ML20132C225
| ML20132C225 | |
| Person / Time | |
|---|---|
| Site: | 07000133 |
| Issue date: | 11/27/1996 |
| From: | SEVENSON ENVIRONMENTAL SERVICES, INC. |
| To: | |
| Shared Package | |
| ML20132C220 | List: |
| References | |
| NUDOCS 9612180234 | |
| Download: ML20132C225 (29) | |
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i Site Characterization Report 3
For l
Former i
CLEVITE CORPORATION SITE East 105 Street, Cleveland, Ohio i
Submitted Bv-SEVENSON ENVIRONMENTAL SERVICES, INC.
2749 Lockport Road Niagara Falls, NY 14302 i
Revised November 27,1996 9612180234 961127 PDR ADOCK 07000133 PDR J
1 Background / Site Description The former Clevite Corporation Facility is located at 540 East 105th Street, Cleveland, Ohio. This site is presently owned by Neighborhood Progress, Inc.
Clevite Corporation was a manufacturer of nuclear fuel under an Atomic Energy Commission license, including high-enriched uranium fuel for the U.S. Navy and AEC research reactors, as well as Thorium products. The company ceased fuel manufacturing in the 1960's. A closeout radiation survey by the licensee was accepted by the AEC, and the license was terminated. The 160,000 square foot building was sold in 1991 to Neighborhood Progress, Inc.,
and has been divided into smaller sections for lease.
On May 27,1993, a Region III (Chicago) radiation specialist performed a radiation survey at the site which had been identified as a potentially contaminated site in an Oak Ridge National Laboratoy review of former AEC and NRC licenses.
The survey identified low-level radioactive contamination in some cracks and crevices in the concrete floor of one portion of the building now occupied by a machine shop.
The machine shop area was surveyed because blueprints in the AEC license file identified it as a fuel manufacturing area. Other areas of the building were surveyed on a sampling basis, and no contamination was identified. Selected areas outside the building were also surveyed, and no contamination was identified.
Based upon its May 27,1993 survey, the NRC concluded that the first floor machine shop and a few assembly areas were not decontaminated to a residual radiation level consistent with NRC Guidelines. However, the NRC also concluded these radiation levels do not constitute an i
immediate health and safety problem. Although the NRC believes there is no immediate danger, the NRC believes its measurements exceed NRC limits for unrestricted use.
2 Identity of Potential Contaminants and Release Guidelines Based on known licensed operations at the site the isotopes have been identified to be:
U-235 U-238 Th-Nat or Th-232 On the basis oflack of knowledge as to where the Th-232 was used and that the Thorium has the most restrictive limits, all radioactive contaminates were assumed to be Th-232. On the basis of this the guidelines were as follows:
Average 1,000 dpm/100 cm squared averaged over 1 m squared I
s
Maximum 3,000 dpm/100 cm squared applied to <100 cm squared Removable 200 dpm/100 cm squared Soil Contamination Guideline 30 pCi/g 3
Final / Characterization Sun'ey Procedures 3.1 Survey Objectives The characterization survey is intended to provide sufficient detail to plan the decontamination effort. Sevenson used the protocols of a final status survey to perform the characterization survey. The purpose of the final status survey is to demonstrate that the radiological conditions at the former Clevite Site satisfy the NRC guidelines and that the plant site can be released for unrestricted use. Sevenson will use data obtained during the characterization survey as final survey data in unaffected areas. The specific objectives of the survey are to show that:
A.
Surface Activity ofBuildings & Structures 1.
Average surface contamination levels are within the allowed levels.
2.
Small areas of residual activity, known as " hot spots" do not exceed three times the average value. The " hot spot" limit applies to areas up to 100 cm squared. The average activity level within the 1 m squared area containing a " hot spot" must be within the guidelines.
3.
Reasonable efforts have been made to clean up removable activity and the removable activity does not exceed 20% of the average surface activity guidelines.
4.
Exposure rates in occupiable locations are less than 5 pR/hr above background. Exposure levels are measured at I m from floor and wall surfaces and are averaged over floor areas of 10 m squared.
B.
Volume Activity of Soil & Building Materials 1.
Average radionuclide concentrations are within the authorized value. Averaging is based on a 100 m squared grid area.
2.
Reasonable efforts were made to identify and remove " hot spots" that exceed the average guideline by greater than a factor of the square root of(100/A) where A is the area of the hot spot in m squared.
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C.
Exposure Rate 1.
Exposure rates do not exceed 5 pR/hr above background at one meter from the surface. Exposure rates may be averaged over 100 m squared grid areas. Maximum exposure rates over any discrete area may not exceed 10 R/hr.
The above conditions were demonstrated at a 95% confidence level for each survey unit as a whole. The survey data will be used to calculate the totalinventory ofisotopes on the site.
3.2.
Organization nnd Responsibilities The survey was performed by a qualified team of Sevenson Environmental employees.
l Mr. Anthony Certo-Site Superintendent. His duties are overall responsibility for work j
operations.
Mr. Rory Grube-Radiological Safety Officer / Health Physicist. His duties are to supervise and perform radiological monitoring and analysis, review and evaluate radiological surveys, prepare reports.
Mr. Scott Wasmer-Health Physics Technician. His duties are to perform radiological monitoring, collect environmental samples, assist in report preparation, enforce site safety and health plan.
Mr. Paul Hitcho-CIH, Health and Safety Oflicer. His duties are to develop implement and update as appropriate,,nd enforce the site specific safety health and emergency response plan.
