ML020030205
| ML020030205 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 01/04/2002 |
| From: | Gibson K NRC/NRR/DIPM/RSRSEPB |
| To: | Gramm R NRC/NRR/DLPM/LPD4 |
| References | |
| +KBR1SISP20050809, TAC MB1463 | |
| Download: ML020030205 (6) | |
Text
January 4, 2002 MEMORANDUM TO: Robert A. Gramm, Chief Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM: Kathy Halvey Gibson, Chief/RA/
Emergency Preparedness and Health Physics Section Reactor Safeguards, Radiation Safety, and Emergency Preparedness Branch Division of Inspection Program Management Office of Nuclear Reactor Regulation
SUBJECT:
SAFETY EVALUATION FOR A REQUEST TO DISPOSE OF CONTAMINATED DEMOLITION DEBRIS FROM THE BIG ROCK POINT NUCLEAR PLANT PURSUANT TO 10 CFR 20.2002 The Emergency Preparedness and Health Physics Section has completed its review of the Consumers Energy Companys (the licensee) request, pursuant to 10 CFR 20.2002, dated March 14, 2001, as supplemented on May 18, and June 20, 2001, to dispose of 42.25 million pounds of demolition debris in a State of Michigan licensed Type II landfill. The calculated annual radiological dose to a member of the public or worker from the disposal of this material is less than 1 mrem.
Based on our review, we find that the licensee has provided adequate justification to support its request. The attachment to this memorandum provides our evaluation of the licensees application.
This completes our review under TAC No. MB1463.
Docket No. 55-155
Attachment:
Safety Evaluation CONTACT: Stephen Klementowicz, NRR/DIPM/IRSB/EP/HP (301) 415-1084
January 4, 2002 MEMORANDUM TO: Robert A. Gramm, Chief Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM: Kathy Halvey Gibson, Chief /RA/
Emergency Preparedness and Health Physics Section Reactor Safeguards, Radiation Safety, and Emergency Preparedness Branch Division of Inspection Program Management Office of Nuclear Reactor Regulation
SUBJECT:
SAFETY EVALUATION FOR A REQUEST TO DISPOSE OF CONTAMINATED DEMOLITION DEBRIS FROM THE BIG ROCK POINT NUCLEAR PLANT PURSUANT TO 10 CFR 20.2002 The Emergency Preparedness and Health Physics Section has completed its review of the Consumers Energy Companys (the licensee) request, pursuant to 10 CFR 20.2002, dated March 14, 2001, as supplemented on May 18, and June 20, 2001, to dispose of 42.25 million pounds of demolition debris in a State of Michigan licensed Type II landfill. The calculated annual radiological dose to a member of the public or worker from the disposal of this material is less than 1 mrem.
Based on our review, we find that the licensee has provided adequate justification to support its request. The attachment to this memorandum provides our evaluation of the licensees application.
This completes our review under TAC No. MB1463.
Docket No. 55-155
Attachment:
Safety Evaluation CONTACT: Stephen Klementowicz, NRR/DIPM/IRSB/EP/HP (301) 415-1084 DISTRIBUTION EP&HP Reading File D. Wrona B. Jorgensen, RIII C. Craig, NMSS S. Klementowicz K. Gibson ADAMS Accession Number: ML020030205 DOCUMENT NAME: C:\Program Files\Adobe\Acrobat 4.0\PDF Output\Big Rock Point 20-2002.wpd OFFICE NRR/DIPM NRR/DIPM NAME SKLEMENTOWICZ KGIBSON DATE 1/ 4 /2002 1/ 4 /2002
OFFICIAL RECORD COPY SAFETY EVALUATION BY THE EMERGENCY PREPAREDNESS AND HEALTH PHYSICS SECTION OFFICE OF NUCLEAR REACTOR REGULATION BIG ROCK POINT NUCLEAR PLANT DOCKET NO. 55-155 1.0 Introduction By letter dated March 14, 2001, as supplemented on May 18, and June 20, 2001, Consumers Energy Company (the licensee), submitted a request, pursuant to 10 CFR 20.2002, to dispose of 42.25 million pounds of predominately concrete debris in a State of Michigan licensed Type II landfill.
The Big Rock Point Nuclear Plant was permanently shutdown on August 29, 1997, for decommissioning. As part of the decommissioning process, the licensee plans to dismantle the individual structures after they have been decontaminated and radiologically surveyed. The licensee estimates that there will be total of 84.5 million pounds of predominately concrete debris from the entire decommissioning project. Approximately one half of this material is non-impacted (i.e., has never had the potential for neutron activation or exposed to licensed radioactive material). The other half has a potential to contain residual licensed radioactive material and/or neutron activation products in a limited quantity, and is the subject of this evaluation pursuant to 10 CFR 20.2002.
2.0 Evaluation The licensee, as required by 10 CFR 20.2002, performed a comprehensive physical and radiological evaluation of the demolition debris material.
The demolition debris will originate from the demolition and removal of structures and paved surfaces at the plant site, which includes flooring materials, concrete, rebar, roofing materials, structural steel, soils associated with digging up foundations and concrete and/or asphalt pavement or other similar solid materials.
The physical form of the material will be that of bulk material with various screen sizes ranging from particles the size of sand up to occasional monoliths with a volume of several cubic feet.
