Number range CHAPTER**ENVIRONMENTAL RADIATION PROTECTION STANDARDS**

**FOR YUCCA MOUNTAIN, NEVADA**

CAPT Raymond L. Clark, U.S. Public Health Service

Team Leader for the Yucca Mountain Standards

Office of Radiation and Indoor Air (6608J)

U.S. Environmental Protection Agency

Washington, D.C. 20460-0001

202-564-9300

**ABSTRACT**

The Environmental Protection Agency (EPA) has issued radiation
protection standards for the potential spent nuclear fuel and high-level
radioactive waste disposal system in Yucca Mountain, Nevada. These
standards are found in Part 197 of Title 40 of the Code of Federal
Regulations (40 CFR Part 197). The Energy Policy Act of 1992 directed,
and gave the authority to, EPA to take this action based upon input from
the National Academy of Sciences (NAS). The final standards were
published in the *Federal Register* (66 FR 32073) on 13 June 2001.

The 40 CFR Part 197 standards have four major parts: (1)
individual-protection during storage activities; (2)
individual-protection following closure of the repository; (3)
human-intrusion; and (4) ground-water protection. The storage standard
is 150 microsieverts (Sv) annual committed effective dose equivalent
(CEDE) to any member of the general public. The disposal standards are:
(1) 150 Sv annual CEDE for the reasonably maximally exposed individual
(RMEI) for 10,000 years after disposal; (2) 150 Sv received by the RMEI
within 10,000 years after disposal as a result of human intrusion; and
(3) the levels of radionuclides in the ground water cannot exceed 40 Sv
from beta and gamma emitters, 5 picocuries per liter (pCi/L) of
radium-226 and -228, and 15 pCi/L of gross alpha activity. There are
also requirements related to the post-10,000-year period, the basis of
compliance judgments, and performance assessments.

The Agency has published its responses to the comments received, its
technical background document, and its economic impact analysis. In
addition to printed form, the documents are available on the World Wide
Web at http://www.epa.gov/radiation/yucca/index.html.

**INTRODUCTION**

The U.S. Environmental Protection Agency (EPA) issued radiation
protection standards for the potential spent nuclear fuel and high-level
radioactive waste disposal system in Yucca Mountain, Nevada on 13 June
2001 (1). (The term \"repository\" is used in this paper to refer to the
mined facility, while the term \"disposal system\" is used to refer to
the entirety of the mined facility, the engineered barriers, and the
geologic barrier.) The Energy Policy Act of 1992 (EnPA) directed EPA
\"to set generally applicable standards for the Yucca Mountain
site\...for protection of the public from releases from radioactive
materials stored or disposed of in the repository at the Yucca Mountain
site\" (2). It also directed EPA to set the standards "based upon and
consistent with" the results of a contract with the National Academy of
Sciences (NAS) to \"conduct a study to provide \[to EPA\]\...findings
and recommendations on reasonable standards for protection of the public
health and safety....\" (the NAS Report, 2). The standards are in
Part 197 of Title 40 of the Code of Federal Regulations (40 CFR Part
197).

In previous papers, EPA has reported upon the findings and
recommendations in the NAS Report, public comments received from the
review of the NAS Report, and the range of the EPA's considerations
while establishing standards based upon the NAS Report's findings and
recommendations. This paper reviews the provisions of the final
standards.

**STORAGE STANDARD**

Subpart A of 40 CFR Part 197 contains the storage standard. It limits
the doses, received by members of the public, coming from management and
storage which occurs prior to closure of the repository. The standard is
150 microsieverts (Sv) annual committed effective dose equivalent
(CEDE). "Annual committed effective dose equivalent" is the CEDE
resulting from one year's intake of radionuclides plus the annual dose
received from external radionuclides released from the storage area. It
applies to any member of the public in the general environment. The
general environment is anywhere outside the Yucca Mountain site, the
Nellis Air Force Range, and the Nevada Test Site. Storage was not
addressed by NAS.

