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in subjects: "Water Moderated Reactors 220900* -- Nuclear Reactor Technology-- Reactor Safety"

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TRAC development and assessment status

TRAC is being developed at the Los Alamos National Laboratory to provide an advanced systems code for light-water reactor accident analysis. The released TRAC versions (P1, P1A, and PD2) were intended primarily as benchmark codes for large-break loss-of-coolant accidents but PD2 has been applied successfully to TMI-type transients and other small-break transients. A fast-running version, PFl, is currently under development to address more efficiently and accurately these types of transients. Al… more

Date: January 1, 1981

Creator: Vigil, J. C. & Knight, T. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Drywell pressurization test for the NRC 1/5 scale pressure suppression experiment

A drywell pressurization test was conducted at LLL on February 1, 1977, as part of the NRC /sup 1///sub 5/ scale pressure suppression experiment. A series of four test runs were completed with predicted initial drywell pressurization rates of 14.0, 18.6, 23.0, and 26.0 psi/sec (96.5, 128, 159, and 179 kPa/sec). Each test run consisted of charging various combinations of bottles with nitrogen under high pressure, evacuating the drywell to /sup 1///sub 5/ atmosphere, and opening a valve between t… more

Date: February 21, 1977

Creator: Altenbach, T. J. & Pitts, J. H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Testing to evaluate synergistic effects from LOCA environments. Test IX. Simultaneous mode; cables, splice assemblies, and electrical insulation samples

This test was conducted to complement Test VIII which was a sequential test of cables, cable splices, and insulation samples. In this test, the generic LOCA environments (radiation, temperature, pressure, chemical spray) were simulated and simultaneously applied to the test items. There were no failures of any assemblies and all were able to function at rated current and voltage throughout the entire test. An additional parameter, dissipation factor, was monitored in this test and when used in … more

Date: April 1, 1978

Creator: Thome, Frank V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

BWR plant analyzer development at BNL (Brookhaven National Laboratory)

An engineering plant analyzer has been developed at BNL for realistically and accurately simulating transients and severe abnormal events in BWR power plants. Simulations are being carried out routinely with high fidelity, high simulation speed, at low cost and with unsurpassed user convenience. The BNL Plant Analyzer is the only operating facility which (a) simulates more than two orders-of-magnitude faster than the CDC-7600 mainframe computer, (b) is accessible and fully operational in on-lin… more

Date: 1986~

Creator: Wulff, W.; Cheng, H. S. & Mallen, A. N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Efficient method for simulation of BWR severe accident sequence events before core uncovery

BWR-LACP has been a versatile tool for the ORNL SASA program. The development effort was minimal, and the code is fast running and economical. Operator actions are easily simulated and the complete scope of both reactor vessel and primary containment are modeled. Valuable insights have been gained into accident sequences. A Fortran version is under development and it will be modified for application to Mark II plants.

Date: January 1, 1984

Creator: Harrington, R. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ORNL: PWR-BDHT analysis procedure, a preliminary overview

The computer programs currently used in the analysis of the ORNL-PWR Blowdown Heat Transfer Separate-Effects Program are overviewed. The current linkages and relationships among the programs are given along with general comments about the future directions of some of these programs. The overview is strictly from the computer science point of view with only minimal information concerning the engineering aspects of the analysis procedure.

Date: January 10, 1978

Creator: Cliff, S.B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Incorporation of various uncertainties in dependent failure-probability estimation. [PWR]

This paper describes an approach that allows the incorporation of various types of uncertainties in the estimation of dependent failure (common mode failure) probability. The types of uncertainties considered are attributable to data, modeling and coupling. The method developed is applied to a class of dependent failures, i.e., multiple human failures during testing, maintenance and calibration. Estimation of these failures is critical as they have been shown to be significant contributors to c… more

Date: January 1, 1982

Creator: Samanta, P.K. & Mitra, S.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Four-fluid model of PWR degraded cores

This paper describes the new two-dimensional, four-fluid fluid dynamics and heat transfer (FLUIDS) module of the MELPROG code. MELPROG is designed to give an integrated, mechanistic treatment of pressurized water reactor (PWR) core meltdown accidents from accident initiation to vessel melt-through. The code has a modular data storage and transfer structure, with each module providing the others with boundary conditions at each computational time step. Thus the FLUIDS module receives mass and en… more

Date: January 1, 1985

Creator: Dearing, J.F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Seismic risk assessment of a BWR: status report

