ML20059M012
| ML20059M012 | |
| Person / Time | |
|---|---|
| Site: | 07000139 |
| Issue date: | 11/08/1993 |
| From: | Chabot D ENGELHARD CORP. |
| To: | Jack Parrott NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 9311180084 | |
| Download: ML20059M012 (14) | |
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INGINilRf D M AllRIAL5 GROT >P ROUTI 152 PL AINVit1F. M A%ACHtN TT5 02NJ 60m 69k7811 illix 92-Ni90 t
November 8,1993 Mr. Jack D. Parrott, Project Manager Facilities Decommissionmg Section Decommissioning and Regulatory Services Board Division of Low-Level. Waste Management and Decommissioning Office of Nuclear Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001
Subject:
Response to Comments in Letter of September 10,1993, J.D. Parrott to D.P. Chabot, Docket No. 070-00139 L ar Mr. Parrott:
Enclosed are the responses to the comments provided by the U.S. Nuuear Regulatory Commission in the letter of September 10,1993 relative to the Engelhard Corporation i
" Decontamination Plan for the Interior of the Plainville, Massachusetts Plant of Engelhard Corporation" (the " Plan") and " Radiological Characterization Survey Program for the Plainville, Massachusetts Site of Engelhard Corporation" (the " Survey Program"). The responses are, we believe, consistent with our telephone discussion of October 4,1993.
Attachment I contains the responses to the comments on the Interior Decontaminat. m l
Plan and Attachment Il contains the resr>onses to the comments on the exterior Radiological Characterization Survey P e,m. Engelhard anticipates initiating the We would therefore request your interior decontamination in the near s
concurrence to the Plan be provided as soor.5 possible.
Please call me if further clarification is required for any of the responses.
Sincerely, n
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Donald P. Chabot Senior Environmental Engineer 4
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Jeffrey Barrett Plainville Toxic. Waste & Radiation Watch Group B12 Foxboro 69 Messenger Street Plainville, M A 02762-Robert W. Brackett, RCRA Project Manager U. S. Environmental Protection Agency, Region 1
.JFK Federal Building, Room 2203 HRR-CAN3 Boston, MA 02203-2211 William Burt, Chairman Plainville Board of Health 140 South Street Plainville, MA 02762 Jeffrey Chormann, Project Manager Massachusetts Department of Environmental Protection Bureau of Waste Prevention One Winter Street Boston, MA 02108 Engelhard Site Information Repository Plainville Public Library l
198 South Street i
4 Plainville, MA 02762 i
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A'ITACllMENT I l
l Response to U.S. NRC Comments on the Decontamiration Plan for the Interior of the Plainville. Massachusetts Plant of Encelnard Corporation ("The Plan")
a Comment No.1:
Due to the fact that radiologically contaminated effluent was j
allowed to be discharged to the onsite septic system, sewer lines inside or underneath the buildings 1 and 2 should be surveyed.
Also, the scaled pipes on the tunnel ramp should be investigated j
4 to see if they contain residual contamination.
l Respouse:
Radiologically contaminated effluent, including laundry and shower waste, was only discharged to the liquid waste disposal i
system; the sanitary waste disposal system did not receive any l
radiologically contaminated effluents. Engelhard will, as part of l
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the re-survey of the interior to be conducted prior to initiation of decontamination (see response to Comment No. 4), survey the l
drains and lines inside and underneath building 2 where nuclear fuel fabrication was conducted. 'Ihe underground piping in this system exterior to the building will be surveyed as part of the exterior Survey Program. In addition, the interior of the scaled pipes on the tunnel ramp will be accessed and surveyed for residual contamination.
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Comment No. 2:
The presence of an incinerator onsite has lead to radiological contamination of the roof, roof drains, and around the roof drain outfalls at other licensed facilities. Therefore, a plan for surveying the roof, roof drains, and the areas around the roof drain outfalls should be included. This may involve taking core samples of the roof material due to covering of the original surface from subsequent re-roofings.
