ML20203C308
| ML20203C308 | |
| Person / Time | |
|---|---|
| Site: | 07000734 |
| Issue date: | 02/05/1999 |
| From: | Gonzales L, Maschka P, Ramirez E GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER |
| To: | |
| Shared Package | |
| ML20203C305 | List: |
| References | |
| PROC-990205, NUDOCS 9902110350 | |
| Download: ML20203C308 (55) | |
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FINAL RADIOLOGICAL SURVEY
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OF GENERAL ATOMICS' BUIL9ING 9 ROOM 049 B
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(Stage 3 of Former " Hot Suite Area")
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Prepared By: Laura Gonzales, Efraim Ramirez, and Paul Maschka Survey Maps: Stephen Finchum February 05,1999 l
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TABLR OF CONTENTS l
4 LIST OF ATTACHMENTS............................................. ii INTRODUCTION............................................................ 1 StrE DESCRIPTION......................................................... i HISTORICAL OVERVIEW OF PROCESSING ACTIVITIES.............,........... 2 TARGET CRITERIA FOR RELEASE TO UNRESTRICTED USE..................... 3 RADIATION DETECTION EQUIPMENT........................................ 3 i
CHARACTERIZATION SURVEYS............................................. 4 j
DECONTAMINATION METHODS............................................. 4 i
FINAL RADIATION SURVEYS................................................ 3 COMPLIANCE WITH TARGET CRITERIA...................................... 6 CONCLUS ION.............................................................. 7 REFERENCES.............................................................
8 SURVEY PLANS CHARACTERIZATION SURVEY PLAN............................ APPENDIX A FINAL SURVEY PLAN........................................... APPENDIX B CONFIRMATORY SURVEY PLAN................................ APPENDIX C i
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LTRT OF ATTACHMFNTS
( : Plan View of General Atomics Site................................. : First Floor layout of Experimental Building 9 showing the previous location
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of the " Hot S uite" area........................................... : Cunent Configuration ofFormer " Hot Suite" Area..................... 12 : The Former " Hot Suite" Area.............................. : Decontamination Stages for the " Hot Suite" area...................... 14 : Table 1. USNRC's Acceptable Surface Contamination Level............ 15 : Table 2. State of CA Acceptable Surface Contamination Levels!......... 16 : Table 3. List ofInstruments.................................
[ : Table 4. Background Measuremnts and MDA's....................... 18 0: Initial Scan Survey of Stage 3 Room 09-049.......................... 19 1: Characteriration Scan Survey of Concrete Floor....................... 20 2: Table 5. Stage 3 Final Survey Results............................... 21 3: Final Beta & Alpha Scan Surveys and Soil & Paint Samples of Stage 3.... 22 4: Final Survey of Stage 3 - 2 Minute Fixed and Exposure Rate Measurements 23
( 5: Final Removable Contamination Survey of Stage 3.................... 24 6: Table 6. Soil and Paint Samples from Room 049B*................... 25 7: Uranium Isotopic Analysis Results from Room 049 (Stage 3)............. 26
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1 Introduction Until April 1975, General Atomics (GA) conducted TRIGA Fuel Fabrication activitier. licensed by the U.S. Nuclear Regulatory Commission (NRC) in a portion of GA's Experimental Building
- 9. An area in the northwest corner of the building was then known as the " Hot Suite" area (see Artschment 4). TRIGA Fuel Fabrication activities were moved in April 1975 to a new facility at
. Genera! Atomics (i.e. Building 22).
Decontamination of the " Hot Suite" area began in April 1975 and continued until around July 1975. The area was decontaminated to allow for nonradi:nctive use but was not " officially" released by NRC or the State ofCalifomia to unrestricted use. Radioactive material was still being used in selected areas of the building.
Beginning in October 1986, GA decontaminated its Experimental Building 9, except for the " Hot Suite" area. The principle radioactive contaminant encountered was natural thorium, therefore GA submitted a report dated July 28,1987 to the State of California (Reference 1) requesting the release of this building to unrestricted use. This report and request included a former " Pilot Plant" area, but did not include the " Hot Suite" area which was occupied by GA's telecommunication group at that tune.
i After confirmatory surveys were completed and the building was found to meet the release criteria, the State of California released GA's Building 9, except for the " Hot Suite Area", to unrestricted use (Amendment #86 of GA's Radioactive Materials License #0145-80, Reference 2). The NRC also released the building, with the exception of the small " Hot Suite" area where certain TRIGA Fuel Fabrication activities had been located, to unrestricted use on October 1, l
1988 (Reference 3) after compleGon of confirmatory surveys. Please note: not allportions of the area referred to as the ' Ifor Suite" involved the use ofradioactive materials.
In the late 1980's, GA concluded that it had no plans for conducting any future activities involving radioactive materials in the " Hot Suite" area of the Experimental Building 9 (or any other portion' of the building) and would like to obtain the release of the area to unrestricted use.
However, since it was not feasible to move the telecommunications equipment and other activities all at the same time, GA surveyed and pursued the release of the " Hot Suite" area in L
three (3) stages (see Attachment 5).
Stages 1 and 2 were decontaminated in 1988-1989 and have been released to unrestricted use by both the NRC and State of California (references 4 and 5). Stage 3, comprised of only one room (Room 049 B) containing telecommunications equipment, has not been officially released and is the subject of this report.
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Site Description L
The location of the Experimental Building (Building 9) with respect to other facilities on the GA
- Site is shown in Attachment 1. A layout of the Building showing the location of the former " Hot 3
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f Suite" area is shown in Attachment 2.
GA subsequently reconfigured the former " Hot Suite" area. Therefore, room numbers differ from Stage 1 and 2 reports. Attachment 3 shotvs the current configuration of the rooms which
. now occupy the former " Hot Suite" area. Attachment 4 shows the " Hot Suite" area as it existed when TRIGA Fuel Fabrication activities were conducted there. Attachment 5 shows how the
" Hot Suite" area was divided into three (3)" stages". A comparison of the drawings reveals that some of the original walls of the " Hot Suite" area were removed during the reconstruction of the area and new walls were installed. All previous " Hot Suite" areas, except the area associated with Stage 3 (i.e., Room 049 B) were included in the final release surveys of Stages 1 and 2.
Stage 3 (currently Room 049 B) occupies ~569 ft' and is located in the area formerly occupied by: 1) the southem portion of the former " Hot Machine Shop",2) a small strip along the northern end of the former " Melt Room", and 3) the hallway between the fonner " Hot Machine Shop" and the " Melt Room".
f' Historical Overview of Processing Activities The former Hot Suite's existence began in 1958 primarily for the research, development, and manufacturing of TRIGA fuel elements in accordance with NRC (previously AEC) licenses SNM-69 and SNM-696. This work involved primarily the use of 20% enriched uranium (U-235). A review ofpast Work Authorizations revealed that it was also used for small test runs ofprototype and non-TRIGA reactor fuel using mostly depleted uranium. In addition, a batch of fuel was fabricated for the Massachusetts Institute of Technology using " normal" uranium.
A new TRIGA Fuel Fabrication Facility was subsequently constructed at General Atomics, and in April 1975, transfer of usable equipment from the " Hot Suite" to the new building began. In May 1975, contaminated components were mnoved from the Hot Suite and disposed of as contaminated waste and facility decontamination efforts began. The building was then decontan-inated to very low levels; less than 500 counts per minute alpha fixed contamination (measurements were made on a grid with a portable alpha counter) and less than 20 dpm/100 cm2 removable contamination.
