Nuclear Science: The Feasibility of Using a Particle Accelerator to Produce Tritium

Published by the Government Accountability Office on 1990-02-02.

Below is a raw (and likely hideous) rendition of the original report. (PDF)


                  I’rlittd   States   Gent~ral Accountit~g   Office

GAO               Ih-icf’ing Report to Congressional
                  Reques t,ers

February   1990
                  NUCLEAR SCIENCE
                  The Feasibility of
                  Using a Particle
                  Accelerator to Produce
United States
Washington,     D.C. 20648

Resources, Commanity,        and
Economic Development         Division



The Honorable            Brock Adams
United States            Senate
The Honorable  Sid Morrison
House of Representatives
In your January 30, 1989, letter,                  you raised       questions       about
the potential        for the U.S. Department             of Energy (DOE) to
produce tritium,         a critical      material       needed for nuclear
weapons, using a linear             accelerator      rather      than a react0r.l
Specifically,        you asked us (1) if the option                 of using an
accelerator       as a tritium       production       facility      appears
feasible;      (2) if DOE adequately            considered       particle
accelerator      technologies        during     its examination          of future
tritium     production      options:     and (3) what cost,             safety,     and
environmental        advantages      accelerator        production        of tritium,
if feasible,       might have over production                by a nuclear
As part of its national          defense activities,         DOE is
responsible       for producing     tritium,     a perishable     gas used in
nuclear     weapons.      To date, nuclear       reactors    are the only
successfully        demonstrated    method for producing        the
quantities      of tritium     needed.       However, DOE's aging defense
production      reactors     have been shut down due to operational
safety     concerns,     and the timetable       for resuming tritium
production      is uncertain.
In December 1987, the Congress requested          that the Secretary
of Energy prepare a report      on acquiring     replacement
reactors.    In January 1988, the Secretary         asked the Energy
Research Advisory    Board2 to assess four different          reactor
technologies   for the production    of tritium.        On August 8,
1988, the Secretary    of Energy issued a report         to the

'A linear    accelerator                   is a device that uses basic laws of
electromagnetism       to               increase  the motion energy of charged
2The Energy Research Advisory         Board is an independent
review board appointed       by the Secretary     of Energy to
provide    input to DOE on technical       issues such as
technologies     for tritium   production.
Congress recommending          that DOE proceed        on an urgent
schedule to construct          two new reactors        for tritium
In March 1989, however, scientists        at DOE's Brookhaven and
Los Alamos National     Laboratories   issued a report     in which
they concluded     that due to technological     advances,   tritium
could be produced using an accelerator.          The report
contained   preliminary    designs for a tritium-producing
accelerator    to be located    at DOE's Hanford Reservation,        near
Richland,   Washington.
In summary,      we found     the   following:
--   Accelerator       production      of tritium     appears technically
     feasible.        However, an accelerator          with the operating
     characteristics         necessary    for tritium      production    does
     not currently        exist.    Engineering       development     is needed
     to design and demonstrate            the major components,         optimize
     reliability       and efficiency,         and assure sustained
     operability       of an accelerator         with the parameters
     required      for tritium     production.
     The congressionally        mandated evaluation           of new tritium
     production     reactors    did not require           DOE to consider
     technologies      other than nuclear          reactors.     However, DOE
     looked briefly       at alternatives,         including    accelerator
     systems.      DOE concluded      that the alternative
     technologies      were not sufficiently            mature to provide    new
     tritium    production    capacity      within      the needed time
     frame, but it is currently            reviewing       the accelerator
     concept in more detail.
--   When compared with reactor             production,      accelerator
     production       of tritium      presents      fewer safety     and
     environmental        concerns.       Further,      an accelerator     could
     have cost and/or schedule advantages                  over a new
     production       reactor.      In addition,        an accelerator     could
     be sized to meet a specific              tritium     need and then
     upgraded with relative            ease should the need for tritium
     increase.        However, because of the amount of electricity
     required       by a large tritium-producing            accelerator,     a new
     electric       generating   plant may be needed.             If this is the
     case, then the accelerator              advantages     would be partially
     offset      by the environmental          consequences     associated     with
     fossil      fuel or nuclear       power electric       generating
Section     1 contains background          information     on tritium
production,     DOE's consideration           of producing    tritium     using
an accelerator,      and our objectives,        scope, and methodology.
Section   2 provides       details     about the concept of a tritium-
producing    accelerator       and the significance       of achieving
stated parameters        through     remaining  engineering     and
development.      Section       3 compares accelerator      production of
tritium   with reactor        production.

To assess the feasibility         of using an accelerator                to produce
tritium,    we interviewed     physicists          and other scientists--at
U.S. and Canadian national           laboratories--with             expertise     in
one or more aspects of accelerator                 technologies.         We asked
them to identify       the potential        advantages         and/or
disadvantages     of using an accelerator              to produce tritium,
compared with using a nuclear             reactor.         In addition,        we
discussed    these issues with DOE officials                   in Washington,
D.C., and DOE contractor         officials         in Richland,        Washington;
Los Alamos, New Mexico; Upton, New York; and Newport News,
Virginia.      We also interviewed          officials        of the Bonneville
Power Administration,        which provides           electric      power to the
Hanford Reservation --a proposed site for an accelerator--to
discuss   the cost and availability              of electric        power.      Los
Alamos officials       reviewed the technical              information       in the
report.     However, as you requested,               we did not obtain
formal agency comments on this report.                    Our review was
conducted between February and August 1989, in accordance
with generally     accepted government             auditing      standards.
As arranged with your offices,            unless you publicly       announce
its contents      earlier,     we plan no further     distribution     of
this report     until      30 days from the date of this letter.            At
that time, we will          send copies of this report        to the
appropriate     House and Senate committees:          the Secretary      of
Energy: and the Director,          Office    of Management and Budget.
Copies will     also be made available         to other interested
parties     who request them.
Should you have questions     or need additional               information,
please contact   me on (202) 275-1441.      Major             contributors       to
this report   are included  in appendix I.

