The Waste Isolation Pilot Plant: A Potential Solution for
the Disposal of Transuranic Nuclear Waste

P. Thakur
Carlsbad Environmental Monitoring and Research Center
Carlsbad, NM 88220, USA

Jan 21, 2021

WIPP: A Working Repository• 15 years of safe operations andpermanent geological disposal oftransuranic defense wastes[Intermediate-Level Long-Lived
Waste by IAEA definition].
• Located in southeast New Mexico
about 26 miles east of Carlsbad.
• TRU waste is man maderadioactive elements that areheavier than uranium (Z>92).
• >100 nCi/g (>3700 Bq/g or~1ppm) alpha emitting
isotopes with t½ > 20 years.
• WIPP is also the first to recoverfrom an accident and resume
operations.

WIPP Layout
New Filter Building

Waste
Shaft

Air
Intake
Shaft

Exhaust
Shaft

Salt
Shaft

Current waste
emplacement: Panel 7

New
Shaft

Panel 8 mining

8

7

6

Quick Facts: As of DEC 2020
• Opened March 26, 1999
• 12,827 shipments received• 98,579 cubic meters of waste disposed
New
State University• 176,482 containers emplaced
inMexico
the underground

5

1

2

Filled waste
panels (Panels
1-6)
3
4

Equivalent
Panel 9pending
closureWIPP Regulatory Framework
Public Law 102-579, WIPP Land Withdrawal Act (LWA), 102nd Congress
Withdraw certain public lands and to otherwise provide for the operation of WIPP

U.S. Department of Energy (DOE)
Worker Safety, Industrial Safety, Nuclear Safety, Radiological Safety, Security

U.S. Environmental Protection Agency (EPA)
Repository certification, TRU Waste Activity, PCB/TRU waste, air, ground water

New Mexico Environment Department (NMED)RCRA hazardous constituents, air, water discharge, ground water

U.S. Nuclear Regulatory Commission (NRC)
Transportation Type B packages for nuclear materials

U.S. Department of Transportation (DOT)
Mexico State
HighwayNewtransportation,
TypeUniversity
A containers

Salt is the reason for WIPP’s location
National Academy of Sciences (NAS) concludes in 1957 that the mostpromising disposal option for all radioactive waste is in massive salt deposits“Salt at great depth ‘flows.’ It will
encapsulate any waste placed at
depth and isolate it from the surface
environment for eons.” – NAS“Salts are not all equal: Massiveinterbedded domed”“The great advantage is that no watercan pass through salt. Fractures are self
healing..” - NAS

Nuclear waste Classifications in the US
In the meantime…..

….disposal options for wastefrom power production versus
weapons production begins todiverge in the 1970’s
1970 - AEC establishes new category fortransuranic waste, distinct from low-level
radioactive waste.
1976 - Atwater convinces Ford/Carter to outlaw
reprocessing of commercial spent fuel;retrievable storage concept is born.

Contact Handled (CH)<200 mrem/hr
Remote Handled (RH)
>200 mrem/hr

TRU waste Properties Materials contaminated with manmade radioactive elements heavier
than uranium– Debris: clothing, tools, rags,
containers,
etc.
understanding of risk thatis endemicto– Soilsa multi-generational mining
town– Homogeneous solids, residues

 >100 nCi/g (>3700 Bq/g ~1ppm):– alpha emitting isotopes– t½ > 20 years

 Two types of TRU waste– Contact-handled (<2 m Sv/hr)– Remote-handled (>2 mSv/hr)

 Legacy inventory ~700,000 drum
equivalents

Z > 92 (transuranic)

U.S. Department of Energy TRU Waste Generator Sites

understanding of risk that is endemic toa multi-generational mining town

Large Quantity site
Small Quantity site
WIPP

Red = De-inventoried of all TRU waste
Yellow = Active Sites

AE Argonne National Laboratory
AL Ames Laboratory
AM ARCO Medical Products
AW Material and Fuels Complex
BC Battelle Columbus Laboratories
BL Babcock and Wilcox Nuclear Energy Services
BN Brookhaven National Laboratory
BT Bettis Atomic Power Laboratory
ET Energy Technology Engineering Center
FM Fernald Environmental Management Project
FR Framatome (AREVA) IN Idaho National
Laboratory
IT Inhalation Toxicology Research Institute
KA Knolls Atomic Power Laboratory
KN Knolls Atomic Power Laboratory-NFS
LA Los Alamos National Laboratory
LB Lawrence Berkeley Laboratory
LL Lawrence Livermore National Laboratory
MC U.S. Army Materiel Command MD Mound Plant
MU University of Missouri Research Reactor
ND Nuclear Radiation Development Site, Inc.
NT Nevada Test Site OR Oak Ridge National
Laboratory
PA Paducah Gaseous Diffusion Plant
PX Pantex Plant
RF Rocky Flats Environmental Technology Site
RL Hanford Site (Richland Operations Office)
RP Hanford Site (Office of River Protection)
SA Sandia National Laboratories
SP Separations Process Research Unit
SR Savannah River Site
TB Teledyne Brown Engineering
VN General Electric Vallecitos Nuclear Center
WV West Valley Demonstration Project
WP Waste Isolation Pilot Plant

