ML21012A307

Responses to NRC Comments on the West Valley Demonstration Project Main Plant Process Building Decommissioning & Demolition Work Plan, Revision 4

ML21012A307
Person / Time
Site:	West Valley Demonstration Project
Issue date:	12/15/2020
From:	Bower B US Dept of Energy, West Valley Demonstration Project
To:	Marlayna Vaaler Doell Reactor Decommissioning Branch
Doell M
References
Download: ML21012A307 (14)

Text

Department of Energy Department of Energy Department of Energy Department of Energy West Valley Demonstration Project 10282 Rock Springs Road West Valley, NY 14171-9799 December 15, 2020 Ms. Marlayna Doell Reactor Decommissioning Branch Division of Decommissioning, Uranium Recovery, and Waste Programs Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission 22644 Hazel Lane Rapid City, SD 57702 Marlayna.Doell@nrc.gov

SUBJECT:

Responses to U.S. Nuclear Regulatory Commission (NRC) Comments on the West Valley Demonstration Project Main Plant Process Building Decommissioning &

Demolition Work Plan, WVDP-586, Revision 4 and NRCs Second Round of Comments on WVDP-579, Rev. 0, Vitrification Facility Air Emissions During Open-Air Demolition, Measured vs. Predicted

REFERENCES:

1) Letter (383265), A. M. Snyder to B. C. Bower, U.S. Department of Energy West Valley Demonstration Project Main Plant Process Building Decommissioning & Demolition Plan, WVDP-586, Revision 4, dated May 07, 2020 (Docket No. 05000201 (POOM-032)), dated September 22, 2020

2) Letter (383357), A. M. Snyder to B. C. Bower, Second Round of Comments on the U.S. Department of Energy West Valley Demonstration Projects Final Study Document: Vitrification Facility Air Emissions During Open-Air Demolition, Measured vs. Predicted, WVDP-579, Rev. 0 (Docket No. 05000201 (POOM-032)), dated April 27, 2020

Dear Ms. Doell:

The U.S. Department of Energy West Valley Demonstration Project (DOE-WVDP) is hereby providing the NRC with responses to NRCs comments on Revision 4 of the WVDP Main Plant Process Building (MPPB) Decommissioning & Demolition Work Plan provided in Reference 1.

The response to comment #8 includes responses to comments originally provided by NRC in Reference 2.

As indicated previously by DOE and stated by NRC in Reference 1, when final, DOE-WVDP will provide the NRC with the MPPB radionuclide inventory and analyses verifying the MPPB demolition will not exceed the National Emissions Standards for Hazardous Air Pollutants limits (Title 40 of the Code of Federal Register Part 61).

Ms. Marlayna Doell December 15, 2020 Please contact Moira N. Maloney of my staff at (716) 942-4255 if you have any questions, need additional information, or if you would like to schedule a conference call to discuss the attached.

Sincerely, Bryan C. Bower, Director West Valley Demonstration Project

Enclosure:

Responses to U.S. Nuclear Regulatory Commission (NRC) Comments on the West Valley Demonstration Project Main Plant Process Building Decommissioning &

Demolition Work Plan, WVDP-586, Revision 4 and NRCs Second Round of Comments on WVDP-579, Rev. 0, Vitrification Facility Air Emissions During Open-Air Demolition, Measured vs. Predicted ec: S. W. Chase, CHBWV, WV-10PLEX, w/enc.

T. D. Dogal, CHBWV, WV-PL17, w/enc.

D. P. Klenk, CHBWV, AC-RS, w/ enc.

E. A. Lowes, CHBWV, AC-RS, w/enc.

R. E. Steiner, CHBWV, AC-RS, w/enc.

K. P. Armstrong, DOE-EMCBC, Office of the Director, w/enc.

M. N. Maloney, DOE-WVDP, AC-DOE, w/enc.

D. W. Sullivan, DOE-WVDP, WV-DOE, w/enc.

A. M. Snyder, NRC, w/enc., Amy.Snyder@nrc.gov P. J. Bembia, NYSERDA, AC-NYS, w/enc.

BLM:383661 - 450.4

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NRC Staff Comments on Main Plant Process Building Decommissioning & Demolition (D&D) Plan, WVDP-586, Rev. 4 (West Valley Demonstration Project [WVDP] Responses in Italics)

