Agenda - 02-02-1999 - 9e1 - Laserfiche WebLink

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10 the entire period of the Harris operating license, will double if pools C and D are activated. If integrated over .the remaining period of the operating license, the probability will more than double. 42. The PWR racks in pools C and D will be safe against criticality for a compazatively narrow range of fuel enrichment and burnup. Thus, assuming that the general nature of fuel-movement continues as before, the probability of a criticality accident will be significantly increased if pools C and D are activated. This probability will increase on a per-movement basis, so it will more than double when integrated over the entire period of the Harris operating license. The consequences of a criticality accident may also be significantly increased. 43. Activation of pools C and D will add to the electrical load and CCW heat load of existing Harris systems. It will also add to the burden of work on the Harris operators. These effects will increase the probability of two categories of design-basis or severe accidents. First, they will sigmficantly increase the probability of accidents associated with the Harris reactor, because the reactor's CCW and electrical systems and its operators will be under greater stress. Second, they will significantly increase the probability of accidents at the Harris pools that are attributable to interruptions in cooling and electricity supply and to increased operator stress. Also, the inability of cooling piping at pools C and D to meet ASME code requirements could significantly increase the probability of design-basis or severe accidents at these pools. 44. As mentioned in paragraph 24 above, to my knowledge there has been no site-specific analysis of severe accidents affecting any of the Harris pools. To the extent that such accidents have been previously evaluated, their consequences will be significantly increased by the activation of pools C and D. The fuel storage capacity of these pools will roughly double the storage capacity at Harris, creating the potential for a doubled inventory of radioactivity. Severe accidents could affect some or all of the Harris pools. As I have discussed in pazagraph 30 above, the potential doubling of radioactivity in the pools could significantly increase the consequences of severe accidents. J. Possibility of New or Different Kinds of Accident from any Accident Previously Evaluated 45. To my knowledge, there has been no site-specific evaluation of the probability or consequences of severe accidents at pools A and B at Harris. A variety of severe accidents are possible and should be subjected to the kind of systematic analysis that is performed in an IPE and IPEEE. The NRC has performed evaluations of accidents involving loss of water from fuel pools, generically and for sites other than Harris. However, these evaluations are seriously deficient because they failed to consider partial uncovering of fuel. To summarize, at pools A and B there exists the possibility of new or different kinds of accident from any accident previously evaluated. The same possibility will exist at pools C and D if these are activated. 46. Provision of electrical power and CCW service from the existing Harris plant to pools C and D could introduce the potential for design-basis or severe accidents that aze new or different from any accident previously considered. The IPE and IPEEE studies performed for Harris did not address the provision of electrical power and CCW service to pools C and D. As an example of the potential for new or different accidents, the need to provide cooling to pools C and D will place increased stress on the CCW system and the plant operators during adesign-basis LOCA.