ML18092A056
| ML18092A056 | |
| Person / Time | |
|---|---|
| Site: | West Valley Demonstration Project, P00M-032 |
| Issue date: | 02/05/2018 |
| From: | Bower B US Dept of Energy, West Valley Demonstration Project |
| To: | Amy Snyder NRC/NMSS/DDUWP/MDB |
| AMSnyder NMSS/DUWP/MDB 415.6822 T5D48 | |
| References | |
| Download: ML18092A056 (10) | |
Text
I Department of Energy West Valley Demonstration Project 10282 Rock Springs Road West Valley, NY 14171-9799 February 5, 2018 Amy Snyder, Senior Project Manager Materials Decommissioning Branch Division of Decommissioning, Uranium Recovery, and Waste Programs Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Two White Flint North 11545 Rockville Pike Rockvilie, MD 20852-2738
SUBJECT:
U.S. Department of Energy West Valley Demonstration Project (DOE-WVDP)
Responses to U.S. Nuclear Regulatory Commission (NRC) Comments on DOE-WVDP Main Plant Process Building (MPPB) Decommissioning
&Demolition (D&D) Plan, WVDP-586, Rev. 1, dated February 27, 2017
REFERENCE:
Letter (374925), A. Snyder to B. C. Bower, "U.S. Department of Energy West Valley Demonstration Project Main Plant Process Building Decommissioning
& Demolition Plan, WVDP-586, Revision 1 (Docket No. 05000201 (POOM-0032))," dated September 28, 2017.
Dear Ms. Snyder:
DOE-WVDP responses to the NRC comments on the MPPB D&D Plan are provided in the enclosed table. After all comments have been resolved to NRC's satisfaction, the WVDP MPPB D&D Plan (WVDP-586) will be finalized and a copy will be provided to you. Our goal is to have the Plan issued in March 2018.Please contact Moira Maloney of my staff at (716) 942-4255 if you have any questions or need additional time for your review.Sincerely, C. Bower, Director West Valley Demonstration Project
Enclosure:
Comment and Response Table for the NRC Comments on the WVDP MPPB D&D Plan cc: See Page 2 JF:377509-450.4 Ms. Amy Snyder February 5, 2018 cc: S. W. Chase, CHBWV, WV-IOPLEX, w/enc.T. D. Dogai, CHBWV, WV-IOPLEX, w/enc.D. P. Klenk, CHBWV, WV-IOPLEX, w/enc.R. E. Steiner, CHBWV, WV-PL6, w/enc.M. N. Maloney, DOE-WVDP, AC-DOE, w/enc.Z. Z. Zadins, DOE-WVDP, AC-DOE, w/enc.A. Snyder, NRC, w/enc., amv.snvder@,nrc.gov P. Bembia, NYSERDA, AC-NYS, w/enc.JF:377509-450.4 U.S. NUCLEAR REGULATORY COMMISSION STAFF COMMENTS ON WVDP MAIN PLANT PROCESS BUILDING DECOMMISSIONING
& DEMOLITION PLAN, REVISION 1. WVDP-586 Comment Number NBC Comment WVDP Response 1)Page 15 of 94"Table 2 shows an example of radioactivity levels for several areas based on the characterization data. Data collected 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)....
Radiological surveys and samples continue to be collected to characterize and make a determination that each area is ready for demolition." Comment 1: Please clarify the removable fraction for the surficial concentrations listed in Table 2. Please clarify what efforts were made to determine If the materials are volumetrically contaminated (e.g., provide additional detail on sampling and measurement methods).1. The activity levels identified in Table 2 are total activity/1 OOcm^ (fixed plus removable).
Surfaces of the facility are being painted (i.e., fixative applied) before MPPB demolition to bring the remaining loose activity levels down below 2,000 dpm/IOOcm^
Alpha and 100,000 dpm/1 OOcm^ beta-gamma.
- 2. Due to the condition of the surfaces in many locations, such as: original paint intact, stainless steel liner present, etc., the activity is generally considered to be present on the surface. Many areas were sampled by drilling or coring into the concrete surface approximately three-quarters of an inch, where the activity stopped at most locations.
These samples were screened with field instruments and then sent to an onsite laboratory for isotopic analysis.
For some areas where multiple layers of grout had been placed over the years for shielding, full-thickness cores were taken through to the ceiling of the area below and the cores were analyzed in a laboratory for total activity.2)Page 15 of 94"Also, grout will be placed in below-grade portions of the MPPB and on the 100 foot plant elevation floor (i.e., ground level) prior to demolition, as necessary to reduce the radiological dose to workers and provide a protective barrier during demolition.
