![]() |
Search Options | |||
Index | Site Map | FAQ | Facility Info | Reading Rm | New | Help | Glossary | Contact Us | ![]() |
PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV MARCH 17, 1995 Licensee/Facility: Notification: Southern California Edison & San MR Number: 4-95-0035 Diego Gas & Electric Co. Date: 03/17/95 San Onofre 2 Telephone Call from Resident San Clemente,California Dockets: 50-361 PWR/CE Subject: IMPROPERLY SIZED LUGS IN SAFETY-RELATED SWITCHGEAR Reportable Event Number: N/A Discussion: On March 15, 1995, the licensee discovered that the wrong size lugs were connected to wires for incoming and outgoing DC control power to various Unit 2 safety-related circuit breakers. The affected circuit breakers were located in the Train B Class 1E 4.16 KV switchgear and in the Train B Class 1E 480 volt switchgear. The licensee made the discovery while the switchgear was deenergized during the Unit 2 current refueling outage. The lugs were color-coded yellow with three black stripes, which should have been 14/16-gauge, per the vendor catalogue. The lugs were actually 10/12-gauge and were installed on 14-gauge wire. Consequently, the lugs were too large for the application and could separate from the wire more easily than a properly sized lug. The lugs were manufactured by Amp Incorporated, of Harrisburg, PA, and the switchgear was provided by ITE Imperial, now owned by ABB/Combustion Engineering. The lugs are a part of the switchgear and have been in place since construction in the early 1980s. The licensee contacted Amp, Incorporated and the company is researching color coding requirements for lug size during the time in which the switchgear was provided. The licensee is evaluating the reportability of this occurrence under 10 CFR Part 21. The licensee plans to replace the improper lugs prior to declaring the switchgear operable. The licensee also plans to inspect the other Class 1E 4.16 KV and 480 Volt switchgear (Unit 2 Train A and both trains in Unit 3) at the next opportunity. The inspection requires removing wires from terminals and reading the inscribed lug size. The inspection cannot be accomplished with DC control power energized. The licensee's preliminary risk evaluation of having lugs too large was that the risk was small, as there was no evidence of separation of the wires from the lugs. The licensee found that most lugs were tightly connected to the wires. Previous work to replace DC circuit breakers had not identified any loose connections. In addition, a control room alarm will occur to indicate a problem with DC control power if a lug separated from a wire. San Onofre Unit 2 is currently in Mode 6 during a refueling outage, and Unit 3 is operating at full power. REGION IV MORNING REPORT PAGE 2 MARCH 17, 1995 MR Number: 4-95-0035 (cont.) Regional Action: The resident inspectors will monitor the licensee's activities to inspect and replace the lugs. Contact: H. Wong (510)975-0296 J. Russell (714)492-2641