Tank Vapor Control Strategy
Yes. The Tank Vapor Information Sheet (TVIS) is posted in the change trailers and on the Industrial Hygiene (IH) website. The TVIS is a communication tool prepared by IH to communicate vapor hazards, Tank Vapor Chemicals of Potential Concern (COPCs)/Chemicals of Concern (COCs), Tank Vapor Watch List Chemicals (coming soon), and emission points (EPs) in a specific Tank Farm.
TVIS Posted in a Change Trailer
The WCs are designed for easy worker hazard recognition/communication and implementation of Tank Vapor control sets. The WCs are categories based on the Tank Farm operating configuration and the work activity’s relationship to a Tank Vapor containing system.
Tank Vapor Intrusiveness is a work activity’s relationship to a Tank Vapor containing system. It is asking the question “When I enter a system/space, will there be Tank Vapors?”
To determine that, one answers the question “is there a known or potential open/direct path to Tank Vapors without a validated engineering control?”
Determining Tank Vapor Intrusiveness is determining the potential exposure to Tank Vapors.
Non-Tank Vapor Intrusive = Low potential for Tank Vapor exposure
Tank Vapor Intrusive = Potential Tank Vapor exposure
TFC-ESHQ-IH-C-48 Definition:
Tank Vapor Intrusiveness. A work activity’s relationship to Tank Farm headspace-connected or Tank Vapor containing systems regarding the potential exposure to Tank Vapors.
NOTE: If a system/space normally contains Tank Vapors; however, an engineering control has been applied and validated, the work activity is categorized as a Non-Tank Vapor Intrusive Activity.
Non-Tank Vapor Intrusive Activity- Work activity that does not intrude/breach a Tank Vapor containing system/space.
Tank Vapor Intrusive Activity- Work activity intruding into a tank, tank headspace, or tank system (Tank Vapor containing system/space) creating an open pathway to the tank vapor source (i.e., WITHOUT engineering controls applied to reduce exposure hazards).
Each WC has a corresponding Tank Vapor Control Set applied that defines:
- Engineering controls
- Monitoring requirements
- Boundaries and postings
- Minimum respiratory protection requirements.
Refer to TFC-ESHQ-IH-C-48 Attachment F for a crosswalk of the Tank Vapor controls.
No. The configurations mentioned in TFC-ESHQ-IH-C-48 are Tank Vapor Standard/Non-Standard Operating configurations. The “tank waste containment is intact” is in reference to the above ground tank waste containment, the known emission points (EPs). More detail on these selections is provided in TOC-IH-58435 Appendix F and TFC-ESHQ-IH-C-48:
The first determination when assigning a [Tank Vapor Work Category (WC)] for an activity is the facility operating configuration. WCs 1-3 apply to Tank Farm facilities in their “standard operating configuration”. Under WC 1-3, all Tank Farm equipment is in a configuration where Tank Vapor EPs are adequately controlled. WC-4 applies to Tank Farm facilities in “non-standard operating configuration”. Under WC-4, Tank Vapor EPs may not be adequately controlled at the exposure source. This results in the need for additional controls until the farm configuration is restored to a normal operating status.
No. The facility status component of the Tank Vapor Work Category (WC) selection is based on the baseline configuration prior to starting work. If a work scope changes the configuration, the potential emission points (EPs) are known and controlled via the work activity portion of the WC categories.
When an EP is created for a work scope, the area will be controlled or posted as an Exclusion Zone (EZ) until an engineering control is applied and validated via direct reading instrument (DRI) monitoring to be effective. Section 4.5 of TFC-ESHQ-IH-C-48 provides details on this process.
The Tank Vapor control strategy is a “trust but verify” system. If conditions in the field were not as anticipated, administrative controls (in this case, monitoring) are in place to alert the workers.
Tank Vapor Work Category (WC) Monitoring Requirements:
WC-1 (General Farm Entry)
When entering a Tank Farm, workers are required to have a Personal Ammonia Monitor (PAM), or equivalent as directed by an Industrial Hygienist, as an indication of changing conditions.
WC-2 (Work inside Tank Vapor space WITH validated engineering controls)
Ventilation as Engineering Control [WC-2a (Active)]
Continuous Industrial Hygiene Technician (IHT) direct reading instrument (DRI) Monitoring: Monitor exposure source (threshold of system breach) to validate the effectiveness of engineering control. Monitor worker breathing zone to ensure exposure does not exceed the Action Limit (AL).
Isolation as Engineering Control [WC-2b (Active) WC-2 (Passive)]
Intermittent IHT DRI monitoring: Perform initial DRI monitoring of exposure source to validate the effectiveness of engineering control. Perform intermittent monitoring of exposure source thereafter.