Response
Engelhard will survey the roof of buildings 1 and 2, roof drains, and areas around the outfalls as part of the exterior Survey Program. 'Ihe original roof surface was subsequently covered with additional layers of insulation and roofing materials thus requiring that corings be taken to access the original surface. A reference
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grid will be established and samples collected consistent with j
treating the roof surface as an unaffected area. If radiological contamination is found in these samples, the roof (or portion thereof) will be reclassified as an affected area and additional surveys will be conducted. Locations in the roof drains and the j
i areas around the outfalls and the drainage from these areas will
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also be sampled as part of the exterior Survey Program.
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2 Comment No. 3:
Before work can begin, NRC needs to know which NRC licensed contractor will be doing the work so that their Health and Safety Plan can be evaluated.
If a non-NRC licensed contractor is selected to do the work, a Health and Safety plan needs to be approved by NRC before work can begin.
Response
Engelhard will identify the selected decontamination contractor prior to the initiation of any decontamination activities and will I
provide the NRC witl a Health and Safety Plan specifically adapted to the project parameters. It is our understanding that NRC will require 3-5 weeks to perform their evaluation of the plan.
i Comment No. 4:
There is not enough specific informa@n provided to evaluate the classification of affected versus unaffected areas. Also,it appears that the July 1988 Survey was done while the floor was covered with equipment making a comprehensive survey impossible.
Please provide the July 1988 Survey data so that NRC can ecaluate these issues.
Response
When the July 1988 survey was performed, some equipment was stillin place on the floor area of buildings 1 and 2, requiring that measurements be made around this equipment. Recognizing the need for additional survey data to better define the extent of the affected area, Engelhard is planning (see Item 1 of Section 5.0 Decontamination Work Scope of the Plan) to resurvey the t
currently classified affected and unaffected areas prior to initiating any decontamination. This resurvey will include the previously inaccessible floor areas, penetrations and crevasses, the drains and interior lines from the liquid waste disposal system, and the piping in the tunnel ramp. He July 1988 survey results will then be updated and supplemented as necessaiy, and the affected area redefined. The NRC will be provided with the updated survey results at that time, allowing sufficient time for review prior to initiation of any onsite decontamination.
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Response to Comments on the Radiolonical Characteri7.ation Survey Procram for the Plainville. Massachusetts Site of Engelhard Corporation (The " Survey Proaram")
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i Comment No.1:
Page 8. The surface scan referenced on this page and elsewhere j
will probably not be effective given the type and concentration of contamination (low-levels of enriched uranium) and the fact that most of the potentially contaminated soil areas are covered by pavement. It is suggested that the gamma scan survey be replaced by a more thorough direct soil sampling and analysis effort to cover all of the potentially affected area (See Comment No. 6).
f Comment No. 6:
Page 22.
It is not clear from the written description what sampling pattern will be used at the drywell location. A grid and sampling pattern should be established across the potentially affected areas in accordance with the NUREG/CR-5849 section on i
Open Land Surveys - Affected Areas and projected onto a map of this site. NRC would like to review the grid and sampling pattern j
before sampling begins.
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j Comment No.10:
Figures 4-5,8-2,8-3, and 8-4. The area designated as affected in Figure 4-5 is different than the sampling area defined in Figures j
8-2 through.8-4. What is needed is a designation of different potentially affected areas for the different horizons or modes of j
interest (i.e. surface soil, subsurface soil, sediment) instead of one l
potentially affected area and then different sampling areas.
4 Comment No.11:
Figure 8-2.
Due to past overflows of drywells to the surface, surface soil should be sampled in an area completely surrounding the dry wells and in drainage ways leading away from them.
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Response
Engelhard concurs that it will be very difficult to detect elevated
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radiation levels from a surface scan of the site, particularly where the site is covered with pavement. The scan was included because i
of the emphasis on its use in NUREG/CR-5849.
We will therefore, with NRC concurrence, not perform a surface scan as described in the Survey Program.
l In preparing the Survey Program, the performance of a direct surface soil and sediment sampling and analysis program consistent with the requirements with the Open Land Surveys -
i Affected Areas section of NUREG/CR-5849 has been anticipated, L
and the estimated number of samples in Table 8.1, Plainville Facility Radiological Sampling and Measurement Program, is
4 based on the projected sampling program. This program has involved the establishment of a preliminary grid and sampling pattern of the potentially affected areas as defined in NUREG/CR-5849, inclusive of the area surrounding the drywell location and the drainage ways leading from the drywell.
