Headquarters Daily report JULY 14, 1995 *************************************************************************** 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 JULY 14, 1995 Licensee/Facility: Notification: Northeast Utilities MR Number: 1-95-0091 Millstone 1 Date: 07/14/95 Waterford,Connecticut RI PC Dockets: 50-245 BWR/GE-3 Subject: LNP Logic Problem Forced Shutdown Reportable Event Number: N/A Discussion: On June 26, 1995, the licensee identified a single failure vulnerability with the Unit 1 loss of normal power (LNP) logic that would prevent both emergency power sources from performing their design safety function. This issue was identified during the final review of the split bus LNP logic modification planned for implementation during refueling outage 15. The licensee declared both emergency power supplies inoperable and performed a plant shutdown required by technical specifications on June 27, 1995. During the outage the licensee implemented logic modifications to resolve the LNP logic problem. While shutdown the licensee also identified a number of discrepancies with the Standby Gas Treatment (SGTS) system that could have resulted in loss of secondary containment during an accident. These problems were also resolved with logic changes, system modifications, and the installation of a backup air system for the SGTS dampers prior to startup. On July 9, 1995, during the subsequent startup the licensee exceeded 212 degrees fahrenheit while continuing to vent the containment via the unfiltered reactor building ventilation system. This is prohibited by Technical Specification 3.7.B.6 which requires the containment venting via the SGTS system when greater than 212 degrees fahrenheit. The licensee recognized the error approximately 2 hours later and immediately shifted the ventilation lineup as required. This event occurred following a special test condition which required the isolation and draining of the shutdown cooling system to perform local leak rate testing of system containment isolation valves. The operators failed to implement the startup procedure which would have established containment integrity because the special test procedure did not integrate well with the startup procedure. The testing was necessary because of apparent thermal binding and subsequent forcing open of the shutdown cooling isolation valves during the plant shutdown. The containment venting violation occurred due to inadequate attention to, and operator control of, the vulnerability of the special test condition. The technical resolutions of these issues were reviewed by NRC before plant restart. Unit 1 achieved 100% power on July 13, 1995. Regional Action: The resident inspectors are following licensee response to this event. Contact: Paul Swetland (203)447-3179 Larry Nicholson (610)337-5128 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III JULY 14, 1995 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-95-0121 Dresden 3 Date: 07/14/95 Morris,Illinois RIII VIA LAN Dockets: 50-249 BWR/GE-3 Subject: FAILED MAIN TURBINE BLADE (UPDATE) Reportable Event Number: 28859 Discussion: As reported on May 28, 1995, the Unit 3 reactor tripped from full power due to a main turbine high vibration trip. The high vibration was caused by a failed blade in the "C" low pressure (LP-C) turbine rotor. Visual inspections identified one blade on the last stage rotor missing an 8-inch section and two additional bent blades. The licensee has concluded the root cause for the turbine blade failure was "high cycle fatigue failure" originating in the heat affected zone of the Stellite erosion shield on the leading edge of the blade. Chemical analysis of the Stellite material indicated that the "reverse engineered" ABB supplied blade did not meet General Electric's (GE) original "Haynes Alloy 6B" material specification. The use of non-6B Stellite material made the blade more susceptible to fatigue cracking. The failed blade was one of 425 last stage blades supplied by ABB for the Unit 3 LP turbines. Four hundred of the 425 ABB blades were non-6B Stellite material and approximately 30 percent of those 400 blades had crack indications. The ABB blades were only used in the last stage of the LP turbines. The licensee is replacing all of the Unit 3 ABB blades with GE blades. Unit 3 is currently scheduled to start up in mid-August 1995. Unit 2, currently in a refuel outage, has 19 ABB blades installed in the LP turbines. None of the 19 blades had indications of cracks. The licensee has confirmed that two of the blades were non-6B Stellite material. The blades will be replaced prior to Unit 2 start up. Quad Cities (QC) was the only other facility supplied with ABB "reverse engineered" LP turbine blades. The LP turbines for QC Unit 2, currently in a refueling outage, were inspected and no ABB blades were identified. The number of ABB blades in the QC Unit 1 LP turbine was unknown. The licensee planned to inspect the QC Unit 1 turbine during the upcoming refueling outage in the spring of 1996. Regional Action: Resident and regional inspectors are following the licensee's investigation. Contact: P.L. HILAND (708)829-9603 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III JULY 14, 1995 Licensee/Facility: Notification: Northern States Power Co. MR Number: 3-95-0122 Monticello 1 Date: 07/14/95 Monticello,Minnesota NONE Dockets: 50-263 BWR/GE-3 Subject: HOT WEATHER ISSUES Reportable Event Number: N/A Discussion: Daily temperatures as high as 98 degrees have resulted in record NSP grid loading. The grid is currently on system condition 5. Where condition 7 is normal, condition 6 is largely an economy alert, condition 5 is burning oil and condition 4 would be the loss of a major unit and could result in a system instability. Heat related issues at Monticello include compensatory measures to prevent the upper and lower safety related 4160 switchgear room equipment from exceeding its qualified temperature of 104 degrees. These measures include the placement of several temporary fans to move air through opened fire doors and the installation of temporary chillers to help cool the area. The chillers are being supplied with water from a nearby fire water header. Regional Action: The inspectors will follow this issue. Contact: M. PHILLIPS (708)790-5530