WC-3 (Work inside Tank Vapor space WITHOUT validated engineering controls)
Continuous IHT DRI monitoring: Monitor exposure source (e.g., breather outlet). Monitor worker breathing zone to ensure exposure does not exceed the maximum use concentration (MUC) of respiratory protection equipment (RPE).
WC-4 (Work inside Tank Farm boundary during non-standard operating conditions)
Continuous IHT DRI monitoring: Monitor worker breathing zone to ensure exposure does not exceed the MUC of RPE. Monitor work area for indication of fugitive emission sources.
Actively Ventilated Farms WC 1-3
Vapor Monitoring and Detection System (VMDS) or VMDS Alternate Monitoring as an indication of changing conditions.
The use of controlled in the text above, and throughout the Tank Vapor documents, means engineering and/or administratively controlled.
Under WC 1-3, the farm is in its standard operating configuration. Therefore, all emission points (EPs) are known and have either been demarcated with a physical barrier and signage or are attended with continual control and direct reading instrument (DRI) monitoring (refer to TFC-ESHQ-IH-C-48 Section 4.5). Inadvertent worker exposure will not occur.
During non-standard operating conditions (WC-4), the location of all EPs is not known and/or they are not posted to inform workers of the EP. Therefore, under WC-4 conditions, the EPs are not adequately controlled, and the entire farm is administratively controlled as a temporary Exclusion Zone (EZ).
No. The examples listed in TFC-ESHQ-IH-C-48 (TF-AOP-005, TF-AOP-011) are not automatically WC-4 work activities. However, depending on the conditions encountered during those abnormal responses, they may be categorized as WC-4. The determination would be made by the responsible Industrial Hygienist and based on if they upset condition has the potential to result in uncontrolled Tank Vapor exposure. Refer to Event Response FAQs for more details.
Essentially, all WC-4 activities (active and passive) are classified as such because conditions within the farm are not as we expect and/or not adequately controlled. Therefore, we do not know for certain where all the emission points (EPs) are. The area/farm is not in the planned configuration and there is a potential for inadvertent tank vapor exposures.
Based on conditions, we may control the entire farm or a localized area as a temporary Exclusion Zone (EZ) until all the EPs are known and adequately controlled.
WC-4 in passively ventilated farms is very uncommon compared to the actively ventilated farms.
No. Different evolutions of an activity may change its relationship to a Tank Vapor containing system, which will change the associated WC.
One example of this is performing primary exhaust system exchange of the radiological Continuous Air Monitor (CAM) filter. This work may be performed during standard operating conditions on the non-operating train (WC-2) or the operating train (WC-3). Additionally, this work may be performed during non-standard operating conditions (WC-4).
Co-located work is controlled through the controls applied for an individual activity.
If a work activity includes a system breach (regardless of application of an engineering control), that work activity must establish a temporary Exclusion Zone (EZ) for the system breach.
The temporary EZ boundary will either be controlled by the work crew (standing boundary) when the conditions specified in TFC-ESHQ-IH-C-48 Section 4.5 are met, or it will be posted with a physical barrier or signage. The boundary denotes the need for additional controls [i.e., Industrial Hygiene Technician (IHT) direct reading instrument (DRI) monitoring (WC-2/WC-3) and respiratory protection (WC-3)] to be in that area [(similar to establishing Airborne Radioactivity Areas (ARAs)].
The size of a boundary established depends on the size of the breach, size of the work area, and duration of the work. This will be determined by the IH during work planning for a specific evolution.
If a work activity has the potential to affect the entire farm, then that work activity will specify the requirement for a farm-wide temporary EZ. Under those conditions, all work entering the farm would be categorized as WC-4.
Per TFC-ESHQ-IH-C-48 Attachment B, the work scope examples provided above are usually:
WC-2 with the primary exhauster in operation and negative ventilation verified with direct reading instrument (DRI) (actively ventilated farms)
OR
WC-3 if an exhauster is not available (passively ventilated farms) or unable to maintain negative ventilation (actively ventilated farms).
The WC determination for specific work evolutions will be made by the responsible Industrial Hygienist during the work planning process/exposure assessment process.
Waste Disturbing Activity
TFC-ESHQ-IH-C-48 Definition:
NOTE: Although the Tank Vapor Waste Disturbing Activity definition does not materially differ from the intended use of the definition of “waste-disturbing activity” in the Hanford Challenge/Local 598/Parties Vapors Settlement Agreement, it does not replace it. All work activities will be evaluated for their potential to change the concentration of tank headspace gases and vapors. Both definitions provide the appropriate level of context for their respective intended audiences and provide the same concern for evaluation: some activities may change the concentration of the tank headspace gases and vapors. The definition provided in [TOC-IH-59014,] TOC-IH-58435 Appendix F, and TFC-ESHQ-IH-C-48 was modified from “waste-disturbing activity” to “Tank Vapor Waste Disturbing Activity” to further clarify this point.
