Rule2025-15741
Approval of Replacement Waste Panels 11 and 12 at the Waste Isolation Pilot Plant
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
August 19, 2025
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA, or the Agency) has approved the U.S. Department of Energy's (DOE, or the Department) planned change request to dispose of defense transuranic (TRU) waste in replacement panels 11 and 12 in the Waste Isolation Pilot Plant (WIPP). This decision is based on a thorough review of information submitted by DOE, independent technical analyses, and public comments. EPA found that DOE demonstrated that the use of two replacement waste panels to replace lost waste disposal volume in panels 1, 7, and 9, would provide a reasonable expectation of the WIPP remaining in compliance with the 10,000-year release limits set by the "Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes" at 40 CFR part 191.
Full Text
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<title>Federal Register, Volume 90 Issue 158 (Tuesday, August 19, 2025)</title>
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[Federal Register Volume 90, Number 158 (Tuesday, August 19, 2025)]
[Rules and Regulations]
[Pages 40236-40241]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-15741]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 194
[EPA-HQ-OAR-2024-0309, FRL 12855-01-OAR]
Approval of Replacement Waste Panels 11 and 12 at the Waste
Isolation Pilot Plant
AGENCY: Environmental Protection Agency.
ACTION: Notification of approval.
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SUMMARY: The U.S. Environmental Protection Agency (EPA, or the Agency)
has approved the U.S. Department of Energy's (DOE, or the Department)
planned change request to dispose of defense transuranic (TRU) waste in
replacement panels 11 and 12 in the Waste Isolation Pilot Plant (WIPP).
This decision is based on a thorough review of information submitted by
DOE, independent technical analyses, and public comments. EPA found
that DOE demonstrated that the use of two replacement waste panels to
replace lost waste disposal volume in panels 1, 7, and 9, would provide
a reasonable expectation of the WIPP remaining in compliance with the
10,000-year release limits set by the ``Environmental Standards for the
Management and Disposal of Spent Nuclear Fuel, High-Level and
Transuranic Radioactive Wastes'' at 40 CFR part 191.
DATES: This decision is effective immediately.
ADDRESSES: Docket: All documents in the docket are listed in the
<a href="http://www.regulations.gov">www.regulations.gov</a> index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
EPA has established a docket for this action under docket ID No. [EPA-
HQ-OAR-2024-0309]. Publicly available docket materials related to this
action (e.g., EPA review documents) are available either electronically
through <a href="http://www.regulations.gov">www.regulations.gov</a>, on the Agency's WIPP website (<a href="http://www.epa.gov/radiation/wipp">http://www.epa.gov/radiation/wipp</a>) or in hard copy at the Air and Radiation
Docket in EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301
Constitution Ave. NW, Washington, DC 20004. EPA Docket Center Public
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is (202) 566-1744 and the telephone number for the Air
[[Page 40237]]
and Radiation Docket is (202) 566-1742. In accordance with EPA's
regulations at 40 CFR part 2 and in accordance with normal EPA docket
procedures, if copies of any docket materials are requested, a
reasonable fee may be charged for photocopying.
FOR FURTHER INFORMATION CONTACT: Joseph Rustick, Radiation Protection
Division, Mail Code 6608T, U.S. Environmental Protection Agency, 1200
Pennsylvania Avenue NW, Washington, DC 20460; telephone number: 202-
343-9682; email address: <a href="/cdn-cgi/l/email-protection#691b1c1a1d000a024703061a0c1901290c1908470e061f"><span class="__cf_email__" data-cfemail="96e4e3e5e2fff5fdb8fcf9e5f3e6fed6f3e6f7b8f1f9e0">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. What is the WIPP?
II. Contents of the Planned Change Request
III. What did EPA review?
A. EPA Review Process
B. APPA Peer Review
C. 19 Panel PA
D. 12 Panel PA
IV. Public Comments and Responses
A. Question of PCR Significance
B. The Inclusion of Surplus Pu
C. Legacy Wastes
D. Site Characterization Data
E. Panels 13-19 and Related Issues
F. Fracking and Earthquakes
V. Determination
Preamble Acronyms and Abbreviations
Several acronyms and terms used to describe components of the WIPP
disposal system and performance assessment computer models are included
in this preamble. To ease the reading of this preamble and for
reference purposes, the following terms are defined here:
