On 12/06/21 the Santa Lucia Chapter of the Sierra Club and SLO Surfrider filed joint comments on the Diablo Canyon Power Plant (DCPP) application to the County of SLO for a decommissioning permit. The letter addresses issues that should be addressed in the Environmental Impact Report that will be prepared over the next several months. A pdf can be found here, and it is set forth in full below.


County of San Luis Obispo Planning & Building, Room 300 Attention: S. Strachan

976 Osos Street

San Luis Obispo, CA 93408

Re: Notice of Preparation for the preparation of an Environmental Impact Report for the DCPP Decommissioning Project.

Dear Ms. Strachan,

The Sierra Club is the nation’s oldest and largest grassroots environmental organization. The Santa Lucia Chapter represents the more than 2,000 members of the Sierra Club in San Luis Obispo County. Surfrider is a non-profit organization that works to protect our ocean, waves, and beaches for the enjoyment of all people through a powerful community-based network. We request that all scoping comments received on this project be forwarded to California Coastal Commission staff. According to the timeline presented by PG&E at the November DCEP meeting, the applicant intends to pursue a CDP concurrently with the decommissioning application to the County, and the CCC has jurisdiction under Coastal Act Section 30601.

Once Through Cooling (OTC) will be used to cool the SFP until the material is transferred to casks for storage.i It is not defined in the Project Description whether OTC will end by 2031 or in Phase 2, projected to end in 2039.ii Phase 1 is covered and mitigated under a project EIR; phase 2 is planned as a programmatic EIR with mitigation deferred until implementation in Phase 2. In either case, a waiver or new permit will need to be issued for OTC during Phase 1. Operation of OTC beyond the current permit, while necessary for the project, will require substantial mitigation. Mitigation measures must be imposed in the Phase 1 CDP process.

The EIR should review the permits and Conditions of Approval for DCPP received from the CCC to ensure that all Conditions of Approval (COAs) associated with the permits were fulfilled, including outstanding issues regarding conservation and trail COAs and terms of the permitting, e.g., ISFSI storage.iii While the ISFSI installation is a baseline condition, the permitting condition of approval was for temporary storage, hence the baseline condition is also perceived to be temporary. All indicators re-enforce the reality that on-site spent fuel storage will be permanent, and permanent storage violates the language and conditions of the original permit.

The ISFSI facility will experience a “change in intensity of use ” pursuant to Pub Res Code 30106,

thereby triggering the CDP requirement. In addition, Special Condition 2 of the 2004 ISFSI permit uses an even lower standard for requiring a new or amended permit when “changes not described in permit submittals” occur. The following changes, both separately and in the aggregate, meet both standards for requiring a new/amended CDP for the ISFSI:

  1. An increase in the term of expected use of the ISFSI from interim to indefinite and probably permanent.
  2. Demolition of the rest of the facility that generated the waste, which turns the ISFSI into a stand-alone facility with no necessity to be on its current site.
  3. Reduction of the security buffer zone from 12,000 acres to less than 100 acres, which would require significant new security structures and procedures.
  4. Commencement of commercial activities immediately outside of the new 100-acre facility, which will have employees without security clearances, also increasing security risks.
  5. An increase from 58 SNF storage cannisters to 138, which will max out and overcrowd the ISFSI, increasing various risks.
  6. A new generation of dry storage casks to be stored in the ISFSI are designed to withstand higher heat levels, which increases risks. The current ISFSI permit is based on the existing casks. A new permit is necessary to determine if the existing ISFSI is adequate for storage of the new casks.

The entire decommissioning is dependent on the ISFSI becoming the permanent onsite storage facility. Although it requires a separate permit, that permit should be considered either before or concurrently with the decommissioning. The fuel stored in the ISFSI will increase by 200% and an entirely new GTCC waste facility will be built to store radioactive equipment waste. The two facilities must be permitted for these future uses prior to the demolition, or there will be no place to put this waste. The Coastal Act requires submittal of related permits simultaneously.

PG&E plans to develop and install an SFPI, which is an independent cooling system for the Spent Fuel Pools that enables abandonment of the in-place plant systems supporting SFP cooling. A new separate permit should be required for the SFPI.

