ML19084A064
| ML19084A064 | |
| Person / Time | |
|---|---|
| Site: | PROJ0736 |
| Issue date: | 11/01/2018 |
| From: | Lloyd Desotell Division of Decommissioning, Uranium Recovery and Waste Programs |
| To: | |
| L DESOTELL DUWP | |
| Shared Package | |
| ML19084A063 | List: |
| References | |
| Download: ML19084A064 (8) | |
Text
Hanford Waste Management Area C WIR Evaluation 11-01-2018 DOE-NRC Teleconference Summary Department of Energy (DOE) Attendees: Jan Bovier (DOE-ORP), Chris Kemp (DOE-ORP)
Nuclear Regulatory Commission (NRC) Attendees: Hans Arlt, Dave Esh, Lloyd Desotell DOE Contractor Attendees: Sunil Mehta (INTERA), Matt Kozak (INTERA), Keith Quigley (Veolia), Doug DeFord (WRPS), Mike Connelly (TecGeo), DJ Watson (WRPS), Jim Field (WRPS), Benjing Sun (Intera).
Member of the Public Attendees: Jeff Burright (Oregon Department of Energy) Tom Sicilia (Oregon Department of Energy)
The following topics regarding NRCs review of the Draft Waste Incidental to Reprocessing (WIR) Evaluation for Closure of Waste Management Area C (WMA C) at the Hanford Site were discussed during a November 01, 2018 teleconference. Not all the items identified were discussed due to time constraints. These remaining items will be discussed on a future teleconference.
This teleconference was open to the public. The call in information for this teleconference was posted on the following DOE Hanford webpage:
https://www.hanford.gov/page.cfm/WasteManagementAreaC Exposure Scenarios
- 1. The rationale for the future land use assumptions was discussed in addition to the procedure to determine when an exposure scenario is not consistent with the reasonably anticipated future land use within the Inner Area of the Central Plateau. DOE stated that the land-use information can be found in the DOE/EIS-0222-F (Final Hanford Comprehensive Land-Use Plan Environmental Impact Statement), which is discussed in Section 1.5 of the PA document.
- 2. The rationale for assuming the farmer scenario represents the maximally exposed individual was discussed. DOE stated the Tank Closure and Waste Management EIS evaluated several scenarios for the groundwater pathway and found residential farmer was most conservative of those compared. DOE provided following text that supports the assumptions made and the rationale for this decision.
[The resident farmer scenario was developed to calculate the radiological dose to a maximally exposed individual from all exposure pathways for the purpose of performance assessment calculations at the Hanford Site. Conceptually, this agricultural scenario assumes that the resident farmer lives and works at the edge of the Hanford site, inhales the local air, is subject to external exposure to the contaminated ground, and ingests the locally produced vegetables, meat, poultry, egg and dairy products to the maximal level, which could be plausibly sustainable DOE-NRC 11-01-18 WMA C 1lPage WIR Teleconference Summary
at the Hanford Site. This all-pathways farmer scenario has been applied in many performance assessment and risk assessment projects prior to the WMA C performance assessment. It was described in the Exposure Scenarios and Unit Factors for Hanford Tank Waste Performance Assessments (HNF-SD-WM-TI-707 Re. 5, 2007) - among all the exposure scenarios evaluated, the All Pathways Farmer is the most conservative non-Native American scenario. Additionally, the resident farmer scenario was developed and described as the most conservative exposure scenario among the four types of receptors considered in the Final Tank Closure & Waste Management Environmental Impact Statement for the Hanford Site (DOE/EIS-0391, 2012).]
- 3. The farmer-type receptor scenarios were discussed. NRC staff indicated that for these scenarios, the assumed infiltration rates should include irrigation that would be applied to the crops. DOE stated that sensitivity cases were run that vary infiltration rates. NRC staff asked where farmers in the region obtain water, DOE replied that it is derived from the Columbia River and groundwater wells. DOE stated that assumptions are discussed in detail in the PA document (page 6-147).
- 4. NRC staff asked DOE to describe how the exposure scenarios implemented incorporated past experience and site usage. DOE stated that farming was not conducted in the Central Plateau previously. DOE stated that the 1999 Environmental Impact Statement includes a map of farming. DOE stated that previous farming irrigation was conducted via surface water diversions.
- 5. NRC staff indicated that DOE may want to consider the buildup of contamination in soils from irrigation in their dose modeling for long-term impacts. DOE stated that they looked into buildup during modeling efforts at the Integrated Disposal Facility and the impact was not significant because technetium was the primary contaminant.
