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5
A Framework for Evaluating Waste Characterization
Activities
v ~ .
.
i
In this chapter, the committee describes the elements of an analytical framework
to evaluate the effectiveness of specific characterization activities by relating the
information gathered through waste characterization to the benefits it produces. The
chapter ends with simplified illustrative applications of the proposed framework.
5~1 Statement of the Problem
The U.S. Department of Energy's (DOE's) contact-handIed transuranic (CH-TRU)
waste characterization program is controversial. DOE as well as the New Mexico
Environmental Evaluation Group (EEG) and previous National Research Council
committees have suggested that some characterization activities are too extensive,
costs are too high, and some of the information gathered is not used to make any
decision related to the protection of human health and safely or the environment. On the
other hand, stakeholders in New Mexico have argued that all the current characterization
activities are necessary to ensure an adequate level of protection.
DOE has informed the committee of its intention to propose changes to the
characterization program to eliminate or modify activities that do not have an impact on
human health and safely or the environment. However, as discussed in Section 5.3,
DOE did not provide the committee with a formal analysis of the impacts of altering
specific characterization activities on costs or on risks to the public, workers, or the environment.
DOE is responsible for making the policy decision to seek regulatory approval for
changes to a particular characterization activity. In the committee's view, a structured
and quantitative analysis is necessary to determine whether a change to the
characterization program is warranted and to justify proposed changes with the
regulator~s), state and local officials, and the general public (see Recommendations 1, 5,
and 6 in Chapter 6~. In this chapter, the committee provides the elements and illustrative
applications (albeit incomplete) of a proposed structured and quantitative analytical
framework that could be used to evaluate changes to specific characterization activities.
5.2 An Overview of a Proposed Analytical Framework
Below, the committee presents the elements of a generic analytical framework
that could be used to iclentify changes to specific characterization activities. The purpose
of the proposed analytical framework is to determine the value of the characterization
information obtained through a given characterization activity. If the information is used
to make decisions about waste handling, transportation, or disposal, then it has an
impact on the outcome of these decisions (for instance, on reducing risks, uncertainties,
costs, or delays), and thus it has value in the present context. On the other hand, if the
characterization information is not used in current or future decisions, then it has no
impact, and therefore it has no value. These are the two extremes. In most cases there
58
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A Framework for Evaluating Waste Characterization Activities
59
is some value,4 but the question is whether costs to obtain the information exceed the
benefits it produces.
Figure 5.1 shows a general flow diagram of the characterization and decision-
making process. Boxes represent decisions by DOE, such as the decision to review a
characterization activity in the current characterization program or to request a permit
modification for the Waste Isolation Pilot Plant (WIPP). Ovals represent outcomes of
these decisions. The current waste characterization program is composed of
characterization activities (see Section 4. ~ ~ that generate a flow of information about the
wastes. Some of this information is used to make decisions, such as whether to remove
prohibited items or to vent a canister prior to transportation. The characterization
activities, along with the decisions made on the basis of the information gathered, lead to
impacts in terms of risks to workers and the public, costs, and public concerns.
Feedback loops represent updating and improving characterization activities
through experience, data collection, and analyses. Experience and learning lead to ideas
for improvement, by eliminating unnecessary characterization activities, finding more
cost-effective2 solutions, or by adding activities to further reduce possible risks. Once
these possible improvements are identified, they form the basis for a permit modification
request, which is submitted to the appropriate regulatory agency. The regulatory agency
decides whether the proposed change is still in compliance with the regulations and
approves or declines request. Within this framework, DOE would communicate
interactively with stakeholders about proposed changes to the program and stakeholders
would provide input. Stakeholder input could be provided informally during public
information exchange meetings (such as the WIPP's quarterly meetings), or formally,
through a public comment period during the regulatory process. Stakeholders concerns
are part of DOE's analysis to determine whether a permit modification is warranted (see
Section 5.6~.3
Within this framework there are several opportunities for structured and
quantitative analyses of the value of the characterization information. First, in applying
this framework, the characterization information could be recorded and analyzed to
determine how the characterization information is used and whether it is used frequently,
rarely, or never. For example, information on volatile organic compounds (VOC) or
instances of identified prohibited items in waste drums could be recorded and its impact
on decisions to vent canisters or to remove prohibited items could be analyzed.
Second, the impacts of the characterization information on the decisions made
on the basis of this information could be analyzed in terms of their combined impact on
risks, costs, and other aspects of the characterization program. For example, the risks of
transporting canisters with high VOC levels or with prohibited items could be analyzed to
determine the risk reductions achieved by characterization. By comparing risks, costs,
and other impacts, such as policy and societal impacts, with and without characterization
information, the proposed analytical framework can establish the value of
characterization information.
Similarly, this analysis can support proposed changes to the characterization
program by showing that alternative characterization activities are more cost-effective
than the current ones. The analytical framework proposed here denves from a decision-analysis
For example, characterization information is used in preparation and archiving of a
record of characterization activities and may have value in that context.
2For a definition of cost effectiveness, see Section 5.7.
Mechanisms for stakeholder participation in decision-making have been discussed by
other National Research Council committees (NRC, 2003 and references therein).