Characterization
Process to determine the physical, chemical and radiological contents of TRU
waste containers to ensure that waste is acceptable for disposal at WIPP

Acceptable
Knowledge

Radiography

Nondestructive
assay

Statisticalheadspacegas analysis

Statisticalsolidssampling &analysis

Waste Stream

DetermineUse documented Look for
Determine
volatile organic
prohibited
waste stream
radiologicalcompounditems, such as contents
knowledge tocontents
aerosol cans or
identify waste
liquids
contents
understandingof risk that is endemic toa multi-generational mining town

Performed on
samples ofhomogeneous waste
to analyze forchemical hazards

Central Characterization Project(deploying mobile waste characterization systems to sites around the complex
Mobile systems perform waste characterization at sitesthat lack equipment, and to supplement sites with
their own facilities to keep ‘pipeline’ full

Systems
currentlyat:understandingof riskthat isdeployed
endemic to• SavannahRiver town
Site (SRS)a multi-generational
mining••••Idaho National Laboratory (INL)
Los Alamos National Laboratory (LANL)Oak Ridge National Laboratory (ORNL)
Argonne National Laboratory (ANL) – RH only

Mobile systems can characterize ~90-100 waste
packages/week (~3 shipments/week)
Throughput limited by the rate that host site can supply
compliant feed containers (highly dependent on
remediation of prohibited items, e.g., liquids)
Eliminates need to build costly fixed facilities, saving
taxpayers millions (cost still ~$2,500 per package)Transportation
Shipment tracked by satellite

understanding of risk that is endemic toa multi-generational mining town

Waste
containers areloaded into
protective
shipping
containers(such asTRUPACT-II)

Waste
containers areloaded into
protective
shipping
containers(such asTRUPACT-II)

Drivers inspect
their rigs andloads every 3
hours or 150
miles. Somestates require
additional
inspections attheir ports of entry

For safety andsecurity reasons,shipments aretrackedthroughout theirjourney using asatellite system(TRANSCOM)

WIPP-trained stateand local
emergency
responders(~30,000) along all
shipping routes,
with frequent
exercises

WIPP’s Shipping Containers

understanding of risk that is endemic toa multi-generational mining town
TRUPACT II

Half Pact

TRUPACT III

WIPP has a nationally recognized transportation safety program

RH 72BWIPP Transportation Routes

understanding of risk that is endemic toa multi-generational mining town

Highway Legend

Interstate Highway
U.S. Highway
Principal Highway

Every town and city along all
WIPP transportation routes
have been provided radiationand nuclear hazard response
training (Over 30,000 fire, policeand medical first responders

MgO backfill sack

WASTE EMPLACEMENT

Mining the Salado is theeasiest and safest mining
operation in the world –a soft rockRH waste

MgO backfill sackunderstanding of risk that is endemic toa multi-generational mining town

RH Waste Emplacement
The higher activity waste is remotely
handled in shielded transport casks

understanding of risk that is endemic toa multi-generational mining town

The higher activity waste is remotely plunged
into boreholes the room walls prior to fillingwith the lower activity waste

How salt encapsulates the Waste

understanding of risk that is endemic toa multi-generational mining town

understanding of risk that is endemic toa multi-generational mining town

understanding of risk that is endemic toa multi-generational mining town

WIPP experience (Video)After 20 Years WIPP’s merits and issues are still debatedunderstanding of risk that is endemic toa multi-generational mining town

The first transuranic waste shipment arrives at the Waste
Isolation Pilot Plant in the early morning of March 26,
1999.

WIPP Incidents

February 5, 2014 Underground Fire

February 14, 2014 Radiation Release

Drum fire
Panel 7, Room 7
2

Filtration bypass allowed some (minor) external
contamination
Station B

Station A• Two leaking dampers allowed some contamination to bypass thefiltration system

Underground Source Term Estimation• The total radiological inventory inthe drum was estimated to bearound 9 Ci.
• It is estimated that between 5%
and, at most, 20% of the drum
inventory released into the WIPP
underground.
• Source term estimation ~ 0.3-1.5
Ci of radioactivity released fromthe breached drum.
• The radiological constituents inthe drum include: 241Am, 243Am,
237Np, 238Pu, 239Pu, 240Pu, 241Pu, and242Pu (>95% of activity).
Data source: CEMRC, NWP and Hunter & Viner 2015

Consequence Assessment

Environmental Monitoring and WIPP Before site selection, DOE and local community leadersrecognized the value of independent oversight for maintaining
community support
 The purpose was to independently establish a baseline before
operations began, and then evaluate the radiological fingerprintof the facility in its environmental setting throughout its
operational lifetime.
 The Land Withdrawal Act (Public Law 104-201) establishedmonitoring through the Environmental Evaluation Group (EEG).
 The New Mexico Environment Department (NMED)- DOE
Oversight Bureau, established in 1989.
 The Carlsbad Environmental Monitoring and Research Center(CEMRC), established in 1991.
New Mexico State University

CEMRC’s -Independent Monitoring Program Overview
 Funded Primarily by the Department of Energy (DOE) through agrant (NOT a contract) that respects CEMRC independence Current funding level $3m per year (~80% of total funding
for CEMRC)
 CEMRC monitoring and other work includes:
 WIPP Underground Exhaust Air
 Ambient Air
 Drinking Water
 Soil and sediment Surface Water & Ground water Whole Body Counting for Area Residents age 13+
 R&D on monitoring methods and technologies
New Mexico State University

Role of Independent Environmental Monitoring CEMRC communicated all its monitoring results to the public throughpress releases and by posting on the CEMRC website www.cemrc.org
 Timely dissemination of independently measured and interpreted
environmental monitoring data following the release event, through local
newspaper and Town Hall type meetings, helped develop trust throughtransparency
 Public access to the monitoring data and their ability to directly
participate in CEMRC’s whole body counting program provided a sense of
security to concerned citizens after the event
 Develop relationships with the host community – local and online
 Establish trust before an incident – during the incident is too late
 CEMRC helped alleviate fear in the local community and restoredconfidence because it is independent
New Mexico State University
New Mexico State University

WIPP Underground Air Sampling Stations (A and B)

Station A,
before filtration

Station B, at postfiltration outlet

New Mexico State University

Current Radiation Levels in the WIPP Underground Air

1 DAC Pu-239

Unfiltered (Pre-HEPA)
Exhaust air

Filtered (Post HEPA) Exhaust air
10Source Term From Station A-Filter Analysis
Total Estimated Release of Radioactivity to Station A from the
WIPP underground

CEMRC analyses:• 180.1 mCi of 241Am and• 40.3 mCi of 239+240Pu

Total = ( ~228 mCi )NWP analyses :• 123.1 mCi of 241Am and• 39.1 mCi of 239+240Pu

Total = (~168 mCi).

Total Environmental Release
Total atmospheric Released
CEMRC analyses:••

0.72 mCi of 241Am and0.067 mCi of 239+240Pu

Total = ( ~1 mCi ).
NWP analyses :••1.21 mCi of 241Am and0.068 mCi of 239+240Pu

Total = (~1.3 mCi).

On Site and Off Site Radiation Levels
CEMRC Air sampling sites

Am-241

Pu-239+240• Onsite detection: 115 µBq/m3 of 241Am; 81.4 µBq/m3• No off-site hi-volume sampler detections were positively attributable to the WIPP release event.

Modeling the atmospheric dispersion plume14-15 February 2015 release wasmodeled based on measured filter
values and wind data in 15-minuteincrements• Inhalation doses constructed as if
all alpha was only 239Pu(conservative) and a hypotheticalhuman breathed for entire
duration of release.
• Inner darker green area >0.01 mSv• Outer green area ranged from 0.01
to 0.001 mSv.
• Stars indicate sampling stations.
• Modeling of deposition in bothgreen areas suggested none would
be detectable on soil or vegetation(proven correct).

16 sq miles boundary

Both predicted and measured values of ground contamination are below
detectable levels

Soil Location• All results to date were either below
Minimum Detectable Concentrations (MDCs)
or, for Pu, at levels seen prior to the event
Accumulated Deposition
During First 12 hours• Positive Pu detections did not havedetectable Am, suggesting a non-WIPP event
source, perhaps the nearby Gnome test’s
atmospheric release (1961)

Workers Exposer- Radio-bioassay
Fecal samples: 31
 21 low-level positive• 21 positive for 241Am• 7 positive for Pu
 0.024 Bq (1.45 dpm) was highest
total activity in a sample
Urine samples: 140 1 low-level 241Am positive
Dose to the Contaminated workers

 Between Feb-July, 2014, 144

WIPP workers and 42 local
citizens were counted.
 0.1 nCi MDA for 241Am
 241Am not detected.