Additional material such as gravel may also be used to protect the underlying surfaces.""Information on residual radioactivity levels of these surfaces will be collected prior to grouting, but this radioactivity is not included in the dose modeling to support open air demolition since the surfaces will not be disturbed during this demolition." Comment 2: At this point in the document, it is unclear what portions of the MPPB will remain at the end of the demolition.
Clarify the intended disposition of the grouted surfaces; and whether the grouted surfaces will remain or will be removed during this or future demolitions to provide support for the statement that the inventory on the surfaces will not be included In dose modeling because the surfaces will not be disturbed during demolition.
Clarify what is meant by providing a "protective barrier" (i.e., the grout serves as a barrier to prevent damage to below-grade or 100 foot plant elevation surfaces from demolition of above-grade portions of the MPPB, and/or to prevent release of radioactivity).
The scope of work for this phase of demolition (Phase 1 A) includes removal of the MPPB to the first floor slab (nominal 100 +/- 3-ft reference elevation).
The first floor slab and stub walls are intended to remain intact to help control storm water and to prevent surface water infiltration into the subsurface cells and soil.The grouted surfaces and additional material serve as a protective barrier to prevent damage to the first floor slab and below-grade structures and control the potential for contamination to migrate from these surfaces during and following Phase 1A demolition.
All parts of the MPPB slab and below-grade structures/foundations will be removed during the next phase of demolition (Phase IB).The first sentence referenced will be revised as follows; "Also, grout will be placed in below-grade portions of the MPPB and on the 100 foot plant elevation floor (i.e., ground level) prior to demolition, as necessary to reduce the radiological dose to workers and provide a protective barrier to prevent damage to the first floor slab and below-grade structures during and following demolition." The following sentence will be added at the end of the referenced paragraph on page 15: 'The below-grade portions and remaining grouted, ground-level surfaces of the MPPB will be removed during a subsequent phase of demolition." The attached figure showing a plan view following demolition will also be added WD:2018:0081 to the Plan to compliment Figure 25 which shows a cross-sectional view.3)Page 15 of 94'Table 3 shows the radioactivity levels in two of the areas of the MPPB (Process Sample Cell-2 and Extraction Cell-2) where data have been collected and the determination made that the areas are ready for demolition.
This Is an example of the data that will be collected for the various areas of the MPPB and used to determine that the overall building Is ready for demolition with the implementation of appropriate radiological controls.
Calculations using AERMOD and the radioactivity levels for a given area are performed to show that the remaining activity levels are below the maximum that can be left behind to comply with worker dose limits." Comment 3: Data in Table 3 appear to be based on CS'137 concentrations and the use of scaling factors. Please clarify the basis for and expected error associated with use of scaling factors.The method for estimating activity in Main Plant areas was predicated on the nature of contamination In the area under consideration.
In areas with low gamma background radiation and In which contamination had not been previously fixed through the use of paint or other fixatives, direct gross alpha measurements were used to quantify the area! concentration of alpha contamination in the cell. For areas with elevated background radiation or in areas in which fixative had been applied, surface beta/gamma dose rates were used to infer Cs-137 contamination levels. In both methods, estimates of indicator parameters (Am-241 in the former and Cs-137 in the latter) were correlated to the concentration of other nuclides through the use of scaling factors derived from historical sampling results. Finally, areas exhibiting very high background radiation fields were characterized through the use of sample collection and analysis.The Main Plant characterization process ensured a conservative bias for estimation of area material at risk (MAR). A stratified random sampling process was employed for each wall surface to identify five survey locations.
Within each survey location the area of highest contamination was identified and smear surveys were obtained to determine alpha and beta/gamma contamination levels to aid in validation of the nuclide distribution chosen for characterization.
Direct readings for alpha and/or beta/gamma contamination were also obtained depending on background or surface condition in order to further validate the selected nuclide distribution.
Although statistical uncertainties were not developed for these estimates, the use of maximum measured values for cell characterization is believed to have introduced adequate conservatism in the analysis.No change to Plan.4)Page 26 of 94 The demolition approach may include the limited use of localized, portat>le ventilation controls to insure worker protection and public health and safety." Comment 4: Elaborate on exactly what conditions would require use of temporary enclosures/ventilation during the decommissioning.
Specifically, is this approach expected to be necessary during demolition of the structure vs equipment contained within, the structure?
If so, the plan should include more detail on this subject.At this time, no use of enclosures or portable ventilation controls is planned during MPPB demolition.