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60
_ ~
Decisions based on
Characterization Information
~ Risks, Costs, and
an,\ Other Impacts
~ ' ~
Stakeholder
Input
,
1
I Permit Modification
Request
. . .
\/ Regulator's ~ ? ~:
~ Decision J L
Improving the Characterization Program for Contact-Handled Transuranic Waste
Current Characterization
Activity/Program
.
Information Generated by - \ / Experience andAnalysis-
Characterization A ~ Based Learning
Revised Characterization
Activity/Program
FIGURE 5.1 Features of the proposed analytical framework. Boxes represent decisions;
ovals, outcomes; and arrows, the dependencies between them. The dotted line indicates
uncertainly in the regulatory decision. The double-headed arrow represents interactive
communication. For an explanation of the figure, see text.
too! called the Value of Information.4 Other analytical approaches have elements in
common with the proposed framework, such as the Data Quality Objectives approach
proposed by the U.S. Environmental Protection Agency (EPA) (2000~.
An analysis of the effectiveness of characterization activities addresses not only
risks and costs, but also programmatic impacts (e.g., delays in processing wastes) and
policy and societal impacts (e.g., need for an authorizing document modification request
or a shift in public perception clue to a change to the program). These impacts and
suggestions for how to address them within this analytical framework are discussed
below.
5.3 Assessment of the Risks
The first type of analysis in the proposed analytical framework is risk
assessment. In the present context, the purpose of risk assessment is to determine the
link between waste characteristics and risks related to handling, transportation, and
disposal of CH-TRU waste at WIPP. The assessment of risks takes into account risks at
a "micro" level (e.g., risks to workers gathering characterization information) anti at the
"macro" level of the National TRU Waste Management Program (e.g., risks incurred at
4For example, see Clemen and Reilly (2001~; Winkler (2003~; and, for an application to
the characterization of Hanford tank wastes, see Fassbender et al. (1996~.
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A Framework for Evaluating Waste Characterization Activities
61
the site, during transportation, and at the WIPP facility). Non-technical risks, such as the
risk of decreased public confidence, are also important in the proposed analysis.
Waste characteristics that affect health and safely are the most important to
characterize. If a characterization activity produces information on waste characteristics
that are not linked to human health and safely or the environment, then there are no
programmatic decisions to be made with respect to those characteristics.
The risk assessment also determines the accuracy and precision needed in
knowing a given piece of characterization information. Uncertainties in each analytical
measurement are considered and propagated through the analysis so that risks are
weighted by the propagated uncertainties. Each estimate of risk therefore has an
uncertainly assigned to it. Risks with large uncertainties indicate that those
characterization activities that define that risk need more consideration and attention
unless the risks themselves are of lithe consequence. Such an analysis may indicate
that more characterization is needed or that different characterization activities should be
explored. Estimates of risks for which the uncertainties are small indicate that a higher
degree of confidence exists for those parameters, and perhaps less analytical data are
needed or could be justified.
When assessing risks and how they are impacted by characterization
information, it is important not only to consider routine and expected situations, but also
to inquire how the characterization information might be used in unusual and
unanticioated or low orobabililv circumstances. Several situations in which
, .
~ . _ · _ _~ ~ ~ _e B_ _ _ ~ _ B_ ~ _ _ _ _ ~ ~ . _ _ ~1 ~ ~ ~ _ : . . . _ _ 1 _
characterization data COUIO ne valuable can oe envisioned. Nor example, IT WaSIe
emplaced in WIPP must be retrieved, characterization information might become useful.
In addition, different or additional characterization information may become useful for
future, as yet undefined, waste streams. Risks in accident conditions would take into
account the probability and magnitude of the consequences for each accident scenario
in which characterization information could be useful.
DOE has prepared several analyses containing elements of risk assessments
that were submitted to WIPP's regulatory agencies to authorize operations at the WIPP
facility. For instance, the EPA Certificate of Compliance relies on an evaluation of a
performance assessment which includes elements of risk assessment (DOE-CGA,
1996~. The Lancl Withcirawal Act requires an analysis of the environmental impact of
WIPP operations (DOE-WAC, 2003) and a Safely Analysis Reports (DOE-SAR, 2003~.
DOE has also concluctecl safely analyses and performance assessments in connection
with transportation of wastes to WIPP (DOE-SARP, 2003~. Many of these studies are
now being updated to reflect recent data and experiences and are periodically
reevaluated.
Although DOE has performed analyses of many aspects of operations related to
WiPP performance, including transportation, the committee could find no studies that
explicitly, systematically, and quantitatively link its waste characterization program to
risks to the public, workers, or the environment (see Finding and Recommendation ~ ). In
particular, DOE has not used the studies mentioned above to estimate quantitative
relationships between current or planned characterization activities and risks. DOE
5The WIPP Safety Analysis Report, required by agreement with the State of New Mexico,
documents the adequacy of safety analysis to ensure that a facility can be constructed, operated,
maintained, shut down, and decommissioned safely and in compliance with applicable laws and
regulations. The report is based on the facility's safety analysis, which is a documented process
that: 1) provides for the systematic identification of hazards within a given DOE operation; 2)
describes and analyzes the adequacy of measures taken to eliminate, control, or mitigate
identified hazards; and 3) analyzes and evaluates potential accidents and their associated risks.