The licensee, for the calculations, assumed the material to be a homogenous mixture with a density of 150 pounds per cubic foot. The material will be dry solid waste containing no absorbents or chelating agents. The material will meet all State of Michigan disposal criteria and is subject to inspection by State Inspectors.
The licensee estimates that the mass of both contaminated and non-contaminated material will total approximately 84.5 million pounds. With an assumed density of 150 pounds per cubic foot, the estimated volume of material disposed at the State of Michigan licensed landfill will be approximately 563,000 cubic feet. This value represents approximately two percent of the annual volume of waste disposed at the landfill that is expected to receive the material.
The disposal of the material is expected to be completed within one year. The material will not be isolated or dedicated to a single burial cell at the landfill. Rather, it will be co-mingled with other landfill materials. The material will be covered with an interim 6-inch layer of soil each day, in accordance with landfill requirements.
The licensees radiological evaluation of the buildings, structures, and other materials to be disposed, included over 200 core borings in locations expected to have the highest contamination potential. Each core material was analyzed on-site by gamma spectrometry and direct radiation survey to determine what radio nuclides are present and how far the contaminants have penetrated into the concrete. In addition, portions of 14 core samples were analyzed by an off-site laboratory (General Engineering Laboratories) at detection levels consistent with environmental monitoring using alpha and gamma spectrometry and liquid scintillation monitoring to analyze for the presence of the following radionuclides:
Ac-227 Ac-228 Ag-108m Ag-110m Am-241 C-14 Cd-109 Ce-144 Cm-242 Cm-243/244 Co-60 Cs-134 Cs-135 Cs-137 Eu-152 Eu-154 Fe-55 H-3 I-129 K-40 Mn-54 Ni-59 Ni-63 Nb-94 Pb-214 Pm-147 Pu-241 Pu-238 Pu-239/240 Ru-106 Sb-125 Sr-90 Tc-99 U-233/234 U-235/236 U-238 Zn-65 The results of the laboratory analysis identified only Co-60, Cs-137, and H-3. In addition, K-40, Pb-214, U-233/234, and U-238 were identified, but at levels that were indistinguishable from naturally occurring background levels measured in plant concrete samples that were not contaminated by licensed radioactive materials.
Based on the radiological characterization of the buildings and structures to be demolished, the licensee calculated the approximate amount of licensed radioactive material that would be generated. For the 42.25 million pounds of debris, the total amount of radioactivity by radionuclide is as follows:
Radionuclide Total Activity (mCi)
Co-60 16.0 Cs-137 3.3 H-3 152 Total 171 The value of 171 mCi represents the realistic amount of licensed radioactive material that is expected to be contained in the 42.25 million pounds of debris. However, the licensee performed a more conservative bounding calculation which used a principal gamma emitter concentration of 5 pCi/gm for licensed radioactive material contained in the debris. Adjusting 2
the total gamma activity upward to a bounding principal gamma emitter concentration value of 5 pCi/gm results in the following values:
Radionuclide Total Activity (mCi)
Co-60 80.0 Cs-137 16.5 H-3 760 Total 856 For this 10 CFR 20.2002 application, the licensee used the bounding value of 5 pCi/gm principal gamma emitter concentration as a limit to ensure that radiological dose to workers and members of the public is kept As Low As Reasonably Achievable (ALARA). To ensure that the 5 pCi/gm principal gamma emitter limit is not exceeded, radiological surveys will be performed on structural surfaces prior to demolition to verify that radioactive surface contamination does not exceed 5000 dpm/100 cm2 averaged over areas appropriate for the detection system used and all demolition debris will be monitored by a bulk assay radiation detection system with an alarm setpoint established at or below the 5 pCi/gm principal gamma emitter limit prior to disposal.
The licensee performed radiological calculations which used the 5 pCi/gm principal gamma emitter concentration limit as the concentration of licensed radioactive material in the 42.25 million pounds of demolition debris being transported and disposed of in a State of Michigan licensed Type II landfill. To perform these calculations, the licensee used readily available commercial dose assessment codes (MicroShield, Version 5.03, from Grove Engineering and RESRAD, Version 6.0, from the U.S. Department of Energy) that are acceptable to the NRC.
Dose assessments were performed for the types of individuals which have the potential to receive the maximum dose: Transport worker, Landfill worker, and Landfill resident / Farmer.
Individual Annual Dose (mrem)
Transport Worker 0.366 Landfill Worker 0.290 Landfill Resident / Farmer 0.009 In addition to the NRC staffs evaluation of the licensees data and radiological assessment the staff also performed independent dose assessment calculations. This evaluation used the RASCAL code and the licensees radionuclide survey data, which confirmed the acceptability of the licensees calculations. The staffs calculated doses were in agreement with the licensees calculations.
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3.0 Conclusion The NRC staff finds the licensee's application to dispose of approximately 42.25 million pounds of demolition debris in a State of Michigan licensed Type II landfill will result in a calculated potential annual dose to a worker or a member of the public of less than 1 mrem. This calculated dose is well within the 10 CFR Part 20 annual dose limit of 100 mrem and less than the annual dose limit of 25 mrem for decommissioning which will allow for license termination and unrestricted use of the land. Additionally, the material will meet all State of Michigan disposal criteria and is subject to inspection by State Inspectors.
The NRC staff finds the licensees application, pursuant to 10 CFR 20.2002, will not have a significant impact on workers, the public, or the environment and is acceptable.
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