David Perkins [email protected] Seabrook Station Biweekly Airborne Sampling.

David Perkins

[email protected]

Seabrook StationBiweekly Airborne Sampling

Objectives

•Improve system reliability

•Improve regulatory confidence

•Reduce out-of-service time

•Improve program efficiency and maintain a system of continuous sampling.

Bi-weekly Sample Feasibility

Ability to increase sample frequency

•Equipment reliability

•Ability to achieve sensitivity for short-lived isotopes

•Impact on charcoal efficiency

•Excess filter loading

•Eliminate missed samples

What We Found

•Remotely monitor equipment with telemetry and vacuum sensing transducer

•Maintain equipment with preventative maintenance

•Evaluation of I-131confirmed ability to achieve comparable sensitivity during 2-week collection period

•Charcoal efficiency testing for 2-week run time successful

•Effluent program informs REMP when I-131 release limits are exceeded for sample frequency adjustments

Automatic Remote Monitoring

Remote System Monitoring

•Reliability

•Capabilities

•Immediate problem notification

•Power outages

•Filter loading

•Equipment failure

•Cost effective

TelemetricT646 MicroRTU

• Off-the-shelf proven technology

• Six digital inputs, four analog inputs; six control outputs

• Automatically communicates pressure, flow and other sensing signals

• Capable of alert and alarm functions

• Operating parameters are remotely programmable and remotely selectable

• Low cost to buy and operate

How Telemetric Solution Works

Flow Diagram with Telemetry

Alarms/Response

Alert Probable Cause Shift Tech ActionLow pressure Torn filter, degraded tubing

or degraded pumpContact HPSupervisionEnter alert in HP log

High pressure Excessive filter loading Contact HPSupervisionEnter alert in HP log

A/C Power Loss GFI breaker tripLoss of power from supplysource.

Contact HPSupervisionEnter alert in HP log

A/C PowerRestored

A/C power restored totelemetry device and airsample pump.

None

Equipment Maintenance

Equipment Arrangement

Preventive maintenance

• Rebuild pumps – annually

• Calibrate gas meters – semi-annually

• Verify air flow – semi-annually or as needed

• Inspect equipment for degradation – bi-weekly

Equipment Upgrades

Filter Loading & Charcoal Efficiency

Filter Load Trend Plot

Rock Pile Trend

0

0.5

1

1.5

2

2.5

3

Date

Vac

Pres

sure

Series1

Filter change

Rock Pile1-Week & 2-Week

1-Week March 2004 2-Week June 2004

Filter Load Trend Plot

Plate Yard Trend

2.22.25

2.32.35

2.42.45

2.52.55

2.62.65

Date

Vac

Pre

ssur

e

Series1

Filter change

Plate Yard2-Week

June 2004

Charcoal Efficiency Testing

• Sample cartridges tested for 336 hours– 3 tests performed– 2 cfm flow rate– Test method, ASTM D-3803-98

• Results equal to or better than 99.30%

I-131and 2-Week Sample Cycle

I-131 Decay

1-week Vs. 2-week air sampling cycle

• Hypothetical models– Assuming chronic air concentrations

– MDA equal to or better than the 1-week cycle.

– Higher collection factor compensates for decay

– Modest air flow increase

Iodine Decay

1-week Vs. 2-week air sampling cycle

• Models show increased collection factors for flow rates

1-week flow rate 2-week flow rate Activity increaseRatio 2wk : 1wk

1.0 cfm 1.8 cfm 2.79 times 0.99

1.0 cfm 1.5 cfm 2.31 times 0.82

1.5 cfm 2.7 cfm 2.86 times 0.98

1.5 cfm 1.5 cfm 1.55 times 0.55

Administrative Controls

• REMP evaluates the need for increased sampling when:– ODCM monthly and instantaneous limits are exceeded– Failed fuel– Outages

How is 2-Week Sampling

working ?• Saved missed samples and out-of-service time

– Utility turned power supply off without notification

• Contacted utility and loss of power restored in 2-hours

• 150 hours of OOS time saved

– Equipment problem discovered

• Low pressure detected from tube connection leak

• 72 hours of OOS time saved

• System performs more reliably

• Filter loading is monitored more closely– Slightly increasing over 2-weeks, but NOT excessively

Questions?