Core inventory

For Monsanto, the core inventory naturally led to an expanded corporate inventory which was placed into this new database. It now includes raw materials, supplies and a considerable list of other types of substances and physical agents encountered in the workplace. 

As an illustration. Table 9.2 shows core inventory and estimate of total release of radionuclides following the accident in April 1986 at the Chernobyl nuclear power station.The list of radionuclides and specific matrices which should secure an increased interest depends on the source of release and the localities of the site at which it occurs. In general the scenario is shown in Table 9.3. 

Core inventory and estimate of total release of radionuclides... 

Only two earlier reactor accidents caused significant releases or radionuclides the one at Windscale (United Kingdom) in October 1957 and the other at Three Mile Island (United States) in March 1979 (UNSCEAR-1982). While it is very difficult to estimate the fraction of the Windscale radionuclide core inventory that was released to the atmosphere, it has been estimated that the accident released twice the amount of noble gases that was released at Chernobyl, but 2,000 times less and Cs (DOE-1987). The Three Mile Island accident released approximately 2% as much noble gases and 0.00002% as much l as the Chernobyl accident. 

Phosgene was listed in the EEC Core Inventory (ECOIN) [602] as number... 

COF3 is included in the European inventory of existing chemical substances (EINECS) [602a], since it was inciuded in the core inventory [602] its EINECS number is 206-534-2. The U.S. DOT classifications are as foilows [1347] ... 

European Core Inventory (ECOIN), Volume IV, Commission of European Communities, Brussels (1981). 

To illustrate, we shall consider a 1000-MWe PWR with the same core composition and power density as the reactor described in Chap. 3. The in-core inventory of water is approximately 13,400 kg. The tritium produced by H(n, y) during one calendar year in an average thermal-neutron flux of 3.5 X 10 n/(cm -s) with an effective H(n, y) cross section of 3.35 X 10- b is... 

DjO in-core inventory to uranium inventory as in the Douglas Point Reactor, the yearly... 

Nuclide Half-life Release tot EBq % Core inventory tot EBq Contamination air (Bq m ground (kBq m" Stockholm Gavle area ... 

The EINECS Inventory, the European Inventory of Existing Chemical Substances, is an inventory of the chemical substances which were on the European Community market between January 1971 and September 1981. Substances which are not in the EINECS inventory are considered new and must pass a notification procedure before they can be marketed in the EC member states. The inventory has been compiled by the Commission of the European Communities (Directorate Gteneral IX, Environment, Consumer Protection and Nuclear Safety) in collaboration with the member states. The Commission first created a core inventory, ECOIN, with 33,000 substances based on... 

Staff from the ECDIN project participated in the creation of the core inventory, took care of the technical management of the reporting phase, and are still involved in support of translation and printing. The data flow between the member states, the Commission and CAS was controlled by an automatic system built in parallel to the proper ECDIN databank. The EINECS inventory has been implemented as a part of the ECDIN databank and ECDIN is the authoritative onfine version of EINECS. 

RADC (Ref. 9) A zero-dimensional, steady-state inventory code for calculating the overall plant mass balance for an abitrary number of radionuclides, including the total core inventory, the circulating inventory, the plateout inventory, and the He Purification System inventory. The current version of RADC contains a 250-nuclide library with the nuclear properties (decay constants, fission yields, etc.) from the 1978 compilation by Meek and Ryder. RADC has been used extensively to calculate the source terms that appear in Section 11.1 of previous HTGR PSARs and of the Standard MHTGR PSID. 

Recognized remanufacturing challenges include the procurement of used products, management of core inventory, quality of returned cores, product disassembly, processing/remanufacturing of components, assembly of remanufactured components, quality of remanufactured products, and appropriate pricing of remanufactured products. 

Radionuclide Half-life Core inventory (EBq) Total emission (EBq) % of inventory... 

After publication of the Rasmussen report (1975) and the TMI accident, the validity of the old and glorious TID was questioned, much research on the subject was carried out and, in 1992, after years of debate in all the scientific and regulatory centres all over the world, a NRC report was published (USNRC, 1992a) containing a new proposal of source term , which should replace the HD. The new proposed releases for a PWR are shown in Table 5-3, expressed as a fraction of core inventory. The releases for a BWR are slightly different. 

It is deemed realistic to ensure, by additional provisions of accident management, with a confidence limit of the order of 95 per cent, that the external iodine or caesium releases, in situations which otherwise would lead to uncontrolled severe accidents (core melt, and so on), be kept within the limit of the 0.1 per cent of the core inventory. 

Since model timescales were of the order of hundreds or thousands of years, any radionuclide in the core inventories with a half-life of a year or less was ignored. Any release rate less than 1 Bq-a was also eliminated from the output. 

Core inventory and estimate of total release of radionuclides from the accident of Chernobyl (IAEA 2006)... 

The Safety Injection System for core inventory control... 

There are, then, several potential sources of radioactive material to the containment atmosphere. The most important of these are thought to be gap release, in-vessel release, ex-vessel release, and late invessel release. A recent assessment of the magnitudes of these releases in terms of fractions of the initial core inventories of important radionuclides has been prepared [S-2]. Results of this assessment are shown in Tables II-2 and II-3. It is important to view the results shown in these tables as somewhat conservative examples of both the timing and the magnitude of radionuclide release. These examples are not prescriptions of accident sources to any particular reactor contaimnent. 

This document describes the treatment of reactor accident source terms used in the past for both the design and safety evaluation of many existing power plants. The document, which is now only of historical significance, envisages the important radionuclide releases to be the noble gases, iodine in gaseous form, and 1% of the initial core inventory of other radionuclides in particulate form. 

Such approaches, which aim at the establishment of a single quantity to represent the fraction of the core inventory that would be released in the event of a severe reactor accident, have now been widely abandoned. As has been summarily described by Malinauskas and Kress (1991), currently fission product release is recognized to be both scenario- and plant-specific, and it has become necessary to replace simple release fractions by computer codes that couple release and transport with thermal-hydraulic aspects. In particular it has been realized that the timing of fission product release can be of great importance and that the releases... 

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