Free Response to Motion - District Court of Federal Claims - federal

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Case 1:98-cv-00126-JFM

Document 789-7

Filed 04/16/2004

Page 1 of 13

Background
" n"

The law and the regulations
The Nuclear Waste Policy Act of 1982
(NWPA) directed DOE to develop a system
for the safe and final disposal of spent nuclear fuel and high- level radioactive

waste.

program-to pay forthat effort. The NWP requires utilities with nuclear power plants to pay a fee to fund the disposal program. The Federal Government bears the costs of disposing of defense waste.
The NWP A also assigns distinct roles to the

The NWPA set an ambitious schedule for
DOE to site two geologic repositories and

Environmental Protection Agency

(EPA)

required DOE to contract with utilities begin disposal in the first one by January
31, 1998. The DOE formally identified nine

and the Nuclear Regulatory Commission

(NRC). The EPA is required to establish
standards for protection of the general en-

potentially acceptable sites across the na-

tion and later narrowed the list to three
sites: Deaf Smith County, Texas; Hanford

vironment from releases of radioactive material from a repository. The NRC is responsible for establishing technical

Washington; and Yucca Mountain , Nevada.
In 1987 , Congress directed DOE to study only one of the sites-the one at Yucca

requirements and criteria, consistent with EPA standards, for approving or disapproving applications to construct , operate, and
eventualJy close a repository. In

Mountain- to decide whether it is suitable
for a repository. This legislation, known as
the Nuclear Waste Policy Amendments Act
of 1987

1981 and 1983, NRC issued regulations for a geologic

repository in anticipation of EPA standards.
Subsequently, the Energy Policy Act of
199212 modified the process for setting en-

established the Nuclear Waste Technical Review Board , composed
10 also

of experts appointed by the President to re-

view the DOE program.

The NWP A reaffirms the Federal
Government' s responsibility for developing repositories for the permanent disposal of spent nuclear fuel and high- level radioac-

vironmental standards for a repository at Yucca Mountain. The Act directed the National Academy of Sciences (NAS) to provide findings and recommendations on
these standards and directed EPA to issue

tive waste. It also affirms the responsibility of the generators of
the waste-the nuclear

utilities and the federal defense nuclear

standards for the Yucca Mountain s based on and consistent with the NAS findings and recommendations. The Act directed NRC to revise its regulations as necessary to be consistent with the EPA
standards, once issued. The NAS published
its report in 1995.

13 The EPA is currently

developing its standards.

0056

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Case 1:98-cv-00126-JFM

Document 789-7

Filed 04/16/2004

Page 2 of 13

Background

How geologic disposal would work
The bagic concept of geologic disposal is to

place cal'efully prepared and packaged waste in excavated tunnels in geologic formatiom~ such as salt, hard rock, or clay. The concept relies on a series of barriers, natural and engineered, to contain the waste for

they differ in the barriers they emphasize. The German disposal concept , for example,
relies heavily on the geologic
bar!ier, the

rock salt formation at the prospective dis-

posal site. The Swedish method, on the
other hand, relies heavily on thick copper

thousands of years and to minimize the
amount of radioactive material that may eventually be transported from a repository
and reach the human environment.

waste packages to contain waste.
The U. S. approach , as recommended in the 1979 Report to the President by the Inter-

Water is the primary means by which radionuclides could reach the human environ-

agency Review Group on Nuclear Waste Management, 14 is to design a repository in which the natural and engineered barriers
work as a system, so that some barriers will continue to work even if others fail , and so that none of the barriers is likely to fail for

ment. rrherefore, the primary functions of the barriers are to keep water away from
the waste as long as possible , to limit the

amount of water that finally does contact the waste , to slow the release of radionuelides from the waste, and to reduce the con-

the same reason or at the same time. This design strategy is called defense in depth. The barriers include the chemical and
physical forms of the waste, the waste pack-

centrations of radionuelides in groundwa-

ter.
All countries pursuing geologic disposal are taking the multibarrier approach , though
1ft,1
, ig:!;:~","

ages and other engineered barriers, and the
natural characteristics of Yucca Mountain.

