ML071500033
| ML071500033 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 05/29/2007 |
| From: | NRC/OGC |
| To: | |
| SECY RAS | |
| References | |
| 72-26-ISFSI, RAS 13703 | |
| Download: ML071500033 (9) | |
Text
U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS DIVISION OF SPENT FUEL STORAGE AND TRANSPORTATION SUPPLEMENT TO THE ENVIRONMENTAL ASSESSMENT AND DRAFT FINDING OF NO SIGNIFICANT IMPACT RELATED TO THE CONSTRUCTION AND OPERATION OF THE DIABLO CANYON INDEPENDENT SPENT FUEL STORAGE INSTALLATION DOCKET NO. 72-26 PACIFIC GAS AND ELECTRIC COMPANY May 2007 1 SUPPLEMENT TO THE ENVIRONMENTAL ASSESSMENT AND DRAFT FINDING OF NO SIGNIFICANT IMPACT FOR THE DIABLO CANYON INDEPENDENT SPENT FUEL STORAGE INSTALLATION
1.0 INTRODUCTION
The staff of the U.S. Nuclear Regulatory Commission (NRC) has prepared this supplement to the Environmental Assessment (EA) and draft finding of no significant impact (FONSI) for the
Diablo Canyon Independent Spent Fuel Storage Installation (ISFSI), at the direction of the
Commission, in response to the June 2006 decision by the United States Court of Appeals for
the Ninth Circuit [
San Luis Obispo Mothers for Peace v. NRC , 449 F.3d 1016, 1028 (9 th Cir.2006)]. This supplement to the EA addresses the environmental impacts from potential terrorist acts directed at the Diablo Canyon ISFSI.
1.1 Description of the Proposed Action
By letter dated December 21, 2001, the Pacific Gas and Electric Company (PG&E) submitted an application to NRC, requesting a site-specific license to build and operate an ISFSI, to be
located on the site of the Diablo Canyon Power Plant, in San Luis Obispo County, California. In
accordance with the National Environmental Policy Act (NEPA), the NRC staff issued an EA for
this action on October 24, 2003, in conformance with NRC requirements specified in 10 CFR
51.21 and 51.30, and the associated guidance in NRC report NUREG-1748, "Environmental
Review Guidance for Licensing Actions Associated with NMSS Programs." The Commission
defines and EA in 10 CFR 51.14(a), as a concise public document that briefly provides sufficient
evidence and analysis for determining whether to prepare an environmental impact statement or a FONSI. A FONSI, in turn, is defined as a concise public document that briefly states the
reasons why an action will not have a significant effect on the human environment and therefore
does not require the preparation of an environmental impact statement [10 CFR 51.14(a)].
Based on the above EA, NRC also issued a FONSI for this action on October 24, 2003.
On March 22, 2004, the NRC staff issued Materials License No. SNM-2511 to PG&E, pursuant to 10 CFR Part 72, authorizing PG&E to receive, possess, store, and transfer spent nuclear fuel
and associated radioactive materials resulting from the operation of the Diablo Canyon Power
Plant (DCPP) in an ISFSI at the site for a term of 20 years. PG&E has begun construction of
the Diablo Canyon ISFSI and currently plans to start transferring spent fuel to the ISFSI in mid-
2008. 1.2 Purpose of this Supplement
In May 2002, during the NRC licensing review for the Diablo Canyon ISFSI, the San Luis Obispo Mothers for Peace (SLOMFP) and other citizens' groups petitioned NRC to hold a
hearing to address a number of contentions. One of these contentions argued that NRC must
consider terrorist acts in assessing the environmental impacts of the ISFSI, in order to comply
with NEPA. On December 2, 2002, NRC's Atomic Safety and Licensing Board (ASLB) denied
this contention and referred it to the Commission for review. On January 23, 2003, the
Commission affirmed the ASLB's denial of the terrorism contention.
