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NUREG 0933

Displaying 26 - 45 of 45

DESCRIPTION An AEOD memorandum [1] to NRR on July 15, 1980, identified the concern that some operating nuclear power plants do not have technical specifications or Administrative controls governing operational restrictions for Class 1E 120 VAC vital …
DESCRIPTION Historical Background In an AEOD memorandum [1] to NRR, it was concluded that the design of the Point Beach Nuclear Plant, Units 1 and 2, under certain conditions, allowed manual interconnection of redundant electrical load groups, thereby …
DESCRIPTION Historical Background In August 1982, AEOD reviewed a number of LERs related to Class 1E safety related switchgear circuit breakers and found a high incidence of their failure to close on demand. A preliminary report was written and …
DESCRIPTION Historical Background This issue was identified at an NRC Operating Reactor Events meeting on January 7, 1982, [1] and addressed fire protection system (FPS) actuations that resulted in adverse interactions with safety-related equipment at …
DESCRIPTION Historical Background The containment flooding issue stems from a flooding event that occurred at the Indian Point 2 reactor in October 1980. [1] A large quantity of water leaked from fan coolers onto the containment building floor and …
DESCRIPTION Historical Background On November 11, 1981, the DAILY REPORT-REGION I carried a "prompt report" from Calvert Cliffs Units 1 and 2 indicating the licensee had been notified that the water tight integrity of the service water pump rooms in both …
DESCRIPTION Historical Background On August 12, 1983, one of the three emergency diesel generators (EDG) at the Shoreham Plant failed during overload testing as a result of a fractured crankshaft. The failure occurred in EDG-102 and similar crankshaft …
DESCRIPTION Historical Background The issue of using the most recent NOAA procedures for determining probable maximum precipitation (PMP) was raised [1] after an OL applicant disputed the NRC use of NOAA Hydrometeorological Report (HMR) Nos. 51 [2] and …
DESCRIPTION Historical Background This issue was identified in a DL/NRR memorandum [1] which called for an assessment of the high failure frequency of main transformers and the resultant safety implications. Concern for this issue arose when the North …
DESCRIPTION Historical Background This issue was identified in a DST/NRR memorandum [1] which addressed a condition in which some protective devices intended to trip active engineered safety features (ESF) components, under indication of equipment …
DESCRIPTION Historical Background This issue was identified in a RRAB memorandum [1] in March 1985 and addressed the possibility of relay contact chatter during a seismic event and its resulting effect upon safety and safety-related electrical control …
DESCRIPTION Following the NRR reorganization in November 1985, EIB/DSRO was responsible for resolving three issues that were directly related to onsite electrical systems: Issue 48, "LCO for Class 1E Vital Instrument Buses in Operating Reactors"; Issue …
DESCRIPTION Historical Background This issue was identified as an alternative approach to the Finding 15 recommendation [1] discussed in Issue 125.I.5, "Safety Systems Tested in All Conditions Required by DBA," which states that "[t]horough integrated …
DESCRIPTION This issue was identified [1] by NRR to address the concerns raised during the licensing of Nine Mile Point Unit 2. On February 7, 1985, Niagara Mohawk submitted to the NRC a report on "Non-Class 1E Devices Connected to Class 1E Power …
DESCRIPTION Historical Background This issue was identified [1] by NRR as a result of a diagnostic evaluation team inspection of the SWS at Zion, a multiplant site. The inspection identified the potential for some additional shared systems to have an …
DESCRIPTION As discussed in SECY-93-049, [1] the staff reviewed significant license renewal issues and found that several related to environmental qualification (EQ). A key aspect of these issues was whether the licensing bases, particularly for older …
DESCRIPTION Historical Background This issue was identified [1] by NRR following the issuance of NRC Information Notice (IN) 93-17 [2] which was based in part on a deficiency in the Surry Power Station emergency diesel generator (DG) loading. This …
In resolving GSIs over the years, the staff generally found it necessary to make assumptions and establish limitations on the scope of the issues. As a result of its review of the resolution of some GSIs, the ACRS expressed concerns that the assumptions …
DESCRIPTION On August 24, 1992, Hurricane Andrew hit south Florida and caused extensive onsite and offsite damage at Turkey Point. Following this hurricane which was classified Category 4, an NRC/industry team was organized to: (1) review the damage …
DESCRIPTION Historical Background This issue was identified [1] by NRR following an allegation that was submitted to the NRC in March 2006 that described a scenario in which a SBLOCA event in a PWR has progressed to the sump recirculation mode of core …

Page Last Reviewed/Updated 3/1/2026

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