ML14230A913
| ML14230A913 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/18/2014 |
| From: | Einziger R NRC/NMSS/SFST |
| To: | |
| Goshen J | |
| Shared Package | |
| ML14230A903 | List: |
| References | |
| TAC L24475 | |
| Download: ML14230A913 (15) | |
Text
Fuell Performance F P f and Cask Internals Robert E. Einziger, Ph.D.
Meeting to provide Calvert Cliffs Nuclear Power Plant, LLC,, the opportunity pp y to discuss request q for information responses regarding the Calvert Cliffs ISFSI License Renewal with the NRC Staff July 17, 2014 1
Introduction
- Current guidance in NUREG-1927 NUREG 1927 does not address cask/canister internals that are considered important to safety
- Fuel performance for retrievability and cladding integrity functions
- ISG-24 Final Guidance (ML14058B166)
- Staff is considering adding guidance to NUREG 1927 on thi NUREG-1927 this ttopic i
- Aging management program (AMP) based on a surveillance ill d demonstration t ti program 2
AMP Element 1:
Scope of the Program NUREG-1927: The scope of the program should include the specific structures and components subject to an aging management review
- Components/Materials of Construction
- Specify spent fuel maximum burnup
- Specify S if cladding l ddi ttypes and d maximum i cladding l ddi temperature t t
- Environment
- Dry y helium e u
- Aging effects for material/environment combinations
- Fuel cladding breach
- A Assemblybl di distortion t ti
- Residual moisture after drying
- Changes in the hydride structure of the cladding 3
AMP Element 2:
Preventive Actions NUREG-1927: Preventive actions should mitigate or prevent the applicable aging effects
- Casks/Canisters dried per the accepted guidance in NUREG -1536, Standard Review Plan for Dry Cask Storage Systems
- Backfilled with helium cover gas
- Maximum cladding temperature is maintained below the recommended ISG-11 Rev 3 limits 4
AMP Element 3:
Parameters Monitored/ Inspected NUREG-1927: Parameters monitored or inspected should be linked to the effects of aging on the intended functions of the particular structure and component
- Surveillance demonstration program meeting ISG-24:
- Maximum cladding temperature
- Inspection for the presence of fission gas in the cover gas
- Inspection for presence of water vapor in the cover gas
- Inspection for hydrogen to determine that any radiolysis of residual or bound water does not produce a flammable condition
- Profilometry at the completion of the storage period to determine creep deformation
- Gas G puncturingt i att completion l ti off storage t to t determine d t i cladding l ddi stress for creep calculations
- Cladding metallography at the completion of storage to determine condition of cladding hydrides h drides 5
AMP Element 4:
Detection of Aging Effects NUREG-1927: Define method or technique, frequency, sample size, data collection, and timing to ensure timely detection of aging effects
- Surveillance demonstration program meeting ISG-24:
- Calibrated thermocouple lances to measure the radial and axial temperature profile
- Fission gas analysis technique for the cover gas with sensitivity to detect release of 1% of the fission gas produced in 1% of the cask rods with the lowest burnup in the demonstration
- Residual moisture detection technique with sensitivity to detect the vapor pressure at the bottom of the demonstration system
- Hydrogen H d d detection t ti ttechnique h i with ith sensitivity iti it to t detect d t t 2%
hydrogen in the cover gas of the demonstration 6
AMP Element 5:
Monitoring & Trending NUREG-1927: Should provide for prediction of the extent of the effects of aging and timely corrective or mitigative actions
- As information/data from a fuel performance surveillance demonstration program becomes available, the licensee will monitor, evaluate, and trend the information via their Operating Experience Program and/or the Corrective Action Program to determine what actions should be taken to manage fuel and cladding performanceperformance, if any
- Similarly, the licensee will use its Operating Experience g
Program and/or Corrective Action Program g to determine what actions should be taken if it receives information/
data from other sources than the demonstration program on fuel performance 7
AMP Element 6:
Acceptance Criteria NUREG-1927: Acceptance criteria, against which the need for corrective action will be evaluated; should ensure that SSC functions are maintained
- ISG-24 acceptance criteria provide detailed guidance
- Cask internals and fuel performance criteria:
- Temperature: spatial distribution and time history accurately determined - necessary since the behavior of the rods in the demonstration to the behavior expected of the rods in storage is temperature dependent dependent.
