Section
Resolution Product Category
Facilities Type
Related Technical Area
Image
NUREG 0933
Displaying 26 - 48 of 48
DESCRIPTION Background This issue was raised in Board Notification No. 82-81 [1] and addressed the failure of control rod drive (CRD) guide tube support pins in W reactors. The first pin failure at a U.S. plant occurred at North Anna 1 in 1982 where a …
1
DESCRIPTION Historical Background During the period 1978 to 1980, there were reports of fatigue failure of thermal sleeve assemblies in the piping systems of both PWRs and BWRs. The BWR problem was addressed by GE in NEDO-21821 and was resolved with a …
1
DESCRIPTION Historical Background STS for newer OLs require licensees to keep account of the number of transient occurrences to ensure that transient limits, based on design assumptions, are not exceeded. However, a number of older plants for which …
1
DESCRIPTION Historical Background On March 18, 1983, B&W expressed [1] concern for unanalyzed reactor vessel thermal stress that could occur during natural convection cooldown of PWRs. The concern emerged from a preliminary B&W evaluation of a voiding …
1
DESCRIPTION Historical Background This issue was identified by the ACRS in 1978 during the operating license reviews of some BWRs. The ACRS posed questions concerning the likelihood and effects of a LOCA which could cause interactions with the CRD …
1
DESCRIPTION Historical Background The risks of beyond design basis accidents in the spent fuel storage pool were examined in WASH-1400 [1] (App. I, pp. I-96ff). It was concluded that these risks were orders of magnitude below those involving the reactor …
1
DESCRIPTION This issue was raised by the ACRS in a memorandum [1] to the Commission in October 1983. Following the TMI-2 accident, the purpose and use of PORVs had been the subject of considerable analyses and discussion. The original purpose for which …
1
DESCRIPTION Historical Background In March 1982, leaks were detected in the heat-affected zones of the safe-end-to-pipe welds in two of the 28 in. diameter recirculation loop safe ends at Nine Mile Point Unit 1. Subsequent UT revealed extensive cracking …
1
DESCRIPTION Historical Background Low temperature overpressurization originally identified in NUREG 0371 [1] as item A-26. This issue later became USI A-26 and was resolved in September 1978 with a revision to SRP [2] Section 5.2. The resolution of USI …
1
DESCRIPTION Historical Background This issue was identified during the staff review of the Indian Point 2 and Zion PRAs [1] ; in both of these studies, the dominant interfacing systems LOCA events were estimated to be through the RHR suction valves. The …
1
DESCRIPTION In the prioritization of Issue 22, "Inadvertent Boron Dilution," it was found that inadvertent boron dilution events during cold shutdown operation do not constitute a significant risk to the public. Further work by DSI confirmed this …
1
DESCRIPTION Historical Background Potential stress corrosion cracking (SCC) of reactor vessel (RV) closure studs was raised as a GSI in December 1984. [1] Concerns were expressed that two contributors to SCC had not been subject to careful research and …
1
DESCRIPTION In an August 1983 memorandum, [1] the EDO requested a comprehensive review of NRC requirements in the area of nuclear power plant piping. In response to this request, the NRC Piping Review Committee (PRC) was formed to review and evaluate …
1
DESCRIPTION Historical Background Potential seismic interaction involving the movable in-core flux mapping systems was identified as a generic issue in August 1985. [1] This potential interaction exists because portions of the in-core flux mapping system, …
1
DESCRIPTION To calculate the value of RT PTS as required in 10 CFR 50.61 and 10 CFR 50, Appendix G, licensees must determine the value of the fast neutron fluence on the inside surface of their pressure vessels. Through a number of reviews, NRR found [1] …
1
DESCRIPTION The issue of fatigue of metal components was identified in SECY-93-049 [1] following the staff's senior management review of key license renewal issues. The recommendation to treat fatigue of metal components as a generic safety issue was …
1
In November 1992, two engineers who had previously worked under contract for the Pennsylvania Power and Light Company (PP&L) filed a report contending that the design of the Susquehanna station failed to meet regulatory requirements with respect to …
1
DESCRIPTION Historical Background The Office of Nuclear Reactor Regulation (NRR) identified this issue in April 1999, [1] when the concern was raised that licensees operating within the regulatory guidelines of Generic Letter (GL) 85-11, Completion of …
1
DESCRIPTION The risk of failure from fatigue of various reactor coolant system components was studied under Issue 78 and later integrated into the NRR Fatigue Action Plan which was completed and documented in SECY-95-245. [1] The staff concluded that the …
1
DESCRIPTION Historical Background This issue was raised [1] , [2] by an NMSS staff member whose concern arose from the observation that spent fuel pool racks using Boral for neutron absorption had experienced some problems with swelling and degradation of …
1
DESCRIPTION Historical Background This issue was initiated [1] in response to a recommendation in the screening analysis of Generic Issue (A) I-195, "Potential Hydrogen Combustion in BWR Piping." GI-195 investigated the potential safety …
1
DESCRIPTION Historical Background Spent fuel pools (SFPs) at PWRs are Seismic Category I structures that contain borated water, maintain spent fuel temperatures, and provide radiation shielding. The SFPs are typically lined with stainless steel plates, …
1
DESCRIPTION This issue was identified by an NMSS engineer in December 2006 and addressed concerns about potential safety issues with cranes that are used to lift spent fuel casks at nuclear power plants. The areas of concern involved questions about the …
1
Page Last Reviewed/Updated 3/1/2026
Disclaimer: Some of the formatting in NUREG-0933 may not be correct. We are currently working on fixing the formatting.