APPA Additional Panels Performance Assessment
CBFO U.S. Department of Energy Carlsbad Field Office
CCA Compliance Certification Application
CFR Code of Federal Regulations
CRA Compliance Recertification Application
DOE U.S. Department of Energy
EPA U.S. Environmental Protection Agency
LWA Land Withdrawal Act
NMED New Mexico Environment Department
PA Performance Assessment
PCR Planned Change Request
Pu Plutonium
RPPCR Replacement Panels Planned Change Request
TRU Transuranic
VOR Volume of Record
WIPP Waste Isolation Pilot Plant
I. What is the WIPP?
The Waste Isolation Pilot Plant (WIPP) is a transuranic (TRU)
radioactive waste disposal system developed by the U.S. Department of
Energy (DOE) that is located near Carlsbad in southeastern New Mexico.
TRU radioactive waste is emplaced about 650 meters (2,150 feet)
underground in an ancient layer of salt that will eventually ``creep,''
encapsulate, and isolate the waste from the surrounding environment.
The 1992 WIPP Land Withdrawal Act (Pub. L. 102-579) (LWA) limits
radioactive waste disposal in the WIPP to TRU radioactive wastes
generated by defense-related activities. The WIPP LWA provides EPA with
authority to oversee and certify the long-term performance of the WIPP.
The WIPP must meet EPA's generic radioactive waste disposal standards
at 40 CFR part 191, subparts B and C. These standards limit releases of
radioactive materials from disposal systems for radioactive waste and
require implementation of measures to provide confidence for compliance
with the radionuclide release limits. Additionally, the regulations
limit radiation doses to members of the public and protect groundwater
resources by establishing maximum concentrations for radionuclides in
groundwater.
In 1996, the Agency issued the WIPP Compliance Certification
Criteria, which are located at 40 CFR part 194, as mandated by the WIPP
LWA, section 8(c). DOE submitted the initial WIPP Compliance
Certification Application (CCA) in 1996. The Agency then issued a
conditional certification decision on May 18, 1998, determining that
the WIPP met the standards for radioactive waste disposal, but
identified four conditions as part of the approval (63 FR 27354). Since
the 1998 certification decision, EPA has conducted ongoing independent
technical reviews, recertifications, and inspections of all WIPP
activities related to compliance with the Agency's disposal
regulations. The WIPP has been recertified four times since the initial
certification in 1998, with the most recent recertification decision
occurring in 2022.
As part of the original design of the WIPP repository in the
initial CCA, the underground waste disposal region at the WIPP is
divided into ten panels. A panel is a group of rooms mined into the
salt, connected by tunnels called drifts. EPA's initial certification
of the WIPP and its most recent recertification of the WIPP in 2022
were both based on a planned footprint of ten waste panels (87 FR
26126, May 3, 2022).
II. Contents of the Planned Change Request
On March 14, 2024, EPA received a planned change request (PCR) from
DOE per 40 CFR 194.4(b)(3) seeking the Agency's approval to add two
replacement waste panels west of the current repository. These two
panels, 11 and 12, will be constructed to recover waste disposal volume
lost in panels 7 and 9 due to a 2014 radiological release that
contaminated the south end of the repository. Additionally, panel 1 was
not completely filled due to ground control issues arising from being
kept open so long before waste was emplaced. DOE calculated that 1.7
panels of waste volume will be needed to replace this lost volume,
rounded up to two panels for construction. DOE also stated that with
the addition of the two replacement panels, the WIPP will not exceed
the LWA waste disposal volume limit. DOE recently recalculated the
volume of waste already emplaced at WIPP by subtracting waste packages
and void space from the total volume of waste. With this updated waste
volume calculation, referred to as the Volume of Record (VOR), DOE
would need to mine additional waste panels to fully accommodate the
total authorized waste volume in the LWA. In the March 2024 PCR, DOE
used the VOR approach in its analyses to support the new panels. It did
not use the VOR approach in the 2019 Compliance Recertification
Application (CRA-2019) but DOE notified EPA of its intent to begin
using the VOR approach in 2018 and EPA subsequently concluded that the
VOR approach should have no effect on DOE's compliance with EPA's
regulations in WIPP Performance Assessment (PA) and the only
consequence is to increase the total repository volume required for
waste disposal at the WIPP beyond the original ten waste panels. EPA's
technical review on the VOR can be accessed under docket ID EPA-HQ-OAR-
2001-0012-0772.