Director,     Energy /issues

LETTER                                                            1
               Reactor Production       of Tritium
               Particle    Accelerators
               DOE's New Production       Reactor Study
               Objectives,    Scope, and Methodology
             AN ACCELERATOR                                      11
               The Concept:     How Tritium    Would Be
                  Produced in an Accelerator                     11
               Engineering    Development    Is Needed to
                  Overcome Accelerator      Uncertainties        14
             NEW TRITIUM PRODUCTION                              19
               Accelerator     Would Avoid Safety and
                  Environmental     Concerns Associated
                  With Fission     Reactors                      19
               Potential    Cost and Schedule Advantages
                  Depend on Engineering      Development        21
               Electricity     Requirements    Are a
                  Potential    Disadvantage                     24
               Downsized Accelerators       Offer
                  Advantage of Flexibility                      25
             REPORT                                             28
  2.1      Components of the Tritium-Producing
             Accelerator                                        12
  2.2      Target System, Showing        Sweeper Magnet   and
             Other Components                                   13
  2.3      Cross   Section   of Target    Tube                  14

DOE    Department    of Energy
ERAB   Energy Research Advisory        Board
GAO    General Accounting      Office
Gel'   Giga electron    Volt
RCED   Resources,    Community,     and Economic
          Development   Division
                                        SECTION 1
        The U.S. Department         of Energy (DOE) is responsible              for
researching,        developing,     and testing    nuclear    weapons for the
Department       of Defense.       These responsibilities        include      producing
certain    critical      materials    required    for the weapons.          One such
material     is tritium,       a gaseous isotope       used to enhance the
explosive      power of nuclear       warheads.      Tritium   is radioactive,          and
about 5.5 percent          is lost each year through natural             decay.      Because
of this loss, existing            weapons must be resupplied          periodically       with
tritium    in order to maintain          their  readiness.
       In the 195Os, DOE began producing          tritium     in nuclear    reactors
located     at the Savannah River Site,       near Aiken,       South Carolina.
Concerns about the operational         safety    of those reactors       led DOE to
shut them down in 1988, and it is uncertain               when they will      resume
production.       Following a congressional       mandate to study and report
on new defense materials      production      reactor     capacity,   in August
1988 DOE recommended construction          of two new defense materials
production     reactors.
        Tritium     is a form of hydrogen that occurs naturally          in only
very minute quantities:         hence, it must be ?nanufactured.ll          Ordinary
hydrogen,       such as that found in drinking      water,    is a simple element
whose atomic nucleus consists          of a single   proton.1     If a neutron       is
added to the nucleus,        the ordinary   hydrogen becomes deuterium;          if
another neutron        is added, the deuterium     becomes tritium.        Thus,
tritium       is a hydrogen atom whose nucleus consists         of one proton and
two neutrons.
         Currently,     the only operable      reactors    capable of producing       the
necessary      quantities    of tritium     are the heavy water reactors2
located      at DOE's Savannah River Site.            These reactors      employ
uranium fuel elements          interspersed     with aluminum tubes containing
lithium.       Neutrons are generated         by the fission,       or splitting,    of
the uranium atoms in the fuel.              Some of these neutrons          are absorbed
by the lithium,         thus forming tritium.         Periodically,     the lithium
tubes are replaced,         and tritium     is extracted      from those removed
from the reactor.

lProtons    are particles  with a positive    electric   charge.   Atomic
nuclei   are composed of one or more protons        and, with the exception
of ordinary     hydrogen, one or more electrically      neutral  particles
called   neutrons.
2Heavy water is water that has been enriched  with deuterium.       The
reactors use heavy water to cool and moderate the nuclear     reaction.
       First    developed    in the 1930s for research   purposes,  particle
accelerators        are devices that use basic laws of electromagnetism
to increase       the motion energy of charged particles      such as
protons.       The charged particles     gain energy by passing through      a
series      of electrically    charged tubes.
        DOE has funded the construction                and operation           of a number of
particle      accelerators     under its high-energy                physics     and nuclear
physics     research     programs,       for example, at the Fermi National
Accelerator       Laboratory,      near Chicago,         Illinois,         and at the Stanford
Linear     Accelerator      Center,      near Palo Alto,           California.       According
to DOE and accelerator           facility     officials,           experiments      conducted
using    DOE's high-energy         physics    and nuclear           physics     accelerators
have resulted        in many important        discoveries           related     to the
structure      and properties       of atomic nuclei             and subnuclear
         Accelerator   designs vary, but all employ certain               principal
components:     a source      of particles    to be accelerated,          a beam of
accelerated    particles     going in a single       direction,       and a target.
In the Fermi National        Accelerator     Laboratory's       main accelerator,
the beam is accelerated         around a circular       tube about 4 miles in
circumference.       As the name implies,       the Stanford         Linear
Accelerator    Center's     accelerator    is a straight        (linear)     tube about
2 miles      long.

         Proposals    to use accelerators        for tritium      production      have been
made since    the 195Os,      although      no accelerator      has been constructed
for this   purpose.   In      a March 1989 report,          scientists      at DOE's
Brookhaven and Los Alamos National               Laboratories       noted that
extensive      development    activities      for the Strategic         Defense
Initiative      in the 1980s had produced major advances in accelerator
technology.        The report    concluded     that accelerator         production    of
tritium     is feasible    and contained       preliminary      designs     for a
tritium-producing        accelerator      to be located       at DOE's Hanford
Reservation,       near Richland,       Washington.

              Law 100-202,     December 1987, required   the Secretary    of
Energy     to       an acquisition
                  prepare              strategy  for new nuclear
production  reactor   capacity.     The report  was to be submitted    to the
Committees  on Appropriations      and on Armed Services    in the Senate
and the House of Representatives       by May 1, 1988.
       The Secretary   requested     the Energy Research Advisory    Board
(ERJ'JB), an independent     review board appointed    by the Secretary,   to
assess   four reactor    technologies.     Among other things,   the
Secretary     specifically    requested   ERAB to assess (1) DOE's proposed
selection     criteria,    (2) the adequacy of each technology       to meet the
criteria,     and (3) the potential     technical  and schedule    risks,
costs,    and benefits     of each of four proposed nuclear     reactor
       DOE's report    to the congressional      committees    was issued in
August 1988.     The report    contained     the results    of the technical
evaluation   of four reactor      technologies    under consideration        and
recommended construction       of a new heavy water production           reactor          at
the Savannah River Site and a gas-cooled            reactor   at the Idaho
National   Engineering    Laboratory,     near Idaho Falls,      Idaho.4
Consideration    of Accelerator
Production    of Tritium
       Although     the congressional        mandate      to evaluate     new tritium
production     reactors     did not require       DOE     to consider     technologies
other than nuclear         reactors,      DOE's ERAB      looked briefly      at
alternative      technologies      with potential         for tritium     production.
One alternative        was accelerator       production       of tritium,     a subject   of
research     at several      DOE facilities.
       In February       1988, ERAB officials       met to receive       presentations
on alternatives        for new defense production         reactor      capacity.      Los
Alamos and Brookhaven officials            presented    the concept of
accelerator     production     of tritium     to ERAB. Officials           of the two
laboratories      stated that their       presentations      to ERAB lasted         about 1
hour each and that ERAB members did not request                   follow-up
information     from either.        Los Alamos officials        stated that
accelerator     technology     was not the ERAB members' primary                area of
expertise.      In addition,       Brookhaven officials        noted that their
presentation      occurred    during the last part of the ERAB review and
that ERAB was operating          under time constraints.
        ERAB concluded        that accelerator       technology     was not
sufficiently          mature to provide     new tritiurn     production       capacity
within      the needed time frame.          However, at DOE's request,              ERAB is
currently        evaluating     accelerator    production      of tritium      using the
same criteria          used to evaluate     the reactor      technologies.          ERAB was
specifically          asked to determine      how soon an accelerator           could meet
national       tritium     needs and at what cost.          A final     report    is
scheduled         for February     1990.