Thecu Tent room 049 B (Stage 3) was then used to house the telecommunications equipment for the entire GA site. This equipment was removed fmm Room 049 B in December 1997. Since that time the room has been decontaminated and a Final Radiological Survey perfonned. The results of that survey are the subject of this report.
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Target Criteria For Unrestricted Release l
Surface Contaminatinn Table 1 & 2 (Attachments 6 and 7) are taken from USNRC's and State of Califomia's criteria for releasing facilities and equipment to unrestricted use, respectively. These criteria are incorporated into GA's SNM-6% license and State of California #0145-37 license. These -
l approved guidelines are for surface contamination. The limits in this table were used for
. releasing concrete and other surfaces at the facility to unrestricted use.
Snil Cnntaminatinn.
GA's Site Decommissioning Plan specifies the approved release limits for soil samples that l
contain enriched uranium. The approved total enriched uranium concentration limit is 30 pCi/g.
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Radiation Detection Equipment is a list of radiation detection instruments employed for all surveys performed at Building 9 Room 049B (Stage 3).
Count-rate meters / detectors were calibrated a minimum ofonce every six months and dose-rate '
meters quarterly.
The final survey results have been converted from epm (counts per minute), for each detector, to dpm/100 cm in the data tables by correcting the counts per minute observed by appropriate 2
detector readings for background, detector efTiciency and geometric factors associated with the instrumentation.
nachrnund-A " standard" natural background was determined for each type of detector and surface and subtracted from the survey readings. Background measurements were obtained from GA's Building 13 (no history ofradioactive use). See Attachment 9 - Table 4.
FfYiciency - Portable beta / gamma (GM) and alpha counters were calibrated to determine their efficiencies for uranium after analyses of samples of contaminated concrete from the Stage 3 areas showed uranium contamination (the U-235 enrichment was ~ 3%).
Genmetric conburation-434 cm alpha and beta detectors were used to scan floor and walls.
2 100 cm beta detector was used to obtain fixed measurements.15 cm GM probe & 50 cm alpha 2
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detector were used to frisk cracks, corners, and " hot spots".
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Characterization Surveys L
- A copy of Room 049B Characterization Plan (before tile removal) and the Characterization Plan for the concrete floor (after tile removal) can be found in Appendix A.
In December 1997, the telecommunications equipment was removed from Room 049B, and transferred to one of the rooms in the Stage I area which has already been released to unrest to allow Health Physics access to conduct decontamination activities and radiological surveys i room.
On January 5,1998, initial surveys of the false floor and cables underneath were performed uj hand held probes and masslin wipes; no contamination was detected. The tile over the original
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concrete floor was 60% accessible (due to the false floor). The tile was scanned 100% for a and p contamination. No contamination was detected. However, alpha contamination was detected on a 2
small 200 cm area of exposed concrete near the center of the room (see Attachment 10).
The Characterization Survey Plan for Room 049B was completed on February 23,1998, after the false floor and cables were surveyed and removed from the room. Contamination was found on a majority of floor surfaces and up 1 meter on the West wall. Concrete samples were taken from i
exposed areas where contamination levels were the highest. These samples were analyzed to determine U-235 enrichment. The results can be found in Attachment 17.
Decontamination Methods The following contamination levels existed in Room 049B prior to decontamination:
Survey Floor (concrete)
W Wall (plaster)
Cracks (concrete)
Floor (til 2
Fixed p /100 cm 1237 cpm 1240 cpm B scan /100 cm2 440 cpm 2
scan / 434 cm 2015 cpm 2100 cpm 1150 cpm Fixed a / 434 cm2 350 cpm a scan / 50 cm' 140 cpm 140 cpm a scan / 434 cm2 190 cpm 28 cpm Note: Maximum readingsfor allscans.
l On May 16,1998, an asbestos abatement company removed the tile and approximately 50% of the l
mastic from Room 049B. The tile and mastic was placed in an LSA box and transferred to the GA Nuclear Waste Processing Facility on May 27,1998.
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1 On June 15,1998 a "Blastrak" unit was used to remove the remaining mastic on the concrete floor The "Blastrak" unit also removed some contaminated concrete (~V8" down to ~%" ). A post-d survey of the floor was completed on June 18,1998. The survey showed that both a&p contamination was still present in the corners, alog the walls, and in the cracks where the "blastrac" couldn't reach. See Attachment 11. Additional decontamination with a needle gun and ajack-j hammer was required, Decontamination of Room 049B was completed on July 29,1998.
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Final Radiation Surveys t
Table 5 (Attachment 12) provides results of the Final Survey conducted in Room 049B. The measurements of contamination (in dpm/100 cm ) were averaged over 1 m area or less. The maximum 5
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contamination level (also in dpm/100 cm ) applies to an area ofnot more than 100 cm. The final floor 2
2 and wall survey locations and details are provided in Attachments 8,9, and 10.
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A copy of the Final Survey Plan is provided in Appendix B. Additional readings and wipes were obtained for most surveys.
Fynosure rate measurements The Final Survey shows measurements were taken on contact and at one meter in 29 locations. The maximum R/hr reading was 14.
Scans Room 049B floor and walls were scanned for alpha and beta contamination using 434 cm detectors.
2 Comers and cracks were scanned for alpha and beta contamination with 50 cm and 15 cm hand-held 2
2 probes, respectively. Maximum scan results for alpha and beta contamination were below the approve release criteria.
Fixed Measurements Forty-eight (48) two minute fixed beta measurements were obtained on the concrete floor and lower West wall using a 100 cm detector. The maximum result was 595 dpm/100 cm,
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Removable Contamination Survev Fifty-four (54) removable contamination survey wipes were collected on the floor, lower West wall, and on overhead fixtures ofRoom 049B. The wipe sample locations are shown in Attachment 15. The results are provided in Attachment 12. The maximum alpha wipe result for all locations was 55 2
dpm/100 cm and the maximum beta result was 33 dpm/100 cm, well below the approved release 2
criteria for removable contamination.
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Rail & Paint Ramnlen Eight (8) soil samples were taken from cores drilled in the floor of Room 049B and paint samples (2) were obtained from the East and West walls. Results are listed in Attachment 16. The maximu sample result was 0.26 fraction ofrelease limit. The maximum paint sample result was 210 dpm/100 2
2 cm forbeta and 19 dpm/100 cm for alpha contamination.
GA Internal Canfirmatarv Survey GA Confinnatory Surveys were performed according to an approved survey plan (Appendix C) by a Health Physics Technician (Richard Stowell) not assigned to the Stage 3 Final Survey efforts.
Surveys included scans with 434 cm detector, one minute fixed measurements with 100 cm detector, 2
2 and exposure rate readings with pR rate meter. All floor and wall scan results were below approved alert levels. A detailed frisk ofcracks on the floor (with 15 cm GM probe) revealed a small 2
contaminated area (~10 cm ) that was decontaminated. Pre-decon survey result was 400 cpm and post-2 decon result was 180 cpm with 15 cm GM probe. After decon of the small area, no additional 2
contamination was detected in the room. The results of this survey concur with measurements obtained during the Final Survey.
COMPLIANCE WITH THE TARGET CRITERIA GA has decontaminated the Stage 3 area consistent with the State ofCalifornia's and U. S. Nuclear Regulatory Commission's guidelines for Release ofFacilities and Equipment to Unrestricted Use and with approved criteria for residual soil contamination. The results of the final radiation and contamination surveys and soil sampling and analyses are included in this report to demonstrate compliance with the following guidelines.