Engelhard will establish. a more definitive affected area-designation after the geophysical survey is performed to locate the '
components of the subsurface liquid waste disposal system and the overflow area from the leach pits (See response to Comment i
No. 4). Different potentially affected areas will be defined as required for the surface soil, subsurface soil and sediment. An
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updated grid and sampling pattern will then be established for the affected areas in each of the media based on NUREG/CR-5849 requirements. Maps of the redefined affected areas with the l
overlain grid and sampling patterns (locations, numbers) will be provided for NRC review prior to initiation of the sampling.
Comment No. 2:
Page 8.
It is stated in the text that the soil samples will be analyzed for gross (alpha and beta) radioactivity. Yet in Table 8.1, soil and sediment gross radioactivity analysis is not mentioned. In any case, it is not recommended that t.he soil and sediment -
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samples be analyzed for gross radioactivity because NRC experience at other decommissioning sites has shown that gross alpha analysis results generally do not correlate with the isotopic uranium results from the same samples. Furthermore, we do not regulate residual soil contamination by gross alpha concentration, rather this is done by total uranium concentration as determined by isotopic analyses. Therefore, it is recommended that only isotopic analysis be attempted on the soil and sediment samples.
Response
As a result of the discussion at our meeting of January 26,1993, we concurred that the soil and sediment samples would not be analyzed for gross radioactivity and the draft Table 8.1 was edited to remove the gross radioactivity measurements. However, the statement on page 8 of the text was inadvertently left ' in.
l Engelhard will have only isotopic analysis performed on the soil
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and sediment samples. A corrected version of page 8 is enclosed.
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Comment No. 3:
Page 15. Which samples will be tested for TCLP metals? Please explain why this is being done.
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5 Respoitse:
All the soil and sediment samples from the affected area will be archived subsequent to the radiological analysis.
Prior to determining the method and location for disposal of any contaminated soil and sediment, samples from affected. locations not characterized under the EPA's RCRA order will be analyzed for YCLP metals to establish whether a mixed waste is present, and thus provide a basis for estimating mixed waste volumes.
l Comment No. 4:
Page 16. On which area (s) of the site will the geophysical survey be performed? Will the survey technique (s) chosen detect burials?
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Response
Engelhard will use an experienced geophysical survey contractor to employ Ground Penetrating Radar (GPR) to locate the components (piping, leach pits) of the original and expanded subsurface liquid waste disposal system. ' Die GPR survey will be i
conducted in the open yard area south of building 2 from the building wall south and then east past the drywell to an area approximately 30 feet east of the southeast corner of the building where historical documentation indicates the leach pits are located. GPR is a proven technique that has been successfully used in numerous comparable situations to detect piping and other i
components comparable to those in the liquid waste disposal system.
Comment No. 5:
Page 20. Is building 12 the one that now lies over the former drum storage area? Will potentially affected areas under the buildings also be sampled?
Response
Based on available historical drawings and documents, the former drum storage area lies under building 12 and/or the adjacent yard area. As stated on page 20 of the Survey Program, samples w;11 be collected from these locations. In addition, samples vill be collected from under the floor pad of building 3,which is located just south of building 12 and west of building 2. (See Figure 3-1 of the
.vey Program)
Comment No. 7:
Page 23. How many unaffected area surface soil samples will be taken?
Response
Sampling of the unaffected area surface soil will be performed as described in Open Land Survey - Unaffected Areas of NUREG/CR-5849. A minimum of 30 randomly selected locations
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will be sampled.
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Comment No. 8:
Table 4.4. The sample analysis of the drilling mud from MWO5 indicates presence of Th-228, Pu-238, and Pu-239. Your isotopic analysis should include these isotopes to either confirm or deny their presence in the soil, sediment and groundwater at the site.
Response
While the ana;ysis of the drilling mud from MWO5 does show elevated (above background) levels of these constituents, we i
believe the results are anomalous and not representative of the concentrations in the media. There is no historical data that would point to the presence of these constituents, nor did the residual sample from the bottom of the drywell (Table 4.11) have elevated levels of H-228, Pu-238, or Pu-239. However, Engelhard will have the surface and subsurface soil samples in the grids adjacent to the drywell and groundwate-r samples from MWO5 analyzed for these isotopes. If elevated levels are detected in i
these samples, all the media samples from the affected area will be analyzed for these isotopes in addition to U238, U235, and U234.
