ML102180372

Presentation Slides from July 29, 2010, Meeting with Humboldt Bay Power Plant

ML102180372
Person / Time
Site:	Humboldt Bay
Issue date:	07/29/2010
From:	NRC/FSME
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Download: ML102180372 (40)

Text

Humboldt Bay Power Plant NRC presentation July 29, 2010

Agenda

" Introductions and purpose of this meeting

• HBPP Site Orientation

" Alternate Disposal Method Request(s)

" Reactor Vessel Transportation and Disposal

" DCGL's and LTP

HBPP Site

• 2 Operating Steam Generation Fossil Units 9 2 backu pGas Turbines

• Operating ISFSI

• Construction of New Generation Facility

• Unit 3 Nuclear Plant decommissioning

• Preparation for Units 1 and 2 decommissioning

Alternate Disposal Request

" Purpose of the Alternate Disposal Request (submitted April 1, 2010)

• Schedule of Units 1/2 decommissioning

" Proposed answers to questions on submittal

" Travel Route from Eureka CA to Grand View Idaho (HBPP to USEI)

" Weather or road re-routing of trucks

" Potential future alternative disposal request(s)

Potential Alternate Disposal Requests

• Open air demo limits established at HBPP Unit 3 will require concrete shaving

• Resulting concrete structures will be very low concentration limits, consistent with current request

• Soils concentrations of SNM very localized

• Potential that an additional 1000 shipments will meet current alternate disposal concentration criteria

Potential Alternate Disposal Requests e State of Calif Department of Toxic Substances Control (DTSC) clean up standards are based on combined cancer risk model, rather than a dose based model

• Increase total shipments

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I Half Life Decay Half Life Decay Radionuclide (Years) Mode Radionuclide (Years) Mode Am-241 4.32E+02 a, y 1-129 1.57E+07 V3-, y C-14 5.73E+03 Nb-94 2.03E+04 3-, 'y Cm-243 2.91E+01 a, y Ni-59 7.50E+04 F Cm-244 1.81E+01 a, 7 Ni-63 1.OOE+02 Cm-245 8.50E+03 a,y Np-237 2.14E+06 aqy Cm-246 4.75E+03 aq, Pu-238 8.78E+01 a, y Co-60 5.27E+00 13-, y Pu-239 2.4 1E+04 a, y Cs-137 3.02E+01 Pu-240 6.60E+03 a, Y Eu-152 1.36E+01 f3-, y Pu-241 1.44E+01 Eu-154 8.80E+00 J3,, y Sr-90 2. 86E+O1 3-H-3 1.23E+O I Tc-99 2.13E+05 P-,rY

Sorc Ter Absrcin Cot Dos modlin objetive Deive sigl nucid DCI onl fo detecte radiouclids, an Acon fo no-etce Ssite-specific poental raincie when comparSingto anu a dos limit

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Scenario Development, Cont..

Industrial worker scenario chosen for use with RESRAD for soil DCGL derivation:

RESRAD chosen because of subsurface soil contamination, Industrial worker is most appropriate scenario for foreseeable future, and Dose contribution due to detected soil radionuclides indistinguishable from background after 100 years.

Scenan'o Development, Cont Alternative critical groups and exposure scenarios have been considered:

A resident farmer establishes occupancy after release of site from Industrial Area use, and If the site license is terminated at uniform industrial worker scenario DCGLs, the site is in compliance with the regulatory limit 32 years later using a resident farmer scenario.

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Derivation of Soil DCGLs, Cont.

A RESRAD simplified mathematical hydrogeological model was derived based on existing knowledge-

" Site studies define soil and aquifer profiles from surface to potable water aquifer,

" Approximately 400 ft from surface to potable water aquifer, Several clay layers exist between surface and potable water aquifer, and Brackish water aquifers exist above the clay layers.