2 After the March 2004 issuance of the Part 72 license for the Diablo Canyon ISFSI, SLOMFP and other parties filed a petition for review in the United States Court of Appeals for the Ninth
Circuit, asking that NRC be required to consider terrorist acts in its environmental review
associated with this licensing action. In its decision, dated June 2, 2006, San Luis Obispo Mothers for Peace v. NRC , 449 F.3d 1016, 1028 (9 th Cir. 2006), the Ninth Circuit held that NRC could not categorically refuse to consider the consequences of a terrorist attack under NEPA
and remanded the case to NRC.
In response to the Ninth Circuit decision, the Commission issued Memorandum and Order on February 26, 2007, directing the NRC staff to prepare a revised EA addressing the likelihood of
a terrorist attack at the Diablo Canyon ISFSI site and the potential consequences of such an
attack.1.3 Purpose and Need for the Proposed Action
The DCPP, owned and operated by PG&E, consists of two Westinghouse-type pressurized water reactor units, each rated at a nominal 1,100 Megawatts-electric; each unit has its own
spent fuel storage pool. The Diablo Canyon ISFSI is needed to provide additional spent fuel
storage capacity to ensure that the two DCPP units can continue to generate electricity beyond
the time when the storage capacity of the spent fuel pools is reached. The additional temporary
spent fuel storage capacity provided by the proposed ISFSI will enable PG&E to operate both
units until the current operating licenses expire (September 2021 for Unit 1, and April 2025 for
Unit 2).2.0
SUMMARY
On October 24, 2003, the NRC staff issued the EA and FONSI for the construction and operation of the Diablo Canyon ISFSI. 2.1Summary of Impacts Considered in the EA
In the EA, the NRC staff concluded that the construction, operation, and decommissioning of the Diablo Canyon ISFSI will not result in a si gnificant impact on the environment. In reaching this conclusion, the staff considered the impacts from normal operations and from postulated
accidents. The staff determined that construction impacts of the ISFSI will be minor, and limited
to the small area of the ISFSI site and the excavated-material disposal sites.
The staff also determined that there will be no significant radiological nor non-radiological environmental impacts from routine operation of the ISFSI. The ISFSI is a passive facility; no liquid or gaseous effluents will be released from the storage casks during normal operations.
The dose rates to members of the public during normal operations will be limited by the design
of the spent fuel storage casks, so that the cumulative dose to an offsite individual will be a
small fraction of the 100 millirem estimated annual dose received from naturally occurring terrestrial and cosmic radiation in the vicinity of the DCPP. The impacts from decommissioning
the ISFSI, which will not occur until the spent fuel is removed, were determined to be much less
than the minor impacts of construction and operation.
For hypothetical accidents, the calculated dose to an individual at the nearest site boundary was found to be well below the 5 rem limit for accidents set forth in 10 CFR 72.106(b) and in the U.S.
3 Environmental Protection Agency's protective action guidelines. The NRC staff did not consider the potential impacts of terrorist acts on the ISFSI in the initial EA.2.2Summary of Alternatives Considered in the EA
The alternatives PG&E considered, and the NRC staff addressed in its EA, included the shipment of spent fuel offsite, other methods to increase on-site spent fuel storage capacity, and the no-action alternative. In the first category, the alternatives of shipping spent fuel from
Diablo Canyon to a permanent Federal Repository, to a reprocessing facility, or to a privately owned spent fuel storage facility were determined to be non-viable alternatives, since no such
facilities are currently available in the United States, and shipping the spent fuel overseas is
impractical in light of the political, legal, and logistical uncertainties, and the high cost. Shipping
the DCPP spent fuel to another nuclear power plant was also determined to be a non-viable
alternative, because the receiving utility would have to be licensed to store the DCPP spent fuel, and it is unlikely that another utility would be willing to accept it, in light of its own limitations on
spent fuel storage capacity.
Other on-site storage alternatives PG&E considered included increasing the capacity of the existing spent fuel pools by reracking or spent fuel rod consolidation, or construction of a new
spent fuel storage pool. These alternatives were considered impractical, because of the high
costs associated with necessary plant modifications or new construction, coupled with the
significantly higher occupational exposures that would result from the extensive fuel-handling operations necessary to support these alternatives.