Mr. John Davis-CHP. QA/QC. His duties were to coordinate allinterface requirements during the survey process, ensure that all aspects of the QA is adhered to.
i Site Supv H&S Rad Safety QA/QC HP Tech 3
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3.3 INSTRUMENTATION Table I lists the instrumentation to be used for the survey activities, along with typical parameters and detection sensitivities for the instrumentation and survey technique.
Sensitivities for scanning techniques are based on movement of the detector over the surface at 1 detector width per second and use of audible indicators to sense changes in instrument count rate. Experience demeristrates that qualified surveyors can detect the levels listed in Table I with a 90% confidence level. All instruments were calibrated a minimum of once every 6 months, using NIST-traceable standards. Calibration was for the specific uranium radiation enert,ies expected to be present at tiie site. Operational and background checks were performed at least once each 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> on instrument use.
The basic equations fbr determining field instrument detection limits are-l Surface Activity Measurement for an integrated measurement over a creset time MDA = 2.71 + 4.65 MDA= Activity level in dpm/100 cm2 A
B=
Backgroung cpm l
t E,
- 100, t=
count time in minutes s
2 A=
Active probe area in cm j
E=
Detector efliciency (1) MDA Surface Activity Measurement of a Ratemeter Instrument 4.65 1 MDA= Activity levelin dpm/100 cm 2
' E'*""
'E l
MDA =
j' t, =
meter time constant l
f E-A=
Active probe area in cm 2
100' 4
E=
Detector efliciency (2) MDA Scanning MDA l
4
0 8
MDA = Activity levelin dpm/100 cm2 Br=
Background rate l
3*Br E=
Detector efficiency l
MDA=
E
- A/100 A=
Area of probe l
(3) MDA Scanning l
I Laboratory Analysis of Wines l
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.71 + 4.65 /B t MDA= Activity level in dpm/100 cm l
2 y
MDA-(t) - (E)
Bg =
Background cpm l
t=
count time in minutes l
E=
Dctector efliciency l
(4) MDA l
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Table 2 INSTRUMENTATION FOR RADIOLOGICAL SURVEYS I
Type of Measurement Detector Meter
Background
4x Efr Detector Sensitivity Surface Activity Ludlum 43-68 Ludlum 2221 4 - 5 cpm 20 %
100 dpm l:
alpha 100 cm Window l-2 Gas Proportional l:
Surface Activity Beta Ludlum 43-68 Ludlum 2221 150 cpm 48%
Scan 1250 dpm l.
100 cm Window Direct 165 dpm l
2 Gas Proportional l
Surface Scan Alpha Ludlum 43-65 Ludlum 3 1 - 2 cpm 15 %
80 dpm 50 cm Window Ludlum 4 2
Scintillation Surface Scan Ludlum 44-9 Ludlum 3 20 - 40 cpm 19 %
2000-4000 dpm Beta / Gamma 15.5 cm Window Ludlum 4 2
Pancake Surface Activity Ludlum 43 65 Ludlum 3 1 - 2 cpm 15 %
200 dpm Alpha 50 cm Window Ludlum 4 2
Scintillation Surface Activity Ludlum 44-9 Ludlum 3 20 - 40 cpm 19 %
400-800 dpm Beta / Gamma 15.5 cm Window Ludlum 4 2
Pancake Surface Activity 43-1-1 Ludlum 2224-1 0.2 - 2 cpm a 27%a 14 - 26 dpm a 1.j ha/ Beta / Gamma 140 - 160 cpm py 47%py 163 - 175 dpm py p
Surface Scan 43-1-1 Ludlum 2224-1 0.2 - 2 cpm a 27%a 2 - 17 dpm a i
Alpha / Beta / Gamma 140 - 160 cpm py 47%Dy 1191 - 1361 dpm py Surface Scan Gamma 1 X 1 Nal Ludlum 3-97 7 - 10 pR N/A 4pR 6
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l Table 2
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3 INSTRUMENTATION FOR RADIOLOGICAL SURVEYS Exposure Rates I X 1 Organic Crystal W.B. Johnson 4-5pR N/A 3pR Model GSM160 pR Meter i
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SURVEY PROCEDURE l
l 3.4.1 AREA CLASSIFICATION For po ases of establishing the sampling and measurement frequency and pattern, the site has been j
dividea into affected and unaffected areas. The basis for these classifications are:
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AffectedAreas: Areas that have potential radioactive contamination (based on plant l
operating history) or known radioactive contamination (based on past of preliminary j
radiological surveillance). This includes areas where radioactive materials were used and stored, where records indicate spills or other unusual occurrences that could have resulted in l
spread of contamination. Areas immediately surrounding or adjacent to locations where radioactive materials were used or stored, or spilled were included in this classification because of the potential for inadvertent spread of contamination. Affected areas include the first floor machine shop and the hallway outside the first floor machine shop and fuel assembly area.
UnaffectedAreas: All areas not classified as affected. These areas are not expected to contain residual radioactivity, based on a knowledge of site history and previous survey information. These areas include the remaining first floor, second floor, roof, basement, and remaining site areas.
3.4.2 REFERENCE GRIDS Grids were established for the purpose of referencing locations of samples and measurements, relative to building and other site features. The gridding intervals are based on the potential for residual contamination in the various plant areas. All affected building area floor and lower wall (up to 2m) surfaces were gridded at 1 m intervals; upper walls and ceilings of affected are were also gridded a 1m intervals, if residual activity above 25% of the guideline is known or suspected. Building surfaces in unaffected areas or those upper surfaces in affected areas that have not been contaminated as a result of prior activities were not gridded; measurements were referenced to other grid systems or to prominent building feature. Affected outside areas were gridded at 10 m intervals; unaffected areas were not gridded.