1. Demolition Approach:

In Section 6.3, Demolition Approach, of the Main Plant Process Building Decommissioning & Demolition (MPPB) Plan (Plan), Rev. 3, the U.S Department of Energy - West Valley Demonstration Project (DOE-WVDP) states:

The overarching demolition approach and planned sequencing for the MPPB is to perform the demolition in a stepwise manner from the known radiologically "cleanest" areas (the outer support areas, interior support areas, and interior aisles) to those areas more impacted by prior processes (CPC [Chemical Process Cell], PMC [Process Mechanical Cell], LWC (Liquid Waste Cell), Extraction Cells, VWR

[Ventilation Wash Room], Hot Cells) and from top to bottom.

In Section 6.3, Demolition Approach, of the Plan, Rev. 4, DOE-WVDP states:

The overarching demolition approach for the MPPB is to perform the demolition in a stepwise manner based on structural evaluation from support areas (stairways, aisles, roofs) to main process areas (CPC, PMC, LWC, Extraction Cells, VWR, Hot Cells) and from top to bottom.

The rationale DOE-WVDP provides for this change remains the same as provided in Rev. 3 of the Plan:

This will minimize the potential for cross-contamination of facility areas, minimize migration of contamination and will reduce the time and resources associated with decontaminating equipment and materials from one area to another. This conceptual sequencing approach was successfully implemented during D&D of the WVDP 01-14 Building and during VF (Vitrification Facility) demolition.

As noted, in Attachment F, Main Plant Process Building (MPPB) Facility Demolition Schedule, the demolition sequencing has changed. However, as noted in Section 5.2, Deactivation Activities Remaining, [D]econtamination activities will continue to progress until such time that the structure meets prescribed limits for open air demolition.

Actions such as painting surfaces and using a water curtain are being used to keep exposure during demolition ALARA (as-low-as reasonably-achievable). Does the sequence of demolition influence exposure?

WVDP Response:

The sequence is related to maximizing contamination control during demolition, as opposed to minimizing dose; the basis for the change in sequence is more fully described in the below response. Based upon use of the U.S.

Environmental Protection Agency (EPA)-approved alternative method the projected total dose to the Maximally Exposed Offsite Individual (MEOSI) is anticipated to be well under 0.1 mrem over the course of the entire MPPB demolition, and therefore there is no particular required sequence necessary to ensure public protection. DOE-WVDP is in the process of finalizing the National Emission Standards for Hazardous Air Pollutants (NESHAP) dose calculation and plans on providing it to NRC, along with supporting characterization and modeling information, in the near future.

The U.S. Nuclear Regulatory Commission (NRC) staff seeks further clarification on the reason and technical basis for the change in demolition approach and sequencing. Specifically, are there any impacts on radiological health and safety of worker and public, to include waste management or water management as a result of the change in approach and sequencing? If so, please elaborate.

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WVDP Response:

The primary reason and technical basis for the change in demolition approach and sequencing is to minimize the size of the active demolition and bermed area, which reduces the volume of contaminated demolition water to be managed.

This sequence and phased demolition approach also allows for the incorporation of structural features of the cell(s) being demolished during each phase into smaller containment areas, resulting in opportunities for more efficient water management during demolition. The sequencing approach, which minimizes the size of the active demolition area, also reduces overall equipment movement and limits the restaging of equipment during and between phases of building demolition, which limits the potential spread of contamination. Therefore, there are benefits to this revised sequencing approach from both a water management and contamination control perspective, and it is also supportive of waste minimization.

The sequencing doesnt directly impact waste management of demolition debris, but lessons learned will be applied to certain aspects of waste management such as minimizing the time debris sits prior to packaging and placing the waste containers close to the debris pile for loading. The sequencing supports a logical flow of waste containers into and out of the demolition area for packaging, handling, and loading for shipment. As demolition progresses, waste containers will be moved to and from the debris pile without interference from the staged demolition equipment and remaining portions of the building. These approaches further minimize the potential for public impacts.

2. Characterization:

2. a. Section 1.3, Scope, states that the MPPB [D&D Plan] contains, among other things, a summary of characterization information and an overview of the management approach. Although DOE-WVDP describes its characterization approach for accessible areas, it is unclear how DOE-WVDP plans to address areas or items that need special handling, such as contaminated piping that will remain before demolition begins and will be removed during demolition.

