Specialized Services for Nuclear

Component Operation Simulation

LPI, Inc. can develop component operation simulation using combination of modeling, kinematics and analysis to simulate performance under operating scenarios. LPI's experience has encompassed various air operated valve and check valve behavior, simulation sequencing of spent nuclear fuel loading into casks, and construction load sequencing.

LPI, Inc. has capabilities to test component performance through data acquisition and digital capture.

Operability Assessments

Life expectancy of components is continually challenged with the aging of the nuclear fleet in the US. This often results in degraded conditions that require assessments to support continued plant operation. LPI's engineers have evaluated many such components, often with tight schedules necessary to support determinations. We can quickly mobilize experts to work independently or with plant teams to develop the technical basis in support of plant operability determinations.

Program Support Services

LPI, Inc. has been actively involved in many of the most significant programs in the nuclear industry in the last 20 years. These have included FAC programs, valve programs, service water system fluid transients, buried piping and gas intrusion analysis services.


Flow Accelerated Corrosion (FAC), can lead to wall thinning in pipes, valves heater shells and tanks in BWR, PWR and CANDU nuclear plants and within fossil power plant systems. FAC is the dissolution of the normally protective oxide layer on the inside surface of carbon and low alloy steel piping. The iron oxides that naturally form on the exposed surface of the pipe are removed by mass transfer to the de-oxygenated water flowing over the pipe inside surface.

Resulting failures of pressure components can lead to catastrophic events, with significant down time for repairs. LPI, Inc. personnel have been involved in FAC assessments of piping systems since the early identification of this problem in US nuclear plants. Our experience extends to all nuclear power plant types, and the review of a significant number of fossil stations.

We understand how plants operate and work closely with plant personnel, soliciting input and valuable insights from system engineers, operations, maintenance and NDE personnel.

Valve Programs

Our valve analysis experience extends over many years, with active involvement since the beginning of the GL89-10 motor operated valve program in US nuclear plants. Our engineers have performed assessments using our structural engineering capabilities to develop weak link assessments, our mechanical engineering abilities to perform set-up and capability evaluations, and our fluid engineers predict flow, drag, blow-down and check valve performance. LPI's capabilities and service encompass:

  • Valve failure analysis
  • Valve and actuator mechanical analysis
  • Qualification of valve designs to meet structural and performance specifications
  • Analysis to predict valve performance for motor-operated, air-operated, and hydraulically operated gate, butterfly, globe and check valves
  • Valve/actuator design modifications
  • Valve analysis per ASME code requirements

Buried Piping Programs

Degradation of buried piping is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. Although degradation mechanisms are often slow, they are progressive. As plants reach 30 and 40 years of operation, increased instances of inadvertent radiological release from these underground systems is expected, based on the industry experience to date. This has been an issue for license renewal, and plants have generally been required to commit to opportunistic inspections of these underground systems.

Many nuclear plant systems contain one or more lines that are buried. These systems may include safety and non-safety service water, circulating water, fire protection, diesel fuel oil, spent-fuel pool cooling water, miscellaneous radioactive lines, off-gas and yard drains. Many buried lines are coated or tape-wrapped with materials such as concrete, coal tar, asphalt-based materials, or epoxy. Although many of these lines were cathodically protected when plants were constructed, in many cases the cathodic protection system may not have been maintained or used consistently. The result is accelerated external degradation at locations where the coating has failed. Additionally, certain systems can be subject to internal corrosion as a result of microbiological influenced corrosion (MIC), and other degradation mechanisms.

LPI, Inc. can offer our clients the expertise of our staff with extensive experience in corrosion control, program development, and fitness-for-service assessments. Our experience encompasses program development services, including risk ranking, NDE planning, direct examination, and data evaluation, based on our comprehensive Fitness-for-Service expertise.

