Att_8.1_SLDA_Air_Handling_SOP.pdf

February 2011

Sevenson Environmental Services, Inc.

SLDA Remediation Site

Operations Building Air Handling System Operations and Maintenance Manual and

Standard Operating Procedures

SLDA Site Kiskimere, PA

SLDA Site Air Handling Table of Contents Operation and Maintenance Manual

Table of Contents

CHAPTER 1—OVERVIEW

Basis of Design

Previous Studies Organic Compounds Detected in Soil in Previous Investigations Organic Compounds in Water from Prior Treatability Study

Manufacturer’s O & M Manual

CHAPTER 2—DESCRIPTION, OPERATION AND CONTROL OF AIR

HANDLING FACILITIES

Air Handling Design Intent

Air Handling Design Criteria

Air Handling Component Design

Air Blowers Description Initial Startup Normal Operation Shutdown/Decommissioning/Decontamination Maintenance

Vapor-Phase Carbon Adsorbers Description Startup Normal Operation Shutdown/Decommissioning/Decontamination Maintenance

Supply Louvers Description Normal Operation Maintenance

Residuals Disposal

APPENDIX A--PROCESS DESIGN DATA

SLDA Site Air Handling Table of Contents

List of Figures

Figure 1: Air Blower Drawing

Figure 2: General Blower-Carbon Vessel Arrangement (1 of 4 Blowers)

Figure 3: HEPA Filter Grid Arrangement

Figure 4: Typical Vapor-Phase Carbon Unit (1 of 16)

Figure 5: Typical Louver (1 of 20)

List of Tables

Table 1: Air Handling Design Characteristics

Table 2: Number of Blowers Operating vs. Building Ventilation (Air Changes/Hour) .. 10

SLDA Site Air Handling Chapter 1—Overview

CHAPTER 1—OVERVIEW

The air handling system described in this O&M manual is located in and outside of the

Operations Building on the so-called Shallow Land Disposal Area (SLDA) site, located near Kiskimere in Parks Township in Armstrong County. The site is currently maintained under the Nuclear Regulatory Commission (NRC) License SNM-2001. The site was used as a disposal site from an adjacent facility formerly known as the Apollo

Nuclear Fuel Fabrication Facility, which converted enriched uranium to naval reactor fuel for the US Navy.

The site consists of trenches containing barrels of radionuclide materials, primarily uranium-234, 235 and 238. In addition, other radionuclides found include plutonium 239 and 241, thorium 232, radium 228, and americium 241. The details of the contamination are found in the USEPA Record of Decision (ROD), dated August 1, 2007.

As part of its remediation activities and pursuant to USACE’s Remedial Design, Sevenson will be excavating the trenches on site and removing drums and contaminated soil within the Operation Building. The excavation will be benched, that is, cut back at an appropriate angle, to access the drums and other materials in the excavation, and to provide access for site personnel to scan and monitor remaining soils.

The vapor contained in the excavated soil, containing primarily volatile and semi-volatile organic compounds, will be collected via 4 centrifugal blowers and discharged to activated carbon vessels before being discharged to the outside air.

Basis of Design Table 1 shows the basis of design for the air handling system, for the SLDA project. A description of each component is included, along with the rationale for its utilization.

The proposed treatment process is largely designed to remove volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). Radionuclides will largely be associated with dust and removed via the blower filters.

The design of the system includes redundant units and conservative sizing, consistent with the requirement to operate the plant on a continuous basis.

The air handling design and materials balance for the system is included in Appendix A.

Table 1: Air Handling Design Characteristics

Building Dimensions Length, ft Width, ft Max Height, ft Volume, Cu Ft

2,550,000 Overall Building Ventilation

Cu Ft/Min Air Changes/Hour

200,000

4.7 Blowers

Type Number Unit Capacity, scfm Pressure, inches w.c.

Centrifugal

50,000

8.5 Blower Driver

Type Drive Hp Speed, rpm

Electric motor

Belt

1,180 Radionuclides-Estimated (From Treatability Studies)

Gross Alpha, pCi/L Gross Beta, pCi/L Total Radium, pCi/L Total Uranium, ug/L

40-60 5-30

0.5-4.0 1.5-8.0

Previous Studies Prior to the design of the SLDA air handling system, a literature review was conducted of prior investigations of the site, with particular focus on contaminants that could be volatilized during the processing and removal of material. This material includes soil from the excavation, as well as drums of chemicals and debris buried in trenches on the site.