3The four technologies      were the heavy water reactor;    light                water
reactor;  high-temperature,     gas-cooled reactor:  and liquid                  metal
4See our report   entitled    Nuclear Science:     Better    Information
Needed for Selection      of New Production   Reactor     (GAO/RCED-89-206,
Sept. 21, 1989).
        The Los Alamos/Brookhaven        report5      on accelerator      production       of
tritium     resulted    from coordinated      research     efforts     by the two
laboratories       and the Westinghouse       Hanford Company, the operating
contractor      for DOE's Hanford Reservation           facilities.       The Los
Alamos and Brookhaven laboratories              have continued       to refine     the
accelerator       concept and explore      alternative       accelerator     design
parameters      since the report     was prepared.
        In a January 30, 1989, letter,    Senator Brock Adams and
Representative     Sid Morrison   asked us about accelerator production
of tritium.      Specifically,  the requesters   asked us if
       --   the option   of using an accelerator            as a tritium      production
            facility   appears feasible;
       es DOE adequately        considered   particle       accelerator
            technologies     during    its examination       of tritium      production
            options:     and
       --   production     of tritium     by an accelerator,         if feasible,     would
            provide    cost,  safety,     and environmental         advantages    over
            production     by nuclear     reactors.
         To assess the feasibility             of using an accelerator         to produce
tritium,     we interviewed         scientists      with expertise      in one or more
aspects of accelerator            technologies.         To identify     such experts,
we depended on referrals             from (1) the scientists          at Los Alamos who
prepared     the March 1989 report             and (2) officials      we contacted      at
the National        Academy of Sciences,          the Office      of Technology
Assessment,       and the National          Science Foundation.         In asking for
referrals,      we sought a balance of opinions:                that is, we were
interested      in talking      to scientists         who could point     out potential
problems or uncertainties              with using an accelerator          as well as
those who could identify             potential      benefits.      Because the
scientists      were not selected           randomly,    however, their      views do not
necessarily       represent     the views of all scientists            with expertise      in
accelerator       technologies.
        We asked the scientists            about the theoretical        aspects of
accelerator       production      of tritium       as well as about the uncertainty
associated      with the engineering,            construction,     and operation    of a
tritium-producing          accelerator      facility.       We also asked the
scientists      to identify       the potential       advantages    and/or
disadvantages        of using an accelerator            to produce tritium     compared
with using a nuclear           reactor.      We were assisted       in these activities

5Accelerator      Production     of Tritium       (APT) Executive      Report,    Mar.
by Dr. George Hinman,           a nuclear     physicist      at Washington       State
       We discussed       these issues with officials                 at (1) the DOE
Operations       Office   in Richland,          Washington,     which oversees the
Hanford Reservation;            (2) Los Alamos National              Laboratory;       (3)
Brookhaven National           Laboratory:        (4) the Westinghouse            Hanford
Company, the contractor             that operates        the Hanford facilities;             and
 (5) DOE's Continuous           Electron      Beam Accelerator         Facility,      in Newport
News, Virginia,         a particle       accelerator       currently      under
construction.          Because a tritium-producing               accelerator       would
require      an enormous supply of electricity--potentially                        affecting
its cost, reliability,             and/or environmental            impact relative         to a
reactor's     --we interviewed         officials      of the Bonneville           Power
Administration,         in Portland,        Oregon, to discuss          the cost and
availability        of electric       power.
      To determine     the extent to which DOE considered       accelerator
production   of tritium,     we interviewed    officials  at Brookhaven and
Los Alamos National       Laboratories,    and the Westinghouse   Hanford
      Our review       was conducted between February               and August      1989,    in
accordance with        generally   accepted governmental             auditing

                                       SECTION 2
                            FEASIBILITY OF PRODUCING
                          TRITIUM USING AN ACCELERATOR
        The consensus of the experts        we contacted      is that accelerator
production     of tritium     is a sound concept.         However, an accelerator
with the parameters,        or operating    characteristics,        necessary for
tritium    production     does not currently     exist.      Engineering
development     is needed to design and demonstrate             the major
components,     optimize    reliability    and efficiency,        and ensure
sustained     operability     of an accelerator     with the parameters
required    for tritium     production.
        As noted in section        1, tritium      is produced when lithium          atoms
absorb free neutrons.           Free neutrons        are therefore       a key
"ingredientVl      for producing     tritium.        In concept,     the accelerator
would be used simply to generate               the needed free neutrons.           Once
generated,      the free neutrons         would interact        with the lithium
contained     in the target      assembly,       in much the same fashion         as in a
nuclear    reactor.       Also, as in reactor          production,     the target    pins
containing      the tritium     would be removed periodically              and the
tritium    extracted.
       The conceptual   tritium-producing         accelerator      described      in the
March 1989 Los Alamos/Brookhaven           re ort is designed to produce 100
percent    of tritium  goal quantities.       P The accelerator          consists    of
two major systems:      a linear      accelerator     (linac)     and a target
assembly.     Since publication       of the report,       Los Alamos officials
have proposed modifications         to the original        design;   however, the
underlying    concepts have not changed.           A detailed      description      of
the systems and how they would work follows:
The Accelerator
       The accelerator        would be used to generate        a high-energy       proton
beam-- essentially,        a lVstreaxnfiV of protons   that strikes       the target
assembly at nearly         the speed of light.        As currently
conceptualized,        the accelerator      would consist     of five principal
components--ion        source,    radio frequency     quadrupoles,      funneling
device,    drift    tube linac,      and coupled cavity     linac--arrayed        as in
figure   2.1.    Housed in a concrete         tunnel,    the accelerator       would be
about 3,450 feet long.