The facility was divided into " survey units" having common history, contamination potential, or that are naturally distinguishable from other site areas. The survey units were sized to assure a minimum of 30 measurement locations each for floors and lower walls, other vertical surfaces, and other horizontal surfaces.
Areas identified by scans or direct measurements as exceeding guidelines were reclassified as affected areas and were gridded and resurveyed accordingly. Those areas where the elevated activity was due to fluctuations in background levels were not reclassified. These areas are identified room by room in section 4.1. This decision was based on the type of material and the fact that no alpha contamination existed. It should be noted that both uranium and thorium are alpha emitters.
3.4.3 SURFACE SCANS I
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Scanning of surfaces to identify locations of residual surface and near-surface activity were performed according to the following schedule:
Affec:cd Areas Surfaces - 100% of surface Non-contaminated upper surfaces in affected areas - scans in immedlate vicinity af measurement Unaffected Area Surfaces - 10% ofIower surface Building interior surface scans were conducted for alpha, beta, and gamma radiations. Scans of exterior building and paved surfaces were for beta and gamma radiations. Soil surfaces were scanned for gamma radiations only.
Instrumentation for scanning is listed in Table 1. The instruments having the lowest detection sensitivity were used for the scans, wherever physical surface conditions and measurement locations permit.
Scanning speeds were no greater than 1 detector width per second for alpha and beta detection instruments and 0.5 m per second for gamma instruments. Built in unimorph speakers were used to identify locations, having elevated (1.5 to 3 times ambient) levels of direct radiation. All scanning results were noted on standard field record forms; locations of elevated radiation were identified for later investigation.
Reasonable efforts were made to clean surfaces and to remove coverings prior to conducting surveys.
3.4.4 SURFACE ACTIVITY MEASUREMENTS Direct Measurements Direct measurements of alpha, beta, and/or beta-gamma surface activity were performed at selected locations using instrumentation described in Table 1. Unless precluded by surface conditions or physical parameters, the most sensitive of the instruments listed for surface measurements (Table 1) were used. Measurements were conducted by integrating counts over a 1 minute period.
Because scanning techniques are not capable of detecting residual thorium activity at <25% of the guideline level, direct surface activity measurements were systematically performed at 1 m intervals on floors and lower walls of affected areas and at the same intervals on upper surfaces that may have residual activities in excess of 25% of the guideliries.
On upper surfaces of affected areas residual activity, measurements were performed at minimum of 30 locations each on vertical and horizontal surfaces. These locations included surfaces where radioactive material would likely settle, and suflicient additional locations to provide coverage at a minimum average of 1 locations per 20 m squared of surface area.
On surfaces of unaffected areas, a minimum of 30 random measurements or an average measurement 9
i of 1 per 50 m squared of building surface area, whichever is greater, were performed for each survey unit. These locations included all building surfaces.
Removable Contamination Measurements A smear for removable contamination was performed at each measurement location.
3.4.5 EXPOSURE RATE MEASUREMENTS Gamma exposure rates were measured a 1 m above ground or floor surfaces, using a pressurized ionization chamber or a gamma scintillation instrument, calibrated for Thorium energies.
Measurements were uniformly spaced according to the following pattern:
Building Interiors:
AffectedAreas: 1 measurement per 4 m squared.
UnaffectedAreas: 1 measurement per 200 m squared.
Grounds:
AffectedAreas: 5 measurements per 100 m squared grid block.
UnaffectedAreas: 50 measurements at randomly selected locations.
3.4.6 SOIL / SEDIMENT SAMPLING Unaffected land areas surrounding the building had 30 soil samples taken at random locatiort Surface measurements were made at 30 random locations on paved areas.10% of allland ma v.1 areas were scanned for beta / gamma contamination. Areas ofconcrete in which radiation sums te be entrained were cored and subsoil samples were taken for analysis. Chain of custody proceca svew followed for all samples.
3..f.7 SPECIAL MEASUREMENTS AND SAMPLES Buildinginteriors:
Remaining ducts, electrical boxes, conduit, or other interior surfaces in affected areas, which may contain residual contamination, were accessed at random and measurements of direct and removable activity performed. Swabs were obtained from insides of wall and floor penetrations, anchor bolt holes, and floor cracks or expansion joints.
Building Exteriors:
Measurements of direct and removable activity were performed on exterior and interior surfaces of air exhrust equipment and at representative locations on roof drains. Samples of roofing material were obtained where direct measurements suggest possible entrained contamination.
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Grounds:
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Black top in the parking lots varied in thickness from approximately 4" to 16".
3.5 BACKGROUND
LEVEL DETERMINATIONS Initial background exposure rates were determined for the building interior by taking a minimum of 10 measurements at locations of similar construction but without a history of radioactive materials use.
Also, a minimum of 10 locations for area background measurement and sampling were selected within a 0.5 to 10 km radius of the site. Exposure rate measurements were performed using a micro R meter.
A background soil sample was collected. Results of background exposure rate and thorium soil concentrations were evaluated to assure that the averages determined are representative of the tme averages, using procedures described in NUREG/CR-5849. Additional sampling or measurements were performed if necessary to satisfy criteria.
3.6 SAMPLE ANALYSIS Smears and swabs for removable contamination were analyzed for gross alpha, gross beta activity.
Soil, sediment, gravel, roofing material, and other large volume samples were analyzed for l
Thorium / Uranium by gamma spectrometry; total thorium were calculated on the basis of previously determined (Section 3.2) isotopic activity ratios for this site. Sa nples of paint, residue, and other samples of small volume were analyzed for Thorium / Uranium by wet chemical separation and alpha spectroscopy.