Facilitier nnd Enninment Concrete and plaster walls of Stage 3 (Room 049B) were cleaned to levels below release limits in Tables 1 & 2 (Attachment 6 & 7). The Final Survey provided in this report demonstrates compliance with these guidelines. See Attachments 12,13,14,15, and 16.
Direct Radiatinn
' The direct radiation levels in all of Stage 3 areas are at or near normal background levels.
All exposure rate readings were <10 pR above background. All direct readings with 100 cm2 beta proportional detector were <600 dpm/100 cm2 (see Attachment 14). Only very low (i.e. < 40 cpm) levels of alpha contamination were detected using a 50 cm' hand-held probe.
Soil Ramnles & Paint Ramnlem The results of analyses of all soil and paint samples were below approved release criteria. See 6, Table 6.
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" Stage 3" (room 049B) of the formerTRIGA Fuel Fabrication " Hot Suite" area, formerly located in northwest corner of the Experimental Building 9, has been decontaminated and radiological s results demonstrate conclusively that contamination and direct radiation exposure levels are below the approved criteria of the NRC and the State ofCalifornia for release to unrestricted use.
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RFFERENCFR 1.
Asmussen, Keith E., letter # CAL-1095 to Mr. Ben Kapel, " Final Survey Report on the Decontamination of GA Technologies' Experimental Building", dated July 28,1987.
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Kapel, Ben R., letter to Keith E. Asmussen dated May 14,1987.
amendment #86 to GA's radioactive material license number 0145-80. Docket #033087-0145 3.
Montgomery, James L., letter dated October 1,1987 to R. N. Rademacher, " Inspection at GA
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Technologies, Inc. (Confirmatory Survey), with Report No. 70-734/87-11.
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License Amendment Number 17 to General Atomics'special nuclear material license number SNM-696, dated December 11,1990.
5.
License Amendment Numbers 97 and 98 to General Atomics' broad scope radioactive material
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license number 0145-80 (now 0145-37) issued by the State of Califomia, dated November 7,1989 January 1,1990, respectively.
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i ATTACHMENT 1: PLAN VIEW OF GENERAL ATOMICS SITE i
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ATTACHMENT 2: FIRST FLOOR IAYOUT OF EXPERIMENTAL BUILDING 9 SHOWING THE PREVIOUS LOCATION OF THE " HOT SUITE" AREA qe N-FORHER TRICA SoIs0!"h)*REA?V['"
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ATTACHMENT 5: DECONTAMINATION STAGES FOR THE " HOT SUITE" AREA
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ATTACf! MENT 6: TABLE 1. USNRC's ACCEPTABLE SURFACE CONTAMINATION LEVELS' Nuclides*
AverageW (dpm""')
Maximurg (dpr#"
Removabg7(dpm"
U-nat,8"U, "U, & associated decay products 5,000 a 15,000 a 1,000 a Transuranics, 88'Ra, "Ra, 8"fh, "Th, "'Pa, 8"Ac, 100 300 20
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'lh-nat, "'Th, "Sr, 8"Ra, 8'*Ra, "'U, "'I, '"I, *I 1,000 3,000 200 Beta / gamma emitters (nuclides with decay modes 5,000 15,000 1,000 other than alpha emission or spontar.cous fission) except "Sr and other noted above.
a Where surface contamination by both alpha-and beta / gamma-emitting nuclides exists, the limits established for alpha and betvgamma-emining nuclides should apply independently.
b As used in this table dpm (disintegrations per minute) means the rate of emission by radioactive matenal as determined by carrectmg the counts per minute observed by an appropriate detector for background, emciency, an geometric factors associated with the instrumentation.
c Measurements of average contaminant should not be averaged over more than I square meter. For objects ofless surface area, the average should be derived for each such object.
d The maximum contamination level applies to an area of not more than 100 cm.
8 e The amount of removable radioactive rnatzrial per 100 cm of surface area should be detemnined by wiping that area with dry filter or 8
soft absorbent paper, applying moders.te pressure, and assessing the amount of radioactive matesial on the wipe with an appropriate instrument of known emeiency. When removable contamination on objects ofless surface area is determined, then pertinent levels should be reduced proportionally and the entire surface should be wiped.
f The average and maximum radiation levels associated with surface contamination resulting from beta-gamma emitters should not exceed 0.2 mrad /hr at I cm and 1.0 rnrad'hr et I cm, respectively, measured through not more than 7 milligrams per square centimeter of total absorber 8
Guidelines For Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses For byproduct, Source, or Special Nuclear Material, USNRC, July 1982, incorporated into GA's SNM 696 license.
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I ATTACHMENT 7: TABLE 2. STATE OF CA ACCEPTABLE SURFACE CONTAMINATICN LEVELS' Nudides' Average **8 (dpm""d)
Maximum *'#
Removable *'8 (dpm"""8)
(dpm"""U U-nat, 8'60, ra*U. 8 associated decay products 5,000 15,000 1,000 Transuranics, 8"Ra, 8Ra, 8Th, azeTh. 8Pa, 100 300 20 827Ac,*l,*l Th-nat, 8Th, "Sr, 82'Ra, 88*Ra, 8" U. '8't, '8't, *l 1,000 3,000 200 Beta / gamma emitters (nudides with decay modes other than alpha emission or spontaneous fission) 5,000 15,000 1,000 except"Sr and other noted above a
Where surface contamination by both alpha and beta /ga.rma-emitting nudides exists, the limits established for alpha-and beta / gamma-omitting nudides should apply independently.
b As used in this table dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, an geometric factors associated with the instrumentation.
c Measurements of average contaminant should not be averaged over more than 1 square meter. For objects of less surface area, the average shculd be derived for each such object.
d The maximum contamination level applies to an area of not more than 100 cm.8 The amount of removable radioactive material per 100 cm of surface area should be determined by wiping that area 8
e with dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the wipe with an appropriate instrument of known efficiency. When removable contamination on objects of less surface area is determined, then pertinent levels should be reduced proportionally and the entire surface should be wiped.
f The average and maximum radiation levels associated with surface contamination resulting from betagamma emitters should not exceed 0.2 mrad /hr at 1 cm and 1.0 mrad /hr at 1 cm respectively, measured through not more than 7 milligrams per square centimeter of total absorber.
Guidelines For Decontamination of Fadlities and Equipment Prior to Release for Unrestricted Use or Termination of Ucenses For byproduct. Source, or Special Nudear Material, USNRC, July 1982, incorporated into GA's SNM 696 license.
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ATTACHMENT 8: TABLE 3. LIST OF IN5MUMENTS
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RATEMETER DETECTOR RANGE CALIBRATION EFFICIENCY BACKGROUND DESCRIPTION (CPM)
DUE DATE (enm)
Ludium Ludlum Model 43-37 9/09/98 a=21.15%
Varies acmrding to Active Probe Area = 434 cm. The detector and ratemeter are 8
Model 2221 gas w ^nii.1 surface being combined and mounted on a roll around cart. The instrument r
S/N 84734 (434 cm ')
Th-230 scanned.
features a static-flow system, quick connects, a portable gas Alpha detector See T %e 4 bottle and a means to adjust the height of the detector from the i
S/N 086236 floor for optimum performanm.
Ludlum L:4,m Modd 43-37 Four Unear 12/30/98 p= 24.12%
Varies ac,vding to Active Probe Area = 434 cm '. The detector and ratemeter are Model 2221 gaspi w e.ai Ranges Sr-90 surfaca beh g combined and mounted on a con around cart. The instrument S/N 73701 (434 cm ')
0 - 500.000 &
scanned.
features a static-flow system. quick connects, a portable gas Beta detector One Log 50 -
See Table 4 bottle and a means to adjust the height of the detector from the S/N 093600 500,000 Moor forw"e am A u.nce.