lThe quantity    of tritium needed to meet all national       defense needs
is referred   to as the "goal amount."    A tritium-producing       facility
may be described    by the "percent  of goal" it is capable of producing.
      Fisure        2.1:            Comnonents         of the      Tritium-Producina                 Accelerator

Ion Sources

                                                                            Coupled   Cavity Linac

                                I                            Drift Tube Linac
              Radio Frequency       Quadrupoles

      Source:           Los Alamos                National     Laboratory.
             For the accelerator        to produce the goal amount of tritium,         the
     proton beam must have a very high current.              This high current
     necessitates        that two ion sources and radio frequency          quadrupoles
     be used at the initial          stage of the accelerator.        The ion sources
     strip     electrons     from hydrogen atoms, leaving      single   protons   as the
     particles       to be accelerated.       The protons are propelled       out of the
     source chamber and into the radio frequency              quadrupoles.
              Each radio frequency        quadrupole    would arrange the protons
      into bunches and accelerate            them.    Once the two beams are created
      and initially       accelerated,     they would be merged in a section      of the
      accelerator      called    the funnel,     which would use magnetic   elements to
      combine them.         The number of proton bunches, and thus the current,
      in the combined beam would be twice that of each beam entering                 the
      funnel.       The ion source,     radio frequency      quadrupoles, and funnel
      total    about 56 feet in length.
             The next component,     the drift    tube linac, would further
      accelerate    the protons    and thus add power to the beam. About                                           167
      feet long, the drift      tube linac     is a necessary  intermediate
      component required      to raise the energy of the protons           so they                                 can
      be successfully    accelerated     by the coupled cavity      linac.
             The coupled cavity     linac   is the last component of the
      accelerator    system.    Electron    tubes called   klystrons      would be used
      to input power to this linac using the designated              radio frequency.
      The coupled cavity     linac,    about 3,225 feet long, would consist            of a
      series of identical      components,     which would successively        accelerate
      the protons    to a very high energy level        and thereby     increase    the
      beam power to about 400 megawatts.

The Target     Svstem
       The target    system would consist     of mVsweeper88magnets and two
target   assemblies.      The design calls     for two target    assemblies   so
that the accelerator       could continue   tritium   production     with one
target   while the other target      is being replaced.
        Between the end of the coupled cavity         linac   and the target,       a
vacuum tube would contain        a device for switching       the beam from one
target    to the other.     As the beam would approach the target             area,
it would be "defocused II to strike        the target    assembly.      The
original     Los Alamos/Brookhaven     design called      for a "sweeper
magnet,"    which would sweep the beam back and forth            horizontally
across the target,      as shown in figure     2.2.
Figure 2.2:      Taraet   Svstem,    Showina      Sweeper Maqnet   and Other
                                                                   Target Tubes

                                      Sweeper   Magnet

Source:      Los Alamos   National    Laboratory.
        Each target    assembly would be made up of about 105 tubes,         each
about 1 foot in diameter        and about 9 feet high, contained      in a
stainless    steel vacuum vessel.      The tubes would be placed upright
in a matrix     arrangement,    about 15 or more tubes across and about 7
deep.     Each tube would contain     570 hollow pins,     of which two-thirds
would be filled      with lead and one-third    with lithium     (see fig.
2.3).     The tubes would be cooled with water,      each having its own
supply line to the bottom of the tube.          The water would circulate
upwards and exit via a line at the top of the tube.

Fisure      2.3:    Cross    Section    of Taraet    Tube

             Top View
                                                            Pressure Tube

                                                            Lead Pin

                                                            Lithium   Pin

Source:        Los Alamos National        Laboratory.
        The protons   striking   the face of the assembly would collide
with lead atoms and produce neutrons           and other high-energy
particles.      These particles     would interact    with other lead atoms to
produce still      more neutrons    in a multiplier    effect,  so that
ultimately     many neutrons    would be generated     from a single    proton-
lead collision.
        Many of the neutrons     would eventually       be captured     by the
lithium,    which would then be converted        to tritium       and helium.      The
first    two rows of tubes,     which    would experience      the  highest   rates
of lithium     conversion,    would be removed after       about 6 months of
operation.      The remaining     rows would be removed annually.            After
the removal of the tubes from the target,             the tritium      pins would be
separated    from the lead pins and the tritium           extracted     using the
Savannah River      Site standard     process.   The lead would be disposed
of   as waste.

        During our review,         we noted several       uncertainties     about the
ability       of the tritium-producing        accelerator       in the Los
Alamos/Brookhaven          conceptual    design to achieve the stated design
objectives.          If these parameters      cannot be achieved through
engineering        development,     then they would have to be changed.             It  is
likely      tha't such changes would increase           the capital     and/or
operating        costs of an accelerator       capable of producing         100 percent
of tritium        goal quantities.
          The major     uncertainties     are

      --   the power efficiency      factor,  that is,            the quantity    of power
           delivered   to the target     compared with            the quantity    of power
           entering  the accelerator:
      --   the ability   of the accelerator       to operate at a high power
           level without    "activating    II the components  (activation
           occurs when a portion        of the beam strays   and hits the
           accelerator   walls,    causing them to become radioactive):
      --   the   funneling       process,    which      has not been demonstrated:        and
      --   the neutron yield    factor,     that is, the number of free
           neutrons   in the target     assembly produced by each proton                  in
           the accelerator   beam.
      A discussion           of these   uncertainties       and their   impacts   follows:
Power Efficiencv       Factor
for Conceptual       Accelerator
May Be Owtimistic

        The power efficiency         factor    of a tritium-producing       accelerator
is probably       the most significant         of all uncertainties       because of
its effect      on capital    and operating        costs.     For the Los
Alamos/Brookhaven        accelerator       design,   the electric      power input
system     represents    about 60 percent         of the accelerator's      estimated
capital     cost, and electric        power consumption        represents   about 60
percent     of the estimated       annual operating        costs.
        The initial      design presented     by the Los Alamos/Brookhaven
report      estimated    the efficiency    factor    at 54 percent.       According to
the report,        this design would require       about 746 megawatts of
electricity;         at an efficiency   factor    of 54 percent,     about 400
megawatts       would enter the beam. An estimated            400 megawatts would
be necessary         to produce the required      1.6 billion    electron    volt
 (GeV) proton beam.2           The 1.6 GeV beam deposited       on the lead/lithium
targets      is expected to generate       enough free neutrons        to produce the
goal amount of tritium.
       However, the 54 percent      efficiency      factor  may be optimistic.
One expert we talked      with told us that a 40 percent         efficiency
factor   should be readily     achievable,      but raising   it to 50 percent
or higher would be more difficult.             The Los Alamos/Brookhaven
report   acknowledged   that due to the need for efficient             conversion,
development    of more powerful     klystron     tubes and power conversion
components    will  be needed.