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Laboratory chain-of-custody procedures were observed for all sample analyses.
l 3.7 DATA INTERPRETATION Measurement data were converted to units of dpm/100cm (surface activity), pR/hr (exposure rates) and pCi/g (soil concentrations) for comparison with guidelines. Values were adjusted for j
contributions from natural background. Individual measurements and soil levels were compared with
" hot-spot" criteria. Average values for survey units were determined and compared with guideline levels. Data for each survey unit were tested against the confidence level objective, using guidance and procedures described in NUREG/CR-5849.
Remediation and/or further sampling and measurements will be performed where guidelines are not met or cannot be demonstrated to the specified level of confidence. Computations and comparisons will be repeated, as necessary.
The unusual alpha to beta ratio can be attributed to the methods used for survey area preparation.
Sevenson removed tile, glue, paint, etc. that was added after the time that the facility was originally l
surveyed. During the course of removal it is believed that all of the surface contamination was l
removed leaving only contamination in cracks crevices and depressions in the surface. Because of the increased distance from the probe and any residual material it is not unreasonable to have aa abnormal l
alpha to beta ratio.
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3.,8 RECORDS All original stirvey data is being retained at the Clevite site until the completion of the remediation arid final status surveys. The original survey data will be forwarded to and archived by Gould Electronics Inc. and will be held until such time as a.horized by the NRC for disposal 4
SURVEY FINDINGS AND RESULTS i
Appendix E contains tables of data, affected during the survey. Data are summarized in tables of Appendix F; Appendix F also contains results of data interpretations and comparisons with guidelines
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and conditions established as survey objectives.
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4.i RESULTS BY ROOM 4.1.1 Basement 4.1.1.1 Boiler Room / Entrance - 32 grids greater than or equal to 25% of the guideline value of which 7 are greater than or equal to 1000 dpm/100cm (direct). Elevated readings due to naturally occurring radioactive material in structural material. 6 of the seven readings greater than 1000 dpm/100cm2 were on brick walls in close areas. These readings are due to the natural fluctuations in background. The seventh reading greater than 1000 dpm/100cm: was on a twelve inch tile drain pipe. Tile drain pipe has naturally occurring radioactive in it as on site sampling has indicated.
4.1.2 South East Wing,1st Floor 4.1.2.1 Room e 1. I18 grids greater than or equal to 25% of the guideline value of which 2 are greater than j
or equal to 1000 dpm/100cm2 (direct). 2 grids greater than or equal to 25% of the guideline value of which 1 is greater than or equal to 200 dpm/100cm (smearable). This room was surveyed as an 2
affected area. This room contained four anchor bolt holes. The contamination was from a single source and in a limited area.
4.1.2.2 Room # 2 - 219 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). I grid greater than or equal to 25% of the guideline value of 200 dpm/100cm (smearable).
2 This room was surveyed as an affected area.
4.1.2.3 Room u 7 - 75 grids greater than or equal to 25% of the guideline value of which 13 are greater than or equal to 1000 dpm/100cm (direct). I grid greater than or equal to 25% of the guideline value of 200 dpm/100cm:(smearable). 3 grids were greater than or equal to 3000 dpm/100cm (direct). This 2
room was surveyed as an affected area. The contamination was under the wall between room # 7 and room # 18. The contamination was from a single source and in a limited area.
4.1.2.4 Room
- 8 - 15 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm (direct).
2 This is the room where the Dew Pointer was found,20 mrem /hr @ contact with source,2 mrem /hr contact with case. This room was surveyed as an afTected area. The elevated activity readings are attributed to naturally occurring radioactive material in the structural material. A clay tile pipe contributed to the elevated activity at the drain.
4.1.2.5 Room e 9 - 41 grids greater than or equal to 25% of the guideline value of which 11 are greater than or equal to 1000 dpm/100cm: (direct). 41 grids greater than or equal to 25% of the guideline value of which 36 are greater than or equal to 200 dpm/100cm (smear 2.ble). I grid was greater than or equal 2
to 3000 dpm/100cm: (direct). This room was surveyed as an afTected area. The contamination in this room was a continuation from the hallway.
4.1.2.6 Room d 10 - 7 grids greater than or equal to 25% of the guideline value ofwhich 3 are greater than or equal to 1000 dpm/100cm: (direct). This room was surveyed as an affected area.
4.1.2.7 Room # / / - 94 grids greater than or equal to 25% of the guideline value of which 3 are greater than or equal to 1000 dpm/100cm:(direct). This room was surveyed as an affected area. The contamination was found under the sliding pocket door from the hallway. The other elevated activity readings are attributed to naturally occurring radioactive material found in the structural material.
4.1.2.8 Room e 12 - 24 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material. This room was surveyed as an affected area.
4.1.2.9 Room a 13 - 47 grids greater than or equal to 25% of the guideline value of which 3 are greater than or equal to 1000 dpm/100cm:(direct). I grid was greater than or equal to 3000 dpm/100cm2 (direct).
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This room was surveyed as an affected area.
4.1.2.10 Room # 14 - 69 grids greater than or equal to 25% of the guideline value of which 2 are greater than or equal to 1000 dpm/100cm (direct). I grid was greater than or equal to 3000 dpm/100cm (direct).
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This room was surveyed as an affected area.
4.1.2.11 Room # 15 - 1 grid greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct).
The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.2.12 Room a 18 - 72 gdds greater than or equal to 25% of the guideline value of which 28 are greater than or equal to 1000 dpm/100cm:(direct). I grid greater than or equal to 25% of the guideline value of which 1 is greater than or equal to 200 dpm/100cm: (smearable). 7 grids were greater than or equal to 3000 dpm/100cm (direct). This room was surveyed as an affected area. The contamination in this room was isolated to under the wall adjoining room # 7.
