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[en] The current controversy and uncertainty surrounding the disposal of low-level radioactive waste makes it ever more prudent to develop methods to minimize its generation in the first place. As the industry is challenged with active opposition, missed deadlines, and political challenges, Pacific Gas and Electric's Diablo Canyon nuclear station has implemented a plan to reduce waste generation from plant systems, from the modification and removal of plant equipment, and from the use of protective clothing and consumable contamination-control items. Our program has been extremely effective and may serve as a model for other nuclear power plants at a time of increasing processing and disposal costs. In 1994, for example, we were able to cut our radwaste generation in half-twice

[en] The purpose is to summarize estimates based on currently available data of the uncertainty associated with radiological assessment models. The models being examined herein are those recommended previously for use in breeder reactor assessments. Uncertainty estimates are presented for models of atmospheric and hydrologic transport, terrestrial and aquatic food-chain bioaccumulation, and internal and external dosimetry. Both long-term and short-term release conditions are discussed. The uncertainty estimates presented in this report indicate that, for many sites, generic models and representative parameter values may be used to calculate doses from annual average radionuclide releases when these calculated doses are on the order of one-tenth or less of a relevant dose limit. For short-term, accidental releases, especially those from breeder reactors located in sites dominated by complex terrain and/or coastal meteorology, the uncertainty in the dose calculations may be much larger than an order of magnitude. As a result, it may be necessary to incorporate site-specific information into the dose calculation under these circumstances to reduce this uncertainty. However, even using site-specific information, natural variability and the uncertainties in the dose conversion factor will likely result in an overall uncertainty of greater than an order of magnitude for predictions of dose or concentration in environmental media following shortterm releases

[en] The Diablo Canyon Power Plant is located on the Pacific coast near Avila Beach, California. The Pacific Gas and Electric Company owns and operates the two Westinghouse 1100 MWe PWR units. The commercial operation dates for units 1 and 2 were May 1985 and March 1986, respectively. A waste classification program has been established at Diablo Canyon to comply with federal regulations. Appendix F of 10 CFR 20 indicates the requirements for manifesting, certification, control, and tracking of low-level waste transferred to a land disposal site. Section 61.55 of 10 CFR 61 requires waste to be classified. Wastes suitable for land disposal must fall into one of three categories: class A, B, or C. Wastes are determined to fall into one of the three classes based on the concentration of particular radionuclides in the waste versus the limits set forth in tables 1 and 2 of section 61.55

[en] Some prominent new semi-inclusive DIS results from JLab and Hermes that have appeared since SPIN 2000 are presented. Polarized quark distributions have been extracted from the complete Hermes data set on H and D from 1996-2000, based on Monte Carlo 'purities'. The data quality permits for the first time the separation of the u-bar, d-bar and s + s-bar sea quark polarizations. Also, both laboratories have produced new single-spin asymmetries in the azimuthal distributions of semi-inclusive hadrons. New SSAs from longitudinally polarized proton and deuteron targets are presented, as well as beam-helicity SSAs from unpolarized protons

[en] Congress has enacted legislation specifying Yucca Mountain, Nevada, for characterization as the candidate site for the disposal of spent fuel and high-level wastes and has authorized a monitored retrievable storage (MRS) facility if one is warranted. Nevertheless, the exact configuration of the facilities making up the Federal Waste Management System (FWMS) was not specified. This has left the Office of Civilian Radioactive Waste Management (OCRWM) the responsibility for assuring the design of a safe and reliable disposal system. In order to assist in the analysis of potential configuration alternatives, operating strategies, and other factors for the FWMS and its various elements, a decision-support tool known as the systems integration operations/logistics model (SOLMOD) was developed. SOLMOD is a discrete event simulation model that emulates the movement and interaction of equipment and radioactive waste as it is processed through the FWMS - from pickup at reactor pools to emplacement. The model can be used to measure the impacts of different operating schedules and rules, system configurations, and equipment and other resource availabilities on the performance of processes comprising the FWMS and how these factors combine to determine overall system performance. SOLMOD can assist in identifying bottlenecks and can be used to assess capacity utilization of specific equipment and staff as well as overall system resilience

[en] A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research results, which were published in NUREGICR-6719 in July 2001, is presented in this paper

[en] A ⁵¹Cr release assay has been used to demonstrate that human polymorphonuclear leucocytes (PMNL) can damage herpes simplex infected target cells sensitized with antiviral antibody. Effective sensitizing antibodies were found in both serum and saliva of all those persons tested who were subject to recurrent cold sores. PMNL were much less effective as killer cells than peripheral blood mononuclear cells, but as they are the predominant inflammatory cell within the HSVl lesion they may be, quantitatively, more important. The cytotoxic effects of both PMNL and mononuclear cells were significantly reduced by prostaglandin El as well as by several drugs that were tested. It is suggested that antibody dependent PMNL-mediated cytotoxicity may play a role in the human host defences against recrudescent herpes simplex infection. (author)

[en] Sponsored by the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) is carrying out a research program to develop a technical basis to support the safety evaluation of deeply embedded and/or buried (DEB) structures as proposed for advanced reactor designs. In this program, the methods and computer programs established for the assessment of soil-structure interaction (SSI) effects for the current generation of light water reactors are evaluated to determine their applicability and adequacy in capturing the seismic behavior of DEB structures. This paper presents an assessment of the simplified vs. detailed methodologies for seismic analyses of DEB structures. In this assessment, a lump-mass beam model is used for the simplified approach and a finite element representation is employed for the detailed method. A typical containment structure embedded in a soil profile representative of a typical nuclear power plant site was utilized, considering various embedment depths from shallow to full burial. BNL used the CARES program for the simplified model and the SASSI2000 program for the detailed analyses. The calculated response spectra at the key locations of the DEB structure are used for the performance assessment of the applied methods for different depths of burial. Included in the paper are: (1) the description of both the simplified and detailed models for the SSI analyses of the DEB structure, (2) the comparison of the analysis results for the different depths of burial between the two methods, and (3) the performance assessment of the analysis methodologies for SSI analyses of DEB structures. The resulting assessment from this study has indicated that simplified methods may be capable of capturing the seismic response for much deeper embedded structures than would be normally allowed by the standard practice

[en] Motivated by many design considerations, several conceptual designs for advanced reactors have proposed that the entire reactor building and a significant portion of the steam generator building will be either partially or completely embedded below grade. For the analysis of seismic events, the soil-structure interaction (SSI) effect and passive earth pressure for these types of deeply embedded structures will have a significant influence on the predicted seismic response. Sponsored by the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) is carrying out a research program to assess the significance of these proposed design features for advanced reactors, and to evaluate the existing analytical methods to determine their applicability and adequacy in capturing the seismic behavior of the proposed designs. This paper summarizes a literature review performed by BNL to determine the state of knowledge and practice for seismic analyses of deeply embedded and/or buried (DEB) nuclear containment type structures. Included in the paper is BNL's review of the open literature of existing standards, tests, and practices that have been used in the design and analysis of DEB structures. The paper also provides BNL's evaluation of available codes and guidelines with respect to seismic design practice of DEB structures. Based on BNL's review, a discussion is provided to highlight the applicability of the existing technologies for seismic analyses of DEB structures and to identify gaps that may exist in knowledge and potential issues that may require better understanding and further research