Given the need for ongoing monitoring of both the ISFSI and the GTCC Waste Storage Facility, an inspection, monitoring and reporting program similar to the one required for the SONGs decommissioning is appropriate. These requirements are found in Coastal Commission permit 9-19- 0194, Special Condition 3.3 Annual Reports, and Special Condition 7 Spill Prevention Control and Countermeasure Plan for the SONGS decommissioning. The County (for the GTCCWSF) and the CCC (for the ISFSI) should have the power to require inspection, maintenance, and annual reports. The Executive Director of the CCC and an appropriate officer of the County should have the power to require new or amended permits based on such reports.

The decommissioning process will require the permitting of a permanent storage facility on-site for GTCC waste material in appropriate casks.iv The DC ISFSI site-specific license SNM-2511 does not include GTCC waste material as part of the allowed contents of the DC ISFSI. Permanent storage of this highly radioactive material requires appropriate mitigation:

“Currently, there is no offsite facility licensed for disposal of GTCC waste, nor are there any federal disposal facilities licensed to receive GTCC waste. Therefore, all GTCC waste must be packaged and stored at the site at which the waste was generated.” However, the DC ISFSI site- specific license SNM-2511 does not include GTCC waste material as part of the allowed contents of the DC ISFSIv.”

New industrial facilities are generally not permitted under the same permit as a demolition permit. In addition, the NRC requires a site-specific waste handling permit for the GTCC facility. The ISFSI has its own separate permit; the GTCC waste facility should as well. Although the GTCC facility is not in the Coastal Zone, the County should follow the precedent established by the CCC of providing perpetual conservation and coastal access easements as mitigation for Diablo permits. The Project Description is clear that there are significant risks attendant to permanent or very long-term storage of highly radioactive material on site. These kinds of storage will require significant commensurate mitigation measures. We do not see a means for proper mitigation for such long-term impacts within Parcel P A requirement for offsite mitigation in the form of permanent and irrevocable conservation easements on the surrounding lands is appropriate.

We note:

Some segmentation waste may require onsite storage prior to disposal due to either activity levels or unexpected delays in transportation logistics. The materials classified as GTCC waste, will be loaded into storage containers and casks and transferred to the GTCC Waste Storage Facility for storage, remaining there until a licensed repository becomes available, another entity takes possession, or the U.S. Department of Energy (DOE) accepts the containers for offsite disposal. The remaining waste packages that may require on-site storage, including Class A, B and C waste, may also be placed for storage at the existing Old Steam Generator Storage Facility (OSGSF) or another existing onsite location. Storage would be for varying durations until such time that delays encountered during the transportation cycle have been resolved or radioactivity levels of the waste have been reduced to an acceptable level for offsite transportvi.

We do not see a means for proper mitigation for the long-term impacts as described above within Parcel

P. A requirement for offsite mitigation in the form of permanent and irrevocable conservation and access easements of North Ranch, Wild Cherry Canyon, and South Ranch are the only appropriate mitigation measures available. The Pecho Coast Trail should be extended along the coastal bluffs in South Ranch, Parcel P, and North Ranch to connect to the Pt. Buchon Trail. This will complete an essential link in the California Coastal Trail.

The Project Description anticipates that the County will be issuing certain ministerial permits, including grading permits, building permits, and demolition permits. The EIR should review impacts related to ministerial permits and mitigate possible impacts. Potential ministerial permits should be listed in the EIR for public review.

The EIR should review the impacts of these two project goals listed in 1.6. Project Objectives:

  • retain existing energy-infrastructure (e.g., switchyards, transmission lines, etc.) to meet customer needs;
  • create marine/harbor opportunities while protecting ecological resources through repurposing of the breakwater, Intake Structure, and associated harbor area.

Demolition projects unavoidably create impacts to air quality. While rigorous controls will be in place during the decommissioning including consultation with SLOAPCD tracking airborne asbestos, and other pollutants, the decommissioning of DCPP is a special circumstance with a potential for release of radiological particles. Several real time monitoring stations should be installed on site to detect airborne radiological particles. The data from the monitoring stations should be available for public review in real time. We have not seen any reference to monitoring radioactive particlesvii.