2An electron     volt is a unit        of measure that describes     the amount of
energy   acquired    by a particle          (such as a proton) as it moves across
an electric      potential       of 1 volt.

        The cost impact of the efficiency           factor   may be illustrated     by
lowering    the 54 percent        estimate   to 40 percent.      At a 40 percent
efficiency     level,     about 1000 megawatts of electricity          (rather  than
746 megawatts)        would be required      to provide    400 megawatts of power
to the target.         Using the same unit costs estimated           by the Los
Alamos/Brookhaven         report,    we estimated   annual operating      costs would
increase    by about $53 million.3           In addition,    capital   cost would
increase    due to the need for additional            power input equipment.
New Concewtual     Desian Mav
Alleviate  Activation     Concerns
       The amount of radioactivity       created   in the accelerator
components is important     because it can affect        costs.    If the
components become highly      activated,     remote maintenance,      rather   than
hands-on maintenance,     would be required       as a safety   precaution.       In
addition,   over the life   of the accelerator,       excessive    activation
could necessitate   replacement      of many of the components.          In both
cases, costs would increase.
       The problem arises   from the effects         of a small number of
protons that travel     down the linac outside         the main proton beam.
If too far from the beam, these lVhalol@ protons             can be absorbed in
the parts of the structure       in which the beam travels         and make
those parts radioactive.        An official      at Los Alamos told us that
not more than one proton in a million            can strike    the walls of the
linac   in which the beam travels        if activation      of the accelerator  is
to remain at a tolerable      level.
        Two potential    solutions    to the activation     problem that do not
involve    changing the accelerator's        operating   parameters    are (1)
placing    llscrapersVl along the beam that would absorb the proton
particles     on the outer edge of the halo and (2) placing            removable
covers on critical       parts or components.        The scrapers    or the covers
would be replaced       as necessary,    with the discarded       ones becoming
waste material.
       Los Alamos officials         have proposed a design modification              in an
effort    to alleviate      the activation     problem.      The new design employs
a larger    bore (that is, a tube with a larger              diameter)     for the beam
to travel    in, thus increasing         the distance     between the halo and
tube walls.       This design modification         involves     halving    the beam's
radio frequency        and replacing     the permanent quadrupole          magnets,
which could suffer        radiation     damage, with electromagnets.             By
making these modifications,           Los Alamos officials         believe    that only
1 in every 10 million          protons will    reach the accelerator          walls.

3GA0 computation     based on 32 nils          (3.2 cents) per kilowatt   over 273
days (three-quarters      of a year).          The Los Alamos/Brookhaven   March
1989 report   estimated    power costs         at 32 nils  (3.2 cents) per
kilowatt  hour.
        Although     increasing      the size of the bore through which the
beam travels       would require        a corresponding    increase in linac     size,
a LOS Alamos       official     told us that these modifications        would have
little   effect     on cost and schedule.           However, the modifications       may
not entirely       eliminate      the need for remote maintenance       operations.
Funnelina Device         Has Not
Been Demonstrated
        Funneling     two separate    positively       charged,  high-current     beams
together    to produce a single         combined beam is a new technology
that has not been demonstrated.               Funneling     is necessary    because of
the large      amount of current      required      in the beam as it hits the
target.     The accelerator       designers      believe    that it would not be
possible    to keep a single       high-current        beam from spreading      apart
too much while at a relatively             low energy level.        Consequently,      to
avoid the beam-spreading          problem,     plans are to use two low-energy
systems,    each of which will        provide     half of the necessary       current,
and then combine the beams using funneling                  when the beams have
acquired    sufficient     energy.
        Los Alamos officials       conducted    a preliminary     test in August
1989 on the funneling        device and plan to complete testing             within  a
year.     According  to a Los Alamos official            and other experts      we
contacted     during our review,      the concept is sound and the device
should perform as expected.           However, if technical         problems that
cannot be solved are encountered,            a tritium-producing        accelerator
would be limited     to one-half       of the power level estimated          in the
Los Alamos/Brookhaven        report.     Since such an accelerator          would be
capable of producing        only 50 percent      of the goal amount of tritium,
two accelerators     would be required        to produce 100 percent         of the
tritium    goal.4
Total   Neutron    Yield      Is Uncertain
         Brookhaven officials         have estimated        that for each proton
striking       the lead in the target        assembly,        a total    of 48 neutrons
will     be produced that can interact             with the lithium        to produce
tritium.         According     to these officials,        this is the number or yield
of neutrons        necessary     to achieve the goal amount of tritium.                Since
neutron      yield     tests have not been conducted            at the high energy (1.6
GeV) used by the tritium-producing                 accelerator,       Brookhaven's
estimate       is based primarily       on calculations         using computer codes
extrapolated         from information     obtained      from tests performed        at
lower energy.            Thus, there is some uncertainty             about neutron yield.
       Brookhaven officials              acknowledge    the uncertainty      by placing   a
20 percent    accuracy   factor            on their  calculations.       If the
calculation    is 20 percent             low, then it will       be necessary   to

4Downsized     accelerators        are     discussed    in   sec.   3.

increase     the beam energy from 1.6 GeV to about 2 GeV to          provide
additional      neutrons.     While this change is possible,   it    would
increase     both capital     and operating  costs. Brookhaven      officials
plan to conduct,        sometime during the next 2 years, more       neutron
yield    tests using high energies.

