ML20140B994
| ML20140B994 | |
| Person / Time | |
|---|---|
| Site: | 07000033 |
| Issue date: | 03/20/1997 |
| From: | Bellamy R, Anthony Dimitriadis, Roberts M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20140B985 | List: |
| References | |
| 70-0033-97-01, 70-33-97-1, NUDOCS 9704010569 | |
| Download: ML20140B994 (17) | |
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- l U.S. NUCLEAR REGULATORY COMMISSION i REGION l i
f l INSPECTION REPORT ]
l Reoort No. 070-00033/97-001 Docket No. 070-00033 i License No. SNM-23 J j i Licensee: Texas Instruments, Inc.
i 34 Forest Avenue l
Attleboro, Massachusetts 02703 4
4 Inspection At: Texas Instruments, Inc. I 1 Attiftboro, Massachusetts inspection Conduc ed: , F bbarv 3-6,1997 Inspectors:
dO. D97 Arith Off'n itriadis date '
Health Physicist
$t Mark C. Roberts, CHP
- 0. 0 O f/L 1# li' f 7 i
- date Senior Health Physicist
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l Approved By: M kc 4d 3 20 - 9 f date Jonald R. B/Ilamy, Ph. D., Chief i Decommissioning and Laboratory Branch l Division of Nuclear Materials Safety l l
i Insoection Summarv: Announced, confirmatory survey at the licensee's Attleboro, l Massachusetts facility (Inspection Report No. 070-00033/97-001) l
- l Areas inspected
- Organization and scope of remediation project, confirmatory measurements in interior areas, confirmatory measurements in exterior areas, results of sample analysis, review of radiological survey and remediation documents.
Results: Radiological measurements did not identify any residual levels in excess of l the criteria for release for unrestricted use. Sample results from 40 soil samples !
analyzed in the NRC regional laboratory confirmed the licensee's results. A small amount of contaminated soil or contamination on below-ground concrete surfaces was i
left in place in inaccessible areas that could not be further remediated because of their proximity to vital structures or utilities. Measurements in each of these areas were not different than ambient background measurements. Based on volume averaging, the 3
inspectors determined that the average total uranium concentration in each of these areas is less than 30 picocuries per gram.
9704010569 970320 PDR ADOCK 07000033 C PDR
DETAILS
- 1. Individuals Contacted
- Michael Elliott, Environmental Manager, Texas Instruments, Inc. (TI)
- Francis Veale, Environmental Safety and Health Department Manager, Tl
- James Armstrong, Operational Excellence Manager, TI
- Steve Shafer, Health Physicist (Exterior Remediation Proiact Manager), Roy F.
Weston, Inc. (Weston)
Michael Madonia, Health Physicist (Interior Remediation Project Manager),
Weston (via telephone on February 5,1997)
- Thomas O'Connell, Health Physicist, Commonwealth of Massachusetts
- Denotes those present at exit meeting
- 2. Backaround The Tl facility is located in Attleboro, Massachusetts, approximately 16 k6 meters (10 Miles) northeast of Providence, Rhode Island and 48 kilometers (30 milu) southwest of Boston. The site currently comprises eighteen buildings owned by Tl on approximately 40 hectares (100 acres). Operations with radioactive material began at the site in 1952 when Metals and Controls, Inc. began to fabricate enriched uranium foils. Metals and Controls, Inc., merged with Tl in 1959 and eventually was operated as a corporate division of TI. From 1952 through 1965, Metals and Controls (and later TI), under a variety of government contracts, f abricated enriched uranium fuel elements for the U.S. Naval Reactors Program, U.S. Air Force, other U.S. Government-funded research, and a few commercial customers. From 1965 through 1981, Tl fabricated fuel for the High Flux Isotope Reactor at Oak Ridge National Laboratory and other government-owned research reactors. Depleted uranium and processed natura! uranium were also used at the facility in research and development of the product' . nethodologies. The facility remains operational in a variety of metallurgical production activities; however, radioactive materialis no longer used in the company's manufacturing operations.
Operations with radioactive materials were initially conducted in portions of what is now Building 4, with very limited operations conducted in Building 3. In 1956, Metals and Controls constructed Building 10 on the site to house all work with radioactive materials. By 1957, all manufacturing operations were moved to Poilding 10. Waste handling, processing of scrap metal and residues, and treatment of waste acids and water were conducted in Building 5 and outside Building 5 in areas known as the Metals Recovery Area and the Stockade. A waste evaporator and an incinerator were operated in Building 5/ Metals Recovery Area. Scrap and waste generated in the manufacturing processes were returned to the U. S. Government; however, some materials contaminated with low levels of radioactivity were disposed in a burial site adjacent to Building 11.
Following cessation of operations with radioactive materials in 1981, Tl initiated remediation of uranium contamination in the buildings and surrounding exterior locations. Remediation and final surveys of contaminated portions of Buildings 4 l Inspection Report No. 070-00033/97-001
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l and 10 were completed in 1985 and the NRC staff approved release of these l buildings for unrestricted use. Residual radioactive contamination remained in the burial area east of Building 11 and west of the recently constructed Building 12.