The no-action alternative could result in the extended or permanent shutdown of both DCPP units many years before the expiration date of their current operating licenses, once the current capacities of the units' spent fuel pools are reached. The electrical generation capacity lost
would most likely be replaced by fossil-fueled plants, which could result in greater
environmental impacts and higher costs for electricit
- y. In the short-term, the shutdown of the DCPP would have a negative impact on the local economy and infrastructure. For these
reasons, the no-action alternative was not considered a practical alternative.
In the EA, the Commission concluded that there are no significant environmental impacts associated with the proposed Diablo Canyon ISFSI, and other alternatives were not pursued
because of significantly higher costs, additional occupational exposures, and the unavailability
of off-site storage options. In this supplement to the EA, the NRC staff has considered potential
terrorist acts against the ISFSI, and after such consideration, has concluded that the
construction and operation of the ISFSI will not result in a significant effect on the human
environment.3.0NRC SECURITY REQUIREMENTS FOR ISFSIS
NRC has established requirements and has initiated several actions designed to provide high assurance that a terrorist attack would not lead to a significant radiological event at an ISFSI.
These include: (1) the continual evaluation of the threat environment by NRC, in coordination
with the intelligence and law enforcement communities, which provides, in part, the basis for the
protective measures currently required; (2) the protective measures that are in place to reduce
the chance of an attack that leads to a significant release of radiation; (3) the robust design of
dry cask storage systems, which provides substantial resistance to penetration; and (4) NRC 4 security assessments of the potential consequences of terrorist attacks against ISFSIs, that inform the decisions made regarding the types and le vel of protective measures. Over the past 20 years, there have been no known or suspected attempts to sabotage, or to steal, spent fuel
from spent fuel casks at ISFSIs, or to directly attack an ISFSI. Nevertheless, NRC is continually
reevaluating the threat environment, to determine w hether any specific threat to ISFSIs exists.3.1General Security Considerations
In response to terrorist attacks in New York and Washington, DC, on September 11, 2001, and to intelligence information subsequently obtained, the U.S. government initiated nation-wide
measures to reduce the threat of terrorism. These measures included numerous security
enhancements to prevent terrorists from gaining control of commercial aircraft, such as: (1) more
stringent screening of airline passengers and baggage by the Transportation Security
Administration; (2) the increased presence of Federal air marshals on many flights; (3) improved
training of flight crews; and (4) hardening of aircraft cockpits. Additional measures have been
imposed on foreign passenger carriers and domestic and foreign cargo carriers, as well as charter
aircraft. Beyond these measures directed at reducing the potential for terrorists to gain control of
an aircraft, the Federal government has greatly im proved the sharing of intelligence information and the coordination of response actions among Federal, State, and local agencies. NRC has
been an active participant in these efforts; it now has regular and frequent communications with
other Federal, State, and local government agencies and industry representatives, to discuss and
evaluate the current threat environment, to assess the adequacy of security measures implemented at licensed facilities, and, when necessary, to recommend additional actions.
NRC expanded its existing Threat Advisory System after the September 11, 2001, terrorist attacks, to include a broader range of licensees, including ISFSI licensees. NRC has
incorporated the threat condition levels used in the Department of Homeland Security's
Homeland Security Advisory System into it s own Threat Advisory System. The NRC threat assessment staff reviews, analyzes, coordinates, and disseminates threat and intelligence
information relevant to its licensees, at both strategic and tactical levels. The threat assessment
staff also serves as NRC's liaison and coordination staff with other organizations and agencies, including the intelligence and law enforcement communities. Through these improved
coordination and communication functions, NRC is able to efficiently develop and transmit
advisories to the appropriate licensees, who are then able to take prompt action. Thus, the
broad actions taken by the Federal government and the specific actions taken by NRC since
September 11, 2001, have helped to reduce the potential for terrorist attacks against NRC-
regulated facilities.3.2Requirements for ISFSIs
NRC has historically considered the potential impacts of terrorist acts in the development and implementation of its 10 CFR Part 73 security requirements. NRC's strategy for protecting
public health and safety and the environment focuses on ensuring that its safety and security
requirements, as implemented by licensees, in combination with the design features of dry cask
storage systems, are effective in protecting against successful terrorist attacks on ISFSIs.