WVDP Response:

All areas of the plant have been surveyed, including items such as tanks and process piping. All process piping has been identified based on historical facility knowledge and engineering drawings and included in the Material-at-Risk (MAR). Such items have been isolated and clearly identified for removal during the demolition process. Examples include plans for:

Removing the Lower Extraction Aisle (LXA) ventilation duct sections prior to roof demolition and orienting the sections with the hot side down in the waste package; Requiring removal of certain cell liners intact for immediate packaging; and Removal of certain process lines to be segregated and packaged in a specialty container.

2.b. In Section 3.1, Radiological Characterization, DOE-WVDP states:

Surfaces of the facility will generally be painted (i.e., fixative applied) before MPPB demolition to reduce the remaining loose activity levels. Data collected (emphasis added) are utilized for dose modeling to support demolition sequencing and limits (i.e., maximum number of square feet in a given area that can be removed or demolished in a given time period).

Characterization data will also be used to model potential dose to onsite workers (i.e., using AERMOD, air dispersion modeling system and WVDP-593, Air Monitoring of Radioactive Releases During the Uncontained Demolition of the West Valley Vitrification Facility) and the public (i.e. the maximally exposed off-site individual [MEOSI] using CAP88 dose modeling software).

It is unclear how does DOE-WVDP plans to address radiological characterization and dose modeling before demolition of the sealed rooms, any other parts of the MPPB that are not accessible for data collection for radiological characterization (inventory) and dose modeling.

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WVDP Response:

Radiological survey information has been obtained from all areas and this information has been used in the dose evaluations. Depending on the area, survey information is collected either remotely or by Radiological Control personnel. Survey information is typically collected by performing a smear survey for alpha and beta/gamma radioactivity and/or performing direct readings for alpha and/or beta/gamma depending on background or surface condition and in some cases sampling of piping and surfaces. Survey information is gathered for each cell, with the survey concentration (disintegrations per minute (dpm)/100 square centimeters) applied over the applicable surface area and scaled to the isotopic distribution. The results are summed and a total MAR in curies is determined.

2. c. Further, in Section 7.1.2, Radiological Characterization, DOE-WVDP states: Waste package characterizations will utilize the same unit-by-unit source term estimates being prepared to substantiate the acceptability for open-air demolition. The disposition of each unit/component will be tracked to individual waste packages and summed to provide the total radioactivity content of a given package.

Please clarify DOE-WVDPs strategy for inaccessible areas and items that need special handling during demolition to determine the maximum number of square feet in a given area that can be removed or demolished in a given time period to protect worker and public health and safety during demolition.

WVDP Response:

All areas have been accessed for radiological survey data, either directly or remotely and the results have been included in the analyses that support open air demolition. The time constraints refer to minimum demolition times for each area based on radioactivity levels and limiting the amount of overall radioactive surfaces demolished during a shift. Demolition waste or debris requiring specialized management has been identified; specific examples are provided in the response to question number 2a.

3. Waste Generation:

Section 6.1 states: The following general performance criteria will be incorporated into the work scope for the MPPB D&D:

during the decommissioning and demolition work, CHBWV will minimize the generation of difficult to dispose of waste streams such as transuranic (TRU) and mixed-TRU waste and mixed low-level waste (MLLW);

Clarify whether DOE-WVDP expects the generation and disposal of all the above-mentioned waste streams. If so, please elaborate on the approach to manage such waste streams and identify the estimated waste quantities the MPPB decommissioning.

WVDP Response:

TRU and MTRU are not expected to be generated during demolition. However, there will be a significant amount of MLLW encountered during demolition that was not accessible during deactivation. These items are included on the attached table and include: leaded shield windows, a large sample station with lead counterweights, electrical panels, and several areas with lead shielding.

To minimize the potential of mixing MLLW with LLW, CHBWV developed a list of items that must be segregated and packaged separately during demolition. The areas to be demolished each day will be reviewed at the daily brief and the items that must be segregated and packaged separately will be identified.