In 1990, the NRC listed the Tl Attleboro, Massachusetts f acility on the NRC Site Decommissioning Management Plan (SDMP) becauce of the presence of the residual contamination in the burial area. Region i staff approved a remediation pian for the burial area in 1992 and initial remediation was completed in Deceraber 1992. A confirmatory survey conducted by the Oak Ridge Institute for Science and Education (ORISE) in December 1992 identified some remaining contamination on the walls of the excavation. In July 1993, the licensee completed additional !
remediation activities. An ORISE confirmatory survey performed in December i 1993 did not identify any remaining residual contamination in this burial area in j excess of the current criteria for release for unrestrictsd use.
i After completion of the remeciation and surve', of the burial area, Tlidentified soil j contamination in three locations within the Netals Recovery Aiea. Remediation I and sampling in this area during 19E ' ::d % tho determination that the three distinct contaminated areas were actudy part of a single, larger contaminated area. Remediation of this area was ec,rnp *ted in November 1994. After I identification of the additional c-mmnire en in the Metals Recovery Area, Region I staff requested that Ti perforrr. a comprehensive survey of all potentially affected areas on the site. These comprehensive radiological surveys, performed in 1994 and 1995, and discussbns vi,- !ong-term employees, led to the identification of additional contaminatec: soF, primarily in the Stockade and Building 12 south lawn area. The contamination in the stockade area was likely due to the past handling and storage operations in the area. Contamination on the lawn of Building 12 was likely the result of intrusion into the burial area and the spread of contamination during final grading around the building. Residual contamination was identified in Buildings 4,5, and 10, primarily where unclad uranium operations had been conducted. The contamination was primarily limited to cracks and joints in the concrete floor, areas around equipment installed in the concrete floor, and drain lines buried in or beneath the concrete floor. Remediation was performed in accordance with the 1992 plan for remediation of the burial area and a 1994 addendum.
Also, in approximately 1978, NRC confirmed the presence of radioactive i contamination at the Shpack landfill in nearby Norton, Massachusetts. The source of this contamination may have been the result of work performed at the Tl i Attleboro facility, but the company has not acknowledged that its facility was the l source of the materialin the landfill. Although some residual radioactive material was removed from the closed landfill, further remediation for both radiological and 4 chemical contaminants may still be required. In 1980, the landfill was listed on the U.S. Department of Energy (DOE) Formerly Utilized Site Remedial Action i Program (FUSRAP), which will manage any remediation of radioactive materials. I In addition, Ti and several other companies have entered into a consent order with the U.S. Environmental Protection Agency (EPA) regarding the landfill.
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Inspection Report No. 070-00033/97-001 l
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- 3. Oraanization and Scooe of Remediation Project
, l The site remediation project was coordinated by the Environmental Manager. This '
individual reports to the Environmental Safety and Health Manager who reports to the Site Manager. The remediation of the Metals Recovery Area was handled as i one separate project and the remediation of the remainder of the exterior areas !
and all of the interior areas was handled as a second separate project. CPS l Environmental, Inc. provided contractor health physics technical support and I directed the excavation and drilling contractors based on the results of the l radiation surveys and sample analysis. CPS, Environmental also performed the I radiological characterization of the site. Roy F. Weston, Inc. provided project management for the remainder of the exterior remediation and the interior remediation. Two Weston project managers provided direct supervision of the support services including health physics, construction, transportation, and analytical services.
I No safoty concerns were identified.
- 4. Instrumentation Used in Confirmatory Survevs The inspectors used a series of portable radiation survey meters and laboratory equipment to make confirmatory measurements. Ambient gamma radiation levels were measured with Ludlum Micro-R meters (NRC # 033513 and NRC # 019634, calibrated on December 5,1996 and March 14,1996, respectively). Unless otherwise indicated, these measurements were made at a distance of one meter j above the ground or from the surface that was measured. Ambient exterior I gamma radiation in the vicinity of the site ranged from 8 - 12 R/ hour. i Background measurements inside Building 10 in unaffected areas ranged from !
10 - 15 pR/ hour. The higher range of values was generally measured in locations j with newer concrete. Direct measurements for radioactive contamination were made at near contact with floor and wall surfaces using Ludlum Model 43-68 100 cm' gas-flow proportional detectors (NRC # 054810 and NRC # 057023) with Ludlum Model 18 rate-meters (NRC # 054822 and NRC # 054825, both calibrated March 4,1996). Floor surfaces were scanned with Ludlum Model 239- l 1F floor monitors (NRC # 054976 and NRC # 054975 equipped with Ludlum Model 2221 scaler / rate-meters (NRC # 054826 and NRC # 054828, both calibrated March "4,1996). The inspectors determined the operating voltages !
and detector effic 'cies prior to the inspection and confirmed the efficiency and ;
measured the back Jound, for each detector, daily prior to initiating confirmatory measurements. The inspectors also measured higher background counts with the gas proportional detectors on the newer concrete. A 2" x 2" sodium iodide detector (Ludlum Model 44-10), coupled to one of the Ludlum Model 18 rate-meters, was used to make gross gamma measurements.