                                        SECTION 3
                         FOR NEW TRITIUM PRODUCTION
         Accelerator      production     of tritium,       compared with reactor
production,        would be potentially          safer and less harmful
environmentally.           However, these safety           and environmental
advantages        could be partially        offset    by the accelerator's
electricity        requirements,      particularly       if an additional       generating
facility      is needed.       Because of the technical           uncertainties
discussed       in section     2, estimates        of the schedule and cost for the
accelerator        are imprecise:      therefore,       potential    cost and schedule
advantages        of accelerator      production      depend on the results        of
engineering        development.
        As noted in section         2, a tritium-producing          accelerator      would
employ a multiplier          process to generate         neutrons    rather     than employ
nuclear    fission,     the process used in current             and proposed new
defense production         reactors.     Although      the precise      safety     and
environmental       advantages     depend somewhat on the final             design
parameters      of a tritium-producing          accelerator,      the absence of
fission    avoids two of the principal             safety    and environmental
concerns associated         with reactors:
      --   the possibility     of a loss-of-coolant accident,              resulting     in
           heat buildup    and/or the escape of radioactive               materials
           into the environment,      and
      --   the need to dispose        of high-level      radioactive      waste
Because the absence of fission         is inherent    in the tritium-producing
accelerator   concept,    safety    and environmental    advantages     would
accrue regardless      of accelerator    size or location.
Loss-of-Coolant Accident  Would
Pose Less Danser in Accelerator
        Nuclear reactors    are designed so that fission,      the process of
splitting     atoms, occurs as a self-sustaining      chain reaction:       When
the target     fuel (uranium)    atoms are split,   neutrons   are released,
which strike      other atoms, causing them to split,       and so on.    The
reactions     produce heat as well as a host of by-products        referred    to
as fission     products,   which produce additional     heat as they undergo
radioactive      decay.

      To prevent       the    buildup   of heat     to excessive     levels,   a coolant
is circulated       through      the reactor.       At the current      and proposed new
production      reactors      at the Savannah       River Site,    the coolant    is
heavy water.        In the     new production       reactor   proposed for the Idaho
National      Engineering      Laboratory,    the     coolant  would be helium,      an
inert    gas.
        Reactors are engineered          with control     systems designed to shut
down the fission        reaction      if the coolant     supply is interrupted.
However, the shutdown is not instantaneous:                  the nuclear   fuel
briefly     continues    to fission      until    there are no free neutrons
capable of causing a fission             reaction.      Further,  after  shutdown the
reactor     continues     to produce heat from the decay of fission
products.       Although     reactors    are equipped with systems designed to
prevent excessive        heat buildup,         concerns remain about the
possibility       of a Vlmeltdown,8t in which molten radioactive             fuel would
breach the reactor          vessel and escape into the environment.
        In contrast,    in a tritium-producing         accelerator      the proton
beam could be shut down instantaneously               and less decay heat would
be produced after       shutdown.      In normal operation         of the
accelerator,      heat would be produced as the proton beam strikes                   the
lead and lithium/aluminum          target    assemblies.      Cooling would be
provided     by water circulating        through the assemblies.            In the
event that the coolant         supply is interrupted,         the accelerator        could
be shut down instantaneously           by turning     off the proton beam, and
the target     assembly would begin to cool naturally.                A Los Alamos
scientist     estimated    that if the cooling        system should fail,         natural
convection     cooling    would be sufficient       to prevent      melting    of the
target    assemblies.
Accelerator   Would Produce
Less Radioactive   Waste
        Los Alamos officials        estimate  that because of the absence of
fission     and fission     products,    the waste produced from an
accelerator       would be less radioactive,       and remain radioactive     for a
shorter     period of time, than that from a reactor.          An accelerator
would also produce a smaller            volume of radioactive  waste.     Less
waste is an advantage because it reduces the threat              of
environmental       contamination.
       DOE categorizes     different       kinds of nuclear      waste.    High-
level waste, generated         from the reprocessing        of spent nuclear        fuel
from defense production          reactors,     has concentrations       of
radioactivity      measured in hundreds to thousands             of curies1     per
gallon     or cubic foot.      Transuranic      waste, generated      primarily     from

1A curie is a measure of the intensity   of radiation, is equivalent
to 37 billion disintegrations  per second, which is approximately
the rate of decay of 1 gram of radium.
defense reprocessing        and fabrication,       is material      contaminated     by
elements with atomic numbers higher than that of uranium.                       Low-
level waste, produced by many commercial,               industrial,       and medical
processes,     has lower levels      of radioactivity.          Low-level    waste may
require    special   handling,    although    extensive     shielding      is not
usually    required.
       Nuclear production           reactors     produce all three types of waste
noted above.          High-level     nuclear     waste from a production           reactor
derives     principally       from the spent nuclear          fuel,   which contains
radioactive       fission     products     and transuranic       elements.       Some spent
fuel elements remain radioactive                 for thousands      of years and require
permanent isolation           from the public        and the environment.            Low-level
reactor     waste includes        less-radioactive       fission     products      and items
that come into contact            with radioactive       substances,       including
tools,    gloves,       and other items used by workers.
       Radioactive       waste from an accelerator               would arise primarily
from irradiation         of the lead and lithium/aluminum                  target
assemblies.       According       to Los Alamos officials,              this waste would
remain radioactive           for a much shorter         period      of time than would
high-level      waste generated           by a reactor;      for example, at the end of
1 year, the total          radioactivity       from the accelerator            waste is
estimated     to be 25 times less than that from the reactor                        waste. In
reviewing     a list     that Los Alamos officials               provided     us of the
radioisotopes        expected to be generated            in the target         assemblies,
our consultant        determined        that relatively        few of the radioisotopes
would have a half-life            exceeding      10 years.2
         The accelerator        would also probably    produce a smaller       volume
of radioactive         waste than would a comparable         reactor.    A Los Alamos
official      noted that the volume of high-level            waste generated
annually      by one Savannah River Site reactor           exceeds the
accelerator's        total     designed target  matrix    volume.     If neither    the
irradiated       lead from the accelerator       nor the spent reactor         fuel
were reprocessed,           the storage volume of waste from a reactor            would
be roughly      twice that from an accelerator.            If the reactor      fuel
were reprocessed           and the lead were not, then the ratio         would be
less than 2 to 1.
      The estimated     capital   costs for each of DOE's proposed new
production    reactors    and for an accelerator    capable of producing
goal quantities      of tritium   do not differ  significantly.    The

2The half-life        is the time     required     for   a radioisotope        to lose    one-
half of its      activity.