In addition to the review of prior investigations, water samples were taken from three site trenches for purposes of characterizing the samples for their organic and radionuclide content for treatment. The samples can be used to estimate the chemicals present in the soil in those areas and the particular chemicals that may be associated with the soils in those areas.

Organic Compounds Detected in Soil in Previous Investigations A number of prior studies have taken soil samples from the trenches and from areas around the trenches. The most recent and most comprehensive data were taken as part of the Remedial Investigation (RI) from September—December 2003.

A review of these data by Sevenson showed wide variability of results across the site, and at different sample depths. Volatile organic compounds (VOCs) most often observed at significant concentrations were acetone, dichloroethane, dichloroethane, methylene chloride, trichloroethene, and xylenes. VOC values for these compounds averaged less than 100 µg/L for each constituent.

Semi-volatile organic compounds (SVOCs) were found in much higher concentrations than VOCs, but were also highly variable across the site. Phthalates were most often observed at concentrations averaging 455 µg/L to 1,074 µg/L, for two types.

Organic Compounds in Water from Prior Treatability Study

Sevenson conducted water treatability studies using representative water samples from the site. The treatability studies were conducted at Pace Analytical Laboratory in

Greensburg, PA by Sevenson in January 2010. The treatability studies were the subject of the February 2010 Wastewater Treatability Studies Report., already submitted to

USACE.

The water treatability studies are referenced in this document because they are the most recent samples taken from the site and may be indicative of organic compounds found in the soil within the sample trenches.

The treatability studies showed the presence of low levels (0-20 µg/L) of semi-volatile organic compounds (SVOCs). Volatile organic compounds (VOCs) were localized: two of three sample sites showed little or no VOCs present. One water sample from Trench 7 showed appreciable amounts of 1,1 dichloroethane (504 µg/L), ethylbenzene (1,120 µg/L), and total xylene (5,242 µg/L).

Manufacturer’s O & M Manual A detailed manual describing the specific air handling equipment, its operation, and its maintenance requirements has also been provided. This manual should be read prior to the startup of the facility. The manufacturer’s manual is intended to accompany this manual in the overall operation of the facility. All manufacturer recommendations regarding equipment operation, adjustments, and maintenance should be heeded to maintain equipment warranties.

SLDA Site Air Handling Chapter 2—Description, Operation and Operation and Maintenance Manual Control of Air Handling Facilities

CHAPTER 2—DESCRIPTION, OPERATION AND CONTROL OF AIR

HANDLING FACILITIES

Air Handling Design Intent The air handling system has been designed to pull supply air from outside of the building and discharge all air and any vapors from the soil or drums inside of the building through vapor-phase activated carbon before discharge to the atmosphere.

In addition to processing the organic contaminants before discharge to the atmosphere, the air handling system has also been designed to reduce the exposure of workers in the building to airborne contamination.

Air Handling Design Criteria The following design criteria were used to size the air handling system:

• Building: > 4 air changes per hour

• Louver velocity: 800 ft/min

• Flow through GAC adsorbers: 12,500 cubic-feet-per-minute (cfm) per adsorber

• Multiple blowers to ensure continuous operation of air handling system

Air Handling Component Design The following is a design description of the proposed air handling system for the SLDA project building. A description of each component is included, along with its design rationale.

The proposed air handling system is designed to provide a safe working environment in the building and is largely designed to remove volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs) from the exhaust air via carbon adsorption. The design of the system includes conservative sizing, consistent with the requirement to operate the air handling system on a continuous basis.

Air Blowers Description

Four 100-hp blowers are provided, each with a capacity of 50,000 cfm at 8.5 inches water column. A drawing of the blower is shown in Figure 1. The general blower and carbon vessel arrangement is shown in Figure 2.

Each blower is provided with a coarse pre-filter and a high-efficiency particulate absorbing

(HEPA) filter, designed to remove at least 99.97% of airborne particles of 0.3 micrometers

(µm) in diameter. A photograph of the type of HEPA grid installation at SLDA is shown in

Figure 3.