The PCR, which DOE refers to as the Replacement Panels Planned
Change Request or RPPCR, contains a PA that DOE conducted to support a
demonstration that the repository will continue to meet the numeric
release limits in EPA's disposal regulations for the WIPP. As part of
the performance assessment, DOE calculated releases based on a
repository design of 19 panels, which DOE anticipates will be the
ultimate WIPP repository configuration at the time of closure. However,
with this PCR, DOE is only seeking EPA's approval of two replacement
panels and provided documentation to address the two replacement panels
within the context of the 19-panel design. This notice only addresses
the Agency's approval of panels 11 and 12. DOE would need to
[[Page 40238]]
submit a separate planned change request for any additional panels
beyond replacement panels 11 and 12.
The Agency evaluated DOE's 19-Panel RPPCR PA and supplementary
information submitted by DOE in response to information requests from
EPA (see Section III for greater detail). After reviewing DOE's
responses, EPA requested a PA using a 12-panel configuration to
supplement the information already provided (docket ID EPA-HQ-OAR-2024-
0309-0053). On February 20, 2025, DOE submitted the requested 12-panel
analysis (docket ID EPA-HQ-OAR-2024-0309-0049), which includes the
original ten panels and the two proposed replacement panels, to EPA,
labeling it a sensitivity study.
III. What did EPA review?
A. EPA Review Process
As a part of ongoing operations at the WIPP, DOE makes periodic
changes to aspects of the design and operation of the facility. Under
40 CFR 194.4(b)(3), DOE must report any planned changes in activities
or conditions that differ significantly from the most recent compliance
application. A PA to evaluate the impacts on long-term performance of
the repository may be included with these PCRs. PCRs and accompanying
documentation are reviewed by EPA to confirm the WIPP is expected to
continue to perform as predicted and that the basis for the most recent
compliance certification remains valid. EPA assesses whether the
planned change will invalidate the terms of the certification or
determination in evaluating whether approval should be given. 61 FR
5224, 5233, Feb. 9, 1996.
The goal of the Agency's technical review of the RPPCR was to
determine whether, with the new design, the WIPP adequately
demonstrates compliance with the requirements of 40 CFR part 194 and
the release limits of 40 CFR part 191, subparts B and C. EPA conducted
an extended review of the RPPCR because, if approved, it would increase
the repository footprint and it presented new issues in EPA's
experience of reviewing DOE planned changes. In addition, stakeholders
demonstrated intense interest in DOE's activities related to the
replacement panels. The process EPA applied to support review for DOE's
PCR entailed (1) a review of all materials submitted by DOE, (2)
requests for additional information from DOE, (3) solicitation of
public comment, and (4) independent performance of additional
confirmatory calculations by the Agency. This process is fully
documented in EPA's review document, ``EPA Review of DOE Replacement
Panels Planned Change Request, Part 1: Review of DOE 12-Panel
Sensitivity Study'' (docket ID EPA-HQ-OAR-2024-0309-0059) and discussed
in the following sections.
B. Additional Panels Performance Assessment (APPA) Peer Review
In 2021, DOE carried out a peer review to assess changes in the
conceptual WIPP performance model, focusing on new off-axis waste
panels added to the existing WIPP repository footprint. The current
WIPP repository consists of ten panels. Four panels are situated on
each side of the main north-south access drifts, with Panels 1-4
located on the east side and Panels 5-8 on the west side. The main
access drifts are further divided into Panel 9, positioned between
Panels 3-4 and Panels 5-6, and Panel 10, located between Panels 1-2 and
Panels 7-8.
The new ``off-axis'' waste panels, including Replacement Panels 11
and 12, and projected for any additional potential future panels, will
be connected to the existing repository via east-west main drifts that
link to the north end of the current north-south main access drifts
(see docket ID EPA-HQ-OAR-2024-0309-0007 for diagrams of the waste
panels). With the addition of these panels, the WIPP repository waste
area will no longer maintain a geometrically symmetrical layout.
To address this change in the future WIPP PAs, DOE selected and
developed three conceptual model changes: Disposal System Geometry,
Repository Fluid Flow, and Direct Brine Release, which were
subsequently evaluated through an independent peer review process. The
peer panel concluded that the APPA model was reasonable and aligned
with previous PA approaches, as long as it was assumed there would be
no significant variations in the waste inventory or material properties
of the halite in the off-axis panels.