The standard covers management and storage occurring within the
repository combined with the activities on the surface and defines the
interaction between 40 CFR Part 197 and Subpart A of 40 CFR Part 191,
*Environmental Radiation Protection Standards for Spent Nuclear Fuel,
High-Level and Transuranic Radioactive Wastes* (3). The interaction
between 40 CFR Parts 191 and 197 is necessary because 40 CFR Part 191 is
based upon the older critical-organ dose system, whereas 40 CFR Part 197
is based upon effective dose equivalent. The Agency considered setting
an overall dose limit using only annual CEDE, but decided that the
bifurcation is necessary (largely because the EnPA specifies that the
standards cover storage [in]{.underline} the repository) despite the
fact that it is advantageous to have a single methodology.

**DISPOSAL STANDARDS**

Subpart B of 40 CFR Part 197 contains the disposal standards for: (1)
protection of individuals; (2) human intrusion; and (3) ground-water
protection. The disposal phase is considered to start when the
repository is closed. Disposal was the subject of the findings and
recommendations of the NAS Report (4).

**Role of the NAS Report**

The question was raised following the release of the NAS Report as to
whether EPA believed itself to be bound to the NAS' findings and
recommendations. Many of the NAS' findings and recommendations are
written in a non-binding manner because NAS recognized that many of the
issues are not scientific or technical but rather societal policy issues
to be determined through an EPA public rulemaking process. Therefore, it
is clear that these are non-binding. But what about those findings and
recommendations which are stated in relatively definite terms?

The EPA does not believe that Congress intended for public rulemaking to
be bypassed since the EnPA stipulated that the standards be "promulgated
by rule." Also, the Conference Report accompanying the EnPA stated, "The
provisions of section 801 \[of the EnPA\] are not intended to limit the
Administrator's \[of EPA\] discretion in the exercise of his authority
related to public health and safety issues" (5). In summary, EPA does
not believe that it is bound to adopt the NAS' findings and
recommendations. However, the NAS' findings and recommendations played a
dominant role in the Agency's deliberations.

**Reasonable Expectation**

All of 40 CFR Part 197\'s disposal standards are based upon the concept
of "reasonable expectation." Reasonable expectation means that the
Nuclear Regulatory Commission (NRC) is satisfied that compliance will be
achieved based upon the full record before it. Reasonable expectation is
used by EPA to recognize that absolute proof is neither necessary nor
possible to obtain since performance of the disposal system must be
projected for at least 10,000 years. "Reasonable expectation" is
distinct from the concept of "reasonable assurance" as it has developed
over the years in nuclear power reactor licensing. The difference
between projecting the performance of an engineered system with a
cumulative experience of hundreds of years of operation versus
projection of the performance of a new type of combined engineered and
natural system with no operational experience to date is clear. The EPA
is trying to recognize that the uncertainty involved in projecting the
performance of the disposal system is much greater than for a reactor.
Further, "reasonable expectation" is intended to be cautiously realistic
in that it does not exclude important parameters simply because they
cannot be quantified to a high degree of confidence, whether they
contribute to, or detract from, disposal system performance. That is not
to say that parameter values can be arbitrary, but rather, that ignoring
effects of parameters (the values of which are reasonable based upon
research or expert judgment) or using only their extreme values can lead
to assessments of performance which have a high probability of being
unrealistic or have such a low probability of occurring that they would
not be representative of the range of likely performance.

**Individual-protection Standard**

[Form.]{.underline} There was disagreement between the EnPA and the NAS
recommendation as to whether this standard should be stated in terms of
risk or dose. The NAS recommended risk, whereas the EnPA stated that the
standard was to be a dose limit. The EPA decided to use dose. First,
advisory bodies such as the International Council on Radiation
Protection and the National Council on Radiation Protection have
recommended that standards be stated in dose. Second, most existing
national and international radiation standards are stated in dose.
Third, dose and risk are closely related mathematically. In addition,
the dose standard is based upon the lifetime risk of an individual
developing a fatal cancer (using the linear, non-threshold,
dose-response relationship). Therefore, risk is the basis for the limit
anyway. Fourth, the EnPA called for a dose limit. And, finally, most
commenters on the NAS Report favored dose.

