You are here

Light Water Reactor Sustainability Technical Documents

September 30, 2011
Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Initial Assessment of Thermal Annealing Needs and Challenges

The most life-limiting structural component in light-water reactors (LWR) is the reactor pressure vessel (RPV) because replacement of the RPV is not considered a viable option at this time. LWR licenses are now being extended from 40y to 60y by the U.S. Nuclear Regulatory Commission (NRC) with intentions to extend licenses to 80y and beyond. The RPV materials exhibit varying degrees of sensitivity to irradiation-induced embrittlement (decreased toughness) , as shown in Fig. 1.1, and extending operation from 40y to 80y implies a doubling of the neutron exposure for the RPV.

September 30, 2011
Develop baseline computational model for proactive welding stress management to suppress helium induced cracking during weld repair

There are over 100 nuclear power plants operating in the U.S., which generate approximately 20% of the nation’s electricity. These plants range from 15 to 40 years old. Extending the service lives of the current fleet of nuclear power plants beyond 60 years is imperative to allow for the environmentally-sustainable energy infrastructure being developed and matured.

September 30, 2011
Report on Assessment of Environmentally-­Assisted Fatigue for LWR Extended Service Conditions

This report provides an update on the assessment of environmentally-assisted fatigue for light water reactor (LWR) extended service conditions. The report is a deliverable in FY11 under the work package for LWRS under the Advanced Reactor Concepts.

September 30, 2011
Implementation Plan and Initial Development of Nuclear Concrete Materials Database for Light Water Reactor Sustainability Program

The FY10 activities for development of a nuclear concrete materials database to support the Light Water Reactor Sustainability Program are summarized. The database will be designed and constructed using the ORNL materials database infrastructure established for the Gen IV Materials Handbook to achieve cost reduction and development efficiency.

August 30, 2011
Advanced Instrumentation, Information, and Control System Technologies: Nondestructive Examination Technologies – FY11 Report

Licensees of commercial nuclear power plants in the United States are expected to submit license renewal applications for the period of operation of 60 to 80 years which has also been referred to as long term operation (LTO). The greatest challenges to LTO are associated with degradation of passive components as active components are routinely maintained and repaired or placed through maintenance programs.

July 30, 2011
Physics-Based Stress Corrosion Cracking Component Reliability Model cast in an R7-Compatible Cumulative Damage Framework

The Risk-Informed Safety Margin Characterization (RISMC) pathway is a set of activities defined under the U.S. Department of Energy Light Water Reactor Sustainability Program. The overarching objective of RISMC is to support plant life-extension decision-making by providing a state-of-knowledge characterization of safety margins in key systems, structures, and components (SSCs).

June 30, 2011
Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Assessment of High Value Surveillance Materials

The reactor pressure vessel (RPV) in a light-water reactor (LWR) represents the first line of defense against a release of radiation in case of an accident. Thus, regulations that govern the operation of commercial nuclear power plants require conservative margins of fracture toughness, both during normal operation and under accident scenarios. In the unirradiated condition, the RPV has sufficient fracture toughness such that failure is implausible under any postulated condition, including pressurized thermal shock (PTS) in pressurized water reactors (PWR).

January 30, 2011
Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Milestone Report on Materials and Machining of Specimens for the ATR-2 Experiment

The reactor pressure vessel (RPV) in a light-water reactor (LWR) represents the first line of defense against a release of radiation in case of an accident. Thus, regulations, which govern the operation of commercial nuclear power plants, require conservative margins of fracture toughness, both during normal operation and under accident scenarios. In the unirradiated condition, the RPV has sufficient fracture toughness such that failure is implausible under any postulated condition, including pressurized thermal shock (PTS) in pressurized water reactors (PWR).

December 31, 2010
Cooling Water Issues and Opportunities at U.S. Nuclear Power Plants, December 2010

Energy and water are both essential to sustainable development and economic productivity. Ample supplies of water are essential to energy production, and water management is dependent on ample supplies of energy for water treatment and transportation. The critical nexus between energy and water has been recognized in a variety of recent studies, but the policy and regulatory machinery that this nexus depends on is not keeping up with the growing challenges.

December 30, 2010
Assessment of Initial Test Conditions for Experiments to Assess Irradiation Assisted Stress Corrosion Cracking Mechanisms

Irradiation-assisted stress corrosion cracking is a key materials degradation issue in today’s nuclear power reactor fleet and affects critical structural components within the reactor core. The effects of increased exposure to irradiation, stress, and/or coolant can substantially increase susceptibility to stress-corrosion cracking of austenitic steels in high-temperature water environments. Despite 30 years of experience, the underlying mechanisms of Irradiation Assisted Stress Corrosion Cracking (IASCC) are unknown.

July 1, 2010
July 2010, Status and Outlook for Nuclear Energy In the United States

The U.S. nuclear power industry continues to make pro- gress toward the construction of new nuclear power plants in the United States. Currently, 13 license applica- tions are under active review by the Nuclear Regulatory Commission (NRC) for up to 22 new reactors. The De- partment of Energy has awarded conditional commit- ments for loan guarantees to the partners in the Vogtle project and is negotiating terms for loan guarantees with several new nuclear projects.

April 1, 2008
Materials Degradation in Light Water Reactors: Life After 60

Nuclear reactors present a very harsh environment for components service. Components within a reactor core must tolerate high temperature water, stress, vibration, and an intense neutron field. Degradation of materials in this environment can lead to reduced performance, and in some cases, sudden failure. A recent EPRI-led study interviewed 47 US nuclear utility executives to gauge perspectives on long-term operation of nuclear reactors. Nearly 90% indicated that extensions of reactor lifetimes to beyond 60 years were likely.

June 8, 2007
Running Dry at the Power Plant

Securing sufficient supplies of fresh water for societal, industrial, and agricultural uses while protecting the natural environment is becoming increasingly difficult in many parts of the United States. Climate variability and change may exacerbate the situation through hotter weather and disrupted precipitation patterns that promote regional droughts. Achieving long- term water sustainability will require balancing competing needs effectively, managing water resources more holistically, and developing innovative approaches to water use and conserva- tion.