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Improving the Characterization Program for Contact-Handled Transuranic Waste
provided cost information for ongoing characterization activities but the committee could
not find any discussion of the costs and benefits of current characterization activities
compared to alternative ones.
The committee is not aware of any analysis showing the risks of handling,
transporting, or of disposing of some of the prohibited items listed in the Hazardous
Waste Facility Permit (HWFP). Such items are currently handled by workers when they
are identified in waste characterization and removed from waste streams to attain
compliance. To the best of the committee's knowledge, DOE's risk assessments
address only waste characterized in compliance with Waste Acceptance Criteria and
HWFP requirements. In these risk assessments it is assumed that waste characteristics
, ~
,
are known based on the current characterization program. For instance, the
performance assessment submitted for EPA Certification is based on the assumption
that waste activity and volume are within the limits established in the Land Withdrawal
Act and that the waste does not contain any water or other prohibited items.
Only recently (September 2003) has DOE submitted to the committee studies
that could be viewed as the initial elements of an analytical approach in connection with
a request for a chance in the headscace Gas samolino-related activities (Boalwriahi.
. ~ , ~ . ~ ~ ~ ,
2003; Myers, 2003; and McCutia and Van Soest, 2003~. These studies include en
evaluation of WIPP room-based VOC monitoring as an alternative to analyzing the
headspace gas of each drum. Additional material submitted address Data Quality
Objective-related issues, and the accuracy of Acceptable Knowledge (AK) on waste
characterized to date (HWFP, 2003; Kehrman and Most, 2003~.6
Examples of issues to be included in the proposed analytical framework to
determine the linkage between waste characteristics and risks in handling,
transportation, and disposal of CH-TRU waste at WIPP can be found in Appendix F.
Risks considered are the following:
risks related to waste handling;
risks related to transportation; and
risks related to waste disposal.
Within its constraints of time and information, the committee could only point out
some of the risks to be included in this analysis; a complete risk assessment is a major
endeavor that the committee was not prepared to undertake.
5.4 Costs of Waste Characterization
Analysis of the impacts of waste characterization on costs would include "hard"
as well as "soft" costs. Hard costs are the costs associated with gathering
characterization information. Table 4.1 shows that the most expensive characterization
activities involve breaching waste containers and waste analyses. This is due to the
~ _ ~ . _ . _
costs of protecting workers from radiation. Other hard costs Include: costs of equipment,
data management, overhead costs (including that for quality assurance),
characterization method certification, staff training, record keeping, as well as the costs
of submitting a permit modification.
Soft costs are costs that are difficult to quantify, such as the costs associatecl
with a possible loss of stakeholder confidence; the costs of delaying shipments to WIPP
if the permit modification request is denied; or costs incurred in the case of an accident
6NMED found that these analyses lack correlation between the characterization issues
associated with waste emplaced to date and the remaining inventory projected for disposal at
WIPP (NMED, 2003c).
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A Framework for Evaluating Waste Characterization Activities
63
(e.g., costs of cleanup if reduced characterization information leads to an accident during
waste handling, transportation, or disposal).
According to DOE's cost analysis, it is not possible to predict whether
characterization costs will increase or decrease with time:
A comparison of the unit costs developed [beivveen October 2002 and
June 2003] showed no significant trend (either up or down) for unit costs
over time. While some costs did in fact decrease, others increased. Many
factors impact the costs, some of which cannot be controlled, or reduced,
at the activity level. In some cases, a reduction in quantities may even
lead to an increase in unit cost.
Site-specific priorities such as stakeholder interaction, or regulatory
impacts, directly impact unit costs. Increases or decreases in facilities and
infrastructure costs affect the cost structure relating to characterization
activities. Sites differ in the types and amounts of TRU waste, schedules
for shipping, contractual agreements for characterization, and the maturity
of the program. All of these factors, whether positive or negative, affect
the total costs. While processes may be streamlined and shipping
procedures made more efficient, costs may not be reduced
proportionately. Therefore, reducing future costs must be pursued in other
areas, such as regulatory relief and technology development (DOE-
CABE, 2003; page 23~.
~ s _ · · _ -
-
The committee believes that, as the experience base continues to grow, it is
possible to analyze costs sufficiently to produce at least a credible and useful prediction
of cost trends under the most likely scenarios. Changes to the characterization program
that would improve the characterization process, together with an expanding operational
experience base, could help reduce both risks and costs. However, if new and more
difficult or complex waste types have to be dealt with in the future (see Sections 2.3 and
2.4y, or more stringent cleanup standards are imposed by the regulators, then
characterization costs could increase.
Scenarios in which characterization needs and costs may increase are the
following:
radiographic techniques and other special characterization techniques and
technologies for large containers may have to be developed and may cost more
than the observed costs to date;
remote-handIed transuranic waste with dose rates greater than 1,000 rem per
hour may be authorized in WIPP possibly requiring additional worker protection
measures;
previously buried TRU wastes may include more compromised containers
requiring more elaborate handling procedures;
future waste streams may require new or different characterization information;
additional TRU waste not accounted for in current inventories may be approved
for disposal in WIPP increasing total characterization, transportation, and
disposal costs; or
characterization requirements may be added or strengthened for public
confidence purposes, in particular if an accident occurs.
