 groups to vibrate more freely. The second aim of this project
is to develop a broadband coherent anti-Stokes Raman scattering
(CARS) optical trapping system to enable monitoring rapid biological
processes. To achieve this end, the laser conditions necessary
to generate broadband light by the coupling of femtosecond pulsed
near-infrared light into a photonic crystal fiber (PCF) was investigated.
Generation of Theoretical Spectra for Hot Dense Matter. AJIT HIRA
(Northern New Mexico Community
College, Espanola, NM, 87532)
DR. RICHARD W. LEE (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Tritium will
be used as a fuel for the NIF ignition experiments. Understanding
its behavior in various materials is important to evaluate inventory
and to develop safety plans for handling tritiated hardware. Since
tritium monitors will be used for evaluating airborne tritium concentration,
the response of tritium monitor, an ion chamber, was calculated
as a function of distance from the center of the chamber to the
source location. A Cs-137 gamma check source was used to determine
the experimental response of the meter as a function of distance
from the center of the chamber. Cs-137 emits beta radiation (95%
- 0.514 MeV, and 5% - 1.18 MeV; with 0.661 MeV gammas). Its half-life
is about 30.07 years. By correlating a simple relationship between
the tritium energy deposition and gamma energy deposit in the chamber
volume, an external gamma source can be used to both check the
response and calibrate the meter precisely. Also had a brief opportunity
to study the radiation dose-response relationship, primarily for
acute doses, for various species as function of DNA content, number
of chromosomes, body mass, etc. Some discussions were held in the
areas of radiobiology and nuclear medicine.
Generation of Theoretical Spectra for Hot Dense Matter. ELIAS
ALLISON, MATILDA FERNANDEZ, & AJIT HIRA (Northern New
Mexico Community College, Espanola, NM, 87532)
DR. RICHARD W. LEE (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
The focus of
this project is to use computer codes to generate spectroscopic
for data plasmas and for hot dense matter, and to use these theoretical
spectra to interpret experimental results. These theoretical spectra
are important because of their applications in the study of ionized
matter and magnetic fields near the surfaces of the sun and stars,
the origin of cosmic rays, the dispersion and broadening of signals
traveling through interstellar space, the realization of controlled
release of nuclear fusion energy, and the development of new electronic
devices, among others. The computer codes model specified interactions
for elements ranging from Helium to Iron, with a particular interest
in lithium-like, helium-like and hydrogenic ionic species. Some
of the important events included in the model are collisional ionization
and recombination, radiative, bound-free processes, bound-bound
processes, auto-ionization and electron capture. At present the
focus of the project is the design and implementation of a good
dynamic interface to improve the use of existing codes.
MEMS Optical Force Probe. KEVIN LIN (University
of California, Berkeley, Berkeley, CA, 94720)
JACK KOTOVSKY (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
This work seeks
to design small and tunable optical force probes to measure compressive
loads. As the sensor will be placed between two surfaces, a major
goal is to minimize the thickness of the sensor. Optical sensors
based on fiber optic and Micro-electro-mechanical systems (MEMS)
technology allow for small, versatile, and accurate sensors. These
sensors do not use electricity, and offer numerous advantages over
traditional sensors. Fiber Bragg Gratings (FBGs) are treated fibers
that have a periodically varying index of refraction to give a
distinct reflection and transmission spectrum. This spectrum is
dependent on strain, caused either by a transducer attached to
the fiber or thermal expansion. A challenge of this work is to
create a MEMS structure that transduces transverse loads to fiber
strain while compensating for thermal expansion. The limitations
of silicon and the size of the device introduce many challenges.
Finite Element Analysis (FEA) simulates the mechanical and thermal
behavior of the MEMS transducer and its micro-beams to determine
a suitable geometry (i.e. angle, length, and height). Various metal
coatings, solders, and soldering techniques are examined to determine
a repeatable and reliable method for sensor assembly. Groove cross-sections
are optimized for superior fiber to silicon bonding. Novel schemes
assist in the alignment and assembly of the sensor. An optical
force sensor using FBGs has been designed with a total thickness
of 140um (similar in thickness to a fiber optic cable), insignificant
thermal sensitivity, tuneability to different applied pressures,
and mass manufacturability. Its fabrication is currently underway.