- 6. NRC staff asked if there is any daylighting of groundwater originating in WMA-C at more distant locations prior to mixing with the river. DOE stated that there is no groundwater discharge prior to the river.
- 7. NRC staff asked if an industrial site use with a farther offsite receptor had been evaluated. DOE stated that they are looking at DOE 435.1 scenarios only but under the CERCLA process various receptor locations are being evaluated.
- 8. NRC staff asked if there is a need to consider exposure scenarios involving criticality.
DOE stated that criticality is not a credible event and cited RPP 7475, Rev 8.
DOE stated that they are required to follow DOE standards which excludes radon flux from all pathways doses.
DOE-NRC 11-01-18 WMA C 2lPage WIR Teleconference Summary
Inadvertent Human Intruder (IHI)
- 10. The probability of intrusion was briefly discussed as NRC staff believed the discussion around intrusion probability lacked adequate basis. DOE stated they are not applying a probability approach.
- 11. NRC staff asked DOE to provide the basis that the intruder is an extremely unlikely scenario over the next 1,000 years and therefore below regulatory concern. DOE stated that is not below regulatory concern and they are attempting to provide the analysis suggested in NUREG-1854.
- 12. NRC staff asked DOE to describe why an intruder would put in a drinking water well but then not use any water from it in the dose assessment? DOE stated that the impacts to drinking water would be later after closure and the intruder dose is earlier after closure.
- 13. NRC staff asked DOE to provide the basis that grout is a deterrent to well drilling. DOE stated they would look for a report that describes regional drilling practices. NRC staff indicated that NUREG 1854 allows credit for tanks to provide a deterrent to well drilling for 500 years but for longer periods of time that protection becomes more speculative and a basis should be provided.
- 14. NRC staff asked DOE to confirm the dose calculation presented in Figure 9-15 of the PA document. DOE stated they confirmed Figure 9-15 is correct with a hand calculation.
- 15. NRC staff asked DOE to describe the depth to waste from the current land surface for the tanks, pipelines, and all ancillary equipment that is included within the scope of the assessment. DOE stated that the cover design is not complete but that the assumption is that at least 5 m of material will be over all components such that the excavation scenario is not credible.
DOE stated that radon flux had only been calculated at the land surface.
- 17. NRC staff mentioned that to put the intruder results in context, it may be useful to show the intruder risk from unplanned releases. DOE stated it is not a regulatory requirement for WIR.
Radionuclide Inventory (Ancillary Equipment)
- 18. NRC staff asked DOE about the differences in the number of pipelines identified in RPP-PLAN-47559, Rev. 0 and Rev 1. DOE stated that the method to count pipeline segments may be different but that the pipeline diameters and lengths as presented in Appendix A are the same in both documents.
DOE-NRC 11-01-18 WMA C 3lPage WIR Teleconference Summary
- 19. NRC staff asked what constitutes failed pipelines as referenced in RPP-PLAN-47559, Rev 1. DOE stated that failure is a pipeline that has leaked or has a breach of integrity which could be determined by a pressure test.
- 20. NRC staff asked DOE how many abandoned pipelines are within WMA C. DOE stated that all of the pipelines within WMA C are abandoned now or will be abandoned at closure.
- 21. NRC staff asked if 3 inches is the correct diameter for the V122 pipeline. DOE stated 3 inches is the correct diameter, and that most pipelines were 3 inches in diameter but that there were larger diameter pipelines in the WMA C including one 30-in pipeline.
DOE staff referred to Appendix A of RPP-PLAN-47559, Rev. 1.
- 22. NRC staff asked DOE to discuss what activities have been planned or undertaken to justify the assumption that the pipelines have 5% residual waste by volume. DOE stated that the lines were routinely flushed during operations and they may do additional work to verify waste volume during closure activities.
- 23. NRC staff asked DOE why is the 5% by volume assumption appropriate for partially plugged pipelines. DOE stated that lines that could be partially plugged (i.e., cascade lines) were assumed to be full (p. 3-154 of the PA document). Furthermore, the uncertainty in the waste activity and volume is included in the uncertainty analyses.
- 24. NRC staff asked why it is appropriate to assign the present-day average waste concentrations of isotopes to pipelines DOE stated that analytical packages are only available for post retrieval of tanks and that the values are chosen to represent an average of all the pipelines. DOE stated the rationale is presented on page 3-154 of the PA document.