Tank Vapor Waste Disturbing Activity: An activity that disturbs the tank waste resulting in the potential increase in headspace Tank Vapor concentrations.
Tank Vapor waste disturbing activities include:
Mixing of the waste (e.g., waste transfers, tank recirculation, [air lift circulator (ALC)] operation)
Waste processing (e.g., Evaporator Campaign, [Tank Side Cesium Removal (TSCR)])
Chemical processes (e.g., caustic additions, water additions)
In-tank preparations (e.g., water lancing)
No. Unlike mixing of waste and waste processing, not all chemical processes result in the potential to increase headspace Tank Vapor concentrations. However, depending on volume, a chemical process may be categorized as a Tank Vapor Waste Disturbing Activity. Therefore, they were included as examples.
This is consistent with the Settlement Agreement definition of “waste-disturbing activity”:
A “waste-disturbing activity” does not include, for example, … chemical/water additions involving amounts that do not cause a material increase in the concentrations of the tank head space gases and vapors.
No. A waste disturbing activity on its own does not change the assigned WC for a work activity.
The WCs are categories based on the Tank Farm operating configuration and the work activity’s relationship to a Tank Vapor containing system.
Determining Tank Vapor Intrusiveness is determining the potential exposure to Tank Vapors.
Non-Tank Vapor Intrusive = Low potential for Tank Vapor exposure
Tank Vapor Intrusive = Potential Tank Vapor exposure
NOTE: If exhauster concentrations exceed the High Alarm or High High Alarm set points, additional actions will be taken to reduce concentrations per ARP-T-041-00002. Refer to Event Response FAQs for more details.
Waste disturbing activities change the Tank Vapor concentrations but does not change the potential for Tank Vapors to be encountered during planned work configurations.
Sampling & Monitoring
Ammonia is the most common Tank Vapor Chemical of Potential Concern (COPC)/Chemical of Concern (COC) and is found in all tanks.
There is a moderate to very high inventory of ammonia everywhere that is tank waste.
Rapid and sustained ammonia release during waste disturbing activities (observed increase within minutes and present throughout the waste disturbing activity).
Mature and robust monitoring technology available.
Monitoring for ammonia provides early indication of changing conditions within a Tank Farm. To enhance the safety of Hanford Tank Farm workers, the Industrial Hygiene Department has established a Response Limit (RL) for use with Personal Ammonia Monitors (PAMs). The RL is set at 6 ppm ammonia and is a conservative and timely indicator of potentially changing conditions in Tank Farm gas/vapor conditions, at which prudent and protective investigative measures may be taken.
Stack monitoring (VMDS/VMDS Alternate) is one part of a multilayered monitoring system. Continuous air monitoring comes from multiple layers:
VMDS/VMDS Alternate direct reading instrument (DRI) monitoring [Tank Vapor Work Category (WC) 1, WC-2, WC-3).
Personal Ammonia Monitors (PAMs) for indication of changing conditions (WC-1 & WC-2).
Industrial Hygiene Technician (IHT) DRI Monitoring – Administrative Go/No-Go (WC-2, WC-3, WC-4).
No single monitoring system stands alone.
Yes. To request IHT DRI monitoring (courtesy monitoring), reach out to Field Work (FWS)/Operations Engineer (OE)/Person-in-Charge (PIC) assigned to the job or to your Field Industrial Hygienist (IH).
PAMs are utilized during work activities where Tank Vapor exposure is not anticipated [Tank Vapor Work Category (WC) 1 & WC-2]. The PAM provides an indication of changing conditions within the Tank Farm (e.g., fugitive emission points, exhauster plume to ground interaction).
NOTE: Tank Farm entry and work activities that do not breach a Tank Vapor containing system are categorized as WC-1.
Personal ammonia monitoring, or equivalent as directed by Industrial Hygienist, is required for Tank Farm entry under standard operating configuration.
Users should remove their PAM and provide them to a designated worker or place them in a designated place (e.g., table), taking care to note which device is theirs (e.g., tape with name).
NOTE: If tape is utilized to denote a user’s device, ensure the sensor is not blocked.
Upon the completion of the WC-3 activity, workers should re-attach the PAM to the outer layer of clothing, between the waste and the neck, in the open air and the sensor uncovered.
PAMs are not prohibited during WC-3 or WC-4 activities; however, they are not required and should not be worn during Tank Vapor intrusive activities. The purpose of the PAM is to provide an indication of changing conditions where Tank Vapor exposure is not anticipated.
NOTE: Each WC has a corresponding Tank Vapor Control Set established based on the potential for exposure to Tank Vapors. Refer to Tank Vapor Control Strategy FAQs for additional information on Tank Vapor Control Sets.