Ludlum Ludlum Model 43-68 Four linear 11/03/98 p = 27.06%
Varies accordmg to 100 cm' gas flow proportonal counter.
Model 2221 100 cm' ranges surface being S/N 148436 re &nial 0 -500,000 & one Sr-90 scanned.
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beta / gamma log 50-500,000 See Table 4 munter S!N 120477 Ludium Ludium i< del 4345 Four Ranges "0/14/98 21.50 %
Active Probe Area = 50 cm8 Model 12 Alpha Scintinator 0 - 500,000 0
S/N 73924 ZnS(Ag) S/N Th-230 092192 Ludlum Ludlum Model 44-9 Four Ranges 10/05/98 22.84 %
0-120 Acuve Probe Area = 15 cm' Model 3 beta / gamma probe 0 - 500.000 S/N 139168 S/N 145981 Ludium RCA 6199 mupled Five Ranges 8/05/98 N/A 10-18 pR/hr 1 inch x 1 inch Nel (TI) scintillator is mounted intemaRy Model 19 to a Nat (TI) 0 - 5 mR/h pR Meter Scintinator S/N 123930 Exposure < ate meter Canberra Gas Flow N/A Count smears for 26-30 %
a < 0.5 Low Level al p gasrw^arial counting system Low Level Proportonal removable p<2.0 af D Counter alpha & beta alp surface j
Model 2404 detector contamination l
Ludtum RCA 6199 coupled Five Ranges 3/03/98 N/A 10-18 pR/hr 1 inch x 1 inch Nal (TI) scintiHator is mounted intemany Model 19 to a Nat (TI) 0 - 5 mR/h pR Meter Scintillator S/N 144022 Exposure < ate motor 17
[
ATTACHMENT 9: TABLE 4. BACKEROUND MEASUREMNTS AND MDA's 100 cm' Beta Detector Fixed Background Results (S/N 148436)
Background Material Average of10 measurements MDA Building 13 (2 minute counting time)
(dpm/100 cm')
Total counts i2 SD Drywall / Plaster 510 t 15 199 Concrete 933 i19 268 2
434 cm Beta Floor Monitor Background Scan Results (S/N 73701)
{
Background Material Beta / gamma scan range (counts per minute)
Building 13 Drywall / Plaster / Sheetrock 906-1050 Concrete 1795-2030 2
434 cm Alpha Floor Monitor Background Scan Results (S/N 84734)
Background Material Alpha r,can range (counts per minuta)
Building 13
[
Drywall / Plaster / Sheetrock 0-17 Concrete 0-20
(
{
l
{
{
[
l
[
18
c --
1 0: Initi:1 Scan Survey of Stag 3 3 Room 049:
N W
E A
B C
D E
k 60 cpm to 190 cpm a wet scan with 434cm' 1
J 1
275cpra to 440com p Wa#
well scan with 100cmr
\\g F%\\
As m nn, was k
--f s
w,u 4
/j 4 6 cpm to 26 cpm a oc on tile k
to 1150 cpm p. scan on tile
[q 4
'A EA 5
M 6
/
p LU 60 cpm h 190 cpm a waN scan wNh 434cm' 275cprq to 440 cpm $
' Way war scan with 100cma I
6. One minee a cours weh an 434cm' doescsor O. n e naae n d min an 200cm' k I
i
@. conc,. e w.n w w e
@. co,-.e = won u -.
Notes: Initial Scan Survey after false Floor was rernoved.
1.
-100% Ble floor and lower west waB (2 rneters up) was scanned for a and $ with 434cm2 probe.
~25% of lower (lower 2m) North, East and South walls were scanned for a and p with 434cm probe.
r 2.
The values provided are the approximate location of measurements taken. Five minute fixed p reactngs were taken r
- every 2 meters using a 100cm detector on exposed concrete. Tte maximum result was 3198 dpm/100cm.8 3.
20 exposure rate measurements were taken. Exposure rate measurements ranged from 10pR/hr to 12pR/hr.
4.
Only the West war was scanned per the Survey Plan.
19
_ _ _ _ _ 1: Ch:r:ct:rization Sc n Sury;y of Concr:ta Floor N
hE W
A B
C D
E k
l 1
Wall J
1" 2
1 1_.
"W*
1 3
concrek Fka
- ~
y Wall 4
f 5
homsmum amed p --
2119 dprvt
.p f
6
' 'maac I
}__
5
_+
f 7
Wall M.s amm Notes. Characterizaton Scan survey after blastrak.
1.
-100% a & S floor scan w:th 434sn probe after aggressive decontamination of concrete, a results ranged from 1 cpm to 17 cpm and p results ranged from 1300 cpm to 2120 cpm.
2.
Two minute fixed p readings were taken
- every 2 meters (total of 30 readings) using a 100cm detector. The maximum result was 2119 dpm/100cm8 r
3.
Surteos is bare concrete and massc.
l 20 l
ATTACHMENT 12: TABLE 5. STAGE 3 FINAL SURVEY RESULTS 2 Minute Fixed Beta Measurements with 100 cm' Detector Removable Attach #
Location Scan Expos e Contaminaten Smey rate results Results 2
range (434 cm
{~
,)
"W No of 2 min Range of
Background
Max. fixed MDA
- of Maximum Results fixed activity Readmgs reading dpmf Wipes dpm/100 cm2 readmgs 2 nin. Count 2 min. Count dpm'Ise cia 100cm' Alpha Beta 13 NAS Walls 710-940 cpm p (sheet rock) 1-24 cpm a 13 East Wall 820-1700 cpm p (plaster) 2-120 cpm a 13,14,15
- west wall 860-1600 epm p 3
509-650 510
- 15 258 199 3
<10
<10 (plaster) 4-126 cpm a 13,14,15 Concrete Floor 1550-2200 cpm p 11-14 40 870-1259 933*19 595 268 11
<10
<10 2-60 cpm a 13,14,15
- Cracks &
60-180 cpm p 12-14 5
973-1227 933*19 587 268 10
<10
<10 seams wn5cm' (concrete)
GM probe 15 Ceilinsloverhen 30 SS 33 d fixtures 13 Outside concrete 1300-2100 cpm p pad 2-38 cpm a 14 General Area 11-14 l
2
- 50 cm a scan results < 40 cpm.
l l
21
.. 3: Final Beta cnd Alpha Scin Survey Soil cnd Paint Simpl:s of St:gs 3 l
N o
WkhE A
B C
D E
k
---4 1
Wall
)I 2
- e. _
2 to 60 a scan 1550 to 2200 $ scan 3
Wall-
'~
Wall 2 to 38 a scan h
4 1300 to 2100 p a::an L
Paint Sample B s
o e 2 to w a -an e
Paint Sample A 1550 to 2200 p scan 7
Wall
_L
. ~ o,.n
.. cow s s.mpi.
Q = Paint Sample Ngteg; Beta and Alpha scans on floor and West wall and locations of paint and soil samples.
1.
-25% of lower North and South walls were scanrugs for a A p with 434cm2 detector, a scan results rangsd from 1 cpm to 24 cpm.
p scan resuns ranged from 720 to 940 cpm. -10% of North & South upper walls were scanned for a & p.
p scan results ranged from 710 to 920 cpm, a scan results ranged from 1 to 18 cpm.
