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Chapter 4 of the DOE Manual on Order 435.1, Low-level Waste Requirements, addresses
the procedures whereby Department of Energy LLW Disposal Facilities will operated
and maintained. Section P and Section
Q describe the Performance Assessment and Composite Analysis documents that
each DOE disposal facility will submit to the LFRG.
To view the entire DOE Order, Manual, and Implementation Guidance documents, choose
the link below to get to the main DOE Directives portal and follow the search requirements.
P. Disposal. Low-level waste disposal facilities shall meet the following requirements.
(1) Performance Objectives. Low-level waste disposal facilities shall be sited,
designed, operated, maintained, and closed so that a reasonable expectation exists
that the following performance objectives will be met for waste disposed of after
September 26, 1988:
(a) Dose to representative members of the public shall not exceed 25 mrem (0.25
mSv) in a year total effective dose equivalent from all exposure pathways, excluding
the dose from radon and its progeny in air.
(b) Dose to representative members of the public via the air pathway shall not exceed
10 mrem (0.10 mSv) in a year total effective dose equivalent, excluding the dose
from radon and its progeny.
(c) Release of radon shall be less than an average flux of 20 pCi/m2/s (0.74 Bq/m2/s)
at the surface of the disposal facility. Alternatively, a limit of 0.5 pCi/1 (0.0185
Bq/l) of air may be applied at the boundary of the facility.
(2) Performance Assessment. A site-specific radiological performance assessment
shall be prepared and maintained for DOE low-level waste disposed of after September
26, 1988. The performance assessment shall include calculations for a 1,000 year
period after closure of potential doses to representative future members of the
public and potential releases from the facility to provide a reasonable expectation
that the performance objectives identified in this Chapter are not exceeded as a
result of operation and closure of the facility.
(a) Analyses performed to demonstrate compliance with the performance objectives
in this Chapter, and to establish limits on concentrations of radionuclides for
disposal based on the performance measures for inadvertent intruders in this Chapter
shall be based on reasonable activities in the critical group of exposed individuals.
Unless otherwise specified, the assumption of average living habits and exposure
conditions in representative critical groups of individuals projected to receive
the highest doses is appropriate. The likelihood of inadvertent intruder scenarios
may be considered in interpreting the results of the analyses and establishing radionuclide
concentrations, if adequate justification is provided.
(b) The point of compliance shall correspond to the point of highest projected dose
or concentration beyond a 100 meter buffer zone surrounding the disposed waste.
A larger or smaller buffer zone may be used if adequate justification is provided.
(c) Performance assessments shall address reasonably foreseeable natural processes
that might disrupt barriers against release and transport of radioactive materials.
(d) Performance assessments shall use DOE-approved dose coefficients (dose conversion
factors) for internal and external exposure of reference adults.
(e) The performance assessment shall include a sensitivity/uncertainty analysis.
(f) Performance assessments shall include a demonstration that projected releases
of radionuclides to the environment shall be maintained as low as reasonably achievable
(ALARA).
(g) For purposes of establishing limits on radionuclides that may be disposed of
near-surface, the performance assessment shall include an assessment of impacts
to water resources.
(h) For purposes of establishing limits on the concentration of radionuclides that
may be disposed of near-surface, the performance assessment shall include an assessment
of impacts calculated for a hypothetical person assumed to inadvertently intrude
for a temporary period into the low-level waste disposal facility. For intruder
analyses, institutional controls shall be assumed to be effective in deterring intrusion
for at least 100 years following closure. The intruder analyses shall use performance
measures for chronic and acute exposure scenarios, respectively, of 100 mrem (1
mSv) in a year and 500 mrem (5 mSv) total effective dose equivalent excluding radon
in air.
(3) Composite Analysis. For disposal facilities which received waste after September
26, 1988, a site-specific radiological composite analysis shall be prepared and
maintained that accounts for all sources of radioactive material that may be left
at the DOE site and may interact with the low-level waste disposal facility, contributing
to the dose projected to a hypothetical member of the public from the existing or
future disposal facilities. Performance measures shall be consistent with DOE requirements
for protection of the public and environment and evaluated for a 1,000 year period
following disposal facility closure. The composite analysis results shall be used
for planning, radiation protection activities, and future use commitments to minimize
the likelihood that current low-level waste disposal activities will result in the
need for future corrective or remedial actions to adequately protect the public
and the environment.
(4) Performance Assessment and Composite Analysis Maintenance. The performance assessment
and composite analysis shall be maintained to evaluate changes that could affect
the performance, design, and operating bases for the facility. Performance assessment
and composite analysis maintenance shall include the conduct of research, field
studies, and monitoring needed to address uncertainties or gaps in existing data.