Replacement filters have been provided. For head loss calculation purposes, a maximum loss

2 inches of water column was assumed to signal the need for filter replacement. Actual experience will dictate how frequently this loss occurs and the filters must be replaced.

Initial Startup

1. Inspect the installation prior to starting each fan. Check for any loose items or debris that could be drawn into the fan or dislodged by the fan discharge.

2. Check the interior of the fan as well. Turn the wheel by hand to check for binding.

3. Check drive installation.

4. Check the tightness of all setscrews, nuts and bolts.

5. Install all remaining safety devices and guards. Verify that the supply voltage is correct and wire the motor. “Bump” the starter to check for proper wheel rotation.

6. Use extreme caution when testing the fan with ducting disconnected to avoid motor overload. Do not run the fan for more than a few seconds if ductwork is not fully installed. Without the ductwork attached, normal operating speed may not be obtained without motor overload. Once ductwork is attached, check for correct fan speed and complete installation. Ductwork and guards must be fully installed for safety.

7. Apply power and check for unusual sounds or excessive vibration.

8. Setscrews should be rechecked in accordance with the manufacturer’s recommendations.

NOTE: Shut the fan down immediately if there is any sudden increase in fan vibration.

Normal Operation

Under normal operation, all four fans should be running to ensure the air handling system is operating at full capacity.

Table 2 shows the impact of operating fewer blowers on the number of building air changes.

Table 2: Number of Blowers Operating vs. Building Ventilation (Air Changes/Hour)

Number of Blowers

Operating

Total Blower Output, Cubic feet-per-minute

Ventilation rate, Air changes per hour

1 50,000 1.18

2 100,000 2.35

3 150,000 3.53

4 200,000 4.71

Check the pressure gages for initial differential pressure across the coarse and HEPA filters to establish the “clean” filter benchmark. Change the filters when the differential pressure is

2 inches of water column.

Shutdown/Decommissioning/Decontamination

Use the proper PPE when removing the coarse and HEPA filters, as they may contain dust contaminated with radionuclides.

Maintenance

The blowers are provided with an O&M manual with the prescribed O&M procedures.

Follow these procedures as instructed to maintain the manufacturer’s warranty for the blower equipment.

Regular fan maintenance should include the following:

1. Check the fan wheel for any wear or corrosion, as either can cause catastrophic failures. Check also for the buildup of material which can cause unbalance resulting in vibration, bearing wear and serious safety hazards. Clean or replace the wheel as required.

2. Check the drive for proper alignment.

3. Lubricate the coupling and the bearings, but do not over lubricate. (See the manufacturer’s manual for detailed specifications).

4. Ceramic-felt shaft seals require no maintenance, although worn seals should be replaced. When lip-type shaft seals are provided, lubricate them with "NEVER-

SEEZ" or other anti-seize compound

WARNING: Do not remove or loosen the fan hub from the fan wheel. Removing or loosening the fan hub from the fan wheel will cause imbalance and void the warranty.

Figure 1: Air Blower Drawing

Figure 2: General Blower-Carbon Vessel Arrangement (1 of 4 Blowers)

Figure 3: HEPA Filter Grid Arrangement

Retainer Rod & Clamping Mechanism

HEPA Filter and Gasket

Vapor-Phase Carbon Adsorbers

Sixteen 20,000-pound adsorbers are provided, with a total of 320,000 pounds of carbon, in order to process 200,000 cfm of exhaust air from the blowers, Each blower will discharge through 4 adsorbers, ducted in parallel. Each adsorber will treat

12,500 cfm before discharging to the atmosphere. A typical drawing of a carbon adsorber is shown in Figure 4.

Typical design values for face velocities for vapor-phase carbon units are 40-80 feet-per minute (fpm). At 12,500 cfm, the calculated face velocity for the 8 x 30-foot vessel is 52 fpm.

Startup

Ensure that carbon media is level. Use a garden rake to level.

Normal Operation

There are 4 adsorbers ducted in parallel to each blower. The ducting has been sized to distribute the airflow evenly to the 4 adsorbers, 12,500 cfm per adsorber. Each adsorber uses a horizontal bed of granular vapor phase activated carbon. Influent vapor from the blowers enters through two duct fittings located on one end of the adsorber.

The vapors are then distributed throughout an open area in the bottom of the adsorber.

Influent vapors flow upward through the carbon bed and into the headspace of the adsorber and then into the discharge ducts.

