ML23108A278
| ML23108A278 | |
| Person / Time | |
|---|---|
| Site: | Holtec |
| Issue date: | 04/14/2023 |
| From: | Monica Ford - No Known Affiliation |
| To: | NRC/SECY |
| References | |
| NRC-2022-0109, 88FR9195 00006 | |
| Download: ML23108A278 (1) | |
Text
4/17/23, 4:54 PM blob:https://www.fdms.gov/95301426-69e9-49a2-b121-88453c09e938 As of: 4/17/23, 4:54 PM Received: April 14, 2023 PUBLIC SUBMISSION Status: Pending_Post Tracking No. lgh-b75a-x8hs Comments Due: April 14, 2023 Submission Type: Web Docket: NRC-2022-0109 List of Approved Spent Fuel Storage Casks: Holtec International HI-STORM 100 Cask System, Certificate of Compliance No. 1014, Renewal of Initial Certificate and Amendment Nos. 1 through 15 Comment On: NRC-2022-0109-0007 List of Approved Spent Fuel Storage Casks: Holtec International HI-STORM 100 Cask System, Certificate of Compliance No. 1014, Renewal of Initial Certificate and Amendment Nos. 1 Through 15 Document: NRC-2022-0109-DRAFT-0013 Comment on FR Doc # 2023-05831 Submitter Information Name: Michael Ford Address:
Amarillo, TX, 79109 Email: michael@healthphysics.com Phone: 806-459-9979 General Comment See attached comments from Micheal Ford of HealthPhysics.com Attachments Healthphysics.com Comments on Docket ID NRC-2022-0109 blob:https://www.fdms.gov/95301426-69e9-49a2-b121-88453c09e938 1/1
14 April 2023 Mr. James Firth & Ms. Kristina Banovac, Project Managers Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission
Subject:
RE: Docket ID NRC-2022-0109, List of Approved Spent Fuel Storage Casks: Holtec International HI-STORM 100 Cask System, Certificate of Compliance No. 1014, Renewal of Initial Certificate and Amendment Nos. 1 Through 15
Dear Mr. Firth & Ms. Banovac,
The following comments apply to all 68 documents released for public comment as NRC Proposed Certificates of Compliance and Proposed Technical Specifications on the subject docket. Attachment 1 identifies the documents and associated ADAMs numbers.
General Comment:
Given that the applicant seeks renewal of the subject Certificates of Compliance (CofCs) for an unprecedented period of 40 years and given the history of the substandard quality control processes in which Holtec dry storage canisters (DSCs) were manufactured 20 years ago, it is not unreasonable to demand that extraordinary care and vigilance be required and described in the safety bases for these multiple authorizations, especially as regards the Aging Management Plans (AMPs) deployed for these systems.
Unfortunately, such is not the case. There is no provision within the rudimentary Aging Management Plan (AMP) template developed by the industry to create a condition for responding to discoveries in the causes and mitigations for chloride-induced stress corrosion cracking (CI-SCC). The NRC has specified the minimum possible scrutiny on a population of canisters that will be at three (3) times their initial designed life span at the end of the proposed reauthorization period.
Indeed, the proposed Holtec AMP only requires the assessment of a single dry storage canister (DSC) every 5 +/- 1.25 yrs., which could result in the inspection of one single container out of a HEALTHPHYSICS.COM 5600 BELL ST, STE 105, #291 l AMARILLO, TEXAS 79109 l w: healthphysics.com le: info@healthphysics.com l p: 806.459.9979
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 2 population of dozens or hundreds of containers (proposed CISF) eight times over the proposed 40 year reauthorization period. This is unacceptable.
The NRC and the Department of Energy (DOE) take very different approaches to managing the risk of CI-SCC in spent nuclear fuel DSCs. The NRC attempts to establish the minimum acceptable regulatory requirements for Aging Management Programs (AMPs). In contrast, the DOE conducts research to better understand the causes and consequences of CI-SCC and identify knowledge gaps that must be filled.
The NRC's de minimus AMP Requirements:
The NRC's AMP requirements, such as inspection frequency and visual indicators, may not even be the bare minimum needed to protect the public and the environment and do not acknowledge the potential need to integrate discoveries on the cause and mitigation of CI-SCC into the CofC AMP.
