Headquarters Daily report MAY 19, 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 MAY 19, 1994 MR Number: H-94-0050 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 91-81, Supp. 1, "Switchyard Problems That Contribute to Loss of Offsite Power," to be issued May 19, 1994. The NRC is issuing this supplement to Information Notice (IN) 91-81, "Switchyard Problems That Contribute To Loss Of Offsite Power," dated December 16, 1991, to alert addressees to a possible zener diode failure that could cause false operation in stuck breaker failure unit (SBFU) relays and certain (SA-1) generator differential relays. The SBFU and differential relays in question were manufactured by Westinghouse Electric Corporation (Westinghouse). Technical contact: Kamalakar R. Naidu, NRR (301) 504-2980 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I MAY 19, 1994 Licensee/Facility: Notification: Gpu Nuclear Corp. MR Number: 1-94-0058 Oyster Creek 1 Date: 05/19/94 Forked River,New Jersey SRI PC Dockets: 50-219 BWR/GE-2 Subject: WHITING CRANCE COUPLING DEFECT Reportable Event Number: N/A Discussion: During recent modifications to the turbine building crane (Whiting, 150 ton main hoist, 40 ton auxiliary hoist) the license identified a casting defect in the main hoist motor to gear box coupling. The coupling is two sections, the driver and the driven, the face section is (all numbers approximate) 10.5 inches in diameter with a thickness of 1.75 inches on the outer rim, the raised center portion (shaft collar) is an additional 1.5 inches thicker than the face portion and 6 inches in diameter with a shaft hole of 2.75 inches in diameter. The coupling is 'sand cast' to the approximate size and shape then machined to specifications specified on a drawing for a specific (by serial No.) crane. The coupling defect identified started at the machined edge where the collar joins the large diameter face section and penetrated through the collar into the keyway. There was no evidence of propagation of the defect and the crane had passed all previous load tests. The defect appears to be an original casting defect dating back to the 1960s. The coupling was replaced by a forged steel coupling machined by American Crane Co. As a result the licensee inspected the reactor building crane (Whiting, 100 ton main hoist, 5 ton auxiliary hoist) main hoist to gear box coupling (same approximate size as turbine building crane coupling). The licensee identified a defect in a location (machined edge where the shaft collar joins the face section) similar to the turbine building crane. The licensee examined the coupling using magnetic particle testing and identified defect propagation of about 2 inches on both sides of the defect. The licensee on discovery of the defect on the reactor building crane issued directions not to use the heater bay crane (Whiting) until its coupling could be inspected. They also ordered two new sets (4 sections) of motor to gear box couplings from Whiting Crane for the reactor building crane. Both sets of new couplings were rejected by the licensee due to minor and major surface pitting identified during receipt inspection. Whiting has agreed to machine new couplings for the reactor building crane and will perform radiography tests to ensure the couplings are acceptable. Information obtained by the licensee indicates that the main hoist to gear box coupling for each crane is uniquely identified by a drawing associated with the specific crane's serial No. The couplings identified with defects were all 'sand castings' that had been machined to size. The licensee is preparing to submit information to the nuclear network and a voluntary licensee event report. Regional Action: Resident Inspection Followup Contact: John Rogge (610)337-5146 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I MAY 19, 1994 Licensee/Facility: Notification: Northeast Utilities MR Number: 1-94-0059 Millstone 2 Date: 05/19/94 Waterford,Connecticut RI PC Dockets: 50-336 PWR/CE Subject: PLANT START-UP DELAYED Reportable Event Number: N/A Discussion: On May 18, 1994, Northeast Utilities management announced that Millstone Unit 2 would not be returned to operation as scheduled this week, pending a management evaluation of the staff's readiness to operate the facility. Unit 2 shutdown on April 23, 1994 for a short maintenance outage. Staff response to several off-normal conditions during this outage have raised concern that corrective actions implemented in 1993, as a result of Unit 2 performance deficiencies, were not achieving the expected results. Preliminarily, the licensee plans to identify weak staff areas and implement an augmented strategy for management oversight/mentoring. The licensee intends to implement its strategy within two weeks and return the unit to operation for about 60 days when a scheduled refuel outage will begin. The oversight/mentoring resources are expected to continue through the refuel outage and subsequent plant start-up. Regional Action: Millstone Assessment Panel Review Contact: Lawrence Doerflein (610)337-5378 Roberto De La Esprie (203)444-5404