Normally, all vessels will be used when a blower is operating.

Shutdown/Decommissioning/Decontamination

Spent carbon can be removed by using a vacuum source, generally supplied by a vacuum truck. Upon arrival of the truck, the following steps should be taken.

1. Open the hatches and the end door.

2. The vacuum source is generally connected by a hose to a section of plastic pipe, which is inserted into one of the top openings on the adsorber. Any metal fittings should be protected from touching the plenum and sides of the adsorber in order to prevent damage.

3. Move the pipe around as the carbon level is lowered. The adsorber may require entry to remove any residual amounts of spent carbon. Follow appropriate OSHA confined space entry procedures to prevent worker injury.

4. Thoroughly inspect the interior lining and plenum material for damage once all of the carbon has been removed.

If the interior lining is undamaged and the plenum material intact, the adsorber can be filled in accordance with the manufacturer’s instructions.

Maintenance

These units are designed to require minimum maintenance. The following items should be inspected and maintained as noted:

1. Internal inspection of the lining and polyethylene plate should be performed each time the carbon is removed.

2. Inspect all attachment hardware for damage

3. Check for moisture accumulation by removing drain plugs at least every 2-3 months.

4. Check inlet pressure periodically to insure proper operation.

5. Inspect process connections periodically for signs of wear and/or leakage.

Figure 4: Typical Vapor-Phase Carbon Unit (1 of 16)

Supply Louvers

Twenty supply louvers are installed to supply all inlet air, with the worst-case assumption that all building doors are closed. Each louver is 25 square feet, with 70% clear openings. The louvers are equipped with a bird screen to prevent birds and debris from entering the building. Each louver handles 10,000 cfm, at an average face velocity of 800 ft/min. A drawing of the louver provided at SLDA is shown in Figure 5.

Sixteen supply louvers are located at two elevations on the south side of the building, the opposite side of the building from the blowers and inlet plenum. The lower louver elevation is approximately 3 feet above grade to capture any vapors that are heavier than air. The lower louvers will be located between the bin blocks and sediment piles to avoid creating dust in the building. The upper louver elevation begins at approximately 10 feet above grade to pull air over the piles to the inlet plenum.

In addition, to the 16 louvers on the south side of the building, four supply louvers are located on the east and west walls of the building, two per wall. These louvers are located 3 feet above grade.

Normal Operation

The louvers are adjustable from 0 degrees (fully closed) to 90 degrees (fully open).

Normally, the louvers should be kept fully open.

Keep all equipment, debris, and soil away from the louvers on the outside of the building to maintain a clean airflow into the building. Avoid positioning soil or equipment near the louvers on the inside of the building. Soil pile bins will be located so as not to hinder air flow across stockpiled materials to the air plenums. Soil stockpiles will be covered with 6 mil polyethylene, to minimize air borne dust particulates drawn by air handling system.

Maintenance

Check the louvers regularly for paper, plastic or other debris and remove from the louvers to permit a clean airflow through the louvers.

Figure 5: Typical Louver (1 of 20)

Residuals Disposal Spent vapor-phase carbon will be disposed of with the excavated material as required.

SLDA Site Air Handling Appendix A—Process Design Data

Appendix A--Process Design Data

SLDA Site Air Handling Appendix A—Process Design Data

SLDA Building Vapor Phase Carbon Design Comment

Design Air Flow Rate, cfm 200,000 4.7 air changes per hour Total Operating Hours/week 40 Total airflow per week, cu ft 480,000,000 Assumed VOCs, ppmv 5

Maximum Face Velocity, fpm 80

Vapor Phase Adsorbers Number 16 Pounds Carbon/Unit 20,000 Total Carbon Provided, Lbs 320,000

Carbon Unit Dimensions, Ft Length 30 Width 8

Unit Area, sq ft 240 Total Area, sq ft 3,840

Actual Face Velocity, fpm 52.1

Adsorption capacity, lb / lb 0.25 Total Pollutant Adsorption Capacity, lbs 80,000 Max VOCs in Airstream (mg/m3) 20.47 DCE VOC Loading Rate lbs/week 613.4

Total Weeks Operation to Exhaustion 130

Manufacturer’s O & M Manual

Residuals Disposal

Appendix A--Process Design Data