M dry war surfaces on North and South walls.
- 2. -100% of lower East and West walls were scanned for u & p with 434cm2 detector. a scan results ranged from 2 cpm to 126 cpm.
p scan resuns ranged from 820 to 1700 cpm. -10% of West & East upper walls were scanned for a & S. p results ranged from 860 to 1340 cpm.
a results ranged from 2 to 74 cpm. AN plastertement block surfaces on East and West walls.
- 3. -100% of concrete floor and outside concrete pad was scanned for a & S with a 434cm2 detector.
4.
Paint and soil samples were collected. AH results are provided in attachment 16.
- 5. All cracks and seams were scanned with harxl held 15cm'lVy GM and 50cm a detectors. Results were lVy < 180 cpm and a < 40 cpm.
2 22 e
[; 4: Finil Surv:y of St ge 3:2 Minuta Fixed Bitund Exposurs Rita M:csurernents N
W hE A
B C
D E
k 1
Wall I
< 2ee
< ese
< ese
<aos <ase ase
< aos
< res sm
< 2ee 9"*~<2e8"
- "" *' W-M '
- ' +
< tes 3
2
? es_.. - 4 s 2ee_
? eq.
2 n,
' 2ee " " aso
'[2ee W8ll
,e, 4
rear
- mr
<m
<m
< 288 1
< 2es Q."; ;
I f
= 2e8 s
<m
< 2ee m.4 2
_., Pee ~
, pas 6
< res i
< res 7
Wall l
<w Notes:
Two minute fixed Beta measurements converted to dpm/100cm and Exposure Rate Measurements in pR/hr r
- 1. The values marked ort the floor sire the approximate locations of measurements taken. Two minute fixed p readings were taken on concrete floor - every 1 meter (total of 45 readings) using a 100 cm2 detector. The maximum results was 602 dpm/100cm'.
Numbers in bold type are greater than the MDA for concrete the MDA is LWkipm/100cm,r
- 2. The values marked on the West wall are the approximate locations of measurements taken. Two minute fixed p readings were taken
- every 3 meter on West wall (total of 3 readings) using a 100 cm2 detector. The maximum results was 259 dpm/100ctn' (MDA for plaster wall is 199dptrv100cm')
- 3. 58 exposure rate measurement (s) were taken. Maximum result on surface was 14pR/hr & Maximum result O 1eneterabove surface was 14pR/hr.
23
Attachm:nt 15: Final Removable Contamination Survey of Stage 3 l
N wd3*E A
B C
D E
k 1
Wall l-9 e
e e;
e t
-l l
@O l
2 e e
e p
_ $_ _.___ _ _ _ _. _.,., o i
Z= ~t*
l e
t i
3 l 0
l o
i l
9
. 9.. o _
Og l
g_
above 2m
~
" * ~
gg Wall above 2m I
O l
, %--r e
l 4
o*
l o,
.]_,.
,i n.
l 0
5 l
l l
3_.
e _ _ :_.l -l l
4 g
l 7
Wall I
I I
N **
@ = OverHeadStruaures Notes: Locations of Removable Contamination surveys
- 1. The numbers circled are approximate locations of wipes tak61 on walls and floor.
Wipe results, all were <10 dpm/100cm' & a all were <10 d vn/100cm'.
i 2.
The shaded nurnbers circled are approximate locations of wipes bken on ceiling and overhead fixtures.
Maximurn wipe results, p was 33 dpm/100cm' & a was 55 dpm/100cm'.
3.
All me'al. plaster / cement block & concrete surfaces.
24
.,.5 ATTACHMENT 16: TABLE 6. Soil and Paint Samples from Room 049B*
Paint Samples (See Attachment 13forlocations)
(See attachment 11forlocations)
'U-234 Total enriched Sampic #
(pCi/g)
(pCi/g) eraalum
' Fraction of Alpha Beta Background included Background included (pCilg) release limit (dpm/100 cm')
(dpm/100 cm')
1 0.34
- 0.11 7.48 7.82 0.26 2
0.10
- 0.05 2.20 230 0.08 3
021* 0.08 4.62 4.83 0.16 4
0.24
- 0.07 5.28 5.52 0.18 5
0.22
- 0.12 4.84 5.06 0.17 6
0.21
- 0.08 4.62 4.83 0.16 7
0.26
- 0.09 5.72 5.98 0.20 8
0.19
- 0.12 4.18 4.37 0.15
^
19 210 B
5 62
- Gamma spatroscopy showed only natural background levels of thorium, radium-226, and cesium-137.
- 1. Based on uramum isotopic analysis ratio of 22:1 (U-234 : U-235). See arrachment 17for calculations.
- 2. Enriched uranium release limit is 30 pCi/g.
25
~
J
=
l l
ATTACHMENT 17: Uranium isotopic Analysis Results from Room 049 (Stage 3).
l U-235 : U-235 Ratio (sample A) = 241/11.1 = 21.7
- U-234 : U-235 Ratio (sample B) = 16/0.805 = 19.9 i
Uranium Enrichment calculatinn (namnle Ah (241 pCi U-234/g sample) (g U-234/6245.75e' pCi U-234) = 3.86e-8 g U-234/g sample (11.1 pCi U-235/g sample) (g U-235/2.116e' pCi U-235) = 5.14e g U-235/g sample 4
(48.3 pCi U-238/g sample) (g U-238/0.336e' pCi U-238)_ = 1.44e g U-238/g sample 4
1.49e"g U/g sample 4
% U-235 = r U-235/ total U = 5.14e /1.49e"= 0.0345 = 3.5% enrichment Uranium Enrichment Calculation (umnles Bh (16.0 pCi U-234/g sample) (g U-234/6245.75e' pCi U-234) = 2.56e g U-234/g sample 4
(0.805 pCi U-235/g sample) (g U-235/2.le' pCi U-235)
= 3.73e g U-235/g sample d
(3.35 pCi U-238/g sample) ( U-238/0.336e' pCi U-238)
= 9.97e~'g U-238/g sample 4
1.03e g U/g sample 4
4
% U-235 = g U-235/ total U = 3.73e /1.03e = 0.0287 = 2.9% enrichment j
Enrichment is ~ 3-3.5%, therefore alpha / beta ratio is ~ 3:1 Approximate release limit for beta is:
l 5000 dpm"*"* alpha
= 1667 dpm"*"* beta l
4 4
t l
l 26 i
APPENDIX A i
l l
f
February 20,1998 Laura Gonzales I
d*
Characterivatian Survey Pl== of R-::r 049 - BuiWi== 9
-l
Background
Room 049 of Buiding 9 used to be part of the TRIGA Fuel Fabrication Facility prior to 1975.
Enriched uranium was used in this area for these operations. Recently, the room was used as the telecommunications site for GA. The original concrete floor was covered with tile and a raised wooden floor was installed over it enclosing cables undemeath.
As of February 20,1998, the cables and " false" floor have been removed, but most of the tile is still there. The tile may be an asbestos tile. According to Chad Taylor, it will either be sampled or treated as asbestos tile. A survey of the cables and the tile undemeath was done in accessible areas prior to this survey.
The purpose of this survey is to determine if aggressive decontamination, i.e., blastrac of the concrete floor will be needed. If the tile contains asbestos, then an asbestos contractor will have to do the decontamination. If the tile does not contain asbestos, then GA will do the decontamination, if required.
' f.
Scan 100% surface of tile (alpha and beta) with 434 cm2 probe.
4.
Scan surfaces whem tile is not present using the 434 cm2 probe (alpha and beta).
i Document all readings.