NRC security requirements for ISFSIs are directed at assuring that terrorists cannot successfully carry out an attack against an ISFSI. These requirements, which apply to on-site security 5 measures, are part of a multi-layered Federal security strategy that also consists of on-going threat assessment, in coordination with other Federal agencies, and measures to identify and
preempt potential terrorist attacks. NRC reviews and approves facility security plans, in
evaluating the adequacy of these on-site measures. As part of the licensing review for the
Diablo Canyon ISFSI, the NRC staff evaluated and approved revisions to the Diablo Canyon site security plan that incorporated features of the proposed ISFSI. In that review, transmitted
by letter dated February 4, 2004, the NRC staff determined that the proposed security plan
revisions and facility design features met the requirements of Part 73, "Physical Protection of
Plants and Materials," which were the same requirements for ISFSIs that were in effect before
September 11, 2001. The details of specific security measures for each facility are designated
as Safeguards Information, in accordance with Section 147 of the Atomic Energy Act and 10
CFR 73.21, and, for that reason, cannot be released to the public. However, key features of the
security programs for ISFSIs include: (1) physi cal barriers; (2) surveillance; (3) intrusion detection; (4) a response to intrusions; and (5) offsite assistance from local law enforcement
agencies, as necessary.
After the September 11 terrorist attacks, the Commission initiated prompt and comprehensive actions to address both immediate and longer-term security measures for NRC-regulated
facilities. In the months immediately after the attacks, the Commission issued numerous
safeguards and threat advisories to its licensees, to strengthen licensees' capabilities and
readiness to respond to a potential attack on a nuclear facility. As part of the longer-term
efforts, NRC conducted a comprehensive review of the Agency's security program. This review
examined specific threats, such as a land-based vehicle bomb, ground assault with the use of
an insider, and water-borne assaults, which have led to the imposition of additional
requirements, through orders and rules, affecting many categories of licensees, including
ISFSIs. On October 16, 2002, the Commission issued orders to all licensees of operating ISFSIs to make mandatory the voluntary actions taken by those licensees in response to the
Commission's advisories, and to implement additional security enhancements identified in
NRC's ongoing comprehensive review of its safeguards and security programs and
requirements. This same order, imposing additional security measures, was issued to PG&E, for the Diablo Canyon ISFSI, on May 5, 2005. These measures, which are to be fully
implemented before the initial movement of spent fuel to the ISFSI, include: (1) increased
security patrols; (2) augmented security forces and weapons; (3) additional security posts; (4)
heightened coordination with local law enforcement and military authorities; (5) enhanced
screening of personnel; and (6) additional limitations on vehicular access. Collectively, these
measures further reduce the already low probability of a successful terrorist attack on an ISFSI, by establishing a substantial deterrent to an attack; by providing high assurance that an
attempted attack could be detected and effectively resisted; and by mitigating the extent of
damage and the potential radiological consequences if an attack were successful.
Based on its ongoing consideration of safeguards and security requirements, its review of information provided by the intelligence co mmunity, and the implementation of additional security measures at the Nation's ISFSIs, the Commission has high assurance that public
health and safety and the environment, and the common defense and security, continue to be
adequately protected in the current threat environment. 4.0CONSIDERATION OF ENVIRONMENTAL (RADIOLOGICAL) IMPACTS FROM 6 TERRORIST ACTS The NRC staff has considered the potential radiological impacts of terrorist acts on spent fuel storage casks, even though the staff considers the probability of a malevolent act against an
ISFSI that results in a significant radiological event to be very low. By design, dry cask storage
systems are highly resistant to penetration. To be licensed or certified by NRC, these systems must meet stringent requirements for structural, thermal, shielding, and criticality performance, and confinement integrity, for normal and accident events. Consequently, spent fuel storage
casks are extremely robust structures, specifically designed to withstand severe accidents, including the impact of a tornado-generated missile such as a 4000-pound automobile at 126
miles per hour. For the Diablo Canyon ISFSI, these design features include the massive HI-
STORM 100SA storage casks, which are made of inner and outer cylindrical carbon steel
shells, filled with 30 inches of concrete, and weighing up to 170 tons when fully loaded with
spent fuel. Each cask surrounds an internal multi-purpose canister, which safely confines the
spent fuel in a completely sealed, welded stainless steel cylinder. The spent fuel is further
protected by the metallic zircaloy cladding surrounding the fuel pellets in each fuel rod of a
spent fuel assembly. Finally, the nuclear fuel itself is in the form of solid ceramic pellets of
uranium dioxide; this means that a large amount of the radioactive material would remain in
solid form and not be dispersed beyond the immediate vicinity of the ISFSI, even if a terrorist act were successful in breaching the multiple layers of protection. Also, the location and low profile
of the ISFSI make it a difficult target for a large commercial airliner. Based on these facts, NRC
has determined that the current design features and additional security measures in place
provide high assurance that the spent fuel stored in an ISFSI is adequately protected.