EPA observed the peer review and published its evaluation in 2023
under docket ID EPA-HQ-OAR-2001-0012-0774. EPA deemed the peer panel's
conclusion reasonable and suitable for the off-axis repository
extension, finding that the application of the methodology to potential
new panels positioned outside the main axis or central alignment of the
existing repository serves as an illustrative example. Consequently,
the Agency considers the methodology accepted by the peer panel
appropriate for use in the 12-panel PA for this PCR, specifically
regarding the off-axis repository extension involving panels 11 and 12.
C. 19 Panel PA
As mentioned previously, the Agency evaluated DOE's 19-Panel RPPCR
PA and prepared comments and questions for further clarity. Seven sets
of questions were sent to DOE, and these can be found in the public
docket corresponding to the RPPCR. EPA received eight sets of responses
from DOE. Based on the Agency's review, including these responses, EPA
concluded that the 19-Panel PA provided by DOE lacked sufficient
information specific to the two replacement panels to support a
decision on the Department's RPPCR and therefore the Agency requested a
12-panel analysis (docket ID EPA-HQ-OAR-2024-0309-0053).
EPA's review of the 19-panel RPPCR PA will be documented
separately, primarily to provide feedback to DOE on changes needed in
future PAs to accommodate potential increases in the size of the WIPP
repository. EPA is not currently making a determination on the overall
adequacy of a 19-panel repository, nor is it approving DOE's 19-panel
RPPCR PA or its comparison with disposal standards.
D. 12 Panel PA
At EPA's request, DOE performed a 12-panel sensitivity study to
demonstrate the long-term performance of a 12-panel repository, which
is the anticipated configuration for this PCR. DOE conducted the
sensitivity study, CRA19_12P, using the waste inventory from DOE's most
recent compliance application, the 2019 Compliance Recertification
Application (CRA-2019), while considering the effects of a larger
repository waste disposal volume and footprint. In contrast to the 19-
Panel RPPCR PA, DOE did not use the VOR approach described in Section
II for the CRA19_12P analysis because it was based on the CRA-2019
inventory. The 19-Panel RPPCR PA used waste inventory estimates derived
subsequent to CRA-2019.
EPA evaluated updates made by DOE to the CRA-2019 PA database for
the CRA19_12P sensitivity study and observed that most of DOE's updates
were associated with the increased repository footprint and volume, but
updates were also made in the computer codes used to perform the study.
As with the result of the CRA-2019 PA, the total mean normalized
releases from the 12-panel sensitivity study (CRA19_12P) were below EPA
release limits.
EPA agrees with DOE's conclusion that the differences between the
results for the CRA-2019 PA and the CRA19_12P sensitivity study are
minor. This is
[[Page 40239]]
because the two calculations use similar input parameters. Also, the
increases in drilling penetrations from the larger repository footprint
are offset by decreases in waste concentration from the larger
repository volume.
EPA conducted its own sensitivity study, similar to its CRA19_COMB
analysis performed to support its 2022 recertification decision,
focusing on outstanding concerns from CRA-2019, such as drilling rates,
borehole plugging frequency, actinide solubility, and colloids (87 FR
26126). EPA identified several concerns with the CRA19_12P analysis,
all of which were addressed in the Agency's own sensitivity analysis. A
detailed discussion of these issues and the sensitivity calculations is
available in the Agency's review report of DOE's 12-Panel Sensitivity
Study (docket ID EPA-HQ-OAR-2024-0309-0059). EPA's calculations
considered: (1) an inconsistency in the CRA19_12P analysis, where an
increase in repository volume was noted, yet the reduced iron surface
area concentration--affected by the repository volume in the WIPP PA--
was overlooked; (2) updates to borehole drilling rates and plugging
frequencies that had received EPA authorization but were excluded from
the CRA19_12P study; and (3) EPA's historical geochemical concerns
regarding actinide solubilities, colloid properties, and oxidation
state assumptions used in DOE's CRA-2019 PA, which carried over into
the CRA19_12P study. The mean normalized releases calculated by EPA for
its sensitivity analysis, including the upper 95 percent confidence
limit, remained below the regulatory thresholds under 40 CFR 191.13.
With the information submitted by DOE and EPA's own calculations, the
Agency concludes that there is a reasonable expectation that the 12-
panel WIPP disposal system will comply with the regulatory standards.
