ML20149F197
| ML20149F197 | |
| Person / Time | |
|---|---|
| Issue date: | 07/15/1994 |
| From: | Barkley R, Kinneman J, Duane White NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20149F181 | List: |
| References | |
| REF-QA-99990001-940725 99990001-94-11, NUDOCS 9408100028 | |
| Download: ML20149F197 (11) | |
Text
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4 U.S. NUCLEAR REGULATORY COMMISSION REGION I Report No.
99990001/94-01l License No.
29-01248-02 (retired)
Former Licensee:
Western Electric Comoany Inc.
100 Central Avenue Kearney. New Jersey 07032 Facility Name:
AT&T Microelectronics InspecSon At:
Cark Submarine Repeater Plant 100 Terminal Avenue Clark. New Jersey Inspection Conducted:
June 7.1994 7!/ f/<((~
Let f
.' ie 'f Inspectors:
k Duncan White, Health Physic 6t date
?x ad 7/11J1+
w kichard S. Barkley, Senior Kealth Physicist date Approved by:
)
7!/fV X)hrh D. lTnnerfan, Chief
'datd
)ecommissioning Section Insocction Summary: Closcout inspection on June 7,1994 (Inspection No. 99990001/94-011).
Arcas Inspected: Announced, closcout inspection limited to a confirmatory survey of AT&T Microelectronics' Clark, New Jersey facility for residual cesium 137 (Cs-137) contamination prior to release of Rooms 1 though 5 (former radioisotope inspection facility) and 160 feet of trench adjacent to these rooms for unrestricted use. Eight wipes and nine soil samples were taken and assayed for residual Cs-137 contamination. The rooms and trench were surveyed to identify remaining Cs-137 contamination.
9400100028 940725 REG 1 GA999 ENV*****
99990001 PDR
2 Results: One sample of residual material from inside the drain pipe leading from Room 5 to the north hallway trench and drain line removed from the trench had contamination levels in excess of NRC guidelines for residual Cs-137 contamination in soil. The remaining eight soil samples taken along the 160 feet of trench adjacent to the former radioisotope inspection facility had concentrations less than the NRC guidelines for residual Cs-137 contamination in soil. All areas surveyed for surface and removable surface contamination meet NRC guidelines for release for unrestricted use.
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DETAILS 1.
Persons Contacted
- Michelle Blazek, Environmental Health and Safety Engineer, AT&T Bill Csaszar, Radiation Physicist, New Jersey Department of Environmental Protection j
and Energy l
Linda Floyd, Environmental Health and Safety Engineer, Submarine Lightwave Repeaters, AT&T Microelectronics
- James Hancock, Radiation Safety Officer and Project Manager, US Ecology
- Richard Kumor, Environmental Health and Safety Engineer, Submarine Lightwave Repeaters, AT&T Microelectronics John Riley, Radiation Safety Officer, AT&T Bell Laboratories Various US Ecology field personnel Denotes those present at exit interview.
===2.
Background===
Western Electric Company was authorized to possess and use 800 millicuries of Cs-137 in any chemical or physical form to leak test brazed tubulation closures used in submarine cable repeaters. The license expired on March 31, 1978. The licensee l
terminated licensed activities in 1978 and conducted a closcout survey of the radioisotope inspection facility (now referred to the x-ray laboratory or Rooms 1 through 5) on November 6, 1978.
NRC Region I conducted a confirmatory survey of the decontar en of the Clark facility on November 6,1978 and concluded in a letter dated N ntier 17,1978 that the facility met NRC guidelines for release for unrestricted release. The NRC retired License No. 29-01248-02 on January 8,1979.
A survey in July 1992 by AT&T identified residual Cs-137 contamination in a drain line exiting the test laboratory and in a section of the exhaust duct in the former radioisotope inspection facility. AT&T subsequently took the initiative to remediate the Cs-137 contamination and contracted with US Ecology to perform the remediation work. A decommissioning plan for portions of the Clark facility contaminated with Cs-137 from licensed activities conducted under License No. 29-01248-02 was prepared by US Ecology and submitted to the NRC by AT&T on October 18, 1993. Region I staff reviewed the plan and requested additional information in a letter dated November 22, 1993. AT&T provided a response to the NRC in a letter dated January 17,1994. In a letter dated February 28, 1994, Region I indicated that they had no objection to irrplementation of the decommissioning plan. On April 26, 1994, an NRC inspection was conducted at the Clark facility to observe remediation activities and to review the final survey methods. The results of that inspection are documented in Inspection Report No. 99990001/94-06.
4 On May 3,1994, AT&T and US Ecology contacted the New Jersey Spill Reporting Hotline in response to the recognition of a potential for the prior release of radioactive and possibly hazardous materials through the corroded portion of the drain line. A followt p 30 day report to the State of New Jersey was submitted on June 1,1994.
AT&T 3rovided these reports to the inspectors during the inspection.
No s'.fety concerns were identified.
3.
