ML20045F219
| ML20045F219 | |
| Person / Time | |
|---|---|
| Site: | 07000997 |
| Issue date: | 06/15/1993 |
| From: | Kinneman J, Oberg C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20045F215 | List: |
| References | |
| 70-0997-92-01, 70-997-92-1, NUDOCS 9307070104 | |
| Download: ML20045F219 (9) | |
Text
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U. S. NUCLEAR REGULATORY COhmilSSION REGION I Report No.
070-00997/92-001 Docket No.
070-00997 License No.
SNM-951 Priority: 2 Category: A Progmm Code: 22110 Licensee:
Westinghouse Electric Coroomtion -
Post Office Box 355 Pittsburgh. Pennsylvania 15203 Facility Name:
Advanced Enerey Systems Division Inspected At:
12ree. Pennsylvania Inspection Conducted:
September 15.1992 l
Inspector:
1 v7
'f3 C. Thor Oberg, Ildth->fiysicikQ D6te flgned Approved By:
g
/
3 John D.
i neman, ('hief Ifate sig'ned Researcl evelopment, and Decommissioning Section bisoection Summary: Routine. unannounced safety inspection conducted on Sep1e. mber 15.1992 (Recort No. 070-00997/92-00lt Areas Inspectedl Organization and scope of activities; facilities and the location and removal of the Monitored Drain.Line system; monitoring, sampling, and analytical results-radioactively contaminated waste and planned disposition; and projected timing for termination -
of the license.
Besults:
No violations or radiological safety concerns were identified.
-1 9307070.104 930622 PDR ADOCK 07000997 C
ppg
q DETAILS 1.
Persons Contacted
- Andmw T. Sabo A. Joseph Nardi (telephone contact)
- James T. Flanigan Invin Dobrushin Larry Smith Scott Gillespi i
- Those present at Exit Meeting 2.
Site Historv Westinghouse Electric Corporation (E) is authorized by License No. SNM-951 to possess uranium-235, neptunium-237, americium-241, and byproduct material for research and development and for instrument calibation at the Advanced Energy Systems Division (AESD) facility, large, Pennsylvania. Previously, opemtions under this license (circa 1970) at this facility were conducted by the E Astro Nuclear Division.
The E AESD facility at Large, Pennsylvania, is leased from the Dick Corporation who wants the site in its original, contamination-fme state when it is returned to them.
Licensee representatives stated they plan to leave no evidence at the site to identify the fact that nuclear materials were used here.
During 1991, E personnel decontaminated and cleaned two buildings on this site. The licensee requested an amendment to License No. SNM-951 for the release of these buildings to the owner for unrestricted use. The license was amended and Buildings No. I and No. 2 were released to the owner, Dick Corporation. The licensed facility now consists of Building Nos. 4, 5A, 5, 6A, 6, 7, 8, 8A, 9,10,11 and 12 as identified in the enclosed E AESD map dated December 21,1988.
In a letter to Region I dated July 18,1991, E stated that they are proceeding with actions necessary to terminate License No. SNM-951. According to a E letter dated August 14, 1991, preliminary surveys and site historical reviews indicate that only the Monitored l
Drain Line (MDL) system at the Large site requires a significant decontamination effort because of uranium-234 (U-234) and uranium-235 (U-235) contamination. The MDL was a special drain system used as a waste line for liquids containing radioactive -
l contamination. The system conducted contaminated water from various building locations to collection and holding tanks where, if necessary, the water was processed, monitored
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for radioactivity and subsequently released. A schematic layout of the MDL system is detailed in the enclosed E drawing "Large Site, Contaminated Waste Line Drawing M-1" dated February 20,1992.
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. E management is working closely with the site personnel to maintain comprehensive i
oversight. Each week management personnel meet at the facility with the Radiation Safety Officer (RSO) and the site Health Physicist (HP) to review the progmss of the operations.
3.