estimated     life-cycle        cost for the accelerator        is somewhat less
than for either          reactor.       However, the cost estimates        for both the
reactors     and the accelerator           are surrounded     by substantial
uncertainty.         Further,      direct   comparisons    are complicated       by the
fact    that the proposed heavy water reactor               and the Los
Alamos/Brookhaven           accelerator     are designed to produce goal
quantities       of tritium,       while the proposed gas-cooled         reactor    is
designed to produce only 50 percent                 of goal quantities.
        The estimated         schedules     for the reactors        and the accelerator
suggest that the accelerator               may be constructed          more quickly.      DOE
estimated        that about 11 years would be needed to construct                    and
start    operating       the heavy water reactor            and 12 years would be
needed for the modular high-temperature,                      gas-cooled   reactor.
However, we concluded             in our September 1989 report3            that a minimum
of about 12-l/2          years for the proposed heavy water reactor                  and
about 16 years for the gas-cooled                  reactor     would be required      to
realize     tritium.         Even these estimates          are uncertain,     due in part
to technical          questions     and to safety       and environmental
considerations.            Schedule estimates         for a tritium-producing
accelerator         range from 8 to 12 years.             While these estimates         could
be increased         by technical      uncertainty,        environmental     and safety
issues should have little              effect    on the accelerator        schedule.
Estimated        Capital     Costs   Do
Not Differ        Sicnificantlv
      DOE estimated    a $3.2 billion       capital     cost for the proposed
heavy   water reactor    at Savannah River and $3.6 billion             for the
modular high-temperature,        gas-cooled     reactor     at the Idaho National
Engineering   Laboratory     (both in 1988 dollars).            However, in our
September 1989 report      we found that DOE used unrealistic
assumptions    in developing     some of its      reactor    cost estimates,    and
that  the cost would probably        increase.
        The Los Alamos/Brookhaven       report    estimated   the capital   cost of
the   accelerator      at $2.3 billion    in 1988 dollars.       A more detailed
cost estimate       performed  for Los Alamos by Grumman Aerospace
Corporation       in May 1989 estimated      this cost at $2.4 billion      in 1989
dollars.       However, this estimate       does not include     buildings  and
tunnels     to accommodate the accelerator,          nor does it include    the
cooling     system   for the target    assembly.      These items are estimated
by Los Alamos officials        to cost an additional        $600 million,   for a
total    estimated     capital cost of $3.0 billion.
        We did     not assess the accuracy of the accelerator      cost
estimates.         However,  we noted that most of the accelerator
components        have been produced and demonstrated,   albeit    under