IV. Public Comments and Responses
EPA held an informal, virtual public meeting on Thursday, December
7th, 2023, to provide information and provide an early preview of the
PCR prior to DOE's formal submission. EPA and DOE used this opportunity
to gather preliminary questions/comments/feedback from the public.
On July 16, 2024, EPA published a notice in the Federal Register
seeking public comment on the PCR. EPA then held a series of
stakeholder meetings in New Mexico (Carlsbad and Santa Fe) during the
week of August 26, 2024, to meet with the public and discuss DOE's PCR.
The purpose of these meetings was to gather comments from members of
the public on the PCR and to provide a facilitated forum for clarifying
questions. Staff from DOE and the New Mexico Environment Department
(NMED) were also in attendance. Material presented at these meetings
and video recordings have been uploaded to EPA WIPP website.\1\
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\1\ <a href="https://www.epa.gov/radiation/wipp-news">https://www.epa.gov/radiation/wipp-news</a>.
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EPA's initial review of the PCR was based on the 19-panel RPPCR PA
submitted by DOE in February 2024. This PA was discussed at the public
meetings in New Mexico in August 2024, and most of the written public
comments were also based on this PA. After the Agency requested the 12-
panel PA calculations on November 26, 2024, the public comment period
was extended to June 2, 2025, to capture additional public comments on
the updated PA. As mentioned in Section III, while EPA has reviewed all
of the public comments on the RPPCR, only those relevant to the later
12-panel PA were considered within the scope of this PCR decision.
Comments that pertain solely to the 19-panel RPPCR PA will be
considered outside the scope of this decision but will be retained by
EPA and addressed in a subsequent report relevant to future actions
taken by DOE.
The Agency received 33 written comments via the public docket, and
one comment received outside of the docket that the Agency committed to
addressing. The comments submitted to the docket were a mix of unique
comments as well as written versions of verbal comments delivered at
the public meetings. All verbal comments were captured by written
comments. EPA has reviewed all comments and prepared a separate
response to comments document, which is available in the public docket
(docket ID EPA-HQ-OAR-2024-0309-0058). More detailed responses can be
found in that document. Several of the more prominent issues raised are
summarized below.
A. Question of PCR Significance and Whether the Decision Requires a
Rulemaking
Many commenters expressed the view that EPA's review process for
the RPPCR must take place through a notice-and-comment rulemaking
because the addition of two replacement panels, coupled with other
changes to repository operations and the performance assessment,
``depart significantly from the previous compliance application.'' In
addition to individual comment submittals and statements at public
meetings, a number of interested organizations jointly sent letters
directly to EPA outlining the reasons for this position. The relevant
provision is located in 40 CFR 194.65(a):
If the Administrator determines that any changes in activities
or conditions pertaining to the disposal system depart significantly
from the most recent compliance application, the Agency will publish
a Notice of Proposed Rulemaking in the Federal Register announcing
the Administrator's proposed decision on modification or revocation,
and soliciting comments on the proposal.
The Agency disagrees that a rulemaking is necessary for this
decision. The Administrator has discretion in reaching a determination
regarding whether the changes described in the RPPCR ``depart
significantly from the previous compliance application.'' After careful
consideration, the Agency declines to determine that the RPPCR
represents a significant departure from the previous compliance
application (the 2019 Compliance Recertification Application or CRA-
2019), for the following reasons:
<bullet> The two replacement panels are primarily intended to
replace disposal capacity lost to the 2014 radiation release incident,
which prevented the full use of Panel 7 and the planned use of Panel 9,
as well as capacity in Panel 1 that was not utilized in the early phase
of emplacement as a result of ground control issues stemming from
scheduling of shipments, and therefore the new configuration represents
a disposal capacity comparable to that analyzed for the CRA-2019;
<bullet> The two replacement panels are of a similar size and
design to the existing eight panels described in the CRA-2019;
<bullet> A 1987 Time-Domain Electromagnetic (TDEM) geophysical
survey of the WIPP site provided estimates of the depths of brine
reservoirs that may be present beneath the ten original WIPP waste
panels. DOE reexamined the existing TDEM data and found that it also
adequately covers the area of replacement Panels 11 and 12. Therefore,
no new data needs to be collected for these two replacement panels. DOE
modeled the probability that a borehole may encounter a pressurized
brine pocket in the RPPCR as being the same as in CRA-2019. Upon
reviewing these data, EPA accepted DOE's conclusion that the current
site characterization data already covers the repository footprint,
including panels 1-10 and 11-12, and agreed with DOE not to change the
probability of encountering a pressurized brine pocket in the RPPCR;
<bullet> The types of waste that will be emplaced in the
replacement panels are expected to be similar to those analyzed for the
CRA-2019. A stated public
[[Page 40240]]
concern is the amount of surplus plutonium waste that gets disposed in
the two replacement panels. While a limited amount of down-blended
surplus plutonium is being emplaced in the repository, much of the
surplus plutonium designated for the ``dilute and dispose'' method, as
well as plutonium waste from potential new pit production, would need
to go in any additional future panels beyond the two panels currently
being requested by DOE;
<bullet> DOE's performance assessment for the 12-panel repository,
confirmed by EPA's independent sensitivity study, shows limited change
in releases and release paths from those described in the CRA-2019 and
the total mean release is under EPA regulatory limits;
<bullet> The New Mexico Environment Department approved the two
replacement panels in the site permit after an extensive review process
that included public comment.
