NUREG 0933
Displaying 1 - 24 of 24
DESCRIPTION The issue was raised after the occurrence of various incidents of water hammer that involved steam generator feedrings and piping, emergency core cooling systems, RHR systems, containment spray, service water, feedwater, and steam lines. The …
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DESCRIPTION By letter dated June 18, 1975, licensees of operating reactor facilities were sent a preliminary copy of a staff paper, "Guidance for Proposed License Amendments Relating to Refueling," and "Refueling Information Request Form." The purpose was …
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DESCRIPTION Historical Background This NUREG-0371 [1] item involves the development of consistent and formalized acceptance criteria regarding the conversion to higher density storage racks (increased storage capacity) in existing spent fuel storage …
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DESCRIPTION Historical Background The safety concern of this NUREG-0371 [1] item deals with the consideration of alternatives to the basic design of nuclear power plants with the emphasis primarily on reduction of the vulnerability of reactors to …
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DESCRIPTION Historical Background Individual reactor fuel rods sometimes fail during normal operations and many fuel rods are expected to fail during severe accidents. To ensure that these fuel failures do not result in unacceptable releases to the …
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DESCRIPTION This NUREG-0471 [1] task covers a spectrum of technical efforts related to the staff review of LMFBR fuel designs. The efforts include: (1) evaluating licensing requirements for the behavior of stainless steel cladding and hexcans in an LMFBR …
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DESCRIPTION The fuel assembly is a highly nonlinear structure which can be subjected to substantial loadings during seismic excitations and LOCA transients. The integrity of this assembly is critical for plant safety. Extensive work has been completed by …
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DESCRIPTION BWRs are operated in such a manner as to attempt to produce an axial power distribution with as little peaking as possible. When the reactor moderator is not boiling (e.g., during startup and heatup), the axial flux distribution is much more …
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DESCRIPTION This issue was raised in an AEOD memorandum [1] to NRR and OIE in October 1980 and addressed the problem of flow blockage by Asiatic clams (Corbicula) in redundant safety-related cooling water systems at Arkansas Nuclear One. CONCLUSION This …
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DESCRIPTION Historical Background On June 19, 1981, AEOD issued a preliminary report [1] on the incident at Calvert Cliffs Unit 1 in which the plant lost both redundant trains of service water when the service water system became air-bound as a result of …
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DESCRIPTION While operating at 100% power on March 10, 1980, San Onofre Unit 1 experienced a complete loss of the salt water cooling system. The event involved an unlikely triple failure and desiccant contamination of the instrument air system was found …
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DESCRIPTION Historical Background This issue was raised in a DL memorandum [1] to DST in March 1982 and addressed the subject of service water system (SWS) fouling at operating plants primarily by aquatic bivalves. Prior to and following this memorandum, …
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DESCRIPTION This issue was raised in an AEOD memorandum [1] to NRR in May 1982 and addressed the problem of flow blockage by blue mussels (Mytilus Edilus) in the reactor building closed cooling water system at Pilgrim. CONCLUSION This issue has been …
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DESCRIPTION Historical Background In response to a 1967 ACRS concern relative to the potential of melting and subsequent disintegration of a portion of a fuel assembly due to inlet orifice flow blockage, GE submitted NEDO-10174 [1] in May 1970. As a …
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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 …
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DESCRIPTION Historical Background In October 1982, the Executive Director for Operations appointed the Committee to Review Safety Requirements at Power Reactors (CRSRPR) to review U.S. Nuclear Regulatory Commission (NRC) security requirements at nuclear …
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DESCRIPTION Historical Background Experiments conducted at several test facilities prior to 1984 showed that irradiated fuel can fragment (crumble) into small pieces during a LOCA. Some evaluation of this effect was made for NRC by EG&G. [1] Although it …
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DESCRIPTION Historical Background This issue was identified [1] when the staff found the Byron Unit 1 vulnerable to core-melt sequences in the absence of the availability of Byron Unit 2 which was not yet operational. Because of the licensing status of …
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DESCRIPTION Historical Background The reliability of essential service water (ESW) systems and related problems have been an ongoing staff concern which has been documented in NUREG/CR-2797, [1] IE Bulletins 80-24 [2] and 81-03, [3] Generic Letter No. …
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DESCRIPTION Historical Background Following the TMI-2 accident, the NRC converted its fuel behavior research program into a severe accident research program and, consequently, no further confirmatory work on fuel damage criteria was pursued. However, some …
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DESCRIPTION Historical Background At 6:53 a.m. on February 7, 1993, an intruder drove into the TMI site owner-controlled area, through a gate into the protected area of Unit 1, and crashed through a roll-up door on the turbine building. TMI security …
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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. …
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DESCRIPTION The objective of this task was to respond to the Regulatory Review Group (RRG) Item #55. The RRG recommendations were to provide quicker review of core reload codes and to revise existing TS to permit changes, in accordance with approved core …
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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 …
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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.