If such controls are required during demolition, it will be based on the Radiological Engineering Department's analysis of worker safety monitoring and controls and details will be provided in a Work Instruction Package (WIP). Conditions requiring the use of temporary enclosures/ventilation would include radiological activity levels at the WVDP perimeter fence line that would not allow open air demolition to continue (i.e>0.02 DAG) *'The following sentence will be added after the sentence referenced in the comment: The details of such localized controls would be based on the specific area and nature of the radioactivity/contamination levels present and would be included in a WIP." WD:2018:0081 Comment Number NRG Comment 5)Page 27 of 94"Run-off water will be controlled and dispositloned in accordance with WVDP procedures (e.g.. treated and discharged through the site's State Pollutant Discharge Elimination System [SPDES]permitted system). A berm or berms will be set up around the demolition area(s) to provide containment for dust suppression water and precipitation.
The water will be tested as directed by site procedures and transferred for treatment through the SPDES permitted low-level waste treatment facility.
Efforts will be made to minimize the volume of water by using misting techniques and a surfactant.
Storm drain inlets within the bermed area will be sealed.These practices will effectively control the volume of water to be controlled, as well as avoiding impacts to other systems, including groundwater.
to minimize the potential for the spread of contamination both inside and outside work areas." Comment 5: Please further explain in the plan how water will be collected for testing and how groundwater impacts will be mitigated.
WVDP Response The approach for water collection, including water used for dust suppression, and management will be described in an appendix to the WIP and is summarized below.Water control barriers will be in place prior to and maintained during all phases of demolition and set up around the demolition area to provide control and containment for dust suppression water and precipitation.
As currently envisioned, demolition and storm water retained behind the barriers (e.g., berms) would be pumped to collection tanks, sampled, and transferred for treatment through the WVDP low-level waste treatment facility, or othenwise dispositioned based on the sample results.The sentences identified in the comment will be revised as follows: "The water will be pumped into collection tanks, sampled and transferred for treatment through the SPDES permitted low-level waste treatment facility, or othen/vise dispositioned based on the sample results. Efforts will be made to minimize the volume of water by using misting techniques and a surfactant.
Storm drain inlets within the bermed area will be sealed. Minimizing the volume of dust suppression water and pumping collected water from the containment area will mitigate potential impacts to groundwater and minimize the potential for the spread of contamination both inside and outside work areas." 6)Page 27 of 94"The MPPB floors and below-grade structures will be coated with a fixative and/or grouted, as necessary to maintain dose ALARA, protect the surfaces from damage during demolition, minimize equipment contamination, and deter water intrusion.
Prior to placing grout, an engineering analysis will be performed to determine the thickness of grout needed to avoid damage to the underlying surfaces.
Items such as filters, cell debris, piping, and miscellaneous equipment with high levels of radioactivity will already have been removed from the building or stabilized during deactivation." Comment 6: Because the plan does not particularly address the decommissioning of the sub-grade structures nor provide any schedule for their being addressed, elaborate on how the site wiil be secured/stabiiized once the decommissioning in accordance with the plan is complete.
Specifically, will the sub-grade structures be enclosed, ventilated, and a mechanism provided for water extraction should it be necessary?
If any such approaches are needed, how long will they be needed before the sub-grade structures are decommissioned?
if such approaches are not needed, explain why.Page 28 pf 94 If necessary, additional fixatives can be applied during the demolition work process.The scope of work for this phase of demolition (Phase 1A) includes removal of the MPPB to the first floor slab (nominal 100 +/- 3-ft reference elevation).
The first floor slab and stub walls are intended to remain intact to help control storm water and to prevent surface water infiltration into the subsurface cells and soil.In addition to the grout placed prior to demolition, a cover which may include soil, gravel, and a membrane will be used to limit water intrusion and protect the structural integrity of the first floor slab and below-grade structures during and following Phase 1A demolition.
All parts of the MPPB slab and below-grade structures/foundations will be removed during the next phase of demolition (Phase IB).The following sentence will be added at the end of the first paragraph on page 28: "The below-grade portions and remaining grouted, ground-level surfaces of the MPPB will be removed during a subsequent phase of demolition." The length of time until the first floor slab and below-grade structures are decommissioned has not yet been determined.
The GPC cell structure is a below grade cell that will be sealed, and the ability to connect ventilation will be maintained.
At this time, ventilation is not planned to be reconnected to the GPC. since it is not anticipated to be needed for radiological controls prior to the next phase of MPPB demolition.
The capability to detect the presence of water will exist in the GPC. but no visual WD:2018:0081 Comment Number NRG Comment WVDP Response Comment: The plan should describe the types of situations or conditions that would cause additional fixatives to be applied.access or water removal system will be in place, since this is not believed to be necessary prior to the next phase of MPPB demolition.