Instruments Used in the Survey Gamma radiation measurements were taken with a Ludlum Model 19 micro-R meter (NRC serial No. 019635) last calibrated on January 14,1994 to Cs-137. The ambient background gamma radiation level measured in the vicinity of the facility was approximately 10 microroentgens per hour ( R/hr). Inside the excavated trench, the ambient background was higher and measured approximately 20 pPJhr. The higher background in the trench was determined to be the result of the close proximity from three surfaces of soil in close proximity to the detector compared to the one surface normally encountered inside room or outdoor areas.
Fixed surface contamination was measured with an Eberline Model ESP-2 (NRC Serial No. 021941) with a Eberline Model HP-260 Geiger-Mueller pancake detector (NRC Serial No. 021943) calibrated on November 12,1993. The detector had an effective area 2
of 15 square centimeters (cm ). Additional calibration of this detector was performed on June 6,1994 with a chlorine 36 (Cl-36) source traceable to the National Institute of Science and Technology (NIST). Cl-36 was utilized to calibrate the detector because the average energy of the beta radiation emitted by Cl-36 is similar to Cs-137. Cs-137 could not be used to calibrate for surface contamination because of interference from the gamma radiation emissions from barium 137m (Ba-137m).
The detector had an ef6ciency of 20% for Cl-36; however, a conservative ef6ciency of 15% was assumed for Cs-137. The minimum detectable activity (MDA) for Cs-137 for this detector is approximately 3,600 disintegration per minute per 100 cm (dpm/100 cm ).
2 2
Wipes were counted for 10 minutes on a Tennelec Model LB5100 Series II low background alpha / beta counter at the Region I of6ces for Cs-137 activity. The ef6ciency for Cs-137 was 26.7% with an MDA of 5.8 dpm per wipe. Results were reported in dpm per wipe at an uncertainty of one sigma.
Soil samples were counted for 3,000 seconds in 250 milliliter (ml) Marinelli beakers on a Princeton Gamma-Tech high purity germanium detector coupled to a Nuclear Data Accu-Spec multichannel analyzer at the Region I of6ces. The relative efficiency of this detector was 28%. The Cs-137 concentration reported is based on the concentration of Ba-137m decay progeny of Cs-137 (662 kev photon peak). Results are reported in picoeuries per gram (pCi/g) of soil. An uncertainty of one standard deviation is reported based on counting statistics alone.
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5 4.
Survey for Exposure Rates The inspectors measured radiation exposure rates at 1 meter from surfaces in the area of the former facility and the trench using a micro-R meter.
Gamma radiation measurements were also taken inside the excavated trenches at grmmd level to identify any localized areas with elevated readings to determine locatiom. for soil sampling.
Localized exposure rates in the trench were measured as high as 30 R/hr on contact with the soil.
No measurements at one meter from any surface exceeded the NRC guideline of 10 R/hr above background. Gross measurements at one meter did not exceed 12 pR/hr and were generally not different from background levels.
5.
Survey for Surface and Removable Conmmination The inspectors surveyed eight of the grids (approximately 5% of the total surface area) l in various parts of the Room 1 and 5 where the most extensive remediation was i
performed. The one meter by one meter grid system established by US Ecology was i
utilized by the inspectors during their survey. The survey was performed by slowly l
scanning the surface with the pancake detector and the range of readings recorded.
Areas with elevated readings of at least twice the average for the grid were noted during the survey and wipes taken in these areas. Attachment I summarizes the surface contamination results.
The inspectors took 4 wipes on various pipes remaining in the trenches and 4 wipes in the former radioisotope inspection facility. Wipes were taken on a portion of the interior and exterior surfaces of pipes that either remained inside the excavated trench or ends I
which extended in the excavation area. The wipes were taken with dry filter paper over 2
an area of approximately 100 cm. After each wipe, the filter paper was placed inside a envelope. Wipes in Rooms 1 and 5 were taken at four locations identified by the inspectors where licensed material was most likely to have been used or at locations with
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elevated surface contamination readings. Wipes were taken in a similar manner as 1
2 described above except that the areas surveyed was greater than 100 cm ; however, all 2
results have been corrreted to per 100 cm. Attachment 2 summarizes the removable contamination results. The location: of the wipes are provided in Figure 1.
The inspectors also surveyed the interior and exterior of two pieces of the excavated drain line which were previously surveyed by US Ecology and determined that they met NRC guidelines for release for unrestricted use. Although the inspectors determined that j
the surface contamination levels meet NRC guidelines, they noted that the pipes contained significant amounts of residual material inside similar to the elevated contamination identified inside a drain line from Room 5 (see Section 6). The inspectors requested that AT&T sample the residual material inside a representative number of the excavated drain lines to measure the Cs-137 concentration to determine if the residual material met NRC guidelines for unrestricted use.
