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NUREG 0933

Displaying 51 - 65 of 65

DESCRIPTION Historical Background This issue was raised [1] in March 1985 to address the staff's concern that there were no requirements for dynamic qualification testing or dynamic surveillance testing of large bore hydraulic snubbers (> 50 kips load …
DESCRIPTION The loss of all feedwater event at Davis-Besse on June 9, 1985, resulted in the formation of an NRC project team to investigate the event. The team's findings were published in NUREG-1154 [1] and were subsequently reviewed by DL/NRR. As a …
DESCRIPTION Historical Background This issue was identified in the U.S. Nuclear Regulatory Commission (NRC) incident investigation team (IIT) report on the loss of integrated control system (ICS) power event at Rancho Seco Nuclear Generating Station …
DESCRIPTION Historical Background This issue was identified [1] by NRR as a result of concern for the potential loss of the RHR system under a harsh containment environment. The RHR system is normally located outside the containment and is not required to …
DESCRIPTION Historical Background Large-break loss-of-coolant accidents (LBLOCA) with consequential steam generator tube ruptures (SGTR) was identified as a GSI in a DRPS/RES memorandum [1] on April 28, 1987. The issue surfaced as a result of the proposed …
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 Historical Background This issue was identified [1] by NRR after reactor operating experience and research results on MOVs, SOVs, AOVs, and HOVs indicated that testing under static conditions did not always reveal how these valves would …
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 …
This issue has two parts that were evaluated separately. ISSUE 174.A: SONGS EMPLOYEES' CONCERN DESCRIPTION Historical Background A San Onofre Nuclear Generating Station (SONGS) employee filed a concern with the SONGS Employee Program concerning the …
DESCRIPTION Core design is a fundamental component of plant safety because maintaining fuel integrity is the first principal safety barrier (i.e., fuel cladding, reactor coolant system boundary, or the containment) against serious radioactive releases. …
DESCRIPTION Historical Background This issue was identified [1] following an NRR request for reconsideration of the safety priority ranking (DROP) of GSI-22, "Inadvertent Boron Dilution Events," based on new information on high burn-up fuel and new …
DESCRIPTION NRC regulatory requirements include the estimation of individual offsite dose from the design basis LOCA. The fission product source term in TID-14844 [1] which is referenced by the regulations, has historically been used for this application. …
EXECUTIVE SUMMARY The issue of potential blockage in the containment sumps was first identified in Unresolved Safety Issue (USI) A-43, "Containment Emergency Sump Performance." It identified a concern for the availability of adequate recirculation cooling …
DESCRIPTION Historical Background This issue was identified [1] , [2] by a Region III inspector and addressed the possible failure of low pressure emergency core cooling systems due to unanticipated, large quantities of entrained gas in the suction piping …
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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