[Level.]{.underline} The individual-protection standard is 150 Sv
annual CEDE. The NAS recognized that the appropriate level is a question
of both science and public policy. There were several bases for the
proposed level. First, it is within the range that the NAS recommended.
The NAS stated that a starting point for the rulemaking should be within
an annual risk of 10^-6^ to 10^-5^ \-- about 20 to 200 Sv per year.
Second, it represents a 50-year lifetime risk of about 4 x 10^-4^. This
is about the upper value of the range of the risk that EPA generally
uses to judge the acceptability of non-radiation-related activities. The
EPA generally considers a range of about 10^-6^ to 10^-4^ lifetime risk
as an acceptable risk range for regulation. And, finally, it is
consistent with the individual-dose limit in 40 CFR Part 191 that is the
basis for the certification of the Waste Isolation Pilot Plant (WIPP)
and the decision on the Greater Confinement Disposal system.

[The representative of the exposed population.]{.underline} The NAS
recommended that EPA use the average risk within a critical group to
determine compliance with the individual-protection standard. They cited
two examples of critical groups that might be used. One was a group of
subsistence farmers, while the other was a statistical/probabilistic
representation of the doses received by the population in the region
surrounding Yucca Mountain (4).

The Agency chose to use a reasonably maximally exposed individual
(RMEI). The concept is similar to the critical group concept in that its
purpose is to project doses that are within a reasonably expected range
rather than the highest theoretical dose. This is accomplished by using
cautious, but reasonable, parameter values and is to be based upon what
EPA believes is a common lifestyle in Amargosa Valley, Nevada. Ground
water is to be assumed to be consumed at a rate of two liters per day
per person and a portion of the diet is to be from locally grown food
that was grown using the ground water.

[Location.]{.underline} The location of the RMEI must be assumed to be
in the accessible environment above the point of highest concentration
of radionuclides in the aquifer. The accessible environment can be no
farther downgradient than the southern edge of the Nevada Test Site
(NTS), or about 18 kilometers south of the repository (see the Point of
Compliance discussion in the Ground-water Protection Standards section
below for more details). Overall, it appears that an individual could
reside anywhere downgradient from about five kilometers to 30 or more
kilometers from the repository. However, the ability of an individual to
reside at any particular point is dependent upon that person's purpose
and resources since the ground water is deeper near the proposed
repository (about 300 meters in depth) and decreases in depth with
distance from the repository until there are surface discharges 30 to 40
kilometers away. The EPA believes that the rougher terrain and expense
of recovering water significantly north of Lathrop Wells would
discourage settlement by individuals, particularly since water is more
easily accessed just a few kilometers farther south. Similarly, EPA
found that commercial agriculture is unlikely north of Lathrop Wells
because of the cost of water recovery, but that it would be reasonable
to assume that an RMEI could live near Lathrop Wells and recover some
water for domestic purposes. The EPA also believes that an individual
living in this location would be among the most highly exposed
individuals even though water closer to the repository would likely
contain higher concentrations of radionuclides. This is counterintuitive
until you remember that EPA believes that individuals would not live
closer because of the cost and physical/technical difficulty of
recovering that water.

**Ground-water Protection Standards**

[Level of protection.]{.underline} Water which flows under Yucca
Mountain is being used for drinking water by members of the public
starting as close as 20 kilometers south of the proposed repository.
Since ground water is particularly valuable in this desert setting and
is the sole source of water south of Yucca Mountain, EPA believes that
it should be separately protected. The overall goal is to prevent
adverse effects upon human health and the environment by preventing
contamination rather than relying upon later mitigation. The level of
protection is provided in Table I. This approach provides the same
protection regarding Yucca Mountain that exists elsewhere in the country
for other waste disposal projects. The time frame for these standards is
10,000 years of undisturbed performance, i.e., the repository is not
affected by human intrusion or unlikely features, events, or processes
(FEPs).

Table I. Limits on Radionuclides in the Representative Volume

  ----------------------------- ----------------------- ------------------
  Radionuclide or type of       Limit                   Is natural
  radiation emitted                                     background
                                                        included?