The performance assessment shall be updated to support the final facility closure.
Additional iterations of the performance assessment and composite analysis shall
be conducted as necessary during the post-closure period.
(a) Performance assessments and composite analyses shall be reviewed and revised
when changes in waste forms or containers, radionuclide inventories, facility design
and operations, closure concepts, or the improved understanding of the performance
of the waste disposal facility in combination with the features of the site on which
it is located alter the conclusions or the conceptual model(s) of the existing performance
assessment or composite analysis.
(b) A determination of the continued adequacy of the performance assessment and
composite analysis shall be made on an annual basis, and shall consider the results
of data collection and analysis from research, field studies, and monitoring.
(c) Annual summaries of low-level waste disposal operations shall be prepared with
respect to the conclusions and recommendations of the performance assessment and
composite analysis and a determination of the need to revise the performance assessment
or composite analysis.
(5) Disposal Authorization. A disposal authorization statement shall be obtained
prior to construction of a new low-level waste disposal facility. Field Elements
with existing low-level waste disposal facilities shall obtain a disposal authorization
statement in accordance with the schedule in the Complex-Wide Low-Level Waste Management
Program Plan. The disposal authorization statement shall be issued based on a review
of the facility's performance assessment, composite analysis, performance assessment
and composite analysis maintenance, preliminary closure plan, and preliminary monitoring
plan. The disposal authorization statement shall specify the limits and conditions
on construction, design, operations, and closure of the low-level waste facility
based on these reviews. A disposal authorization statement is a part of the radioactive
waste management basis for a disposal facility. Failure to obtain a disposal authorization
statement by the implementation date of this Order shall result in shutdown of the
disposal facility.
(6) Disposal Facility Operations. The disposal facility design and operation must
be consistent with the disposal facility closure plan and lead to disposal facility
closure that provides a reasonable expectation that performance objectives will
be met. Low-level waste shall be disposed in such a manner that achieves the performance
objectives stated in this Chapter, consistent with the disposal facility radiological
performance assessment. Additional requirements include:
(a) Operating procedures shall be developed and implemented for low-level waste
disposal facilities that protect the public, workers, and the environment; ensure
the security of the facility; minimize subsidence during and after waste emplacement;
achieve long-term stability and minimize the need for long-term active maintenance;
and meet the requirements of the closure/post-closure plan.
(b) Permanent identification markers for disposal excavations and monitoring wells
shall be emplaced.
(c) Low-level waste placement into disposal units shall minimize voids between waste
containers. Voids within disposal units shall be filled to the extent practical.
Uncontainerized bulk waste shall also be placed in a manner that minimizes voids
and subsidence.
(d) Operations are to be conducted so that active waste disposal operations will
not have an adverse effect on any other disposal units.
(e) Operations shall include a process for tracking and documenting low-level waste
placement in the facility by generator source.
(7) Alternate Requirements for Low-Level Waste Disposal Facility Design and Operation.
Requirements other than those set forth in this Section for the design and operation
of a low-level waste disposal facility may be approved on a specific basis if a
reasonable expectation is demonstrated that the disposal performance objectives
will be met.
Q. Closure. The following requirements are in addition to those in Chapter I of
this Manual.
(1) Disposal Facility Closure Plans. A preliminary closure plan shall be developed
and submitted to Headquarters for review with the performance assessment and composite
analysis. The closure plan shall be updated following issuance of the disposal authorization
statement to incorporate conditions specified in the disposal authorization statement.
Closure plans shall:
(a) Be updated as required during the operational life of the facility.
(b) Include a description of how the disposal facility will be closed to achieve
long-term stability and minimize the need for active maintenance following closure
and to ensure compliance with the requirements of DOE 5400.5, Radiation Protection
of the Public and the Environment.
(c) Include the total expected inventory of wastes to be disposed of at the facility
over the operational life of the facility.
(2) Disposal Facility Closure. Closure of a disposal facility shall occur within
a five-year period after it is filled to capacity, or after the facility is otherwise
determined to be no longer needed.
(a) Prior to facility closure, the final inventory of the low-level waste disposed
in the facility shall be prepared and incorporated in the performance assessment
and composite analysis which shall be updated to support the closure of the facility.
(b) A final closure plan shall be prepared based on the final inventory of waste
disposed in the facility, the plan implemented, and the updated performance assessment
and composite analysis prepared in support of the facility closure.
(c) Institutional control measures shall be integrated into land use and stewardship
plans and programs, and shall continue until the facility can be released pursuant
to DOE 5400.5, Radiation Protection of the Public and the Environment.
(d) The location and use of the facility shall be filed with the local authorities
responsible for land use and zoning.
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