During WC-3 and WC-4 activities, Tank Vapors are anticipated as there is a known (WC-3) or potential (WC-4) open/direct path to Tank Vapors. As such, a PAM Response Limit (RL) alarm (6 ppm) or Action Limit (AL) alarm (12 ppm) is anticipated. While anticipated, if a worker wears a PAM during WC-3 or WC-4 work activities, they are still required to follow TFC-ESHQ-IH-C-78 Section 4.5 response actions:
- Check the ammonia levels of all PAM for the work crew
- Place work in a safe configuration
- Notify adjacent workers to avoid the area
- Exit the affected area (RL alarm) or the Tank Farm (AL alarm)
- Immediately notify the Shift Manager and follow their directions.
Upon notification, the Central Shift Manager (CSM) will determine if TF-AOP-015 exceptions or entry criteria are met. Having one response pathway for workers (safe configuration → exit area/farm → notify CSM) reduces potential human performance improvement (HPI) errors and ensures the Central Shift Manager determines whether the RL/AL alarm meets the TF-AOP-015 entry criteria.
As Tank Vapors are anticipated for WC-3 and WC-4 activities, continuous IHT DRI monitoring is required. The IHTs will monitor exposure source (e.g., breather outlet) (WC-3) or work area for indication of fugitive emission sources (WC-4). Additionally, they will monitor the worker breathing zone as necessary to ensure exposure does not exceed the maximum use concentration of the respiratory protection equipment.
Refer to Event Response FAQs for additional information on responding to PAM RL/AL alarms.
Bump Testing is a function test in which the PAM’s installed sensor is briefly exposed to (or “bumped” by) calibration gas in concentrations that are greater than the sensor’s low alarm setpoint. This validates gas detection and alarm functionality at prescribed setpoints.
Calibration involves exposing the PAM’s installed sensor to set concentrations of calibration gas (certified ammonia reference standard). Based on the sensor’s response, the PAM will be adjusted as necessary.
Following manufacturer’s recommendation, the PAM is bump tested weekly.
The PAMs undergo monthly calibration, ensuring their accuracy and reliability in routine operations. Additionally, the Ventis Team conducts inspections whenever a PAM operates outside predefined parameters or is flagged for segregation from the checkout stations for quality control testing.
During the checkout process, if the monitor alarms and indicates “Bump Overdue” or “Cal Overdue”, the PAM is to be returned to the issuing station, placed in the red bin, and the IH Ventis Pro Station Point-of-Contact (POC) is to be contacted.
If the PAM gives an abnormal audio or visual indication, the PAM is to be returned to the issuing station, placed in the red bin, and the IH Ventis Pro Station POC is to be contacted. Additionally, the Site Form A-6008-738 is to be completed.
PAM Contact Information, Site Form drop box (Alarms, Issues, & Concerns), and red bin.
For RL (6 ppm) or AL (12 ppm) alarms, immediately notify the Shift Manager and follow directions from the Shift Office.
If TF-AOP-015 is not entered, follow the abnormal audio or visual indication return process.
If TF-AOP-015 is entered, the alarming PAM(s) should be promptly returned to the Central Shift Office (CSO). The data will be downloaded and utilized to determine response actions.
Odor/Vapor Response Card Site Form (for location of alarm) and Site Form A-6008-738 are to be completed. Refer to Event Response FAQs for additional information on responding to PAM RL/AL alarms.
Whenever a PAM is flagged by our automated alerts and determined to need quality control (QC) testing, or if it triggered a TF-AOP-15 event, the Industrial Hygiene (IH) Equipment Subject Matter Expert (SME)/Program Owner conducts a thorough inspection.
This process involves checking for/assessing:
Physical damage
Assessing the health status of the sensors
Reviewing the instrument’s calibration and bump history
If the device has triggered an alarm, the inspection attempts to replicate the alarm using known field conditions to determine if the PAM is exhibiting any unusual or anomalous behavior.
As part of the investigation for TF-AOP-015 response, this information is captured in an Industrial Hygiene Equipment Investigation. Additionally, the equipment investigation will capture information from the event, functionality, precursory data, and a device analysis from the IH Equipment SME.
Yes. The Industrial Hygiene (IH) Data & Technology Management group has established an automated notification protocol when PAM instruments are outside pre-determined parameters. These alerts enable the prompt identification and removal of the affected instrument.
Prior to its return to service, the PAM must pass a comprehensive quality assurance (QA)/quality control (QC) evaluation.
Additionally, an analytics dashboard is used to evaluate PAM instrument integrity and operational performance, including sensor diagnostic status.
Per the manufacturer, an indicator of a sensor’s remaining life is the span reserve value. This value declines over the sensor’s life and is updated with each calibration. If span reserve value drops below 50%, the sensor will no longer pass calibration and is due for replacement.
In addition to the span reserve value, if the sensor begins to show abnormal behavior and its warranty period of two years has expired, it will be returned to the manufacturer for further evaluation and/or replacement.