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4. Waste Debris Controls Strategy:

In reviewing the Hanford Plutonium Finishing Plant corrective action report, controls were put in place for the project after December 2017 to better manage waste. Strategies or guidance for the movement of materials that needed special handling during demolition; waste segmentation; waste loading, and staging were put in place. Also, requirements for not allowing waste piles to accumulate were instituted. In Section 6.0, of the Rev. 4 of the Plan, DOE-WVDP added the following lessons learned that it stated will be factored into the planning of the MPPB demolition:

control of debris piles, including waste loading speed, less aggressive waste conditioning, and use of dust suppression; preparing an adequate supply of waste containers ready for loading; Section 6.1, of the Plan states that [D]ebris piles will be sprayed with a suppressant at the end of each day or more frequently and that the [A]pplication of additional fixative will be considered for demolition materials/debris that require further processing on the ground or are awaiting packaging into waste containers. Further, the Plan briefly mentions staging of waste, but there is limited information on the strategy on how the demolition waste debris and waste packages will be staged or move for segmentation or material added to the already existing waste piles located on the ground.

4a. The NRC staff seeks further elaboration on strategy for staging demolition debris and loading.

WVDP Response Based on lessons learned, the approach is to keep debris piles close to the demolition area, bring the waste packages close to the pile to be filled, and minimize the time debris sits prior to packaging. There is no planned segmentation for radiological waste since all debris has been characterized to be low-level, and the movement of debris will be minimized. Some material will be sized reduced for packaging close to the debris pile with active dust suppression.

The sequencing supports a logical flow of waste containers into and out of the demolition area for packaging, handling, and loading for shipment.

4b. What is DOEs strategy for how long that demolition debris should be on the ground accumulating before it is packaged, regardless of whether additional fixative is applied.

WVDP Response Controls have been put in place requiring that Low Level debris (<4.81E+06 dpm/100 square centimeters Alpha average activity based on pre-demolition radiological characterization of surfaces within the given areas/cells) will be packaged within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. For special circumstances, approval by the Radiation Safety Manager for additional time for pile removal may be granted. Such approval would include specific, prescribed controls based on the conditions being addressed. Examples of prescribed controls include additional fixative application, more frequent radiation surveys, etc. Higher activity piles (4.81E+06 dpm/100 square centimeters or greater) have protected assumptions and require packaging within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and no additional time for pile removal may be granted.

4c. Please explain the guidance or criteria for when additional fixative should be applied to the debris that is on the ground, besides at the end of the day.

WVDP Response The planned approach is to apply fixative to a remaining debris pile at the end of the day or if reapplication is needed based on weather conditions and/or when a pile is observed to be drying. As noted above, additional application could also be an additional control if a low-level pile cannot be packaged in 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

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4d. During the Vitrification Facility demolition, DOE-WVDP announced that it completed demolition and then addressed the remaining demolition debris. Please elaborate whether this will be the same strategy for the more contaminated MPPB demolition.

WVDP Response:

See response to 4b.

5. Monitoring:

Will there be multiple measurements downwind to detect dispersion of dusts? For the MPPB demolition this approach may be more critical than the Vitrification Facility demolition since the source term is more risk significant and could become airborne. At the Hanford Plutonium Finishing Plant demolition, a metal plate system was used. Does DOE plan to use such an approach for the MPPB D&D?

WVDP Response:

Plans for monitoring include 15+ air monitoring and sampling locations that will be operating during all demolition activities and positioned based on air modeling and personnel location. The air monitors will present data in real time.

All filters will be saved and counted for official long lived activity after 7 days. There will be a minimum of 12 deposition metal plates, similar to those used at Hanford Plutonium Finishing Plant and Vitrification Facility demolition, and 18 other identified surfaces, and planned Buffer Area perimeter deposition monitoring locations. The metal plates will be surveyed at least 3 times per shift.

16 Ambient air monitoring stations located around the perimeter of the WVDP continuously monitor for airborne radioactivity and confirm protection of the public (i.e., regulatory limits are maintained).

6. Work Control Strategy.

6 a. Based on the Hanford Plutonium Finishing Plant Demolition Resumption Expert Panel Final Report, it appears prudent for the MPPB Work Instruction Packages (WIPs) to include specific stop work requirements, based on the modeling insights that include weather, i.e., wind speed, direction, weather forecasts, precipitation. Also, explain whether management will be involved in making such stop work decisions based on weather and how they would be aware of all meteorological issues.

WVDP Response:

Specific stop work requirements will be identified, to include weather-related restrictions such as those related to wind speeds and precipitation. Management is involved in all stop work decisions including weather. Forecasted weather conditions are discussed daily during the morning Safety Assessment Center meeting report and are monitored throughout the work shift.