The seismic risk methodology developed in the US NRC Seismic Safety Margins Research Program (SSMRP) was demonstrated by its application to the Zion nuclear power plant, a pressurized water reactor (PWR). A detailed model of Zion, including systems analysis models (initiating events, event trees, and fault trees), SSI and structure models, and piping models was developed and analyzed. The SSMRP methodology can equally be applied to a boiling water reactor (BWR). To demonstrate its applicability… more

Date: February 1, 1985

Creator: Chuang, T. Y.; Bernreuter, D. L.; Wells, J. E. & Johnson, J. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Analysis of hydrodynamic phenomena in simulant experiments investigating cavity interactions following postulated vessel meltthrough

An analysis of hydrodynamic phenomena in simulant experiments examining aspects of ex-vessel material interactions in a PWR reactor cavity following postulated core meltdown and localized breaching of the reactor vessel has been carried out. While previous analyses of the tests examined thresholds for the onset of sweepout of fluid from the cavity, the present analysis considers the progression of specific hydrodynamic phenomena involved in the dispersal process: crater formation due to gas jet… more

Date: January 1, 1984

Creator: Sienicki, J. J. & Spencer, B. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Overview of the LOFT experimental program

The Loss-of-Fluid Test (LOFT) facility, operated by EG and G Idaho, Inc., for the US Nuclear Regulatory Commission, is designed as an integral test facility to study the behavior of commercial pressurized water reactors (PWRs) during a loss-of-coolant accident (LOCA). For this mission, six nuclear and one nonnuclear test series have been proposed to provide data on PWR transient behavior, but plans must be recognized as tentative and subject to change for a number of reasons. The Nonnuclear Tes… more

Date: January 1, 1979

Creator: Burtt, J.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Analysis of LOFT Tests L2-2, L2-3 and L3-0

This paper describes LOFT Tests L2-2, L2-3, and L3-0 and presents conclusions reached from analysis of these tests. The LOFT L2 series of tests, called the power ascension series, originally consisted of six tests. The first four tests, L2-1 through L2-4, were identical except for step-wise increases in core power for each test. Comparison of these tests, and the nonnuclear Test L1-5, was planned to evaluate the effect of core power on system and ECC behavior during large cold leg break LOCA's.… more

Date: January 1, 1979

Creator: Leach, L.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Contributions from moderate frequency transient initiators in a BWR PRA

Transients are significant contributors to the core damage frequency in Boiling Water Reactors (BWR). The main contribution comes from transients with frequency of occurrence in the range of 3 to 100 events during plant lifetime (30 to 40 years). Examples of these transients are turbine trip, loss of condenser, and inadvertently open relief valve (IORV). Reviews by BNL of BRW PRAs appear to indicate that moderate frequency transients also could significantly contribute to the total core damage … more

Date: January 1, 1985

Creator: Ilberg, D.; Hanan, N. & Shiu, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Methods and benefits of experimental seismic evaluation of nuclear power plants. Final report

This study reviews experimental techniques, instrumentation requirements, safety considerations, and benefits of performing vibration tests on nuclear power plant containments and internal components. The emphasis is on testing to improve seismic structural models. Techniques for identification of resonant frequencies, damping, and mode shapes, are discussed. The benefits of testing with regard to increased damping and more accurate computer models are oulined. A test plan, schedule and budget … more

Date: July 1, 1979

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Equipment qualification issues research and resolution: Status report

Since its inception in 1975, the Qualification Testing Evaluation (QTE) Program has produced numerous results pertinent to equipment qualification issues. Many have been incorporated into Regulatory Guides, Rules, and industry practices and standards. This report summarizes the numerous reports and findings to date. Thirty separate issues are discussed encompassing three generic areas: accident simulation methods, aging simulation methods, and special topics related to equipment qualification. … more

Date: November 1, 1986

Creator: Bonzon, L. L.; Wyant, F. J.; Bustard, L. D. & Gillen, K. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Energy and technology review

Separate abstracts were presented for each of the 3 included sections.