- 25. NRC staff asked if DOE could provide a map showing the locations within WMA C of the eight assumed plugged cascade lines and the V122 pipeline. DOE indicated that they would provide a map.
- 26. NRC asked DOE to describe how the sludge volume was estimated for the tanks in 244-CR because some of the tanks were used for precipitation processes. DOE stated that the CR-vault volumes are from surface level measurements including sludge weight level and zip cord measurements and video assessment (RPP-RPT-24257).
- 27. NRC staff asked about the inventory in the 244-CR vault sump and what the sump is connected to. DOE indicated each of the four cells in the 244-CR vault has a concrete DOE-NRC 11-01-18 WMA C 4lPage WIR Teleconference Summary
sump with a volume of 45 gallons. The sump is not connected to another part of the system. It has to be pumped out with a submersible pump and the inventory is based on level measurements.
- 28. NRC staff referred to a picture of 241-C-151 diversion box from 1985 in RPP-RPT-46879, Rev. 2 (p. 3-8) and asked about one of the assumptions in Sec. 3.2.2.1 (p.
3-121) in the PA that states: It was assumed that the waste was or will be flushed from pits and diversion boxes DOE stated that the will be text should be removed from the PA. DOE stated that the diversion boxes will be inspected in the future using a camera. DOE stated they would provide document SD-RE-EV-001 which provides additional information on why DOE believes the diversion boxes currently contain no radionuclides except for radionuclides that have seeped into the concrete structure.
- 29. NRC staff asked DOE if it is assumed that diversion boxes will be flushed and have minimal inventory. DOE stated their assumption is that the diversion boxes have been flushed and that further evaluation will be conducted during closure activities.
- 30. NRC staff also asked why a 3-in diameter pipeline was used to represent the pipelines for the intruder scenario in the PA when the average pipeline diameter is up to 4.262 in.
DOE stated that the most common pipeline diameter was 3-in and therefore that was deemed most representative. However, if the average pipeline diameter value was chosen, it would only have a marginal effect. NRC staff asked from p. 9-9 of the PA document, what is the thickness of waste intercepted by borehole (Zws)? DOE assumes that the 5% waste in the pipelines has been mixed with clean soil before it was brought to the surface by the hypothetical driller so that it is 3-in thick.
- 31. NRC staff asked if the potential for leaks from the piping to the encasements but not to the environment had been assessed. DOE stated they dont know what is retained inside the encasements which are basically concrete troughs. DOE stated their best information is presented in the leak assessment report. They know some pipes have leaked into the encasements.
Action Items Item Date Action Status Number DOE-NRC 11-01-18 WMA C 5lPage WIR Teleconference Summary
9-6.3a 9-6-18 NRC to provide GoldSim run log to DOE Completed 9-25-18 9-6.3b 9-6-18 DOE to provide NRC with GoldSim model for 400,000 Completed year simulation 9-27-18 9-6.5 9-6-18 DOE to provide additional details regarding the scaling pending for other uranium isotopes 9-6.6 9-6-18 DOE to provide the aqueous relative permeability pending parameters assigned in STOMP model 9-6.8 9-6-18 DOE to provide map showing the location of node 69 in Completed relation to the tank footprint 10-25-18 9-6.9 9-6-18 DOE to provide a water budget table with inflow at the pending surface and inflow/outflow at the four aquifer boundaries 9-6.12 9-6-18 DOE to provide the simulated hydraulic heads from the pending STOMP model for the monitoring wells as seen in Fig. C-11, page C-22 9-6.14 9-6-18 Future presentation on Leapfrog geological model pending 9-6.15 9-6-18 DOE to check the discrepancy between 580 m3/d on PA pending
- p. C-8 and 730 m3/d on p. C-12.
10-2.10 10-2-18 DOE to send information on tank specific retrieval pending technology selection information 10-2.12 10-2-18 NRC to check information in NUREG 1854 on waste Completed classification criterion guidelines 11-13-18 10-2.a 10-2-18 DOE to check posting on website Completed 10-02-18 10-11.5 10-11-18 Item #5 from the 10-11-18 clarification call list will be Completed revisited next call when Bill McMahon is available. 10-25-18 10-11.6 10-11-18 DOE will generate a figure that represents the pipeline Completed source area used in the STOMP model. 10-25-18 10-11.7 10-11-18 DOE will review the discussion of Figure 7-16 on page 7- pending 24 of the PA document and make corrections as needed.