Removal of the Monitorg(LDrain Line System The probable locations of radioactive contamination within the buildings, based on the type of licensed materials utilized in the area, are delineated in the enclosed, "Large Site Historical Review" dated Febmary 6,1992, that includes a copy of a hand written plan for the physical close-out survey. The E drawing "Large' Site, Contaminated Waste Line., drawing M - 1" dated February 20,1992, shows the layout of.
the MDL system. A reduced copy of this drawing is enclosed with this report. The I
drawing is used by E personnel to identify the MDL sections and for soil sample locations.
According to the E letter dated August 14,1991, the MDL system is the only known system at this site requiring significant decommissioning effort. The analytical report attached to this letter shows that ten samples of sludge or scrapings fro'm the MDL system piping each contain EU in excess of appropriate release limits.
E initiated removal of the MDL system in accordance with the enclosed
" SPECIFICATIONS" for " Removal Of The MDL System". During the removal of the MDL system, radiation monitoring and soil sampling has been conducted in accordance with the enclosed E PROCEDURE NUMBER 001 dated April 16,'1992, Revision 0 (enclosed). Attached to this procedure are full size copies of the M - 1 Drawing in four, 1
8-1/2 in. x 11 in. sections, and a copy of the MDL Trench Soil Sample Index Data.
The MDL piping was removed by excavating and trenching. The pipe _was then cut into sections of reasonable length, removed from the trench and placed into E Model B-25 metal shipping containers. In some locations, the trenches were several feet deep, requiring substantial shoring to inhibit collapse of the trench walls. This was a panicular problem for the removal of piping Sections 20 and 21 going into the holding tank space l
beneath Building 9.
The MDL system has been removed and the trenches have been back-filled, with the exception of: the trench excavated for the removed MDL system pipe _ Section 5; the trench and tunnel for removed pipe Section 7 going into Building 6A; the trenches and tunnels for the removed pipe Sections 9,13, and the partially removed pipe Section 8; and the concrete lined pit (or sump) for the removed holding tank (tank No. 5) outside the
.i nonh end (back) of Building 5; The Building 6A MDL piping passes under a seismic.
J shaker and appears to be buried in the concrete suppon for the shaker. Apparently before the concrete was poured, the MDL was cut and replaced, with the appropriate connections, at a lower depth. Due to the ongoing operations in this building and
. hazards associated with open trenches, the licensee decided to tunnel under this building to remove the piping. The licensee retained the services of consultants with training and experience in tunneling and shoring operations who trained the contractor personnel and inspected both the trenching and tunneling operations. For the tunneling opemtions, the licensee supplies the workers with protective clothing, gloves, and dust masks. Funher, the licensee is supplying fresh, filtered air into each tunnel. During working hours, the licensee is also taking daily Breathing Zone Air Samples (BZAS) using low air flow, personal air samplers at fixed locations inside the tunnels.
As of September 15,1992, MDL pipe Sections identified as 7,9,13, and pan of S have been mmoved and the contractor is working to remove the remaining portions of pipe Section 8 from the concrete beneath the seismic shaker. The licensce representatives asked the NRC inspector if it would be acceptable to decontaminate the pipe section in place instead of removing it from the concrete under the shaker. The inspector agreed 5
that this was acceptable as long as they could verify that residual radioactive contamination remaining in piping meet the appropriate release criteria.
The tanks and pipe sections, plus some other items, are stored in an isolated area on a concrete pad, (beside the site " cell" area) across the site road from the back end (nonh side) of Building Nos. 7 and 8. Drums containing soil, sludge, disposable clothing, small tools, etc., stored inside the " cells", are awaiting shipment for processing and/or disposal as waste. 750 gallon holding tank that was removed from the concrete lined pit in back of Building 5 and the three holding tanks that were removed from the below ground level holding tank room in Building 9, am staged for final disposition along with the B-25 boxes containing the mmoved pipe sections.
