Nrc updating plant safety requirements
The analyses summarized in the UFSAR reported the flooding rates, flooding depths needed to submerge and disable safety components, alarms alerting workers to the flooding situation, and response actions and associated times for workers to intervene and successfully mitigate a flooding event.
In December 1993, the owner submitted an Individual Plant Examination (IPE) of St.
Lucie nuclear plant located about miles southeast of Ft. Federal regulations adopted more than five years earlier required the plant to be protected against natural phenomena.
The Atomic Energy Commission (AEC), forerunner to today’s Nuclear Regulatory Commission (NRC), issued guidance in August 1973 that explicitly informed nuclear plant owners and applicants that the natural phenomena to be protected against included heavy local precipitation.
On March 12, 2012, the NRC ordered the owners of all operating U. nuclear plants to undertake more comprehensive flooding and earthquake walkdowns and re-assessments. Lucie submitted its flooding walkdown report to the NRC on November 27, 2012.
The owner stated that “The flooding walkdowns verified that permanent structures, systems, components (SSCs), portable flood mitigation equipment, and the procedures needed to install and or operate them during a flood are acceptable and capable of performing their design function as credited in the current licensing basis” with but one exception—some missing and degraded conduit seals were found in electrical manholes connected to the reactor auxiliary buildings on Unit 1 and Unit 2.
INL supported Brookhaven National Lab (BNL) to update the detailed HFE review criteria contained in NUREG-0711 and NUREG-0700 based on (1) feedback obtained from end users, (2) the results of NRC research and development efforts supporting the NRC staff’s HFE safety reviews, and (3) other material the project staff identifymore » as applicable to the update effort.
INL submitted comments on development plans and sections of NUREGs 0800, 0711, and 0700.
Although the Pacific Ocean was literally a stone’s throw away, the complete loss of electrical power left workers unable to supply cooling water to the reactor cores of the three units that had been operating at the time; all three cores overheated and melted.
At full power, the plants produce 2,100 megawatts of electricity, enough for 1.5 million average homes.