Purpose of Fort Calhoun N.P.P. Site Characterization
Energy Solutions LLC., (EnergySolutions) is in the process of D&D for Fort Calhoun N.P.P. and adjoining facilities. These facilities are to be dismantled, and the demolition waste is sized into manageable pieces for handling and disposal or left in place for basement waste backfilling. The facilities undergoing D&D were typically chemically and radiologically contaminated or activated. To facilitate the upfront characterization work, EnergySolutions required tools capable of rapidly profiling the bulk building materials to 1.5" to 6" surface depth rapidly and representatively.
Profiling the concretes of the nuclear site areas and radiological buildings to depth included the following desired capabilities and design features of the equipment: (a) powered by a facility electric supply coupled to 100-foot power cables, (b) removal of approximately 807 concrete samples and six metal samples from 178 locations with some locations from the inner metal liner from the containment shell, (c) remove 2.0 inch, 4 x 0.5 inch and 4.0 inch, 2 x 2 inch from predetermined sampling points and 1.5 inches. 3 x 0.5-inch incremental depths of potentially contaminated concrete from predetermined locations, each location screened for rebar(d) collection of all concrete and metal as particulate from sampling operations into specialized filter units and (e) produce representative samples in a powdered form for optimal counting by a portable gamma spectrometer in the onsite lab. The site-wide successful sampling campaign took 20 workdays to complete, accessing highly constrained containment contaminated areas and high radiation areas swiftly and profiled surgically enhancing ALARA principles and eliminating volumetric concrete historical unknowns.
TruPro® methodology for the radiological characterization of contaminated area, concrete slabs, walls of nuclear power plant containment units and of nuclear process facilities as required by NUREG-1700, Standard Review Plan for Evaluating Power Reactor License Termination Plans as real and credible defensible data matters.
NMNTI’s TruPro® Patented Technology, concrete / metal sampling and profiling tools, provide a superior smarter solution and approach to concrete or bulk material sampling and analysis to the traditional methods of concrete or metal sampling using a wet or dry coring machine or robots.
Required by NUREG-1700, Standard Review Plan for Evaluating Power Reactor License Termination Plans
The primary objectives of radiological characterization are to:
- Provide a basis for survey unit classifications
- Provide a basis for identification and distribution of ROC
- Provide a basis for the lateral and vertical extent of contamination in soils, concrete, and systems (concentrate on areas present at end state)
- Evaluate the variability of radioactivity
- Evaluate neutron activation of concrete
- Provide sufficient data to determine waste streams
- Provide sufficient data to guide remediation planning/selection of technology
With our nuclear facility characterization services site uncertainties and surprises are negated upfront
We provide reliable, affordable sampling and characterization services for our nuclear clients. We offer ourextensively developed and successfully implemented insitu portable tools for the assessment and radiochemical analysis of redundant nuclear buildings and preconditioned process radwastes to help program decommissioning strategy design at reduced radiological risk, cost and project time.
TruPro® Patented Technology Process Steps
Concrete sampling using TruPro® technology
Lighter weight – no bolting required – magnetic available.
Typically uses hollow ½” drill bit
More narrow bit is more likely to miss re-bar/tendons
Does not need water to cool. System is air-cooled
Vac system collects dust into baggies in increments
Durations for Sampling via TruPro®
25 minutes per sample location
12 sample locations per day
17 work days to collect 185 sample locations
Plus 5 days for analysis time
Work Crews for Sampling via TruPro®
1 NMNTI Drill Operator at location
1 NMNTI Support Individual (sample Chain of Custody)
1 Radiation Protection Technician
ALARA Considerations Implemented by Utilizing TruPro® Patented Concrete Profiling Technology
Under Vessel Area 5 sample locations Average Dose Rate: 300 mR/hour
TruPro® Concrete Profiling
12 minutes/location x 5 locations = 1 hour in area
0.3 rem/individual x 2 = 0.6 rem total
An RWP is required for this work
Under Vessel Area 5 sample locations
Average Dose Rate: 300 mR/hour
CORING
2 hours/core x 5 cores = 10 hours in area
3 rem/individual x 3 = 9 rem total
Work would be denied (wait until vessel/source term removal)
NRC Upfront Characterization Criteria Met
NRC has been critical of the number of samples taken at previous projects during initial characterization surveys. Use of TruPro® technology allows for far more samples to be collected in a shorter period of time. Because of the enclosed vacuum system there is a less chance of cross-contamination during collection and handling (material contained in filter). This provides better Quality Controls.
Product Highlights
- Advantages of sampling via TruPro versus core boring
- Rate of sampling (17 working days v 55 working days)
- No secondary waste or airborne (vacuum) and no water used (air-cooled)
- Smaller holes (1/2” v 3”) means less potential for fracturing concrete or encountering re-bar or tendons
- Reduced cross contamination of sample (no water, no slicing)
- Increased safety due to less exposure to physical hazards (less weight and no requirement for bolting drill to surfaces)
- Reduced dose due to less time in radiation fields
- Reduced project cost and better defensible actionable data