When the assay results of trench soil samples showed no significant levels of EU or other radionuclide contamination, the trenches from which the samples.were taken were backfilled and the layers of fill were compacted in acconlance with W PROCEDURE NUMBER 001. The depth from which the pipe sections were removed was marked with a layer of gravel to identify the pipe line location. Thus, if additional sampling is necessary the trench could be reopened to the depth of the MDL. piping without difficulty.
One trench has remained open because a detectable level of activity was found in soil samples removed from this location as discussed in the following Section 4. The location is inside Building No. 5, about 24 feet from the nonh end of the building along MDL -
pipe Section 5. The pipe fitting at this location was a check valve with its upstream connection made to a deep sink. The check valve allowed the sink to drain to the MDL l
but inhibited flow from the MDL to the sink. The MDL piping, valve, and the connecting drain line from the sink were removed, packaged, and are stored in the B -25 boxes for disposal. The trench will remain open until authorization to backfill is received from the NRC.
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.. The licensee is accumulating a libmry of color photographs depicting the AfDL removal operations. In addition, the licensee took photographs of the status of the hiDL system removal on September 15,1992, and gave these _to the NRC Inspector for developing and printing. The photographs were placed in the docket file.
No safety issues were identined.
4.
Acceptable Residual Radioactivity The principle radioactive material that was used under License No. SNhi-951 at the Large, Pennsylvania site was enriched uranium (uranium enriched in the U-235 isotope) that had not been irradiated. Based on this and the results of h1DL residues and deposit analyses, the licensee has established an acceptance level for the release of uranium contamination in soil of 30 picocuries per gram. The acceptance level for the U-235 isotope is established as I picocurie per from of soil. The limit for the U-235 is based on the ratio of 30 to 1 for total uranium to U-235 as was determined by averaging analytical isotopic alpha and gamma spectrometer results. The average enrichment percentage was determined to be about 65 percent.
In addition to the above limits, surface contamination release limits were set at:
Average - 5,000 dpm/100 sq. cm. total hiaximum - 15,000 dpm/100 sq. em. total Removable - 1,000 dpm/100 sq.' cm The release limit for the net dose rate measured at I meter from a surface is:
5 microroentgens per hour net activity.
5.
Personnel hionitoring Whole body, personnel thermoluminescent dosimetry (TLD) badges are wom by the E and contractor personnel working on the hiDL removal. To date, the highest radiation level recorded is a 47 millirem, shallow whole body dose, for a quarterly period. The licensee has installed 150 TLD badges throughout the site for environmental monitoring.
=3 These have not yet been removed and evaluated.
About 100 BZA's, taken at a rate of about 2 each day during tunneling operations, have been analyzed by the licensee using gas-flow proportional counters. The gross alpha and beta results obtained by counting the charcoal from the BZAS were also at the instmment's AfDA levels: 1 to 9 E-12 a-dpm/ml of air and I to 10 E-10 b-dpm/ml.of air (or 0.4 to 4 E-12 a-pCi/ml of air and 0.4 to 4.5 b-pCi/ml of air).
No safety issues were identined.
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6-6.
Soil Samoling During the trenching and MDL removal operations, radiation surveys were conducted in the trenches with an Eberline Instnunent Corp., ESP - 2 ponable survey instmment using i
a 2 in. x 2 in., NaI(TI) gamma scintillation detector (SPA - 3 type) and an alpha / beta probe (HP - 100 type). Double the average count rate on clean material (contact), plus or minus about a 25 percent fluctuation, was established as a trigger level for soil sampling, using this criteria, significantly more surveys and soil samples werc taken than were anticipated. The licensee's survey instmments am being calibrated quanerly.
Soil samples were taken from the trenches at specine locations in accordance with Steps III. 6., 7., 8., and 9. in the W PROCEDURE NUMBER 001. In addition, samples were taken fmm the trenches where there was observed to be a pipe joint or evidence of a possible leak from the MDL (obvious holes in the piping). The soil samples were sent to the W Waltz Mill site for radioassay and radiochemical analyses. Rain (surface)/ ground water samples were taken of the composite water after necessary dewatering of the trenches. Water samples were analyzed at the W AESD site. Sludge from the concrete retaining pit behind Building 5 was analyzed as soil at the W Waltz Mill site. Breathing Zone Air Samples (BZAS) are taken as previously discussed and analyzed at the W AESD site.
