Nrc updating plant safety requirements
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.Unit 1 became as wet as the owner’s damp assurances and the NRC’s soggy oversight efforts.
The design bases external flood was a Probable Maximum Hurricane (PMH) while the design bases internal flood was the postulated rupture of a 14-inch diameter low pressure safety injection system pipe.
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.
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.