| Question |
Answer |
| Seismic Concerns |
|
| Is the ISFSI designed to withstand earthquakes
without a release of radiation? |
Yes. The Indian Point ISFSI has been designed to satisfy
federally mandated requirements for structural characteristics
and resistance to seismic events occurring at the pad,
during handling of casks over the spent fuel pool and
en-route from the spent fuel pool to the storage pad.
|
| Should the casks be anchored together? |
No. The seismic profile of the Indian Point site does
not require anchoring the casks. There is at least one
site in California where casks will most likely be anchored,
however, the seismic profile is much different from New
York. |
| What is the design basis earthquake DBE for the ISFSI?
How does that differ from the operating basis earthquake
OBE? |
The DBE is defined as the largest earthquake which
can reasonably be expected to occur at the site, based
on the known seismicity of the area. IPEC safety systems
are designed to remain functional both during and after
this event, which measures 0.15g peak ground acceleration
on the Housner spectrum. The design basis earthquake
for the Indian Point region is roughly a Mercalli level
VII.
The Operating Basis Earthquake is a smaller earthquake
than the DBE. The OBE has a maximum horizontal peak
ground acceleration of 0.1g vs. 0.15g for the DBE. Plant
equipment is designed to remain functional during and
after the OBE. The following is the NRC definition from
Appendix S to Part 50: “The Operating Basis Earthquake
Ground Motion (OBE) is the vibratory ground motion for
which those features of the nuclear power plant necessary
for continued operation without undue risk to the health
and safety of the public will remain functional.” |
| How is seismic activity monitored? |
IPEC monitors seismic activity at the site using
seismic recorders located in the IP3 containment building.
The recorders are set to alarm in the IP3 control building
when seismic activity is recorded at a level well below
the operating basis earthquake. The Nuclear Regulatory
Commission Guide 1.12 – “Nuclear Power Plant
Instrumentation For Earthquakes”, provides further
details on seismic monitoring criteria. (/www.nrc.gov/reading-rm/doc-collections/reg-guides/power-reactors/active/01-012/)
Regulatory Guide 1.166, "Pre-Earthquake Planning
and Immediate Nuclear Power Plant Operator Post-Earthquake
Actions," provides criteria for plant shutdown
after an earthquake. (www.nrc.gov/reading-rm/doc-collections/reg-guides/power-reactors/active/01-166/) |
| Could rockslides cause the casks to fall over and roll
into the Hudson River? |
No. |
| |
|
| Criticality Prevention |
|
| Is it possible for the fuel to go critical in the dry
casks? |
Spent fuel transfer and storage systems are designed
to remain subcritical under all credible conditions. [10
CFR 72.124(a) and 72.236(c)] The absence of water (a neutron
moderator) in the dry cask storage system is the greatest
factor involved in preventing criticality. Additional
measures of safety include the use of a neutron absorber
throughout the walls of the multi-purpose canister MPC,
low enrichment (3-5%) of the fuel, the long decay time
since use for the fuel (at least 5 years), and the configuration
of the fuel. |
