ZS-2019-0058, Clean Concrete Disposition at Zion
| ML19176A074 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 06/17/2019 |
| From: | Gerard van Noordennen ZionSolutions |
| To: | Document Control Desk, Office of Nuclear Material Safety and Safeguards |
| References | |
| ZS-2019-0058 | |
| Download: ML19176A074 (5) | |
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ZIOI\1lSOLUTIONSu-c _ _ _ _ _ _ __
June 17, 2019 ZS-2019-0058 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Zion Nuclear Power Station, Units 1 and 2 Facility Operating License Nos. DPR-39 and DPR-48 NRC Docket Nos. 50-295 and 50-304
Subject:
Zion Clean Concrete Disposition at Zion The purpose of this letter is to inform the NRC of ZionSolutions (ZS) plans for the disposition of the remaining Clean Concrete Demolition Debris (CCDD) and use of soil originating from off-site in accordance with Revision 2 to the Zion License Termination Plan (LTP). We have reviewed this plan against the LTP License Condition and have determined the plan is consistent with LTP, Rev 2.
The path forward, following completion of the NRC Confirmatory Survey of the Power Block survey units, is to remove the soil from both Containment basements and then reuse the same material as fill for excavations and grading in the surrounding Power Block survey units. Once the containment basements are empty, the remaining CCDD, currently stored in survey units 10214 and 12205, will then be placed in the Containment basements and covered with a minimum of3-feet of soil in accordance with the Zion LTP, Rev.2, Chapter 6, section 6.16. The final end-state grade of all survey units will undergo Final Status Survey (FSS) to verify compliance with the Operational Derived Concentration Guideline Levels (DCGLs) for soils.
A detailed description of the plan is provided below.
CONTAINMENT BASEMENT CLEAN FILL The soil that currently resides within the footprints of the two Containment basements is fill imported to the Zion site from an approved off-site non-radiological source. Section 5.7.1.7 of LTP Chapter 5 is titled, "Reuse of Excavated Soils." This section of the LTP addresses any restrictions that are imposed on where soil can be used. In this section, ZS commits that it will "not stockpile and store excavated soil originating from on-site for reuse as backfill in basements." The section also addresses the survey protocol required to use soils indigenous to Zion as backfill in excavations created to expose and remove subsurface commodities. Finally, the section addresses the survey requirements necessary to "introducing off-site material to Zion for use as backfill in a basement, or for any other use." The soils that were used to backfill the Containment basements were from an off-site source and were surveyed accordingly.
101 Shiloh Boulevard, Zion* IL 60099 (224) 789-4016
- Fax: (224) 789-4008
- www.zionsolutionscompany.com
ZionSolutions, LLC ZS-2019-0058 Page 2 of 5 Prior to demolition, the Containment basements were not only surveyed for compliance with the unrestricted release criteria, but both were also surveyed to comply with a continuing characterization commitment from LTP Chapter 5, Section 5.3.4.4. The objective of the continuing characterization survey was to assess the radiological condition of the exposed steel liners above the 565-foot elevation after the contaminated concrete had been removed. The liner was subjected to smear samples and beta scans to ensure that the liners were adequately decontaminated prior to performing FSS. The locations for taking samples and/or measurements were biased toward locations with the highest potential for the presence of loose or fixed contamination. The survey results from both Containments indicated no detectable loose contamination greater than 1,000 dpm/I00cm2 .
FSS was subsequently completed in both basements and compliance was demonstrated in accordance with the process described in LTP Chapter 5, Section 5.5. For the surfaces above the 565-foot elevation, 164 measurements were taken in both Containments representing 100% areal coverage of the liner surface. All measurements were less than the Operational DCGLs for Containment basement surfaces, with the exception of one measurement taken in Unit 1
- Containment (SOF of 1.1565). The SOF (based on the Operational DCGL) for a systematic or a judgmental measurement/sample(s) may exceed one without remediation as long as the survey unit passes the Sign Test and the mean SOF (based on the Operational DCGL) for the survey unit does not exceed one. This was the case in Unit 1 Containment.
Upon completion ofFSS, both Containment basements were subjected to Isolation and Control (I&C) measures in accordance with procedure ZS-LT-300-001-003, "Isolation and Control for Final Status Survey." These measures are designed to prevent the reintroduction of a source term into a FSS unit where compliance has been demonstrated in an end-state configuration.
During the demolition of the Containment exteriors (exteriors were surveyed clean to Unconditional Release levels prior to demolition) and the period of time afterwards, I&C controls ensured that no additional radioactive material not already quantified by the FSS was introduced into the basements. Consequently, as the soil was free of residual radioactivity when it was introduced to the basement footprints and, due to the fact that both basements were surveyed and found to be free of loose contamination, there is a very low probability that the soils used to fill the Containment basements became cross-contaminated to levels greater than the Operational DCGLs for subsurface soils. In short, clean fili was introduced to clean
(<1,000 dpm/100 cm2) containment basements under procedural I&C controls throughout.
To confirm this premise, scoping surveys were performed on the current exposed soil surfaces within both Containment footprints. The surface soils in both Containment footprints were 100% scanned and no detectable radioactivity was identified. A total of 11 surface soil samples and 15 subsurface soil samples at depths of 3 to 23 feet were taken of the fill from the two containments, as well as one below grade water sample from each containment. No plant-derived radionuclides were positively detected by the on-site gamma spectroscopy analysis. Ten percent ( 10%) of the soil samples (combination of surface and subsurface) were sent to an off-site laboratory for analysis for Hard-to-Detect (HTD) radionuclides. With the exception of one sample that showed positive results for tritium (H-3), no plant derived HTD Radionuclides of Concern (ROC) were positively identified. The concentration ofH-3 in the one soil sample was detectable, however at a concentration within the Minimum Detectable Concentration (MDC) margin of error for the instrument and a small fraction of the Operational DCGL. The
ZionSolutions, LLC ZS-2019-0058 Page 3 of 5 water sample taken in the Unit 2 Containment footprint showed detectable H-3 at a concentration of 314 pCi/liter. However, this concentration is a factor of 6 times less than the Offsite Dose Calculation Manual release criteria.