Soil samples from interior and exterior remediated areas were selected from archived samples in storage. Two additional soil samples were obtained directly from areas where characterization measurements indicated that the total uranium Inspection Report No. 070-00033/97-001
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l concentration did not exceed the NRC guidelines for release for unrestricted use.
Each soil sample was prepared for analysis in the Region I radioanalytical laboratory by drying and then milling the dried sample. An aliquot of each sample .
was weighed and transferred into a Marinelli beaker for gamma counting. Gamma I counting was performed using a high-purity germanium detector (HpGe) that can quantify specific gamma emission energies from the sample. Analysis of the gamma spectrum and identification of radioactive isotopes is performed with a commercial software program. Results of the analysis of the soil se.mples were I reported in units of picocuries/ gram (pCi/g) with an uncertainty of one standard ;
deviation for each radionuclide reported.
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- 5. Confirmatorv Measurements in Interior Areas 5.1. Measurements in Buildina 4 ,
I Building 4 is the largest of the manufacturing buildings on the site. A l small portion of the building was used for uranium milling prior to the I construction of Building 10. Approximately 12,000 ft" of this 295,000 ft* I building required remediation. Gamma exposure rate measurements in the l remediated area and in the area adjacent to the remediated area ranged from 6 - 12 pR/ hour. With the exception of one ares, these values were not distinguishable from background measurements in the building. The exposure rate measured along a stone walkway adjacent to the i remediated area was as high as 18 pR/ hour. The source of these slightly elevated readings appeared to be the natural stone used in the walkway.
Scanning and direct measurements were performed with the gas- i proportional detectors over approximately 100 percent of the accessible floor area in the remediated area. A large portion of the area adjacent to the remediated area was also scanned with the same instrumentation. ;
With the exception of the stone walkway, all results were less than approximately 2000 dpm/100 cm 2. The area of the walkway exhiHied i elevated surface measurements, but appeared to be caused by naturally- l occurring radioactive materialin the rock. I The inspectors also performed gamma exposure rate measurements ;
directly above drain pipes buried in or beneath the floor. These pipes had i either been remediated by pressure washing or characterization readings j indicated that contamination levels met the NRC guidance for release. All '
measurements were not different than the background measurements.
No safety concerns were identified.
5.2. Measurements in Buildina 5 l
Building 5 is a small building adjacent to the Metals Recovery Area.
Remediation in Building 5 consisted of remove! of approximately one third of the concrete floor of the building and removing contaminated soil Inspection Report No. 070-00033/97-001
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beneath the floor. Gamma exposure rate measurements in Building 5. ;
. ranged from 12 - 16 R/ hour. All scanning and direct measurements on j l the floor and lower wall surfaces were not distinguishable from ,
i background. Areas that had been remediated and areas where l l characterization data indicated that the surface criteria for release for {
{ unrestricted use was met were both included in the survey of this i building. Because this is a small building, the entire floor surface was '
subject to the scanning measurements. ..
J i No safety concerns were identified.
i 5.3. Measurements in Buildina 10 I
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! Building 10 was the primary location for work with both clad and unciad j licensed materials. The principle area within the building where the unclad 1
! material was used was the northern end of the building. Licensed material l j' use in the remainder of the building was limited to storage and j transportation support for the finished products. Following the remediation of contamination in 1981 and 1982, the building was
- converted to a number of other manufacturing uses. The recent j decommissioning activities required remediation of approximately 40,000
! ft 8of the 168,000 ft building. 8 Most of the remediation performed 1 required the removal and replacement of portions of the concrete slab,
- excavation and disposal of contaminated soil, and pressure washing or j removal of contaminated drain lines.
- Gamma exposure rates measured throughout the building ranged from 6-16 Ribour. The higher values were generally measured in areas l where thers was newer concrete. The inspectors made scanning measurements throughout the remediated area and in the areas bordering 1
- the remediated area with the floor monitor. All areas were well below the j release criterion of 5000 dpm/100 cm*. The inspectors also performed l gamma exposure rate measurements above the concrete slab where drain i j pipes are buried in the floor. The pipes had either been cleaned w l l characterization measurements indicated that remediation was not j
{ required. The gamma exposure rate measurements in these areas were
- not different than those measured throughout the remainder of the ;
j building. !
i i The licensee left residual contamination in place in eight inaccessible !
i locations within the building. These areas are under or adjacent to vital
! structures or heavy equipment and consist of either contaminated soil or I contamination on concrete surfaces. The depth of .hese locations ranges 1 3
from one to 2.5 meters beneath the ficar surface. Dire :t gamma measurements with the 2" x 2" Nal detector at the soit uurfa::e and
! exposure rate measurements with the Micro R-meter in each of these areas were also indistinguishable from background measurements.