Mobile Data Collection Applications: A Proof of Concept. JONATHAN
CHANG (University of California, Berkeley, Berkeley, CA, 94720)
TIM LOWE (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
This project’s
goal is to provide a proof of concept for mobile data collection
applications, and identify the best ways such applications could
be implemented and used. Such an application should decrease the
time and resources users now need to devote to redundant data processes,
and provide an easy of locating and retrieving data at a later
time. The two types of available mobile devices, Personal Digital
Assistants and Tablet Personal Computers, each have their particular
strengths that suggest themselves for certain types of applications.
As such, parallel data collection applications have been developed,
with a common web application for uploading information to the
database. While these aspects have been developed and proven, it
still remains to refine these applications, develop the tables
to hold their data, and field-test with users for their feedback.
Overexpression of human SOST in transgenic mice results in defective patterning
of limb cartilage elements. LEILA
BEACH (Stanford University, Stanford, CA, 94305) GABRIELA G. LOOTS (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Sclerosteosis
is a generalized progressive bone overgrowth disorder due to the
loss of function of the SOST gene product sclerostin. Null mutations
in SOST result in occasional polydactyly and syndactyly along with
a substantial progressive increase in bone density. Accumulation
of abnormal bone mass begins in late childhood and affected patients
display increased bone formation, while bone resorption is undisturbed.
SOST is expressed in osteocytes, the mature metabolic cells in
ossified bone. To investigate the physiological function of the
SOST protein, we have generated several lines of transgenic mice
carrying a ~160kb human SOST bacterial artificial chromosome or
BAC. Transgenic mice overexpressing SOST (hSOSTwt) exhibit a decrease
in bone mineral density in the appendicular and axial skeleton
when compared to non-transgenics from four to six months of age
as evaluated by Dual Energy X-ray Absortiometry (DEXA) and quantitative
computed tomography pQCT. When bred to homozygosity (hSOSTwt/wt)
these animals also show congenital limb defects. Hereditary hand
malformations occur frequently in human populations, therefore
these animals can serve as a model for understanding molecular
perturbations that lead to improper limb patterning. The fore-
and hind-limbs of these animals are severely deformed displaying
a wide range of fused and missing digits as visualized by autoradiography
and pQCT. Since limb development is initiated prior to ossification
of the skeleton, we find SOST to be expressed in the developing
embryo as early as embryonic day 9 (E9), predominantly in the mesenchyme
tissue of the developing limb bud. We have performed a detailed
phenotypic analysis of these transgenic embryos using skeletal
preparations and histology which revealed a defect in cartilage
formation. To investigate whether the limb defect stems from defective
chondrocyte differentiation, proliferation, or apoptosis we set
out to examine limb sections by in situ hybridization. We identified
cDNA clones to generate antisense RNA probes for Fgfr1 (expressed
in distal proliferating chondrocytes), Bmp7 (columnar proliferating),
Fst and Tgfß2 (early hypertrophic), Bmp2, and Tgfß3 (hypertrophic
cells), and Spp1 (terminal hypertrophic). These markers represent
distinct stages in the chondrocyte differentiation program, and
misexpression of these markers revealed by in situ hybridization
will indicate cell types that may show excessive proliferation
or apoptosis.
Policy Analysis: Rapid Response Vaccine Development for Emerging and Emergent
Infectious Diseases. CATHERINE COLAIANNI (Duke University, Durham, NC, 27708) THOMAS BATES (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Despite billions
of dollars spent in research and development, the U.S. is alarmingly
under-prepared to defend against biological warfare. This is most
notable when considering the availability of biodefense vaccines.
Vaccine production facilities are disappearing, and the production
methodology employed in most cases is slow, expensive and outdated.
