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Book PROBABILISTIC SAFETY ASSESSMENT OF OPERATIONAL ACCIDENTS AT THE WASTE ISOLATION PILOT PLANT

Download or read book PROBABILISTIC SAFETY ASSESSMENT OF OPERATIONAL ACCIDENTS AT THE WASTE ISOLATION PILOT PLANT written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a probabilistic safety assessment of radioactive doses as consequences from accident scenarios to complement the deterministic assessment presented in the Waste Isolation Pilot Plant (WIPP) Safety Analysis Report (SAR). The International Council of Radiation Protection (ICRP) recommends both assessments be conducted to ensure that ''an adequate level of safety has been achieved and that no major contributors to risk are overlooked'' (ICRP 1993). To that end, the probabilistic assessment for the WIPP accident scenarios addresses the wide range of assumptions, e.g. the range of values representing the radioactive source of an accident, that could possibly have been overlooked by the SAR. Routine releases of radionuclides from the WIPP repository to the environment during the waste emplacement operations are expected to be essentially zero. In contrast, potential accidental releases from postulated accident scenarios during waste handling and emplacement could be substantial, which necessitates the need for radiological air monitoring and confinement barriers (DOE 1999). The WIPP Safety Analysis Report (SAR) calculated doses from accidental releases to the on-site (at 100 m from the source) and off-site (at the Exclusive Use Boundary and Site Boundary) public by a deterministic approach. This approach, as demonstrated in the SAR, uses single-point values of key parameters to assess the 50-year, whole-body committed effective dose equivalent (CEDE). The basic assumptions used in the SAR to formulate the CEDE are retained for this report's probabilistic assessment. However, for the probabilistic assessment, single-point parameter values were replaced with probability density functions (PDF) and were sampled over an expected range. Monte Carlo simulations were run, in which 10,000 iterations were performed by randomly selecting one value for each parameter and calculating the dose. Statistical information was then derived from the 10,000 iteration batch, which included 5%, 50%, and 95% dose likelihood, and the sensitivity of each assumption to the calculated doses. As one would intuitively expect, the doses from the probabilistic assessment for most scenarios were found to be much less than the deterministic assessment. The lower dose of the probabilistic assessment can be attributed to a ''smearing'' of values from the high and low end of the PDF spectrum of the various input parameters. The analysis also found a potential weakness in the deterministic analysis used in the SAR, a detail on drum loading was not taken into consideration. Waste emplacement operations thus far have handled drums from each shipment as a single unit, i.e. drums from each shipment are kept together. Shipments typically come from a single waste stream, and therefore the curie loading of each drum can be considered nearly identical to that of its neighbor. Calculations show that if there are large numbers of drums used in the accident scenario assessment, e.g. 28 drums in the waste hoist failure scenario (CH5), then the probabilistic dose assessment calculations will diverge from the deterministically determined doses. As it is currently calculated, the deterministic dose assessment assumes one drum loaded to the maximum allowable (80 PE-Ci), and the remaining are 10% of the maximum. The effective average of drum curie content is therefore less in the deterministic assessment than the probabilistic assessment for a large number of drums. EEG recommends that the WIPP SAR calculations be revisited and updated to include a probabilistic safety assessment.

Book Improving Operations and Long Term Safety of the Waste Isolation Pilot Plant

Download or read book Improving Operations and Long Term Safety of the Waste Isolation Pilot Plant written by National Research Council and published by National Academies Press. This book was released on 2001-06-11 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Waste Isolation Pilot Plant (WIPP) is a deep underground mined facility for the disposal of transuranic waste resulting from the nation's defense program. Transuranic waste is defined as waste contaminated with transuranic radionuclides with half-life greater than 20 years and activity greater than 100 nanocuries per gram. The waste mainly consists of contaminated protective clothing, rags, old tools and equipment, pieces of dismantled buildings, chemical residues, and scrap materials. The total activity of the waste expected to be disposed at the WIPP is estimated to be approximately 7 million curies, including 12,900 kilograms of plutonium distributed throughout the waste in very dilute form. The WIPP is located near the community of Carlsbad, in southeastern New Mexico. The geological setting is a 600-meter thick, 250 million-year-old saltbed, the Salado Formation, lying 660 meters below the surface. The National Research Council (NRC) has been providing the U.S. Department of Energy (DOE) scientific and technical evaluations of the WIPP since 1978. The committee's task is twofold: (1) to identify technical issues that can be addressed to enhance confidence in the safe and long-term performance of the repository and (2) to identify opportunities for improving the National Transuranic (TRU) Program for waste management, especially with regard to the safety of workers and the public. This is the first full NRC report issued following the certification of the facility by the U.S. Environmental Protection Agency (EPA) on May 18, 1998. An interim report was issued by the committee in April 2000 and is reproduced in this report. The main findings and recommendations from the interim report have been incorporated into the body of this report. The overarching finding and recommendation of this report is that the activity that would best enhance confidence in the safe and long-term performance of the repository is to monitor critical performance parameters during the long pre-closure phase of repository operations (35 to possibly 100 years). Indeed, in the first 50 to 100 years the rates of important processes such as salt creep, brine inflow (if any), and microbial activity are predicted to be the highest and will be less significant later. The committee recommends that the results of the on-site monitoring program be used to improve the performance assessment for recertification purposes. These results will determine whether the need for a new performance assessment is warranted. For the National TRU Program, the committee finds that the DOE is implementing many of the recommendations of its interim report. It is important that the DOE continue its efforts to improve the packaging, characterization, and transportation of the transuranic waste.