DOE's CI-SCC Research and Knowledge Gaps:
The DOE conducts research to better understand the causes and consequences of CI-SCC in DS and identify and prioritize knowledge gaps. The DOE's research typically includes the following components:
- 1. Investigating the underlying mechanisms: The DOE looks into the factors contributing to the initiation and propagation of CI-SCC, such as material properties, environmental conditions, and stressors.
- 2. Developing advanced detection methods: The DOE is developing and validating advanced non-destructive examination techniques, such as eddy current testing, ultrasonic testing, and remote visual inspection, to detect and characterize CI-SCC.
- 3. Modeling and simulation: The DOE creates models and simulations to predict DSC long-term performance and susceptibility to CI-SCC, taking into account a variety of factors such as material properties, environmental conditions, and stressors.
- 4. Identifying and prioritizing knowledge gaps: The DOE identifies areas where more research is required to better understand CI-SCC and its potential consequences. This could include assessing the efficacy of existing AMPs, inspection methods, or material selection strategies.
HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 3 The NRC should actively track the DOE's research efforts and results to provide a more comprehensive understanding of CI-SCC and inform regulatory decisions such as modifying AMP requirements or developing new guidance and best practices.1 Specific Comments:
- 1. Section 7.1, paragraph 3, Holtec International Hi-Storm 100 Cask System Safety Evaluation Report, page 7-1, the stated leak rate of 5 E -6 std cc/sec helium is sufficient to allow the release of transuranic oxides. The DOE leak tight standard for nuclear weapon components is 1 E-11 to 1 E -12 std cc/sec because of the design lifetime of nuclear weapons. A leak rate of 1 E -6 std cc results in the rejection of the component due to the leak rate.
With the extension of the service life of the DSCs by another 40 years (and likely beyond), the NRC should reassess the acceptable leak rate.
- 2. Section 7.2 to 7.4, Holtec International Hi-Storm 100 Cask System Safety Evaluation Report, page 7-2, given the research being conducted by the DOE detailed by footnote 1, there is no credible basis to
- a. Support the statement in Section 7.4, Since the confinement boundary is welded and the temperature and pressure of the MPC are within the design-basis limits, no discernable leakage is credible, or
- b. Support the conclusions of confinement integrity, worst-case leak rate, or radionuclide releases in Sections 7.2 and 7.3.
- 3. ML20049A083/Attachment 2 to Holtec Letter 5014890, Appendix A: Hi-Storm 100 Aging Management Programs, MPC AMP, pages A-2 to A-5, the AMP intended to be used for each MPC CofC has the following commentary on 4. Detection of Aging Effects,
- a. A visual inspection of the MPC surface shall be performed using a boroscope (or equivalent). The boroscope (or equivalent) inspection shall look at the accessible areas of the MPC surface while the MPC remains in the overpack with the overpack lid installed. This visual inspection shall meet the requirements of a VT-1 DOE Spent Fuel Research for Storage & Transportation, Ned Larson, NWTRB Winter 2022, Meeting Virtual Meeting, March 1, 2022 HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 4 3 Examination, as given in the ASME Boiler & Pressure Vessel Code (B&PVC)
Section XI, Article IWA-2200, to the extent practical.
The inspection shall be performed on one canister at each site that uses the HI-STORM 100 System. Note that if a site has more than one type of canister (for example, MPC-68 and MPC-68Ms), only one canister needs to be inspected. The selection criteria for choosing the canister to inspect should consider the following:
- EPRI Susceptibility Criteria (Technical Report 3002005371)
- Canister Age
- Canister with Lowest Heat Load
- Canister with specific previously identified manufacturing deviation Alternatively, a site may choose to take credit for an inspection done at a different site, as long as the inspection can be shown to have been performed on a reasonably comparable or bounding canister based on the same criteria listed above.
If these detection methods were adequate for the discovery of active CI-SCC zones/sites, the DOE would not be spending tens of millions of dollars to conduct research on the initiation phenomena and mitigation of CI-SCC.
Further, allowing the inspection of a single MPC, irrespective of the number of canisters at a particular site is wholly inadequate for the detection of trends or anomalies. This is particularly concerning given the impending licensing of the Holtec CISF in New Mexico that is literally surrounded by four (4) salt playas.