, inspection Report No. G70-00033/97-001 I
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l Because Building 10 required the most significant remediation, the inspectors selected a number of archived, post-remediation samples for analysis in the NRC regional laboratory. The results of these analyses are discussed in section 7 of this inspection report. i i
No safety concerns were identified.
- 6. Confirmatory Measurements in Exterior Areas l The inspectors reviewed the characterization and post-remediation radiological survey data for the exterior areas of the Tl site. The sffected exterior area of the site was divided into approximately 300 grid cells,10 meters x 10 meters. A total of 93 of the grid e ls a required remediation by removal of uranium contaminated soilin excess of th. NRC criteria for release for unrestricted use. The inspectors !
made measurements with the 2" x 2" Nal gamma detector and the micro-R meter j throughout the remediated area and in areas where the characterization data indicated that no remediation was required. A'l redings were not different than the background measurements on the site.
In thirteen of the remediated grid cells, at least one post-remediation sample from the grid cell exceeds the NRC unrestricted use criterion of 30 pCilg total uranium. ;
in al. cases, the residual contamination is inaccessible due to the presence of l critical utilities or structures that prevented complete removal of contaminated soil. I This residual contamination is located from one to three meters below the surface of the soi!. The inspectors made measurenients witn the 2" x 2" Ncl gamma detector snd the micro-R meter in each of these grid cells. Measured exposure rates ranged from 10 to 17 R/ hour. The highest reading was measured in the vicinity of a large sub-surf ace concrete structure which appeared to have contributed to the exposure rate. All other readings were not significantly different than local background levels.
I No safety concerns were identified. ;
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- 7. Results of Samole Analyse _t As discussed in section 4 of this report, selected soil samples, primarily post-remediation samples, were analyzed by gamma spectrometry in the Region l l analyticallaboratory. Concentrations of uranium-235 and U-238 (reported as the l concentrations of the thorium-234 and protactinium-234m decay progeny) for the forty soil samples are presented in Table 1. Because the gamma spectrometry ;
analysis can not be used to quantify the uranium-234 concentration in a sample, l some of the soil samples were submitted to ORISE, the NRC's contractor l laboratmy, foi alpha spectrometry analysis. The alpha spectrometry analysis ,
I prov;ded a cuantitative measure of the U-235 and U-238 concentrations, as well as, the U-234 concentration. Results of the nine alpha spectrometry analyses are presented in Table 2. Licensee contractor data for these samples is also presented in Table 2.
Inspection Report No. 070-00033/97-001
i l The results of the gamma spectrometry analyses confirm that the facility meets l the criteria for release for unrestricted use. The average total uranium concentration of the thirty-nine post remediation samples is approximately 11 pCi/g. The inspectors estimated tk U-234 concentrations using ratios of U-238 to U-235 for each sample. One prr remediation sample indicated a total uranium concentration of approximately 18U pCi/g. This value was in good agreement with the licensee contractor value of approximately 200 pCi/g. The area was later I remediated to levels less than 30 pCi/g. Only two samples indicated estimated total uranium concentrations above 30 pCi/g. One sample from the Metals Recovery Area was approximately 31 pCi/g and appeared to be depleted uranium (the NRC guideline for depleted uranium is 35 pCi/g). A sample from the stockede area indicated an estimated concentration of 38 pCilg. This value was in good agreement with the licensee's contractor values of 36,15 and 45 pCi/g for this location. Although this value exceeded 30 pCi/g, volume averaging indicates that the total uranium concentration in this area meets the 30 pCi/g guideline.
The alpha spectrometry results in Table 2 show very good agreement with data from the licensee's contractors. Except for one sample from the Metals Recovery Area, the data also show very good agreement with the gamma spectrometry data. The disagreement in the sample data from the Metals Recovery Area was likely caused by a non-homogenous sample, because neither the U-235 nor the U-238 results are in agreement, and the alpha spectrometry analysis use a very small sample compared to the gamma spectrometry analysis. One sample from the Stockade Area slightly exceeded 30 pCi/g; however, this area also meets the I NRC criteria based upon volume averaging for the grid cell.
No safety concerns were identified, i i
- 8. Review of Radiolooical Survev and Remediation Documents 1 1
8.1 Survevs of Ooon Land Areas Because of the discovery of soil contamination in the burial area between Buildings 11 and 12 and the subsequent identification of soil l contamination in the Metals Recovery Area adjacent to Building 5, Tl l conducted a comprehensive survey of exterior areas of the site. This systematic characterization survey of the affected and unaffected exterior areas of the site was conducted from July through September 1994 and was documented in a May 1995 report (Radiological Surveys of Open Land Areas, Texas instruments incorporated, Attleboro, Massachusetts).
The survey included a 100 percent walkover survey of both the affected and unaffected areas of the site using a 2" x 2" Nal detector and rate-meter. The surveys were conducted by CPS, a contractor for TI.
Undeveloped portions of the site were not surveyed.
l Systematic surface and sub-surface soil samples were taken by a split spoon sampling apparatus and drill rig. Sampling was conducted at 1600 Inspection Report No. 070-00033/97-001
l> cations resulting in the collection of 5865 surface and sub-surface soil samples. Sample locations in affected areas were defined on a 10 meter x 10 meter (100 m') grid plan to ensure complete coverage of the affected ai9a. Sampling in the Stockade Area was complicated by the presence of numerous underground electrical, communication, and water utilities and concrete supports for overhead structures. Designated sample points within some of the grid cells were moved short distances to avoid these obstacles. Unaffected areas were not sampled on a defined grid; however, thirty random sub-surface samples were collected in the unaffected areas. Samples were evaluated by the gross alpha soil analysis technique to identify total uranium concentrations. The soil sampling in the affected area identified eighty-five 100 meter2 grid cells where soil contamination exceaded NRC guidelines for release for I unrestricted use. One additional contaminated area was found in the ]
unaffected area survey. This area, which bordered the Stockade Area, ,
was remediated as part of the exterior remediation project in the Stockade !
Area. !
Based on a review of the data in the characterization report, knowledge of the physical layout of the site obtained in previous inspections, and a prior review of the gross alphe counting technique (including the analysis of )
samples split with the NRC), the site was adequately characterized to l identify loations where licensed material was used or may have been inadvertently iisoosed. Tl's contrsctors and environmental staff l interviewed a xmber of long-time employees to assist in determining the l areas that wero defined as affected.
No safety concerns were identified.
8.2 Remediation of the Metals Recoverv Area Radiological surveys in late 1993 and early 1994 identified soil contamination in the Metals Recovery Area. This area was formerly a waste handling area where an incinerator and a liquid waste evaporator were operated. Three initial areas were identified in this area and the contaminated soit volume was estimated to be approximately 425 m' (15,000 ft'). The remediation activities conducted in this area led eventually to the disposal of 3300 m' (115,000 ft') of contaminated soil.
Contamination was primarily limited to the top 15 cm of soil; however, excavation of contaminated soil down to approximately 2 meters was required in the area immediately adjacent to Building 5. The highest concentration of uranium identified in characterization and remediation samples was 17,000 pCi/g. Remediation activities were conducted from April 1994 through November 1994. A report summarizing the results of the remediation of the Metals Recovery Area was transmitted to the NRC in October 1996 (Texas instruments Incorporated, Attleboro, Massachusetts - Remediation of the Metals Recovery Area, Final Report).
Inspection Report No. 070-00033/97-001
The results from the analysis of systematic surface and sub-surface soil samples from the excavated area and the perimeter of the excavated area; and exposure rate measurements indicate that the criterion for residual uranium concentration in soil (30 pCi/g) and the exposure rate criterion were both met. In one 9 meter x 9 meter grid cell, contaminated soil averaging 49 pCi/g total uranium was left in place around an electrical duct bank. Using a volumetric averaging method, the inspectors determined that this area was below the 30 pCi/g *otal uranium criterion when averaged over a one-meter thick vertical pia n. Rain water that collected in the excavation was confirmed to be well below effluent criteria and was released. Contaminated soil was disposed at the Envirocare facility in Utah.
No safety concerns were identified.
8.3 Remediation of Exterior Areas Adiacent to Buildinas 11 & 12 TI's contractor, Weston, coordinated the remediation of the exterior areas adjacent to Buildings 11 and 12 that were identified in the report on the Survey of the Open Land Areas. The burial area between Buildings 11 and 12 and the Metals Recovery Area were not included in this remediation project because they had been previously remediated by CPS and the results provided to Region 1. Characterization data generated by CPS was used to identify the initial 77,10 meter x 10 meter grid cells, requiring remediation. An additional 16 cells, adjacent to remediated cells, were eventually included in the remediation. The depth of the contaminated material ranged from the surface to approximately three meters (ten feet). Remediation activities on these exterior areas were conducted from June 1995 through December 1995. The results of the remediation activities were documented in an August 1996 report (Texas Instruments Incorporated, Attleboro, Massachusetts - Remediation of Exterior Areas Adjacent to Buildings 11 and 12, Final Report).
Remediation of contaminated soilin grid cells was accomplished by removing soilin approximately 30-centimeter (one-foot) sections within the grid cell. In areas where the surface soil was less than the criteria for release for unrestricted use, the soil was reserved for backfilling excavated areas where contaminated soil was removed. Contaminated soil was excavated and segregated for eventual disposal. Excavation continued until field measurements indicated that the unrestricted guidelines had been met. Thirteen check samples were then analyzed using a gross alpha screening technique. If the results of those analyses were acceptable, five verification samples (one from each quadrant of the cell and one from the center of the cell) were collected and analyzed and reported as the final verification sample. A composite of these samples was then sent to an off-site vendor for alpha spectrometry analysis.
Inspection Report No. 070-00033/97-001
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Contaminated soilin excess of the NRC guidelines for release for unrestricted use was left in place in a few inaccessible locations. These ]
areas are beneath vital structures or utilities and can not be further ;
remediated without adversely affecting the structures. In all but three !
areas, the average total uranium soil concentration on the surface of the I excavation met the averaging criteria for unrestricted use. In the other three locations, using a volumetric averaging method, the inspectors determined that these areas Nsu met the 30 pCi/g release criteria.