3Nuclear     Science:         Better Information     Needed for Selection          of New
Production     Reactor        (GAO/RCED-89-206,     Sept. 21, 1989).
different     operating     conditions,      thus providing     a reasonable     basis
for the estimates.          For example, the coupled cavity           linac   and the
radio frequency       power input system have been manufactured               and
operated     at accelerator       sites.     These components represent        about 60
percent    of the estimated         capital    cost for a tritium-producing
accelerator.       In addition,        the injector    system, radio frequency
quadrupoles,      and drift     tube linac have been manufactured            and
         The accelerator     cost estimate    may be affected       significantly         by
the outcome of remaining          engineering    development    work.
Uncertainties       about the power efficiency         and neutron yield         factors,
as discussed      in section     2, could result     in either    increased        costs
or an accelerator        capable of producing      less than goal quantities              of
Life-Cycle     Cost Mav Be
Less for     Accelerator
        While the estimated          capital   costs for the heavy water reactor:
modular high-temperature,             gas-cooled     reactor:     and tritium-
producing     accelerator      are    not significantly       different,       our
computations      of life-cycle         costs show the accelerator           to be
significantly      less costly        than the reactors.
        DOE estimated      life-cycle       costs for the heavy water reactor
and the modular high-temperature                gas-cooled     reactor     at $19.7
billion    and $18.6 billion          (1988 dollars),       respectively,      based on a
40-year life.         Our computations        for the accelerator          show an
estimated     life-cycle       cost of about $10.8 billion             (1989 dollars)    for
an accelerator        with an efficiency         factor    of 54 percent      and about
$12.9 billion        (1989 dollars)       for one with an efficiency           factor   of
40 percent.
        In computing   the life-cycle     cost estimate      for the accelerator,
we used the estimated       annual operating      costs of $270 million,            which
Los Alamos and Brookhaven officials           presented    in their       March 1989
report.     This estimate     assumes that the accelerator           achieves     the
stated parameters      needed to produce goal quantities             of tritium      and
that the cost of electrical          power is 32 mils (3.2 cents) per
kilowatt    hour.    A Bonneville     Power Administration       official      told us
that    32 mils per kilowatt      hour is a reasonable       estimate      for
planning    purposes because it is based on their            wholesale       power rate
projections     for years 1989 through 2010.
Accelerator    Schedule Compares
Favorably   With Prooosed
Reactor Schedules
        In our September 1989 report,      we concluded  that DOE's
estimated       schedule of 11 to 12 years to complete,      operate,  and
realize    tritium      from the proposed new production   reactors   was
understated     and probably     would increase.        We concluded        that the
heavy water reactor       would take at least       12-l/2    years     to yield
tritium    and the modular high-temperature,            gas-cooled      reactor     would
take about 16 years.        The report    pointed    out several        uncertainties
that could further      lengthen     the estimated      schedules,      such as
technical    problems,    environmental     challenges,      safety     review
processes,    and the availability       of an industrial        base     for first-of-
a-kind reactors.
       The Los Alamos/Brookhaven     report  estimated     that it would be 8
to 9 years before tritium      would be available      from an accelerator.
An estimate     prepared by Westinghouse    Hanford officials      placed the
completion    time at 12 years.     The primary   difference    in the two
estimates   is the time allotted     to develop and demonstrate        the
front-end   components of the accelerator       under a phased constructio
       The Los Alamos/Brookhaven      report    estimated     that 3 to 4 years
would be required        to develop and demonstrate       all of the accelerator
components up to and including        the first     section     of the coupled
cavity   linac.    However, for the same work, Westinghouse            officials
believe    that about 7 years are necessary.           Both Los Alamos and
Westinghouse     agree that 5 years are necessary          to complete
development     and demonstration    of the last stage, which is the
coupled cavity      linac.
        According    to Westinghouse   officials,      the development       and
demonstration       of the front-end   components of the accelerator             are
important      because these present    80 to 90 percent          of the engineering
uncertainties.         These officials  stated that the Los
Alamos/Brookhaven        schedule does not provide        sufficient     time to test
certain     components before proceeding          with development      of others in
the front      end of the accelerator.
        The Los Alamos/Brookhaven          accelerator     designed to produce the
goal    amount of tritium      would require       at least an estimated         746
megawatts     of electrical     power if all accelerator            parameters    are
achieved.      This is equivalent        to the output of some electric
generating     plants.      The electrical      requirements      could at least
partially     offset    the accelerator's       safety   and environmental
advantages over a new production             reactor,    particularly       if the
accelerator      is considered     responsible       for the construction        of new
generating     capacity.
       Electric   generating       plants    may raise environmental            and/or
safety concerns.       For example, plants              that burn fossil      fuel have
caused concerns about their            contribution         to acid precipitation      and
global    climate  change.       A nuclear       (fission)     power plant providing
the accelerator's      electricity        could raise the safety          and
environmental    concerns associated         with fission  reactors that would
be avoided by the accelerator        itself.      As a consumer of a large
amount of electricity,       the accelerator      could be viewed as
responsible   for contributing     to these concerns.
          Also,   additional      electric   generating    capacity     in a given area
can affect        the costs of electric         service  to ratepayers      served by
the utility.           Electric    utilities    are generally     allowed   rate
structures        that enable them to recover the cost of producing                and
distributing          electricity      and enable a return     on the investment.
Therefore,        additional      generating    capacity   that increases      the
utility's       total      cost of supplying     power to its customers may result
in an increase           in the customers'      rates.
          It is important        to note that an accelerator        may not be the
only cause for a utility             to increase     its generating     capacity.
Utilities       base decisions       about constructing       new electric       generating
facilities        in part on the projected         future    demand for electricity
in their       service     area.    Many factors--     such as population        growth
patterns       or economic trends --can affect           this demand.       For a given
area, demand projections             may suggest that additional           electric
generating        capacity     will  be needed at some point        in the future.
       If a tritium-producing          accelerator    is constructed      in an area
where projected       electricity      demand is already     increasing,      then the
accelerator      may not be the sole reason for increasing               generating
capacity.     In such an area, however, the accelerator                could result
in increasing      generating      capacity    more than it would have been
increased    otherwise       or increasing     it sooner.
        The Los Alamos/Brookhaven             report   was based on a full-size
tritium-producing          accelerator       at the Hanford Reservation,         with
electricity        to be purchased        from the Bonneville       Power
Administration.           Bonneville     officials     were uncertain      about the
source of power that would be used to supply such an accelerator.
However, one official            commented that the acceleratorls            electrical
requirements         might hasten the need for a thermal              (coal or nuclear)
power plant.          The official      stated that the cost of a new power
source      would probably       be incorporated       into the overall      rates,     so
the cost of electricity             would increase       for ratepayers.      However, in
contracting        for such a large amount of electric              power, the federal
government       is likely     to have to make concessions.              Such concessions
would include         not incorporating         part or all of the cost in the
ratepayers'        base.    If this occurs,         the cost of the electricity          to
the government could possibly                double,   which could nearly       double the
operating       costs of the accelerator.
       An accelerator  designed to produce              less than 100 percent   of
the   goal amount of tritium   would require              less electric power than
one designed to produce the full                   goal amount.       Thus, building
several     smaller      accelerators        in different      locations      offers
flexibility       in meeting electrical              needs and may avoid the need to
construct     an additional          generating       plant required       to power a full-
size accelerator.            Such a strategy          could also provide         greater
security     by dispersing         tritium      production     among several         locations.
In addition,        within    certain      limits     downsized accelerators            could be
subsequently        upgraded with relative              ease to produce greater            amounts
of tritium     if needed.          However, several         downsized accelerators
capable of producing            the goal amount of tritium              collectively         would
have higher capital           and operating          costs than would a single             large
accelerator      capable of producing              the goal amount of tritium.
Immediate Electrical
Needs Would Be Smaller
        The principal       factor    affecting        the production      capacity    of a
tritium-producing         accelerator        is beam power--the          quantity    of power
that the beam deposits             on the target         assembly.      (Beam power
determines      the neutron production             rate,     that is, the number of free
neutrons     that will      result    from each proton.)            In turn,      beam power
is the product         of the electric         current      (amperage) times beam energy
 (electron     volts).      Reducing amperage, voltage,               or both would lessen
the electric        power requirements          of the accelerator.
        A Los Alamos report4         states that accelerators              to produce less
than 100 percent        of the goal amount of tritium                could be designed
and constructed       with less beam power by reducing                 either    the
amperage or the voltage           delivered       to the target.         According     to the
report,     an accelerator     producing        one-fourth     of the goal amount of
tritium     would require     about 260 megawatts of electricity,                   while an
accelerator      producing    one-tenth        of tritium    goal amount would
require     about 150 megawatts.           In comparison,       DOE's proposed
Superconducting       Super Collider,          a high-energy      particle      accelerator
to be built      in Texas, will        require      about 200 to 250 megawatts.             One
of the site selection         criteria       for the Super Collider           was the
ability     of the site to provide           sufficient     electric      power.
        Constructing       a series of smaller       accelerators        in different
locations     could thus lessen the impact on local                 electric     power
systems.      However, the operating           costs of this option          could be
higher than for a full-size             accelerator,      because the small
accelerators       collectively       could have a higher overall            electrical
need.      An accelerator        capable of producing       100 percent       of tritium
goal quantities         is estimated      to require    a total     of about 746
megawatts.       Using the Los Alamos estimates,             we calculated          that 4
accelerators       capable of producing         one-fourth      goal each would
collectively       require      about 1,040 megawatts,       while 10 accelerators

4Production  of Reduced Goal Amounts                 of Tritium      Usinq    the APT
Concept, Apr. 1989.
capable of one-tenth         goal each would collectively           require   about
1,500 megawatts.        In addition,       Los Alamos estimated        the capital
cost for an accelerator          capable of producing        one-fourth     goal at
$1.7 billion,       not including     the cost of tritium        extraction
facilities.       We estimate     that the capital       cost would be $6.8
billion      for four accelerators       that collectively       would produce the
goal amount of tritium,          assuming a capital        cost of $1.7 billion     for
each.       This compares to $3.0 billion         for one large accelerator
capable of producing         the goal amount of tritium.
Downsized Accelerators   Could Be
Unsraded to Meet Tritium   Needs
        According    to the Los Alamos report,     accelerators    capable of
producing      10 and 25 percent    of goal could be upgraded to produce
larger    quantities    of tritium   by the addition    of more electrical
power to the beam. The report          noted that during the construction
phase, space along the linac would be provided             for additional
electric     power input components.       If it would become necessary     to
produce more tritium,        then the components could be added.
       In addition,      the Los Alamos officials        pointed    out that the
downsized accelerators,          capable of producing       up to 50 percent       of
goal quantities,        would eliminate       much of the engineering      work
required     on the front     end of a full-size       accelerator.      The smaller
accelerators       would require     one-half    of the current     in the initial
stage.      Also, in this case, only one beam would be necessary,                  thus
eliminating      the funneling     of two beams into one.


APPENDIX I                                                  APPENDIX I


Robert E. Allen,    Jr.,  Assistant     Director
W. David Brooks,    Evaluator-in-Charge
Julianne   H. Hartman,   Evaluator


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