Inspecting a single DSC among dozens at a given site every 5 +/- 1.25 years is in no way sufficient to ensure the prevention of canister failure due to CI-SCC, particularly at location surrounded by four salt playas. The effectiveness of inspection frequency depends on several factors, including the quality of canister materials, the local environment, the effectiveness of preventive measures, and the susceptibility of the canisters to CI-SCC.
HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 5 The effectiveness of the NRC greenlighted inspection frequency produces the following concerns:
- a. Limited Sample Size: Inspecting only one canister every 5 years (or 8 canisters over a 40-year licensing period) will not provide an adequate representation of the conditions affecting all canisters at the site. With a limited sample size, there is a high risk that potential issues affecting multiple canisters may go undetected.
- b. Variability in Environmental Conditions: The environmental conditions affecting the canisters, such as temperature, humidity, and chloride concentrations, will vary across the site. Inspecting only a single canister will not account for these variations, leading to an underestimation of the risk of CI-SCC.
HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 6
- c. Progression of CI-SCC: in the area of the country laden with the highest concentrations of surface salts (including sizeable concentrations of MgCl) CI-SCC can progress over time, and the time between inspections may be too long to detect and mitigate the issue before it leads to canister failure. A larger and more frequent inspection schedule would ensure the detection of early signs of CI-SCC and allow appropriate corrective actions to be taken.
As an alternative, consider the following Aging Management Program (AMP) elements:
- a. A biennial inspection schedule and larger sample size a minimum of 2 MPCs that are changed by 50% each biennium ranging to an optimal 10% of the entire MPC inventory changing by 50% each time to account for potential variability in environmental conditions and canister susceptibility, and ensuring that the entire canister population is evaluated in 10 years or less allowing for broad trends to emerge.
- b. A robust environmental monitoring program to track changes in temperature, humidity, and chloride concentrations that may increase the risk of CI-SCC.
- c. A proactive approach to preventive measures, including the selection of materials resistant to CI-SCC, the application of protective coatings, and proper site drainage.
- d. Periodic reviews and updates to the AMP based on new information, regulatory changes, or lessons learned from operating experience.
- 4. ML22098A303/Section 3.5.2, Preliminary Safety Evaluation Report For The Hi-Storm 100 Cask System Certificate Of Compliance No. 1014 Renewal Docket No. 72-1014, page 3-22, the following statement is made regarding the evaluation findings of NRC staff regarding the AMPs provided by the applicant:
The staff reviewed the AMPs in the renewal application. The staff performed its review following the guidance in NUREG-1927 and NUREG-2214. The staff evaluated the 10 elements of the applicants MPC AMP, Overpack AMP, Transfer Cask AMP, High Burnup Fuel Assembly AMP, and 100U Concrete AMP that address aging mechanisms and the effects of potential aging that could adversely affect the ability of the SSCs and associated subcomponents to perform their HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 7 intended functions. For each program element, the staff either confirmed consistency with the example AMPs in NUREG-2214 or confirmed that the applicants alternative approach was adequate to manage all credible aging effects. Based on its review, the staff determined that the SSCs will continue to perform their intended functions during the requested period of extended operation. The staff finds the following:
- i. F3.4: The applicant has identified programs that ensure that aging mechanisms and effects will be managed effectively during the period of extended operation, in accordance with 10 CFR 72.240(c)(3).
- 5. Matching program elements of an AMP with AMP program elements developed by industry of which the applicant is a part of does not constitute sufficient due diligence on the part of NRC staff to reach the stated finding. Based on the ongoing research of the DOE, there is zero basis to reach the conclusions stated by NRC staff at 3.5.2 or F3.4.
If you have any questions regarding the comments I have provided, please contact me at your earliest convenience by email michael@healthphysics.com or by phone 806-459-9979.
Very Respectfully, Michael S. Ford, CHP Owner/Analyst HealthPhysics.com Attachment HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 8 ATTACHMENT 1 DOCKET ID NRC-2022-0109 DOCUMENT LIST HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 9 HEALTHPHYSICS.COM.
HealthPhysics.com Comments on Docket ID NRC-2022-0109l 10 HEALTHPHYSICS.COM.