ML20140J264

Draft, Dose Assessment for Kiski Valley Water Pollution Control Authority Kiski Valley,Pa

ML20140J264
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Issue date:	05/31/1996
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i DRAFT i

DOSE ASSESSMENTFOR i

KISKI VALLEY WATER POLLUTION CONTROL AUTHORITY I

KISKI VALLEY, PENNSYLVANIA 6

May 1996 U.S NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS DIVISION OF WASTE MANAGEMENT WASHINGTON, D.C.

9705140030 970429 PDR WASTE WM-3 PDR Enclosure

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o 1.0 Introduction The Kiski Valley Water Pollution Control Authority (KVWPCA) operates a f

wastewater treatment plant in Leechburg, Pennsylvania.

The facility separates solids from raw sewage, which are then dewatered by vacuum filtration.

The dewatered sludge is then incinerated,. sterilized and converted to ash.

From 1976 to early 1993, this ash was mixed with water, forming a slurry, and transferred to an on-site lagoon for storage.

This practice and use of the lagoon was discontinued in early 1993.

Currently, as ash is generated, it is accumulated and disposed of in a municipal landfill on a batch-type basis.

In August 1993, the Pennsylvania Department of Environmental Resources (PADER) notified the U.S. Nuclear Regulatory Commission (NRC) that they had measured elevated uranium activity in a sludge ash sample obtained from the ash lagoon.

In September 1994, PADER provided the NRC a " split" sample for independent analysis. This sample was analyzed by the Oak Ridge Institute for Science and i

Education (0 RISE) and results confirmed PADER's analysis. In September 1994, I

the NRC conducted surface and subsurface sampling in the ash lagoon. Analysis of_the samples from the ash lagoon indicated that some of the samples contained concentrations of enriched u " nium exceeding 900 pCi/g which is higher than unrestricted use guidelines typically used by the NRC for uranium in soil (30 pCi/g).

The KVWPCA is located in Leechburg, Pennsylvania, which is approximately 25 i

miles (40 km) northeast of Pittsburgh.

The ash lagoon is located in the east 2

end of the KVWPCA property and covers approximately 4,000 square meters (m ),

The lagoon, which has a clay liner, is 2 to 3 meters (m) deg)p at the center and currently contains approximately 10,000 cubic meters (m of ash.

The lagoon is surrounded by e berm which is 2 to 3 m high on the north, west, and south sides, diminishing to ground level at the east end.

The property entrance road borders the lagoon to the east and north. The Kiskininetas i

River is located just east and north of the KVWPCA property.

On February 1,1996, NRC and the Pennsylvania Department of Environmental Protection (PADEP) staff met to discuss the possible disposal options for the contaminated ash. The possible disposal scenarios which were developed and discussed included:

No Action Stabilization and Capping On-site Disposal at Parks Township SLDA [ Stabilization In Place (SIP) only)

Disposal at Municipal Landfill Blending On-site Prior to Municipal Landfill Disposal Disposal at Licensed LLW Disposal Facility Beneficial Use Pilot Plant Processing to Recover Uranium To compare and evaluate these disposal options NRC and PADEP needed to obtain information on the possible dose to the public which could result from these options, applicable regulations, licensing and permitting requirements, and additional characteristics of the uranium in the ash.

This report summarizes the assumptions, analyses and results of the dose assessments which were performed for several of the above options.

There was not enough information

s available to the staff, at this time, to be able to perform dose assessments for the Beneficial Use or Pilot Plant Processing options.

In addition, more detailed information will be needed to perform a site specific assessment for the disposal of ash at a local landfill, once a site is selected.

2.0 RESRAD Analysis The staff perf.

~J severa' oE?oM malyw to estimate the potential dose to a member of the public which could result from these burials.

To perform the dose assessment, the NRC staff used version 5.6 of the RESRAD computer code.

This code was developed to estimate potential doses produced assuming a family-farm scenario.

Application of the code requires numerous assumptions of future events of uncertain probability.

The code assumes a family moves onto the contaminated area and uses the land to grow crops and raise their livestock.

Doses are estimated for several potential pathways including:

direct radiation exposure, inhalation of resuspended dust, ingestion of food from crops grown in the contaminated soil, ingestion of milk and meat from livestock raised in the contaminated area, ingestion of fish from a contaminated nearby pond, and ingestion of contaminated water from a well at the site.

The resident family is assumed to drill a well at the site boundary to dra.; water for irrigation, drinking, bathing, and watering farm animals.

The water is assumed to be drawn from the aquifer below the sita at the downgradient edge of the contaminated zone.

2.1 Input Values There are a variety of input values which are required to perform an analysis using this code.

The code itself contains default values for all input values.

For the following assessments site specific values were taken from the ORISE report " Characterization Survey of the Ash Lagoon and Adjacent Property Kiski Valley Water Pollution Control Authority Leechburg, PA", dated May 1995.

In the absence of site specific parameters, default assumptions were selected using NRC Policy and Guidance Directive PG-8-08, " Scenarios for Assessing Potential Doses Associated with Residual Radioactivity",' or the RESRAD default parameters. The resident farmer scenario described in PG-8-08 was used for each RESRAD analysis.

Section A 1 of Attachment A contains a list of the assumptions and site specific information whi:h were used in these analyses.

Each analysis described below used the input values contained in.

Any input salues that varied or were changed for an analysis are contained in the description of each analysis below and are outlined in Sections A.2 through A.5 of Attachment A.

Values from PG-8-08 are contained in Attachment A, Section A.6.

The availability of the uranium, both totally available and readily available, was determined by ORNL (Attachment A.9).

These values were used to calculate a rough estimate of the distribution coefficient (Kd) for uranium on the ash.

Kd is defined as the ratio of the concentration of uranium in the water, and the concentration of uranium in the ash. ORNL performed batch leaching tests on the ash to determine the total concentration of uranium which could be leached from the ash in a worst case acidic environment, and the concentration of uranium which is simply readily available tu the environment under more typical, slightly acidic environments.

The values determined for readily 2

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available uranium were used to determine the LJ for uranium in the ash.

This average value was used in the RESRAD analyses for the Kd of the ab.

The default Kd values were used for the soils for all analysis (Section A.1).

Section A.6 contains informationtregarding volume and activity concentration of the ash.

The estimated volume per concentration range of uranium was estimated using data from the ORISE site characterization report.

Each 1

sampling point given in the site characterization report was assignco a volume based on the proximity of each data point to other sample locations.

In other-words, if the density of sample locations is high in one area of the ash lagoon, the volume assign to each sample would be lower than the volume assigned to samples in a area with a low sample density.

Since site characterization data was not uniformly obtained throughout the lagoon, the volume and concentration for the portion of the ash lagoon that was characterized is assumed to be representative of the remaining ash lagoon.

The volume and average activity concentration per depth in the lagoon was also determined using the same volume per data point method as described above.

Instead of sorting the data points and their respective volumes by concentration, the concentrations were sorted by depth and grouped into four different depth categories.

The average activity concentration and volume were estimated for each depth category as well as the volume of ash needed to blend with each depth layer in order to reach 30 pCi/g.

3.0 Dose Assessment Restits 1

3.1 Dose Assessment for a No Action Scenario This scenario estimates doses which could result from taking no action to remediate the lagoon.

Because of limitation with analyzing several layers of' contamination with the RESRAD code,'only the lower layer of contamination which contains the higher concentrations was analyzed.

it assumes that the top layer (lower concentrations) of the lagoon has been eroded away so that the lower layers are exposed.

It i: also assumed that there is no soll cover or restrictions on future use of the land.

This analysis began with the values in Section A.l.

The average concentration of 367 pCi/g for the lower layers was used.

Since the ash'has an average enrichment of 4%, the 367 was partitioned into 268 pCi/g U-234, 11 pCi/9 U-235 and 88 pCi/g U-238.

Since this scenario represents a no action alternative, it is assumed the site is released for unrestricted use.

Therefore, the residence farmer scenario is reasonable.

Doses were evaluated usi.ig all migration pathways available in the code.

Figure 1 contains the graphical results of this analysis which

-shows a maximum peak dose to be approximately 90 mrem /yr at 580 years.

Both the water independent and water dependant pathways contribute to this dose.

3.2 Dose from Capping Lagoon On-site This scenario represents the possible dose which could result from allowing the ash to remain in the lagoon and placing an engineered cover over the lagoon.

The cap would reduce the infiltration of water into and out of the ash and would thereby reduce the mobility of the uranium in the lagoon.

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scenario also includes the use of some controls to r' strict people from using the area for farming or building a house.

The analysis began with the values in Sections A.1 and A.2.

Again the total volume of the ash in the lagoon with a concentration of 147 pCi/g uranium at 4% enrichment was used.

Since there would be a cap and controls on the site, doses were evaluated for a resident farmer who lived and grew crops next to the capped lagoon but.ed groundwater from a well placed directly ner to and downgradient from the lagoon.

The external gamma, plan.t ingestion, soil ingestion, and radon pathways were not used because it was assumed that institutional controls placed on the site would remain effective for the period of the analysis.

The analysis used a 1 meter soil cover over the lagoon and assumed no irrigation.

The rain fall was also substantially i

reduced t,ecause RESRAD does not specifically evaluate the effects of an engineered cap, only soil caps.

The basic function of an engineered cap is to reduce infiltration, therefore this reduced infiltration was represented by reducing the amount of rain fall. There was also no erosion of the cover.

The depth to the groundwater was kept at 1 meter.

Capping of the lagoon would reduce infiltration, but would not reduce the level of the groundwater in the area because the cap would cover only a limited area.

There is little dose generated for this option during the 1000 year period of assessment (Figure 2).

Again the main cov.ributor to the dose is the consumption of contaminated groundwater.

The water independent pathways are eliminated by the use of the cap and institutional controls.

The groundwater dose is reduced and the peak dose has been delayed until after 1000 years by the reduction of rain fall and by the increased groundwater travel time.

The time of peak dose is very dependent on the time it takes the uranium to j

migrate out of the lagoon, into the groundwater and to travel to the well at the edge of the lagoon.

The timing of the peak groundwater dose can vary by several orders of magnitude depending on the values chosen for the infiltration of water passing through the cap and leaching of the uranium.

3.3 Disposal of Ash at SLDA (only under SIP option)

This assessment is very similar to the on-site capping of the lagoon.

In this scenario, the ash would be moved to the Babcock & Wilcox (B&W) Shallow Land Disposal Area (SLDA) in Parks Township, PA.

This is the site of an old burial site used by B&W to dispose of waste material which was contaminated with uranium and thorium.

The waste was buried in accordance with NRC regulations which were in place at the time the burials were made.

However, that regulation was rescinded in 1981 and the NRC is currently evaluating the best ultimate disposition of that waste.

The waste is located in 10 shallow trenches on-site. The licensee is proposing to stabilize the waste in place (SIP) by covering the trenches with a soil and geosynthetic membrane cap and surrounding the trenches with engineered barriers to keep the groundwater out of the area.

The NRC is currently evaluating this option along with a No Action alterna+ive and a Disposal Off-Site (DOS) option, which would involve removing the waste from the tienches and disposing of it in a licensed low-level waste disposal facility, if the SIP option is evaluated as acceptable for the waste currently at the SLDA, then there is a possibility the ash could be transferred to the SLDA and placed under the cap proposed for 4

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As with capping the ash in the iagoon, there would be a cover over s

the material, and site controls to keep people from building a house tile SLDA.

and the engineered features that were pr; posed for this site (i.e., grout on top of the disposal area.

curtains, slurry walls, hydraulic control, borings) would increase the depth to the groundwater to approximately 30 meters.

Although there is a great deal of site specific information for the SLDA was not used in this analysis.Since general information was used in all of the other assessments in this report, the same general information was used in this scenarios comparably.

This is For example, the same Kds were used for all options.

because site specific Kds for soils or bedrock are not yet known for theIn addition evaluation.

KVWPCA site or for the generic municipal landfill.

possibility that the SIP option will not be approved for the waste at the If another option is chosen for disposal of the waste at the SLDA, a

codisposal a the SLDA would nc+ be available for disposal of the ash.

SLDA.

The results of this analysis showed very little dose extending out to 1000 The peak dose does not occur during this time as a result of the very low infiltration of water through the cap and the increased depth years (Figure 3).

8 The cap systems are not completely impervious and small J

This snail amount of water could carry to the groundwater.

amounts of water do pass through tier.

However, it will take very long i

the uranium to the groundwater eventoilly.Also, this analy.,is assumes institutional c thereby indefinite maintenance of the cap to prevent it from failing.

periods of time.

1 Variations in the effectiveness of the cap can affect the time it takes for It could range from slightly longer the uraait.m to reach the groundwater.than the capping on-site alternative to hu Dose Assessment for Disposal of Incinerator Ash in a Landfill 3.4 For this analysis, the approach and general assumptions in NRC's Generic Do Assessment for Disposal of Incinerator Ash in a Landfill dated September 199 This report provides a generic basis for the characteristics andSe was used.

processes of a typical municipal landfill.

which were taken from this report which were used in the RESRAD analysis.

