Responses to Questions from the Public for the Nov. 29, 2018 CEP Meeting
Ground Rules for Questions:
- SCE will only answer questions that are directed to SCE; we will forward questions directed to the Nuclear Regulatory Commission (NRC) or others
- SCE will not reply to general comments
- Names of the submitter will be provided with the question and identified by full first name and last name initial
- Similar questions will be combined, along with the names of the submitters
- Multi-faceted questions may be separated into individual answers
- SCE reserves the right to restate submitted questions for clarity; a full list of un-redacted questions is provided here
- The term “Answer Pending” is used when information is not yet available
Will the NRC require Holtec to recall the canisters because of potential scratching incurred during the downloads. (Caroline K.)
This question has been referred to the NRC.
What you should know: The canisters at SONGS are fabricated using corrosion-resistant 316L stainless steel. The inert oxide film designed to protect the canister from corrosion will quickly re-form over scratches. The canisters are stored in protective dry shelters with natural air cooling circulation. Tom Palmisano, SCE vice president, addressed canister scratches during the November 29 Community Engagement Panel meeting. The presentation link is provided here.
Is there a contingency plan for containment of nuclear waste following a canister failure or a leaking canister? (Gary H.; Gene S.)
A canister “failure” is an extremely low probability event. That said, even if a failure of the system should occur, the spent nuclear fuel would be contained within the canister and the steel and cement-shielding provided by the cavity enclosure container that surrounds the canister. There is no liquid in the canister. The fuel pellets are in a solid state, sealed inside a steel fuel rod, which is placed in a fuel assembly. There would be little impact from increased radiation dose in the surrounding area and no impact to the health and safety of the public.
If a canister is breached, is a zirconium fire and/or hydrogen explosion possible? Can fuel cladding deteriorate due to excess heat build-up in the canister while in dry storage? (Gene S.) (Sarah B.)
No. SCE addressed this topic during the 3rd Quarter Community Engagement Panel meeting on Sept. 14, 2017. In the unlikely event of a through-wall crack in a loaded multipurpose canister, there would be minimal to no impact to the site or public:
- There would be an initial inert release of helium
- Any fission gases that did escape would diffuse into the air and never reach site boundaries
- There are no high-pressure forces in the canister to propel contamination into the environment
- Solid fission products such as the fuel pellets would remain in fuel rods in the canister
- And finally, the internal temperature of the used nuclear fuel is such that there is not the level of extreme heat required to ignite such a fire nor cause an explosion
Scientific American explained the process of how a hydrogen explosion can occur in relation to what happened at Fukushima, at the time an operating nuclear plant. “The high temperatures that the fuel rods create boil water and continually turn it into steam. If no fresh water is introduced to cool the rods then they continue to heat up. Once the rods reach more than (2192 degrees Fahrenheit), the zirconium will interact with the steam and split the hydrogen from the water. That hydrogen can then be released from the reactor core and containment vessel and, if it accumulates in sufficient quantities—concentrations of 4 percent or more in the air—it can explode…”
These conditions cannot occur at SONGS. This is because spent fuel rods are cooled sufficiently before being placed into canisters, eliminating the high heat source (the fuel rods could not reach 2192 degrees Fahrenheit). In addition, there is no water within the canisters, only helium, and so no potential hydrogen source.
The link to the 3rd Quarter Community Engagement Panel Meeting presentation Sept. 14, 2017 on the “Development and Implementation of Aging Management Programs for San Onofre” is here (See slides 67 and 68).
The link to the meeting video is here.
Why doesn't the NRC require a more realistic drop test, using one of the flawed shim canisters fully loaded with lead and water to see what happens? (Gary H.)
This question was referred to the NRC.
What you should know: The health and safety of employees and the public was never, and would never have been, impacted by this event due to the robust construction of the canister. The drop analysis, validated by an independent expert and provided to the NRC, confirms canister integrity would not have been breached had a drop occurred. The drop analysis can be found here.
Is SCE required to have a hot cell on site in order to resume fuel transfer operations? (Caroline K.)
There is no requirement to have a hot cell on site in order to continue to move fuel.
Will a hot cell be a viable method for repackaging spent fuel and will SCE be in compliance with its fuel retrievability requirement? (Caroline K.)
A dry transfer system or “hot cell” is one method contemplated in the NRC’s 2014 Generic Environmental Impact Statement for Continued Storage of Spent Fuel (NUREG-2157) for repackaging spent fuel if spent fuel remains on site longer than the life of dry storage canisters. There is no requirement to have a hot cell on site.
SCE has demonstrated to the NRC is ability to meet the NRC’s retrievability requirements, which is documented in the NRC’s Frequently Asked Questions #12.