Additional controls would be implemented if determined to be necessary during routine radiological surveys and monitoring.
Similar to the approach for VIT, details for when to consider the application of additional fixatives will be identified in the MPPB demolition WIP. Examples may include removed building materials that require additional processing at a later time or demolition debris that is staged, awaiting packaging into waste containers on a subsequent day.The use of additional fixatives may also be considered based on monitoring during demolition and/or waste loading.A sentence will be added to indicate that application of fixative will be considered for demolition materials that require further processing on the ground or are awaiting packaging Into waste containers.
7)Page 57 of 94'The WIP will include a radiological monitoring plan with action levels. There will be alerts set up on the Continuous Air Monitors (CAMs) that will alert the workers before a "stop work" level would be reached. Based on such an alert, the ongoing work will be evaluated to determine if the increase in activity is anticipated and what actions, if any, may be needed." Comment 7: The plan should clarify how the CAMS will be utilized.For example, what exactly will the CAMs be used to monitor (alpha, beta/gamma, etc.); how will the action leveis be established:
explain whether the action levels will address all radionuclides potentially emitted: and explain where these CAM units wili be located relative to the actual work that will occur under this work plan?The radiological monitoring plan in the WIP will identify locations and set points similar to the approach currently being implemented for VIT facility demolition.
The CAMs will be used for real time monitoring and will measure Alpha and Beta/Gamma activity.
The quantity of CAMs and their locations are being evaluated and will be identified in the final WIP.A minimum of four CAMs will be located along the 30 meter contamination area boundary.
The CAMs are typically located in small weather enclosures, with their status continuously monitored by a Radiological Controls Technician.
Additional CAMs will be located between the contamination area boundary and the boundary of the radiological buffer area, as well as beyond the buffer area boundary.A Radiological Engineering calculation will be performed to determine the CAM set points to maintain levels <3 DAC-hour per day in order to not exceed 12 DAC-hour during a 4-day, 40-hour work week. If additional days are required to be worked, an evaluation of the air monitoring data would be required by Radiological Engineering to ensure a 3 DAC-hour buffer exists for the day(s) to be worked.Similar to the approach for VIT demolition, no action levels are established for tritium or iodine-129.
Text will be added to the plan to indicate that CAMs will be used for real time monitoring and will measure Alpha and Beta/Gamma activity along the approximate 30 meter contamination area boundary and also at locations bevond the contamination area boundary.WD:2018:0081 Comment 1 . ^Number I NRG Comment WVDP Response 8)Page 58 of 94"Contamination surveys at the 30 meter perimeter locations will be performed during demolition, and demolition equipment will also be surveyed." Comment 8: The plan should provide a more detailed description of the 30 meter perimeter sampling locations and contamination survey methods.1 Similar to the previous response:
The radiological monitoring plan in the WIP will identify locations, set points, and survey methods similar to the approach currently tieing implemented for VIT facility demolition.
A minimum of four (4)real time air monitors (CAMs) will be located along the 30 meter contamination area boundary and additional text will be added to the plan.Contamination surveys will be performed in accordance with RC-RPO-104,"Performing Radiation and Contamination Surveys," with additional details identified in the MPPB demolition WIP.9)Page 60 of 94'The action levels at the perimeter of the site will be 0.02 Derived Air Concentration (DAC) which is the maximum weekly average concentration according to the AERMOD calculation and activity on the deposition mats of 20 dpm/100cm2 alpha and 1000 dpm/100cm2 beta-gamma." Comment 9: Several times in the plan, the "perimeter" is referred to rather ambiguously.
Please clarify in the plan, when not already specified, whether the perimeter being discussed is the demolition"boundaries" (demolition work site perimeter?)
as discussed on pages 61 and 62 of the plan, the V\NDP perimeter as discussed on page 61, or has some other meaning.The plan will be revised to clarify that "perimeter" refers to the site perimeter or the WVDP security fence that is referred to in the first paragraph of Section 6.5.The description of the boundaries in section 6.5 will be revised for clarification and to remove "perimeter" from the descriptions.
Figure 27 will be removed to help alleviate any confusion and since the boundary descriptions are being revised as follows: Contamination Area/Monitoring Boundary - Approximately 30 meters from the active demolition zone. CAMs will be located at this boundary to ensure worker protection levels are achieved.Buffer Area Boundary - Approximately 90 meters from the active demolition zone to keep unauthorized persons away from demolition activities and supporting functions.