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Improving the Characterization Program for Contact-Handled Transuranic Waste
Changes to the characterization program also have an impact on the schedule.
The proposed analytical framework would consider time and effort required to: acquire
alternative characterization information (to the required accuracy and precision); manage
the data (including quality assurance activities at the data generation level and project
management level); prepare a permit modification request; obtain approval of the
modification, obtain certification; and train personnel to use new characterization
equipment.
5.5 Policy Impacts
Most7 changes to the characterization program must be approved by the
regulator~s) to ensure continued regulatory compliance. Regulatory compliance is
grounded in risk considerations. Regulatory requirements are derived from assessments
of the risks to the public, workers, or the environment and the need for records
documenting waste characteristics, waste characterization activities, and oversight of
related operations. Therefore, while characterization is not a risk assessment in itself, its
purpose is to provide information used in determining if criteria derived from risk
assessments have been met.
DOE and its regulators worked to translate the intent of various environmental
laws (such as the Land Withdrawal Act, the Resource Conservation and Recovery Act)
into specific regulatory requirements for waste characterization. These regulatory
requirements are set forth in 40 CFR 194, the HWFP, and the Certificate of Compliance
for transportation packages (see Chapter 3 and Appendices C and E).
The details of characterization activities are prescribed in W! PP's Waste
Accectance Criteria and in the HWFP. The Waste Acceptance Criteria can be modified
... . . . . . . . . ,.. . ... _ _ ~ .. . . .
Without regulatory approval It changes are not In contact with Thea, New Mexico
Environment Department (NMED), or U.S. Nuclear Regulatory Commission (USNRC)
regulations; any change to the HWFP has to be approved by NMED.
Experience shows that requests for authorization document modification are
most likely to be approved if they are supported by careful analysis and detailecl recorcis
of characterization experience. As a result of substantial interactions with the regulators
and thorough technical justification in specific areas, DOE has succeeded in obtaining
many revisions of the WIPP program thus far (see Chapter 3~.
The political feasibility of a change in the characterization program is a further
element to be considered in the impact analysis. The HWFP is the only direct control
that New Mexico has on the characterization process and WIPP operations. Any
proposed change to the characterization program wit! be examined carefully by the state
with regard to its effects on previous agreements and on the state's role in regulating
WIPP.
Moreover, continuing to use the established regulatory processes for making
changes to the characterization program couicl help build cooperation and confidence
among all parties (see Finding and Recommendation 6~. The proposed analytical
framework could be used to make a technically defensible case before the regulator and
the public that a given change to the program is still protective of human health and the
environment. The regulator would make the final determination whether the proposed
change would still lead to compliance with regulations.
7Some changes to characterization activities are under DOE's purview, such as the
addition of fast-scan radiography at the Savannah River Site to screen for prohibited items (see
Section 4.3~.
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A Framework for Evaluating Waste Characterization Activities
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5.6 Societal Impacts
Although societal impacts are difficult to quantify, the impact of a change to the
characterization program on stakeholder confidence in DOE, not only in New Mexico,
but also in generator and corridor states, cannot be ignored (see Findings and
Recommendations 5 and 6~. The public, state and tribal officials, and organizations such
as the Western Governors Association and citizen's groups watch the permit
modification process closely. Evidence suggests that some members of the public and
state officials lack trust in DOE. Some stakehofJer concerns are listed in Section 4.6.4.
Unless supported by technically defensible analyses showing that no increase in
health, safety or environmental risk will ensue, a request for change in a permit may be
interpreted as leading to a decrease of safely, with concerns of increased risk to
workers, the public, and the environment.
Changes to the characterization program that would accelerate waste shipment
to WIPP (or elsewhere) may be popular at generator sites from which the wastes would
be removed. However, they may have a negative societal impact in the recipient state,
New Mexico, or in corridor states through which waste is transported, if it is believed that
such acceleration reduces safely.
Providing a defensible and credible technical analysis and characterization
record to the public in support of programmatic changes could build confidence that the
changes do not weaken protection of human health, safely or the environment, and help
avoid charges of secrecy that might otherwise be made. Characterization information
could be disseminated in a variety of ways, including through published reports, public
access to the WIPP Waste Information System, or summaries thereof.
The analytical framework proposed by the committee, or any comparable
analysis produced in an open and responsive process, can help reduce or mitigate any
lack of trust and lead to greater tolerance of changes, where warranted. The societal
impact of changes to the program, provided they are technically defensible, may even be
positive overall in light of savings in taxpayer dollars.
5.7 Cost-Effectiveness Analysis
To determine whether a characterization activity has value, information on the
risks, costs, and other impacts with and without the characterization activity is needed.
For example, to determine the value of headspace gas sampling and analysis and how it
reduces risks, data on the flammability and risks of worker exposure to high VOC
concentrations if headspace gas sampling did not occur are necessary.
There is a simple rule to identify which characterization activity needs to be re-
evatuated through a structured and quantitative analysis: if the information gathered by
this activity is never used for making decisions about waste handling, transportation, or
disposal, it has no value. This is because the risks, costs, and other impacts of this
characterization activity would be the same without collecting this information. Ultimately,
the choice of modifying or eliminating a characterization activity from the program
depends on a cost-effectiveness analysis.
