An Alternative Disposal Method for Activated PCB Capacitors

N.M. BrachmannF.R. BrumwellS.W. Butala

S.Y. ChenJ.-J. Cheng

Presented at the DOE Accelerator Safety Workshop – SLACAugust 18, 2010

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IPNS Facility

450 GeV protons on uranium target neutron beams

Operated from 1981 to 2007

DOE ordered facility shutdown in December 2007

Subsequent activities focused on putting into safe condition

Priority for disposal of PCB materials

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PCB Electrical Capacitors

Poly-chlorinated biphenyl oil impregnated = hazardous

Capacitor inventory: Bld 391 (RCS) - 344, each weigh 126 lbs (57.2 kg)Bld 361 (linac) - 40, each weigh 140 lbs (63.5 kg)

- 32, miscellaneous sizes (605 kg)

Building 391 and 361 capacitors located in radiological areas

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Disposal Options

1. Mixed Waste Facility – EnergySolutions - Clive, Utah- NRC licensed to accept low-level radioactive waste- Awaiting EPA approval for capacitor waste treatment

2. Hazardous Waste Facility – Clean Harbors - Deer Park, TX - EPA approved for TSCA regulated waste - Must meet TX licensing requirements for radioactivity - Requires DOE authorization to be treated and disposed of

at a commercial facility

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Evaluation of Capacitor Activation – Bld 391

1. Bld. 391 capacitors initially evaluated with portable monitors– All results were background levels

2. Steel and brass hardware removed for gamma spectroscopy– Identified Mn-54, Co-57, Co-60, and Cs-137– Specific activity ~ 0.4 pCi/g

3. Gamma spectroscopy done for two bulk capacitors that had been located in highest neutron fluence– Identified Na-22, K-40, Mn-54, and Cs-137– Specific activities = 0.9 pCi/g and 1.9 pCi/g– Specific activities of Na-22, Mn-54 ~ 10% that of K-40, Cs-137

Total estimated activation products activity: < 1.87 microCi

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Evaluation of Capacitor Activation – Bld 361

1. Bld. 361 capacitors initially evaluated with portable monitors– All results were background levels

2. Steel and brass hardware removed for gamma spectroscopy– Identified no radioactive isotopes– Specific activity ~ 0.4 pCi/g

3. Gamma spectroscopy done for two bulk capacitors that had been located closest to 50 MeV linac beam loss point– Identified K-40 and Cs-137, only. – Specific activities = 0.4 pCi/g and 1.4 pCi/g, respectively– Used gamma spec system MDA to estimate Mn-54 and Na-22

Total estimated activation product activity: < 0.38 microCi

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Texas Department of Health Regulatory Limits

Exemption limits

Radioisotope Limit (µCi) Capacitor Content (µCi)Na-22 10 0.9Mn-54 10 1.3Co-57 100 0.001Co-60 1 0.01

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Approval Process for Disposal in Texas

Argonne submitted a report that evaluated the induced radioactivity in PCB capacitors (S. Butala and F. Brumwell)

Clean Harbors anticipated they could accept the capacitors, and forwarded request and report to Texas Department of Health

State concurred that proposed shipments would contain radioactivity below the exemption limits

Clean Harbors submitted a price quote to Argonne which provided basis for significant cost savings

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ALARA Analysis

RESRAD analysis for both disposal options done by J.-J. Cheng and S.Y. Chen of Argonne

Evaluated landfill disposal of metals following incineration (Clean Harbors) or heat treatment (EnergySolutions)

Worst-case scenario: subsistence farming 30 years post-burial

Maximum individual dose: 0.021 mrem/year

Estimated collective dose to workers and public: 4E-4 person-rem

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Requirements for DOE Authorized Release

Per DOE Order 5400.5, release of property with residual radioactivity must:– Be evaluated, characterized, and if appropriate, decontaminated– Residual radioactivity must be as near background as practical– Releases be certified, verified, documented, and reported

Release of waste to a non-LLRW disposal facility must:– Meet authorized limits that assure public doses << 25 mrem/year– Have authorized release limits approved by DOE– Have protocols for survey and review of clearance– Authorized clearance limits should be coordinated with NRC or

Agreement State reps

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Additional Requirements for RCRA or TSCA Material

Authorized limits must:- Be assessed via ALARA process to optimize risk and benefits- Ensure groundwater is protected- Ensure the TSDF not require future remediation- Be acceptable to TSDF authority and applicable State reps

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Conclusions

First ever authorized release project at Argonne

DOE approved the proposed disposal plan

Successfully working with stakeholders

Capacitors were shipped to Clean Harbors

Following incineration, residues buried in RCRA licensed landfill owned/operated by Clean Harbors

Cost savings versus disposal at mixed waste facility: $950k