Additionally, there is no comprehensive capability or even a strategy
to develop and produce vaccines rapidly as part of an emergency
response to a new or emerging pathogen. To explore the current
state of vaccine production and to consider possible new directions
to enhance our national posture, we undertook a policy analysis
starting with an in-depth review of the historical vaccine development
cycle for Bacillus anthracis,
including the time requirements and government funding. Next, we
made simple projections for a similar path to develop vaccines
for other NIAID Category A Priority pathogens. Finally, options
were explored for new research and development directions (5 to
10 year timeline) to support a rapid vaccine development process
amenable to emergency use. The long-term solution was assessed
to be an end-to-end "pipeline approach" whereby either
synthetic subunit or attenuated vaccines could be rapidly produced
'on-demand'; however, considerable research is still required for
methods to rapidly identify virulence factors and antigenic regions.
Qualitative Testing of Social Network Analysis Biowarfare Taxonomy: An Analysis
of LLNL Open Source Publications. LIRAN
GOLDMAN (University of California, San Diego, La Jolla, CA, 92093)
DEBORAH YARSIKE BALL AND DALE K. BREARCLIFFE (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
The Dynamic Network
Engineering Group takes a network-centric approach to discover
and characterize organizational expertise and relationships of
state and non-state actors intent on creating and using weapons
of mass destruction (WMD). This approach utilizes a taxonomy that
can identify and extract key actors from large, unstructured data
sources. In this project, a taxonomy was developed and tested on
a known entity: Lawrence Livermore National Laboratory (LLNL).
The goal was to discover and qualitatively describe the results
of a specific taxonomy when combined with the dynamic network analysis
methods. The data used in this test analysis include a list of
Livermore Laboratory employees who have a pager assigned to them,
online versions of LLNL’s Science & Technology Review (S&TR),
and a potential biowarfare taxonomy. After the S&TR issues
were downloaded, the data were uploaded and processed in Automap,
a program capable of extracting and analyzing computer based text
by creating links among words then constructing a network. Next,
the words of interest were extracted from the S&TR articles,
and evaluated in Organization Risk Analyzer (ORA), a program capable
of statistically analyzing dynamic networks. The analysis completed
by ORA on this dataset revealed some key findings: the years 2003
and 2004 were prominent for biology related publications. Also,
pathogens and anthrax were consistently the top areas explored.
Follow-up analysis of these results indicates that this process
is successful at singling out pertinent actors, but the results
should be viewed with caution. A few drawbacks include Automap’s
failure to extract variations of words the program is instructed
to locate. Additionally, not all of the relationships established
by Automap are valid due to its inability to distinguish between
unrelated, yet adjacent articles. Furthermore, reporters who wrote
the publications used in this test case became part of the data
set. Also, the inclusion of projects and people is not a complete
representation of ongoing research at LLNL. This latter issue is
somewhat mitigated when examining external organizational expertise
and relationships because the publications assessed are usually
authored by the researchers themselves. These matters will be considered
when applying this process to other datasets.
Regional Assessment of CO 2 Sources and Sinks for the Indian Subcontinent. YOLANDA PRICE (Central State University, Wilberforce, Oh, 0) JULIO FRIEDMANN (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Carbon dioxide
(CO 2)
is the primary anthropogenic greenhouse gas. Developing countries
are expected to substantially add to future greenhouse gas emissions.
In particular, India’s CO2 emissions
are expected to increase 70% by 2025. Geologic carbon capture and
storage (CCS) offers a way to reduce CO 2 emissions. Our study used GIS to answer two questions. 1. Where
are the major CO2 sources, sinks and risks in South Asia? 2. Where should geologic
CO 2 sequestration
efforts be focused in South Asia? To improve this assessment we
augmented the International Energy Agency’s GHG database for South
Asia by locating 1/3 of the region’s large stationary CO2 sources
with emissions > 0.1 MM t CO2/y.
The Efficacy of the National Ignitions Facility's Ergonomic Program. NAOMI SHAH (University of California San
Diego, La Jolla, CA, 92092)
STEVEN MCCONNELL (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Ergonomic injuries
have become an increasing concern for office workers and their
employers due to the rise in computer-based work. These injuries,
as with all chronic injuries, are most prevalent in the older members
of the work force due to a longer exposure to chronic insults to
their bodies. In 2005, over half of the recorded illness/injury
cases at the National Ignitions Facility (NIF) at Lawrence Livermore
National Laboratory (LLNL) were ergonomic cases. In order to reduce
the number of such cases and their associated costs, NIF has implemented
an ergonomic program in which the goal is to evaluate their 1,200
employees. The current process of creating a list of employees
who need an evaluation, making an appointment with the employees,
performing the evaluation, and following up afterwards proved to
have some problems which inhibit efficiency. To enhance the process
of forming a list of employees for evaluations, a new database
has been developed and is being tested. This allows the evaluator
to receive daily updated lists. In order to easily set up appointments
and yield a larger response rate, it was found that a Meeting Maker
proposal followed by an Email works the best. The evaluator uses
the NIF Comfort Survey to help asses the employee’s work space;
this survey proves to be sufficient in identifying the needs of
the employee. Overall, the ergonomic program has made a good start
in preventing further ergonomic injuries, and with implementation
of the new recommendations, will prove to be an efficacious program.
The Laboratory Assessment Worksheet—A Risk Comparison of Biological and Chemical
Hazards in the Laboratory. REBECCA
WILLIAMSON (University of Virginia, Charlottesville, VA, 22556) GERALD SCHWEICKERT (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Today’s hazardous
world demands safe work practices. An employee’s risk of injury
and infection increases significantly when he handles sharps. To
assess sharps use and compliance with correct safety controls and
practices, the author generated a survey form. This form was based
on current safety standards and used to conduct face-to-face interviews
of Lawrence Livermore National Laboratory (LLNL) personnel who
were using biological materials and sharps in research projects.
At LLNL, current safety standards are summarized in what is known
as the Environmental Safety and Health (ES&H) Manual. Close
scrutinization of the ES&H manual confirmed consistency with
the current sharps use standards. The Occupational Safety & Health
Administration (OSHA) Bloodborne Pathogens Standard mandates that
employers maintain a sharps injury log. The survey was designed
to determine if any discrepancies between the number of sharps
injuries sustained and those reported existed. However, the LLNL
sharps injury log was not currently available but will be available
in the future, and therefore such comparisons were not performed
as part of this analysis. Twenty percent of the facilities using
sharps at LLNL were evaluated. During the assessments, almost sixty
percent of the labs had an observable sharps safety hazard. These
safety breaches fell into one of the following three categories:
improper recapping technique, presence of an exposed or improperly
discarded sharp, or overfilled sharps container. Nearly twenty
percent of the individuals interviewed either had injured himself
with a sharp or knew of someone affiliated with his particular
lab that had been injured. Seventy-five percent of the reported
injuries occurred in a BSL-2 lab. Most researchers at LLNL use
scalpels and needles. Half of the researchers reuse their sharps,
a practice that should be avoided. The statistical results of the
surveys alerted safety personnel to the need for sharps training
and further evaluation of sharps use at LLNL.
Tritium diffusivity in metals; response of a tritium monitor to Cs-137 gammas;
dose-response relationship function of species mass, DNA content
and chromosomes. CHRISTOPHER COPELAND (Morehouse College, Atlanta, GA, 30314) MICHAEL SINGH (Lawrence Livermore
National Laboratory, Livermore, CA, 94550)
Tritium will
be used as a fuel for the NIF ignition experiments. Understanding
its behavior in various materials is important to evaluate inventory
and to develop safety plans for handling tritiated hardware. Since
tritium monitors will be used for evaluating airborne tritium concentration,
the response of tritium monitor, an ion chamber, was calculated
as a function of distance from the center of the chamber to the
source location. A Cs-137 gamma check source was used to determine
the experimental response of the meter as a function of distance
from the center of the chamber. Cs-137 emits beta radiation (95%
- 0.514 MeV, and 5% - 1.18 MeV; with 0.661 MeV gammas). Its half-life
is about 30.07 years. By correlating a simple relationship between
the tritium energy deposition and gamma energy deposit in the chamber
volume, an external gamma source can be used to both check the
response and calibrate the meter precisely. Also had a brief opportunity
to study the radiation dose-response relationship, primarily for
acute doses, for various species as function of DNA content, number
of chromosomes, body mass, etc. Some discussions were held in the
areas of radiobiology and nuclear medicine.