Proposed changes to current characterization activities could be justified by
clearly demonstrating that the changes improve the program in the following ways:
1.
the proposed change is less expensive, involves less worker risks, less public
risk, and less other impacts than the current characterization activity;
2. the proposed change is less expensive or has less worker risks or both and has
the same public risks and other impacts than the current characterization activity,
particularly if the current characterization activity generates information that is not
used for decision-making purposes; or
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Improving the Characterization Program for Contact-Handled Transuranic Waste
3. the proposed change costs much less or has much less worker risk or both and
affects public risk and other impacts in a minor way.
The first case is the most convincing one: there is no reason to reject a change
that is better in all aspects. The second case involves a cost-benefit analysis that
determines whether it is possible to obtain the necessary information for less cost and
worker exposure. The third case is the most complex one, since it requires quantification
of the terms "much" and "minor," which is usually done in a cost-effectiveness analysis.
A cost-effectiveness analysis differs from a cost-benefit analysis in that the
former relates the money spent to the benefit (in whatever units) gained, while the latter
requires that all costs and benefits be expressed in monetary terms. Cost-effectiveness
does not require monetization of "effectiveness," just quantification of a measure of
effectiveness. Cost-effectiveness quantifies all costs as direct costs and all benefits or
effectiveness measures in non-monetary terms. This allows making judgments about
whether it is worth spending an incremental amount of money for an incremental amount
of "effectiveness" without assigning dollar values to the effectiveness measure. In this
context, a cost-effectiveness analysis allows assessment of a broader range of impacts
(including soft costs, policy, and societal impacts) without attaching monetary values to
them.
; . ~
5.8 Implementation Considerations
The proposed analytical framework is conceptually powerful, but demanding in
practice. A technically complete, formal cost-effectiveness analysis, as defined in risk
and decision analysis, requires a "well-defined problem." That is, the decisions and
outcomes are defined, an appropriate "measure of value" for the problem is specified,
the relevant measurable parameters are identified, and the degree of certainly or
knowledge about each of these is quantified. The complete and formal application of
such an analysis requires that: first, the connections between waste characterization and
impacts to workers, the public, and the environment be identified; second, that actual
information about risks, costs, worker exposure, and benefits of characterization
information be available; and third, that all consequences (environmental, health,
programmatic, policy, and societal risk, costs, and benefits) be converted into a single
number specifying equivalent cost or utility.
Given its complexity, a complete analysis of the benefits and costs of each waste
characterization activity is beyond the commidee's capability in this study. In any event,
neither DOE nor the regulators provided any information on the linkages between
characteristics, waste characterization activities, and protection of human health and
environment. The committee also had limited information on worker doses associated
with some specific activities. Absent the linkages between waste characterization and
system performance, the committee could not identify specific changes to
characterization activities.
To identify the most promising areas in which to evaluate the effectiveness of the
characterization program, a less elaborate analytical framework than the one described
above can be used. If an alternative characterization activity is compared to the current
one, and the alternative is found to be better from the point of view of risk and cost and
at least equal on all other parameters, then these activities are candidates for a
quantitative cost-effectiveness analysis.
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5~9 Applications
Based on the information provided by DOE and on findings by a previous
National Research Council committee, three characterization activities appear to be
candidates for re-evaluation using the proposed analytical framework:
1. headspace gas sampling and analysis;
2. homogeneous waste sampling and analysis; and
3. visual examination to confirm radiography results.
,
According to the information gathered by the committee, these three
characterization activities are carried out with their current sampling frequencies mainly
for regulatory compliance and do not appear to directly reduce risks or costs. These
activities could be analyzed through the proposed analytical framework to determine
their value and impacts, and whether there are alternative characterization activities (or
modifications to the current one, such as different sampling frequencies) that would still
be in compliance with regulations and whose risks and costs to gather the information
would be more commensurate with the risks entailed. If the alternative has positive
impacts on risks and costs, as well as on policy and societal factors, then DOE may
decide to apply for a permit modification.
For each example below, the committee attempts to analyze the value of the
characterization information qualitatively. The information and conclusions provided are
based on information gathered during the study. Different, more appropriate examples
might become evident if a more complete risk and impact assessment were
implemented.
5.9.1 Headspace gas sampling and analysis
Heacispace gas sampling and analysis was chosen as an example on the basis
of information submitted by DOE, on cost considerations, and on the findings of a
previous National Research Council committee. Although not the most expensive activity
per unit cost, headspace gas sampling and analysis is one of the most expensive
activities when averaged on the entire waste inventory because it involves sample
collection and analysis on 100 percent of waste containers. During information gathering
meetings, DOE has publicly stated that this activity is performed only to ensure
compliance with the HWFP.
A previous National Research Council committee found that there was no
specific regulatory requirement in the Land Withdrawal Act, the Resource Conservation
and Recovery Act, or in 40 CFR 264 to sample headspace gases in the totality of waste.
DOE proposed to NMED to do so while drafting the HWFP application (NRC, 2001~.
NMED accepted the proposal and this characterization activity is now codified in the
HWFP and therefore has become a regulatory requirement. The HWFP now mandates
that the concentration of 29 VOCs be measured in all drums (see Section 4.3 for
exceptions) before shipment to WIPP to ensure that their concentration in WIPP waste
disposal panels is within the limits allowed in the HWFP.
