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Material Disposal Areas

David S. RhodesAcquisition Integrated Project Team Chair

Environmental Management Los Alamos Field Office

March 3, 2015

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Material Disposal AreasMaterial Disposal Areas MDA-A at TA-21

• Complete a removal action of two 50,000 gallon plutonium solution (General’s) Tanks with sludge heelso The removal action could be relatively near-term (3-4 years)

• Complete investigation and evaluate alternatives of central debris pit and waste trenches, support NMED development of a Statement of Basis for a remedy

• Execute the remedy which is planned as (but not determined) an engineered cover including material procurement and construction

MDA-C • Support NMED development of a Statement of Basis for a remedy• Execute the remedy which is planned as (but not determined) an engineered cover

including material procurement and constructiono This might be appropriate for a near-term capital asset project

MDAs-G, -H, and L at TA-54 • Support NMED development of a Statement of Basis for each of three potential remedies• Execute the remedy which are planned as (but not determined) engineered covers

including material procurement and construction and possibly includes Soil-Vapor Extraction (SVE) for Areas L and G

• Highly dependent on Transuranic (TRU) Waste completion schedules

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Material Disposal AreasMaterial Disposal Areas

MDA-T at TA-21• Complete investigation and evaluate alternatives of central debris pit and waste

trenches, support NMED development of a Statement of Basis for a remedy• Execute the remedy which is planned as (but not determined) an engineered

cover including material procurement and construction• Expected to remain under Federal control indefinitely

MDA-AB at TA-49• Complete investigation and evaluate alternatives of central debris pit and waste

trenches, support NMED development of a Statement of Basis for a remedy• Execute the remedy which is planned as (but not determined to be) an

engineered cover including material procurement and construction

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MDA-B History

Waste disposal site consisting of a series of shallow disposal trenches for hazardous and radioactive wastes• Approximately 6 acre site operated from 1944-1948

2010 CD-2 baseline • $110.5M Total Project Cost• Completion September 30, 2012• Estimated at 22,000 cubic yards• Thought to be shovel-ready for American Recovery and Reinvestment Act

(ARRA) project – minimally characterized

Actual completion performance• $131.2M total project costs• Completed March 31, 2013• 47,000 cubic yards from trench depths twice what expected

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MDA-A at TA-21

Two buried General’s Tanks• 50,000 gallon plutonium solution recovery• No known releases from tanks• Coffer dams installed for access• Sampled and Light Detection And Ranging (LIDAR) surveyed heels• Expected to be TRU waste

Central construction debris pit• Potentially radiologically contaminated

Two disposal trenches• Operated same timeframe as MDA-B trenches• Expect similar disposal practices (end of trenches with more content)

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MDA-A Aerial View

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MDA-A

Remedy expected to be driven by radiological contaminants• DOE likely regulatory decision-making authority• Some hazardous constituents expected with NMED regulatory authority• Still missing information for evaluating alternatives

Requested NMED allow completion of characterization• NMED decision on characterization pending

Next steps• DOE-directed General’s Tanks Removal Action• Phase II investigation work plan and field sampling activities for pit and

trenches• Phase II Investigation Report• Corrective measures evaluation to considered excavation of engineered cover• NMED Statement of Basis • Remedy implementation

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MDA-C

Site background and operational history• 11 acre site• Borders NNSA operational facilities• Fenced and graded with stabilizing cover plants

Vadose zone VOC plume• Pore gas monitoring• Impacts on adjacent new projects for construction worker scenario

LANL recommended alternative• SVE• Evapo-transpiritive (ET) cap with bio-intrusion barrier and native vegetation• Long-term monitoring and maintenance

NMED review of Corrective Measures Evaluation and Draft Statement of Basis pending

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MDA-C layout

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MDA-C vapor plume

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MDA-L remedy project

Site background and operational history• 2.5 acre TA-54 site, located adjacent to Pueblo de San Ildefonso• Used from 1959 to 1985• Subsurface pit / impoundments / shafts used for disposal of chemical wastes

CME overview• CME revised and submitted to NMED September 2011• CME addresses hazardous constituents in units, and VOC vapors in vadose

zone• Alternatives considered – no action, and combinations of capping, excavation

and SVE

LANL recommended alternative• SVE• Evapo-transpiritive (ET) cap with bio-intrusion barrier and native vegetation• Long-term monitoring and maintenance

NMED review of Corrective Measures Evaluation and Draft Statement of Basis pending

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MDA-L Facilities

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MDA-H remedy project

Site background and operational history• 0.3 acre TA-54 site, located adjacent to Pueblo de San Ildefonso• Used from 1960 to 1986• Subsurface shafts used for disposal of classified solid wastes

CME overview• CME revised and submitted to NMED September 2011• CME addresses hazardous constituents in units• Alternatives considered – no action and combinations of capping and excavation

