Skip to Main Page ContentSkip to SearchSkip to Site Map NavigationSkip to Footer Links

        - Home

        - FAQ
        - Glossary
        - Facility Locator
        - What's New
        - Site Help
        - Index A-Z
        - Contact Us
        - Email Updates
        -    Listen to page

Report a Safety Concern

      - Nuclear Reactors  - Power Reactors
- Research & Test Reactors
- Operating Reactors
- Operator Licensing
- New Reactors
- Operator Licensing for New Reactors
- Research Activities
- Nuclear Reactor Quick Links
 
      - Nuclear Materials  - Special Nuclear Material
- Source Material
- Byproduct Material
- Med, Ind, & Academic Uses
- Radium
- Uranium Recovery
- Fuel Cycle Facilities
- Materials Transportation
- Research Activities
- Nuclear Materials Quick Links
 
      - Radioactive Waste  - Decommissioning of Nuclear Facilities
- Low-Level Waste
- Waste Incidental to Reprocessing
- High-Level Waste
- Uranium Mill Tailings
- Low-Level Waste Disposal
- High-Level Waste Disposal
- Storage of Spent Nuclear Fuel
- Transportation of Spent Nuclear Fuel
- Research Activities
- Radioactive Waste Quick Links
 
      - Nuclear Security  - Domestic Safeguards
- Information Security
- Radioactive Material Security
- Required Reporting for Clearance Holders
- Insider Threat Program for Licensees
- Criminal History & Firearms Checks
- Contact Us
 
      - Public Meetings & Involvement  - The NRC Approach to Open Government
- About Meetings Open to the Public
- Conferences & Symposia
- Documents for Comment
- NRC Rules and Petitions
- Facilitating Stakeholder Involvement
- NRC Information Quality Guidelines
- Subscribe to E-mail Updates
- Commission Schedule
- Adjudications (Hearings)
- Public Meeting Schedule
- Adjudicatory Submissions
 
      - NRC Library  - Basic References
- Document Collections
- ADAMS Public Documents
- Public Document Room
- LSN Library
- FOIA & Privacy Act
- Records Management
- Training Courses
- FAQ Index
- Get Copies of Documents
- Withholding of Sensitive Information
- Photos & Video
- Electronic Hearing Docket
 
      - About NRC  - The Commission
- Organization & Functions
- Governing Legislation
- Plans, Budget, & Performance
- Locations
- History
- Values
- Direction-Setting & Policymaking
- Research Activities
- Radiation Protection
- Fire Protection
- Safety Culture
- How We Regulate
- Emergency Preparedness & Response
- Public Affairs
- Congressional Affairs
- Enforcement
- International Programs
- State & Tribal Programs
- Alternative Dispute Resolution Programs
- Privacy Program
- Civil Rights
- Contact Us
- Career Opportunities
- Contracting Opportunities
- Small Businesses
- Grant Opportunities
 

Print

HomeNRC LibraryDocument CollectionsGeneric CommunicationsInformation Notices1980

# Information Notice No.80-29 - Broken Studs on Terry Turbine Steam Inlet Flange

```
                                                           SSINS No.:  6835 
                                                           Accession No.:  
                                                           8006190028      

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                          WASHINGTON, D.C. 20555  
                                     
                              August 7, 1980  

                                           Information Notice No. 80-29 

BROKEN STUDS ON TERRY TURBINE STEAM INLET FLANGE 

When removing the governor and stop valve on the Unit 1 steam driven 
emergency feedwater pump at Arkansas Nuclear One for repair of a steam leak 
at the steam inlet flange Arkansas Power and Light discovered that five of 
the eight studs securing the flange were broken. 

The cause of the stud failure is unknown at this time. Metallurgical 
evaluation of the failed bolting will be performed to identify the mode of 
failure. 

The failed studs are 3/4 in. diameter by 3-1/2 in. long and are thought to 
be of ASTA-193 grade B7 steel. The turbine flange bolting is generally 
covered with insulation and not visible for inspection. From the information
available, the bolting has not been removed or inspected since installation 
seven to eight years ago. 

The steam driven emergency feedwater pump turbine at ANO-1 is a type G 
turbine manufactured by the Terry Steam Turbine Company of Hartford, 
Connecticut. The turbine is rated at 680 BHP and 3560 RPM. The turbine 
operates at a reduced steam pressure of 270 psig and temperature of 
400F and has previously experienced overspeed trips and vibrations 
which may have been caused by slugs of water from the piping. 

Licensees are encouraged to carefully examine insulation in the flange to 
turbine casing region for evidence of leakage and consider inspection of the
turbine steam inlet flange bolting. Further, during surveillance testing, 
care should be taken to observe if abnormal vibration or other transients 
occur which could promote loss of bolting integrity. 

This Information Notice is provided as an early notification of a possibly 
significant matter that is still under review by the NRC staff. It is 
expected that recipients will review the information for possible 
applicability to their facility. No specific action or response is requested
at this time. If you have any questions regarding this matter, please 
contact the Director of the appropriate NRC Regional Office.
```

*Page Last Reviewed/Updated Friday, May 22, 2015*

#### Home

            - News Releases
            - Event Reports
            - ADAMS
            - Open Gov
            - Digital Government
            - The Student Corner
            - Photos & Video
            - For Developers

#### About Us

            - Strategic Plan
            - Budget & Performance
            - Agency Financial Report
            - License Fees
            - History of the NRC
            - Career Opportunities
            - NRC Ethics
            - Agency Status
            - Contact Us

#### Popular Documents

            - Info Digest
            - Fact Sheets & Brochures
            - Forms
            - Electronic Submittals Application
            - Adjudicatory Submissions
            - NRC Reports – NUREG
            - NRC Regulations – 10-CFR
            - Inspection Reports
            - Plain Writing
            - Enforcement Actions
            - RULEMAKING

#### Stay Connected

            - Blog
            - Facebook
            - Twitter
            - YouTube
            - Flickr
            - GovDelivery
            - RSS

Regulations.govUSA.govRecoveryFOIANo Fear EEOInspector General ProgramSite MapAccessibilityPrivacy PolicySite DisclaimerFor Employees