Can you verify that the helium is properly circulating to cool radioactive waste in the 4 cans with the new shim pin design? (Caroline K.)
The subject canisters were inspected prior to being welded shut and the height of the basket and shims indicated the shim pins were providing support off the bottom of the canister to facilitate helium circulation. In addition, analysis has shown that even without circulation, heat load within the canisters remains within regulatory limits.
What you should know: Since their loading and placement, the four canisters utilizing the shim pin design have exhibited normal temperatures readings, indicating the system is operating as designed.
Helium and shims were two of the topics discussed during the 2nd Quarter Community Engagement Panel Meeting on June 27, 2018. The link to the slide presentation entitled, “SONGS Decommissioning Update” is here (refer to slides 30 thru 35).
Do waste repositories accept seriously damaged fuel? (Gene S.)
Yes, existing dry storage technology contains provisions for storing severely damaged fuel. Note severely damaged Three Mile Island fuel was shipped to, and is stored at, Idaho National Lab. SCE staff believes properly analyzed and packaged severely damaged fuel can be stored in a deep geologic repository.
HOLTEC U-MAX DRY CASK STORAGE SYSTEM
Why doesn’t Edison reject the system they purchased from Holtec immediately? (Gary H.)
The Holtec dry cask storage system provides exceptional protection and shielding to the canisters. The issues raised by the Aug. 3 canister incident had nothing to do with technical issues, rather it was performance issues. There is a tight tolerance that needs to be navigated during downloading. Through training, improved procedures and the addition of new technology, this will be addressed.
What is the purpose of the gusset inside the Divider Shell? (Christine G.)
Gussets are triangular pieces of steel that help provide support to the shield ring inside the divider shell, which sits inside the Cavity Enclosure Container. The shield ring is a very robust piece of steel welded to the divider shell and supported by the gussets. The gussets are not designed to help guide the loading of a multi-purpose canister.
Does the cask shield ring have the potential to become dislodged when pressure is placed on it (e.g., while the canister is being loaded into it)? (Christine G.)
No. The shield ring is capable of supporting the weight of a fully loaded multipurpose canister.
AREVA DRY CASK STORAGE SYSTEM
Are the radiological readings around the Areva dry cask storage high? (Caroline K.)
No, the radiological readings at the Areva dry cask system are normal, as expected, and far below NRC regulatory limits. This was recently independently validated by the San Diego County Department of Environmental Health. The report can be found here.
Does SCE anticipate through-wall cracking on any of the (50) AREVA canisters? How can you be sure that the existing canisters have no cracks? (Caroline K.)
SCE does not anticipate through-wall cracking affecting any of the canisters, AREVA or Holtec, located in the Independent Spent Fuel Storage Installation. SCE is developing an aging management program that will address the long-term monitoring and evaluation of our dry cask storage systems, including chloride-induced stress corrosion cracking. Click here for more information on the aging management program, and here for information regarding chloride-induced stress corrosion cracking and other questions about dry cask storage. Additionally, the canister inspection programs at SONGS include the submission of a plan to the California Coastal Commission in late 2020: “a maintenance and inspection program designed to ensure that the fuel storage casks will remain in a physical condition sufficient to allow both on-site transfer and off-site transport, for the term of the project…” This program could utilize a variety of inspection methods, including mini-robots.
CANISTER LOADING INCIDENT AND CORRECTIVE ACTIONS
How has SCE addressed this incident? Has SCE added additional staff to the MPC downloading crews to prevent a reoccurrence? (Alex R.; Gene S.)
SCE and Holtec have improved training programs and retrained crews, revised procedures to provide additional guidance and detail, added equipment modifications such as load monitoring cameras and alarms, provided more intrusive oversight of operations, and strengthened application of the corrective action program which is now more effective in identifying lessons learned.
SCE has completed the following corrective actions and program enhancements to prevent reoccurrence of the Aug. 3, 2018 incident:
- Improved training programs to include more specific training using detailed procedures and On-the-Job training.
- Revised and enhanced procedures with additional detail and guidance, including downloading alignment and multiple observers.
- Improved load monitoring using independent and redundant features to verify the load, telltale monitoring, camera indications and alarms
- Enhanced oversight with additional SCE staff with Holtec downloading experience and more specific training for the oversight team.
- Re-Training of crews using new procedures and load monitoring and more detailed training for new staff.
- An Independent Readiness Assessment Team reviewed and assessed procedures, equipment, training and practice runs. The team concluded that once all corrective actions are complete, SONGS can safely continue fuel transfer operations.
- Practice runs were performed to validate new procedures, provide on-the-job training and load monitoring, and included oversight by the Independent Readiness Assessment Team.
- The NRC will observe final practice runs.
Much of this information was provided during the November 29 Community Engagement Panel meeting. The presentation link is provided here.
