MPR's Nuclear Experience

Background
The U.S. Nuclear Regulatory Commission (NRC) significantly changed its rules for license renewal when it issued the Maintenance Rule (10CFR50.65) in July 1991, and the License Renewal Rule (10CFR50.54) in May 1995. These rules are more objective and realistic than the former requirements for license renewal, and this action by the NRC has encouraged utilities to reconsider the possibility of license renewal for their nuclear plants. Additional factors favoring license renewal include:

• Need for generator capacity--Although there is a national surplus of electric generation at this time, the combination of utility and IPP construction is not keeping up with demand, and generation is expected to tighten up in 5-10 years.

• Competition--Existing nuclear plants can be cost repetitive in a market driven economy because, in many cases, the marginal production costs (fuel and O&M) are considerably lower for nuclear plants than for existing coal-fired plants or even new high-efficiency gas turbine combined cycle plants.

License Renewal, therefore, is economically attractive for nuclear plants that can maintain high capacity factors over the long term.

Qualifications and Expertise
MPR Associates, Inc. has a history of over 30 years of providing engineering services to the commercial nuclear power industry. This work has included numerous material condition evaluations for nuclear and fossil fueled generating stations, as well as generic aging assessment work for the industry: MPR authored EPRI Report TR100844, Nuclear Power Plant Common Aging Terminology, November 1992.

MPR has extensive experience in solving challenging technical problems that threatened the useful life of major components, for example:

• Reactor Vessel Nozzle Penetrations--Development, analysis, and testing of roll repairs for reactor coolant system nozzles, and for control rod drive system stub tubes

• Reactor Vessel Internals--BWR core shroud repair (patented), and PWR internal bolting failure evaluation

• Steam Generators--Assessment of tube remaining life, and development of insitu corrosion monitoring instrumentation for SG chemical cleaning (patented)

• Pressurizer--Metallurgical evaluation and development of repair of Alloy 600 stress corrosion cracking in heater sleeves

• Containment--Developed BWR drywell sandbed repair, and BWR torus corrosion assessments and recommended repairs

MPR recently completed an Aging Management Review Component Supports for a two-unit PWR, In performing this review,

MPR used a commodity approach, on the basis that component supports perform basically the same function regardless of the system with which they are associated. Treating component supports as commodities, as opposed to performing the aging management review for each individual component support within the scope of license renewal, resulted in a cost-effective approach for this portion of the plant's Integrated Plant Assessment for license renewal.

Another important cost-effective feature of the component support review was the use of existing programs, especially the recently-completed USI A-46 (seismic verification) program. MPR's knowledge of the scope of the A-46 program, which used the Seismic Qualification Utility Group (SQUG) earthquake experience-based methodology, allowed us to evaluate the program scope and provide the technical justification required to credit A-46 work as a key element in the aging management program for component supports.

License Renewal Services

MPR can help utilities to:

• Perform plant material condition reviews and assess the technical and economic justification for continued operation and license renewal.
• Solve challenging technical problems that could limit plant life, e.g., reactor core shroud cracking reactor internal bolting failures (PWR).
• Develop creative, cost-effective approaches to license renewal, e.g., commodity approach to component support aging management review.

Contact

For further information on License Renewal or other services provided by MPR Associates, contact: Caroline Schlaseman, PE or Will Grant

More MPR Nuclear Experience

• ALWR Development
• Configuration Management
• Design Bases Integration
• License Renewal Engr Svcs
• Main Coolant Pumps
• MPR BWR ECCS Suction Strainer Svcs
• MPR Qualifications Related to Restart & Startup Assessments for The Office of Nuclear Safety
• Soviet-Designed Nuclear Reactor Plants
• Valve Experience

The following pages provide insight on our experience in a few of MPR's nuclear D&D projects:

• Three Mile Island Unit 2 Reactor
  
• Technical Assistance for PUREX
  
• Technical Oversight at Fort St. Vrain
  
• Radioactive Waste Handling
  
• Spent Nuclear Fuel Handling Shipping and Storage
  
• Radiation Shielding Design
  
• Chernobyl
  
• Hanford Spent Nuclear Fuel Project