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CUtaway showing artist' s concept of the complex of underground tunnels into which waste would be emplaced. A repository at Yucca Mountain

would rely on the semiarid climate. natural barriers, and engineered barriers to contain and isolate waste for thousands of years.

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Case 1:98-cv-00126-JFM

Document 789-7

Filed 04/16/2004

Page 3 of 13

Background
.. '-'-0'_"_,,_---__-mo_....

Why Yucca Mountain? .
Yucca Mountain is remote from PQPulation
centers. L()(:ated about 100 miles northwest
years. Based upon what

is known about

the site, disruption of a repository at Yucca

of Las Vegas, Nevada, Yucca Mountain is
on the edge of the nation s nuclear weap-

Mountain by volcanoes, earthquakes, erosion , or other geologic processes and events appears ' to be highly unlikely.
Yucca Mountain has a desert climate. This

ons test. site, where more than 900 nuclear

tests have been conduct-ed.
Government.

This

unpopulated land is owned by the Federal
Yucca Mountain provides a stable geologic

is important because water movement is the primary means by which radioactive waste
could be transported from a repository.

environment. A flat- topped ridge running six miles from north to south, Yucca Mountain has changed Jittle over the last million

average, Yucca Mountain currently

receives

about seven inches of rain and snow per
year. Nearly all the precipitation, about 95
percent, either runs off or (!vaporates. Geological information indicates that the reo

gional climate has changed over the past

Location of the proposed monitored geologic repository at Yucca Mountain. Nevada

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Background
n.__- -..

million y(!ars and the long- term average precipitation has been about 12 inches per year~omparable to that of present- day
Santa Fe, New Mexico. Even if this were to

groundwater in the region is trapped within a closed desert basin and does not flow into
any rivers that reach the ocean.

be the case in the future, most of the water
would run off or evaporate rather than soak

The concept of disposing of waste in the unsaturated zone in the desert regions of the

into the ground and possibly
pository.

reach the reo

Southwest was first advanced by the U.
Geological Survey in the 1970s. In 1976,
the director of the Geological

Survey sug-

A repository would be built about 1, 000 feet
below the surface and 1

gested that the region in and around the
Nevada nuclear weapon$ test site offered a
variety of geologic formations and other attractive features , including remoteness and an arid climate. I,; In 1981 , a Geological Sur-

000 feet above the

water table in what is called the unsaturated zone. The water table is about 2 000 feet beneath the crest of Yucca Mountain.

Any precipitation that does not run off or
evaporate at the surface would have to seep down nearly 1 000 feet before reaching the repository. Between the repository and the water table, it would have to move through
. another 1 000 feet of the unsaturated zone

vey scientist noted that the desert Southwest has water tables that are among the
deepest in the world and that the region contains multiple natural barriers that

could isolate wastes for " tens of thousands

to perhaps hundreds of thousands of
years. "16

beforE! reaching

the water table. The

View of Yucca Mountain from the south

0059

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-.. - ..-.
Page 5 of 13

Case 1:98-cv-00126-JFM
Reference Design

Document 789-7

Filed 04/16/2004

_n - ..m..

_un.._. -.

The design process
Designing a repository is an iterative process. The process begins with defining the
materials that are chosen to be

compatible

with the underground thermal and
geochemical environment., and the layout

primary design objectives: protecting the . health and safety of both the workers and
the public during the period of repository

of tunnels takes into consideration the geology of the mountain.

operations; minimizing the amount of radioactive material that may eventually
reach the ar.cessible environment; and keeping costs down to an acceptable level.
To achieve the design objectives, engineers

Through successive evaluations and im-

provements, the repository design has
evolved to the current reference design. The

reference design represents a snapshot of the ongoing design process , thus providing

work with scientists to design the manmade components of a repository to work effectively with the natural system. The

a frame of reference to describe how a repository at Yucca Mountain could work. The repository design also offers insights
about how to reduce uncertainty and modify the design to improve its performance. Improvements are expected to continue as more work is completed and more information about the site is obtained.

engineered barriers are intended to work
geology and c1imate of Yucca Mountain-to contain and
with the natural barriers-the

isolate waste for thousands of years. The
waste package design , for example, includes

A conceptual model of the design process. Design objectives for repository
components are identified, and then the designs are developed, evaluated,
and improved.

