Headquarters Daily report SEPTEMBER 22, 1994 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X *************************************************************************** PRIORITY ATTENTION REQUIRED MORNING REPORT - HEADQUARTERS SEP. 22, 1994 MR Number: H-94-0087 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS BRANCH/EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT OFFICE OF NUCLEAR REACTOR REGULATION Subject: N/A NRC Information Notice 94-69, "Potential Inadequacies in the Prediction of Torque Requirements for and Torque Output of Motor-Operated Butterfly Valves," to be issued September 28, 1994. The NRC is issuing this information notice to alert addressees to potential inadequacies in the prediction of torque requirements for and torque output of motor-operated butterfly valves. Technical contacts: Thomas G. Scarbrough, NRR (301) 504-2794 William T. Orders, RII (803) 383-4571 Perry C. Hopkins, RII (803) 831-2963 Christine Lipa, RIII (319) 851-5111 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV SEPTEMBER 22, 1994 Licensee/Facility: Notification: Gulf States Utilities Co. MR Number: 4-94-0107 River Bend 1 Date: 09/22/94 St Francisville,Louisiana Resident Inspector Dockets: 50-458 BWR/GE-6 Subject: REFUELING MAST DROPPED ONTO UPPER CORE SUPPORT PLATE Reportable Event Number: N/A Discussion: On September 21, 1994, at 4:30 p.m. (CDT), the licensee dropped the refueling bridge mast 6 feet onto the top of the upper core plate during testing of the mast's lower interlock switch. The refueling bridge was being tested to support fuel sipping and indentification of a leaking fuel assembly. The licensee determined that no damage to the mast or fuel assemblies occurred. The licensee has declared the refueling bridge inoperable and has initiated an event review team to determine the root cause of the failure. The refueling bridge mast is lowered into the refueling cavity and reactor vessel by two 5/16" cables, which are wrapped onto a cable drum by cable sheaves. The cables are attached to the drum by capture balls on the cable ends, which are fitted into slots on the drum. The distance between the top of the refueling cavity and the top of the fuel is 53' 10". The licensee's preliminary investigation has determined that, when the vendor (General Electric) replaced the refueling bridge and the fuel handling bridge cables during Refueling Outage 5, an incorrect length of cable was installed on the refueling bridge mast. The refueling bridge mast cables and the fuel handling bridge cables are 70 ft and 55 ft long, respectively. The licensee has determined that the refueling bridge and fuel handling cables in the warehouse have the same part number; therefore, the wrong length of cable was supplied when a replacement part was requested during the outage. As a result of having shorter cables on the mast, a smaller amount of cable was left on the drum when the mast was lowered into the refueling cavity. The smaller diameter of the remaining cables reduced the amount of tension on the wrapped cables and allowed the capture balls to come out of the drum slots, the cables to unroll, and the mast to fall. The cables did not completely fall into the cavity because they both became snagged on the sheave box on the refueling bridge. The licensee has located replacement 70-ft cables at another utility and is measuring all similar cables onsite. Regional Action: Additional followup by the resident inspectors. Contact: C. A. VanDenburgh (817)860-8161