ZS plans to remove the soil from the Containment basements and use the excavated soil as fill to backfill excavations and to establish grade in the survey units surrounding the Containment footprints. The fill can also be used without restriction, anywhere within the impacted area of the site. The bases for this conclusion are as follows:
- The soil was clean fill brought to the site from a non-radiological off-site source.
- The Radiological Assessment performed on the fill from the non-radiological off-site source showed no detectable plant-derived radioactive materials in the fill material.
e Prior to introducing the fill, the Containment basements were surveyed to show no loose contamination.
- Prior to introducing the fill, the Containment basements were successfully subjected to FSS and compliance with the unrestricted release criteria was demonstrated.
- Prior to performing FSS, I&C controls in accordance with procedure ZS-LT-300-001-003 were implemented. I&C controls on the Containment basements has been uninterrupted to date.
- No source term was introduced into the Containment basement footprints following implementation of I&C.
- Due diligence scoping soil and water samples were acquired and analyzed for plant-derived radionuclides to ensure the fill would meet surface and subsurface soil DCGLs.
- A review was conducted for these planned activities to verify compliance with the LTP License Conditions.
- The survey units where the fill from the Containment basements will be placed will be subjected to FSS and compliance will be demonstrated in accordance with the approved process in LTP Chapter 5.
Once the fill is excavated, ZS intends to place the remaining CCDD currently stored in Survey Units 10214 (parking lot) and 12205 into the Containment basements for use as fill inside of a basement as described in LTP Chapter 6, Section 6.16.
CLEAN CONCRETE DEMOLITION DEBRIS (CCDD)
Unrestricted release surveys of concrete from structures approved for use as CCDD in accordance with Section 2.1.1 of TSD 17-010, "Final Report - Unconditional Release Surveys at the Zion Station Restoration Project" (e.g. Turbine, Crib House, Containment Exterior) were performed using 'MARSAME' compliant procedures and Lower Limits of Detection (LLDs) in accordance with ZS procedure ZS-LT-400-001-001, "URS of Materials Equipment and Secondary Structures." By performing surveys in situ with hand held survey instruments via a graded MARSAME approach, LLDs in the 2,500-3,000 dpm/100 cm2 range were determined acceptable. TSD 17-010 was previously submitted to the NRC and it was incorporated as a
ZionSolutions, LLC ZS-2019-0058 Page 4 of 5 license condition for the approval of Revision 2 of the Zion LTP. Following completion and documentation of these surveys, in accordance with ZS approved processes and procedures for the unrestricted release of materials, CCDD could be disposed of to an off-site source as a "non-radioactive" material or, with appropriate I&C, used as fill in building basements in accordance with LTP Chapter 6, Section 6.16.
Although no detectable radioactivity was observed in the unrestricted release surveys of the CCDD, when used as fill in a basement, ZS will assign a dose for reused concrete as specified in LTP Chapter 6, Table 6-53 and in accordance with section 8 ofTSD 14-010, "RESRAD Dose Modeling for Basement Fill Model and Soil DCGL and Calculation of Basement Fill Model Dose Factors and DCGLs."
CONCLUSION ZionSolutions has concluded, based on its technical reviews and procedural process for assessing LTP compliance (i.e. LTP license condition review and associated forms), that the path forward of removing fill from the Containment basements and placing it in other survey units, and replacing the fill in the basements with CCDD is fully compliant with LTP Revision 2.
If the NRC has any questions regarding our proposed plan for disposition of CCDD or would like to discuss any element of this proposed plan, please contact us before June 27, 2019.
Respectfully, r7/J ~
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Gerard van Noordennen Senior Vice President Regulatory Affairs cc: John Hickman, U.S. NRC Senior Project Manager Service List
Zion Nuclear Power Station, Unit 1 and 2 License Transfer Service List cc:
Ken Robuck Regional Administrator President and CEO U.S. NRC, Region III EnergySolutions 244 3 Warrenville Road 299 South Main Street, Suite 1700 Lisle, IL 60532-4352 Salt Lake City, UT 84111 Steven A. Reynolds John Sauger Manager, Nuclear Facility Inspection President and CNO Division of Nuclear Safety Reactor D&D Illinois Emergency Management Agency EnergySolutions 245 W. Roosevelt Road, Units 55 & 56 121 W. Trade Street, Suite 2700 West Chicago, Illinois 60185 Charlotte, NC 28202 Kelly F. Grahn, Senior Health Physicist Bruce Hinkley Illinois Emergency Management Agency Senior Vice President Division of Nuclear Safety D&D Operations 245 W Roosevelt Road, Building 8, Suite 55 EnergySolutions West Chicago, IL 60185 121 W. Trade Street, Suite 2700 Charlotte, NC 28202 William P. Mazzeno Emergency Management Coordinator Gerard van N oordennen Lake County Emergency Management Agency Senior VP Regulatory Affairs 1303 N. Milwaukee Avenue EnergySolutions Libertyville, IL 60048-1308 121 W. Trade Street, Suite 2700 Charlotte, NC 28202 John E. Matthews Morgan, Lewis & Bockius LLP Jerry Houff 1111 Pennsylvania A venue, NW General Manager Washington, DC 20004 ZionSolutions, LLC 2701 Deborah Avenue Zion, IL 60099 Russ Workman General Counsel EnergySolutions 299 South Main Street, Suite 1700 Salt Lake City, UT 84111