Further, EPA has provided significant opportunity for public review
and comment, comparable to a rulemaking process. All submittals by DOE,
including responses to questions from EPA, have been posted in the
regulatory docket and on EPA's WIPP website. The comment period was
kept open more than 9 months to ensure the public's ability to review
all the relevant documentation, and a response to comments document has
been prepared to show how comments were considered, as would be done
for rulemaking.
B. The Inclusion of Surplus Pu
A number of commenters expressed concern for or opposition to DOE/
NNSA proposal to include surplus Pu waste streams in the inventory for
the new panels. They raised objections, questioning whether surplus Pu
would be eligible for disposal at WIPP under the LWA and whether
criticality or other issues had been properly addressed.
As noted in Section IV.A, the inventory and proportion of plutonium
wastes in the 12-panel repository is expected to be more aligned with
the previous CRA-2019, incorporating only limited amounts of surplus
plutonium. The majority of surplus plutonium, along with any pit
production wastes, would be destined for future waste panels for which
DOE would have to submit a separate PCR. The WIPP Land Withdrawal Act
(LWA) allows for disposal of 6.2 million cubic feet of defense related
TRU waste, which is defined in Section 2.(18) of the statute. DOE
establishes specific waste acceptance criteria (WAC) for the facility.
Wastes that do not meet the WAC are not allowed to be disposed of at
WIPP. The surplus Pu intended for disposal in the replacement waste
panels has been determined by DOE to be defense transuranic waste. EPA
has conducted multiple inspections of the down-blended waste
characterization process and will continue to do so. EPA has found
DOE's waste characterization system of controls for the down-blended
plutonium to be adequate. Similar forms of Pu in smaller amounts have
already been emplaced at WIPP in the existing waste panels.
C. Legacy Wastes
Several commenters mentioned the concept of legacy TRU wastes, and
that WIPP was only approved and authorized for the disposal of legacy
TRU wastes. Some commentators define legacy TRU as wastes produced
during the Manhattan project and through the end of the Cold War, while
other have defined legacy TRU as wastes before the opening of WIPP in
1999. All of the commenters on legacy TRU want EPA to establish a
definition of legacy TRU. Several commenters also requested that EPA
include provisions in its PCR approval for the prioritized emplacement
of legacy TRU wastes before newer generated wastes are disposed of.
The WIPP LWA and EPA's regulations do not explicitly use or define
``legacy TRU waste.'' Depending on the progress and status of waste
cleanup and waste generating activities, different waste generator
sites (e.g., National Labs) use and define the term ``legacy TRU
waste'' in slightly different ways. A recent report called ``Legacy TRU
Waste Disposal Plan'' from DOE's Carlsbad Field Office, dated November
2024 (<a href="https://wipp.energy.gov/Legacy-TRU-Waste-Disposal-Plan.asp">https://wipp.energy.gov/Legacy-TRU-Waste-Disposal-Plan.asp</a>),
submitted pursuant to a State of New Mexico permit condition, provides
more detail and documents activities and plans to continue to
prioritize the disposal of legacy wastes at WIPP. In a May 21, 2025,
letter commenting on this draft submittal, the State of New Mexico
requested that DOE exclude the surplus plutonium waste stream from
consideration as legacy waste.\2\
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\2\ <a href="https://hwbdocs.env.nm.gov/Waste%20Isolation%20Pilot%20Plant/250514.pdf">https://hwbdocs.env.nm.gov/Waste%20Isolation%20Pilot%20Plant/250514.pdf</a>.