3' Take 5 minute readings on exposed concrete (beta only using 100 cm2 probe).
4.
Take microR readings on surface and 1 m throughout the room.
t Take hand held alpha and beta / gamma measurements on exposed concrete surfaces.
Yr-Survey any cracks in the floor which may be visible.
j Scan (alpha and beta) along the west wall for contamination -- ~25% of the bottom 2 m and ~100% of the bottom 2'.
Documentation I
Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument (s) used (including model and serial number of both the ratemeter and the detector),
calibration due date, % efficiency, background readings (if applicable) and any other applicable infonnation.
I l
W:\\D-PLAN \\049.PS l
i May 27,1998 Laura Gonzale characterization Survey Plan of Concrete Floor in Room 049 - Buildine 9
Background
Room 049 of Buiding 9 used to be part of the TRIGA Fuel Fabrication Facility prior to 1975.
Enriched uranium was used in this area for thpse operations. Recently, the room was used as the telecommunications site for GA. The original concrete floor was covered with tile and a raised I
wooden floor was installed over it enclosing cables underneath. A survey of the cables and the tile undemeath was done in accessible areas prior to this survey and documented. No contamination was detected.
I As of May 27,1998, the cables and " false" floor have been removed and on Saturday, May 16, 1998, the tile and the mastic were removed and disposed of as mixed waste (the mastic had tested l
positive for asbestos). The tile and mastic waste was placed in an LSA box and transferred to the NWPF facility on May 27,1998.
The purpose of this survey is to scan 100% of the concrete floor for both alpha and beta contamination. Results of this survey may be used for tly, Final Survey depending on what is found. This scan will determine if aggressive decontamira tion, i.e., blastrac is needed.
1.
Scan 100% surface of concrete (alpha and beta) v ith 434 cm2 probe.' Document all I
readings.
2.
Take microR readings on surface and I m from the surface (report if> 20 R/hr).
3.
Take hand held alpha measurements (50 cm2 probe) to see if there is contamination above the limits. Ifyes, mark the area. Ifno contamination is found, use the 100 cm2 probe to check the elevated area. Take 2 minute readings.
4.
Survey all cracks in the floor which may be visible with a GM counter and alpha counter.
Alert Levels
> 200 cpm alpha using the large area (434 cm ) probe.
2 l
> 150 cpm using a hand-held alpha probe (~1500 dpm/100 cm )
2 Bets Alert Levels 2
> 100 cpm with 100 cm probe.
Documentation I
Every survey con:!ucted must be documented on a daily basis on a drawing showing the approximate locations surveyed. Irichide the results (including units), the technicians signature, date, l
instrument (s) ure:' r. including model and serial number of both the ratemeter and the detector),
I calibration due date, % efficiency, background read'ngs (if applicable) and any other applicable information.
W:\\D-PLAN \\049.598 r
e
l
{
APPENDIX B
[
f I
r L
i
[
p manamurm myanscar
[
INTERNAL CORRESPONDj&
NCE Laura Gonzalch r
From:
In Reply L
Refer To:
LQG:98:105 To:
Distribution Date:
June 15,1998
{
Subject:
Final Survey Plan for Room 049 of Building 9 (Former TRIGA Fuel Fabrication
{
" Hot Suite" Area," Stage 3")
(
A Radiation Work Permit has been approved for the removal of the remaining mastic on the concrete floor of Room 049 of Building 9 (the former TRIGA Fuel Fabrication " Hot Suite" Area, also known as " Stage 3") which will be beginning at about 3:30pm today. The work will be
[
done using GA's blastrac unit which will remove the mastic and about 1/4" of concrete (or deeper along cracks). Jerry Cooper (who took a class on using the unit) will train the contractors in the use of the unit and will be available should it fail or need repair during thejob.
Hopefully, removal of the surface concrete will remediate all but the concrete edges which the f
blastrac unit cannot reach. The edges will be decontaminated (as needed) by Jerry Cooper using t
the needle gun beginning tomorrow afternoon 3:30pm.
[
The Final Survey Plan has been completed (see attachment) and will be implemented starting L
June 16,1998. The plan includes the removal of the covering over the floor drain line so Health Physics can monitor it and also includes core soil sampling undemeath the concrete. These items
{
are being coordinated with F. Dahms.
Distribution: K. Asmussen F. Dahms U. Wells E. Ramirez C. Taylor P. Maschka D. Keesling J. Turner B. LaBonte R. Dalry (w/o attachment)
R. Noren (w/o attachment) i
1 June 15,1998 Page 1 of 5 June 15,1998 Laura Gonzales dh b 6/ISY 8 Final Radiological Survey PInn for Room 049 of Buil<line 9 "Staec 3" (formerTRIGA Fuel Fabrication Room)
This Final Radiological Survey Plan covers Room 049 of Building 9 " Stage 3" of the former TRIGA Fuel Fabrication Facility (also called the " Hot Suite").
Figure I shows the location of the forrner " Hot Suite" area in relationship to the rest of the building.
i Figure 2 shows the current configuration of the Former " Hot Suite" area. Figure 3 shows the former " Hot l
Suite" area of Building 9 and Figure 4 shows the locations of" Stage 1"," Stage 2" and Stage 3" rooms.
Stage 1 and 2 rooms have already been released to unrestricted use.
Background
l This room was initially part of the " Hot Suite" area of TRIGA Fuel Fabrication until about 1975 when i
operations were moved to Building 22. The area was decontaminated at this time but not released to unrestricted use. The room was used until recently (12/97) to house GA's communication systems. A i
rnised wooden, tiled floor was installed to enclose the cables. The communication equipment was installed on top of the raised flooring. The room measures -19.7' X 27'(~531 ft2).
The cables underneath the false floor were surveyed and found to be clean. The telecommunication equipment was moved to a nearby room. The tile was surveyed and found to be radiologically clean, however, the mastic underneath the tile was found to contain asbestos. An asbestos abatement company was hired to remove the tile and mastic. A Radiation Work Permit was issued to perform this work on May 26,1998. A Characterization Survey Plan was issued on May 27,1998 for surveying the concrete but could not be implemented because a large area of the floor still had mastic covering the concrete; preliminary surveys on concrete surfaces, which have no tile, show some alpha contamination.
The mastic contains some asbestos and must be removed and prevents good alpha surveys from being performed. To remove the mastic, GA plans to hire an asbestos abatement contractor to use GA's blastrac unit to remove the mastic on June 15,1998. Since some alpha contamination is known to be present, the blastrac unit will also be used to remove a small layer of concrete as well in order to decontaminate the surface (this was discussed with Chad Taylor from facilities).
Historical data shows that depleted uranium and uranium of various enrichments were used in this room.
Characterization data to date shows some alpha contamination present in areas which could be surveyed (missing tile on the concrete surface). In addition 2 concrete samples collected and analyzed by gamma l
spec showed positive U-235 contamination. These concrete samples were sent offsite for uranium isotopic analyses to determine the U-234:U-235 ratio, the alpha: beta ratio and the U-235 % enrichment of the uranium. The results (see LQG:98:70) gave a ratio of 22:1. The enrichment was calculated to be only l
cbout 3.5%. For this enrichment, the alpha: beta ratio is approximately 3:1.
WAD-PLANO 49-FsP.98 l
I l
June 15,1998 Page 2 of 5 Cl==m ation c
The room is categorized as a " suspect affected area" due to contamination being detected and a re past activities.