No. PAMs are utilized as an indication of potentially changing conditions. While data collected from PAMs are not tied to a worker’s exposure record, workers may view the data from the devices they have worn through the Internal Data Access and Visualization (IDAV) Personal PAM Dashboard.
The Personal PAM Dashboard, accessible to all personnel via https://tankvapors.com, provides users with a detailed interface displaying their PAM device utilization over a continuous 3-month timeframe. The dashboard records daily instrument assignments and logs the maximum exposure reading recorded for each device.
Areas highlighted in green indicate areas where PAM data was recorded with readings below the RL (6 ppm). Areas with PAM data at or above the RL are highlighted in red. To adjust the dates, use the sliding bar.
NOTE: If blank, no PAM data has been recorded within the past 3 months.
Industrial Hygiene utilizes personal sampling to collect exposure record data. An air sampling device is placed in the worker’s breathing zone. Samples are sent off-site for analysis. Once results are returned, reviewed by the Industrial Hygienist, and the survey is completed, they are automatically reported to the individual through the Employee Notification of Personal Sampling Results (Notification Letter).
Yes. To request a personal sample set, reach out to your Field Industrial Hygienist (IH) or Industrial Hygiene Technician (IHT) assigned to the job.
There are two ways to receive personal sampling results from a job when the sample set was worn by another worker.
Representative Worker (Record) –
To be added as a Representative Worker on the Record copy of personal sampling results, reach out to your Field Industrial Hygienist (IH) or Industrial Hygiene Technician (IHT) assigned to the job. Your name/Hanford Identification (HID) number will be added to the Site Wide Industrial Hygiene Database (SWIHD) survey as a Representative. Once results are returned, reviewed by the IH, and the survey is completed, the Representative employee(s) automatically receives an Employee Notification of Personal Representative Sampling Results (Notification Letter).
If the request is made after the Personal Sampling evolution, ensure to include the dates and locations where the sampling occurred in the request to assist in identifying the correct record.
Results for Information (non-Record) –
Reach out to your Field IH with the request for information. If the request is made after the Personal Sampling evolution, ensure to include the dates and locations where the sampling occurred in the request to assist in identifying the correct record.
There is not a set number of workers an IHT can monitor. It will depend on the purpose of the monitoring [i.e., Personal Ammonia Monitor (PAM) equivalent monitoring, work activity monitoring].
Work Activity Monitoring:
No limit for number of workers. Monitoring requirements are specified based on the activity requirements.
PAM Equivalent Monitoring:
The number of IHTs required will depend on the anticipated work area size during activities requiring PAM equivalent monitoring [e.g., small work crew staying in close proximity while traversing to work location (IHTs ≥ 1), work crew spread out at multiple locations (IHTs ≥ 2)].
The responsible Industrial Hygienist (IH) will provide directions to IHT(s) for PAM equivalent monitoring.
Yes. PAMs are required unless an Industrial Hygienist (IH) directs PAM equivalent monitoring for a specific activity.
Emission Points/Boundaries
Field walk downs, rounds/routines, and preventative maintenance packages assist in the identification/prevention of fugitive emissions. That said, the Tank Vapor control strategy is a “trust but verify” system. Separate from work packages, the Industrial Hygiene Department conducts in-farm emissions source surveillance (IFESS). The IFESS routine proactively looks for fugitive emissions utilizing direct reading instrument (DRI) monitoring.
Industrial Hygiene works with Engineering to compile the list of potential Tank Vapor emission sources. Surveillances are performed in each Tank Farm at points randomly selected from the list of potential emission sources. If a new fugitive emission source is discovered, the Industrial Hygienist (IH) will immediately notify the Central Shift Manager (CSM). The fugitive emission source will be controlled as a Temporary Exclusion Zone (EZ) until it is mitigated.
Additionally, when Tank Vapor exposure is not anticipated for a work activity (non-Tank Vapor intrusive), workers are required to have a Personal Ammonia Monitor (PAM), or equivalent as directed by IH, as in indication of changing conditions, including fugitive emissions.
Permanent Exclusion Zone (EZs) are established around permanent EPs. When that area around the EP (the permanent EZ) is accessible without special equipment (e.g., scaffolding, aerial lift), then the EZ will be posted with a physical barrier and signage.
When permanent EZs are inaccessible without special equipment [e.g., 5 ft. from the outlet of the 241-AP Ventilation Tank Primary (VTP) A or B train exhaust stack], they are not required to be posted with a physical barrier or signage.
Temporary EZs are established around temporary EPs. If the EP is created for the work scope, and the associated temporary EZ is attended with continual control and Industrial Hygiene Technician (IHT) direct reading instrument (DRI) monitoring, the EZ is not required to be posted. The work crew can act as a standing temporary EZ boundary.
If the area has not been returned to its normal configuration, then when the temporary EZ is unattended, it will be posted with physical barrier and signage.