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Subsequent sampling of some of the soil and sediment (as well as corrosion products) from this piping by US Ecology confirmed that this material was contaminated to above the NRC guidelines for soil contamination. AT&T decided to remove the contaminated material from the drain lines and resurvey the drain line walls to determine if any residual contamination was below surface contamination guidelines.
AT&T was evaluating the disposition of this piping at the close of this inspection and vill document their actions to resolve this concern in their closeout survey report.
The NRC's " Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for Byproduct, Source or Special Nuclear Material," dated May 1987, (the " Guidelines") provide criteria for determining whether a facility may be released for unrestricted use. The removable 2
contamination criteria in the Guidelines for Cs-137 are no more than 1,000 dpm/100 cm,
For total surface contamination, the contamination guidelines allow an average level of 2
5,000 dpm/100 cm averaged over an area not to exceed one square meter with a 2
maximum contamination level of 15,000 dpm/100 cm allowed over an area not to exceed 2
100 cm. The results in Attachments 1 and 2 meet the NRC guidelines for release for unrestricted use.
6.
Soil Samples The inspectors took nine duplicate sets of soil samples in the drain line trench. One set of samples were provided to AT&T for analysis while the inspectors returned the other set to the Region 1 office for gamma spectroscopy analysis. Eight of the nine soil samples were taken in the trench were the pipe and surrounding soil were contaminated with Cs-137. The ninth sample consisted of residual material inside a remaining portion of drain line originating from the former radioisotope inspection facility (Room 5) into l
an adjacent trench. Soil samples in the trench were taken with a trowel in the top 15 centimeters of soil. Approximately 1,000 grams of soil was taken per sample and placed inside a plastic bag. The sample from the drain line was taken with a piece of metal to scrape out the residual material from 10 cm diameter pipe. The soil sample results are provided as Attachment 3 to this report. The location of the samples are identified in Figure 1.
The NRC guideline for residual Cs-137 contamination in soil is 15 pCi/g. All soil samples taken in the trench met this criteria. The sample of residual material from inside a branch drain line had a Cs-137 concentration of 103.3 i 0.7 pCi/g which does not meet the NRC guideline for residual contamination in soil. This finding was discussed with AT&T representatives who indicated that they would either clean the line of any remaining soil and sediment or remove the line in its entirety and dispose of it as radioactive waste.
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7 7.
Exit Interview The results of the inspection were discussed with the AT&T and US Ecology representatives identified in Section 1 on June 7,1994 In addition, the inspectors discussed the results of soil and removable surface contamination smear samples taken at the Clark facility with the AT&T Radiation Safety Officer during a telephone conversation on June 22,1094.
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ATTACHMEITT 1 Surface Contamination Survey Results Roem and Grid Location Surface Contaminalind Room 1; Floor - B1 1,800 Room 1; Floor - Cl 1,600 Room 1; Wall - B2 1,100 Room 1; Floor - A5 1,500 Room 1; Floor - B6 2,900 Room 5; Wall - Al 700 Room 5; Floor - C6 2,400 Room 5; Wall - B2 1,300 (a)
Maximum surface contamination above background in dpm /100 cm,
2 2
MDA = 3,600 dpm /100 cm t
ATTACHMENT 2 Removable Contamination Survey Results Number Location Removable Contamination 2
(dpm/100 cm )
1 Two pipes in the trench -
4i2 Far end of east hallway 2
Pipe in the trench - center 4i2 cast hallway 3
Pipe in the trench - corner 4i2 of east / north hallways 4
Pipe from former lab area 2
2
- north hallway 5
Floor grid C Room 5 3
2 6
East wall grid B Room 3i2 5
7 North wall grid B 1 2
Room 1 8
Floor grid B Room i 1i2 MDA = 5.8 dpm per wipe 1
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4 ATI'ACHMENT 3 Soll Sample Analysis Results Number Imation Cs-137 concentration (oCi/c)
I End of pipe from the 103.3 i 0.7 former lab area - north hallway II East hallway trench - east o.065 i 0.011 of control point III East hallway trench - west 0.55 0.03 of control point IV East hallway trench - west 0.08 i 0.02 of control point (just north of sample #3)
V East hallway trench - near 10.59 i 0.08 junction with north hallway hallway trench -
1.01 0.03 VI N
a near junction with east hallway VII North hallway trench 2.8 i 0.05 where drain pipe exits the
+
former lab area VIII Center of north hallway 2.21 t 0.04 trench IX Far end of north hallway 1.11 i 0.03 trench
L Figure 1 l
LOCATION OF SOIL AND SMEAR SAMPLES TAKEN AT TIIE CLARK FACILITY
.c 8
?
x$%
a 3:
3 b
- 6 Room #5 1
- 5
~~
- 2 Control Point A
Room #3 Room #2 E
- IV g
- III 8x
- 8 Room #1
- V
- 4
- I
- 3
- VI North Hallway Trench
- VII
.y111
.gy Soil Samples Locations Denoted by Roman Numerals (e.g. *I)
Contamination Smear Locations Denoted by Alphanumerics (e.g. #1)
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