Survey Obiectives and Dar=nsibility ne purpose of performing a final survey is to demonstrate that the radiological conditions in Room 049 Building 9 satisfy the NRC and State of CA guidelines for release to unrestricted use. The objectives include (1) to show that the average surface contamination levels for each survey unit are within the cuthorized value, (2) to show that the maximum residual activity (" hot spot" area) do not exceed three times the average value in an area up to 100 cm and (3) that a reasonable effort has been made to clea 2
removable contamination and fixed contamination and (4) that the exposure rates in occupiable locations are less than 10 pR/hr above background measured at I meter above the surface. Samples will be counte in the IIcalth Physics laboratory (onsite). Surveys will be taken only by qualified Health Physics Technicians having a minimum of 3 years IIcalth Physics Technician experience in accordance. The survey and final report documenting the survey will be performed by GA's Health Physics group.
Seil Saraling if remediation of the concrete leads to the soil (i.e., thwagh cracks in the concrete), then soil sampl be collected in these locations in addition to the 4 evenly distributed random core samples addressed in pt:n. In addition, soil sampling near the floor drain is required (at least 2 soil samples).
Release Criteria (per GA Site Dc-a,mmi-bnina Plan)
Facility Structure Crittria The applicable guidelines for residual contamination on building surfaces for enriched uranium are:
5,000 dpm a/100 cm, averaged over a 1 m area 2
2 15,000 dpm a/100 cm, total, maximum in a 100 cm area 2
2 1,000 a dpm/100 cm, removable activity 2
in Room 049, the alpha: beta ratio is estimated at 3:1; therefore, beta monitoring will be performed and th cctivity levels are reduced accordingly as follows:
1,667 dpm/100 cm, averaged over a 1 m area 2
2 5,000 dpm/100 cm, total, maximum in a 100 cm area 2
2 333 dpm/100 cm, removable activity 2
Exnosure Rate Measurements The guideline value for exposure rates measured at I m above the surface, is 10 R/hr above backg Soil Criteria Th3 release criteria for soil (values are above background levels)is specified in the Site Decomm W:\\D-PLAN \\O49-FsP.98 t
~-
t i
June 15,1998 Page 3 of 5 Plan as 30 pCi/g for Enriched Uranium (U-234 plus U-235).
The U-235 value is obtained by gamma spec; the U-234 value is calculated using the 22:1 U-235:U-234 ratio (obtained by uranium isotopic analyses done on the concrete samples). Therefore, the U-235 concentration cannot exceed 1.3 pCi/g [1.3 pCi/g + (22)l.3 pCi/g] = ~30 pCi/g.
f Alert Levels If the following " alert levels" are exceeded, notify HP Management so an evaluation can be performed to detennine ifincreased survey coverage or decontamination is required.
Dafsac_rtit.Rrh l Note: Alert levels for other surfaces can ba estimated as the background cpm plus the epm value provided below for each instrument type].
Aloha Alert Values
> 200 cpm alpha using the large area (434 cm ) probe 2
2 2
> 150 cpm using a hand-held 50 cm alpha probe (~ 1500 dpm/100 cm )
Beta Scanning usine the 434 cm' probe
> ~1900 cpm beta using the large area (434 cm ) probe (#84459) 2
> ~2300 cpm beta using the large area (434 cm ) probe (#73701) 2
> ~300 cpm above background of another 434 cm ) probe - make sure the background determination has i
2 been completed at Building 13 (or other HP management approvedlocation)
Beta FixedMeasurements usine the 100 cm nrobe i
2
> ~1300 counts in 2 minutes using the beta 100 cm gas flow proportional counter (s/n 84423) 2
> ~1150 counts in 2 minutes using the beta 100 cm gas flow proportional counter (s/n 86332) l 2
> ~200 cpm or 400 counts in 2 minutes above background for other beta 100 cm gas flow proportional 2
counter or if probe calibration has changed or of other changes to the meter have been made --
make sure the background determination has been completed at Building i3 (or other flP management approvedlocation).
Decontamination Required - When (1) GM measurements > 150 cpm or (2) values greater than 2
those provided above using the 100 cm probe.
On Soil Any radionuclide above natural background levels (see HP-40 for background levels). All soil sample results must be reviewed by Laura Gonzales or Paul Maschka.
Exoosure Rate Measurement - Alert Levels Background exposure rate is normally 15 R/hr above background at I m but varies depending on location and surrounding structures (upper metal mezzanines are a lot lower and concrete vaults are higher). If levels > 20 pR/hr are measured at I m, notify HP Management.
W:\\D-PLAN \\o49-FsP.98
1 i
June 15,1998 Page 4 of 5 i
. Documentation Every survey conducted must be documented on a daily baris on a drawing showing the approximate locations surveyed. Include the results (including units), the technicians signature, date, instrument (s) used (including model and serial number of both the ratemeter and t' e detector), calibration due date, %
c fYiciency, background readings (if applicable) and any other applicable information.
i l
i i
(
W;W-PLAMG49-FSP.98
June 15,1998 Page 5 of 5 Surveys Planned for Room 049 of Building 9 (as of June 15,1998)
Room 049 of Building 9 (~531 ft )
2 Type of Survey
(~50 m )
2 Concrete Floor ")(scan w/434 cm'pmbc) 100 % a 100% p Detail survey along cracks in the concrete floor needed Lower West (Original) Wall Scan (bottom 2m) 100 % a i
8 (Scan w/ 434 cm pmbe) 100% $
Lower North, East and South Wall Scan (bottom 2m) 25% a (scan w/434 cm'probc) 25% p North, South, East and West Walls (above 2 m) 10 % p (Scan w/ 434 cm'pmbc)
Minimum number of Measurementson (4)
Measurement every ~2 m See Figure 5 Altemate between (1) a wipe and (2) a beta fixed measurement on the floor and up the west original wall (on the wall collect a measurement only at I m from surface; every 2 m)
Drain Line (There is one covered drain line in the room)
The drain line has a inetal plate that needs to be removed
)
then we can check the inside of the line Overhead Structures Wipes needed on the large fire sprinkler line and I-beams (take a minimum of 30 wipes evenly spaced) 0 of Soil Samples (core samples) 4 Evenly distributed in room See Figure 6 plus 2 next to the floor drain andin locations where remediation went to soil
- of Paint Samples 2-east wall and west wall See Figure 6 (The other 2 walls are not original walls and the drywall has been removed) pR/hr Readings @ lm from surface (See Figure 7)
I every 3 m Outside of building a and (scan w/ 434 cm'pmbe)
Scan 100% out ~l m from the door
")
Clean all surfaces to remove debris or dirt (wash, mop and/or vacuum, as needed). Grid (2 m grid pattern).
til For removable measurements, take a 100 cm wipe at each location and count using a low 2
level alpha / beta counter.
")
For the fixed measurements:
For p measurements; take a 2 minute count using the 100 cm gas flow 2
proportional detector (beta) with the Model 2221 ratemeter. Document all readings and mark on a drawing the locations the readings were taken.
WAD-PLANiO49-FSP.9B
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APPENDIX C
E l
August 5,1998 Page 1 of 4 M
a Go es
{
GA Intcrnal Confir=== tory Survey Plan for Room 049 of Buildine 9 "Simme 3" (former TRIGA Fuel Fabrientian Room) d
(
This intemal confirmatory survey plan covers Room 049 of Building 9 " Stage 3" of the former TRIGA Fuel Fabrication Facility (also called the " Hot Suite").
[ Refer to Final Radiological Survey Plan for room 049 dated June 15,1998 for more information).