0060

P A- 196048

Case 1:98-cv-00126-JFM

Document 789-7

Filed 04/16/2004

Page 6 of 13
Reference Design

The reference design
In the current reference design, spent
. At the north

entrance to the underground

nuclear fuel and high- level radioactive
waste would be transported to Yucca Moun-

repository would be the facilities and
equipment to transfer waste from shipping containers to waste packages. Each
waste package would be welded closed and thoroughly checked before being
loaded onto a shielded transporter to be

tain by truck or rail in specially designed
shielded shipping containers licensed by the Nuclear Regulatory Commission; removed from the shipping containers and placed in long- lived waste packages for disposal; carried into the underground repository by rail cars; placed on supports in the tunnels; and

taken underground.
. At the south entrance would be the

fa-

monitored until the repository is finally
closed and sealed.

cilities to support the excavation and construction of the tunnels.
. Near the

Surface facilities and operations
Surface facilities would be designed to receive the waste and prepare it for final disposal, and to support the excavation, con-

top of the mountain would be

the facilities that house the air intake and

exhaust fans for ventilating the repository.

struction, loading, and ventilation of the repository tunnels. The entire surface layout would cover about 100 acres and have three main areas:

Workers would be shielded from direct exposure to radiation and contamination be, cause waste would be handled remotely.

Artist's ooncept of repository surface facirlties

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, ...

Case 1:98-cv-00126-JFM
Reference Design

Document 789-7

Filed 04/16/2004

Page 7 of 13

Underground facilities and operations
The underground repository would consist

of about 100 miles of tunnels. The main
tunnels would be designed for moving workers, equipment, and waste packages. Ven-

would lift the waste package, carry it along the drift , and lower it onto its supports.

Current schedules anticipate that waste
emplacement would begin in 2010 if a license is received from the Nuclear Regulatory Commission, after construction of surface facilities, the main tunnels , ventilation system, and initial emplacement drifts. Additional drifts would be constructed over a period of about 20 years while waste is be-

tilation tunnels would Pl' ovide air for workers. The

emplacement tunnels (or drifts) would accommodate the waste packages, Two gently sloping access ramps and two
vertical ventilation shafts would connect the
undergTound and surface areas.

ransportation underground would be by rail. A locomotive would haul the shielded transporter with its waste package underground from the waste- handling building . to the entrance of an emplacement drift. Then a remotely operated crane (or gantry)
'l'

ing emplaced. The current design would
accommodate 70, 000 metJ'ic tons of waste,

a limit imposed by the Nuclear Waste Policy

Act of 1982. However ,

the site is large

enough to accommodate additional waste, if that were authorized.

Artist' s concept of repository underground faci~ties and operations

0062

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Case 1:98-cv-00126-JFM

Document 789-7

Filed 04/16/2004

Page 8 of 13
Reference Design

The engineered barrier system

The engineered barrier system is designed
to work with the natural geologic barriers. The reference repository design features a long- lived

and incJudes the waste Fuel Assemblyform. th(' concrete tunnel floor (or invert), and the steel
and concrete sup-

waste package

port for the waste
pa~kage.

The current waste
package design would
have two layers: a structurally strong outer layer of car-

Inner -- BarrIer lid

Backfill would consist of
crushed rock or other granu-

lar material that would
placed around the waste packages

in the emplacement drifts just before the repository is closed.
The DOE also is evaluating alternative designs , some of which might reduce uncertainties regarding repository performance. (Design alternatives ar(! discussed further under Long-Term Safety, page 30.

bon steel nearly four inches thick, and a corrosion-resistant inner layer of a high-nickel alloy about three- fourths of an inch thick. These two layers would work

together to preserve the integrity of the
waste package.