4.1.2.13 Sections /A B. C. etcJ - 60 grids greater than or equal to 25% of the guideline value ofwhich 15 are greater than or equal to 1000 dpm/100cm (direct). 5 grids greater than or equal to 25% of the 2
guideline value of 200 dpm/100cm:(smearable). 9 grids were greater than or equal to 3000 I
dpm/100cm (direct). The hallway, where it joins the west wing, was identified as contaminated above 2
the guideline value and was reclassified as affected. The rest of the areas remained unaffected and the elevated activity is attributed to naturally occurring activity in structural material.
4.1.2.14 Test Ce// - 26 grids greater than or equal to 25% of the guideline value of which 14 are greater than or equal to 1000 dpm/100cm (direct). I grid greater than or equal to 25% of the guideline value of 200 2
dpm/100cm:(smearable). 7 grids were greater than or equal to 3000 dpm/100cm (direct). This room 2
was surveyed as an affected area. This room contained contaminated sand.
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4.1.3 South East Wing,2nd Floor 4.1.3.1 Reof-52 grids greater than or equal to 25% of the guideline value of which 1 is greater than or equal to 1000 dpm/100cm:(direct). All of the roof areas exhibited elevated activity levels. Samples from the roof, counted on site for informational purposes only, indicated no thorium or uranium contamination.
A sample sent for uranium and thorium activity determination indicated no uranium and thorium. It is i
therefore believed that the roof area as a whole is either contaminated with naturally occurring radioactive material or from fall out from nuclear testing and is beyond the scope of the survey guidehnes.
4.1.4 West Wing,1st Floor 4.1.4.1 Weld Shov - 117 grids greater than or equal to 25% of the guideline value of which 8 are greater than or equal to 1000 dpm/100cm:(direct). 3 grids were greater than or equal to 3000 dpm/100cm2 (direct). This room was surveyed as an affected area. This room is being used for welding with thoriated tungsten rods. This room will be surveyed last after clean-up to minimize the time between remediation and final status survey.
4.1.4.2 Elevator Entrance - 29 grids greater than or equal to 25% of the guideline value of which 8 are greater than or equal to 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.4.3 Inside Dock Area - 61 grids greater than or equal to 25% of the guideline value of which 26 are greater than or equal to 1000 dpm/100cm:(direct).1 grid greater than or equal to 25% of the guideline value of 200 dpm/100cm2 (smearable). 21 grids were greater than or equal to 3000 dpm/100cm (direct). This room was surveyed as an affected area.
2 4.1.4.4 Tin Shed /Outside West Wine) - Found a glassjar of thorium oxide. This room was surveyed as an 14
affected area.
4.1.4.5 Halheav - 415 grids greater than or equal to 25% of the guideline value of which 82 are greater than or equal to 1000 dpm/100cm2 (direct). I1 grids greater than or equal to 25% of the guideline value of which 4 are greater than or equal to 200 dpm/100cm (smearable). 45 grids were greater than or equal 2
to 3000 dpm/100cm2 (direct). This room was surveyed as an affected area.
3 4.1.4.6 Stairwell-84 grids greater than or equal to 25% of the guideline value of which 9 are greater than or equal to 1000 dpm/100cm (direct). The elevated activity levels are attributed to naturally occurring 2
i radioactive material found in the stmetural material.
4.1.4.7 Room e 1 - 28 grids greater than or equal to 25% of the guideline value of which 8 are greater than or i
equal to 1000 dpm/100cm2 (direct). 6 grids were greater than or equal to 3000 dpm/100cm2 (direct).
This room was surveyed as an affected area.
4.1.4.8 Room e 2 - 46 grids greater than or equal to 25% of the guideline value of which 16 are greater than or equal to 1000 dpm/100cm (direct).12 grids were greater than or equal to 3000 dpm/100cm 2
2
- (direct). This room was surveyed as an affected area.
4.1.4.9 Room e 3 - 175 grids greater than or equal to 25% of the guideline value of which 7 are greater than or equal to 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring 1
radioactive material found in the structural material.
4.1.4.10 Room # J - 65 grids greater than or equal to 25% of the guideline value of which 8 are greater than or 4
equal to 1000 dpm/100cm (direct). The elevated activity levels are attributed to naturally occurring 2
j radioactive material found in the structural material.
4.1.4.11 Room E 5 - 30 grids greater than or equal to 25% of the guideline value of which 27 are greater than or equal to 1000 dpm/100cm2 (direct). 4 grids greater than or equal to 25% of the guideline value of 200 dpm/100cm2 (smearable). 23 grids were greater than or equal to 3000 dpm/100cm2 (direct). This room was surveyed as an atTected area.
4.1.4.12 Room E 6 - 124 grids greater than or equal to 25% of the guideline value of which 14 are greater than i
or equal to 1000 dpm/100cm (direct). 6 grids were greater than or equal to 3000 dpm/100cm2 2
j (direct). Yhis room was surveyed as an affected area.
4 4.1.4.13 Room E 7 - 140 grids greater than or equal to 25% of the guideline value of which 25 are greater than or equal to 1000 dpm/100cm2 (direct). 3 grids were greater than or equal to 3000 dpm/100cm2 a
i (direct). This room was surveyed as an affected area.
4.1.4.14 Room e 8 - 162 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 j
(direct). The elevated activity levels are attributed to naturally occurring radioactive material found in i
the structural material.
i 4.1.4.15 Room E 9 - 14 grids greater than or equal to 25% of the guideline value of1000 dpm/100cm (direct).
