Headquarters Daily report DECEMBER 29, 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 DEC. 29, 1994 MR Number: H-94-0120 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 94-90, "Transient Resulting in a Reactor Trip and Multiple Safety Injection System Actuations at Salem," to be issued December 30, 1994. The NRC is issuing this information notice to alert addressees to the events associated with the loss of circulating water at Salem Nuclear Power Plant, Unit 1, on April 7, 1994, that led to a reactor trip followed by multiple automatic actuations of the safety injection system. Technical contacts: Robert J. Summers, RI (609) 935-3850 Eric J. Benner, NRR (301) 504-1171 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION II DECEMBER 29, 1994 Licensee/Facility: Notification: Georgia Power Co. MR Number: 2-94-0112 Hatch 1 Date: 12/29/94 Baxley,Georgia Dockets: 50-321 BWR/GE-4 Subject: SPENT FUEL POOL STAINLESS STEEL LINER RECEIVED 3" GASH WHEN CORE SHROUD HEAD BOLT WAS DROPPED Reportable Event Number: 28194 Discussion: At 8:53 p.m. ET on 12/28/94, the licensee was removing the second of seven used core shroud bolts from the spent fuel pool (SFP) for shipment offsite. The bolts were found to be defective and had been removed in the most recent Unit 1 refueling outage. The crimping on the looped 3/16" steel cable that was supporting one bolt failed and the bolt fell into the pool creating a three inch gash in the stainless steel liner. The dropped bolt is resting against the side of the SFP wall where it fell in a near vertical position. The other five are hanging on the side of the SFP wall. The bolt was approximately one foot above the pool water surface when it fell. Pool level dropped approximately 3 inches (1" = Approx. 850 gallons) as the annulus between the concrete and the liner was filled which resulted in a trip of the SFP cooling pump on low suction pressure. The leakage from the pool through the gash has been contained by the surrounding concrete liner. Approximately 2000 gallons had drained to the northeast equipment drain sump before the annulus drain valve was closed per procedure. An estimated 400 gallons of water filled the annulus between the liner and the outer wall. The licensee refilled the pool, is monitoring leakage, and returned the SFP cooling system to service. No further makeup has been necessary after the water level was initially restored. As of 5:00 a.m. 12/29 the level has decreased approximately 1/2 inch (425 gallons) due to seepage through penetrations in the concrete liner. The licensee is collecting this leakage and directing it to reactor building floor drains. The resident inspectors verified the fuel pool gates were in place so Unit 2 is not affected. The direct cause of the dropped bolt was a rigging failure. The bolt was suspended by a 3/16 inch stainless steel cable sling and a standard nylon sling from the refuel floor auxiliary hoist. The stainless sling had two eyelets, one on each end. The eyelets had been formed by joining the cable to itself using two "Nicopress Oval Sleeves." These sleeves are stainless steel bands which are pressed to the cable using a special crimping tool. Each of the sleeves were double crimped. With the load suspended out of the water, the dead end of the upper eyelet on the stainless steel cable came out of the two crimp sleeves causing the load to fall. The residents are investigating whether or not the slings were properly load tested before use. Radiation levels on the refuel floor did not noticeably change as a result of the slight decrease in SFP level. Two people standing next to the bolt as it dropped into the pool did get some water splashed on them as the bolt fell into the pool but they were not contaminated. The licensee has contacted divers to perform underwater weld repairs (estimated to be performed on 12/31/94 or 1/1/95). The bolts read approximately 3 rem/hour on contact and must be moved prior to doing repairs. Spent fuel must also be moved to lower radiation levels in the area for the divers. A temporary weight with a gasket is available to place over the hole if necessary as a temporary patch. Regional Action: The Senior Resident Inspector responded to the site when informed by the licensee and is following licensee corrective actions. Contact: STEVE CAHILL (404)331-4198 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV DECEMBER 29, 1994 Licensee/Facility: Notification: Nebraska Public Power District MR Number: 4-94-0151 Cooper 1 Date: 12/29/94 Brownsville,Nebraska Senior Resident Inspector Dockets: 50-298 BWR/GE-4 Subject: INADVERTENT ADDITION OF SODIUM PENTABORATE SOLUTION TO THE REACTOR VESSEL Reportable Event Number: N/A Discussion: On December 28, 1994, at approximately 8:30 p.m. (CST) the licensee discovered that sodium pentaborate solution, at 12-16 weight percent, from the standby liquid control system, was inadvertently transferred to the reactor coolant system. The reactor was and remains in a cold shutdown condition with fuel in the vessel. The reactor has been shut down since May 25, 1994. The licensee had been conducting a surveillance test of the standby liquid control system which involved transferring demineralized water from a test tank through the system's positive displacement pump and explosively operated isolation (Squib) valves to the reactor vessel. The test had been completed and procedural steps instructed personnel to install a blank flange in the position of the squib valves. For reasons not known at this time, these steps were not performed and the operator proceeded to the step which required the realignment of the system pumps to the standby liquid control storage tank. At this time, the licensee believes the alignment allowed for a gravity drain path from the standby liquid control tank to the vessel. Operations became aware of the event when it received indications of high conductivity in the reactor water cleanup system and an annunciator indicating a lowering of the level in the standby liquid control storage tank. The licensee indicates 246 gallons of solution were transferred. Conductivity increased from a normal of 0.09 micromhos to 89 micromhos and pH increased from 6.4 to 8.6. The flowpath was isolated and the licensee initiated a review board as part of its corrective action program. Preliminary information from the licensee indicates that the nonlicensed operator performing the test steps in the field had been certified just last week, had not previously performed the task, and communications with a licensed control room operator who had performed the task were inadequate. Licensee management has curtailed all but critical work at the site due to this event and has scheduled informational meetings with all shift personnel to further communicate management expectations. Critical work is that associated with reactor cleanup and some essential surveillances. It has not been determined when normal production work will resume. The licensee has contacted the NSSS vendor, GE, for assistance in cleanup and analysis of effects of the solution on reactor vessel internals. Regional Action: The Region plans followup inspections to assess the licensee's root cause analysis. Contact: P. Harrell (817)860-8250 R. Kopriva (402)825-3371