The wast(! forms inside the waste package would provide additional barriers against transport of radionuclides away from the repository. Most spent nuclear fuel is encased in Zircaloy, a metal cladding that is highly resistant to corrosion. Defense highlevel radioactive waste would be solidified

Waste Emplacement Tunnel

as glass inside stainless steel canisters.
As the design process continues , DOE is evaluating several design options that

might increase the ability of the engineered
barrier system to contain waste. These include the following:
1Q

. Drip shields that could keep

water from

dripping on the waste packages
. Ceramit coating on the waste packages
that could further prevent corrosion

. BackfilJ that could protect the

waste

packages from falling rock or tunnel collapse, raise the waste packages' tempera-

ture and lower the relative humidity

0063

PA- 196051

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Case 1:98-cv-00126-JFM
Reference Design

Document 789-7

Filed 04/16/2004

Page 9 of 13

Confirmation and retrieval
Activities to confirm that a repository would

work as expected begin long before the first

rounding rock. The effects of a repository would be monitored, and the observed ef-

waste is emj)laced. In the current site characterization phase, information about Yucca Mountain and the surrounding environment is being collected and compiled to pro-

fects would be compared to the model predictions. These confirmation

activities

would help determine whether a repository

is operating as expected.
If a problem is detected prior to closing the

vide a baseline against which to compare what would happen if a repository were built and waste were emplaced.

repository, remedial action or retrieval of
the waste would be possible using remotely
operated equipment. The Nuclear Regula-

Using mathematical models based on the
collected data and analyses of the engineered components, scientists forecast the probable behavior of the engineered system

tory Commission currently requires that a repository be designed to allow the retrieval

of waste at any time up to 50 years after
waste operations begin. Retrieval of waste,

and the effects of a repository on the Yucca Mountain environment. If repository operations begin, remote sensors would moni-

tor the waste packages , tunnels, and sur-

if needed, would follow, in reverse order, the same steps taken in emplacing the waste.

Performance confirmation
f~ Cm".

231b
Optional

CIoom

CI..ore

~M1ngol Site Sa Clllric:tfriulion Rtcommendallon
Dtdslon

l'1I

2010
Empla_nI begins

E~compItte4 Cloam
begins

The performance confirmation program begins with site characterization to establish a basefine and continues until repository dosure begins,

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Case 1:98-cv-00126-JFM

Document 789-7

Filed 04/16/2004

Page 10 of 13
Reference Design

Repository

closing
and prevent water from entering through
these openings.

Even under the most ambitious schedules
for disposal, future generations would make

the final decision to close a repository. To give future generations the option of closing the repository or monitoring it for long
periods of time, DOE is designing the repository so that it could (with Nuclear Regu-

At the surface, all radiological areas would
be decontaminated. all structures removed and all wastes and debris disposed of at approved sites. The surface area would be

latory Commission approval) be either
closed as early as 10 years after emplacement of the last waste package , or kept open for hundreds of years from the start of waste

restored as closely as possible to its origi-

nal condition. Permanent

monuments

would be erected around the site to warn

emplacement.

any future generations of the presence and nature of the buried wastes.
The DOE also would continue to oversee the

Permanently closing the repository would require the sealing of all shafts , ramps , exploratory boreholes, and other underground openings. These actions would discourage

Yucca Mountain site to prevent any activity that could

breach a repository s

engi-

any human intrusion into the repository

neered or geologic barriers, or otherwise increase the exposure of the public to radiation beyond allowable limits.

1t~

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0065

P A- 196053

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Case 1:98-cv-00126-JFM
Performance Assessment

Document 789-7

Filed 04/16/2004

Page 11 of 13

Performance assessment models
Performance assessment evaluates how a
repository system is likely to work over long . time periods. From the results of scientific

system are most important to how well it is

likely to work , and where scientists and en-

studies , analysts build detailed mathematical models or "representations" of the features , events , and processes that could af. feet the performance of the design. They then incorporate the results of these detailed process models into an overall model
of the J'!pository system , which is called the

gineers might most usefully focus their . efforts to improve performance. These assessments are repeated and refined during the course of developing, evaluating, and improving a repository design.
A total system performancE! assessment rep-

total system performance assessment
model. The models are used to assess how
the natural and engineered elements of a

resents a reasonable approach to the challenging task of projecting how a repository would work over thousands of years. How.