2 The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.4.16 Room # 10 - 39 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm 2
{
(direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.4.17 Room 31/ - 134 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in j
the structural material.
i 4.1.4.18 Room e 12 - 25 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.4.19 Room e 13 - 43 grids creater than or equal to 25% of the guideline value of 1000 dpm/100cm2 15
(direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the stmetural material.
4.1.4.20 Room # l./ - 134 grids greater than or equal to 25% of the guideline value ofwhich 3 are greater than or equal to 1000 dpm/100cm2 (direct). This room was surveyed as an affected area.
i 4.1.4.21 Room # 15 - 164 grids greater than or equal to 25% of the guideline value of which 61 are greater than or equal to 1000 dpm/100cm2 (direct). 27 grids were greater than or equal to 3000 dpm/100cm2 (direct). This room was surveyed as an affected area.
4.1.4.22 Room a 16 - 577 grids greater than or equal to 25% of the guideline value of which 182 are greater than or equal to 1000 dpm/100cm2 (direct). 28 grids greater than or equal to 25% of the guideline value of which 16 are greater than or equal to 200 dpm/100cm (smearable). 93 grids were greater 2
than or equal to 3000 dpm/100cm2 (direct). Furnace in room was used for smelting depleted uranium.
This room was surveyed as an affected area.
4.1.4.23 Room # 17 - 61 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in l
the structural material.
4.1.4.24 Room # 18 - 37 grids greater than or equal to 25% of the guideline value of which 1 is greater than or i
equal to 1000 dpm/100cm2 (direct). I grid was greater than or equal to 3000 dpm/100cm (direct).
2 j
This room was surveyed as an affected area.
l 4.1.4.25 Room # 19 - 23 grids greater than or equal to 25% of the guideline value of which 2 are greater than i
or equal to 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
j 4.1.4.26 Room # 20 - 100 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in j
the structural material.
i 4.1.5 West Wing 2nd Floor j
4.1.5.1 Sections /A B. C. etc.) - 36 grids greater than or equal to 25% of the guideline value of which 2 are l
greater than or equal to 1000 dpm/100cm (direct). The elevated activity levels are attributed to 2
naturally occurring radioactive material found in the structural material.
4.1.6 West Wing 3rd Floor 4.1.6.1 Sections /A B. C. etc.) - 32 grids greater than or equal to 25% of the guideline value of which 3 are l
greater than or equal to 1000 dpm/100cm (direct). The elevated activity levels are attributed to 2
naturally occurring radioactive material found in the structural material. Areas of particular interest l
were the bathrooms. Drain pipes in the bathrooms are made of tile pipe. The drains are contained in 1
brick walls of which one is covered by glazed tile (glazed tile had the highest background).
l 4.1.7 West Wing 4th Floor 4.1.7.1 Roof _- 115 grids greater than or equal to 25% of the guideline value of which 6 are greater than or 4
equal to 1000 dpm/100cm (direct). 2 grids greater than or equal to 25% of the guideline value of 2
j which 1 is greater than or equal to 200 dpm/100cm2 (smearable). 2 grids were greater than or equal to j
3000 dpm/100cm (direct). All of the roof areas exhibited elevated activity levels. Samples from the 2
i roof, counted on site for informational purposes only, indicated no thorium or uranium contamination.
A sample sent for uranium and thorium activity determination indicated no uranium and thorium. It is therefore believed that the roof area as a whole is either contaminated with naturally occurring i
radioactive material or from fall out from nuclear testing and is beyond the scope of the survey 16 1
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guidelines. The exhaust duct fan was located on the 4th floor roof and was the source of
(
contamination on the roof. The location where the fan had been was surveyed as affected.
l 4.1.7.2
&ctions /A B. C. etc.) - 15 grids greater than or equal to 25% of the guideline value of which 3 are greater than or equal to 1000 dpm/100cm (direct). The elevated activity levels are attributed to 2
naturally occurring radioactive material found in the structural material.
l 4.1.8 North Enst Wing ist Floor 4.1.8.1 CAMPS Room - 41 grids indicate greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material. It should be noted that the CAMPS area was constmeted in the mid sixties. Background fluctuations on construction material were similar to those found through out the rest of the facility supporting the argument that many of the areas with elevated readings are i
due to naturally occurring radioactive material found in the structural material.
l 4.1.8.2 Sections /A B. C. etc.) - 74 grids greater than or equal to 25% of the r.,uideline value ofwhich 5 are l
greater than or equal to 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.9 North Enst Wing 2nd Floor 4.1.9.1 Grid Sea / storace area. Owner opened a sealed glass case containing uranium powder spilling the contents. He then used a standard vacuum cleaner to cleanup the spilled powder. Sevenson was requested by the owner to survey the area. I grid was greater than or equal to 3000 dpm/100cm2 (direct). This room was surveyed as an affected area.
4.1.9.2 CAMPS Room - 27 grids greater than or equal to 25% of the guideline value of 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.9.3 Roof-62 grids greater than or equal to 25% of the guideline value of which 7 are greater than or equal to 1000 dpm/100cm (direct). All of the roof areas exhibited elevated activity levels. Samples 2
from the roof, counted on site for informational purposes only, indicated no thorium or uranium contamination. A sample sent for uranium and thorium activity determination indicated no uranium and thorium. It is therefore believed that the roof area as a whole is either contaminated with naturally occurring radioactive material or from fall out from nuclear testing and is beyond the scope of the survey guidelines.