Because of the uncertainty inherent in assessing the likelihood of a terrorist attack, NRC recognizes that, under general credible threat conditions, although the probability of such an
attack is believed to be low, it cannot be reliably quantified. NRC has adopted an approach that
focuses on ensuring that the safety and security requirements, and other security measures, are adequate and effective in countering and mitigating the effects of terrorist attacks against dry
cask storage systems. To provide high assurance t hat a terrorist act will not lead to significant radiological consequences, NRC has analyzed plausible threat scenarios and required
enhanced security measures to protect against the threats, and has developed emergency
planning requirements, which could mitigate potential consequences for certain scenarios. As
stated above, all these actions have been taken without regard to the probability of an attack.
This protective strategy reduces the risk from a terrorist attack to an acceptable level.
Following issuance of the 2002 security orders for ISFSIs, NRC used a security assessment framework as a screening and assessment tool, to determine whether additional security
measures, beyond those required by regulation and the security orders, were warranted for
NRC-regulated facilities, including ISFSIs. Initially, NRC screened threat scenarios to determine
plausibility. For those scenarios deemed plausible, NRC assessed the attractiveness of the
facility to attack by taking into account factors such as iconic value, complexity of planning
required, resources needed, execution risk, and public protective measures. In addition, NRC
made conservative assessments of consequences, to assess the potential for early fatalities
from radiological impacts. NRC then looked at the combined effect of the
attractiveness and the consequence analyses, to determine whether additional security
measures for ISFSIs were necessary.
In conducting the security assessments for ISFSIs, NRC chose several spent fuel storage cask 7 designs that were representative of most currently NRC-certified designs. Plausible threat scenarios considered in the generic security assessments for ISFSIs included a large aircraft
impact similar in magnitude to the attacks of September 11, 2001, and ground assaults using
expanded adversary characteristics consistent with the design basis threat for radiological
sabotage for nuclear power plants. The resulting generic assessments formed the basis for
NRC's conclusion that there was no need for further security measures at ISFSIs beyond those
currently required by regulation and imposed by orders issued after September 11, 2001.
The NRC staff reviewed the analyses done for the ISFSI security assessments, and compared
the assumptions used in these generic assessments to the relevant features of the Diablo
Canyon ISFSI. Based on this comparison, the staff determined that the assumptions used in
these generic security assessments, regarding the storage cask design, the source term (amount of radioactive material released), and the atmospheric dispersion, were representative, and in some cases, conservative, relative to the actual conditions at the Diablo Canyon ISFSI.
In fact, because of the specific characteristics of the spent fuel authorized for storage at the
Diablo Canyon ISFSI (lower burnup fuel), and the greater degree of dispersion of airborne
radioactive material likely to occur at the site, any dose to affected residents nearest to the
Diablo Canyon site will tend to be much lower than the doses calculated for the generic
assessments. Based on these considerations, the dose to the nearest affected resident, from
even the most severe plausible threat scenarios - the ground assault and aircraft impact
scenarios discussed above - would likely be below 5 rem. In many scenarios, the hypothetical dose to an individual in the affected population could be substantially less than 5 rem, or none
at all. In some situations, emergency planning actions could provide an additional measure of
protection to help mitigate the consequences, in the unlikely event that an attack were
attempted at the Diablo Canyon ISFSI.