  Combined radium-226 and       5 picocuries per liter  Yes
  radium-228                                            

  Gross alpha activity          15 picocuries per liter Yes
  (including radium-226 but                             
  excluding radon and uranium)                          

  Combined beta and photon      40 microsieverts (4     No
  emitting radionuclides        millirem) per year to   
                                the whole body or any   
                                organ                   
  ----------------------------- ----------------------- ------------------

[Representative volume.]{.underline} The EPA also proposed the concept
of a representative volume of ground water. This is the volume of ground
water in which the concentrations of radionuclides will be calculated.
The intent is to provide a basis that is conservative, but reasonably
implementable. In other words, EPA believed that it is unreasonable to
require projections of concentrations in small volumes, for example, a
few gallons of water in a fracture. On the other extreme, it is neither
reasonable nor conservative to assume that all of the water in an entire
hydrologic sub-basin would be involved.

The EPA considered four different volumes (the metric volumes listed are
approximate) before choosing 3,714,000,000 liters (3,000 acre-feet). The
smallest volume was 12,380,000 liters (10 acre-feet). This is the
estimated annual volume of water used by a community of 25 people for
domestic purposes or a non-farming family of four with a garden. It is
also the lower bound for the amount of water which would be used in a
public water supply (which is defined as a system serving at least 25
people). The next largest volume considered was 148,560,000 liters (120
acre-feet). The basis of this volume is a community of 150 people. This
population was intended to reflect the estimated population increase
over the next 20 years around Lathrop Wells. It was also assumed that
this community would likely use water for more than just domestic
purposes, such as light industrial or tourist use. The third volume
considered was 1,591,023,000 liters (1,285 acre-feet). This volume is
based upon the average size of an alfalfa farm in Amargosa Valley,
Nevada, i.e., about 103 hectares (255 acres). The estimated annual
irrigation rate is about 6,190,000 liters (5 acre-feet) per acre.
Multiplying the two values yields 1,578,450,000 liters (1,275 acre-feet)
per year. An extra 12,380,000 liters (10 acre-feet) per year is added
for domestic use of 25 people in the community. And, finally, the Agency
considered 4,952,000,000 liters (4,000 acre-feet) per year. This is
representative of the estimated perennial yield of the Jackass Flats
hydrologic sub-basin, i.e., the amount of water that could be removed
from the sub-basin without significantly decreasing the yield and
quality of water in the future.

The Agency chose 3,714,000,000 liters (3,000 acre-feet) per year because
it was deemed to be a cautious, but reasonable, value which represents
the current and currently projected types of water use at Lathrop
Wells/Amargosa Valley. It is based upon the estimated annual volume of
water used by two average-size (for southern Amargosa Valley) alfalfa
farms (3,160,000,000 liters or 2,550 acre feet per year), the planned
commercial/industrial use near Lathrop Wells (124,000,000 liters or 100
acre-feet per year), and individual/municipal water use for a small
community consistent with the near-future growth projections in the area
(149,000,000 liters or 120 acre-feet per year). This sums to an annual
use of 3,430,000,000 liters (2,770 acre-feet). To account for
uncertainty in these projections, another 285,000,000 liters (230
acre-feet) per year were added to arrive at 3,714,000,000 liters (3,000
acre-feet).

To calculate the concentrations of radionuclides in the representative
volume, EPA proposed two approaches, either of which may be used for
compliance determination. The first approach is termed the "well-capture
zone." In this approach, the dimensions of the representative volume are
based upon a well that is pumping an annual volume equal to the
representative volume. The dimensions of the well-capture zone are
determined by the pumping rate in combination with aquifer
characteristics such as hydraulic conductivity and gradient, and the
length of the screened interval of the well. The Department of Energy
(DOE) must assume that the well has characteristics consistent with
public water supply wells in Amargosa Valley and that the screened
interval of the well is centered in the highest concentration in the
contamination plume. The second approach is termed the "slice of the
plume." This approach is based upon a cross-section of the plume of
contamination with sufficient thickness parallel to the prevalent flow
of the plume of contamination that it contains the representative
volume. The DOE and NRC must determine where the edge of the plume of
contamination is, for example, where the concentration falls to 0.1% of
the highest concentration. Finally, the "slice" must be perpendicular to
the prevalent flow of the aquifer.