4.1.9.4 Sections /A B. C. etc.) - 66 grids greater than or equal to 25% of the guideline value ofwhich 2 are greater than or equal to 1000 dpm/100cm (direct). 2 grids greater than or equal to 25% of the 2
guideline value of which 1 is greater than or equal to 200 dpm/100cm2 (smearable). These areas were primarily in the grid seal room. The elevated activity levels are attributed to naturally occurring radioactive material found in the structural material.
4.1.10 North West Wing ist Floor 4.1.10.1 Corner - 18 grids greater than or equal to 25% of the guideline value of which 1 is greater than or equal to 1000 dpm/100cm2 (direct). The elevated activity levels are attributed to naturally occurring radioactive material found in the stmetural material.
4.1.10.2 E.o. of-30 grids greater than or equal to 25% of the guideline value of which 5 are greater than or equal to 1000 dpm/100cm (direct). All of the roof areas exhibited elevated activity levels. Samples 2
from the roof, counted on site for informational purposes only, indicated no thorium or uranium contamination. A sample sent for uranium and thorium activity determination indicated no uranium 17
and thorium. It is therefore believed that the roof area as a whole is either contaminated with naturally occurring radioactive material or from fall out from nuclear testing and is beyond the scope of the survey guidelines.
4.2 BACKGROUND
LEVELS Background exposure rates for interior and exterior areas vary based on the material being surveyed.
The background levels are summarized in Table E-1. These represent average readings for each material. It should be noted that background fluctuated within a given material and higher levels can be obtained. Table E-1 does not reflect the maximum reading for each material. The following table is a quick overview of the ranges of background levels. This further emphasizes the large fluctuations in building material. Small rooms or areas where more than one wall was made of material with elevated background readings in close proximity created many of the false readings in excess of the guideline value.
Wing Location Elev.
Mnterial cpm 1
West Bathroom 4
Glazed tile over brick 400 - 1000 North East Bathroom 4
Painted brick 300 - 725 i
Corner j
l West Stairwell 4
Painted brick 350 - 700 West Sections A, B, C etc.
3 Painted brick 350 - 700 West Stairwell 3
Painted brick 425 - 800 South East Floor 2
Concrete 325 - 600 North East Wall 1
Block 275 - 550 North East Wall 1
Brick 275 - 650 4.3 BUILDING SURVEYS l
Scans Scans of surface (Table E-2) identified multiple locations of residual contamination. Table E-5 represents the unaffected surface activity measurements. Table E-6 represents the unaffected smearable activity measurements.
HP technicians scanned to determine if contamination was in excess of the guideline values. Once the guideline values were exceeded the HP would document the results. The HP technicians did not continue to search for the highest level within the grid. The HP technicians returned to the grid and searched for the highest contamination level and performed a direct reading at the location.
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HP technicians performed alpha scans but only annotated readings greater than background. Surveys where alpha scans were performed and no readings logged are less than minimum detectable.
Surface Activity Mensurement Table E-3 presents the results of affected surface activity measurements. Table E-4 presents the results of smearable activity measurements. All individual measurements were within guideline levels, with many of the measurement being below the sensitivity levels of the procedures.
Sampling Tables E-7 contain results of concrete samples from building interior surface. No evidence of sample activity exceeding guidelines was noted. Gamma scans at outside sampling locations did not indicate potential residual activity.
Exposure Rates Summary of exposure rates inside structures ranged from 7 to 15 uR/h (Table E-9). These rates were within the guideline levels of 5 uR/h above background.
4.4 GROUNDS SURVEYS Scans Scans identified 72 locations of elevated contact beta radiation. This is attributed to naturally occurring radioactive material in the tar. (Table E-8). The parking lot areas were surveyed as unaffected.
Exposure Rates Exposure rate measurements are presented in Table E-8. Rates ranged between 7 and 19 uR/h; all locations satisfied the guidelines.
Concentrations In Soil Table E-8 presents results of soil sampling. No samples contained in excess of the uranium or thorium guideline. The corner where the shed and ducting were found was surveyed as affected.
4.5 DATA EVALUATION Tables F-1 summarizes the surface activity measurements. F-2 summarizes the isotopic samples results. Results in excess of 25% of the guideline value require further evaluation through surveys or remediation. See Appendix G for the procedures used to ensure the validity of the characterization and final survey data.
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5-
SUMMARY
Characterization surveys of the former Clevite site were conducted. Results of the survey indicate that large areas of the southwest and west wings require remediation along with small areas on the second l
floor and roof. Sevenson will submit a revised remediation plan to the NRC for approval.
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APPENDIX G QC/QA PROCEDURES 1
BACKGROUND AND SOURCE CHECKS 1.
Initial background levels will be established before work commences per section 5.8 of the manual.
2.
A daily background reading should be made. This reading should fall with in the limits l
established for background.. Ifit is higher there is a possibility the detector may be contaminated or meter is not functioning properly.
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3.
The detection efficiency of the detector should be established initially by taking a series of ten counts and determining the average and the standard deviation at the 95% confidence f
level.
l 4.
A daily source check should be made of the instrument. The value should fall within the established limits. Ifit doesn't, check counting gas, high voltage. Compare against similar detector. If comparison fails, send off for repair.
BUILDING SCAN SURVEY 1.
Select the proper instrument from those listed in Table 2.
2.
Obtain the proper data sheets.
3.
Fillin the heading on the data sheet.
- 4. A. Affected Areas Scan 100% of the floor and lower walls in affected areas. Ifit is believed that contamination levels on the upper walls and ceilings are less than 25% of the guideline a minimum of 30 measurement locations on each surface should be selected. If l
contamination levels are greater than 25% of the guideline value all surfaces shall receive a 100% survey. Record elevated locations of radioactivity.
