Information Notice No. 86-05, Supplement 1:Main Steam Safety Valve Test Failures and Ring Setting Adjustments
SSINS No: 6835 IN 86-05, Supplement 1 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, DC 20555 October 16, 1986 Information Notice No. NO 86-05, SUPPLEMENT 1: MAIN STEAM SAFETY VALVE TEST FAILURES AND RING SETTING ADJUSTMENTS Addressees: All nuclear power reactor facilities holding an operating license or a construction permit Purpose: This notice is being provided as a supplement to Information Notice (IN) 86-05 to inform licensees of additional experience with ring setting adjustments of main steam safety valves (MSSVs) It is expected that recipients will review the information for applicability to their facilities and consider actions, if, appropriate, to preclude a similar problem from occurring at their facilities However, suggestions contained in this information notice do not constitute NRC requirements; therefore, no specific action or written response is required Description of Circumstances: Seabrook, 1985 (Synopsis) In the fall of 1984, Seabrook's MSSVs (manufactured by Crosby) were sent to Wyle Laboratories for testing The results of the tests showed that adequate disc travel was not attainable with the factory-set ring settings Following additional testing, the ring settings were adjusted from the factory settings to obtain the required disc travel Vogtle, 1986 On May 14, 1986, Georgia Power Company informed the NRC that 5 of the 20 Crosby MSSVs due to be installed on Vogtle 1 were tested to determine the appropriateness of their as-shipped ring settings (nozzle ring setting of +150 and guide ring setting of -45) The valve settings did not achieve specified relieving capacity The typical relieving flow was 75% of the specified value Subsequently all 20 of the valves were shipped to the Crosby high-flow test facility to be tested and adjusted as required to achieve their design relief capacity Final ring settings are summarized in Attachment 1 Note that these settings in many instances differ considerably from the as-shipped settings Unit 2 valves are due to be tested in the future 8610100107 IN 86-05, Supplement 1 October 16, 1986 Page 2 of 2 Millstone 3, 1986 On July 29, 1986 while inspecting the A-bank MSSVs, personnel found that the upper and lower adjusting rings were not set to the vendor's (Dresser) recommended settings After an investigation, it was determined that the vendor had not reset the rings following functional testing because of a procedural inadequacy Millstone 3 personnel reset all rings to the recommended settings (Licensee Event Report 50/423-86/043) Susquehanna 1 and 2 Pennsylvania Power and Light personnel recognized the 6R1O designation used by Seabrook to describe their valves (IN 86-05) as being the same as the Crosby safety/relief valves (SRVs) installed at Susquehanna Units 1 and 2; however, the designation 6R1O is not a model number, but the inlet, orifice, and outlet size of the valve These SRVs are not the same model as the Seabrook or Vogtle valves, but they do have adjusting rings which determine the capacity and blowdown of the valves Because of this, the information in IN 86-05 and this supplement may be applicable to boiling-water reactors No specific action or written response is required by this information notice If you have any questions about this matter, please contact the Regional Administrator of the appropriate regional office or this office Edward L Jordan Director Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement Technical Contact: Mary S Wegner, IE (301) 492-4511 Attachment: 1 Summary of Final Rings Settings for Vogtle 1 2 List of Recently Issued IE Information Notices
Page Last Reviewed/Updated Tuesday, March 09, 2021
Page Last Reviewed/Updated Tuesday, March 09, 2021