The administrative boundary signage for an exclusion zone is provided in Attachment A of TFC-ESHQ-IH-C-48. The applicable color requirements for a “WARNING” label have been incorporated into the exclusion zone signage. No additional Tank Vapor hazard-specific safety color requirements apply unless other hazard conditions are present that require supplemental safety signage.
When required to be posted with a physical barrier and signage in accordance with TFC-ESHQ-IH-C-48, the exclusion zone boundary should be established in accordance with the applicable sign, barrier, and posting requirements in TFC-ESHQ-S-STD-18. Under TFC-ESHQ-S-STD-18, boundaries must be clearly marked with signs and barriers that are strategically placed, legible, conspicuous, and visible from all directions of approach so personnel are warned in time to avoid inadvertent entry. Where lighting is inadequate, postings must be illuminated or retro-reflectorized.
If multiple hazard postings are required at the same location, they should be grouped together approximately one foot apart. Signs hung from rope, chain, or barricade tape should be maintained at a height of approximately 24 to 40 inches. Outdoor boundary signs should generally be spaced about 40 feet apart, unless a permanent fence at least 6 feet high exists, in which case posting is only required at access points.
TFC-ESHQ-S-STD-18 also requires that temporary barriers such as stanchions or fencing be stabilized to prevent displacement, that signs and barriers be removed or covered when the hazard no longer exists, and that signs placed on gates or doors remain visible when those access points are opened. If a boundary is posted with DANGER signs but is not constructed with red rope or red chain, red danger tape must be strung along the boundary to identify the hazardous area.
When an emission point (EP) is created for a work scope, the area will be controlled or posted as an Exclusion Zone (EZ). During work planning, the Industrial Hygienist (IH) will determine the measures necessary for a specific evolution. The size of the breach, size of the work area, and duration of the work are all factors. If there is a large work crew or a large area, it may be easier to control the EZ utilizing physical barriers and signs.
Prior to beginning a WC-3 work activity, work in that area is normally categorized as WC-1 or WC-3.
When the work area contains a permanent EP (starts as WC-3):
Accessible without special equipment- the EP is administratively controlled via a physical boundary and posting.
Inaccessible without special equipment- the EP is adequately controlled as it cannot be unintentionally accessed.
When the work creates a breach (starts as WC-1) and an engineering control cannot be applied (e.g., positive side of ventilation):
The work area is adequately controlled at the beginning as there is not normally an EP.
The system breach is then controlled via the work scope as necessary for the evolution with a minimum of IHT direct reading instrument (DRI) monitoring (administrative control) and respiratory protection equipment (RPE) (personal protective equipment).
Refer to TFC-ESHQ-IH-C-48 Section 4.5 for more details on this process.
The main administrative control for Tank Vapors during WC 2-4 activities is IHT DRI monitoring. Monitoring is utilized to verify the effectiveness of an engineering control (WC-2) and to ensure worker exposures do not exceed the maximum use concentration (MUC) of the RPE (WC-3 & 4).
The use of physical barriers and signs is required when a temporary EP is unattended. When attended, physical barriers and signs may be necessary in addition to monitoring to control the work area. This is similar to other Industrial Hygiene hazards (e.g., noise).
Tank Vapor Hazard-Based Respiratory Protection
Respiratory protection is required when there is a known or potential open/direct path to Tank Vapors without a validated engineering control. As there is a potential for Tank Vapors to be in the workspace, these activities are considered Tank Vapor Intrusive and are categorized as either Tank Vapor Work Category 3 (WC-3) or WC-4.
Additionally, respiratory protection may be required based on radiological hazards [i.e., Airborne Radioactivity Area (ARA)] and/or other industrial hygiene hazards (e.g., asbestos).
No. The EZ designation on its own does not automatically require respiratory protection.
There are two types of EZs, permanent and temporary.
Permanent EZs: Established around permanent emission points (EPs). Work categorized as Tank Vapor Work Category (WC) 3 or WC-4.
Temporary EZs: Established around temporary EPs. Work categorized as WC-2, WC-3, or WC-4.
The default minimum respiratory protection equipment (RPE) requirements are based on the potential for Tank Vapors to be in the workspace (i.e., WCs).
WC-1 & WC-2: No RPE required
WC-3 & WC-4: Full-Face Air Purifying Respirator (FFAPR) with Farm appropriate chemical cartridges
The default minimum RPE requirements are established for a broad range of work activities. These requirements may be upgraded or downgraded for individual/specific work activities through additional evaluation/Industrial Hygiene Task Specific Exposure Assessment(s).
There may be circumstances where donning and doffing respiratory protection within the farm is appropriate. However, those situations are associated with specific work activities and evaluated in advance. The evaluation is formally incorporated into the work planning process.
Contact your Radiological Control Supervisor/Planner/Engineer for additional information.