WIPP Underground –Contamination Status
A water spray is being used
to remove and “fix”
contamination from walls
and ceilings (ribs andbacks).
When the salt recrystallizes,
it encapsulates thecontamination and prevents
any resuspension ofradioactive.
In some areas, Brattice clothand a layer of
uncontaminated salt on topof the cloth are used tofurther trap any
contamination on the floor.

Plutonium Ambient Air Concentrations in the US

WIPP underground is a radiation-deprived environment

WIPP radiation levels average• 0.031 µSv/h at the surface,• 0.006 µSv/h 655m
underground or 2.2µSv/year

Source: G.B. Smith, et al., Health Physics,100: 263-265 (2011).
New Mexico State University

Why Are We So Afraid of Nuclear ?
 Radiation and the risk associated with
it -is the sole reason why people fear
and nuclear energy.
 General public often associates
nuclear energy with radiation andradiation with cancer.
 Natural radiations are less scary- butradiation from nuclear facilities are
dangerous.
 Just because we can measure radiation
does not necessarily mean that it isdangerous.
 We live in a world that is full of naturalradiation-yet our species thrives.
Therefore we must have developed amechanism to cope with the biologicaleffects of radiation.
New Mexico State University

FEAR OF RADIATION: The Problem as it Stands TodayNMSU Low Background Radiation Experiments

 The fear of radiation originated around 1959,
when the world adopted a hypothesis called
the Linear No-Threshold (LNT).
 The LNT assumes that there is no amount ofradiation is safe, even the earth’s
background.
 Scientific data show health effects only athigh (>100 mSv) exposures
Leukemia incidence of 96,000 Hiroshima
atomic bomb survivors is compelling
evidence that the LNT model is wrong.
 LBRE is showing that the LNT does notconsider an organisms defense mechanisms,
and that they may have evolved to thrive inthe presence of non-zero backgroundradiation.
New Mexico State University

Underground Radiation and Risk
• The primary risk from occupational radiation
exposure is an increased risk of cancer.
• The amount of risk depends on the amount ofradiation dose received, and the body parts
exposed.
• Although scientists assume low-level
radiation exposure increases one’s risk ofcancer; medical studies have notdemonstrated adverse health effects inindividual exposed to small chronic radiation
doses (up to 10 rem above background).
• If a person received a radiation dose of 10
rem to the entire body (above background),his or her chance of getting cancer would
increase by 1%.

Estimated Cancer Risks to a
population of 10,000
New Mexico State University
New Mexico State University

WIPP radiation Release Event in numbers
Accident
Winscale
1957
Three mile
Island, 1979
Chernobyl,
1986
Fukushima,
2011
WIPP, 2014

Type
Reactor fire

Release ofRadioactive
materials

Populations
Evacuated

20,000 Ci, 131I
No evacuation
594 Ci 137Cs
0.02TBq Pu
Partial core
13-17 Ci 131I
Voluntary short term
melt
34,000 Ci 85Kr evacuation of nearby
communities due tomisinformation.
1.4E+8 Ci
28, deaths,
Runaway>300, 000 relocatedfission process
destroying thereactorThree reactor
1.2E+7 Ci~160, 000 evacuatedunits severelywith prospects ofdamagedreturn still unclear
after 6 six years
Waste Drum
0.0013 Ci
No evacuation
breachNew Mexico State University

Off-sitedose
10 timethe Bkgd
level
0.08-1.0
mSv

Estimated cleanup costs inmillion US$
70,000Complete by 2037
~1000
12 years>20 mSv

250,000-500,000~10 mSv

100,000-500,000

1-10
µSv

500

Conclusions and Recommendations• The WIPP radioactive release event was serious:• It stopped operations for almost three years• It cost up to a half billion dollars to recover the facility• The WIPP radiation release event was minor:• In terms of exposures to workers (no doses assigned based on low and temporary
bioassay results) and environmental contamination• There are no public health implications given such low off-site releases• The WIPP Underground air is relatively clean :• The residual radioactivity levels in the underground no longer warrant HEPA filtrationin order to meet either worker or environmental protection criteria• DOE should consider resumption of the unfiltered discharge of undergroundventilation• Independent voice and communication extremely important• With public and elected officials and also internally• Between site developer and regulator• Transparency; don't withhold information•

Be Prepared• Plan for a release, be able to measure it and mitigate it
Mexico State
University• Be able to tell public whatNew
the potential
impactis-quickly and on a sustainable basis

Acknowledgement
CEMRC- Research is supported by the Waste Isolation Pilot Plant,
Department of Energy, Carlsbad Field Office (CBFO)
through a grant DE-FG29-91AL7416.

New Mexico State University
New Mexico State University