MTA-MA-016 - Revision history

Monica Hurley: Revision 0 Reviewed by Colton Smith

2026-03-26T17:28:09Z

Revision 0 Reviewed by Colton Smith

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 {{DISPLAYTITLE:Reduce Scheduling Cost, Dose, and Waste in Inspection of Steam Generator Tubing Using an Enhanced Bobbin Eddy Current Coil Inspection Technique - MTA-MA-016}}
 {{MTATemplate||
 | Date |12/15/2020
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 Steam Generator Management Program: Pressurized Water Reactor Steam Generator Examination Guidelines: Revision 8 (EPRI [https://www.epri.com/research/products/3002007572 3002007572])
-Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines: Revision 4 (EPRI [https://www.epri.com/research/products/3002007571 3002007571])
+Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines, Revision 5 (EPRI [https://www.epri.com/research/products/000000003002020909 3002020909])
-| Industry SME | EPRI – Bill Cullen
+| Industry SME | EPRI – SGMP
 Contact: NuclearPlantMod@epri.com
 | Previous Implementation | Please contact EPRI for implementation examples and contacts.
 | Implementation Enablers | N/A
 | Applicability | Applicable to nuclear plants with steam generators
 Applicable to all geographic regions
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 ==Risks==
 No unique risks beyond standard project risks associated with implementing changes at nuclear power plants.

Jacob Sommer: 1 revision imported

2026-03-05T01:37:55Z

1 revision imported

← Older revision	Revision as of 01:37, 5 March 2026
(No difference)

10.142.237.162 at 20:12, 3 March 2026

2026-03-03T20:12:47Z

New page

{{DISPLAYTITLE:Reduce Scheduling Cost, Dose, and Waste in Inspection of Steam Generator Tubing Using an Enhanced Bobbin Eddy Current Coil Inspection Technique - MTA-MA-016}}
{{MTATemplate||
| Date |12/15/2020
| Functional Area Where Benefits Will Be Realized | Maintenance
Engineering

Quality Control
| Reference Implementation Guidance |
2017 TIP Award Enhanced Steam Generator Tube Foreign Object Wear Detection Using the Bobbin Eddy Current Coil (ID: 10107950)

Steam Generator Management Program: Pressurized Water Reactor Steam Generator Examination Guidelines: Revision 8 (EPRI [https://www.epri.com/research/products/3002007572 3002007572])

Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines: Revision 4 (EPRI [https://www.epri.com/research/products/3002007571 3002007571])
| Industry SME | EPRI – Bill Cullen
Contact: NuclearPlantMod@epri.com
| Previous Implementation | Please contact EPRI for implementation examples and contacts.
| Implementation Enablers | N/A
| SWEEP Score |
* Cost – Level 3 – Implementation cost of the three frequency mix channel technique with the steam generator inspection compare software is less than $1 million. Depending on the plant’s current analysis software, the costs associated with outage inspection data preparation and quantification may already be included. If not, then data preparation and quantification costs are approximately $100,000 per unit per outage. Purchase of the compare software from the vendor costs approximately $50,000.
* Savings – Level 1 – Savings are less than $1 million per year. Savings are estimated to be between $200,000-500,000 per outage based on previous implementations. Savings are driven by the size of the steam generator and the tubing material.
* Payback – Level 2 – Payback period is greater than one year but less than five years (inclusive). Payback is driven by when the techniques are implemented relative to the next scheduled outage.
* Licensing – Level 3 – This methodology has already been implemented at nuclear power plants.
* Technology Readiness – Level 3 – The methodology is already in use at nuclear power plants and is ready for wide operational deployment.
* Implementation Proficiency – Level 3 – The implementation of the enhanced bobbin eddy current coil inspection methodologies does not require knowledge in implementing digital technologies.
| Applicability | Applicable to nuclear plants with steam generators
Applicable to all geographic regions
| Keywords | Steam generator inspection; eddy current; bobbin probe; supplemental probe; degradation detection
| Business Case Analysis Cross-Reference | N/A
}}

==Description==
Eddy current examination of steam generator tubing is performed to detect flaws such as corrosion, pitting, cracks, and erosion. A bobbin eddy current inspection probe made of conductive coils is excited with an electric current to produce an alternating magnetic field, inducing an electric current in nearby conductive materials (known as eddy currents). Defects on the surface or within the tubing material cause changes in the phase and amplitude of the eddy current. Typical methods of bobbin probe examination have difficulty detecting foreign object‑induced wear at geometric changes of tubing, specifically near the tubesheet transition region, requiring a supplemental probe to complete the inspection. Use of a supplemental probe in this transition region represents a significant portion of the inspection cost while foreign object wear at this location typically affects a very small number of tubes at any given inspection.

An enhanced bobbin current coil inspection technique uses mixing of high, mid, and low frequencies (“ALFS” mixes) to improve the bobbin coils’ detection capabilities for foreign object wear at the tubesheet transition region. The technique is qualified up to a specific three‑frequency mix noise level. This threshold is plant specific and is a function of the steam generator design and operating conditions. For tubes which exhibit three‑frequency noise exceeding this threshold, inspection is performed using a supplemental probe. Analysis of the three‑frequency mix channel technique data can be accomplished by manual analysis or by using computer‑based compare programs. This technique reduces the supplemental probe scope, in some applications by 90 % to 95 %, and, therefore, results in improved outage schedules, personnel safety, and overall outage costs.

==Benefits==
===Benefits Estimate===
Level 1 – Savings are less than $1 million per year. Savings are estimated to be between $200,000‑500,000 per outage based on previous implementations. Savings are driven by the size of the steam generator and the tubing material.

===Benefits Description===
* Reduction in personnel dose because fewer supplemental probe examinations are required (Palo Verde saw an 85% reduction in supplemental probe use and Braidwood saw a 66% reduction).
* Reduction in contaminated solid waste because fewer supplemental probe change‑outs are required.
* Improved outage scheduling by limiting the extent of supplemental probe inspections.
* Reduction in human error associated with changing analysis methods between the bobbin probe and supplemental probe.

==Costs and Schedule==
===Cost===
Level 3 – Implementation cost of the three‑frequency mix channel technique with the steam generator inspection compare software is less than $1 million. Depending on the plant’s current analysis software, the costs associated with outage inspection data preparation and quantification may already be included. If not, data preparation and quantification costs are approximately $100,000 per unit per outage. Purchase of the compare software from the vendor costs approximately $50,000 (see Previous Implementation for vendor options).

===Schedule===
Less than six months.

===Scope Context===
Per unit. Cost and schedule estimates are driven by outage inspection data preparation and implementation of the steam generator inspection compare software. The three‑frequency mix and additional noise/history reviews can be added to the existing frequency channels at minimal cost.

==Risks==
No unique risks beyond standard project risks associated with implementing changes at nuclear power plants.