Table 6

Comparative Analysis of Remedial Alternatives for
Radiologically Contaminated Soils

 

Alternative

1. Protection of Human Health & Environment1

(after Federal institutional control)

2. Compliance with ARARs

3. Long-Term Effectiveness and Permanence2 4. Reduction of Toxicity, Mobility or Volume (TMV) by Treatment

5. Short-Term Effectiveness3

6. Implementability 7. Cost
1. No Action with Monitoring

Remedial action objectives not met

Residual Risk to future HWMF users:

50 years: 6.3E-02 (6.3E-02)

100 years: 2.0E-02 (2.0E-02)

Does not meet ARARs either during or following remediation Not Effective in achieving future use allowable exposure levels

No active reduction of TMV. All contaminated media remains on site

Natural reduction of toxicity by radioactive decay and dispersion only

Overall: Very Low

Remediation Risk Ranking:

  • Worker - 1 (9 person rem)
  • Community - 1 None

Readily implemented

Limited technical requirements

Limited administration

Overall: Very Simple

$844,000

2. Engineered Cell

  • Dispose soils above cleanup goals on site

Remedial action objectives met

Residual Risk to future HWMF users:

50 years: 4.8E-05 (1.5E-04)

100 years: 1.5E-05 (4.3E-05)

Remediation: Expected compliance with cleanup goal

Post-Remediation: Potential siting issue with State as all media remains on site in de facto rad waste disposal facility. Waiver required

Marginally Effective

Highest contaminated soil remains within cell

Permanence to prevent direct external exposure to all contaminated soils dependent on cover maintenance and zoning controls for perpetuity

No reduction of TMV through treatment

Natural reduction of toxicity over time (decay)

Source of direct external exposure shielded and contaminant mobility reduced by cover and liner system

Overall: Low

Remediation Risk Ranking:

  • Worker - 6 (168 person rem)
  • Community - 3 (4.4E-10)

Extremely intrusive remediation

Readily implemented/technically feasible

Complex administration requirements due to permitting (siting) issues for cell

Overall: Moderately Complex

$8,648,000

3. Moderate Excavation, Off-site Disposal, and RCRA Cap

  • Excavate/Dispose soils above secondary action level
  • Cap remaining soils above cleanup goals

Remedial action objectives met

Residual Risk to future HWMF users:

50 years: 4.5E-05 (5.1E-05)

100 years: 1.4E-05 (1.5E-05)

Remediation: Expected compliance with cleanup goal

Post-Remediation: Media remaining on site meets secondary action level; however, potential siting issue with State, which may require waiver

Effective (if cap maintained)

Highest contaminated soils permanently removed

Permanence to prevent direct external exposure to lower activity contaminated soils dependent on cap maintenance for 100 years

Reduction of TMV through offsite disposal

Additional toxicity and mobility reduction via cap

Overall: Medium

Remediation Risk Ranking:

  • Worker - 2 (45 person rem)
  • Community - 5 (2.6E-07)

Partially intrusive remediation

Readily implemented/technically feasible

Above average administration requirements due to offsite disposal volumes and cap permitting

Overall: Moderately Complex

$14,915,000

4. Large-Scale Excavation and Offsite Disposal

  • Excavate/Dispose soils above cleanup goals

Remedial action objectives met

Residual Risk to future HWMF users:

50 years: 6.5E-05 (7.1E-05)

100 years: 2.0E-05 (2.1E-05)

Remediation: Expected compliance with cleanup goal

Post-Remediation: Expected compliance since all soils above remediation goals removed from site

Very Effective

Permanent

All contaminated soils above risk-based remediation goals removed

Institutional control period 50 years (vs. 100 years for other alternatives)

Substantial reduction of TMV through offsite disposal; however, no treatment is provided

Overall: Very High

Remediation Risk Ranking:

  • Worker - 4 (90 person rem)
  • Community - 6 (5.3 E-07)

Extremely intrusive remediation

Readily implemented/technically feasible

Above-average administration requirement due to large offsite disposal volumes

Overall: Moderately Complex

$24,032,000

5. Moderate Excavation, Soil Washing, Offsite Disposal, and RCRA Cap

  • Dispose >2800 pCi/g
  • Wash above secondary action level
  • Cap remaining soils above cleanup goals

Remedial action objectives met

Residual Risk to future HWMF users:

50 years: 4.5E-05 (5.1E-05)

100 years: 1.4E-05 (1.5E-05)

Remediation: Expected compliance with cleanup goal

Post-Remediation: Media remaining on site meets secondary action level; however, potential siting issue with State, which may require waiver

Effective (if cap maintained)

Highest contaminated soils removed

Permanence to prevent direct external exposure to lower activity contaminated soils dependent on cap maintenance for 100 years

Reduction of TMV through offsite disposal

Additional reduction in volume via soil washing

Additional toxicity and mobility reduction via cap

Overall: Relatively High

Remediation Risk Ranking:

  • Worker - 5 (120 person rem)
  • Community - 4 (8.8E-08)

Partially intrusive remediation

Readily implemented. Less technically feasible as soil washing of 137Cs not demonstrated. High remedial O&M

Above-average administration requirements due to large offsite disposal volumes, treatment technology, and cap permitting

Overall: Complex

$15,304,000

6. Moderate Vitrification and RCRA Cap

  • Vitrify soil above secondary action level
  • Cap remaining soil above cleanup goals

Remedial action objectives met

Residual Risk to future HWMF users:

50 years: 4.5E-05 (5.2E-05)

100 years: 1.4E-05 (1.6E-05)

Remediation: Expected compliance with cleanup goal

Post-Remediation: Highest soils vitrified and capped and effectively immobile; however, potential siting issue with State, which may require waiver

Effective (if cap maintained)

Highest contaminated soils permanently immobilized and then capped

Permanence to prevent direct external exposure dependent on cap maintenance for 100 years

Permanence to prevent leaching and inadvertent intrusion provided by vitrified mass

Greatest reduction of TMV via treatment

No soils transferred off site

Additional toxicity and mobility reduction via cap

Overall: Very High

Remediation Risk Ranking:

  • Worker - 3 (75 person rem)
  • Community - 2 (None)

Less-intrusive remediation of highest contaminated soils

Limited full-scale use. Promising field study results. High O&M and remediation time

Above-average administration requirements for technology and cap permitting

Overall: Very Complex

$19,554,000

1 Future HWMF user is assumed to be industrial/commercial. Risks are shown both with the drinking water pathway turned off and on (value in parentheses) for both 50 and 100 years of Federal institutional control.

2 Federal/BNL controls assumed to be effective during 50-year control period for all Alternatives.

3 The Remediation Risk Ranking has been presented from lowest (1) to highest (6).