1 No safety concerns were identified.
l 8.4 Surveys of Interior Areas in Buildinas 4,5 and 10 Tl's contractor, Weston, also coordinated the remediation of the ;
contaminated interior portions of Buildings 4,5, and 10. Remediation i activities on these interior areas were conducted from June 1995 through September 1996. The results of the remediation activities are i documented in an October 1996 report (Texas Instruments incorporated, l Attleboro, Massachusetts - Remediation of Building Interiors, Buildings 4, )
5, and 10). l The contaminated portions of the buildings were divided into eighteen (decontamination) areas based upon physical barriers and historical l operations. The decontamination areas were further divided into 100 m 2 ;
grids. A contaminated portion of the roof was similarly divided. I Remediation activities primarily included scabbling contaminated concrete floors and removing portions of the concrete slab to excavate contaminated soil and remove contaminated drain lines. The total volume of waste disposed from the interior remediation project was 980 m*
l (34,600 ft'). Final remediation soil samples were analyzed by an off-site i laboratory for total uranium or isotopic uranium. Surface contamination I measurements were performed with properly calibrated detectors with sufficient sensitivity to meet the NRC guidelines for surface contamination measurements.
i Contaminated soil or surface contamination in excess of the NRC l guidelines for release for unrestricted use was left in place in a few inaccessible locations. These areas are beneath structural column ;
footings or under vital machinery and can not be further remediated '
without adversely affecting the building structure or some of the machinery in the building. In these locations, using a volumetric averaging ;
method, the inspectors determined that these areas meet the 30 pCi/g i release criteria. All other areas were also sufficiently remediated to meet the NRC criteria for release for unrestricted use. ;
Based on their review of this document, the inspectors requested additional information concerning the remediation activities for pipes left in inspection Report No. 070-00033/97-001
place and the evaluation of residual contamination. The inspector also requested that the licensee perform a dose evaluation of the residual contamination in the remediated drain lines. Based on the review of three documents prepared by Weston (Texas instruments Incorporated Attleboro Facility - Building Interiors Remediation, Drainage System Characterization, January 1996; Drainage System Unrestricted Release Information -
Supplemental Analyses, February 11,1997; and SNM License Termination Hypothetical Radiological Dose and Exposure Rate Assessment, Priority 2 Drain Lines), the inspectors concluded that the residual activity in the priority 2 drain lines (drain lines that were cleaned by pressure washing) met the NRC guidelines for release for unrestricted use.
No safety concerns were identified.
8.5 Syrvevs of Buildina Interiors. Overhead Structures. and Uooer Walls As part of the characterizction of the affected buildings, surveys of the building interiors, overhead structures, and upper walls were performed.
Although data from these surveys were recorded, the surveys were not initially documented in a report. The results of the surveys were used to cuide the remediation of contaminated portions of Buildings 4 and 10.
The surveys were subsequently documented in a February 1997 report (Texas Instruments incorporated, Attleboro, Massachusetts -
Supplemental Surveys of Building Interiors, Overhead Structures and Upper Walls). Measurements included both direct measurements to evaluate non-removable contamination and smears to evaluate removable ,
contamination. A review of this document confirmed that the upper l portions of Buildings 3,4,10, and 11 meet the NRC guidelines for release !
for unrestricted use.
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No safety concerns were identified.
8.6 Groundwater Radiolooical Monitorina Data Report I The chemical forms of uranium used at the site were primarily uranium oxides, uranium metal, and uranium metal alloys. These forms of uranium are generally not soluble. Groundwater monitoring data for the Texas l Instrument site is summarized in a letter report (February 24,1997 letter and four attachments to M. Roberts, NRC Region I from M. Elliott, Texas Instruments). Groundwater samples were collected from a series of !
representative monitoring wells on the site during January-March 1993, August-September 1995, and December-February 1996-1997. Gross ,
alpha concentrations for the most recent samples ranged from Mss than I detectable to 11 pCi/ liter and gross beta concentrations ranged from less than detectable to 25 pCi/ liter. These values are below the EPA '
groundwater screening criteria for gross e,"ha and gioss beta activity of 15 and 50 pCi/ liter respectively. Results from ti c earlier samples were s
Inspection Report No. 070-00033/97-001
, less than the most recent samples. A specific uranium analysis was performed on selected samples in the recent sampling period. Measured total uranium concentrations ranged from 0.22 to 0.39 pCi/ liter. These concentrations are below the EPA proposed primary drinking water limit of 30 pCi/ liter for uranium, and are acceptable for releasing the site for unrestricted use.
No safety concerns were identified.
