ML20141G860
| ML20141G860 | |
| Person / Time | |
|---|---|
| Issue date: | 05/19/1997 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20141G851 | List: |
| References | |
| REF-QA-99990004-970519 99990004-97-01, 99990004-97-1, NUDOCS 9705230038 | |
| Download: ML20141G860 (9) | |
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E_N_ CLOSURE U.S. NUCLEAR REGULATORY COMMISSION REGION IV Docket:
999-90004 License:
Not Applicable Report:
999-90004/97-01 Licensee:
Not Applicable Facilities:
Sheffield Steel Corporation, Sand Springs, Oklahoma Zinc Corporation of America, j
Bartlesville, Oklahoma
]
Twelfth Street Scrap Company, Joplin. Missouri Dates:
February 11-March 7,1997 Inspector:
R. A. Brown, Senior Radiation Specialist Approved:
L. L. Howell, Chief Nuclear Materials Inspection and Fuel Cycle / Decommissioning Branch Division of Nuclear Materials Safety i
Attachments: 1. Supplemental inspection Information
- 2. Photographs i
9705230038 970519 PDR GA999 ENV*****
99990004 PDR
. EXECUTIVE
SUMMARY
NRC Inspection Report 999-90004/97-01 This reactive inspection was conducted in response to notification of an incident involving a nuclear density gauge discovered at a steel reprocessing company in Sand Springs,
- Oklahoma, 1
inspection Findings-Sheffield Steel An incoming load of scrap steel triggered radiation detectors at Sheffield Steel on February 7,1997. A nuclear density gauge in the load of scrap was identified as the source of the radiation. The inspection determined that the gauge originated at the Somex plant in Bartlesville, Oklahorna, and was transported to Sheffield Steel via Twelf th Street Scrap in Joplin, Missouri. During the inspection, interviews were conducted with allindividuals involved in the scrap handling process and who might have been in proximity to the gauge to determine time and distance near the gauge.
(Section 2)
)
Inspection Findings-Somex/Zine Corporation of America The inspection found the Somex plant in the process of demolition. The Somex plant had been purchased in 1990 by Zinc Corporeion of America (ZCA). Information obtained during the inspection indicated a him probability that only one gauge had i
been installed at the Somex plant. (Section 3)
Inspection Findings-Twelfth Street Scrap A review of how scrap steel is processed at Twelfth Street Scrap was conducted.
This particular load of scrap steel, containing the gauge, was apparently processed in approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. (Section 4)
Dose Estimates Dose estimates performed by the inspector indicate that the highest exposure to one individual may have been '25 millirems. Exposures to other individuals involved were calculated to have been substantially less than 125 millirem.
(Section 5).
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i ReDort Details 1
Notification l
On February 10,1997, the NRC Region IV office was notified by Sheffield Steel, Sand Springs, Oklahoma, (Sheffield) that a rail car containing scrap metal had triggered radiation screening equipment upon arrival at Sheffield's yard on February 7,1997. Af ter removing scrap from the rail car with an electromagnet, a Sheffield representative isolated a device identified as a nuclear density guage using a survey instrument equipped with a sodium iodide detector. An additional survey with an instrument equipped with a GM detector measured radiation levels of 200 milliroentgens per hour (mr/hr) at the gauge surface near the partially opened shutter.
A tag on the device identified the device as a Texas Nuclear Model 5190 gauge containing 200 millicuries of cesium-137, 2
Inspection Findings-Sheffield Steel 2.1 Insoection Scoce (IP 87100, 83822. 87103) l The inspector conducted interviews of Sheffield employees to gather information concerning the discovery of a nuclear density gauge. in addition, raation level j
measurements were taken at the surface of the gauge.
2.2 Observations and Findinas On February 7,1997, a gondola car (rail car) arriving from Twelfth Street Scrap Co.,
Joplin, Missouri, triggered radiation monitors at the Sheffield facility. After sending the car through the detectors a second time and the alarms were triggered again, the car was flagged as " radioactive" and side tracked so surveys could be performed.
During the process of side tracking the car, it derailed. An electromagnet was used to remove scrap from one end of the car, lightening it, so that a mobile crane could set it back on the track. The scrap was removed by dump truck to an area approximately 100 yards from the car. The scrap removal process took about 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. This process did not involve employees handling the material directly; an electromagnet was used.