The alternative characterization activity considered by the committee is room
monitoring in WIPP for VOCs coupled with flammability tests at generator sites for
compliance with transportation regulations. The suitability of this alternative activity could
be perioclically checked by headspace gas sampling and analysis on a statistical basis.
VOC concentrations in W!PP are currently monitored in W!PP's exhaust shaft, as
required in the HWFP, to confirm the absence of VOC release into the repository.
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.. . .
Improving the Characterization Program for Contact-Handled Transuranic Waste
5. 9. 1. ~ Assessment of risks
This characterization activity is designed to help assess risks from the presence
of VOC in W! PP above the allowable limits, presence of flammable gas above
flammability limits during shipping and handling drums in W! PP, and presence of
hazardous compounds in WIPP not identified with AK. The objective of headspace gas
sampling and analysis is to prevent shipment of flammable or explosive gases, exposure
of WIPP workers to VOC concentrations above applicable limits, and VOCs release in
the atmosphere. Room sampling would measure directly VOC concentrations in WIPP.8
Flammability limits could be tested at generator sites using alternative characterization
methods to track hydrogen and methane (for example using gas chromatography with a
flame ionization detector).
The proposed alternative characterization activity would produce equivalent risk
information in a potentially more reliable fashion. According to DOE, VOC concentrations
measured in the stagnant air behind the curtain used to isolate each disposal room after
it has been closed correlate well with results from headspace gas sampling and analysis
at generator sites (Boalwright, 2003~. Therefore, this method could be used instead of
headspace gas sampling and analysis at generator sites. However, the information
would be at a different level of specificity, as current headspace gas sampling and
analysis provides data on each drum, while room sampling would not identify individual
container sources for any VOCs detected.
5.9.1.2 Value of characterization information
The concentrations of the 29 VOCs in each drum are used to project VOC
concentrations in WIPP and to confirm AK by comparing the VOCs found in the
headspace gas to those expected from historical knowledge of the waste. In its review of
CH-TRU characterization activities, the EEG writes (EEG, 2003b; page 28~:
[Headspace gas sampling and analyses] do provide additional information
on the contents of waste containers. Additional waste streams have been
defined because of the results of these analyses, and on occasion
additional RCRA [Resource Conservation and Recovery Act] hazardous
waste numbers have been added to waste streams. The importance of
these functions has occasionally been denigrated, primarily because this
additional information is not used to control quantities of VOCs coming to
WIPP other than to show compliance with the room based concentration
limits. [...]
This information is used (in conjunction with acceptable knowledge) to
assign hazardous waste numbers to each container. However, EEG is not
aware that these hazardous waste numbers are used to exclude waste
from the WIPP or to otherwise control the hazardous waste. These data
probably provide the incidental benefit of confirming AK and ensuring the
various Waste Acceptance Criteria (WAC) requirements for stability of
waste are met.
The EEG believes that it is desirable to maintain a comprehensive headspace
gas sampling and analysis program for CH-TRU wastes as an additional confirmation
method for AK. However, it adds (EEG, 2003b; page 58~:
To date, VOCs have not been observed in the exhaust shaft at WIPP, due both to the
high rate of air flow through the mine and because waste received to date has contained low
levels of VOCs in the headspace gas.
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A Framework for Evaluating Waste Characterization Activities
it should be possible to require less than 100°/O sampling in some cases.
Our primary concerns are with organic sludges and older waste
containers where information may be less reliable.
69
Headspace gas data and records are also used to ensure that the concentration
of flammable gases (in particular, methane and hydrogen) does not exceed flammability
limits for transportation purposes. Headspace gas information affects transportation
decisions (e.g., purging the container prior to transportation) and consequences (e.g.,
the risks and possible consequences of deflagration during transportation). The
information gathered with the alternative characterization method could be used to make
the same decisions about transportation as above.
5.9. ].3 Cost impacts
Details on the efforts and costs to obtain the headspace gas sampling and
analysis are in Chapter 4. The sampling and analysis requires approximately 4.4 person-
hours and costs, on average, $620 per waste container. Most of the characterization
effort and time is due to the data management for 29 VOCs. DOE informed the
committee that, although reliable cost estimates are not available, the technical effort to
obtain hydrogen and methane concentrations through gas chromatography using a
flame ionization detector is similar, in terms of equipment and time, to that for VOCs
(Nelson, 2003~. However, the data management effort is substantially lighter because
there are only 2, rather than 29, VOCs to track. The same quality assurance
requirements apply to the monitoring of VOCs in WIPP, as established in the HWFP.
5.9. 1.4 Policy impacts
Any change to the headspace gas sampling and analysis activity requires a
HWFP modification. In several occasions, NMED has stressed the importance of this
characterization activity to satisfy the regulatory requirement of 40 CFR §264.~3(a)~1 ~ to
"obtain a detailed chemical and physical analysis of a representative sample of the
wastes" before such waste is accepted for disposal. NMED has provided comments to
the committee on the DOE's analyses supporting the request for relief from this
characterization activity. According to NMED, DOE did not go far enough in the analysis
of the relationship between VOC data of waste emplaced thus far and those of future
waste streams (NMED, 2003c; cover leHer):
tthe conclusions reached in the AK accuracy analysis] do lithe to address
the uncertainties associated with older, poorly documented waste
streams generated fifteen to thirty years ago that have yet to be
characterized.