The Building 8A trench soil and water sample radioassay results were sufficiently low that the licensee backfilled the trenches. Clean soil 511 was added and compacted. The last several inches of the trenches were filled with concrete and the surface Unished to match the floor of the building. Subsequently, the licensee conducted a close-out type radiation survey of the building using a Ludlum Measurements, Inc., floor monitoring instmment with a Model 43 -37 type, large area, gas proportional detector and a count rate meter Measurements were also made with the Eberline ESP - 2 and the two types of detectors specified in a preceding paragraph. Based on the above mentioned trigger level of double the measurements made on clean materials, no significant level of radiation or contamination was identified. The licensee will conduct a final survey of the area when the site confirmatory survey is conducted. The licensee will be using a new Reuter Stokes survey instmment instead of the ESP - 2, and will employ a recently modified survey grid system.
As of September 15,1991,426 soil samples (plus 2 reanalyzed soils, 3 sludge, and I wire sample) were taken for analysis. Each soil / sludge sample was about I liter in i
volume, thoroughly mixed to attain representative and reproducible samples, and about half of this was retained in storage for reanalysis. For verification of the analytical results, the licensee plans to reanalyze 15 soil samples that showed the highest activity 6
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concentration levels. With one exception, the results of the analytical data showed that the level of U235 contamination in the soil from the tmnches ranged from about 0.25
(+/-50%) to 1.26 (+/-48%) picocuries of U235 per gram of soil (pCi U235/gm). The exception was the analytical result of soil taken from pipe Section 20 at 122 feet from the "L" joint to section 19 (from Building 8A) and just before the "L" joint into Section 21 (to Building 9). Because of the difficulties experienced by contractor personnel working at about a 10 foot depth in this trench, some contamination apparently spilled out of the pipe during the cutting or removal operation. Analytical results of the soil samples (No. 371 and 372) gave an average concentration of 1.5 (+/-20%) pCi U235/gm. About 3 or 4 inches of dirt from this area was shoveled into a 5 gallon dmm and removed from the trench and the soil in the tmnch was again sampled and analyzed. The msults of these analyses (sample Nos. 387 and 388) were equivalent to 0.065 and 0.28 pCi U235/gm of soil mspectively. Based on these results, the licensee concluded that all of the contaminated soil had been mmoved and was contained in the drum. The dmm was sealed and stored with the other waste materials.
4 Analytical data for the trench soil from the MDL pipe Section 5 check valve location Sample No. 85) gave the high concentration of 1.26 pCi U235/gm of soil. On September 15,1992, another soil sample was taken at this location. The sample, No. 432-5-24, was thoroughly mixed and about 1,000 cubic centimeters (cc) of this mixture was split between the licensee and the NRC, Region I, for independent radioassays. Through September 15,1992, a total of 430 soil and sludge samples from the W AESD site at Large, Pennsylvania, have been submitted to the W Waltz Mill Site for radioassay. The licensee has retained duplicates of most of the samples analyzed.
With an assumed ratio of 30 to I for U234 in U235, the licensee estimated the range of U234 contamination in the soil to be fmm 7.5 to 38 pCilgm.
The analyses of three sludge samples (Nos. 419 - 421) taken from the concrete retaining i
pit behind Building 5 (holding tank pit) averaged about 6.6 pCi U235/gm of sludge with a maximum of about 9.8 pCi/gm. The sludge was removed from the pit and deposited in three 55-gallon dmms. The drums have been stored with the other waste material for ultimate disposal.
No safety issues were identified.
7.
Water Sampling When water accumulated from rain and/or ground water, the trenches were dewatered and
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the water was sampled. The water was pumped to above ground retention basins (plastic swimming pools) and held for final disposition based on the results of sample analyses.
About 75 water samples, from min and ground water in trenches and from other MDL system locations, have been analyzed for gross alpha and beta counting by the licensee.
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, l A 5 milliliter (ml) volume for each sample was evaporated and counted in gas-flow proportional counters. The results of these analyses were equivalent to the instrument's minimum detectable activity (MDA) levels: 1 to 5 E-7 alpha disintegrations per minute (a-dpm) and 1 to 5 E-6 beta dpm (b-dpm). These values are equivalent to 0.4 to 2 E-7 pCi of alpha activity and 0.4 to 2 E-6 pCi of beta activity in the water samples. The retained water was subsequently pumped into tank trucks and taken off site for disposal instead of attempting to release it on site.
As of September 15,1992, about 95 percent of the MDL system has been removed, packaged in appropriate containers, and staged awaiting shipment for disposal. About 99 percent of the trenches have been backfilled, as is authorized by the analytical results from soil samples.
No safety issues were identified.
8.
Discovery of Cobalt-60 Wire While monitoring the MDL pipe sections in Building 5, a reading of 2 to 3 milliroentgens per hour (mr/hr) was obtained by the licensee on contact with pipe Section 1. When the piping was cut and removed from the trench, no activity was found in the soil at that location. The pipe section was cleaned and a mdiation level of about 5 mr/hr was measured from the 250-300 milliliters (ml) of residue. The residue was analyzed and the activity determined to be Cobalt-60 from a piece of wire containing cobalt-60. The wire was removed from the residue and retained in storage at the E Waltz Mill Site.
Although byproduct materials including Cobalt-60 have been used at this site, because of the finding of this wire at a dead end of the system, the licensee cannot explain how the wire got into the piping. The adiation from this section of piping is the only significantly high level of radiation measured from the MDL piping system. No other similar levels of radiation have been identified.
No safety issues were identified.
9.
Radioactive Waste The licensee anticipates that during October 1992, they will complete the removal of the MDL system and the packaging of contaminated materials. Contaminated equipment and other waste materials will be staged for shipment and final disposition. This waste I
includes 7 B-25 Boxes containing MDL system piping and fittings; 4 holding tanks; some miscellaneous equipment and items; some 55 gallon and 5 gallon drums of soil; and some 55 gallon drums containing contaminated protective clothing, gloves, small tools, etc.
The licensee plans to ship the accumulated waste materials to the W Systems Engineering Group (SEG) (Hydro Nuclear) in Tennessee.
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9 At SEG, the metallic waste will be decontaminated, processed by melting, and the billets possibly returned, sold as scrap, or retained for shielding. The drums containing' dry waste material will be compacted and transfermd to Barnwell, South Camlina, for burial.
Other containers and drums of materials that do not fit the two preceding categories will be transferred directly to Barnwell for burial.
The licensee will determine to establish the amount of uranium in the waste shipments so that SEG does not exceed their license limits. The licensee's shipment may have to be -
delayed until SEG reduces their uranium inventory, and can accept material again.
No safety issues were identified.
- 10. Projected Timing for Termination of the License The licensee anticipates that they will be able to initiate their final confirmatory survey at the E, AESD site at Large, Pennsylvania, during October or November of 1992. By -
March or April of 1993, the Licensee plans to have their close-out survey completed and evaluated and all contaminated materials shipped for disposal. A request for an amendment to terminate License No. SNM-951 will be submitted to Region I of the NRC along with a copy of the confirmatory survey and an NRC Form 314 cenifying the disposition of materials. The site will be made available for the NRC close-out inspection and surveys. E pmsumes that this will provide sufficient time for the NRC to' complete their evaluation of the facility, release the site for unrestricted use, and terminate the license during the calendar year of 1993.-
- 11. Exit Interview The inspector reviewed his inspection findings with those individuals identified in Section 1 of this repon. To the inspector it was apparent that the licensee is making a sincere and conscientious effon to remove any and all evidence of the use of radioactive materials, authorized by License No. SNM-951, from the E, AESD, Large, Pennsylvania site.