5.0 AGENCIES AND PERSONS CONSULTED
No additional discussions or consultations with outside agencies or persons have been conducted in the development of this draft supplement to the EA. Comments submitted in
response to the issuance of this draft supplement will be considered by the NRC staff in
preparation of the final supplement to the EA.
6.0 CONCLUSION
The NRC staff concludes that the construction, operation, and decommissioning of the Diablo Canyon ISFSI, even when potential terrorist attacks on the facility are considered, will not result
in a significant effect on the human environmen
- t. NRC security requirements, imposed through regulations and orders, and implemented through the licensee's security plans, in combination
with the design requirements for dry cask storage systems, provide adequate protection against
successful terrorist attacks on ISFSIs. Therefore, a terrorist attack that would result in a
significant release of radiation affecting the public is not reasonably expected to occur.
7.0 DRAFT FINDING OF NO SIGNIFICANT IMPACT
The environmental impacts of the proposed action, namely, the approval of a site-specific license to build and operate an ISFSI, to be located on the site of the DCPP, in San Luis Obispo
County, California, have been reviewed in accordance with the requirements of 10 CFR Part 51.
As set forth in the Supplement to the Environm ental Assessment above (which this draft finding 8 incorporates by reference), NRC has considered the potential for terrorist attacks on the facility, and has determined that the storage of spent nuclear fuel at the Diablo Canyon ISFSI will not
have a significant effect on the quality of the human environment, based on the facility design
features and the mitigative security measures incorporated as part of the NRC licensing action
and in response to NRC security orders. These design features and mitigative security
measures will provide high assurance that s ubstantial environmental impacts will be avoided and thereby reduced to a non-significant risk level. Therefore, in accordance with 10 CFR
51.33, NRC issues this draft FONSI.
A Notice of availability of this supplement to the EA and draft FONSI will be published in the Federal Register. The Federal Register notice will include a request for comments on the proposed action and on the draft finding within thirty (30) days of publication. Pursuant to 10
CFR 51.33(e), a final determination to prepare an environmental impact statement or a final
FONSI for the proposed action shall not be made until the last day of the public comment period
has expired.
Documents related to this action, including the Diablo Canyon ISFSI EA and FONSI, and the Diablo Canyon ISFSI license, are available elec tronically at NRC's Electronic Reading Room at http://www.nrc.gov/reading-rm/adams.html. From this site, you can access NRC's Agencywide Document Access and Management System (ADAMS
), which provides text and image files of NRC's public documents. The ADAMS accession number for the Diablo Canyon ISFSI EA is ML032970337, and for the ISFSI license and related documents, the number is ML040780107.
If you do not have access to ADAMS, or if there are problems in accessing the documents located in ADAMS, contact NRC's Public Document Room (PDR) Reference staff at
1-800-397-4209, 301-415-4737, or by e-mail, to pdr@nrc.gov. These documents may also be viewed electronically on the public computers located at NRC's PDR, O1-F21, One White Flint
North, 11555 Rockville Pike, Rockville, MD 20852. The PDR reproduction contractor will copy
documents for a fee.
8.0 REFERENCES
1.U.S. Nuclear Regulatory Commission. Environmental Assessment and Finding of NoSignificant Impact Related to the Construction and Operation of the Diablo Canyon Independent Spent Fuel Storage Installation (TAC NO.L23399
). October 24, 2003.
NRC ADAMS Accession No. ML032970337.2. U.S. Nuclear Regulatory Commission.
Issuance of Materials License No. SNM-2511 for the Diablo Canyon Independent Spent Fuel Storage Installation (TAC NO.L23399
). March 22, 2004. NRC ADAMS Accession No. ML040780107.3.Diablo Canyon Independent Spent Fuel Storage Installation License Application -
Environmental Report, PG&E. December 2001 and Amendment 1, October 2002. NRC
ADAMS Accession Nos. ML020180196, ML020180173, and ML022950304 (p.150-186).