Yes. Workers can request voluntary use of respiratory protection equipment (RPE) when none is required or voluntary upgrade to RPE when respiratory protection is required, if the use does not pose a greater hazard (e.g., ergonomic).
Approved voluntary use/upgrade RPE is provided on the Respiratory Protection Form (RPF).
Voluntary use/upgrade is only allowed for employees who are medically qualified, trained, and fit tested for the RPE requested.
Workers can request to voluntary use respiratory, including ½ Face APR, during work that does not require the use of respiratory protection [e.g., Tank Vapor Work Category (WC) 1 or WC-2 work activities].
Additionally, PAPR use may be authorized case-by-case for heavy, extended-duration tasks, or documented medical restrictions. Approval must come from the COO, ESH&Q Manager, or IH Manager and be communicated to issue station supervision.
If there is not a hazard-based Respiratory Protection Form (RPF) for a work activity, workers can utilize the C48 RPFs, if the respiratory protection equipment (RPE) use does not pose a greater hazard. The respiratory protection prescribed in the C48 RPFs is based on Tank Vapors and is independent of other industrial hygiene hazards and radiological hazards.
Voluntary upgrade to a PAPR will depend on the hazards associated with the work, and the associated minimum respiratory protection requirements.
If respiratory protection is required for Tank Vapors (WC-3 or WC-4), then workers will not be able to voluntarily upgrade to a PAPR at this time. Currently approved PAPR RPE does not have a National Institute of Occupational Safety and Health (NIOSH) certified cartridge for ammonia and volatile organic compounds (VOCs).
If respiratory protection is not required for Tank Vapors (WC-1 or WC-2), then Industrial Hygiene and Radiological Control will determine the approved upgrade options based on the hazards. Approved upgrade options will be listed on the associated hazard-based RPF. The same PAPR use conditions will apply to voluntary upgrades within the Tank Farms.
There is not a distance requirement based on an individual wearing a mask (worker may be transversing, voluntary use).
There is a requirement for how close a worker can be to a Tank Vapor system breach that requires respiratory protection. However, it is not a fixed distance as it depends on the work being performed. During the planning evolution for a work scope, the Industrial Hygienist (IH) will determine the Exclusion Zone (EZ) boundary distance to be established during work.
An EZ must be large enough to encompass the area around the area that has the potential to exceed 50% of the Occupational Exposure Limit (OEL). The initial boundary should have a minimum 5-foot radius. The EZ boundary is to be identified using a physical barrier and signage, unless controlled as outlined in TFC-ESHQ-IH-C-48 Section 4.5 (e.g., by continuous monitoring).
Event Response
When responding to odors/personal ammonia monitor concentration alarm events, we enter TF-AOP-015, “Response to Personal Ammonia Monitor Alarm” or follow TFC-OPS-OPER-C-67, “Response to Stronger than Normal Odors”.
TF-AOP-015 is entered when there is a PAM Response Limit (RL) alarm (6 ppm) or PAM Action Limit (AL) alarm (12 ppm), unless one of specified situations listed in TF-AOP-015 is met.
We follow TFC-OPS-OPER-C-67 for stronger than normal odors encountered in the 200 East Area, 200 West Area, and 600 Areas controlled by H2C when the entry conditions for TF-AOP-015 have not been met.
Stronger than Normal Odor Determination includes:
The Central Shift Manager (CSM) will determine if the reported odor and odor strength are known or expected for the area or co-located activity. As needed, the CSM will contact Industrial Hygiene (IH) to provide input for substantiation of the determination.
If the odor and odor strength is confirmed to be known or expected for the area or co-located activity, the CSM will notify the reporting personnel, document in the CSM log, and discontinue response per TFC-OPS-OPER-C-67.
While it is currently uncommon for a C-67 response to occur inside Tank Farm boundaries, we follow TFC-OPS-OPER-C-67 for stronger than normal odors inside and outside of Tank Farm boundaries.
When these unexpected conditions are discovered, the response actions are to ensure that one of the following is met before work is allowed to continue:
The work area(s) are safe from hazardous chemical vapors
OR
Additional controls are put into place for the hazard identified.
Yes. If a PAM has an RL/AL alarm while not worn by the worker [e.g., Tank Vapor Work Category (WC) 3 activity, egressing from the farm], they are still required to follow TFC-ESHQ-IH-C-78 Section 4.5 response actions:
- Check the ammonia levels of all PAM for the work crew
- Place work in a safe configuration
- Notify adjacent workers to avoid the area
- Exit the affected area (RL alarm) or the Tank Farm (AL alarm)
- Immediately notify the Shift Manager and follow their directions.
The Central Shift Manager will determine if TF-AOP-015 entry criteria has been met.
The data from the alarming PAM is downloaded. The peak concentration is verified to ensure personnel have the appropriate respiratory protection for response actions.