10-11.8 10-11-18 DOE will produce a revised figure showing the early Completed times (0 to 2000 years) for figures 7-15 and 7-16. 10-25-18 10-11.9 10-11-18 Item #9 from the 10-11-18 clarification call list will be Completed revisited next call when Bill McMahon is available. 10-25-18 10-11.11 10-11-18 Item #11 from the 10-11-18 clarification call list will be Completed revisited next call when Bill McMahon is available. 10-25-18 10-11.13 10-11-18 DOE to provide access to WRPS document RPP-ENV- Completed 334418 and CH2M Hill Hanford Group Inc. document 10-11-18 RPP-32681 10-11.15 10-11-18 DOE to provide NRC document that discusses how the pending unsaturated zone is effective at filtering colloids.
10-11.16 10-11-18 DOE to provide access to PNNL document PNNL-15226 Completed 10-11-18 10-11.18 10-11-18 DOE to provide access to Washington Closure Hanford Completed document WCH-520 10-11-18 10-11.20 10-11-18 Item #20 from the 10-11-18 clarification call list will be Completed revisited next call when Bill McMahon is available. 10-25-18 DOE-NRC 11-01-18 WMA C 6lPage WIR Teleconference Summary
10-11.21 10-11-18 NRC will locate the Sr-90 plume map it referenced in pending Item #21 from the 10-11-18 clarification call list.
10-11.31 10-11-18 DOE will address the typographic errors identified in pending Item #31 from the 10-11-18 clarification call list.
10-11.9a 10-25-18 DOE will correct the text on p. 8-80 related to the vertical pending extent of the modeled clastic dike 10-11.22 10-25-18 DOE to provide access to DOE/RL-2015-75 Completed 10-25-18 10-11.26 10-25-18 DOE to provide cross sections shown in Fig. 2.7 in pending PNNL-13024, and the cross-section G - G from Fig. B-1 in RPP-RPT-46088, Rev. 2 10-11.30 10-25-18 NRC staff to provide reference (PNNL-16407) to support Completed discussion of y unknown subsurface features 11-05-18 10-11.a 10-25-18 DOE to provide the most appropriate reference pending supporting the use of a no-flow bottom boundary in the 3D STOMP model 10-30.6 10-30-18 DOE to provide access to DOE/RL-2016-37 Completed 10-30-18 10-30.10 10-30-18 DOE to provide access to CERCLA documents that Completed relate to closure of the pipelines outside WMA C 11-9-18 10-30.15 10-30-18 DOE to provide access to RPP-RPT-55804 Completed 11-01-18 10-30.16 10-30-18 DOE to provide access to GRT4 GoldSim file Completed 11-9-18 10-30.25 10-30-18 DOE to search for references related to equipment that pending will remain in the tanks at closure 10-30.27 10-30-18 DOE to provide access to PNNL-15503 Rev 1 Completed 11-9-18 10-30.29 10-30-18 DOE to search for additional references related grout pending degradation 11-01.1 11-01-18 DOE to provide reference that supports land use Completed assumptions and the procedure for determining which 11-9-18 exposure scenarios will be evaluated 11-01.2 11-01-18 DOE to provide reference that supports the farmer pending scenario assumptions 11-01.13 11-01-18 DOE stated they would look for a report that describes pending regional drilling practices 11-01.25 11-01-18 DOE stated they would provide a map showing the eight Completed assumed plugged cascade lines and the V122 pipeline 11-9-18 11-01.26 11-01-18 DOE stated that would provide NRC access to RPT- Completed 24257 11-9-18 11-01.28 11-01-18 DOE stated that would provide NRC access to SD-RE- Completed EV-001 11-9-18 Acronyms and Abbreviations CPGW Central Plateau Groundwater CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of 1980 DOE-NRC 11-01-18 WMA C 7lPage WIR Teleconference Summary
DOE U.S. Department of Energy DOE-ORP U.S. Department of Energy Office of River Protection DOE-HQ U.S. Department of Energy Headquarters EHM equivalent homogeneous media NRC U.S. Nuclear Regulatory Commission PA performance assessment PNNL Pacific Northwest National Laboratory SST single-shell tank WIR waste incidental to reprocessing WMA waste management area WMA C Waste Management Area C WRPS Washington River Protection Solutions, LLC DOE-NRC 11-01-18 WMA C 8lPage WIR Teleconference Summary