[Point of compliance.]{.underline} The EPA proposed four potential
points of compliance. They ranged in a downgradient limit on distance
from five kilometers to about 30 kilometers from the repository. There
were two concepts for the points of compliance. First was the controlled
area. This concept is used in 40 CFR Part 191. A controlled area is an
area, and its underlying geology, in which the ground water standards
would not apply. This means that the standards must be met anywhere
outside of the area. Compliance is generally determined at the boundary
of the controlled area. The second approach is to name a specific point
based upon the understanding of the ground water flow and economic and
land use factors in the area. This approach necessitates a contingency
provision in case the ground water flow or other factors are found not
to meet the underlying understanding, with the result that the highest
concentration is found somewhere besides the specified point.

The first alternative was a controlled area. It would be defined the
same as in 40 CFR Part 191, i.e., the boundary of the area could be no
farther than five kilometers from the waste and the area could not
exceed 100 square kilometers. This is the same requirement under which
the WIPP disposal system was certified.

The second alternative was a point location. That point would be at
Lathrop Wells (about 20 kilometers from the waste). The depth to ground
water in this location is about 110 meters.

The third alternative was, again, a point that would be determined by
DOE and NRC within a specified area about 30 kilometers south of the
emplaced waste. This area encompasses a large part of the agricultural
area in southern Amargosa Valley. The depth to ground water in this area
is roughly 20 to 40 meters.

In case the ground water does not flow in the direction which is now
thought, for the second and third alternatives, a new point of
compliance must be established at the same distance from the emplaced
waste as the original point but centered over the highest concentration
of radionuclides in the aquifer.

The fourth and final alternative was a controlled area. This could be
considered a combination of two controlled areas. The first would be
limited to a distance of five kilometers from the emplaced waste. The
second would be the current boundary of the Nevada Test Site. Where
these two areas overlap, the Nevada Test Site boundary would be the
boundary to be used. If the ground water flows southward from the waste
(as currently thought) and DOE and NRC used the southern boundary of the
Nevada Test Site as the southern limit of the controlled area, the
downgradient edge of the controlled area would be about 18 kilometers
from the emplaced waste.

The Agency decided to use a controlled area that is similar to the
fourth alternative. The controlled area must: (1) be identified by
passive institutional controls; (2) encompass no more than 300 square
kilometers and (2) extend no farther south than 36 40\' 22.391\" north
latitude (the southernmost edge of the Nevada Test Site), in the
predominant direction of ground water flow. The compliance point is then
the point in the accessible environment (anywhere outside of the
controlled area) where the highest radionuclide concentration is
projected to occur during the compliance period (10,000 years).

As mentioned above, the size of the controlled area may not exceed 300
km^2^. That limit was derived by combining the concept of the controlled
area as used in 40 CFR Part 191 and the requirement for a site-specific
standard for Yucca Mountain. If fully employed by DOE, and based upon
current repository design, the controlled area could extend
approximately 18 km in the direction of ground water flow (presently
believed to be in a southerly direction) and extend no more than five km
from the repository footprint in any other direction. Allowing for a
nominal repository footprint of a few square kilometers, this results in
a rectangle with approximate dimensions of 12 km in an east-west
direction and 25 km in a north-south direction, or approximately 300
km^2^. The DOE may define the size and shape of the controlled area, but
the boundaries cannot extend farther south than latitude 36^^ 40\'
22.391\"North in the direction of ground water flow and five km in any
other direction.

**Human-intrusion Standard**

There were two alternatives proposed for the human-intrusion standard.
They both limit the annual CEDE to 150 Sv. However, the first
alternative limits the consideration to the first 10,000 years after
disposal. The second alternative recognized that an intrusion might not
be able to occur prior to 10,000 years. Therefore, in addition to the
dose limit for the first 10,000 years, there is a requirement that the
results of the analysis and its bases be placed in the Yucca Mountain
environmental impact statement as an indicator of long-term performance
following the intrusion.

The Agency decided to establish two different ways for DOE to proceed
depending upon the projected time of the intrusion. If waste package
penetration is projected to occur 10,000 years or sooner after disposal,
DOE must demonstrate that there is a reasonable expectation that the
dose limit will be met and, if exposures of the RMEI will occur beyond
10,000 years after disposal, the results of the analyses and their bases
must be placed into the Yucca Mountain environmental impact statement.
However, if the intrusion is projected to occur after 10,000 years,
there is no quantitative dose limit, but the results of the analyses and
their bases must be placed into the Yucca Mountain environmental impact
statement.