The committee believes, based the information it has received, that the proposed
alternative can be shown to be in compliance with regulations and to ensure the same
level of protection of human health and the environment as the present characterization
activity. Should VOC concentrations measured in disposal rooms begin to rise, steps
(e.g., increasing ventilation rates) can be taken to control worker exposure or releases to
the atmosphere. Concerning the policy impacts on transportation requirements,
flammability characteristics of waste can be monitored by any method or equipment that
complies with the quality assurance requirements (calibration, records, training, and so
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Representative terms from entire chapter:
characterization activity
70
Improving the Characterization Program for Contact-Handled Transuranic Waste
forth) listed in the Quality Assurance Program Plank However, a change in the
flammability test may require a modification to the USNRC Certificate of Compliance for
shipping containers.
,
5.9. 1.5 Societal impacts
According to the records of public comments to HWFP modifications,
stakeholders in New Mexico have reacted strongly to proposed changes to the
headspace gas sampling and analysis requirement. Their concern is that any change to
this requirement could jeopardize the protection of human health and safely and the
environment (Nuclear Watch of New Mexico, 2002~. A change to this requirement, if not
fully supported by a structurecl, creclible, and quantitative analysis, could cause a loss of
confidence, in particular in the case of an accident involving VOCs or hazardous waste
components that were not detected prior to shipping the waste to WIPP. Corridor states
also need assurance that the proposed alternative does not increase transportation
risks.
5.9. 1.6 Cost-effectiveness analysis
The following cost-effectiveness analysis for this characterization activity is only
qualitative and is based on partial information received by the committee during this
study. The purpose is simply to illustrate the use of the value of information framework in
a structured and quantitative analysis of characterization activities. Based on the
comparison between the status quo (headspace gas sampling and analysis) and the
proposed alternative, it appears that the information on VOC concentrations obtained at
generator sites is redundant with that obtained through WIPP disposal room monitoring,
could potentially be less reliable, could be obtained with a cheaper alternative, and
therefore has low value. In other words, the value of the information gathered with the
proposed alternative appears to be higher.
In situ monitoring coupled with measurements of hydrogen and methane at
generator sites for transportation regulation purposes is a more cost-effective solution
that could ensure the same, or a potentially higher level of protection of human health
and the environment. Moreover, the committee believes that EEG and NMED concerns
with organic sludges and older waste containers can be addressed with the proposed
alternative.
To decide whether a permit modification would improve the program a more
complete analysis is needed in which the advantages of using the alternative
characterization activity are considered along with the cost, time, and effort to prepare a
permit modification request to NMED (and possibly a USNRC Certificate of Compliance
modification), as well as with the risks of decreasing the confidence of the public in New
Mexico and that of corridor states in the safely of WIPP operations.
5.9~2 Homogeneous waste sampling and analysis
Homogeneous waste sampling and analysis is the most expensive unit
characterization activity even though it applies to only a small fraction of the waste (see
Table 4.~ ). A previous National Research Council wrote the following about this
requirement (NRC, 2001; page 80~:
9The requirements for gas testing are listed in the "Quality Assurance Program Plan for
the Gas Generation Test Program" (available at
A Framework for Evaluating Waste Characterization Activities
No operational decisions are made based on these data; that is, the
results of the sampling and analysis do not affect how waste is handled'
so it is not clear what justifies the additional radiation exposure risk and
cost of this procedure. In the committee's view, this sampling and
analysis applied only to homogeneous waste is unnecessary: If
acceptable knowledge documentation...provides sufficient characteriza-
tion information for heterogeneous waste, the committee can identify no
technical reason why acceptable knowledge should not also be adequate
for homogeneous waste.
,
..
71
The proposed alternative is a reduction or elimination of homogeneous waste sampling
and analysis to confirm AK.
5.9.2. ~ Assessment of risks, costs, anc] other impacts
According to the HWFP, the risks addressed by this characterization activity are
related to the potential toxic characteristics of homogeneous waste due to the presence
of metals or other hazardous compounds. Risk information is needed to determine the
health and safely consequences to humans or the environment related to the sampling
and analyses of homogeneous waste. Details on the efforts and costs of performing
homogeneous solids sampling and analysis are in Chapter 4. Characterization data
produced involve measuring the concentration of 30 VOCs. 11 semi-VOCs. and 14
metals. Other hazardous components may be added to the characterization data
requirements for a waste stream if they are found in more than 25 percent of the sample
for a Given waste stream. To the best of the committee's knowledge' the information
~;~ ~Z~ ,
acquired through this characterization activity is not used to make any decision on
handling, transportation, or disposal of CH-TRU wastes.
Table 4.1 shows that this is the most expensive characterization activity (on
average) because of the need to prevent contamination of workers and of the workplace
during sampling (drilling into the solid waste) and analyses.
r ~ ~ ~ ~ ~
I hese waste
characterization activities require from 8 to 40 person-hours and cost an average of
$87,000 for each unit on which they are performed. That averages to $430 per waste
container for the sampling and analysis over all units characterized.
A change in this characterization activity would require a HWFP modification.