Does SCE have videos of the inspection process before the canisters are loaded, and will it be used for training purposes? (Gene S.)
Yes, videos and simulations of the canister downloading process, including inspections of empty canisters, are incorporated into the training.
Is there a video of the July 22 or the Aug. 3 downloading incidents? (Gene S.)
No. SCE does not have videos of the July 22 or August 3 canister downloading events.
Was canister #29 inspected after the incident or does it need to be pulled out and inspected? (Gene S.)
SCE has concluded there is no need to inspect the canister, and the NRC is reviewing our conclusion.
Where can I find information related to the 25 ft. MPC drop analysis that was submitted to the NRC? (Gene S.)
The drop analysis can be found here on the SONGSCommunity website. It was validated by an independent expert and provided to the NRC, and confirms canister integrity would not have been breached had a drop occurred.
FUEL LOADING PROCESS
How does SCE ensure that the correct fuel assemblies are in the correct location in the basket of the canister? Does this take into consideration burn up and decay time for each? Does SCE have video of this? (Gene S.)
Serial numbers are stamped on the fuel assembly upper end fitting. The serial number is verified by two personnel after placement of the fuel in the core or dry storage canister. A third independent reviewer verifies the serial number (correct placement of the fuel assembly) by viewing a video of the serial number verification.
Burnup is calculated based on a fuel assembly’s operating history in the reactor core. Cooling time is calculated starting from the last day a fuel assembly was operated in the reactor core. Associating the correct burnup and cooling time with a fuel assembly is assured by verifying its placement in the reactor core. SCE has a video of the serial number verifications of all fuel assemblies.
Does SCE have videos of this entire process from start to finish? (Gene S.)
Yes. SCE provides a video of the Fuel Transfer process on the SONGScommunity.com website. Look for the “Featured video." The link is provided here.
The link to the CEP section of our website is provided here.
David Fritch discussed canister #29, was the canister completely inspected before it was loaded? (Gene S.)
Yes, on multiple levels. The canister is fabricated and inspected in accordance with NRC requirements at the manufacturing facility. This includes non-destructive testing, such as weld radiography, weld dye penetrant testing, and confinement boundary helium leaking testing.
Once arriving at the station, it is inspected again prior to loading. Next, all fuel being placed in the canister is visually inspected, and tested for cladding leaks, before being characterized as “intact”, i.e., no cladding breaches. Fuel identified with cladding breaches is being stored in a damaged fuel container, in accordance with NRC requirements.
What is the Emergency Response Plan, and how could local emergency services be adequate to handle urgent, radiological incidents? Does SCE have mitigating responses to the various scenarios? (Caroline K.; Gene S.)
The SONGS Emergency Response Organization (ERO) utilizes emergency implementing procedures for response to all emergencies at San Onofre. In the very unlikely event that a canister was damaged and resulted in a radiological release, actions taken to mitigate a radioactive release from a damaged canister would include engineering contamination and airborne controls such as containment, ventilation, shielding, and/or local isolation.
As long as there is spent fuel on site, SONGS is required by regulation to maintain an onsite emergency plan that includes classification and notification of emergencies to offsite authorities, and coordinate with designated offsite government officials (Orange County, San Diego County, State of California, and Camp Pendleton) following an event declaration so that, if needed offsite authorities may initiate appropriate response actions. SONGS has the capability to notify the State and the local agencies within 15 minutes of an emergency. Periodic drills are conducted with offsite agencies to demonstrate emergency response proficiency, procedure use, dose assessment and environmental monitoring, and timeliness requirements such as notifying the state and offsite within 15 minutes. SONGS also maintains formal agreements with Camp Pendleton Fire and Medical, Air Methods and Mission Hospital, Tri-City Medical Center, and Law Enforcement (FBI, Camp Pendleton, State Parks, California Highway Patrol, and Orange County Sheriffs.)
An emergency operations plan (EOP) is addressed in the Federal Emergency Management Agency’s (FEMA) Comprehensive Preparedness Guide (CPG) 101, “Developing and Maintaining Emergency Operations Plans.” CPG 101 is the foundation for State, territorial, tribal, and local emergency planning in the United States. It promotes a common understanding of the fundamentals of risk-informed planning and decision making, and helps planners at all levels of government in their efforts to develop and maintain viable, all-hazards, all-threats emergency plans. An EOP is flexible enough for use in all emergencies. It describes how people and property will be protected; details who is responsible for carrying out specific actions; identifies the personnel, equipment, facilities, supplies, and other resources available; and outlines how all actions will be coordinated. A CEMP is often referred to as a synonym for “all hazards planning.”
