Headquarters Daily report SEPTEMBER 15, 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 - REGION I SEPTEMBER 15, 1994 Licensee/Facility: Notification: Northeast Utilities MR Number: 1-94-0106 Millstone 3 Date: 09/15/94 Waterford,Connecticut SRI PC Dockets: 50-423 PWR/W-4-LP Subject: REACTOR COOLANT SYSTEM PRESSURE BOUNDARY LEAKAGE Reportable Event Number: 27772 Discussion: Following a plant shutdown due to a slow partial stroke time on the `C' main steam isolation valve, the licensee performed a walkdown of containment and found a significant boron accumulation from one of the four pipe bosses leading to the reactor coolant system (RCS) flow instruments in loop `C'. The licensee found a 5/8" crack in the socket weld that connects the flow instrument pipe to the pipe boss. The leakage was not sufficient to be identified by RCS leak rate calculations, containment sump levels, or the containment radiation monitor. Since the area of the leaking weld was not accessible at power, the leak was not identified until the containment walkdown following the shutdown on September 9, 1994. The defective weld was cut in half and an initial examination showed that a lack of fusion between the weld material and the pipe boss may have initiated the crack. The removed weld was sent to a Combustion Engineering laboratory for a detailed examination to confirm that the lack of fusion initiated the crack and attempt to identify what propagated the crack. Crack propagation is typically caused by vibration or thermal stresses. The defective welds were likely caused by welder error due to the difficult location of the welds. The licensee performed liquid penetrant (PT) testing on the other 15 RCS flow instrumentation penetrations and all connections were satisfactory. Even though it is not required by Code, the licensee performed eddy current testing and radiographic testing (RT) on all the flow instrument penetrations. The eddy current tests were inconclusive but the RT showed a potential lack of fusion on two flow instrument penetrations on the `B' RCS loop. The licensee decided to cut out and repair these welds also. All the repaired welds were RT'ed with satisfactory results. In 1992, a flow instrument penetration weld in RCS loop `D' leaked. The weld defect was inadvertently destroyed when cutting out the weld so the root cause could not be determined. The licensee surmised that a defective weld initiated the crack and vibration propagated the crack. The licensee took vibration measurements of all 16 loop flow penetrations and found that only the failed connection on loop `D' was near a resonant frequency. The licensee shortened this flow instrument pipe to change its natural frequency. At that time, the licensee also performed PTs of all 16 connections with satisfactory results. Regional Action: Routine resident inspector follow-up. Contact: Larry Nicholson (610)337-5128 Paul Swetland (203)447-3179 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III SEPTEMBER 15, 1994 Licensee/Facility: Notification: Northern States Power Co. MR Number: 3-94-0161 Monticello 1 Date: 09/15/94 Monticello,Minnesota RESIDENT INSPECTOR TELECON Dockets: 50-263 BWR/GE-3 Subject: REACTOR SHUTDOWN FOR 1994 REFUELING OUTAGE Reportable Event Number: N/A Discussion: On September 15, 1994, the plant was shutdown to commence the 1994 refueling outage. The outage is scheduled for a 39 day duration (September 15 - October 23). The outage scope includes core shroud inspection, in-vessel visual inspection, and core spray crack repair. These items will precede fuel shuffling during which 25 percent of the existing reactor core will be replaced. Regional Action: The resident and regional inspectors are continuing to monitor outage activities. Contact: M.P. PHILLIPS (708)829-9637 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV SEPTEMBER 15, 1994 Licensee/Facility: Notification: Gulf States Utilities Co. MR Number: 4-94-0096 River Bend 1 Date: 09/15/94 St Francisville,Louisiana Senior Resident Inspector Dockets: 50-458 BWR/GE-6 Subject: FIRE PROTECTION CO2 DISCHARGE Reportable Event Number: N/A Discussion: On September 14, 1994, at 10:48 a.m., the carbon dioxide system, which is designed to suppress fires around the main turbine bearings, actuated and partially discharged the storage banks. At the time, the plant was in cold shutdown following a reactor scram that occurred on September 8. The licensee immediately evacuated the turbine building and dispatched operators into the building, equipped with SCBA equipment and atmosphere monitors. The operators did not detect any oxygen deficient areas. No one was injured as a result of the release. The preliminary cause appeared to be a control system malfunction while maintenance was being performed on the system. The licensee is troubleshooting to determine what malfunctioned and to confirm the cause. Regional Action: Routine followup by the resident inspectors. Contact: P. H. Harrell (817)860-8250 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV SEPTEMBER 15, 1994 Licensee/Facility: Notification: Entergy Operations, Inc. MR Number: 4-94-0097 Arkansas Nuclear 1 2 Date: 09/14/94 Russelville,Arkansas Senior Resident Inspector Dockets: 50-313,50-368 PWR/B&W-L-LP,PWR/CE Subject: TEST RECORDS Reportable Event Number: N/A Discussion: On September 12, 1994, the licensee determined that two contract employees (Bechtel Power Corporation) had incorrectly completed test records at the Arkansas Nuclear One facility. The contract employees were performing a periodic inspection of fire extinguishers and had copied the fire extinguisher weights from an old inspection data sheet before actually weighing the fire extinguishers as required by the procedure. When questioned, the contractors stated it was their practice to copy the previous weights onto the new inspection data sheet and subsequently weigh the extinguishers to confirm the accuracy of the recorded data. The licensee concluded that the contractors knew that this practice was not in accordance with the test procedure. As a disciplinary measure, the licensee removed the contractors from the site and terminated their site access. The licensee is currently reviewing the contractors' past work assignments and their associated security access records to determine whether actual falsification of the records occurred. The licensee does not believe that the work assignments of the contractors had the potential to directly affect the operability of safety-related equipment. Regional Action: The Resident Inspectors will review the licensee's investigation into past work assignments. Contact: Chris VanDenburgh (817)860-8161