B, Unaffected Areas Scan 10% of the floor and lower wall surfaces of unaffected areas using a grid system.
5.
Scan speeds will be one detector width per second for beta and alpha panicles and 0.5m/sec for gamma radiation. The detector should be no more than 2 cm off the floor for beta detection and no more than I cm for alpha detection. The gamma probe will be held at the waist.
6.
Locations of elevated radiation will be noted for further investigation.
AVERAGING SURVEY 1.
Select the proper instruments from the list in Table 2. Ensure that the background and source checks have been done.
2.
Obtain the proper survey sheets.
3.
Fillin the data sheet heading.
4.
Determine the area of the elevated reading and record the average activity contained in the area. Take five direct readings in the one meter area that contains the elevated reading and record on the form.
5.
Repeat for each elevated reading in the survey unit.
6.
Turn in the forms to the survey coordinator.
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BUILDING DIRECT MEASUREMENT AND REMOVABLE CONTAMINATION SURVEY 1.
Select the proper instruments from those listed in table 2. Check to see if backgrounds and source checks have been done.
2.
Obtain the proper survey data sheets.
3.
Complete the survey information at the top of the form.
- 4. A. Affected Area Since the meter used for the beta scanning survey has an MDA greater than 25% of the i
guide line the survey will be done at one meter intervals on the floor and lower wall surfaces and at all locations determined to have elevated levels of activity from the scan survey. A direct mc rement on ceilings and upper wall surfaces should be made for each 20 m: of surface area. A scan of each selected location should be made to identify any locations of elevated activity.
B.
Unaffected Area Thirty or 1 per 50 m: direct measurement points, which ever is greater, should be selected in the unaffected area. All surfaces in the survey unit should be included in the total area.
5.
Take a one minute count at each location and record the reading.
Take a 100 cm wipe at each location of the direct survey using moderate pressure. Place 6.
2 the wipe in an envelope labeled with the proper location. If cracks or bolt holes are present use a Q-Tip to obtain a wipe.
7.
Insure that the forms have been completed and turn them and the wipes in to the survey coordinator.
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DATA EVALUATION, AFFECTED AREAS i
For each survey unit file fill out the attached data summary sheet and insert it into the front of the file when it is completed.
CHECK affected Area Surveys for-1.
Completeness of data.
2.
Do elevated areas of activity exceed 3 x guideline ? If so tag file with red tag indicating remediations is needed.
l 3.
If elevated areas of activity fall between one and three guideline values tag the file with a 1
blue tag indicating an averaging survey is required.
f 4.
If external gamma readings are greater than b2 x guidelines tag file with red flag for
{
remediation.
5.
If removable contamination levels are 0.2 x guideline tag with a red tag for remediation.
6 If all the survey points meet the guideline criteria determine the average activity for the survey unit using eq.5.11 from the manual.
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i 7.
Compare the calculated average value to the guideline using eqs. 5.12 & 5.13.
i 8.
If the value for is less than the guideline value the survey unit being tested meets the guideline criteria at a 95% C.L. The file will be tagged with a green flag.
j 9.
If g is greater than the guideline and the average activity level for the survey unit is greater than the guideline tag the file with a red tag.
10.
If the average activity of the survey unit is less than the guideline a larger sample may l
demonstrate compliance. If a larger sample is required the number of samples to be taken may be determined by eq. 5.14. Tag the file with a yellow flag to indicate additional sampling is required. If after sampling the activity levels cannot meet the guideline criteria tag the file with a red tag for remediation.
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12.
If the survey unit meets the criteria in step 8 above calculate the radioactive inventory for the survey unit.
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s DATA EVALUATION, UNAFFECTED AREAS For each survey unit file fill out the attached data summary sheet and insert it into the front of the file when it is completed.
CHECK unaffected Area Surveys for:
1.
' Completeness of data.
2.
Do elevated area of activity exceed 0.25 x guideline ? If so reclassify unit as affected.
3.
If all the survey points meet the guideline criteria determine the average activity for the survey unit using eq.5.11 from the manual.
4.
Compare the calculated average value to the guideline using eqs. 5.12 & 5.13.
5.
If the value for u is less than the guideline value the survey unit being tested meets the guideline criteria at a 95% C.L. The file will be tagged with a green flag.
6.
Ifu is greater than the guideline a larger sample may demonstrate compliance. If a larger sample is needed the number of samples needed can be calculated using eq.5.14. Tag the file with a yellow flag to indicate additional sampling.
7.
If upon additional sampling y is still greater than the guideline reclassify the survey unit as affected.
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DATA
SUMMARY
SHEET 1.
DATE 2.
SURVEY UNIT 3.
INITIAL CLASSIFICATION 4.
NUMBER OF SURVEY POINTS > GUIDELINES A. SCANS B. DIRECT SURVEYS C. EXTERNAL RADIATION D. REMOVABLE CONTAMINATION 5.
NUMBER OF SURVEY POINTS >l AND <3X GLUDELINES 6.
ARE ALL DATA POINTS LESS THAN THE GUIDELINE VALUES IF THE ANSWER TO 6 IS YES 7.
WHAT IS THE AVERAGE LEVEL OF CONTAMINATION FOR THE SURVEY UNIT 8.
STANDARD DEVIATION FOR SURVEY UNIT 9.
g=
10.
> GUIDELINT 11.
IS THE AVERAGE VALUE > THAN THE GUIDELINE (REMEDIATE).
12.
IS THE AVERAGE VALUE < THAN GUIDELINE (TAKE MORE SAMPLES).
13.
HOW MANY MORE SAMPLES MUST BE TAKEN