Our experience includes:

  • Fleet support services for a leading US operator
  • Model and database development
  • Risk ranking of fleet SSCs (including radiological piping, tanks and sumps)
  • Drawing development for ease of location of plant SSCs and monitoring wells

Plant SSC Aging Programs

Go to System and Component Aging

Specialized Design

LPI, Inc. can provide specialized design services to support plant modifications, associated with areas of our engineering specialization.

LPI's engineers have successfully designed structural hardening concepts associated with vital and security assets subjected to blast loading. Work has included structural design of security command centers, blast and ballistic enclosure support structures and towers and barrier designs.

Our engineers have designed complete radioactive waste and clean-up systems for spent fuel pools, together with designs of necessary infrastructure to support dry cask campaigns, including fuel pool bridge, cask loading platforms and concrete loading pads.

System and Component Aging

LPI, Inc. has performed extensive system and component aging and life cycle management evaluations. These have ranged from procedures for inspection or system walk-downs to prediction of failure probability to the end of plant operation.

Life Cycle Management

LPI, Inc. personnel have worked extensively both on programs for Life Cycle Management and individual component life cycle assessments. Evaluations of specific equipment have included buried piping and infrastructure, rotating equipment, cables, large NSSS equipment, and others. Programmatically, LPI, Inc. personnel have developed methods to systematically assess degraded conditions. This has included training of personnel and implementation of programs.

This topic is particularly pertinent as operating plants extend their licenses and look at maintaining high operating reliability and containing costs. This places a premium on the quality of decision-making that assures all expenditures are focused on maintaining safety and reliability.

Concrete Aging Assessment

As infrastructure ages assessing degradation of major structures is important to determine life expectancy and prediction of required ongoing maintenance requirements.

Much of the Nation's major structures, including buildings, bridges, and power facilities utilize concrete. Aging effects of this material are often not visible from the outside, until significant corrosion or degradation has taken place. LPI, Inc. has provided services to owners over many years to assist in the characterization of concrete structures to assess condition.

Our services have included:

  • Long-term monitoring, and crack assessment
  • Core sample analysis, compression testing, chemical analysis and petrographic examination
  • Pre and Post tensioned concrete aging assessments
  • Cable assessment
  • Rebar corrosion prediction
  • Permeability assessments

Our evaluations have included:

  • Building Infrastructure
    • Stadiums and sports arenas
    • Sky-scrapers
    • Fire damage
  • Bridges
  • Nuclear Power Facilities
    • Containment assessment
    • Spent fuel pool degradation assessments for boric acid corrosion
    • Refuel Cavity Assessment
    • Off-gas stack assessment

Buried Piping Assessments

Go to Buried Piping

Spent Fuel Pool Evaluation

A number of plants have experienced leakage from fuel pools and transfer canals, leading to tritium contamination. Such leaks are often very small and usually below the measurement threshold available to in-plant installed systems. LPI, Inc. personnel have designed test configurations and conducted long-term tests to quantify the leakage from pools down to small quantifiable amounts. LPI, Inc. personnel have also performed remote inspection and direct inspection of transfer canal liners to identify leakage areas and develop repair strategies. Long-term leakage from spent fuel pools often raise questions relative to effects on concrete and reinforcing bars as a result of boric acid corrosion. LPI, Inc. has performed a number of assessments to predict damage, including extraction of concrete samples deep into the spent fuel pool wall, and assessment of concrete performance from decommissioned nuclear plant spent fuel pool facilities.

Third Party Review

As nuclear plant owners are faced with complex challenges ranging to in-vessel component qualification, primary coolant loop assessments for power uprate and life extension or degradation from in-service corrosion mechanisms, the solution to such problems can be challenging and complex.

To assist plant owners, LPI, Inc. experts work alongside the owner to assist in technical assessment of NSSS evaluations, or act in an independent advisory role with third party review services.

Our projects have ranged from steam dryers in BWRs, vessel nozzle issues, steam generator tube degradation, RCP mechanical seal failure, and others.

For more information, please contact Paul Bruck by email at, or by phone at (978) 378-1180.