ML101810282 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, DC 20555-001 January 31, 2011 NRC INFORMATION NOTICE 2011-02: OPERATOR PERFORMANCE ISSUES INVOLVING REACTIVITY MANAGEMENT AT NUCLEAR POWER PLANTS
ADDRESSEES
All holders of operating licenses for nuclear power reactors under the provisions of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, "Domestic Licensing of Production and Utilization Facilities," except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reacto
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform addressees of events involving deficiencies with reactivity management planning and implementatio The NRC expects recipients to review the information for applicability to their facilities and to consider actions, as appropriate, to avoid similar problem Suggestions contained in this IN are not NRC requirements; therefore, no specific action or written response is require DESCRIPTION OF CIRCUMSTANCES Callaway Plant During a Callaway Plant shutdown in October 2003, the control room operators did not effectively control core reactivity during low-power operation The event began on the morning of October 20, 2003, when the Callaway Plant experienced an inverter failure on a safety-related bus that put the unit in a 24-hour technical specification action to restore the inverter or be in Mode 3 (hot standby) within the next 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> The next morning, because the inverter had not yet been restored, operators initiated a plant shutdown at approximately 10 percent per hou With the main turbine on line and with turbine bypass valves closed, operators attempted to stabilize the plant at approximately 8-percent powe Per procedure, operators opened the turbine drain valves, which increased main steam flow, reducing reactor coolant temperature and adding positive reactivit At the same time, negative reactivity was being inserted by xenon buildup, decreasing reactor powe The net effect was that reactor coolant temperature decreased by approximately 10 degrees Fahrenheit over a half-hour perio Operators did not withdraw control rods or dilute boron concentration to stabilize reactor power or reactor coolant temperatur As a result of the lowering reactor coolant temperature, pressurizer level lowered enough to cause letdown to isolat In addition, reactor coolant temperature decreased below the technical specification required minimum temperature while critical for several minute In response to the lowering reactor coolant temperature, the IN 2011-02
|
---|
|
list | - Information Notice 2011-01, Commercial Grade Dedication Issues Identified During NRC Inspections (15 February 2011, Topic: Commercial Grade Dedication)
- Information Notice 2011-02, Operator Performance Issues Involving Reactivity Management at Nuclear Power Plants (31 January 2011, Topic: Downpower)
- Information Notice 2011-03, Nonconsecutive Criticality Safety Analyses for Fuel Storage (16 February 2011, Topic: Nonconservative Technical Specifications)
- Information Notice 2011-03, Nonconsecutive Criticality Safety analyses for Fuel Storage (16 February 2011, Topic: Nonconservative Technical Specifications)
- Information Notice 2011-04, in: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors (23 February 2011, Topic: Boric Acid)
- Information Notice 2011-04, In: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors (23 February 2011, Topic: Boric Acid)
- Information Notice 2011-04, IN: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors (23 February 2011, Topic: Boric Acid)
- Information Notice 2011-05, Tohoku-Taiheiyou-Oki Earthquake Effects on Japanese Nuclear Power Plants (18 March 2011, Topic: Boric Acid, B.5.b Mitigating Strategies, Earthquake)
- Information Notice 2011-07, Specific License Required When Exporting To Embargoed Destinations Listed In 10 CFR 110.28 (14 April 2011, Topic: Moisture Density Gauge)
- Information Notice 2011-08, Tohoku-Taiheiyou-Oki Earthquake Effects on Japanese Nuclear Power Plants - for Fuel Cycle Facilities (31 March 2011, Topic: Boric Acid, Earthquake)
- Information Notice 2011-10, Thermal Issues Identified During Loading of Spent Fuel Storage Casks (2 May 2011, Topic: Fuel cladding)
- Information Notice 2011-11, Heat and Smoke Detector Requirements for 10 CFR Part 36 Irradiators (27 April 2011, Topic: Pandemic)
- Information Notice 2011-12, Reactor Trips Resulting from Water Intrusion Into Electrical Equipment (16 June 2011, Topic: Preliminary White Finding)
- Information Notice 2011-12, Reactor Trips Resulting from Water Intrusion into Electrical Equipment (16 June 2011, Topic: Preliminary White Finding)
- Information Notice 2011-13, OFFICIAL EXHIBIT - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13) (29 June 2011, Topic: Shutdown Margin)
- Information Notice 2011-13, Official Exhibit - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13) (29 June 2011, Topic: Shutdown Margin)
- Information Notice 2011-13, Official Exhibit - Nys000329-00-Bd01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (Nrc in 2011-13) (29 June 2011, Topic: Shutdown Margin)
- Information Notice 2011-14, Component Cooling Water System Gas Accumulation and Other Performance Issues (18 July 2011, Topic: Unanalyzed Condition, Preliminary White Finding)
- Information Notice 2011-15, Steel Containment Degradation and Associated License Renewal Aging Management Issues (1 August 2011, Topic: Coatings, Incorporated by reference, Aging Management, Moisture barrier)
- Information Notice 2011-17, Calculation Methodologies for Operability Determinations of Gas Voids in Nuclear Power Plant Piping (26 July 2011, Topic: Functionality Assessment)
- Information Notice 2011-19, Licensee Event Reports Containing Information Pertaining to Defects to Basic Components (26 September 2011)
- Information Notice 2011-20, NRC060 - NRC Information Notice 2011-20: Concrete Degradation by Alkali-Silica Reaction (Nov. 18, 2011) (24 July 2019, Topic: Aging Management)
- Information Notice 2011-21, Realistic Emergency Core Cooling System Evaluation Model Effects Resulting From Nuclear Fuel Thermal Conductivity Degradation (13 December 2011, Topic: Fuel cladding)
- Information Notice 2011-21, Realistic Emergency Core Cooling System Evaluation Model Effects Resulting from Nuclear Fuel Thermal Conductivity Degradation (13 December 2011, Topic: Fuel cladding)
- Information Notice 2011-22, Instrumentation & Control Module Failures, Incorrect Configurations and Settings (21 December 2011)
|
---|