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D. Site Characterization Data
One commenter mentioned that there is inadequate site
characterization data for the proposed panels 11 and 12, and that DOE
needs to do more site characterization to identify potential unknown
brine pockets.
As noted in Section IV.A, DOE determined that the original time
domain electromagnetic induction method (TDEM) survey that supported
the WIPP Compliance Certification Application and the original
repository footprint of Panels 1 through 10 also covered the area over
which the two replacement panels 11 and 12 are located. The TDEM survey
was used to determine the probability of encountering brine in the
underlying Castile Formation, which is then used to develop a parameter
(PBRINE) in WIPP PA. EPA closely scrutinized the data and derivation of
this parameter and found it suitable for the original repository
footprint. For the RPPCR, DOE utilized the existing TDEM data covering
the area of the replacement panels and prior established methods to
demonstrate that extending the PBRINE parameter used in PAs from
previous CRAs to the expanded 12 panel repository footprint was
conservative. EPA found this approach reasonable for the RPPCR.
E. Panels 13-19 and Related Issues
A number of commenters mention the inclusion of panels 13-19 in the
initial 19-panel RPPCR PA, which are not being requested at this time.
There are also a number of comments that address issues pertaining
solely to the 19-panel PA or to panels 13-19 and not panels 11-12.
With this PCR, DOE is only seeking EPA approval of the two
replacement panels. During EPA's review, the Agency identified that the
panels 13-19 were not directly pertinent to the decision on the
requested panels 11 and 12. EPA requested the separate 12-panel PA to
clarify the impacts of the two proposed replacement panels, and that
analysis is the basis for its approval of the RPPCR. EPA will address
potential future panels beyond panels 11-12 when and if DOE submits an
additional PCR. The Agency will produce a separate report on its review
of the 19-panel PA later in 2025.
F. Fracking and Earthquakes
Many stakeholders and members of the public have shared concerns
regarding risks to the WIPP from hydraulic fracturing (``fracking'')
and earthquakes. Earthquakes, including those related to oil and gas
operations, have been monitored for decades in the Permian Basin
region, and the risks to the WIPP have been evaluated and reevaluated
many times (see EPA's Technical Support Document Review of Features,
Events and Processes (FEPs) in the CRA-2019 docket, docket ID EPA-HQ-
OAR-2019-0534-0054). Data
[[Page 40241]]
continues to be collected, and the available information indicates that
earthquakes, whether human-caused or natural, are not capable of
generating enough shaking to impact operations at the WIPP, nor to
damage facilities or the radioactive waste buried there, even far into
the foreseeable future. EPA, DOE, and regulators in New Mexico and
Texas are aware of and have investigated this and related issues.
Additionally, when the land for the WIPP was set aside by Congress
by the LWA, surface drilling activities for resources and mining for
potash were prohibited inside the 4 x 4-mile square, and will not be
allowed into the foreseeable future, even after WIPP is closed. This
prohibition and the designated space serves as an institutional control
to protect the repository and is one element of many in the safety
design of the WIPP. There are no known, active faults that reach at the
ground surface within nearly 100 miles of the WIPP site, and the
northern part of the Delaware Basin where WIPP is located also has few
mapped faults in the deeper ``basement'' rocks. The general lack of
clear patterns in the seismicity also suggests relatively few faults.
V. Determination
After conducting a thorough review of information submitted by DOE,
independent technical analyses, and public comments, including DOE's
supporting documentation regarding its 12-panel sensitivity study, EPA
generally agrees with DOE's approach and interpretation of the PA
results. While EPA had concerns about several of DOE's input
parameters, these were alleviated by the results of EPA's independent
sensitivity analysis, which showed that the total mean normalized
releases remain below EPA's regulatory limits. As a result, the Agency
concluded that there is a reasonable expectation that the 12-panel
disposal system represented in DOE's Planned Change Request will comply
with the standards and requirements in 40 CFR parts 191 and 194. Thus,
EPA approved DOE's Planned Change Request to use replacement Panels 11
and 12 at the WIPP repository for the disposal of defense TRU
radioactive waste.
Abigale Tardif,
Principal Deputy Assistant Administrator, Office of Air and Radiation.
[FR Doc. 2025-15741 Filed 8-18-25; 8:45 am]
BILLING CODE 6560-50-P
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