Hazard categorization

These topics are the subject of DOE Standard DOE-STD-1027-92, "Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23 Nuclear Safety Analysis Reports," which provides guidance for facility managers and Cognizant Secretarial Offices (CSOs). They are also discussed in the DOE Standard DOE-STD-3009-94,... 

Table 1. Representative sample of chemical warfare agents capable of penetrating the skin (percutaneous hazards), categorized according to primary (local or systemic) effect ...

DOE O 5480.23 Nuclear Safety Analysis Reports For nuclear facilities only (Hazard Category 3 or above), requires preliminary and final hazard categorization and comprehensive hazard/safety analysis to support the conclusion that nuclear facility activities can be conducted without causing unacceptable health or safety impacts to workers, public, or environment. SAR prepared in accordance with DOE-STD-3009 or a BIO prepared in accordance with DOE-STD-3011. Annual updates to either SAR or BIO for those changes that affect the safety basis. Preliminary and final hazard categorization prepared in accordance with DOE-STD-1027. 

DOE-STD-1027-92, Hazard Categorization and Accident Analysis Techniques for Compliance with DOE 0 5480.23, Nuclear Safety Analysis Reports . 

Some preliminary guidance on the use of the graded approach is available in a DOE draft Standard on Hazard Categorization. Further guidance on the graded approach with regard to classifying safety class SSCs is under development. 

The facilities have been divided into multiple segments for final hazard categorization ... 

The generic approach to airborne release development was that approach used by DOE in developing the HC2 threshold quantity for each isotope as described in Attachment 1 of DOE-STD-1027-92, Change 1 (DOE, 1992). DOE developed a set of final release fraction values (FRFVs) for the various physical forms of materials that could be present in a facility. These FRFVs were used to reduce the quantity of radioisotope materials at risk for airborne release from the facility in an accident situation. The FRFVs were intended to address all of the uncertainties noted above on a facility wide basis. DOE noted that it was possible to calculate higher values for FRFVs for some physical forms and processes but that those processes were likely to be present on only a local and not a facility wide basis. Thus, DOE concluded the FRFVs were an adequate average for hazard categorization purposes. DOE used the FRFVs... 

U.S. Department of Energy (DOE), 1992b, Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports, DOE-STI5-1027-92, (Change Notice 1 September 1997), U.S. Department of Energy, Washington, D.C., December 1992. 

The Basis for Interim Operation (BIO) document for K>Reactor in Cold Standby and the L- and P-Reactor Disassembly Barins was pr ared in accordance vrith the draft DOB standard for BIO preparatiott (dated October 16, 1993). The actives for tte BIO preparation process included hamd iden carion, hazard categorization, and a preliminary hazards analysis. These actmties, along with the review of the K-Reactor Safety Anafysis R rt (SAR), K-, and P>Reactor Technical Spedfications (TS), K-Reactor Cold Standby Plan, L-Reactor ( Id Shutdown Plan, P-Reactor Standby Plait, and other safety documents, were used to compile the BIO. 

Hazards assessments for K-Reactor in Cold Standby have been performed to determine the overall hazard categorization (Ref. 8-2, 8-3, 8-4). Radiological hazards of consequence have been identified in the following K-Reactor major areas IMsassembly Basin, Purification Area, Assembly Area, and Moderator Storage Areas. The overall categorization is based on the. consequences of a postulated radionuclide and/or chemical rdease firom K-Reactor, as wdl as the potent for a criticality event... 

The criteria for detemuning the radiolo cal hazard categorization are provided In DOE-STD-1027-92 8-8) and the criteria for determining the chemical haa rd categorization are... 

The analysis conducted to determine the hazard categorization is performed without credit taken for engineered features or administrative controls. Examples of engineered features and administrative controls are those specific facility features (not including site location) such as building containment, stacks, equipmoit, systems, actions, or operating conditions, that are established to control risk. For chemical hazards, credit b to be taken for the existing location... 

Source BJC/OR-1112 Facility Hazard Categorization/Classification and Hazard Analysis Application Guide, Revision 4, January 2007 (32). Prepared for the U.S. Department of Energy. 

BJC/OR-1112, Facility hazard categorization/classification and hazard analysis application guide. Revision 4, January 2007. Prepared for the Department of Energy under Contract DE-AC05-980R22700 by the Bechtel Jacobs Company. 

DOE-STD-1027, Hazard categorization and accident analysis techniques for compliance 16 with DOE Order 5480.23, Nuclear safety analysis report. Document is available from Department of Energy, AD-631/FORS, Washington, DC. 

It must be noted that, according to a strict application of Ref. [1], there should always be five defence in depth levels and the need for systems at any defence in depth level should be defined in connection with the safety analysis of the plant and therefore with the safety classification of its structures, systems and components. However, many safety issues have to be considered at a research reactor, not always explicitly correlated with component failures, such as most of the items listed in Section 2.4, which are part of the hazard categorization of the facility. Therefore the recommended global approach tries to synthesize them and develop a comprehensive proposal. 

A prehminary screening of the external events to be considered in the design of a research reactor can be done on the basis of a detailed hazard categorization. For facilities in the lowest category (hazard category 3) some extreme scenarios (aircraft crash, blast loads, tornado) may be screened out either by virtue of the selection of the site or on the basis of a low probabihty of occurrence. 

To establish the final hazard categorization of facilities and safety, and hence of the performance and design classification of the structures, systems and components according to the radiological hazard posed to the environment, individuals and the population in the event of an unmitigated accident ... 

Bearing in mind the hazard categorization described in Section 3, the following distinctions apply for emergency procedures ... 

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