6b. While it appears that there has been significant source reduction based on the pre-demolition activity updates in Rev. 4 of the Plan, NRC staff suggests that DOE-WVDP address the strategy or commitments for:

The type of surveys needed and what was done and will be done to control potential hide-out of high levels of contamination in interstitial gaps: floor to floor, floor to wall, wall to wall, wall to ceiling given that the MPPB is highly compartmentalized.

Radiological inventory strategy for sealed rooms.

Based on the processes performed in the MBPP (spent fuel chopping) and the use of fixatives, once demolition is being performed, there is the possibility for hot particles. The Radiation Program should include surveys geared to hot particle detection on workers and address surveys for the lands once the

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waste debris is removed.

WVDP Response:

All areas of the MPPB (including the sealed rooms) have been surveyed and historical information was used to identify locations that were not obvious initially. The radiological survey information that has been obtained from all areas has been used in dose evaluations. Depending on the area, survey information is collected either remotely or by Radiological Control personnel. Survey information is typically collected by performing a smear survey for alpha and beta/gamma radioactivity and/or performing direct readings for alpha and/or beta/gamma depending on background or surface condition and in some cases sampling of piping and surfaces. Survey information is gathered for each cell, with the survey concentration (dpm/100 square centimeters) applied over the applicable surface area and scaled to the isotopic distribution. The results are summed and a total MAR in curies is determined.

Fixatives have been used inside process piping and will be used on any new surface exposed. The fixative was selected to minimize resuspension and hot particle mobility.

There will be a minimum of 12 deposition metal plates similar to those used at Hanford Plutonium Finishing Plant and Vitrification Facility Demolition, and 18 other identified surfaces, and planned Buffer Area perimeter deposition monitoring. The metal plates will be surveyed at least 3 times per shift.

7. As a part of the lessons learned from the Vitrification Facility Demolition, will DOE-WVDP comment on how efficient the water collection system was during demolition? How much water was recovered compared to the amount used? Has DOE-WVDP enhanced its water collection strategy and berming approach as compared to that used for the Vitrification Facility demolition.

WVDP Response:

Due to precipitation that occurred during Vitrification Facility demolition and the large size of the bermed area, much more water was collected than was used for dust suppression. As a result of the lessons learned, the approach was changed to be more efficient during MPPB demolition. The MPPB demolition approach minimizes the size of the active demolition and bermed area, which reduces the volume of contaminated demolition water to be managed.

Additionally, a water management plan has been developed, utilizing a series of tanks including separate evaluation tanks and holding tanks, depending on characterization results, to provide for efficient management and disposition of the collected water.

8. Dose Modeling:

In reviewing Rev. 4 of the Work Plan, the NRC staffs questions submitted on April 27, 2020 (Agencywide Documents Access and Management System Accession No. ML20115E497), as related to the MPPB demolition still stand. The NRC staff would like to understand how its April 27, 2020, comments on dose modeling as related to the MPPB were addressed and whether there were any changes to the Plan as a result of the NRC staff comments.

WVDP Response:

DOE-WVDP is in the process of finalizing the NESHAPs dose calculation and plans on providing it to NRC, along with supporting characterization and modeling information. At that point, DOE-WVDP believes it would be most productive to arrange a technical dialogue among modeling subject matter experts to address specific input. The below provides excerpts from the April 27, 2020 NRC letter and associated initial responses.

The approach to use the 0.02 DAC appears reasonable. Could DOE confirm what controls will be in place and at what level action will be taken to address issues associated with greater than expected air concentrations and dose to workers and members of the public during demolition of the MPPB? For example, alerts were established prior to a stop work established at 3 derived air concentration (DAC)-hour per day for the vitrification facility demolition.

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WVDP Response:

On the E-CAMs the same two alert levels and one alarm level that were used and proven effective during Vitrification Facility demolition will be in place for MPPB demolition.

Additionally, action levels of 0.02 DAC at the security fence and activity on deposition mats of 20 dpm/100 cm2 alpha and 1000 dpm/100 cm2 beta-gamma have also been proposed for the MPPB demolition. How often will the deposition mats be monitored?

WVDP Response:

Plans for monitoring include 15+ air monitoring and sampling locations that will be operating during all demolition activities and positioned based on air modeling and personnel location. The air monitors will present data in real time.

All filters will be saved and counted for official long lived activity after 7 days. There will be a minimum of 12 deposition metal plates, similar to those used at Hanford Plutonium Finishing Plant and Vitrification Facility demolition, and 18 other identified surfaces, and planned Buffer Area perimeter deposition monitoring locations. The metal plates will be surveyed at least 3 times a shift.

While the risk from C-14, I-129, and Tc-99 may be low, some form of consideration of dose from these radionuclides appears necessary to make that determination given they are listed as key radionuclides. For the MPPB AERMOD, please address how the dose from C-14, I-29, and Tc-99 were considered if eliminated from the models.

WVDP Response:

Tc-99 and I-129 isotopes were included in the latest air dispersion modeling for MPPB open air demolition using AERMOD. The percentage of total dose contribution from I-129 is approximately 0.00001% and approximately 0.001% from Tc-99. C-14 was not included because it has been previously determined to not be a significant dose contributor and it is not included in routine site monitoring.

Clarify if all radionuclides are treated as particulates. Specifically, clarify how Cs-137 and other radionuclides that are assumed to be volatilized during hot cutting activities are treated in the modeling (i.e., as gases and/or particulates).

Also, confirm that particle size and deposition are not considered in the modeling and how this influences the results of the validation study (e.g., location of samplers) and estimation of dose in general (e.g., impact on dose estimates for external radiation and inhalation exposure).

WVDP Response:

As a result of lessons learned from Vitrification Facility demolition, the oxylance torch will not be used during MPPB Demolition due to the extreme high heat and volatility. Any hot cutting by alternate means (e.g., oxygen-gasoline, oxygen-acetylene, etc., which cut at lower temperatures) will be reviewed and incorporated in off-site dose calculations as appropriate and is required to be reviewed and approved by Radiological Engineering. Radiological Engineering has identified maximum contamination levels for materials to be cut. All particles are considered within the respirable range. Air monitoring and sampling will take place during hot cutting activities giving real time results.

For CAP88 modelling (NESHAP compliance) Cs-137 is considered a particulate. Although upon cutting it might be volatilized, it is assumed to cool fairly rapidly and become a particulate. Cs-137 is sampled for at the ambient sampling locations as a particulate (on glass fiber filters) as are all other radionuclides (except iodine, which is collected on charcoal).

Suggest providing figures of modeled plume distributions to support general predictive capability of the model in comparison to measured data. Air monitoring data collected within and outside the 30-m contamination area boundary, as well as data collected from deposition mats could be used for a qualitative comparison to assess the predictive capability of the model to simulate atmospheric transport of radioactivity from the demolition sources to downwind

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locations.

AERMOD can consider building wake effects so the relevance of samplers being subject to building wake affects as an argument for not including these samplers does not appear to be compelling. Further, it is unclear if meteorological data that was used to determine the validation study sampling locations are representative of conditions during demolition. For example, if most demolition activities occurred during the day3 and meteorological data are collected over day and night time hours, then the wind rose data may not be representative of the hours during which most of the demolition activities occur. Additionally, meteorological towers are typically located in areas free of obstructions.

Because the wind direction near the demolition site may be influenced by nearby obstructions, the wind rose data from the onsite meteorological tower may not be reflective of conditions at the demolition site.

Additionally, particle and gaseous deposition does not appear to be considered in the modeling, although particle size and chemical form are expected to influence atmospheric transport. Information on the physical and chemical form of the radioactivity would have been helpful in siting the validation study samplers.

Also depending on the release height of sources, building wake effects, and buoyancy effects (e.g., from hot cutting activities), the locations of the samplers may not have been optimally located.

While AERMOD modeling may be conservative with respect to dose, the purpose of a validation study that uses actual monitoring data to make parameter adjustments to match the data inherently presumes that the model is realistically simulating atmospheric transport. Additional information would be needed to support the changes to air release fractions for hydraulic hammering and other parameters (moisture content for debris piles and physical state factor for hot cutting) to ensure that the AERMOD estimated air concentrations are reasonably conservative considering the significant uncertainty in the model and limited data provided to support the modeling adjustments. With respect to addressing hydraulic hammering and other parameters noted above for the MPPB demolition, the NRC staff suggest DOE evaluate these aspects for the AERMOD model used for the MPPB demolition. NRC anticipates that DOE will execute its plan, as identified in the MPPB Work Plan on page 60-61 and 57 to ensure that workers and members of the public will be protected during open air demolition due to the large safety margin and controls that will be in place during demolition of the MPPB.

WVDP Response:

DOE-WVDP appreciates NRCs insights and suggestions and will evaluate the NRC staff suggestions. Based on the Vitrification Facility demolition and associated air monitoring results, the modeling was demonstrated to be conservative. As MPPB demolition proceeds, monitoring data will be evaluated in this regard. DOE-WVDP intends to execute the plan described in the MPPB Demolition Work Plan and is available to discuss this further with NRC after providing the characterization and modeling information.

NRC notes that the changes to the model parameters for hot cutting should be demonstrably conservative if the uncertainty in model predictions is significant and cannot be reduced (the updated modeling results were sometimes slightly lower and slightly higher than positive detections at offsite sampling locations during hot cutting activities and therefore not clearly conservative). For example, it appears that the modeling only considers particulate release (see comment 1.b.1 and 1.b.2 which seeks clarification on treatment of volatile radionuclides) although radionuclides are assumed to be volatilized during hot cutting activities. The degree to which the released fraction is volatilized, the extent to which this radioactivity is transported as a gas, and the point at which this material condenses back to form solid particulates are unknown and do not appear to be considered in the modeling. Therefore, comparison of modeling results with particulate measurements at significant downwind distances does not appear to be enough to assess the adequacy of the predictive capability of the model.

WVDP Response:

As a result of lessons learned from Vitrification Facility demolition, the oxylance torch will not be used during MPPB Demolition due to the extreme high heat and volatility. Any hot cutting by alternate means (e.g., oxygen-gasoline, oxygen-acetylene, etc., which cut at lower temperatures) will be reviewed and incorporated in off-site dose modeling

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as appropriate, and is required to be reviewed and approved by Radiological Engineering. Radiological Engineering has identified maximum contamination levels for materials to be cut. All particles are considered within the respirable range. Air monitoring and sampling will take place during hot cutting activities giving real time results.

In previous documentation, CAP88 was stated to be used to estimate doses to offsite members of the public in determining whether the facility was open air demolition ready. While offsite data may be used to calculate dose for the purpose of the ASER, please clarify the use of CAP88 to estimate offsite doses prior to building demolition for the Vitrification Facility and Main Plant Process Building.

WVDP Response:

The use of CAP88 or AIRDOS-PC is required in NESHAP regulations (specifically in 40CFR61.93(a)) to determine compliance with the standard (or thresholds originating from it), both retrospectively and prospectively. Its use is required for NESHAP compliance unless EPA has granted prior approval to use an alternative procedure. The WVDP is using CAP88 in accordance with resuspension factors in the alternative methodology prepared by the WVDP and approved by the U.S. EPA under 40 CFR 61.96(b).

WD:2020:1087 10 Mixed Low-Level Waste from MPPB Demolition EQUIPMENT Location Container Size Drain line slip joints Solvent Storage Terrace (SST)/ Tank 7D-5 Area 20 cubic yard (cuyd)-

Intermodal Container (IMC) or 8'x5'x5' Bag Electrical panels SST/ Tank 7D-5 Area B25 (box) (6'x4'x4') or Drum Lighting SST/7D-5 Area 20 cuyd IMC or 8'x5'x5' Bag Lighting Extraction Chemical Room (XCR)

B25 (6'x4'x4') or Drum Artisan Arm controls XCR B25 (6'x4'x4') or Drum Lead shielding XCR B25 (6'x4'x4')

Lead blankets XCR B25 (6'x4'x4')

Lead shielding XCR B25 (6'x4'x4')

Drain lines XCR 20 cuyd IMC or 8'x5'x5' Bag Lead Shielding XCR-Pulse Equipment Aisle (PEA)

B25 (6'x4'x4')

Lead Sheets on South Wall South West Stairs B25 (6'x4'x4')

Drain Slip Joints Off-Gas Operating Aisle (OGOA)

B25 (6'x4'x4')

Residual Electrical OGOA 20 cuyd IMC or 8'x5'x5' Bag Pipe Shielding South Stairs B25 (6'x4'x4')

Lead Shielding - sheet South Stairs @ Upper Extraction Aisle (UXA)