If the exhauster shuts down, we will follow our current process for TF-AOP-021, “Response to Tank Farm Ventilation Upset”. This abnormal operating procedure directs immediate actions for the Central Shift Manager (CSM) to take. Actions include stopping waste disturbing activities and all work within the affected farm not associated with response to the event. Personnel inside of the affected farm must exit the farm, and the farm will be posted as an Exclusion Zone (EZ).
When active ventilation shuts down, the tank headspace concentrations will begin to increase; however, it is not instant. For some tanks, it may only take hours (20 – 600 hours) for the headspace concentrations to reach a steady-state. For other tanks, it may take years for the headspace concentrations to reach a steady-state.
Unplanned events, such as an exhauster shut down or meteorological conditions (e.g., capping inversion), are administratively controlled with a Personal Ammonia Monitor (PAM). Under standard operating conditions (e.g., exhauster running in an actively ventilated farm), all personnel entering the farm are required to wear a PAM, or equivalent as directed by an Industrial Hygienist (IH), per TFC-ESHQ-IH-C-48, “Managing Tank Chemical Vapors”. The PAM has an established Response Limit (RL), set at 6 ppm ammonia and is a conservative and timely indicator of potentially changing conditions in Tank Farm gas/vapor conditions. If a RL Alarm or Action Limit (AL) Alarm (12 ppm) is reached, we will respond following our current process for TF-AOP-015, “Response to Personal Ammonia Monitor Alarm”.
The alarm/action set points are based on a linear extrapolation of the QRA model prediction; conservatively established at the ammonia stack concentration that could result in various ammonia concentrations at an unspecified ground receptor (WRPS-1904672.1).
The High Alarm and High High Alarm set points may be established at a lower concentration than modeled.
High Alarm → ammonia concentration of 2.5 ppm at an unspecified ground receptor
High High Alarm → ammonia concentration of 5 ppm at an unspecified ground receptor
241-AP Farm Stack Concentration for Ammonia at Various Ground Concentrations (RPP-RPT-61679)
VMDS – Ammonia Concentration High:
IF the alarm is on an exhaust stack associated with active single-shell tank (SST) Retrieval, the Central Shift Manager (CSM) will request the Retrieval Operations Engineer (OE) modify retrieval techniques to minimize ammonia generation.
VMDS – Ammonia Concentration High High:
IF alarm is on an exhaust stack associated with a double-shell tank (DST) waste transfer or SST Retrieval, the CSM will request Waste Transfer OE or Retrieval OE shutdown waste transfer or SST retrieval.
TF-AOP-005, “Response to Unexpected Flammable Gas Concentration, Waste Level, or Waste Tank Temperature Change” addresses abnormal conditions relating to Tank Farm waste storage tanks and Tank Side Cesium Removal (TSCR) spent ion exchange columns (IXCs).
As part of the immediate actions for unexpected temperature increase, if a tank bump or over-pressurization occurs, the Abnormal Operating Procedure (AOP) directs the Central Shift Manager (CSM) to contact Safety and Health (Industrial Hygiene) to determine the appropriate respiratory protection requirements. A tank bump or over-pressurization could indicate a steam release event, a scenario likely to affect Tank Vapor headspace concentrations.
There are no formal response plans or records generated by this AOP. However, Industrial Hygiene will determine the appropriate Respiratory Protection Form (RPF) after assessing the hazard based on the abnormal conditions [e.g., classifying response actions as Tank Vapor Work Category (WC) 4 due to the non-standard operating condition within the Tank/Farm].
TF-AOP-011, “Response to Chemical and/or Radiological Events” provides guidelines for personnel safety when unexpected chemical or radiological hazards are discovered in the 200 East Area, 200 West Area, and 600 Areas controlled by H2C.
It mandates notification of relevant personnel to review Emergency Action Levels, conduct pre-job briefings, and consider critical topics including respiratory protection, Industrial Hygiene Sample Plan (IHSP), boundary establishment, and other follow-up actions as necessary. If follow on actions go beyond access restrictions, then a Response Plan is required.
The Response Plan includes a description of the event, response steps, personal protective equipment (PPE), IHSP, and Radiological Work Permit (RWP) to perform the follow-on actions. The Shift Manager determines the required signatures based on the nature and scope of the response. The Industrial Hygiene Professional’s involvement ensures the appropriate Industrial Hygiene controls (including Tank Vapor controls when applicable) are incorporated for the planned response.
TF-AOP-020, “Response for Placing Personnel and Equipment in a Safe Condition” encompasses responses to various operational events and unforeseen hazards not covered under other Abnormal Operating Procedures (AOPs).
Notification and involvement of the On-Call Industrial Hygiene (IH) professional is required to develop comprehensive response plans. As with TF-AOP-011, the IH Professional’s involvement ensures the appropriate Industrial Hygiene controls (including Tank Vapor controls when applicable) are incorporated for the planned response.