BM-round This room was initially part of the " Hot Suite" area of TRIGA Fuel Fabrication until about 1975 when operations were moved to Building 22. The area was decontaminated at this time but not n: leased to unrestricted use. The room was used until recently (12/97) to house GA's communication systems. A raised wooden, tiled floor was installed to enclose the cables. The communication equipment was installed on top of the raised flooring. The room measures ~19.7' X 27 (~531 ft').
Historical data shows that depleted uranium and uranium of various enrichments were used in this room.
Two (2) concrete samples were collected and analyzed by gamma spec showed positive U-235 contaminada.. These concrete ew;hs were sent offsite for uranium isotopic analyses to determine the U-234:U-235 ratio, d.s alpha: beta ratio and the U-235 % enrichment of the uranium. The results (see LQG:98:70) gave a ratio of 22:1. The enrichment was calculated to be only about 3.5%. For this enrichment, the alpha: beta ratio is approximately 3:1.
l Classification The room is categorized as a " suspect affected area" due to contamination being detected and a review of past activities.
Survey Obiectives and Responsibility The purpose of performing this internal confirmatory survey is to double check that the radiological conditions in Room 049 of Build'ng 9 satisfy the NRC and State of CA guidelines for release to unrestricted use. A Health Physics Technician not involved in the original characterization, decontamination and final survey will perform the survey.
Eclease Criteria (per GA Site Decomrnissioning Plan) j Facility Structure Criteria l
The applicable guidelines for residual contamination on building surfaces for enriched uranium are:
2 2
(
5,000 dpm a/100 cm, averaged over a 1 m area l
15,000 dpm a/100 cm, total, maximum in a 100 cm area 2
2 2
1,000 a dpm/100 cm, removable activity WDPLAN\\O49-CS.98 f
L r
August 5.1998 Page 2 of 4
~
In Room 049, the alpha: beta ratio is estimated at 3:1; therefore, beta monitoring will be performed and the activity levels are reduced accordingly as follows:
2 2
1,667 dpm/100 cm, averaged over a 1 m area 2
2 5,000 dpm/100 cm, total, maximum in a 100 cm area 2
333 dpm/100 cm, removable activity Ernosure Rate Ma=ure===ts The guideline value for exposure rates measured at I m above the surface, is 10 R/hr above background.
Soil Criteria The release criteria for soil (values are above background levels) is specified in the Site Decommissioning Plan as 30 pCi/g for Enriched Uranium (U-234 plus U-235).
The U-235 value is obtained by gamma spec; the U-234 value is calculated using the 22:1 U-235:U-234 ratio (obtained by uranium isotopic analyses done on the concrete samples). Therefore, the U-235 concentration cannot exceed 1.3 pCi/g [1.3 pCi/g + (22)l.3 pCi/g] = ~30 pCi/g.
Alert Levels If the following " alert levels" are exceeded, notify IIP Management so an evaluation can be performed to determine ifincreased survey coverage or decontamination is required.
On Concrete or AsphmIt Surfaces (Note; Alert levels for other surfaces can be estimated as the backgmund cpm plus the cpm value provided below for each instrument type].
Alpha Alert Values
> 200 cpm alpha using the large area (434 cm ) probe 2
> 150 cpm using a hand-held 50 cm alpha probe (~ 1500 dpm/100 cm )
2 2
Beta Scanning using the 434 cm probe 2
> ~1900 com beta using the larne aren (434 cm ) orobe (#84459) 2
> ~2300 cpm beta using the large area (434 cm ) probe (#73701) 2
> ~300 cpm above background of another 434 cm ) probe - make sure the backgrounddetermination has 2
been completed at Building 13 (or other HP management approved location) 7 Beta FixedMeasurements using the 100 cm probe 2
l
> ~800som using the beta 100 cm gas flow proportional counter (s/n 84423) 2 Decontamination Required - (1) When GM measurements > 150 cpm and the area is > 100 cm,
2 I
or (2) GM measurements are > 200 cpm and the area is 5100 cm or (3) values greater than those 2
provided above using the 100 cm probe (> 800 cpm with the s/n 84423 probe).
2 CAD-PUNO49CS.98
p_
(. -
August 5,1998 Page 3 of 4 Reasoning:
11.
200 cpm-100 cpm bkg = 100 cpm net / effx A/100 = 100/-0.22 x 15/100 = 3,030 dpm/100 2
2 2
cm -- Limit is 5,000 dpm/!00 cm, total, in a maximum 100 cm area (using 3:1 alpha / beta q
ratio).
2.
150 cpm-100 cpm bkg = 30 cpm net /effx A/100 = 100/4.22 x 15/100 = 1515 dpm/100 cm 2
{
Limit is 1,667 dpm/100 cm, averaged over a 1 m area (using 3:1 alpha / beta ratio).
2 2
3.
800 cpm - 502 cpm bkg = 298 cpm net /efTx A/100 = 1089 dpm/100 cm -limit is 1,667 2
2 2
{-
dpm/100 cm, averaged over a i m area OnSoil
{
- No soil samples required in this confirmatory survey.
Frnn==e Rate Measurement - Alert Levels
[
Background exposure rate is normally 15 pR/hr at I m but varies depending on location and sunounding i
stnactures (upper metal mezzanines are a lot lower and concrete vaults are higher). If levels > 20 pR/hr are measured at I m, notify HP Management.
f' Documentation Every survey conducted must be documented on a daily basis on a drawing showing the approximate locations surveyed.- Include the results (including units), the technicians signature, date, instrument (s) used
(
(including model and serial number of both the ratemeter and the detector), calibration due date, %
l efficiency, background readings (if applicable) and any other applicable information.
For geiger counter readings, document the size of the area if readings are between 150 cpm and 200 cpm.
L
{
{-
b W:DPLAMO49C.98
August 5,1998 Page 4 of 4 Surveys Planned for Room 049 of Building 9 (as of August 5,1998)
Room 049 of Building 9 (~531 ft )
2 Type of Sun'ey
(~50 m )
2 Concrete Floor m (scan w/434 cm'pmbe) 25 % a #
25% Q V
'SC'~
f Detail survey along cracks in the concrete floor neededI foc.?c4 W
k tower North and West (Original) Wall Scan 100 % a (bottom 8" only) P (bottom 8" not entire 2 m) represents ~10% of the 2m 100 % p (bottom 8" onlyV
[
area (Scan w/ 434 cm'pmbe) k Lower East and South Wall Scan (bottom 8")
25% a (bottom 8" only) '
(Scan w/ 434 cm'pmbe) represents ~2.5% of the 2m 25% p (bottom 8" onlyV North, South, East and West Walls (above 2 m)
None 2
(Scan w/ 434 cm pmbe) y Minimum number of Measurements
- Take 5 p fixed measurements - I min each (Evenly spaced)/
[
Drain Line (There is one covered drain line in the room)
None required Overhead Structure smears None required
- of Soil Samples (core samples)
None See Figure 6
[
- of Paint Samples None N/ pR/hr Readings @ Im from surface (see rigure 7) 5 readings in he room (evenly spaced)V
[
T)utside of building a and D (scan w/434 cm probe)
Spot check for contamination 3' v
2
/
m Clear; all surfaces to remove debris or dirt (wash, mop and/or vacuum, as needed). Grid (2 m grid pattern).
m For the fixed measurements:
For p measurements; take a 1 minute count using the 100 cm gas flow 2
proportional detector (beta) with the Model 2221 ratemeter. Document all readings pud mark on a drawing the locations the readings were taken.
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W:\\D-PLANO 49-CS.98 I
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