LANL recommended alternative• Evapo-transpiritive (ET) cap with bio-intrusion barrier and native vegetation• Long-term monitoring and maintenance

NMED review of Corrective Measures Evaluation and Draft Statement of Basis pending

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MDA-G remedy project

Site background and operational history• Within 63-acre TA-54 site, located adjacent to Pueblo de San Ildefonso• Used since 1957, intermingled with active Area G LLW disposal units• Subsurface pit / shafts / trenches used for storage and disposal of solid and

radioactive wastes CME overview

• CME revised and submitted to NMED September 2011• CME addresses hazardous constituents in units, and VOC vapors in vadose zone• Alternatives considered – no action, and combinations of capping, excavation and

SVE• DOE radiological regulatory authority will be integrated with NMED selected

remedy LANL recommended alternative

• Evapo-transpiritive (ET) cap with bio-intrusion barrier and native vegetation• Targeted SVE• Long-term monitoring and maintenance

NMED review of Corrective Measures Evaluation and Draft Statement of Basis pending

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MDA-G Aerial View of FacilitiesMDA-G Aerial View of Facilities

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MDA-T Overview

Site background and operational history• Approximately 2 acres site• Four absorption beds operated from 1945 to 1967• Waste disposal shafts used from 1968 to 1975 for TRU waste disposal and after 1975 for

only LLW Four Absorption Beds

• 16 million gallons treated and untreated plutonium wastewater from DP West (mostly floor drains and decontamination water)

• 2 million gallons untreated tritium wastewater from DP East • Estimated to contain approx. 9.8 curies plutonium

Waste Disposal Shafts Located between absorption beds• ~64 shafts 2-, 6- and 8-ft diameters, 15 to 69 ft. deep , some with asphalt lining • Covered with 2 – 5 ft. of concrete and 4 – 6 ft. of crushed tuff• Mostly radioactive liquid waste mixed with Portland cement from 21-257 pugmill, some

shafts used for rinse water only• Some waste debris including 21 bathyspheres in 5 shafts and 8 55-gallon drums in 2 shafts • Estimated to contain 4,000 to 12,000 curies, americium, plutonium, uranium, and mixed

fission products

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MDA-T Overview

Current Investigation results• Elevated Pu239, 240 above residential and industrial screening action levels (SAL)

below the absorption bedso Concentrated below absorption beds and building 21-035 footprinto Depth is approximately 40’ below the ground surface

• VOCs, semi-volatile organic chemicals (SVOC) and other metals are near background or industrial soil screening levels (SSL), as appropriate

• Phase 2 screening showed pore gas is not a threat to the groundwater

• No samples directly from absorption beds but one sample from the shafts

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MDA-T Overview

Remaining Work • Vadose Zone Moisture Monitoring Work Plan but not conducted

o Test pit, 4 angled boreholes, 1 or 2 deep vertical boreholeso One deep vapor well near 21-257

• Corrective Measures Evaluation (CME)o CME provides remedy alternatives analysis and a preferred remedy

Range of alternatives include capping ($105M) to full excavation ($1.2B)o NMED selects final remedy and issues a Statement of Basiso NMED’s selection must undergo public comment period

• Wells R-64 and R-65• Integrated approach for MDAs A&T (possible)• Performance Assessment and Composite Analysis (PA/CA)

o DOE regulates radiological hazards and integrates with NMED

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MDA-T at TA-21 Views

Phase I Investigation Report completed in September 2006

Need CME

Expected engineering cover as remedy

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MDA-AB at TA-49

Operated from January 1960 – August 1961. Underground hydro-nuclear experiments evaluated the possibility of starting a nuclear reaction from accidental high explosive detonation

The Nuclear Environmental Site (NES), a Hazard Category 2 Nuclear Facility• Areas 1, 2 (Material Disposal Area AB [MDA AB]), and 4 include a subset of 82

shafts, approximately 3 acres. Depths ranged from 31 feet – 108 feet below ground surface and Ranged from 3 feet – 6 feet in diameter

• Area 3- Contains 13 shafts. No radiological materials used• Area 11- Radiochemistry Laboratory and Small Scale Experiments• Area 12- Bottle House and Cable Pull Test Facility

Areas Outside the NES• Areas 5, 6 and 10

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REMAINING IN THE 82 SHAFTS• Plutonium = 88 lbs. (40 kg)• Uranium-235 = 205 lbs. (93 kg)• Uranium 238 = 375 lbs. (170 kg)• Beryllium = 24 lbs. (11 kg)• Lead = 99 tons – shots were encased in lead

CONSUMED• High explosives: TNT, HMX (high melting explosive), and RDX (research

department explosive)

MDA-AB at TA-49

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MDA-AB at TA-49 Overhead

Investigation Area Outside NES

Investigation Area Inside NES