Previous modifications to this requirement have already been approved by NMED (see
Section 3.3~. These changes concern statistical quality control methods, quality control
requirements for two semi-VOC analyses, and the reduction from three to one sample
from each core (EEG, 2003b). A societal impact of a change to this characterization
activity has a potential to decrease of public confidence in DOE particularly if an accident
occurs during handling, transportation, or disposal of uncharacterized homogeneous
waste.
5.9.2.2 Cost-effectiveness analysis
It appears that the information gathered with homogeneous waste sampling and
analysis has low or no value. In that case, reducing or eliminating this activity could
reduce costs without affecting the protection of human health and safely and the
environment. The New Mexico Environmental Evaluation Group independently reached
the same conclusion and wrote (EEG, 2003b; page 60~:
The EEG continues to believe that the homogeneous sampling and
analysis are unnecessary waste characterization requirements in the
HWFP. Our principal reason for this position is that the data are not used
72
Improving the Characterization Program for Contact-Handled Transuranic Waste
for any additional regulatory control (metals releases from accidents or
long-term processes would be controlled by radionuclide control
requirements and VOCs and semi-VOCs by theadspace gas sampling
and analysis] or the Confirmatory VOC Monitoring Plan).
To decide whether a permit modification would improve the program, the
advantages of performing less or no homogeneous waste sampling and analysis are to
be considered along with the time and effort to prepare a permit modification request to
NEED, as well as with the risks of decreasing the confidence of the public in New
Mexico and that of corridor states in the safety of WIPP operations.
5.9.3 Visual examination to confirm radiography results
Visual examination as a quality control check on radiography results on existing
waste (or reirievably stored waste, according to DOE's terminology) is the second most
expensive activity per unit container. A previous National Research Council committee
wrote (NRC, 2001; page 80~:
there is no requirement fall {air '`~ri~i~ti~^ ~{ real lows r-~i~r~h``
, IVI Vail Ill~aLlUI I Vl I OOl-Lll 11= 1 O~lV8l Oral Iy
results.... line visual examination confirmation is a self-imposed
procedure that yields no benefit but results in increased risk of exposure
and cost.
.
The proposed alternative is to decrease the size of the statistical sample or to
eliminate this activity completely to reduce waste handling.
5.9 3. ~ Assessment of risks, costs, and other factors
Visual examination provides information designed to assess risks related to the
hazard of mix-certification, that is the risk of handling and disposing waste that is not
suitable for transportation to and disposal at WIPP or estimating an erroneous waiting
time to comply with the drum age criterion. Experience gathered to date could provide
statistics on how often and which items were mix-identified using radiography, how often
visual examination has produced new information, or what is the test-retest or inter-
operator reliability of radiography operators. Risk information is needed on the impact on
human health and safely of mix-certification, miscalculating a drum age criterion or
material parameters weights. Information is also needed on worker exposure during this
activity to compare benefits and risks of performing this characterization activity.
Details on the efforts and costs to perform statistical visual examination to
confirm real-time radiography results for existing (or retrievably stored, in DOE's
terminology) waste are in Chapter 4. The information gathered through this activity is
used to determine the mix-certification rate and to verify the aging calculated by
radiography (the latter is done by visually examining the packaging configuration, type
and number of fillers, and inner layers of confinement). Operational decisions (i.e.,
whether to ship the waste or to open containers found within the waste) are also made
on the basis of visual examination information.
A change in this activity would require a HWFP moclification. As previously noted,
DOE has already obtained some relief from this requirement from NMED (see Section
3.3.2~. The societal impact of a change to this requirement couicl be a decrease of public
4°The committee referred to requirements in the Land Withdrawal Act, RCRA, Titles 40
CFR 191, 40 CFR 194, or 40 CFR 264. Visual examination is now a regulatory requirement
because it has been included in the HWFP.
A Framework for Evaluating Waste Characterization Activities
73
confidence in DOE particularly in case of an accident due to an overlooked item that
visual examination and segregation work could have eliminated.
5.9.3.2 Cost-effectiveness analysis
Y
Real-time radiography is generally an efficient and effective characterization
activity. Operators are trained to recognize prohibited items, although they cannot read
labels or estimate weights through radiography. This is done by opening the drums and
physically handling objects. Radiography is already a confirmation technique for AK;
visual examination is now a second type of confirmation. Given the high costs of this
activity, the potential for worker exposure, the existence of redundancies in the
characterization process to ensure that only waste complying with Waste Acceptance
Criteria is shipped to WIPP and the (apparently) marginal benefits of checking relatively
accurate radiography results on a small percentage of containers, it appears that visual
examination to confirm radiography results on existing waste has tow value.
Concerning this characterization activity, the New Mexico Environmental
Evaluation Group writes (EEG, 2003b; page 59~:
The [visual examination] process has the potential for slightly greater
radiation exposure than the other waste characterization requirements,
although the EEG has not been provided any data from the DOE to
indicate that exposures are significant enough to justify reducing the
requirement. The DOE has been successful in modifying the HWFP on
reirievably stored visual examination and this would be the preferred
process for seeking further reductions.
To decide whether a permit modification would improve the program, additional
risk information is neeciecl along with an analysis of the policy and societal impacts of a
change to this characterization activity.