8.7 Dose Assessment As discussed in sections 8.4 and 8.b, residual contamination was left in piace in areas that were inaccessible because the remaining material was beneath critical utilities and structures. In order to conclude that there is no significant dose impact in leaving this materialin place, and in order to satisfy the Commonwealth of Massachusetts requirement that the residual dose impact be less than 10 millirem per year, TI's contractor (Weston) performed a supplementary Radiological Dose Assessment of the interior !
and exterior areas. The results of this assessment are reported in a l February 20,1997 report (Texas Instruments, Incorporated - SNM License Termination, Radiologica: Dose Assessment). The assessment considered both a current exposure scenario and a future exposure scenario for members of the public. Ir; each case, a maximum population group is considered.
The current exposure scenario was intrusion of a Texas instruments' maintenance worker into any of the five primary source areas to perform maintenance in a trench. This scenario considers multiple exposure pathways including direct radiation exposure, inhalation of resuspended dusts and ingestion of co aa,qinated soils. For conservatism, the area of I highest residual contar,iination was used as the source term. The maintenance worker i'itrusion scenario resulted in an annual total effective dose equivalent of 1.3 millirem. The dose calculation was performed using a series of hand calculations. The contractor considered using the RESRAD-BUILD computer code for the calculations, but determined that the program was not readily applicable to the scenario.
The future use scenario considered closure of the site, removal of the industrial buildings and construction of a residence. The computer code RESRAD (version 5.62) was used to model the exposure pathways and calculate the dose from the scenario. The area with the highest average residual activity was selected for the calculations. The annual total effective dose equivalent for the future use residential scenario is 7.3 millirem for the first year, with the projected dose declining in future years.
No safety concerns were identified.
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- 9. Exit Meetina The results of the inspection were discussed with the individuals identified in Section 1 of this report.
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l Inspection Report No. 070-00033/97-001
l TABLE 1 1
GAMMA SPECTROMETRY RESULTS OF SELECTED TEXAS INSTRUMENTS, INC., SOIL SAMPLES
[Results in Units of pCi/g dry lo]
Sample Identification Number location Description Th-234 Pa-234m U-235 40S 130E 120195,VER4092C Building 11 West Lawn 1.33 i 0.10 1.0 i 0.6 0.38 i 0.02 30S 130E 120195, VER 0077C Building 11 West Lawn 1.45 i 0.09 1.0 i 0.6 1.13 i 0.03 20S 40E 112995, VER-0103 Stockade Area 7.4 i 0.3 9.1 i 0.9 1.05 i 0.04 01104-6C-SS-01-00 Tl 287 Building 10, Area 6 2.0 i 0.3 4.4 i 1.0 0.43 i 0.04 0110-06-SC-SS-024-00 TI-278 Building 10, Area 6 4.88 0.12 5.0 1 0.8 0.39 i 0.02 1214-12-6D-BSS(substation) TI- Building 10, Area 12 101.8 i 0.7 111 i 2 3.21 i 0.06 359*
01222-13-2C-SS-01-0640 TI-359 Building 4, Area 13 0.4 i 0.3 <2 < 0.1 011046-5C-SS-03-06-00 TI-279 Building 10, Area 6 5.99 i 0.11 6.7 i 0.6 0.58 i 0.03 i
0110-06-60-SS-Ol&-00 TI-289 Building 10, Area 6 < 0.5 1.210.7 0.04 i 0.02 102648-6B-SS-02-06-00 TI-062 Stockade Area 0.67 i 0.09 1.3 i 0.8 0.12 i 0.02 120N210E-09089S-VER4022C Adjacent to Building 12, 3.0 i 0.2 2.5 i 0.7 0.1310.03 Loading Dock 60S 70E-10209S-VER4041-C Stockade Area 11.55 i 0.11 11.3 i 0.8 0.29 i 0.02 100N 150E-092695-VER-0015-Ca Building 11. East Lawn 2.1 i 0.3 3.6 i 0.9 0.08 i 0.03 2050-Il2195-VER-0076-C Stockade Area, near metals p 2.16 i 0.08 2.3 i 0.6 0.73 i 0.02 1
200N 150E-073195-VER-0001-C Building 12, Northwest Lawn 10.7 i 0.4 12.1 i 0.8 0.49 i 0.03 110N 270E-082845-VER-0019-C Building 12, South Lawn 1.54 i 0.11 1.3 i 0.7 0.10 i 0.02 60S 40E-112895-VER-0061-C Stockade Area 4.3 i 0.3 5.7 0.8 0.25 i 0.03 40S 140E 120195-VER-0093-C Building II, Lawn 1.45 i 0.14 2.0 i 1.0 0.48 i 0.03 30S 40E 111495-VER-0064-C Stockade Area 1.1 i 0.3 2.3 i 0.6 0.1410.03 110N 220E491295-VER-0027-C Adjacent to Building 12 Loading 5.55 i 0.09 5.2 i 0.7 0.26 i 0.02 Dock 305 90E 1200195-VER4052 Stockade Area 17.61 i 0.13 18.7 i 0.8 0.64 i 0.03 40S 130E-120492-VER-0092-Cl3 Building 11, West Lawn 1.0 i 0.3 1.4 i 0.7 0.16 i 0.03 20S 90E-120295-VER-0053-C Stockade Area 13.60 i 0.12 13.7 i 0.9 0.58 i 0.03 FGS 20S X90W TI-B5-FGC- Metals Recovery Area 2.54 i 0.10 2.3 i 0.6 0.16 i 0.02 0719-1676 FSG 75SX0 l' TI-B5-FGC-0805- Metals Recovery Area 6.76 i 0.13 4.6 i 0.7 0.4510.03 1744 l
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, Sample Identification Number 1mation Description Th-234 Pa-234m U-235 !