If however, concentrations are at background levels the analysis of the other media samples from the affected area will be limited to U238, U235, and U234.
i Comment No. 9:
Tables 4.9 and 4.11. The units are in pCi/l; they should be in l
pCi/g.
Response
The units should be in pCi/g. Corrected versions of Tables 4.9 and 4.11 are enclosed.
Comment No.12:
Please provide a groundwater table map and topographic map of the site on the same scale as the Site Plan in Figure 3-4.
Response
A groundwater table map and topographic map will be provided when available.
Comment No.13:
Are there any drainage / sewer lines beneath the buildings that were in use during the licensed period? If present, these also need to j
be surveyed.
Response
The drainage lines from the liquid waste disposal system which drained from locations in the fucl fabrication rooms in building No. 2 to the south of building 2 will be surveyed as part of interior decontamination program. (See response to Comment No.1 in Attachment I)
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i Comment No.14:
Radiological release criteria for potentially contaminated.
equipment used onsite should be referenced; acceptable criteria are presented in U.S. NRC Regulatory Guide 1.86.
Response
All equipment and vehicles used onsite will be decontaminated and monitored prior to release. The release criteria will be those specified in NRC Regulatory Guide 1.86.
For the uranium isotopes these are; 2
Average - 5000 dpm/100 cm y Removable - 1000 dpm/100 cm y 2
2 Maximum - 15000 dpm/100 cm y t
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8 been developed to further characterize radioactivity in the soil, groundwater, surface water sediments, and air at the Plainville site:
A surface gamma scan of the onsite yard external to the plant on a referenced grid
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encompassing the "affected" area and adjacent open and paved areas.
- Emplacement of additional borings in the region at the south end of the site where elevated radioactivity has been detected, and collection and analysis of surface and subsurface soil samples in the grid blocks for selected radionucliden. Additional surface soil samples will be collected from any grids with elevated gamma levels.
Collection and analysis of additional groundwater samples from existing monitoring _
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wells for selected radionuclides. Collection and radionuclide analysis of additional sediment samples along Tu npike Lake shoreline adjacent to the south end of the e
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- Perimeter (boundary) and onsite monitoring of airborne particulates for specific radionuclides.
- Emplacement of borings through the floor pad of buildings 12 and 3 in the region or the former incinerator and exterior waste storage area, and collection and analysis of surface and subsurface soil samples for selected radionuclides.
- Use of sub-surface geophysical techniques to locate the components of both the original and expanded onsite subsurface liquid waste disposal system (piping, leach pits, etc.) generally south and east of the south end of the plant building. Once the components have been located, soil borings will be emplaced in a pattern through i
this region to encompass the potential overflow area, and surface and subsurface Revised 11/5/93 o
9 soil samples will be collected and analyzed for selected radionuclides. Additional monitoring wells will be installed in this region (if required) and groundwater i
samples collected for radionuclide analysis.
The components of this Radiological Characterization Program are described in Section 8.0.
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i 57 TABLE 4.9 Summary of Sediment Analysis Results (Gross Alpha and Beta) l Monit.
Date Measured Depth Gr. Alpha -
Gr. Beta Point Yr. Mo. Date (ftj (pCi/g)
(pCi/a) i i
SWO1 87.0902 0.0 to 0.5 126.00 27.50 l
SWO2 87.0902 0.0 to 0.5 3.20 2.51 I
SWO3 87.0902 0.0 to 0.5 0.44 0.92 I
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SWO4 87.0902 0.0 to 0.5 0.70 1.15 l
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59 TABLE 4.11 Radiological Analysis of " Sediment" Sample from Drywell e
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Radionuclide Concentration (pCihn Gross Alpha 83
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Gross Beta 84 U238 26 U234 38 r
U235 4.30 Th-230 0.22 Ra-226 0.41 i
Th-232 0.07 i
Th-228 0.43 Ra-228 0.55 Po-238 0.01 Po-239
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Revised 11/5/93 1
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