B25 (6'x4'x4')

Shield Window Off-Gas Blower Room (OGBR) 3'x3'x3' Custom designed bag Lead Curtain Off-Gas Cell (OGC)

B25 (6'x4'x4')

Raw Lead Sheets Ventilation Exhaust Cell (VEC)

B25 (6'x4'x4')

SGN System Process Chemical Room (PCR) East Wall B25 (6'x4'x4')

Shield windows Chemical Process Cell (CPC)

Custom designed bag or box Shield windows CPC Custom designed bag or box Shield windows CPC Custom designed bag or box

WD:2020:1087 11 EQUIPMENT Location Container Size Lead sheet North side of Control Room behind Ventilation Exhaust Cell (VEC) duct B25 (6'x4'x4')

Shield Windows Sample Storage Cell (SSC) 5'x3'x4' Custom designed bag Shield Windows SSC 5'x3'x4' Custom designed bag Shield Windows SSC 5'x3'x4' Custom designed bag Lead packing in drains UXA 20 cuyd IMC or 8'x5'x5' Bag 1C Sampler Shield Block Arrangement &

Cart/Ball Manipulator CPC; Chemical Operating Aisle (COA) 20 cuyd IMC or 8'x5'x5' Bag Light ballasts Mechanical Operating Aisle (MOA)

B25 (6'x4'x4')

or Drum Shield Windows Sample Cell 4'x4'x4' Custom designed bag Shield Windows Hot Cell (HC)1 6'x4'x4' Custom designed bag Shield Windows HC2 6'x4'x4' Custom designed bag Shield Windows HC3 6'x4'x4' Custom designed bag Shield Windows HC4 6'x4'x4' Custom designed bag Shield Windows HC5 6'x4'x4' Custom designed bag Lead Shielding - sheet Analytical Aisle (ANA)

Lab flooring B25 (6'x4'x4')

Lead Shielding - sheet ANA; surrounding ventilation duct B25 (6'x4'x4')

Lead Pigs ANA B25 (6'x4'x4')

Lead packing in drain lines ANA 20 cuyd IMC or 8'x5'x5' Bag Lead shielding sheet Ram Equipment Room (RER)

B25 (6'x4'x4')

e-Waste East Stair Crows Nest B25 (6'x4'x4')

or Drum Mercury Abatement Trap Uranium Load Out (ULO) B25 (6'x4'x4')

WD:2020:1087 12 EQUIPMENT Location Container Size Mercury Abatement Sample Tank ULO B25 (6'x4'x4')

Pipe Rad Monitor ULO/Mezzanine B25 (6'x4'x4')

Shield windows CPC Custom designed bag or box Lighting Chemical Crane Room (CCR) 20 cuyd IMC or 8'x5'x5' Bag Shield Window CCR Custom designed bag 5'x4'x3' Shield Window Scrap Removal Room (SRR) 4'x4'x4' Custom designed bag Shield windows Equipment Decontamination Room Viewing Aisle (EDRVA)

B25 (6'x4'x4')

Crane electrical cabinets EDRVA B25 (6'x4'x4')

Lead Blankets Equipment Decontamination Room (EDR)

B25 (6'x4'x4')

Shield Windows Process Mechanical Cell (PMC) 7'x7'x7' Custom designed bag Shield Windows PMC 7'x7'x7' Custom designed bag Shield Windows PMC 7'x7'x7' Custom designed bag Shield Windows PMC 7'x7'x7' Custom designed bag Shield Windows PMC 5'x6'x6' Custom designed bag Lead Pigs Mass Spec Lab B25 (6'x4'x4')

Transformers East Mechanical Operating Aisle (EMOA)

B25 (6'x4'x4') or Drum Shield Windows PMC 5'x6'x6' Custom designed bag Shield Window PMC Crane Room Enclosure (PMCRE) 4'x3'x1' Custom designed bag Shield Window PMCRE 4'x3'x1' Custom designed bag Shield Window PMC Crane Room (PMCR) North Stairs 4'x3'x2' Custom designed bag Shield Window PMCR Custom designed bag Manipulator Repair Room (MRR) - lead glass North Mechanical Operating Aisle (NMOA)

Intermodal or Lift Liner Bag Lead shielding -under MRR glass NMOA Intermodal or Lift Liner Bag