ever , as a National Academy of Sciences
panel observed, "Confidenc:e in the disposal techniques must come from a combination

waste disposal system are likely to work
together over the long period required to

isolate wastes.

of remoteness, engineering design, math-

Performance assessments help identify
which uncertainties about the behavior of a disposal system are significant and which
are not ,

which elements of the repository

unforeseen events."17 The DOE is taking this combined approach.

ematical modeling, performance assessment, natural analogues and the possibility of remedial action in the event. of

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Approach to constructing a total system performance assessment (TSPA) model, Analysts develop detailed mathematical models of the natural processes that are important to repository
performance and then combine these models Into a model of the entire repository system,

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Case 1:98-cv-00126-JFM

Document 789-7

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Page 12 of 13
Performance Assessment

The attributes of safe disposal
The results of fifteen years of testing and

analysiE;, including four years of underground exploration , have validated many,

The results indicate that a repository at Yucca Mountain would need to exhibit four key attributes to protect public health and

but not all, of the expectations of scientists who first suggested that remote desert rcgions are well-suited for a geologic reposi-

the environment for thousands of years.
The four key attributes nre:
. Limited water contact with waste pack-

tory. One important and Uliexpected test
result was finding underground, at the level

ages
. Long waste package

of the proposed repository, traces of a radioactive isotope (chlorine- 36)
that is asso-

lifetime

ciated with above- ground nuclear weapons tests. As atmospheric nuclear testing began in the mid- 1940s , this finding suggests that. some water travels from the ground

. Low rate of release ofmdionuclides breached waste packages
. Reduction in the

from

repository in about 50 years or less. Another important finding was evidence that the average amount
surfacE! to the level of the

concentration of radio.

. nuclides as they are transported from
breached waste packages

of water that filters down through the
mountain is about a third of an inch per
year, which , while only about five percent of the average annual precipitation, is more than DOE initially expected. Taken together, the findings, both expected and un-

Based on performance assessment models

DOE has evaluated the degree to which the

reference design exhibits these four key at-

tributes, and has identified additional scientific studies and design improvements
that could reduce uncertainties and enhance
long- term
repository performance.

expected. underscore the importance of
building engineered barriers that work with

the natural barriers to keep water away
from the waste.

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Case 1:98-cv-00126-JFM
Performance Assessment

Document 789-7

Filed 04/16/2004

Page 13 of 13

_u o--u',. '

Limited water contact with waste packages
In the reference design ,

waste packages

Once waste packages have been placed in
the repository, the heat g(merated from ra-

would be placed about 1 000 feet below the mountain s surface and about 1 000 feet

above the water table. Even if future climates are much wetter than today, the
mountain is not expected to erode and leave

decay would raise the temperature in the tunnels above the boiling point of water. The heat is eXl)ected to dry out
dioactive

th~ surrounding rock and drive any water

the waste.

the waste exposed, and the water table is not expected to rise high enough to reach

away for hundreds to thousands of years.
However, as the waste decays and the repository cools, enough water to cause drips

would begin to seep into the drifts through
fractures in the roc

In the current semiarid climate , about seven

inches of water a year from rain and snow fan on Yucca Mountain. Nearly an of that precipitation , about 95 percent, runs off or evaporates. Only about one- third of an inch
of water per year moves down (or percolates)

Using mathematical models , analysts esti. mate that, after the repository cools enough,

about five percent of the packages could experience dripping water, under the current

through the nearly 1, 000 feet of rock to
reach the level of the repository. Studies of past climates indicate that the precipitation may increase to a long- term average of
about 12 inches per year. However, most of the water stiU would run off or evaporate
rather than soak into the ground.

climate. If the climate changes to a wetter
long- term
average ,

about 30 percent of the

packages could experience dripping water. These estimates are based on a number of
assumptions that remain to be validated. Nonetheless , the results suggest that lim-

ited water would contact the waste packages.
Ongoing testing in the exploratory tunnels is providing more information on how much
water could enter the repository and con-

tact the waste packages under a variety of conditions. The DOE is also evaluating alternative waste package designs and other options that would mitigate the effects of
water contact and improve performance of a repository.

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P A- 196056