Peak Dose at 1 pCi/g Nuclide (mrem/vrl DCGL (DCi/gl AM-241 1.76E-02 1.42E+03 C-14 4.98E-06 5.02E+06 Cm-243 7.78E-02 3.21E+02 Cm-244 6.82E-03 3.67E+03 Cm-245 5.44E-02 4.60E+02 Cm-246 1.26E-02 1.98E+03 Co-60 1.64E+00 1.52E+01 Cs-137 3.79E-01 6.60E+01 Eu-152 7.40E-01 3.38E+01 Eu-1S4 7.97E-01 3.14E+01 H1-3 8.66E-06 2.89E+06 1-129 1.95E-03 1.28E+04 Nb-94 1.09E+00 2.29E+01 Ni-59 6.05E-07 4.13E+07 Ni-63 1.65E-06 1.52E+07 Npm-237 1.31E-01 1.91E+02 Pu-238 1.09E-02 2.29E+03 Pu-239 1.21E-02 2.07E+03 Pu-240 1.21E-02 2.07E+03 PU-241 4.11 E-04 6.08E+04 Sr-90 3.1OE-03 8.06E+03 I ol 1,

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Dose Conversion Factor Radionuclide (mrem/vr Der dnm/100 cm 2) DCGL (dDm/100 cm 2)

H-3 6.07E-07 4.12E+07 C-14 2.05&-05 1.22E+06 Ni-59 3.09E-07. 8.09E+07 Co-60 1.54E-03 1.62E+04 Ni-63 8.08F,07 3.09E+07 Sr-90 2.01E-04 1.25E+05 Nb-94 1.06E-03 2.36E+04 Tc-99 2.08E-06 1.20E+07 1-129 2.74E-03 9.12E+03 Cs- 137 4.44E-04 5.63E+04 Eu-152 7.57E-04 3.30E+04 Eu-154 8.26E-04 3.03E+04 Np-237 5.28E-02 4.73E+02 Pu-238 7.01E-03 3,57E+03 Pu-239 S.I7E-03 3.06E+03 Pu-240 7.26E-03 3.44E+03 Pu-241 1.38E-04 1.81E+05 Ani-241 8.34E-03 3.OOE+03 Cm-243 5.20E-03 4.81E+03 Cm-244 3.97E-03 6.30E+03 Cm-245 8.60E-03 2.88E+03 Cm-246 2.08F_,-02 1.20E+03

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Area Factor= DCGLEMc DCGLW metodg S-of 5

, and

Humboldt Bay RPV Project NRC Update 7/-29/2010

Reactor Pressure Vessel Project Goal

• Package and Transport HBPP Reactor vessel as an single component package as an LSA shipment in a DOT IP2 package

Plant History

. 65 MW GE Boiling Water Reactor mApprox 5E5 years effective run life m.Reactor last run in 1976 with approx 35 years of radioactive decay

Initial Characterization

" Performed in mid 1990s by TLG to support cost estimate for decommissioning

" Activation analysis for characterization was performed on internals and vessel

• This results in conservative estimates of the part 61 classification of activated internals

Current Approach

• Normalize the prior activation analysis by dose rate

" Determine final classification of vessel based on total activity averaged over metal volume in accordance with the BTP

• Perform partial segmentation of internals to remove items to meet the 1R at 3 meter unshielded dose limit

Regulatory Basis of Approach m 10 CFR 71.14 concerning transport of LSA materials

• NRC Branch Technical Position (BTP) on Concentration Averaging 1995

Segmentation discussion Classification

- Remove internal components to meet 10CFR61 classification as a Class A package

- Remove additional internal components to meet the 1R at 3 meter limit of 10CFR71. 14

ALARA Basis for Approach

• Segment GTCC waste and place in ISFSI

" Segment B/C waste and store on-site until disposal option becomes available

" Reduce dose consequence- to workers by minimizing segmentation of internals

" Reduce Radiological risk in transportation by minimizing truck quantities of less stable packaging alternatives

Project Schedule m Selected RPV removal contractor June 2010 .7.

• Complete RPV characterization Oct 2010

" Mobilize for site work March 2011

• Ship reactor vessel February 2012

Summary

• Minimum segmentation is the ALARA thing to do.

m Making a single disposal package is the ALARA thing to do.

• The single package results in safety to the public.