One of the issues that Congress asked NAS to address was whether active
institutional controls could effectively stop human intrusion into the
repository. The NAS found that it could not. The NAS recommended that
EPA assume that an intrusion will occur at Yucca Mountain (rather than
using a probabilistic approach) and establish an appropriate scenario
for DOE to analyze. They also recommended that EPA establish a standard
as a test for the resiliency of the repository and set it at the same
level as the individual-protection standard.

The human-intrusion scenario that EPA chose specifies the basic
parameters values for the diameter and other characteristics of the
borehole. The DOE is then to assess the dose received by the RMEI as a
result of only the releases which travel through the borehole, without
consideration of any unlikely FEPs ocurring. The scenario is a single
intrusion as a result of exploratory drilling for ground water. The DOE
must assume that the intruders drill a borehole directly through a
degraded waste package into the uppermost aquifer underlying the Yucca
Mountain repository using common techniques and practices that are
currently employed in exploratory drilling for ground water in the
region surrounding Yucca Mountain. Further, it cannot be assumed that
careful sealing of the borehole occurs, but rather that natural
degradation processes gradually modify the borehole. The standard also
requires that the human-intrusion analysis use the same methods and RMEI
characteristics as those required for the individual-protection
standard, with two exceptions. The first exception is that the
human-intrusion analysis would exclude unlikely FEPs. The second
exception is that the analysis would address only releases moving
through the borehole.

The timing of the intrusion is to be established by NRC based upon the
earliest time that current technology and practices could lead to waste
package penetration without the drillers noticing it. However, it must
not occur sooner than the cessation of active institutional controls.
The Agency's information about drilling and experiences of drillers
indicates that special efforts, such as changing to a specialized drill
bit, likely would be necessary to penetrate intact, non-degraded waste
packages of the type DOE plans to use. Further, EPA believes that the
time frame for the drilling intrusion should be within the period that a
small percentage of the waste packages have failed but before
significant migration of radionuclides from the engineered barrier
system has occurred because that would be about the earliest time that a
driller would not recognize an impact with a waste package.

**OTHER CONSIDERATIONS**

[Lower limit on processes and events to be considered.]{.underline} In
40 CFR Part 191, there is a lower limit on the probability of events and
processes that need to be considered in the performance assessment. That
provision is that the events and processes which have a probability of
less than 1 in 10,000 of occurring within 10,000 years after disposal
did not need to be included in the analyses. The Agency decided to apply
that same limit to the Yucca Mountain performance analyses.

[Underground injection.]{.underline} This issue was first brought to
EPA's attention in the lawsuit challenging the original (i.e., 1985) 40
CFR Part 191 (7). In remanding the disposal standards to EPA, the court
found that a geologic repository might be a form of underground
injection. The EPA later issued amendments to the disposal standards in
40 CFR Part 191 in response to the court's remand (6). In the preamble
to the amendments, EPA concluded, based upon a review of the Safe
Drinking Water Act (8), its legislative history, and the regulations
governing the underground injection control program, that disposal of
containerized radioactive waste in geologic repositories does not
constitute underground injection. The result for the Yucca Mountain
disposal system is the continuation of the previous decision, i.e., the
Agency does not believe that the disposal of containerized radioactive
waste in geologic repositories is underground injection for the purposes
of the SDWA (8).

[Assurance requirements.]{.underline} In 40 CFR Part 191, EPA included
several qualitative principles which were intended to supplement the
protection afforded by the quantitative standards because of the
inherent uncertainty in the required long-term projection of disposal
system performance. Those requirements covered the need for passive and
active institutional controls, monitoring, the use of multiple barriers,
the need to be able to locate and remove the waste after disposal, and
the need to avoid areas with natural resources, unless the advantages of
the site outweighed the potential for the increased probability of human
intrusion. These provisions were not proposed for Yucca Mountain,
however, EPA did request comments on including such requirements.

The Agency decided to not include assurance requirements in 40 CFR Part
197. This decision was based upon public comments which mostly said that
it was redundant with NRC's 10 CFR Part 63 and the provisions made for
NRC regarding 40 CFR Part 191. Those provisions are that the assurance
requirements in 40 CFR Part 191. However, they do not apply to
facilities that the NRC regulates, based upon the understanding that NRC
would include them in its licensing regulations in 10 CFR Part 60. The
NRC is the licensing agency for Yucca Mountain; therefore, at first
glance it appears that requiring assurance requirements at Yucca
Mountain would be inconsistent with our approach in 40 CFR Part 191 and,
therefore, should not even be considered. However, the EnPA mandates
that EPA set site-specific standards for Yucca Mountain, so these
provisions were once again considered. However, EPA decided that it was
unnecessary to include similar requirements in 40 CFR Part 197 since
NRC's proposed licensing criteria (see 10 CFR §§ 63.102, 63.111, and
63.113; 64 FR 8640, 8674-8677, February 22, 1999) contained requirements
similar to the assurance requirements in 40 CFR Part 191 for multiple
barriers, institutional controls, monitoring, and the retrievability of
waste from Yucca Mountain,

[Expert elicitation.]{.underline} The EPA also considered setting
guidelines for the use of expert elicitation, in concert with
performance assessments, and solicited comments upon doing so. The
provisions considered were: (1) the NRC needs to consider the source and
use of the information; (2) to the extent possible, experts with
appropriate expertise and independence from the DOE will be chosen for
the panel; and (3) DOE should present information to the panel in a
public meeting with an opportunity for other qualified experts to
present information, also. The EPA would also allow NRC to use the
results of expert elicitations which were completed prior to the
finalization of 40 CFR Part 197. The Agency decided to leave the
specification of the use of expert elicitation to NRC and DOE. The
Agency stated that it believes that NRC and DOE "are sufficiently
sensitive to public opinion\...to avoid the appearance of secrecy or
targeted polling of experts to obtain the specific outcome." (1)

**PUBLIC PARTICIPATION AND CURRENT STATUS**

The EPA published the proposed standards in the 27 August 1999 *Federal
Register* (9). A public comment period was open from then until November
26, 1999. Public hearings were held in Washington, D.C. on 13 October
1999; Amargosa Valley, Nevada on 19 October 1999; Las Vegas, Nevada on
20-21 October 1999; and Kansas City, Missouri on 27 October 1999.
Approximately 800 comments were received.

On 13 June 2001, the Agency published its final Yucca Mountain standards
(1). The Agency has also published its response-to-comments document and
the final versions of its background information document, which
provides the technical bases for the standards, and its economic impact
analysis of the standards upon the disposal system and the program
supporting it.

The Yucca Mountain standards and supporting documents may be accessed on
the EPA World Wide Web site at http://www.epa.gov/radiation/yucca. There
is also a toll-free telephone information line at 1-800-331-9477.

# REFERENCES

1\. *Environmental Radiation Protection Standards for Yucca Mountain,
Nevada: Final Rule*, *Federal Register,* Volume 66, No. 114, pp.
32073-32135, 13 June 2001.

2\. *Energy Policy Act of 1992*, Public Law 102-486, 106 Stat. 2921.

3\. *Environmental Radiation Protection Standards for the Management and
Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive
Waste*, Part 191, Title 40, Code of Federal Regulations.

4\. *Technical Bases for Yucca Mountain Standards*, National Research
Council, National Academy Press, Washington, DC, 1995.

5\. House of Representatives, Report 1018 at p. 391, 1992.

6\. *Amendments to the Environmental Radiation Protection Standards for
the Management and Disposal of Spent Nuclear Fuel, High-Level and
Transuranic Radioactive Waste*, *Federal Register,* Volume 58, No. 242,
pp. 66397-66416, December 20, 1993.

7\. NRDC v. EPA, 824.F.2d at 1270-71.

8\. *Safe Drinking Water Act*, 42, U.S. Code 300g-1.11, *Federal
Register,* Volume 64, No. 166, pp. 46976-47016, August 27, 1999.

9\. *Environmental Radiation Protection Standards for Yucca Mountain,
Nevada: Proposed Rule*, *Federal Register,* Volume 64, No. 64, pp.
46975-47016, 27 August 1999.