70N X110W 7-2-94 TI-B5-FGC- Metals Recovery Area 0.1610.13 1.3 i 1.2 0.44 i 0.04 0702-1670 i
i 68N X105W 7/1/94 TI-B5-FGC- Metals Recovery Area <1 <4 0.2210.08 2 0701-1659 40S X35W 6* FGS TI-B5-FGC- Metals Recovery Area 1.04 i 0.11 2.2 1 0.6 0.0610.02 .
j 0805-1764 l l l 1 0119-14A-3F-SS 03-06-00 TI-330 Building 4. Area 14 0.Si0.3 <2 0.0710.03 I
1130-12-6E-SS 01-06-00 T1-191 Building 10, Area 12 0.9 i 0.3 1.8 i 0.7 0.1010.03 I
t 121112-5F-BSS South Composite Building 10, Area 12 0.8 i 0.3 <2 0.1110.03 I 0227-BLDG 5-SS-02-06-00 TI-465 Building 5 1.6710.12 1.910.7 0.36i0.03
$ 0111-05-5B-SS-03-06 00 TI-293 Building 10 Area 5 2.61 i 0.11 2.2 1 0.7 0.3310.02 j 0111-05-6B-SS-0446-00 TI-292 Building 10, Area 5 5.910.3 6.910.9 1.10i0.04 0104-12-5D-SS43 06-00 TI-273 Building 10, Area 12 4.3410.08 4.2 i 0.7 0.42 i 0.03 )
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, 0104-12-5E-SS-0246-00 TI-272 Building 10, Area 12 17.63i0.13 18.410.9 0.54 i 0.02 i j 0110-06-6C-SS44 06-00 TI-288 Building 10, Area 6 5.88 i 0.09 5.910.7 0.61 i 0.02 1026-08-7B-SS 01-06-00 Building 10, Area 8 0.410.3 <2 0.08 i 0.03 i
Building 12 Building 12 Lawn 1.2110.11 1.010.7 0.06 i 0.02 l
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! Site Background East of Building 12 0.72 i 0.08 1.1 i0.8 0.0910.02 i
! m Pre-remediation sample 4
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Report No. 070-00033/97-001
TABLE 2 COMPARISON OF ALPHA SPECTROMETRY RESULTS OF SELECTED TEXAS INSTRUMENTS, INC., SAMPLES ,
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[ Results in Units of pCi/g dry i 2a] .
Texas Inst. Licensee Contractor Results NRC Contractor Results Sample Identification No. In-house Results U-234 U-235 U-238 U-234 U-235 U-238 (Total Uranium) 20S 40E I12995, VER-0103 24 (1) 27.71 i 6.62 1.1210.46 7.16 i 1.54 29.1 i 2.1 1.3 i 0.2 8.6 i 0.7 011046-6C-SS-01-00 Tl 287 (2) 5.7911.22 0.29 i 0.20 2.69 i 0.69 8.3 i 0.5 0 3 i 0.06 2.1 i 0.2 0110-06-SC-SS 02-06-00 TI-278 (2) 4.97 i 1.25 033 i 0.27 2.76 i 0.83 10.4 i 0.6 0.52 i 0.07 5.1 i 03 0110-06-SC-SS-03-06-00 TI-279 (2) 1034 i 2.11 0.34 i 0.21 6.06 i 133 16.210.9 0.67 i 0.08 6.9 i 0.4 60S 70E-102095-VER-0041-C 9 5.2 i 1.6 0.51 i 0.28 12.2 i 3.4 5.2 i 03 0.42 i 0.07 13.3 i 0.8 i 100N 150E-092695-VER-0015-Ca 26 2.5 i 0.89 0.07 i 0.10 2.10 i 0.76 2.8 i 0.2 0.14 i 0.04 23 i 0.2 20S0-112195-VER-0076-C 21 8.7 i 033 0.4010.22 8.5 i 0.32 14 3 i 0.8 0.56 i 0.08 1.6 i 0.1 FSG 75SXO l' TI-B5-FGC-0805-1744 30 (3) (3) (3) 16.7 i 1.0 0.77 0.09 8.1 i 0.5 70N XI10W 7-2-94 TI-B5-FGC-0702-1670 10 (3) (3) (3) I1.0 i 0.7 0.42 i 0.07 033 i 0.06 (1) Uncertainty for In-house result not calculated (2) Only alpha spectrometry analysis performed on these samples by the licensee (3) Alpha spectrometry analysis not performed on these samples by the licensee contractor i
Inspection Report No. 070-00033/97-001 ;
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