Section 2.3.3 Site Infrastructure Modifications lists several components deemed necessary for the decommissioning project. These modifications should be reviewed for impacts and possible redesign to alleviate negative impacts. We are particularly concerned about mitigating the impacts generated by new Concrete Batch Plants. There is extensive literature on the toxicity and environmental impacts of concrete operations, materials, and handling of concrete wash water from ready mix operations.

Stockpile areas should be reviewed and carefully sited, with particular attention paid to retaining any runoff from the stockpiled material in a rain event. Construction debris and contaminated soils could remain on site longer than anticipated if no depository is available. Soils and groundwater near stockpiles be monitored for migration of toxins from the piles.

Special review should be given to the engineering plan for the cofferdam and the restoration of the discharge structure area after demolition. Placement of riprap at the site has the potential for erosion of surrounding native cliff areasviii.

The Project Description lists numerous facilities that are anticipated to be recipients of waste generated by the decommissioning process, and the anticipated impacts from truck trips etc. The EIR should consider the impacts of using alternatives sites if those sites listed will not be available to receive the waste, and the impacts if the waste should have to be stored for longer periods on siteix.

Frequent rigorous monitoring and testing of fill materials engineered from crushed clean concrete and soils that will be used on site should be required.

The dismantling and segmentation of the most radioactive components of the facility will be done under water. We could not find a reference to how that water will be disposed of. Please include more information on this type of waste water disposalx.

Is the groundwater aquifer capable of producing 95 ac/y (26 million gallons) when the decommissioning is at peak water use in 2032 and beyond? If necessary, the EIR should include an analysis of where additional imported water will come from. The Project Description identifies various toxins present in the groundwater. We request that the EIR analyze what effect the groundwater pumping might have on the quality of the groundwater when decommission and restoration are completexi.

Thank you for this opportunity to comment, Sue Harvey, Conservation Chair

Sierra Club – Santa Lucia Chapter

P.O. Box 15755, San Luis Obispo, CA 93401 (805) 5343-8717

Jim Miers, Executive Committee

San Luis Obispo Chapter – Surfrider Foundation PO Box 13222


i. 2.3.6. Spent Fuel Island Installation/Auxiliary Saltwater System

The current configuration for SFP cooling utilizes the original once-through-cooling auxiliary saltwater system, component cooling water system, and the SFP cooling system. The existing once-through cooling- auxiliary saltwater cooling system will remain in place as the method for SFP cooling until all spent nuclear fuel is transferred to the ISFSI.

Spent Fuel Island Installation/Auxiliary Saltwater System

ii  1.3. Project Components … (2) Phase 2: Final Site Restoration (20352032 through 20422039) and Independent Spent Fuel Storage Installation (ISFSI) Only Operations. Phase 1 includes decontamination and dismantling of structures, systems, and components, transfer of spent fuel from the spent fuel pool (SFP) to the ISFSI, soil remediation associated with Phase 2 activities,Phase 1 – Pre-Planning and Decommissioning Project Activities (20254-203531) Spent Fuel Transfer to DC ISFSI

iii California Coastal Commission

In 1983, the CCC approved CDP No. A-4-82-593 for the Trainer/Simulator Building at the DCPP.

In 2004, the CCC approved CDP No. A-3-SLO-04-035 for the construction and operation in perpetuity of the ISFSI at the DCPP site.

In 2006, the CCC approved CDP No. E-06-011 and A-3-SLO-06-017 for the Steam Generator Replacement Project.

iv  2.3.19. Spent Nuclear Fuel and Greater Than Class C/Low-Level Radioactive Waste Management/Storage Table 2.1-1. Decommissioning Project Activities Summary


vi  2.3.12. Reactor Pressure Vessel and Internals Removal and Disposal vii Table 1.8-1. Anticipated Approvals and Authorizations for DCPP Decommissioning 

viii  2.3.17. Discharge Structure Restoration

ix  Table 2.3.20-1. Waste Transportation Trips Per Period; Table 2.3.20-2. Waste Transportation Tons Per Period; Disposal Sites

x  2.3.12. Reactor Pressure Vessel and Internals Removal and Disposal

xi Groundwater Remediation