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Morning Report for August 5, 1999
Headquarters Daily Report AUGUST 05, 1999 *************************************************************************** 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 AUGUST 5, 1999 Licensee/Facility: Notification: Part 21 Database MR Number: H-99-0068 Rosemount Date: 08/05/99 Subject: Part 21 - Potential problem with Rosemount pre-1987 trip units Discussion: VENDOR: Rosemount PT21 FILE NO: 99-31-0 DATE OF DOCUMENT: 06/18/99 ACCESSION NUMBER: SOURCE DOCUMENT: EN 35844 REVIEWER: REXB, D. Skeen NEW ISSUE. On June 18, 1999, the NRC Operations Center received a letter from Rosemount Nuclear Instruments, Incorporated, concerning a potential problem with a specific capacitor used in the circuit boards of Model 510DU and 710DU trip units. These trip units are widely used in BWR plants in various applications to provide inputs to the nuclear steam supply shutoff system (NSSSS) as well as to provide signals to the primary containment isolation system. On October 8, 1987, the BWR Owners Group (BWROG) Scram Frequency Reduction Maintenance Committee requested information from Rosemount after a number of BWR utilities experienced failure of the Model 710 analog trip circuit board due to short circuiting of the power input capacitor (designated as C25 on the circuit board). On October 20, 1987, Rosemount responded to the BWROG, explaining that the issue had been identified by its internal returned goods tracking system. As a result, the vendor performed extensive testing in the spring of 1987 and determined that the capacitors would only fail when subjected to environmental parameters (temperature, voltage) outside of normal operating conditions. However, the vendor acknowledged that a contaminant, such as moisture introduced into the capacitor could cause the type of failure described by the customers. In May 1987, the vendor upgraded the trip card with a more reliable capacitor with enhanced sealing against contamination. Thus, C25 capacitors with a date code of 8630 or higher are not susceptible to failure due to contamination. Since 1987, the vendor has identified five more confirmed failures of the pre-8630 C25 capacitors and 14 cases where the capacitor was replaced by vendor technicians while repairing trip units, indicating that the capacitor may have played a role in their failure. The vendor's June 18, 1999 letter alerted its BWR customers that further examination of the capacitors may be warranted to determine if replacement is necessary. Rosemount is preparing a procedure to be made available to customers at no charge for licensees who may wish to rework existing trip units. NRC staff discussed the issue with Rosemount in a telephone conversation on June 21, 1999. Rosemount confirmed that the Model 510 and 710 trip units are only used in BWR applications. The vendor stated that the 4-digit date code on the capacitor is located on one side of the capacitor at the bottom of a list of other numbers. The vendor HEADQUARTERS MORNING REPORT PAGE 2 AUGUST 5, 1999 MR Number: H-99-0068 (cont.) acknowledged that the capacitor may not always be oriented on the circuit board to enable easy reading. The vendor is working to identify trip units with the pre-8630 date codes by serial number to make it easier for customers to identify suspect trip units. Once the units have been identified by serial number, Rosemount will notify affected customers. Contact: Dave Skeen, NRR 301-415-1174 E-mail: dls@nrc.gov _ HEADQUARTERS MORNING REPORT PAGE 2 AUGUST 5, 1999 MR Number: H-99-0069 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS Subject: Issuance of Information Notice 99-25 NRC Information Notice 99-25: Year 2000 Contingency Planning Activities dated August 10, 1999 The U.S. Nuclear Regulatory Commission is issuing this information notice to inform addressees about contingency planning activities being undertaken by the NRC in response to potential disruptions of telecommunications and electrical distribution systems that could occur during the Year 2000 (Y2K) transition period (December 31, 1999, through the first few days of 2000). Technical Contacts: Joseph Giitter, IRO John Jolicoeur, IRO 301-415-7485 301-415-6383 E-mail: jgg@nrc.gov E-mail: jrj1@nrc.gov _ HEADQUARTERS MORNING REPORT PAGE 3 AUGUST 5, 1999 Licensee/Facility: Notification: Part 21 Database MR Number: H-99-0070 Nuclear Logistics Inc. Date: 08/05/99 Subject: Part 21 - Potential premature overvoltage protection actuation in dc power supply during diesel generator loading Discussion: VENDOR: Nuclear Logistics PT21 FILE NO: 99-30-0 DATE OF DOCUMENT: 06/01/99 ACCESSION NUMBER: 9906070115 SOURCE DOCUMENT: EN 35782 REVIEWER: REXB, D. Skeen NEW ISSUE. The vendor, Nuclear Logistics Incorporated (NLI) reports a deviation in a direct current power supply, part number P/N NLI-LGS-G-24-OV-R-8018, supplied as a Class 1E component. The observed deviation was a premature overvoltage protection actuation during diesel generator loading. This condition was determined to be a deviation on April 19, 1999, but the vendor has not been able to duplicate the condition in laboratory testing. The affected utility is Public Service Electric and Gas Company. The vendor notified four other nuclear customers, including Florida Power and Light, Baltimore Gas and Electric, Omaha Public Power District, and Virginia Power Company which also have NLI-L Series power supplies, but NLI has not received any other reports of power supply problems from those customers. The vendor plans on witnessing testing of the suspect power supplies in situ at Public Service Electric and Gas Company later this month to determine the root cause of the overvoltage protection circuitry actuation. Information provided to NLI by the licensee indicates that the power supply, designed to provide 50 amps at 24 V-dc and to provide protection of the power supply from overvoltage conditions when the output voltage exceeds 27V-dc, was installed in the emergency diesel generator control panel along with several control relays which are required to cycle during diesel generator starting and loading. One possible theory is that cycling of the relays may cause voltage spikes in the power supply of sufficient magnitude to actuate the overvoltage protection circuitry and terminate the power supply output. The vendor will evaluate the test data, and if it is determined that there is a design deficiency, other NLI-L Series power supplies will be tested to ascertain their susceptibility to this problem. _ REGION I MORNING REPORT PAGE 4 AUGUST 5, 1999 Licensee/Facility: Notification: Connecticut Yankee Atomic Power Co. MR Number: 1-99-0028 Haddam Neck 1 Date: 08/05/99 Hartford,Connecticut Licensee Telecon Dockets: 50-213 PWR/W-4-LP Subject: Stand-Down at Haddam Neck to Raise Safety Awareness Discussion: On August 4, 1999, Bechtel, the Decommissioning Operations Contractor for the Haddam Neck facility, issued a Stop Work Order. Within the last month, many new workers were hired and decommissioning activities were initiated. The licensee stated that some of these activities were not conducted consistent with Bechtel's expectations, including a few recordable OSHA incidents of minor safety significance. As of today (August 5), Bechtel has conducted an all-hands meeting to review the work practices and has conducted feedback sessions with its foreman and work crews. Some limited work activities are expected to resume today. However, the majority of the work will not resume until the worker feedback is evaluated, a hazard assessment is conducted by Bechtel to develop a corrective action plan, a detailed pre-job brief is conducted with every crew, and a safe work observation program is initiated. Most work is anticipated to resume next week. The licensee provided a courtesy notification to the NRC and also plans to highlight in their daily newsletter the efforts by Bechtel to improve safety awareness with its new workers. NRC informed the State of Connecticut. Regional Action: NRC will review this matter as part of its routine inspection program schedule for next week. Contact: Ronald Bellamy (610)337-5200 Marie Miller (610)337-5205 _
Page Last Reviewed/Updated Thursday, March 29, 2012
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