A survey of the partially empty gondola car on February 10,1997, indicated no radiation levels above background. The two surveyors, who had been trained in basic survey techniques, then went to the pile of scrap removed from the gondola and located an object that pegged their survey meter, equipped with a sodium iodide detector, at 2.5 mr/hr. The surveyors immediately notified the Manager, Health and Safety, who identified the device as a nuclear density gauge. An additional survey with a GM detector indicated readings greater than 200 mr/hr in the area of the partially open shutter. The Manager, Health and Safety roped off the area and notified the NRC Region IV office of the staff's findings. After notification was
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provided to the NRC, the gauge was then placed in a 5-gallon bucket lined with lead sheet. " Radioactive Material" labels were affixed to the bucket.
The inspector noted a metal tag on the gauge containing the following information:
Texas Nuclear A Division of Ramsey Eng:neering S/N 8 2829 Series: SC Date Meas.11/80 Isotope:CS-137 Amount: 200 mci Tag # DE/DX/DT-4496 On February 11,1997, the inspector, along with representatives of the State of Oklahoma Department of Environmental Quality, interviewed Sheffield employees and inspected the gauge. The inspector noted some damage to the gauge, particularly in the area of the shutter (see photographs in Attachment 2). The shutter was noted to be partially open. Using an ion chamber, the inspector measured a maximum reading of 500 mr/hr at the surface of the gauge near the shutter. The gauge was placed in a smalllocked building to await disposal by the manufacturer.
The NRC Region IV office staff conducted a background review and communicated to the on-site inspector that Texas Nuclear had records indicating this gauge had originally been sold, under the terms of a general license, to a facility formerly owned j
by the Somex company in Bartlesville, Oklahoma. Texas Nuclear's records indicated only one gauge had been sold to Somex. At this point, the inspection was expanded to include the Somex facility to confirra that no other gauges were present or had j
been released.
3 Inspection Findings-Somex/Zine Corporation of America 3.1 Inspection Scone (IP 87100, 83822)
The inspector interviewed Zinc Corporation of America (ZCA) personnel to determine the relationship of their facility to the Somex plant and whether they had any knowledge of additional nuclear density gauges on-site, 3.2 Observations and Findinas Upon arriving at the Somex site in Bartlesville, Oklahoma, on February 11,1997, the inspector noted that the facility had been almost completely dismantled; all that remained were concrete pads and three piles of scrap metal that were being loaded I
on to railcars. Adjaaent to the Somex facility was the Zinc Corporation of America (ZCA) plant, which was also being demolished.
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y 5-On February 12,1997, the inspector interviewed the engineering and maintenance manager for ZCA and learned the Somex plant had been purchased by ZCA as a
" buffer" property in 1990. The engineering and maintenance manager stated that to the best of his knowledge, Somex began operation in early 1981 and ceased operations after 21/2 to 3 years. Somex's ownership from the time the plant was shutdown until ZCA's purchase in 1990 is unclear. ZCA did not operate the Somex plant and only used one small building as a storage facility. ZCA was not aware that any nuclear gauges were located in the Somex plant.
At the request of ZCA, the inspector surveyed two rail cars containing scrap metal being prepared for shipment, in addition, the scrap piles remaining at the Somex facility were surveyed. No radiation levels above background were detected.
in addition, the inspector interviewed the president of Remediadnn Services, Inc. (RSI), the company performing the demolition of the Somex f acility. The president stated that he had conducted three walk-throughs of the Somex plant prior to demolition. This is done routinely to identify potentially hazardous materials. The president stated the gauge was not observed during these walk-throughs. According to RSI's president demolition of the building was performed with metal shears mounted on a boom, thus the equipment operator was approximately 15 feet from the material being cut. It was also learned during the interview that all scrap metal from the Somex plant was shipped to Twelfth Street Scrap Co. in Joplin, Missouri.
4 Inspection Findings Twelfth Street Scrap 4.1 Inspection Scone UP 87100. 83822)
The inspector conducted interviews with Twelfth Street Scrap personnel to determine the process used in handling the receipt and transfer of scrap metal.
Observations of the scrap process were also made.
4.2 Observations and Findinas The manager of Twelfth Street Scrap Company in Joplin, Missouri, was interviewed at this f acility on February 13,1997. The manager indicated this f acility processes approximately 130 tons of scrap per day. Scrap materialis normally off-loaded from in coming trucks with a grapple and placed in a large pile. An electromagnet is then used to separato ferrous and non-ferrous materials. As this separation occurs, two workers remove, by hand, the non-ferrous items. The remaining materialis then placed into large shears with the electromagnet to be cut up for volume reduction.
From there the scrap metalis placed into railcars.
The manager stated that the process from off-loading the truck to placement on the railcar takes approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The railcars are normally surveyed with a microR meter prior to leaving the yard, but a survey was not done in this case due to
l an injury to the person who normally does the survey. The manager also confirmed that all the scrap from the Somex plant was sent to Sheffield Steel.
5 Dose Estimates 5.1 Inspection Scoce (IP 87100,83822)
Interviews with employees at all three facilities were conducted for time and distance estimates to evaluate potential exposures.
5.2 Observatiqns and Findinas Sheffield performed dose estimates for Sheffield employees involved in this incident.
The time estimates used appear accurate as confirmed by the inspector's interviews of the employees. However, for this report the dose rate measured by the inspector, 500 mr/hr, was used to calculate individual whole body doses as opposed to the 200 mr/hr measured by Sheffield. It should be noted there are uncertainties in performing dose estimates in this case. While it is known that the gauge shutter was not fully closed, it is not known when the shutter was damaged. Also, the orientation of the gauge and therefore the dose rate to an individual is unknown.
As noted in table 1, dose estimates range from less than two millirems to 125 millirems, using conservative values for time and distance. These values are well below the limits identified in 10 CFR 32.51 for accident conditions relating to use, storage or handling of generally-licensed devices.
l 5.3 Conclusions Although one Sheffield employee may have received a dose greater than allowed for members of the general public, it is likely that his dose was less than 100 mrem and in the worst case, the dose was below the applicable limit established for accident conditions relating to use, storage or handling of j
generally-licensed devices. The gauge was removed from Sheffield Steel by the manufacturer on February 20,1997. A leak test performed prior to shipment indicated removable contamination of less than 0.00039 microcuries.
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TABLE 1 t
PERSONNEL TIME NEAR GAUGE DISTANCE FROM ESTIMATED GAUGE EXPOSURE-(PflLLIREMS)
Individual A 15 minutes O to 3 feet 13.8 to 125 Sheffield Steel i
individual B 5 minutes O to 10 feet 0.0 to 4.6 i
Sheffield Steel Individual C 10 minutes O to 3 feet 9.2 to 83 Sheffield Steel Individual D 60 minutes 3 feet 55 l
Sheffield Steel
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i Individual E 60 minutes 3 feet 55 Sheffield Steel Individual F 30 minutes 15 feet
<2 Sheffield Steel
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Individual G 3 minutes 5 feet
<2 Sheffield Steel i
individual H 120 minutes 10 feet
<2 Twelf th St. Scrap individual i 120 minutes 10 feet
<2 Twelfth St. Scrap
- Dose calculations for this table assume a surface dose rate of 500 mr/hr.
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8 Exit Meeting Surnmary The inspection findings, as noted in the report, were discussed with Sheffield Steel during a telephonic exit briefing conducted on March 7,1997, Sheffield Steel representatives acknowledged the findings as presented. The inspector asked Sheffield Steel whether any materials examined during the inspection should be considered proprietary. No proprietary information was identified,
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ATTACHMENT 1 SUPPLEMENTAL INSPECTION INFORMATION PARTIAL LIST OF PERSONS CONTACTED Sheffield Steel Douglas Strickland Mike Lawrence Gary Smith Gary McGuire Frank Williams Alvin Farley Calvin Eubanks Steve Johnson Philip Board Zinc Corporation of America Larry Mills
' John Knapp Remediation Services Inc.
Grant Sherwood Twelfth Street Scrap Company Greg Fauvergue Andy Garver Shaun Hency State of Oklahoma Department of Environmental Quality Mike Broderick Pam DeWoody
' Indicates those personnel contacted by telephone only.
INSPECTION PROCEDURES USED IP 87100: Licensed Materials Program IP 87103: Inspection of incidents at Nuclear Materials Facilities IP 83822: Radiation Protection
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Photograph 1: Damaged Nuclear bauge l
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l Photograph 2: Close up of Damaged Nuclear Gauge i
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