u n c l a s s i f i e d changes to epa radiological stack monitoring requirements, and ramifications...

U N C L A S S I F I E D


Changes to EPA Radiological Stack Monitoring Requirements, and

Ramifications on LANL Operations

David Fuehne, CHP

March 22, 2005 – AMUG Meeting

LA-UR-05-1903



Discussion Areas

• EPA standard for radiological stack monitoring

• 2003 changes to standard

• Maintenance & inspection requirements– LANL impact

• Design criteria for new stacks– LANL impact

• Conclusions

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EPA Standard for Radiological Stack Monitoring

• 40 CFR 61, Subpart H – DOE facilities

• 10 millirem per year – Entire laboratory is one facility– Receptor is residence, school, business

• Stack monitoring required if potential emissions exceed 0.1 mrem per year– Normal operations – No credit for pollution controls (HEPA, scrubbers, etc.)

• LANL – Meteorology & Air Quality group, Environmental Stewardship division

• 28 monitored stacks

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Changes to the Standard in 2003

• Incorporate ANSI/HPS N13.1-1999– Revision to 1969 standard– Maintenance & inspection criteria– Design criteria for samplers and emission stacks

• Existing emissions sources– Grandfathered design– Maintenance & inspection criteria apply

• New or Modified Stacks– All design criteria apply– M&I criteria

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Maintenance & Inspection

Criteria



Maintenance & Inspection Requirements

• Many minor items – calibrated electronics, clear rotameters, etc.

• Stack sample system inspection program – Annual inspections– Nozzles, probes, sample lines– Proper alignment– Free from damage– Free from deposition

• Clean the systems if deposition is observed – When? No guidance provided

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M&I Requirements:LANL Implementation Plan

• Flexible borescope into stack lines

• Focus on nozzle openings, probes, bends in sample lines

• Record images – photos & video

• 2003: Six systems with visible deposition– Two were easy to clean– Two were difficult to clean– Two were impossible

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M&I Requirements – LANL Implementation:Easy to clean

Accelerator stack – discrete point of deposition

• Caulking / sealant – HVAC maintenance?

• Immediately removed during inspection

• Small amount of rad material (sub-nanocurie Co-60) on cleaning material, include in annual source term

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M&I Requirements – LANL Implementation:Easy to clean

Rad liquid waste treatment facility

• Wet environment – condensed vapors

• Straightforward cleaning - remove, wipe down, replace

• Small downtime on sampler

• No detectable rad material in cleaning solution, cloths

• Completed within 60 days of discovery

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M&I Requirements – LANL Implementation:Difficult to clean

• Research facility – two stacks

• Straightforward problem, complex solution

• Nuclear facility issues– Safety review process– Perchlorate concerns – bomb gear – Stack fan shutdown, coordinate with users

• Oil mist on surfaces – HVAC maintenance

• No detectable activity on surfaces, cleaning materials

• Completed ~18 months after discovery

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M&I Requirements – LANL Implementation:Impossible to Clean

• Nuclear facility, two stacks– Original stack samplers, ~ 30 years installed– Visible scale on external surfaces

• Old design – 1969 samplers– Low transport efficiency <20%– Three 90-degree bends

• Operation issues – restricted access, no backup samplers

• Decision – Replace, not clean– Four sample rakes on each stack – independent– Roof level – simplify access– EPA agrees to plan– Deadline : Dec 2005 – 24 months after initial inspection

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Effects of Deposition on Emissions Data?

• Already assume some particulate losses will occur

• Assumed rate-of-loss based on large diameter particles

• Emissions calculations correct for these assumptions

• Double-count by including rad material from inspections in annual source term– Most cleaning shows NDA– One stack with sub-nanocurie levels

• Result – no negative impact on program; conservatism is built-in

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Changes to M&I Program - Audit

• Visually examine external surfaces as well as internal surfaces – inspect nozzle conditions

• Record imagery each year

• Formalize process with procedure, annual performance summary– Currently – IWDs, checklists

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Design Criteria



Design Criteria for New & Modified StacksSample probe performance

• Recommend single-point shrouded probe

• Nozzle transmission ratio 80-130%

• Particle transmission to collection media >50%

• 10 micron particles used for analysis

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Design Criteria for New & Modified Stacks:Sample location

• Well-mixed, uniform flow– Justifies single point sampler

• Flow angle > 20 degrees

• Velocity profile COV < 20%

• Aerosol concentration COV < 20%– Use 10 micron particles to test

• Iterative process – pick location & test – Failure – test new location– Swiss-cheese stack

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Design Criteria for New & Modified StacksComplicating factors

When do these criteria apply?

• New source, including new construction in existing buildings

• Modification of existing source– Modification must cause increase in off-site dose >0.1 millirem/yr– Certain activities are NOT modifications

• Review new activities for sampler system design adequacy

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Design Criteria for New & Modified StacksComplicating factors

LANL stacks – Seven systems meeting design criteria

• Locate new ops in these buildings

More reviews required, more manpower requirements

• EPA notification timeline

• Monitoring yes/no/what

• System design adequacy

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LANL Example

Waste Repackaging Facility



Design Criteria, LANL Example:Waste Repackaging Facility

• Original plan – new construction– Easy to meet requirements– Tall stack, smooth transitions, “clean” system to test

• New plan – retrofit existing system– Poor fan-to-stack transitions– Aerosol injection points– Accessing sampling points – scaffolding

• Problems generating 10 um aerosol in quantity

• Stack tests unsuccessful

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• Move sampler to new location – glove box exhaust

• Long straight runs

• Lower air volume to dilute aerosol

• Concern – facility as a whole is not monitored, just primary glove box operation

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Lessons Learned

• Time Line– Entire process – six months to get approved location

• Capability to perform these tests in the future– Aerosol R&D team dissolved years ago– MAQ stack engineering team “streamlined”– Collaboration among 3+ groups required – priorities?– Rely on outside vendors – clearances, training, schedule

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LANL Example

TRU Waste Vitrification



Design Criteria, LANL Example:TRU Waste Vitrification

• New process at LANL = new source of emissions

• Off-site dose potential over 0.1 millirem per year

• Retrofit existing stack? Cannot meet design criteria

• Cannot change buildings – material concerns

• Solution – brand new stack(s)– Not same as sampler upgrade discussed earlier

• Capital funding required; multiple years delay

• Operations cannot commence until upgrade complete

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Conclusions



Conclusions

New maintenance & inspection criteria

• Routine inspection requirements are good improvement

• Cleaning activities can impact facility operations

• “Gray area” on time window for completion of cleaning activities

• Compliance issues could arise if cleaning operations delayed

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Conclusions, continued

Design criteria

• Additional workload for new process reviews

• Retrofitting existing systems can be problematic

• Testing capability at LANL may not be available

• Iterative testing can be frustrating

• Can result in significant delays for planned operations

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Thanks for your time!

• Questions or comments?

David Fuehne

LANL ENV-MAQ

505-665-3850

[email protected]

http://www.airquality.lanl.gov

external web site

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u n c l a s s i f i e d changes to epa radiological stack monitoring requirements, and ramifications...

Documents

s s i f i e d changes

s s i f i e d epa standard

mi criteria

stack lines

business stack monitoring

stacks original stack

inspection small

clean research facility