Date: February 1, 1978

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Controlling Hydrogen Behavior in Light Water Reactors

In the aftermath of the incident at Three Mile Island Unit 2 (TMI-2), a new and different treatment of the Light Water Reactor (LWR) risks is needed for public safety because of the specific events involving hydrogen generation, transport, and behavior following the core damage. Hydrogen behavior in closed environments such as the TMI-2 containment building is a complex phenomenon that is not fully understood. Hence, an engineering approach is presented for prevention of loss of life, equipment… more

Date: January 1, 1981

Creator: Cullingford, Hatice S. & Edeskuty, Frederick J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Status and application of TRAC-BD1/MOD1 to benchmark data

The TRAC-BD1/MOD1 code can simulate a full range of operational transients and postulated accidents. It has been tested against a range of separate effects and systems test data and the agreement between the code simulation and the test data is good overall but specific areas of improvement remain. Work currently underway includes the development of a one-dimensional neutron kinetics model and a Courant limit violating numerical scheme to increase the computational speed of the code for simulat… more

Date: January 1, 1984

Creator: Weaver, W. L., III

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ORNL-PWR BDHT analysis procedure: an overview

The key computer programs currently used by the analysis procedure of the ORNL-PWR Blowdown Heat Transfer Separate Effects Program are overviewed with particular emphasis placed on their interrelationships. The major modeling and calculational programs, COBRA, ORINC, ORTCAL, PINSIM, and various versions of RELAP4, are summarized and placed into the perspective of the procedure. The supportive programs, REDPLT, ORCPLT, BDHTPLOT, OXREPT, and OTOCI, and their uses are described.

Date: January 1, 1978

Creator: Cliff, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Health physics and industrial hygiene aspects of decontamination as a precursor to decontamination

The Pacific Northwest Laboratory is conducting a comprehensive study of the impacts, benefits and effects of decontamination as a precursor to decommissioning for the US Nuclear Regulatory Commission. The program deals primarily with chemical cleaning of light-water reactor (LWR) systems that will not be returned to operation. A major section of this study defines the health physics and industrial hygiene and safety concerns during decontamination operations. The primary health physics concerns… more

Date: June 1, 1982

Creator: Card, C.J.; Hoenes, G.R.; Munson, L.F. & Halseth, G.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Seismic Qualification of Equipment by Means of Probabilistic Risk Assessment. [PWR]

Upon the sponsorship of the Equipment Qualification Branch (EQB) of NRC, Brookhaven National Laboratory (BNL) has utilized a risk-based approach for identifying, in a generic fashion, seismically risk-sensitive equipment. It is anticipated that the conclusions drawn therefrom and the methodology employed will, in part, reconcile some of the concerns dealing with the seismic qualification of equipment in operating plants. The approach taken augments an existing sensitivity analysis, based upon t… more

Date: January 1, 1982

Creator: Azarm, M. A.; Farahzad, P. & Boccio, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Annotated bibliography of safety-related occurrences in pressurized-water nuclear power plants as reported in 1975

The bibliography presented contains 100-word abstracts of reports to the U.S. Nuclear Regulatory Commission concerning operational events that occurred at pressurized-water reactor nuclear power plants in 1975. The report includes 1097 abstracts, arranged alphabetically by reactor name and then chronologically for each reactor, that describe incidents, failures, and design or construction deficiencies experienced at the facilities. Key-word and permuted-title indexes are provided to facilitate … more

Date: July 1, 1976

Creator: Scott, R. L. & Gallaher, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Annotated bibliography of safety-related occurrences in boiling-water nuclear power plants as reported in 1975

The bibliography presented contains 100-word abstracts of reports to the U.S. Nuclear Regulatory Commission concerning operational events that occurred at boiling-water reactor nuclear power plants in 1975. The report includes 1169 abstracts, arranged alphabetically by reactor name and then chronologically for each reactor, that describe incidents, failures, and design or construction deficiencies that were experienced at the facilities. Key-word and permuted-title indexes are provided to facil… more

Date: July 1, 1976

Creator: Scott, R. L. & Gallaher, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Digraph matrix analysis applications to systems interactions

Complex events such as Three Mile Island-2, Brown's Ferry-3 and Crystal River-3 have demonstrated that previously unidentified system interdependencies can be important to safety. A major aspect of these events was dependent faults (common cause/mode failures). The term systems interactions has been introduced by the Nuclear Regulatory Commission (NRC) to identify the concepts of spatial and functional coupling of systems which can lead to system interdependencies. Spatial coupling refers to de… more

Date: January 1, 1984

Creator: Alesso, H.P.; Altenbach, T.; Lappa, D.; Kimura, C.; Sacks, I.J.; Ashmore, B.C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department