- Cladding Creep: total creep strain extrapolated to the total approved storage duration based on the best fit to the data, accounting for initial condition uncertainty shall be less than 1% -
ISG-11 temperature limits are based on limiting creep to <1%
8
AMP Element 6:
Acceptance Criteria NUREG-1927: Acceptance criteria, against which the need for corrective action will be evaluated; should ensure that SSC functions are maintained
- Cask internals and fuel performance criteria:
- Hydrogen - maximum hydrogen content of the cover gas over the approved pp storage g p period shall be extrapolated p from the g gas measurements to be less than 5% - limit for precluding possible flammable mixture
- Drying y g - The moisture content in the cask , accounting g for measurement uncertainty, shall indicate no greater than one liter of residual water after the drying process is complete - Drying limit, in terms of residual moisture, in the SRP NUREG-1536
- Fuel rod breach - fission gas analysis shall not indicate more than 1% of the fuel rod cladding breaches. - Recommended maximum number of cladding breaches during normal conditions of storage for containment analysis by ISG-5 9
AMP Element 7:
Corrective Actions NUREG-1927: Corrective actions, including root cause determination and prevention of recurrence, should be timely
- Licensee Corrective Action Program commensurate with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B
- Licensee Corrective Action Program to capture and evaluate surveillance demonstration program data, other information/data, and additional operating experience to i iti t corrective initiate ti and/ord/ preventative t ti actions:
ti
- Corrective actions to prevent reoccurrence
- Extent of condition to other susceptible p components p
- Timely corrective actions 10
AMP Elements 8:
Confirmation Process NUREG-1927: Confirmation process should ensure that preventive actions are adequate & appropriate corrective actions have been completed & are effective
- Licensee Quality Assurance Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B
- What follow up action is going to be taken to determine whether preventative or corrective actions are a success
- Method to confirm any actions required are taken 11
AMP Elements 9:
Administrative Controls NUREG-1927: Administrative controls should provide a formal review and approval process
- Licensee Quality Assurance Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B
- Training requirements for inspectors or personnel
- Records retention requirements
- Specified p in the Demonstration Project j Plan or alternate surveillance demonstration program meeting the ISG-24 guidance
- Frequency F for f updating d ti AMP based b d on iindustry-wide d t id operational experience 12
AMP Element 10:
Operating Experience NUREG-1927: Include past corrective actions; provide objective evidence to support a determination that the effects of aging will be adequately managed so that the SSC intended functions will be maintained during the period of extended operation
- Surrogate surveillance demonstration programs with storage t conditions diti and d ffuell ttypes similar i il tto ththose iin th the dry storage system that satisfies the ISG-24 acceptance criteria is a viable method to obtain operating p g experience p
- DOE Dry Cask Storage Demonstration Project is viable as a surrogate surveillance program for the industry
- Additional data/research to assess fuel performance 13
References
- NUREG-1927 - Standard Review Plan for Renewal of Spent Fuel Dry Cask Storage System Licenses and Certificates of Compliance http://pbadupws nrc gov/docs/ML1110/ML111020115 pdf http://pbadupws.nrc.gov/docs/ML1110/ML111020115.pdf
- NUREG-1536, Rev 1 - Standard Review Plan for Spent Fuel Dry Storage Systems at a General License Facility http://www nrc gov/reading rm/doc http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1536/r1/sr1536r1.pdf
- ISG-5, Rev 1 - Confinement Evaluation http://www.nrc.gov/reading-rm/doc-collections/isg/isg-5R1.pdf
- ISG-11, Rev 3 - Cladding Considerations for the Transportation and Storage of Spent Fuel http://www.nrc.gov/reading-rm/doc-collections/isg/isg-11R3.pdf
- ISG The Use of a Demonstration Program as a Surveillance Tool for Confirmation of Integrity for Continued Storage of High Burnup Fuel Beyond 20 Years (ML14058B166) 14
- AMP - Aging Management Program
- CFR - Code of Federal Regulations
- DOE - U.S. Department of Energy
- ISG - Interim Staff Guidance
- SRP - Standard Review Plan 15