| No. S-08-023
“Thoughts on Spent Fuel Storage”
Prepared Remarks for
The Honorable Gregory B. Jaczko
Commissioner
U.S. Nuclear Regulatory Commission
at the
Nuclear Energy Institute’s Dry Storage Information Forum
Bonita Springs, Florida
May 13, 2008
I am pleased to join you in Florida for this important
conference. You represent the members of the public, licensees,
vendors, and manufacturers and technical experts who will help
determine – along with regulators – the future of spent fuel storage
and transportation. The issues that you are addressing here this
week are important to public health and safety and they are also
integral to site operations at nuclear power plants. That is why it
is important for you to be here and I am pleased to be able to
participate and share some of my thoughts with you.
Before I go any further, I should mention that
I am one of four Commissioners of the NRC and the views I offer here
are my own – not necessarily the agency’s.
With that in mind, I would like to begin by offering some context
for our discussions. Currently, there are 65 operational power
reactor sites and under the agency’s license renewal program over
half the reactor units have either had or are currently undergoing a
license renewal review by NRC staff. Additionally, nine combined
license applications for 15 new reactor units have been submitted to
the agency for review that may, if they meet safety requirements and
are approved, potentially lead to new construction at primarily
existing sites.
As of February 2008 there are 34 operating generally licensed
Independent Spent Fuel Storage Installations (ISFSIs) and 15
specifically licensed ISFSIs at or away from reactor sites.
Currently, 16 sites are pursuing generally licensed ISFSIs, which
leave 19 sites that have not announced their intentions concerning
dry fuel storage. This amounts to 30 states having at least one
ISFSI.
Those statistics show that over the last half century licensees
have demonstrated spent fuel can be safely and securely managed
onsite at nuclear power plants. That, coupled with the fact that
long-term disposition of this material remains a challenge in the
United States, leads me to believe that the
focus should remain on shorter-term storage and any additional
safety and security improvements that can be made there.
The most clear-cut example of an area where additional safety
margins can be gained involves
additional efforts to move spent nuclear fuel from pools to dry cask
storage. I imagine I may be ‘preaching to the choir’ on this
point, as this is the dry storage information forum after all. The
risk at a nuclear power plant site is centered on the operating
plant, not the spent fuel stored in massive casks and passively
cooled in concrete bunkers. The
threat of terrorism is the one element which complicates the risk to
stored fuel. However, the
NRC is also formally addressing the security of dry cask storage
through a rulemaking the Commission ordered last December 2007.
The proposed rule to be developed by the staff will seek to codify
the protective measures in the Orders issued after September 11,
2001 and resolve regulatory differences between specifically and
generally licensed ISFSIs.
The staff’s proposal would set a
5 rem dose limit at the control area boundary for both acts of
radiological sabotage and for design basis events. The staff also
proposed establishing a 1 rem dose limit at the site boundary for
both events consistent with NRC’s 1995 ISFSI emergency planning
basis. I supported that proposal but the majority of the Commission
did not.
The staff is working on the technical basis for the rule and
plans to hold public meetings in Las Vegas, NV and Rockville, MD in
September 2008 that I would encourage everyone to participate in.
The staff then expects to complete the technical basis sometime this
summer and provide the Commission with a proposed rule by the summer
of 2009.
I also believe that the recent pilot probabilistic risk
assessment (PRA) developed by NRC provides additional supporting
evidence of the benefits of having more of the spent fuel held in
dry storage. The staff’s PRA was done to serve as a guide for
assessing the risk to the public and identifying the dominant
contributors to that risk which could be used for performing similar
PRAs in the future. Ultimately, the staff’s risk estimates of an
individual probability of a latent cancer fatality were negligibly
small in the first year of operation.
The largest contributor to risk was found to be the actual transfer
of the fuel from wet to dry storage prior to being placed on the pad.
The staff’s report also evaluated the risk of a latent cancer in the
subsequent years of operation to be so small it might as well have
been “zero.”
Therefore, in an effort to be ever vigilant about the safety of
spent fuel,
I believe the NRC should develop new regulations which require spent
fuel be moved to dry cask storage after it has been allowed to cool
for five years. This step, recognizing the inherent safety
benefits of dry storage and combining that knowledge with the new
ISFSI security regulations under development, will provide a safer
and more secure disposition for spent fuel in the short term.
I have spent a fair amount of time talking about the storage
issues important to this conference, so now let me take a few
minutes to discuss a transportation issue. I understand licensees’
interest in maximizing the number of fuel assemblies that can be
placed in fuel canisters for shipment – thereby decreasing costs and
minimizing the number of shipments required.
The current safety margin is established in part by the requirement
that licensees demonstrate no criticality event would occur ever if
the fuel were involved in a transportation accident and water (which
can act as a moderator for a nuclear fission reaction) were to enter
a fuel canister.
There are two approaches licensees could use to attempt to
demonstrate that the safety margin can be maintained even with more
dense canisters.
1.
Use probabilistic analyses that attempt to show the chances of an
accident that allow water to infiltrate the casks is so low it isn’t
worth considering; or
2.
Do the real technical work looking at the actual material
composition of spent fuel to demonstrate that even with more fuel
assemblies, water infiltration would not cause a criticality
accident.
The Commission recently affirmed the NRC staff’s decision that the
first approach was not acceptable.
Licensees seeking to put more fuel in transportation packages
are, therefore, going to have to do the sound science and provide
the NRC with technical data that clearly demonstrates adding more
assemblies does not degrade safety. Such an analysis would be based
on the actual physical properties of the fuel rather than
hypothetical assumptions about potential accident scenarios. In my
view, modifying existing regulations based on an improved
understanding of spent fuel composition would be the only way the
agency could proceed in a manner that is consistent with its public
health and safety mandate.
In conclusion, I believe that spent fuel can be safely and
securely managed at reactor sites for many years to come.
I also believe the agency’s approach to this issue could be enhanced
by a rulemaking to require spent fuel to be moved from pools to dry
storage, combined with the ISFSI security rulemaking currently
underway. As far as the issue of how densely transportation
casks are packed is concerned, licensees have an opportunity to
proactively submit technical data and analyses that demonstrate a
continued adequate safety margin.
My closing message would be to encourage all stakeholders to
continue to engage the agency on these important issues. This forum
is a good forum for that dialogue and I appreciate the opportunity
to be here with you today.
I would welcome any questions you may have. |