This analysis was divided into two scenarios:

Dilute Total Volume of Ash Pond into Municipal Landfill Scenario 1 -

Volume Oilute Volume of Ash which contains concentrations of uranium gre.tsr than 30 pCi/g into Landfill Volume Scenario 2 -

was chosen for the volume of a typical municipal 3

The ash would be disposed of in a layer that was assumed to be j),

A volume was 30,000 m Scenario I took total volume of ash in the lagoon (10,000 m landfill.

f assumed the entire ash lagoon was homogenized which resuited in an average o meters thick.

The 147pCi/guraniumanddilutedthisvolumewiththatotgllandfillvolume.

' 000 m with a concentration result was a landfill volume of approximatelyThe uranium in the ash lagoon is appro of 37 pCi/g uranium.

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o enriched uranium, therefore the 37 pCi/g s;as divided into an estimated 27 pCi/g U-234, 1 pCi/g U-235 and 9 pCi/g U-238.

These values were used in the RESRAD analysis which resulted in a peak dose to the public of 23 mrem /yr from the groundwater pathway at 1100 years (Figure 4).

The same analysis was performed for Scenario 2.

For this scenario, all of the ash in the landfill which was t alow the unrestricted release limit of 30 pCi/g was removed and could be disposed of anywhere on-site.

The remainder of the lagoon ash which is above 30 pCi/g woula be mixed and placed in the landfill.

3 This resulted in 36,900 m at a concentration of 41 pCi/g (30 pCi/g U-234, 1 pCi/g U-205, 10 pCi/g U-238) with a peak dose of 26 em/yr at 1100 years (Figure 5).

Both of the above pe:k doses are a result of the groundwater pathway.

4 Although there is assumed to be a thin soil cap on the landfill there would be infiltration of groundwater and a subsequent groundwater dose.

In addition, although no institutional controls were assumed, the water independent pathways contributed very little to the dose.

3.5 Dose to Workers Handling Ash In addition to potential public exposures to the radiation givan off from the contaminated ash, workers who process ano transport the ash may be exposed to radiation.

Internal exposure to workers from inhalation of resuspended ash is of particular concern given the dry, low density of the ash and becau" the uranium emits alpha particles w N pose a hazard when the uranium is ingested or inhaled.

Two inhalation dosc osessments are outlined below: (1) inhalation dose to workers from current ash and (2) inhalation dose to workers transporting ash in the lagoon for final disposal.

In addition, the radiological risk to workers handling sludge by-product material is also addressed.

3.5.1 Dose to Workers from Current Ash Up to this point the analy:

nave focused on the potential risks from the contaminated ash in the lagon. However, the sewer authority is still in operation and continues to produce ash.

Based on NRC's understanding of the process currently used at the KVWPCA, the incineration of the sewer sludge produces a dry ash. The ash is then stored in an outdoor hopper for approximately six weeks and is then transferred to truck for transport to a j

municipal landfill for disposal.

This is possible because the uranium concentrations in this current ash are on the order of 6 to 11 pCi/g, well below NRC's limit for unrestricted use.

Because the ash is dry, a dust cloud of ash suspended in air may be produced when the ash is transferred into the truck. Even though the uranium concentrations in this ash are low, there was concern for the workers who load the trucks and are exposed to the suspended dust.

To perform the assessment it was assumed that a worker would be exposed to the ash dust plume for approximately three hours every six weeks or about 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> a year. This exposure duration is considered an overestimate, because workers are probably exposed to the cloud for a shorter period of time.

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density of the dust cloud has not been measured, a density was assumed.

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.29 of the Federal Code of Regulaticns (CFR) Part 1910 contains'the Occupational Safety and Health Administration's (OSHA) regulations for dust loading in air (29 CFR 1910.1000). OSHA requires the use of a respirator if there is more than 15 milligrams of dust in a cubic meter of air (Section B.1, Attachment B).

NRC understands that the treatment plant workers are not required to wear respirators be:ause dust loading does not reach this limit.

4 Therefope, it was assumed that the density of the dust cloud was a maximum of 15 mg/m.

This also is a conservative assumption because the dust plume is j

probably not this dense, and only a fraction of the dust would actually be taken into the lungs (respirable fraction).

The results of NRC analysis of the current ash sample reported a concentration of about 10.3 pCi/g of uranium in the ash based on alpha spectrometry.

Although previous analysis of the ash samples using gamma spectrometry indicated higher concentrations, the alpha spectrometry results are more reliable because alpha spectrometry measures the concentrations of uranium-234, -235, and -238 directly versus the gamma j.

spectrometry approach which assumes ratios of uranium-234 and -238.

Based of the above assumptions, NRC estimated KVWPCA workers would not be expected to receive a dose of more than aporoximately 1 mrem /yr from inhalation of the dust cloud (Section B.;).

F r reasons cited above, we believe actual doses would be lets than 1 mrem /yr.

For comparison, NRC's public dose limit in 10 CFR 20.1301 is 100 n. rem /yr.

The estimated inhalation j

dose therefore is a very small fraction of the public dose limit.

In addition to assessing the radiological risk from inhalation, the risks i

posed to KVWPCA workers handling sludge were also assessed. Workers handling the sewer sludge before. incineration would most likely have a lower dose than the workers handling the ash.

The uranium concentrations in the sludge would be expected to be lower than in the ash because incineration of the sludge l

reduces the volume of the material.

The uranium concentrations in the' sludge are expected to be lower than 10 pCi/g.

In addition, the greatest radiological risk from uranium is from inhalation.

The sludge before j

iWneration is not usually in a dry form where it is susceptible to i

re:,0spension and therefore, irihalation.

To produce a significant dose to a sludge handler, the worker would have to either be exposed to dry sludge,in a i

cloud and breath it in for several hours over a prolonged period, or ingest several grams of sludge a day.

Based on +he process and NRC's observations at i

the KVWPCA, neither of the above scenarios appears likely.

Therefore, the dose to a worker handling sludge would be expected to be much less than 1 mrem /yr.

3.5.2 Dose to Workers Transporting Ash for Disposal l

All of the options considered for disposal of the contaminated ash in the lagoon, with the exception of the no action alternative, involves mechanical disturbances (i.e., mixing and diluting the ash, processing the ash for beneficial use, etc.) or transporting the contaminated ash off-site (i.e, disposal to LLW facility, to a municipal landfill, or to Parks Township SLDA).

Mechanical disturbances and transportation of the ash results in increased potential for internal exposure to workers from inhalation of resuspended ash.

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To evaluate the inhalation dose to a wnrker, various assumptions were made i

regarding the worker's exposure duration, volumetric breathing rate, and ash re-suspension factors.

Section B.2 of Attachment B outlines the assumptions and information used to estimate the inhalation dose to worker from resuspended ash.

Five ash samples, previously collected by ORISE during site characterization, were further analyzed by ORISE to determine the activity of thc respirable ash particles.

The five samples chosen for analysis were those samples that had the highest activity concentrations.

The respirable mass fraction and activity concentrations are included in Section B.2 of Attachment B.

To simplify the dose assessment, the worker exposure duration for all disposal alternatives is assumed to be 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> per day for 66 days.

For off-site transportation scenarios it was assumed that 20 cubic yard (CY trucks would be usd to transport the entire volume cf De lagoon [10,000 m} (353,100 ft )]

3 or railcars with 250,000 lb maximum railload.

If ten trucks are filled and transported per an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> day, it would take approximately Ef: days to empty the lagoon.

Likewise, if two railcars are filled per day i t would take approximately 53 days to empty the lagoon.

This scenario assumes the same amount of time is required to unload the waste from the truck and railcar.

Therefore, the maximum exposure duration to an individual worker either loading or unloading the ash into a truck or railcar for off-site disposal would be 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> a day for 66 days (528 h)urs).

3 Thevplumetricbreathingrateforanadultisassumedtobe1.25m per hour.

Sincethe8-hourtimeweightedaveragevalueallowedbyOSHAfor total air particulates is 15 mg/m without a respirator, the maximum density ofareguitingashcloudthataworkerwouldbeexposedtoisassumedtobe 15 mg/m. As previously mentioned, this loading factor is very conservative.

Based on the above assumption and the activity of the respirable ash, the l

estimated CEDE per worker for each off-site disposal scenario is 28 mrem (see Section B.2, Attachment B).

The formula for calculating committed effect dose equivalent for inhalation was obtained from NUREG/CR-5512 (equation 6.3).

The offsite cont ination potential from a dust cloud created by mechanical disturbances u. a.a ash lagoon or loading current ash into dump trucks is I

virtually zero and, therefore, the resulting public dose is negligible.

Using a Gaussian atmospheric dispersion model, the most conservative estimated ash concentration factor 100 meters offsite as a result of excavating the ash 3

lagoon is minuscule (2 E-19 g/m ).

This estimated ash concentration in air from excavation of the ash lagoon conservatively assumes a ground-level celease with a 3 m effective plump height, the highest atmospheric stability class, an 8 mph average windspeed and an estimated emission rate of 4 E-05 9./s (See Section B.3). The resulting dose to a member of the public assuming a

'U.S. Department of Commerce, Bureau of Standards Handbook 47, Appendix 1, 1950.

4 2 Personal conversation with Tim Ensminger of Oak Ridge National Laboratory, May 15, 1996.

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1 person is standing 100 meters downwind of the site and continuously inhales this dust concentration for 90 days is extremely low and many orders of magnitude below NRC public dose limit.

These estimates are generally-consistent with surface soil sampling which failed to detect elevated uranium concentrations in soil close to the ash lagoon.

If air releases were significant from off-loading current ash, and occurring over an extended peri;d, elevated soil concentration would be expected.

4.0 Transportation Risks The radielogical risks of transporting the ash to a local landfill and to Envirocare in Utah-were evaluated as well as the non-radiological risks (accidents) involved with this transportation.

4.1 Radiolegical Transportation Impacts The radiological risk evaluated in this analysis consists of:

(1) the dose per truck driver transporting the waste to a local

landfill, (2) the dose to a person (public) in transit behind (beside) the truck, l

(3) the dose to.a person standing beside the truck (at rest),

j (4) the dose to a train conductor transporting the waste to Envirocare, (5) the dose to a person in transit beside the train, and (6) the dose to a person standing beside a railcar (at rest).

Theexposure.rategfortheseconfigurationswerecomputedusingthe MICR0 SHIELD code.

Exposure rates were computed at 2 feet from the end centerline of tne waste, at the side centerline, and at 6 feet from the side centerline.

The position 2 feet from end centerline represents the highest exposure levels within the shipment whicle operator's compartment (both truck and railcar).

The side position at the centerline represents the highest exposure level to a person standing beside the truck or railcar.

The 6 feet side position represents the highest exposure levels to a member of the public driving beside the~ truck or railcar.

The truck and rail sides were assumed to be constructed of 1/8 inch steel.

U.S. Department of Transportation regulations require that the exposure rate in any normally occupied space not exceed 2 mrem /hr and that the exposure rates no+ exceed 10 mrem /hr 2 meters (approximately 6 feet) from the outer lateral surface of the vehicle excluding

. the top and underside of the vehicle.' The exposure rates calculated by MICR0 SHIELD for transportation by truck and railcar are summarized below.

Truck Shipment 2 feet from end (operator's compartment) 8 E-05 mrem /hr 3Grove Engineering, MICR0 SHIELD Computer Code, Version 3.13, June 10, 1990.

'U.S. Code of Federal Reaulations, " Shippers - General Requirements for shipments and Packaging," Part 173 Title 49, " Transportation," Section 441(b).

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Beside shipment 2 E-04 mrem /hr 2 meters from side 4 E-05 mrem /hr Railcar Shipment 2 feet from end (operator's compartment) 2 E-04 mrem /hr Beside shipment 2 E-04 mrem /hr 2 meto > from sidc 1 E-04 mrem /hr Section C.1, Attachment C outlines the assumptions used to calculate the transportation exposure rates and contains the computer output for each MICR0 SHIELD calculation.

Based on these calculation, the exposure rate are far below 00T requirements of 2 mrem /hr within the operator's compartment, 200 mrem /hr at any outer surface of the vehicle, and 10 mrem /hr 6 ft. from any surface.

For truck shipments, it was assumed that 654 shipments would be required to i

transport the entire volume of the ash lagoon approximately 30 miles to the nearest municipal landfill.

Assuming an sverage speed of 50 miles per hour, the trip duration would be 0.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

Assuming that on: truck operator receives a 0.6 hr exposure per trip, the total operator exposure for 654 truck shipments is approximately 3 E-02 mrem, which is far below the NRC's public dose limit of 100 mrem /yr.

To ship the waste by train will require two train shipments consisting of 55 railcars for each shipment.

It is conservatively assumed that each shipment will require four train operators, and the train operators are exposed for 63 hours7.291667e-4 days <br />0.0175 hours <br />1.041667e-4 weeks <br />2.39715e-5 months <br /> (assuming a speed of 40 miles /hr and a distance of 2500 miles).

The exposure to a single train operator from one shipment using the exposure rate at the centerline 2 feet from the end of the railcar is 1 E-02 mrem.

Therefore the total exposure to the four operators for two shipments would be 8 E-01 person-mrem.

Two scenarios are used to estimate public exp-ores from both truck and railcar shipments: (1) an individual is exposea to the wa.te by standing Seside a truck or railcar shipment and (2) an individual is exposed by driving in close proximity to the truck or railcar in transit. Assuming that the longest an individual will stand beside a stationary truck or railcar is 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> the resulting dose would from either the truck or railcar shipment would be 1 E-03 mrem.

In order to receive a dose cacceding the public dose limit, a person would have to remain beside a truck or railcar for more than 17 years.

For the second public exposure scenario, it is assumed that a driver of another vehicle travels beside the truck for the entire trip duration (0.6 hrs) at a distance of 2 meters or travels beside a railcar at 2 meters for a 10-hour period. The driver of the other vehicle would receive an exposure of 2 E-05 mrem per track shipment and an exposure of 1 E-03 mrem per railcar.

The total public dose from 654 truck shipments, assuming a member of the public is driving beside each shipment for the duration of each trip, is 1 E-02 person-mrem.

The total public dose exposure from each of two train 10

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shipments, assuming a member of the public is U iving beside each railcar for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />, is 1 E-01 person-mrem.

a 4.2 Non-radiological Risks Associated with Transportation Accidents The non-radiological risks of transporting the lagoon ash off-site were also evaluated.

These risks included the transportation of the material approximately 30 miles by truck to a local municipal landfill, and the transportation of the material by train approximately 2500 miles to 4

Envirocare.

For _the landfill transportation risk it was assumed that 2p CY trucks were used to haul away the entire volume of the lagoon (10,000 m ).

If 10 truck loads were hauled away per day it would take approximately 66 days to empty the lagoon.

The formula for calculating the probability of an accident occurring and for_ the consequences of those accidents as obtained from NUREG-0170.

The probability of an accident occurring for the removal of the entire ash lagoon by truck is approximately 0.04 for 19,800 truck-miles. (Section C.2, Attachment C).

The same method were used for calculating the probability of an accident for a train carrying this ash to Envirocare in Utah.

It was estimated the lagoon ash would fill.110 average rail cars. NUREG-0170 starts that an average train is 70 rail cars, therefore it was estimated that two shipments of 55 railcars per shipment would be used to transport the waste to Envirocare.

It is approximately 2500 miles from Leechburg to Envirocare with an average risk of a fatal accident of

~ per rail mile.

Therefore the probability of an accident occurring is approximately 0.007 (Section C.3, Attachment C).

There are rail road tracks which pass close to the facility property.

According to the KVWPCA they are secondary tracks which are used only when there are problems on other tracks.

This means the ash can be loaded into rail cars directly from the lagoon and there would be no additional risk from transporting the material from the lagoon by truck to get it to a train.

The radiological exposure to workers from loading the ash into rail cars would be the same as the exposure for loading the ash into trucks.

5.0 Conclusion Based on the above analyses it appears that many of the proposed options are suitable to meet NRC regulations. Attachment D provides a summary of the proposed action and the estimated doses and risks associated with those options.

11 j

4 ATTACHMENT A INPUT PARAMETERS FOR RESRAD CALCULATIONS A.1 Site Specific Inputs Used in all Analyses 3

• Volume of tric.ah lagoon is 10,000 m 2

• Area of ash lagoon is 4000 m

• Thickness of contaminated zone is 2 m

• Average concentration of ash is 147 pCi/g (107 pCi/g U-234, 4 pCi/g U-235, 35 pCi/g U-238) 3

• Density of ash is 0.6 g/cm

• Average Distribution Coefficient (Kd) for ash is 1400 (default for cells)

• Death to the Groundwater is 1 meter

• Unrestricted use (family farmer scenario, PG-8-08)

A.2 Inputs used for the No Action Scenario All pathways open No cover Only lower layers of ash (1 meter thick contamination zone)

Average concentration of 367 pCi/g (268 pCi/g U-234,11 pCi/g U-235, and 88 pCi/g U-238)

A.3 Inputs for tapping Lagoon On-site

• 1 meter soil cover l

• No erosion of the cap, or contaminated zone

• Water dependent pathways only

- drinking water

- inhalation

- meat ingestion

- milk ingestion

- aq"atic foods

• Limited rain fall ( l cm/yr)

• ho irrigation

~

• Institutional Controls

s A.4 Inputs for Disposal at SLDA 2

Area of contaminated zone is 5600 m (1.4 acres) 1 meter soil cover

=

No erosie

f the cover, or contaminated zone a

• Water dependent pathways only

- drinking water

- inhalation

- meat ingestion

- milk ingestion

- aquatic foods

• 30 meters to the groundwater

= Limited ioin fall ( l cm/yr)

• No irrigation

. Institutional Controls A.S Inputs for Disposal in Local Landfill Specifics Contained in Section A.8 Generally

- cover

- 1 meter to groundwater

- irrigation

- no institutional controls l

f I

+

. t

)

/

\\

M. b List of PG-8-08 Scenario C default values Parameter PG-8-08 i

3 Contaminated zone density (g/cm )

1.63 3

Unsaturated zone density (g/cm )

1.63 i

3 Saturated zone density (g/cm )

1.63 I

Contaminated zone porosity 0.3 Unsaturated zone porosity 0.3

)

Saturated zone porosity 0.3 Radon Emanation Coefficient 0.35

{

Irrigation Rate (m/yr) 0.76 Water table drop rate -(m/yr) 0 Unsaturated (uncon'aminated) zone thickness (m) 1 Fraction of indoor time 0.55 Fraction of outdoor time 0.21 j

Milk consumption rate (1/yr) 100 j

Shielding factor for inhalation 0.5 Soil ingestion rate (g/yr) 18.25 Fruit, vegetable, and grain consumption rate (kg/yr) 166*

3 Inhalation rate (m /yr) 10512 Leafy vegetable ingestion rate (kg/yr) 11 Shielding factor for external gamma 0.33 Drinking water intake rate (1/yr) 730

• Based on a contaminated area of at least 10,000 m.

3 i

Note: If not identified in this table or Taole 1, values used are RESRAD j

defaults l

i I

3

4

4 e

i i

A.7 Volumes and Average Concentrations i

. Estimated volume of ash contaminated with specific concentrations of

)

uranium 1

l i

Concentration Est. Volume in m3 pCi/g of U 0 - 30 3100 s

L 30 - 100 2200 100 - 200 1500-

> 200 3200 i

i I

Estimated concentration and volume per depth in lagoon i

Vol (m3) of ash needed Average Vulame i.3 Depth in cm pCi/g U to reach 30 pCi/g 0 - 50 12 3100 0

50 - 100 125 2500 10,000 - 12,600 100 - 160 540 1700 36,000 - 45,600 160 - 200 259 2700 25,700 - 32,500 The volume of-ash needed to reach 30 pC1/g was calculated using the

=

lowest density of the fill ash and the highest density.

Assuming:

3

- A total of 10,000 m ash in lagoon;.

- A density for the ash ranging from 0.25 to 1.5 g/cc;

- current ash concentrations between 6 - 11 pCi/g

- and a production rate'for current ash of 20 tons / month

=Iftheentirelagoonweremixedtheaverageconcentrationwpuldbe 147 pCi/g and it would take an estimated 48,000 to 61,000 m of current ash to bring concentration down to 30 pCi/g.

• It could take between 60 and 250 years to dispose of all of the ash by blending with the current ash

l

~.

t i

2 i

l

{

d,b Important Site Parameters Used In RESRAD Model For The Typical Landfill VALUE AND UNIT

~

I PARA &ETER 100.00 m

-Imagth Parallel to Aquifer 0.6m Cover Depth 0.60 g/cm 8

- Density of Cm aaed Zone 0.40 i

- Cont. Zone porosity 0.20 l

- Cont. Zone EKective Porodty 10.00 m/yr l

- Cont. Zone Hydraulic Conductivity 1.00 m/yr i

- Precipitation Rate 0.2 m/yr I

- Irrigation Rate 0.20 Runoff Coeiracient 1.0 km 2

- Watershed Ans 10.00 m/yr j

- Umsat/Uncont. Zone Hydraulic Conductivity 1.6 g/cm' 1

- Density of Saturated Zone 0.4

- Sat. Zoon Total Foresity 0.20 Sat. Zone Effectne Porosity 100 m/yr

- Sat. Zone Hydraube Conductivity 0.02

- Sat. Zone Hydrsuiic Gradient 7301/yr Drunkang Water Ineske 1

- Drinidag Water Praction 1

- Livestock Water Fracasoa 1

- Inisation Fraction From a Wdi 0 m/yr

- Water Table Drop Rate 29 4

m._

-t s 4 3

c s

t A.9 Environmental Availability s

t 4

i Total Available Uranium Readily Available Uranium C

Leached Quantity Fraction of Leached Quantity Fraction of Total U in

^

Ci/M of Ci/M M

- Sample #

Location Depth,. cm

activity, analyzed.

Total

activity, analyzed, Total

sample, ah pCi/g grams teached pCilg grcms teached pCi/g i

21599 35N.ISE 150-170 658.46 0.1919 25.27 0.912 31.74 5.0014 0.794 0.0440 721.71 l

21600 35N,15E 200-215 518.28 0.2079 21.55 0.741 19.84 5.0009 0.496 0.0283 699.86 21603 30N,15E 160-175 728.16 0.2073 30.19 0.874 22.08 5.0003 0.552 0.0265 833.44 21621 45N,25E 150-170 533.58 0.1918 20.47 0.809 18.40 5.0014 0.460 0.0279 6b9.3G 2162M 6 45N,SE 115-1:0 788.31 0.1922 30.30 0.854 16.99 5.0004 0.425 0.0184 922.85 29D 45N,SE 115-130 878.83 0.1923 33.80 0.952 t

i 1

k b

l t

s I

i

w V

ATTACHMENT B INPUT PARAMETERS FOR WORKER DOSE CALCULATIONS l

B.1 DOSE TO WORKERS HANDLING CURRENT ASH Assumptions

• 11 pCi/g total uranium in current ash

• One truck is loaded every six weeks

• 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> of exposure every loading for a total of 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> /yr i

= 15 milligrams dust in cubic meter of air

• No respirators Result

• Dose is approximately 1. mrem /yr based on RESRAD analysis j

B.2 DOSE TO WORKERS TRANSPORTING ASH FROM LAGOON FOR DISPOSAL Assumptions Exposure duration for mechanical disturbances and transportation -

off-site is 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> a day for 66 days (528 hours0.00611 days <br />0.147 hours <br />8.730159e-4 weeks <br />2.00904e-4 months <br />).

3 Volumetric breathing rate is 1.25 m / hour 3

Maximum Dust Loading Factor is 0.015 g/m.

1

'The uranium contamination is a insoluble uranium oxide and is assigned an inhalation class Y.

l Activity Concentration for Respirable Ash A 0.5 grams aliquot of ash we.s taken from each of five different ash samples previously obtained during site charactcrization of the ash lagoon. The five samples chosen for analysis were those that yielded the highest activity concentration.

1

.. ~.

s The preliminary results of the particle size analysis list the mass and measured activity for each sample stratified by different micron

]

stages as. indicated by the table below.

i 3.

" Range Average vity A ju e

t Stage um air (pCi/g) i 0

9.0 - 10.0 5 E-02 41.7

)

1 5.8 - 9.0 2 E-02 12.8 2

4.7 - 5.8 5 E-02 4.6 3

3.3 - 4.7 1 E-02 14.3 4

2.1 - 3.3 5 E-03 4.95 i

5 1.1 - 2.1 3 E-03 2.96

)

6 0.65 - 1.1 6 E-04 0.33 l

7 0.43 - 0.65 2 E-04

.008 i

To simplify calculations, the data is consclidated into the following particle size groups --

Particle Size Group Particle Size Range 10 um 4.7 - 10.0 5 um 2.1 - 4.7 2 um 1.1 - 2.1 1 um 0.43 - 1.1 Dose conversion factors given in ICRP 30 and in EPA's Federal Guidance Report No. 11, are based on the ar.sumption that the diameters of aerosol particles are distributed log-normally, with an AMAD (Activity Median Aerodynamic Diameter) of 1 um.

Derived DCr for other AMAD values were computed from information given in ICRP 30.5 Calculations i

Since the DCF for U-234, U-235, and U-238 given in EPA's Federal Guidance Report were modified based on AMADs other than 1 um, a committed effective dose equivalent (CEDE) was calculated specific to each radionuclide and micron group as listed in the following table.

To demonstrate, the calculation estimating the CEDE for U-234, U-235, and U-235 ior the 10 um group is illustrated below.

ICRP (1979), International Commission of Radiological Protection, 5

" Limits for Intake by Workers," ICRP Publication 30, Part 1, Annals of the

ICRP Vol.2,-No. 3/4 (Pergamon Press, New York).

e U-234 U-235 U-238.

Exposure Duration (hr) 528 528 528 Breathing. Rate (m3/hr) 1.25 1.25 1.25 Dust. Loading (g/m3) 0.015 0.015 0.015

• Activitv Conc 0 10 um (pCi/g) 38.7 1.6 12.7 Effective DCF (mrem /pCi) 2.66E-02 2.40E-02 2.40E-02 CEDi.(mrem) 10.2 0.40 3.00

~*The Activity concentration at 10 um was determine for each uranium isotope by~ multiplying the Activity concentration by the following percentages --

'U-234-73%

(i.e., 53 pCi/g

• 0.73 - 38.7 pCi/g)

U-235 03%

(i.e., 53 pCi/g

• 0.03 = 1.6 pCi/g)

'J-238 24%

'i.e., 53 pCi/g

• C.24 = 12.7 pCi/g Total CEDE for Worker Exposed to Ash Cloud Activi Micron t

r Group Modified DCF Estimated CEDE (um) mass i

U-234 U-235 U-238 U-234 U-235 U-238 10 53.0 2.66E-2' 2.49E-2 2.40E-2 10.2 0.40 3.0' 5

14.2' 4.80E-2 4.48E-2 4.32E-2 4.9

-0.19 1.5 2

7.85 8.52E-2 7.96E-2

. 7.' 67 E-2 4.8 0.19-0.14 1

0.94 1.33E-1 1.24E-1 1.20E-1

'). 9 0.03 0.27 Total CEDE-(mrem) 27.8 1

+.

3 i

D 1

B.~ 3 Estimated Ash Concentration in Air from Excavation of Ash Lagoon 5

Assumptions

)

j Ground-level release 3 meter effective plume height

)

Class F Atmospheric stability (most stable) a B-mph windspeed g

Emission rate of 4 E-5 g/s i

. Emission rate calculation --

Assumptions Total volume of ash (10,000 m3) is to be transported in 66 days (10,000 m3/66 days = 151 m3 per day)

Average depth excavated by mechanical equipment = 2 m Estimate area of lagoon excavated per day = 76 m2/ day Maximum ash loading factor in air is 0.015 g/m 2

76m / day-Average area of lagoon excavated per day 86400 sec/ day Conversion factor

+

• 3m Effective plume height 0.015 a/m3 Maximum ash loadi ng factor 3.96 E-05 g/sec = 4 E-05 g/s

=

Dispersion calculation

• 0 X(100m,0,0;#)

exp -0.5 *

=

o noy _ o, u.

r gL

Where, 3

X(100m,0,0:H) Concentration along the centerline of plume, g/m ;

H Effective pl.ime height, m; Q

Emission rate, g/s; o,.

Horizontal standard deviation of distribution, m; o,

Vertical standard deviation of distribution, m; and u

Windspeed, m/s The atmospheric dispersion equation and the values for horizontal and vertical standard deviation of distribution were taken from the " Workbook of Atmospheric Dispersion Estimates" by D. Bruce Turner of the Environmental Protectic.n Agency dated 1970.

-0. 5 * [\\3 E.5 m[

3 4 E-19g/m X(100m,0, 0 ; 3 m) exp

= n

• 4 m

• 2. 5 m

• 8 m/ s 2

/,

3 X(100m, 0, 0 ; 3m) = 2 E-09 g/m

l.

4

1. -

l' ATTACHMENT C INPUT FOR TRANSPORTATION RISKS C.1 Radiological Transportation Risks The following. concentration were used to calculate radiological i

transportation impacts based on the estimate average activity j

concentration of 147 pCi/g:

l U-234 107 pCi/g (6.44 E-05 uCi/cc) i U-235 4.41 pCi/g (2.65 E-06 uCi/cc)

U-238 35.3 pCi/g (2.12 E-05 uCi/cc) l Assumptions for Transportation by Truck e

20 CY (cubic yard) trucks will be used for the off-site disposal

=

i alternatives. A 20 CY truck is generally the largest-vehicle that-i-

can meet over-the-road shipping requirements.6 The truck bed width j

is assumed to be 6 ft and the length.'O ft.

The amount of contaminated materiai'in the ash lagoon is 353,100 ft3 (10,000 m3).

The number of truck shipments for the off-site

[.

alternative would be --

4 0 ' UO !E Number of shipments =

20 CY x 27 f t /CY 3

Number of shipments = 654 Assuming the truck shipments will be made in trucks having a 6 ft.

=

width and 30 ft length, the height of the waste in the truck will be 0 'Y * ' 5'

'Y Height =

30 f t x 6 ft Hieght = 3 feet Assumpti ms for Transportation by Rail

'R.S. Means Company, Means Site-Work & Landscaoina Cost Data, Section A12.1-614, 1992.

1

,y

<~

O 9

3 l

Assuming 250,000 lb of waste is the maximum gross railload allowed and the waste has a density of G.6 g/cc, the volume of waste per i

railcar would be --

4 250,000 lb yoy u,,,

3

0. 6 g/cc

• 6 2.43 lb-cc/g-f t i.

i j

Volume = 667 0 m3 4

Assuming the rail shipments will 'e made in railcars having 8 ft.

a width and 40 ft length, the height of the waste _in each railcar would be --

?

60'* 5

Height =

l 4 3 f t x 8 f t.

l i

l Height _ = 21 feet

?

i j

Assuming the maximum height of a standard railcar is 10 feet, the volume of waste per railcar is limited by the maximum railcar height Volume ' 40 f t x 8 f t x 10 f t Volume = 3 200 f t3 110 100-Ton covered hopper railcars will be required for the Envirocare off-site disposal alternative.'Two t ain shipments consisting of 55 railcars will be required to move the ash off-site.

l 353,100 ft)

Railcars -

3200 ft 3 i

1

' Number of railcars = 110

}

I l

46 s

C.2 Non-radiological Transportation Risk Assumptions for Transportation by Truck 1.3 x 10-6 uccidents/km for truck transportation 20 cubic yard trucks a

3 3

10,000 m of ash - 13077 yd of ash Approximately 30 miles (48 kms) to local landfill Calculation 3

3 13077 yd /20 yd / truck = 654 truck loads 654 truck loads /10 loads / day = 65 days 1.3 x 10~6 accidents /km x 50 km/ trip x 10 trips / day x 66 days

= 0.04 or a 4% probability of an acc' dent Assumptions for Transportation by Train e' O.93 x 10"5 accidents /km for train transportation Average of 55 railcars/ train Approximately 2500 miles (4022 kms) to Envirocare Calculation 3

3 13077 yd /82 yd / car - 159 rail cars 0.93 x 10'6 accidents /km x 4022 km/ trip x 2 trips (55 cars each) l

= 0.0077 cr a 0.7% probability af an accident

ATTACHMENT D.1 RISK ASSESSMENT

SUMMARY

7 Timing of Scenario Dose Risk Peak Dose No Action 90 mrem /yr 4 E-05 580 y H

Capping Lagoon On-site 0 mrem /yr in 1000 0

>1,000 y years Disposal at SLDA (SIP only) 0 mrem /

y ar

__ Disposal at Landfill Scenario 1 23 mrem /yr 1 E-05 1,100 y Scenario 2 26 mrem /yr 1 E- 05 1,100 y Worker Dose Current Inhalation Dose

< 1 mrem /yr 5 E-07 Inhalation Dose Transporting Waste 28 mrem 1 E--05 Transporta-ion Risk Impact Truck oferator 3 E-02 person-mrems 2 E-08 Train oferator 8 E-01 person-mrems 4 E-07 Person standing beside truck 1 E-03 mrem 5 E-10 Person standing beside train 1 E-03 mrem 5 E-10 People ' riving beside truck 1 E-02 person-mrem 5 E-09 People uriving beside train 0.1 person-mrem 5 E-08 Non-rad. Transportation Risk (truck) 4.0 E -02 Non-rad. Transportation Risk (rai' car) 7.0 E -03 7Radiation exposure risk are based on a fatal cancer probability coefficient of 5.0 E -04 per rem. ICRP (1991a) International Commission of Radislogical Protection. 1990 Recommendations of the International Commission of Radiological Protection, ICR? Publication 60, Annuals of the ICRP 21 (1-3), Pergamon Press, New York.

n

. - _ _ _.- _ - _=

= _.

i

)

ATTACHMENT D.2 l

CONSIDERATIONS OF THE SCENARIOS Scen. io Cost Public/ Gov limeliness Other Concern Considerations No Action Low Moderate High Close to river

• Used only lower layers in analysis l

Capping Lagoon On-site Moderate Moderate Moderate

• State Permit?

$1-5 M to High 3 yrs

• Analysis only for 1000 years Assumes Institutional Controls remain,in j

place

= Close to river Disposal at SLDA low Low ?

Moderate to

= NRC License Amendment

< $1 M High Analysis only for 1000 years 3-5 yrs

. Assumes Institutional Controls remain in place Only applicable if SIP option is chosen for SLDA Disposal at Landfill Low High low State Permit?

$1 M+

l-2 yrs Analysis only for 1000 years

. A h mixed with entire volume of landfill 3

i

' = Assumes a volume of 30,000 m for landfill 4

Disposal at LLW High Low Low Transportation Risk facility

$10-100 M

< 1 yr Pilot Plant High Low to High Prccessing

> 55 M Moderate j

Beneficial Use Low Moderate Moderate l

2-3 years L

s

.t

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.ap---

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4

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g 9,

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.+

p #%

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UNITED STATES S

",3,,

t gh2M[,{

j

) ?.L iNUCLEAR REGULATORY COMMISSION

'-' k j f..

o

$g 4

i r

wAsnincron. n 2ousoooi p O,-

8 8 // E.

October 4, 1996 g,lcCThy.;},, n J

• '/.'E Mr. William Kirk Bureau of Radiation Protection i

Department of Environmental Protection i

P.O. Box 8469 l

Harrisburg. PA 17120-8469 Dear Mr. Kirk 3

On May 16, 1996, the Nuclear Regulatory Commission staff met with staff of the Pennsylvania Department of Environmental Protection to discuss the regulatory l

options for-final disposition of sludge ash currently stored in an ash lagoon operated by the Kiski Valley Water Pollution Control Authority (KVWPCA).

The enclosed letter c auments the result. of that meeting.

Mr. W. Pounds. Chief.

L' Municipal Waste Division. Bureau of Land Recyciing and Waste Management.

agreed at this meeting to send site-specific information on municipal landfill in the Pennsylvania area to the NRC before the next scheduled meeting of this group. as documented in the meeting report.

The purpose of this letter is to clarify our information needs to facilitate its collection and coc1pletion of'our analyses.

As discussed at the meeting, we plan to prepare a more realistic appraisal of potential exposures to workers and members of the public associated with disposal of the sludge ash in a local landfill.

For this purpose, we request the following data from you for each local landfill that might be a potential site for burial of the sludge ash:

1.

The name and location of the landfill and its distance from the KVWPCA site (necessary to analyze the exposures due to the transportation of the waste):

2.

The annual volume of solid waste that would be disposed of in the landfill, how it would be arranged in the landfill and the physical dimensions of the landfill (necessary to estimate di% tion of the radwaste and its radiological impacts):

3.

The distance from the bottom of the landfill to the water table, if known (necessary to estimate how quickly the uranium could be released from the landfill into the local groundwater); and 4.

The annual precipitation at the landfill site (to estimate infiltration).

Your coments on our preliminary dose calculations, which we have made available to you, are also solicited.

We.will address your comments and refine our estimates of exposure for the landfill option when we receive the abo'te information. We estimate that we can complete our analyses'within two weeks of receipt of this information.

Enclosure s

[

SN

't

' g./'

W Kirk 44 T,

eia< n:

n'

. f, >' ;

In addit!On.

..e request a co?y P-1' '

of 1995. and your appraisal of its > vential npac* on opt!.n, n ie ConSideral100 for KV/PCA Sludge dSn d!5p0Sai l

After we receive the internation and "rpie:e :u analyses. we x11; consult with you t.o schedule a meeting to reste.s our cose a',,es aent-, and continw> ou-(11scuss1ons about tne final dispositian of "m roriamnated,!udge e,h.

2ocereiv.

[ Original signed by]

Michael F. Weber Chief Low-Level Waste and Decommissioning Projects Branch Div'sion of Waste Management j

Of fice of Nuclear Material Safety and SJfegudrdS

Enclosure:

As stateri l

1 i

s