Individual States and local governments have the primary authority and responsibility to protect their citizens and respond to disasters and emergencies and have All Hazards Plans. The resources available to support State and local governments during the transition process include, but are not limited to, the National Preparedness System guidance materials, the Federal Radiological Preparedness Coordinating Committee, and assistance from FEMA headquarters and regional staff.
There is an entire section about emergency planning on SONGScommunity.com. Additionally, during the 3rd Quarter Community Engagement Panel meeting, SCE and the OC Assistant Emergency Manager gave a presentations to the CEP on emergency planning.
The presentation titles and links are provided below:
Decommissioning the San Onofre Nuclear Generating Station – Offsite Impacts by Sara Kaminske Assistant Emergency Manager Chair, SONGS Interjurisdictional Planning Committee Orange County Sheriff’s dept. Emergency Management Division
What is the worst case scenario with regard to spent fuel and how is SCE prepared to handle? (Terry K.)
SCE has an emergency plan in place that takes into consideration the types of accidents that can occur at a decommissioned plant, including a canister breach.
Additionally, SCE is currently working with the CEP Officers and other interested parties to develop the topics for an Extreme Events Workshop. The focus of the workshop will be to answer questions related to worst case scenarios and the Emergency Planning Response.
NRC OVERSIGHT / REPORTABILITY
How can the public be assured that safety incidents/event reports are filed immediately as required by federal law? (Caroline K.)
SCE takes very seriously and strives to comply with all NRC regulations and requirements. The NRC was briefed on the canister downloading event on Monday, August 6, 2018 and then regularly since the event. However, SCE did not initially interpret the regulations to conclude that a formal report was warranted. During the NRC Special Inspection, the NRC shared its interpretation of the regulation and SCE filed the formal report.
Is there anything the Community Engagement Panel can do regarding NRC involvement? (Charles L.)
Yes. The CEP asked the NRC to attend the November 29th Community Engagement Panel Meeting to provide an update the public on the NRC Special Inspection. The CEP has also been in communication with the NRC and SCE regarding the canister downloading event. The CEP will continue to stay updated on any new developments and keep the CEP members and the public informed.
Where can public information be found regarding radioactive releases to the ocean? The annual report found on the internet is not in laymen’s terms. (Christine G.)
Discharges via ocean conduits (liquid releases) are conducted in compliance with the regulations, license and permit requirements provided below:
- Clean Water Act –federal law governing water pollution
- Nuclear Regulatory Commission (NRC) Offsite Dose Calculation Manual (ODCM)
- Environmental Protection Agency (EPA)
State: The State Water Board
Local: San Diego Region - California Regional Water Quality Control Board
All waste water is monitored for radioactivity to ensure compliance with applicable limits; radioactivity is evaluated per the NRC and the EPA. Radioactive releases are now at ~1% of the levels during plant operation. Dose to a hypothetical member of the public remains ~0.003 millirem/year, which is 100,000 times less than national avg. of ~300 millirem/year from natural sources.
SCE is responsible for two Radiological Reports:
- The Annual Radioactive Effluent Release Report covers liquid and gaseous effluent releases. The report provides a conclusion page which summarizes the results.
- The Annual Radiological Environmental Operating Report covers impact on the environment by sampling air, water, soil, kelp, marine life and provides an Executive Summary at the beginning of the report.
Please note: The reports are written to provide the technical information required by the NRC.
Both reports are filed annually with NRC and are available on the NRC and SONGS websites. The SONGS link is here.
The information was also provided during the August 9, 2018 CEP meeting.
How can the data for radioactive releases to the ocean be segregated between SONGS and Camp Pendleton? (Christine G.)
The Annual Radioactive Effluent Report reflects only releases from San Onofre through our NPDES parameters. If San Onofre exceeds a regulatory limit, the regulatory agencies will make a public notice.
Would the process used to filter water at de-salinization plants remove radioactive waste? (Christine G.)
SCE cannot speak for desalination plants, however, for nuclear plants as discussed in the previous questions, our processes do an excellent job at filtering out radioactive waste from water and meeting regulatory release limits. The filters we use to trap contaminants must also be packaged and shipped for storage at low-level waste sites.
What level of compensation would be available to any party who has suffered loss of life, health or property from a nuclear accident? (Gary H.)
SCE has coverage for the San Onofre nuclear plant through two main venues:
$1.5 billion in coverage from Nuclear Electric Insurance Limited (NEIL) which provides onsite coverage for decontamination and property damage
$450 million in coverage from American Nuclear Insurers (ANI) – which provides nuclear liability damages including decontamination, property damage and bodily injury
The insurance information was provided during the 2nd Quarter Community Engagement Panel meeting on June 27, 2018. The link to the slide presentation entitled, “SONGS Decommissioning Update” is here (refer to slide 51).