10)Page 63 of 94"Radiological Characterization of the demolition debris will also be conducted in accordance with WM-210, Waste Stream Characterization for the demolition waste streams and to establish the isotopic scaling factors for the waste. Characterization of the IM containers or other containers of demolition debris will be performed in accordance with WM-250, Waste Container Characterizations and WM-230, Determining Radioactivity in a Waste Package." Comment 10: Please provide WM-210 and WM-250 to NRC for review or otherwise the plan should provide additional details on characterization of the waste and waste packages destined for disposal.The WVDP does not release program implementing procedures.
WM-210 Waste Stream Characterization, WM-250 Waste Container Characterization, and WM-230 Determining Radioactivity in a Package can be reviewed at the site.The following will be added to Section 7.1.2: "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." WD:2018:0081 Comment Number NRG Comment WVDP Response 11)General Comment 11: Because the site has fi ssile materials and it is apparent that Nuclear Criticaiity Safety (NCS) will be considered from the attached forms in the plan, the plan should provide a general overview of the NCS program and qualifications of personnel performing this function sufficient to assure that NCS wiii be appropriately addressed during the implementation of the hAain Plant Process Building work plan.The forms attached to WVDP-586 are not specific to the Plan, but are part of the standardized WVDP Integrated Safety Management Review of any proposed activity at the site, including preparations for demolition.
The Main Plant Process Building is being prepared for open air demolition and therefore the fissile material content in the facility has been reduced to levels consistent with residual surface contamination.
Estimates of fissile material in the facility, as indicated in the draft Documented Safety Analysis currently with DOE for review, indicate that approximately 2650 fissile gram equivalents (FGE) of Pu-239 remain in the entire facility.
Approximately 75% of this fissile mass Is low enriched U-235. (The effective enrichment of residual material in areas of the MPPB is less than 2 weight percent U-235.) There are no known significant holdups of material remaining in the facility.The attached text will be added as a new section 4.2 to provide an overview of the Nuclear Criticaiity Safety proqram.WD:2018:0081 Attachment to NRC Comment/Response Table for the MPPB Demolition Plan 4.2 Nuclear Criticalitv Safety Prooram Overview The criticality safety program at the WVDP has been developed to control fissionable materials and potential nuclear criticality hazards in a way that assures that workers, members of the general public, government and personal property, and essential operations are protected from the effects of an inadvertent criticality accident.Fissionable materials at the WVDP are packaged, handled, and stored in a manner that assures that the potential for an inadvertent criticality is maintained acceptably low.The criticality safety program assures that environmental, safety, and health protection matters associated with all fissile material operations at the WVDP are comprehensively addressed and receive an objective review, with all identifiable risks reduced to acceptably low levels, and that management authorization of all operations is documented.
Consideration is given to all potential criticality hazards associated with fissionable material operations.
Criticality safety at the WVDP is achieved through the application of administrative controls.
Evaluations have shown that there is no credible potential for an inadvertent criticality associated with site activities when fissile materials are packaged in conformance with site administrative controls.Administration of the criticality safety program at the WVDP is through the CHBWV Environmental, Safety, Health and Quality (ESH&Q) organization.
The ESH&Q Manager is responsible for monitoring and implementing nuclear criticality safety requirements and for assisting operating management in developing programs and plans for maintaining nuclear criticality safety by regular evaluations and assessments in work areas. The ESH&Q Manager is responsible for developing and maintaining the criticality safety program manual and for criticality safety training.Additional responsibilities of the ESH&Q Manager are listed in WVDP-162, WVDP Nuclear Criticality Safety Program Manual.The Criticality Safety Engineer (CSE) is responsible for performing nuclear criticality safety evaluations for activities conducted at the WVDP. In addition, the CSE provides programmatic evaluation to ensure that fissile materials are packaged in a manner that protects worker health and safety and the environment, and that nuclear criticality safety evaluations are performed to identify potential accumulations of fissile material during production, storage, transport, and handling.
The CSE is responsible for developing controls for fissile material accumulations to reduce the ri sk of accidental criticality.
The WVDP is supported by two CSEs that have been qualified per a DOE-approved qualification standard that was developed to meet the requirements of DOE O 420.1 C, Facility Safety, and guidance of ANSI/ANS-8.26, Criticality Safety Engineer Training and Qualification Program. WVDP criticality safety engineers are integrated into site work planning via the WVDP Integrated Safety Management System, which ensures that appropriate hazard control specialists are involved in all site work planning activities.
WD:2018:0081 Figure XX Vitrification Facility and Main Plant Process Building Following Demolition Dark Gray Represents Cell Floors that were Grouted Teal Green Represents Area Not Grouted Vitrification Facility Approximate ground level{nominal 100 +/- 3-ft reference elevation)
WD;20I8:0081