Book Probabilistic Safety Assessment in the Chemical and Nuclear Industries

Download or read book Probabilistic Safety Assessment in the Chemical and Nuclear Industries written by Ralph Fullwood and published by Butterworth-Heinemann. This book was released on 2000 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: In addition to presenting methodology, it shows how to identify accident vulnerability in the two industries. It reviews the causes of the two major nuclear accidents and many fatal accidents in the chemical industry, including Bhopal. Many examples of applications of PSA to both industries are presented."--BOOK JACKET. "Problems are included at the end of many chapters with answers at the back of the book."--Jacket.

Book Waste Isolation Pilot Plant Construction

Download or read book Waste Isolation Pilot Plant Construction written by and published by . This book was released on 1980 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Analysis of the Annual Probability of Failure of the Waste Hoist Brake System at the Waste Isolation Pilot Plant WIPP

Download or read book An Analysis of the Annual Probability of Failure of the Waste Hoist Brake System at the Waste Isolation Pilot Plant WIPP written by and published by . This book was released on 1995 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Environmental Evaluation Group (EEG) previously analyzed the probability of a catastrophic accident in the waste hoist of the Waste Isolation Pilot Plant (WIPP) and published the results in Greenfield (1990; EEG-44) and Greenfield and Sargent (1993; EEG-53). The most significant safety element in the waste hoist is the hydraulic brake system, whose possible failure was identified in these studies as the most important contributor in accident scenarios. Westinghouse Electric Corporation, Waste Isolation Division has calculated the probability of an accident involving the brake system based on studies utilizing extensive fault tree analyses. This analysis conducted for the U.S. Department of Energy (DOE) used point estimates to describe the probability of failure and includes failure rates for the various components comprising the brake system. An additional controlling factor in the DOE calculations is the mode of operation of the brake system. This factor enters for the following reason. The basic failure rate per annum of any individual element is called the Event Probability (EP), and is expressed as the probability of failure per annum. The EP in turn is the product of two factors. One is the {open_quotes}reported{close_quotes} failure rate, usually expressed as the probability of failure per hour and the other is the expected number of hours that the element is in use, called the {open_quotes}mission time{close_quotes}. In many instances the {open_quotes}mission time{close_quotes} will be the number of operating hours of the brake system per annum. However since the operation of the waste hoist system includes regular {open_quotes}reoperational check{close_quotes} tests, the {open_quotes}mission time{close_quotes} for standby components is reduced in accordance with the specifics of the operational time table.

Book Safety Evaluation Report of the Waste Isolation Pilot Plant Contact Handled CH Waste Documented Safety Analysis

Download or read book Safety Evaluation Report of the Waste Isolation Pilot Plant Contact Handled CH Waste Documented Safety Analysis written by and published by . This book was released on 2005 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Safety Evaluation Report (SER) documents the Department of Energy's (DOE's) review of Revision 9 of the Waste Isolation Pilot Plant Contact Handled (CH) Waste Documented Safety Analysis, DOE/WIPP-95-2065 (WIPP CH DSA), and provides the DOE Approval Authority with the basis for approving the document. It concludes that the safety basis documented in the WIPP CH DSA is comprehensive, correct, and commensurate with hazards associated with CH waste disposal operations. The WIPP CH DSA and associated technical safety requirements (TSRs) were developed in accordance with 10 CFR 830, Nuclear Safety Management, and DOE-STD-3009-94, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Safety Analysis Reports.

Book Radioactive Waste Management

Download or read book Radioactive Waste Management written by and published by . This book was released on 1981 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Energy Research Abstracts

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Energy and water development appropriations for 1989

Download or read book Energy and water development appropriations for 1989 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 1988 with total page 1740 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Energy and Water Development Appropriations for 1989 Department of Energy FY 1989 budget justifications

Download or read book Energy and Water Development Appropriations for 1989 Department of Energy FY 1989 budget justifications written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 1988 with total page 1700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Energy and Water Development Appropriations for 1991

Download or read book Energy and Water Development Appropriations for 1991 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 1990 with total page 1484 pages. Available in PDF, EPUB and Kindle. Book excerpt: