Copyright 1999 Federal News Service, Inc.
Federal News Service
FEBRUARY 10, 1999, WEDNESDAY
SECTION: IN THE NEWS
LENGTH:
1411 words
HEADLINE: PREPARED STATEMENT OF
DR.
JARED L. COHON
CHAIRMAN
U.S. NUCLEAR WASTE TECHNICAL REVIEW BOARD
BEFORE THE HOUSE COMMITTEE ON COMMERCE
SUBCOMMITTEE ON
ENERGY AND POWER
BODY:
Mr. Chairman, and
members of the Subcommittee, good afternoon. My name is Jared L. Cohon. My
full-time job is President of Carnegie Mellon University. I am here today in my
capacity as Chairman of the Nuclear Waste Technical Review Board. It is my
'pleasure to represent the other members of the Board at this hearing.
As
you know, Mr. Chairman, Congress created the Board in the 1987 amendments to the
Nuclear Waste Policy Act to review the technical and scientific validity of
activities undertaken by the Secretary of Energy, including the characterization
of the Yucca Mountain site and the packaging and transportation
of spent nuclear fuel and high-level radioactive waste. The Board takes very
seriously its role as the main source of ongoing technical and scientific review
of the Department of Energy's (DOE) civilian radioactive waste management
program.
The Board has been asked to comment today on the DOE's recently
issued viability assessment (VA) of the Yucca Mountain site and
on H.R. 45, legislation amending the Nuclear Waste Policy Act of 1982. I will
make Some very brief remarks, and I ask that the full text of my statement be
entered in the hearing record.
Comments on H.R. 45
Mr. Chairman, many of
the issues raised in H.R. 45 are policy matters that are outside the technical
and scientific purview of the Board. I will therefore not comment on the
specific provisions of H.R. 45, except to urge that if phased development of an
interim storage facility is authorized, sufficient resources are allocated so
that scientific testing to support decisions about the suitability and possible
licensing of the Yucca Mountain site can continue. I will be
pleased to respond at the end of my statement to specific technical questions
about the legislation from Subcommittee members.
During the last year, the
Board has devoted the majority of its efforts to (1) identifying the key areas
of research whose results would improve the technical basis for making decisions
about site recommendation and licensing, if the site is determined to be
suitable, and (2) evaluating the technical and scientific work that supports the
viability assessment of the Yucca Mountain site. I will now
briefly discuss some of the Board's conclusions and comments related to these
activities.
Some Conclusions from the Board's November 1998 Report
In
November 1998, the Board issued a report outlining its views about future
research needed for addressing uncertainties about the performance of the
repository system, including both the engineered and the natural barriers. The
Board concluded in the report that although there are economic and technical
limits to reducing uncertainties about the performance of the proposed
repository system, the Board believes that some key uncertainties could be
reduced further over the next few years through a focused research effort. One
important line of work is to evaluate alternative and potentially more robust
repository and waste-package designs. It is likely that improving these designs
could increase confidence in predictions about the performance of the
repository. Other key areas of research include work to obtain a better
understanding and estimation of seepage of water into repository tunnels and
transport of radionuclides through the saturated zone under the repository. The
Board notes that the DOE has undertaken work in all these areas, and we look
forward to the results of these scientific studies and engineering analyses.
The Board's conclusions from its November 1998 report served as a technical
basis for its review of the DOE' s viability assessment.
Preliminary
Comments on the VA
The Board's November report, along with the access to
information provided by the DOE throughout the development of the viability
assessment, make it possible for the Board to provide these preliminary comments
on this immense and detailed document. The Board's evaluation of the VA will be
completed in the next month or two.
I will begin with three general
comments.
First, the DOE deserves congratulations for completing the VA,
which is the most significant landmark thus far in the characterization and
evaluation of the Yucca Mountain site. The viability assessment
is a solid accomplishment that has enabled the DOE to integrate large amounts of
data and analyses, to establish a preliminary repository design, and to set
priorities for work that needs to be completed before making decisions about
site recommendation and licensing, if the site proves suitable. However, the
Board concurs with the DOE that the VA is simply a snapshot of the current state
of knowledge about the site; it was not intended to be and is not a suitability
determination.
Second, the Board's preliminary comments on the VA reflect
its views that (1) all uncertainty about the performance of a repository at any
candidate site cannot, and need not, be eliminated and (2) a "defense- in-depth"
repository design that includes both engineered and natural barriers is
appropriate in light of uncertainties about the projected performance of any
repository system over many thousands of years.
Third, because the Board did
not have the expertise and resources needed to review the cost estimates
included in the VA, it has no comment on their accuracy.Now, more specifically:
- The Board believes that, in general, the scientific studies summarized in
the VA were carried out in a manner that produced good scientific information.
The reports included in the VA are well written and clearly presented.
- It
is very hard to judge at this point how realistic the "bottom- line" estimates
of repository performance may be in the VA. In fact, DOE representatives have
stated that the VA's total system performance assessment (TSPA-VA) cannot be
used to assess compliance with the regulatory standard. Because of a general
lack of data supporting some critical assumptions in the mathematical models,
some of the assumptions in the TSPA-VA are likely to be overly conservative,
while others may be nonconservative.
- The VA relies quite heavily in some
cases on the formal elicitation of expert judgment. This was necessary and
extremely useful, given the lack of field and laboratory data in certain areas
and the equivocal nature of some of the data in other areas. As the experts,
themselves, pointed out, however, expert judgment should not be used as a
substitute for data that can be obtained directly from site, laboratory, and
other investigations.
- The VA helps illuminate the state of knowledge about
the three major barriers that will be necessary to achieve a defense-in-depth
approach to repository performance: the unsaturated zone, the engineered barrier
system, and the saturated zone. However, it is clear from the information in the
VA that there are significant and substantial uncertainties about the
performance of each of these barriers and about how they would work together to
provide defense-in- depth. As pointed out by the DOE, the TSPA-VA explicitly
acknowledges the need for defense-in-depth analysis but does not provide such an
analysis.
Closing
In conclusion, Mr. Chairman, the Board believes that
the Yucca Mountain site continues to merit study as the
candidate site for a permanent high-level radioactive waste repository and that
work should proceed to support a decision by the Secretary of Energy on whether
the site is suitable. However, significant uncertainties remain about the
performance of both the natural and the engineered barriers in a repository
system.
The VA is a significant accomplishment that enables the DOE to
identify and set priorities among key areas of research that could improve the
technical basis for making decisions about site suitability, site
recommendation, and licensing. However, the Board concurs with the DOE that the
VA was not meant to be, and should not be, viewed as a decision about the
suitability of the Yucca Mountain site.
The Board is
pleased to note that the research priorities presented in the VA are consistent
with those identified in the Board's November 1998 report and that much of this
work is already under way. Results of these scientific tests and engineering
analyses could help address the uncertainties about the performance of the
repository system.
Thank you for the opportunity to provide these
preliminary comments about the VA on behalf of the Board. I will be pleased to
respond to questions.
END
LOAD-DATE: February
11, 1999 
