Headquarters Daily Report MARCH 31, 1998 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS û REGION I û REGION II û REGION III û REGION IV û PRIORITY ATTENTION REQUIRED MORNING REPORT - HEADQUARTERS MARCH 31, 1998 Licensee/Facility: Notification: MR Number: H-98-0058 Vermont Yankee Date: 03/31/98 Subject: Metal Debris in GE9 Fuel Assembly at Vermont Yankee Discussion: The Vermont Yankee licensee found fretting failures in two adjacent GE9 fuel rods during a refueling outage on March 28, 1998 (EN #33990). The fretting was located about 1/2 inch above the lower tie plate. One of the two rods also had a 3-inch long crack in the cladding about 136 inches above the tie plate. The failures were apparently caused by fretting due to foreign material within the fuel bundle. The licensee believes the fretting failures were caused by a 1/8 inch x 1 1/2 inch long metal filing that was found in the bundle. In 1995, there was an issue with metal debris in GE fuels causing fretting at some BWR plants and GE issued a service information letter (SIL) to its customers. However, the metal filing found at Vermont Yankee is larger and appears to be different than the metal debris discussed in the GE SIL. The licensee does not believe that this event is related to the previous generic GE debris problem. Background: The NRC became aware of an issue involving metal shavings in some GE fuel types in January 1995. Plants reporting metal debris in fuel assemblies between February 1995 and June 1996 included Clinton, Fitzpatrick, Vermont Yankee, and Oyster Creek. Some Type GE8, GE9, and GE10 fuel bundles were found to have the debris at the various plants. General Electric issued Service Information Letter No. 552, "Fuel Failures Caused By Metal Debris," on March 26, 1993 to notify customers of nuclear fuel damage caused by small (1/8 inch x 1/4 inch) metal debris trapped in fuel assemblies. The Clinton licensee was subsequently informed by GE in February 1995 that some fuel assemblies manufactured by GE Nuclear Fuels may contain small metal debris in the lower tie plate. The debris resulted from a lack of a mechanical process to remove it during manufacture and inadequate quality inspection methods at the end of the manufacturing process. GE subsequently implemented several process improvements to address the debris issue. Since the debris is typically found down in the grid of the tie plate, typical receipt inspection by licensees may not be adequate to identify it. Inspection using mirrors or fiber optics may be necessary to find it. Fuel with the channel already in place must have the channel raised about a foot to be inspected. On March 16, 1995, GE met with NRC staff to discuss the issue. As a result of the meeting, the staff concluded that a generic communication was not warranted because GE had informed all of its customers and revised its procedures to address the lower tie plate debris issue. Regional Action: The resident inspector will follow up on the Vermont Yankee event. HEADQUARTERS MORNING REPORT PAGE 2 MARCH 31, 1998 MR Number: H-98-0058 (cont.) References: NRC Morning Reports - MR 1-95-0024, Fitzpatrick, 2/16/95; MR 1-95-0027, Vermont Yankee, 2/17/95; MR 1-95-0030, Fitzpatrick, 2/24/95; MR 1-96-0063, Oyster Creek, 6/28/96 Contacts: William Cook, SRI (802) 257-4319 Email: wac1@nrc.gov Dave Skeen, NRR (301) 415-1174 Email: dls@nrc.gov _ REGION I MORNING REPORT PAGE 2 MARCH 31, 1998 Licensee/Facility: Notification: Peco Energy Company MR Number: 1-98-0016 Peach Bottom 3 Date: 03/26/98 Philadelphia,Pennsylvania Dockets: 50-278 BWR/GE-4 Subject: FOREIGN MATERIAL CONTROL DURING SUCTION STRAINER REPLACEMENT Discussion: On March 26, 1998, with Unit 3 shutdown for a maintenance outage, while removing the internals of the 3A core spray pump to determine the cause for the 3A core spray pumps inability to satisfy pump curve acceptance criteria, the licensee found foreign material wrapped around the pump impeller shaft which covered part of the impeller vanes. The material was determined to be a "rigging sling protector" which was used during the suction strainer replacement performed during the October 1997 refuel outage. The "rigging sling protector" was nominally a 4 inch by 12 inch by 3/4 inch piece of white and red fibrous material. It was most likely that the "rigging sling protector" was introduced inside of the core spray piping rather than going through the suction strainer. The licensee's Foreign Material Exclusion (FME) program at the start of the outage logged all the material introduced into the torus and that material removed. However, on day 27 of the outage, with about 4,000 items logged into the torus and about 2,000 logged out, the licensee changed the FME control of logging in and out and replaced the FME control with torus catwalk walkdowns and diver walkdowns of the torus portion underwater. These walkdowns were capable of detecting foreign material in the torus, but were not capable of detecting foreign material inside of the piping with the suction strainers in place. The licensee has completed 4 hour pump runs in the torus to torus mode for all of the Unit 3 RHR and core spray pumps and has concluded that all pumps are operable. The resident staff will document this event and the licensee's corrective actions in a special inspection report. Contact: Cliff Anderson (610)337-5227 Tony McMurtray (717)456-7614 _