ML052380037
| ML052380037 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 08/31/2005 |
| From: | NRC/NMSS/SFPO |
| To: | |
| Hall J, NMSS/SFPO (301) 415-1336 | |
| References | |
| TAC L23683 | |
| Download: ML052380037 (18) | |
Text
Enclosure 2 SAFETY EVALUATION REPORT DOCKET NO. 72-27 HUMBOLDT BAY INDEPENDENT SPENT FUEL STORAGE INSTALLATION Materials License No. SNM-2513 August 2005
iii CONTENTS Section Page TABLES................................................................ xi ACRONYMS............................................................. xii EXECUTIVE
SUMMARY
xiii 1
GENERAL DESCRIPTION...........................................
1-1 1.1 Conduct of Review 1-1 1.1.1 Introduction to the Humboldt Bay Independent Spent Fuel Storage Installation............................
1-1 1.1.2 General Description of the Location.........................
1-3 1.1.3 General Systems Description..............................
1-3 1.1.4 Identification of Agents and Contractors.....................
1-5 1.1.5 Material Incorporated by Reference.........................
1-5 1.2 Evaluation Findings...........................................
1-5 1.3 References.................................................
1-5 2
SITE CHARACTERISTICS...........................................
2-1 2.1 Conduct of Review 2-1 2.1.1 Geography and Demography..............................
2-1 2.1.1.1 Site Location....................................
2-2 2.1.1.2 Site Description..................................
2-2 2.1.1.3 Population Distribution and Trends...................
2-3 2.1.1.4 Land and Water Uses.............................
2-4 2.1.2 Nearby Industrial, Transportation, and Military Facilities.........
2-5 2.1.3 Meteorology...........................................
2-6 2.1.3.1 Regional Climatology..............................
2-6 2.1.3.2 Local Meteorology................................
2-7 2.1.3.3 Onsite Meteorological Measurement Program...........
2-8 2.1.4 Surface Hydrology......................................
2-8 2.1.4.1 Hydrologic Description.............................
2-8 2.1.4.2 Floods.........................................
2-9 2.1.4.3 Probable Maximum Flood on Streams and Rivers........
2-9 2.1.4.4 Potential Dam Failures (Seismically Induced)........... 2-10 2.1.4.5 Probable Maximum Surge and Seiche Flooding......... 2-10 2.1.4.6 Probable Maximum Tsunami Flooding................. 2-11 2.1.4.7 Ice Flooding..................................... 2-12 2.1.4.8 Flood Protection Requirements...................... 2-12 2.1.4.9 Environmental Acceptance of Effluents................ 2-13 2.1.5 Subsurface Hydrology................................... 2-13 2.1.5.1 Stratigraphy..................................... 2-13 2.1.5.2 Aquifers........................................ 2-14 2.1.5.3 Groundwaters Recharge, Gradients, and Discharge...... 2-15 2.1.5.4 Hydraulic Properties of Aquifers..................... 2-16
iv CONTENTS (continued)
Section Page 2.1.5.5 Groundwater Use
................................ 2-16 2.1.5.6 Groundwater Quality.............................. 2-17 2.1.5.7 Contaminant Transport Analysis..................... 2-17 2.1.6 Geology and Seismology................................. 2-18 2.1.6.1 Basic Geologic and Seismic Information............... 2-18 2.1.6.2 Ground Vibration................................. 2-23 2.1.6.3 Surface Faulting................................. 2-29 2.1.6.4 Stability of Subsurface Materials..................... 2-30 2.1.6.5 Slope Stability................................... 2-35 2.2 Evaluation Findings........................................... 2-42 2.3 References................................................. 2-43 3
OPERATION SYSTEMS.............................................
3-1 3.1 Conduct of Review 3-1 3.1.1 Operation Description 3-1 3.1.2 Spent Nuclear Fuel Handling Systems.......................
3-5 3.1.3 Other Operating Systems.................................
3-5 3.1.4 Operation Support Systems..............................
3-5 3.1.5 Control Room and Control Area............................
3-6 3.1.6 Analytical Sampling.....................................
3-6 3.1.7 Shipping Cask Repair and Maintenance.....................
3-6 3.1.8 Pool and Pool Facility Systems............................
3-6 3.2 Evaluation Findings...........................................
3-6 3.3 References.................................................
3-7 4
STRUCTURES, SYSTEMS, AND COMPONENTS AND DESIGN CRITERIA EVALUATION............................................
4-1 4.1 Conduct of Review 4-1 4.1.1 Materials to be Stored...................................
4-2 4.1.2 Classification of Structures, Systems, and Components.........
4-2 4.1.2.1 Classification of Structures, Systems, and Components -
Items Important to Safety...........................
4-3 4.1.2.2 Classification of Structures, Systems, and Components -
Items Not Important to Safety.......................
4-3 4.1.2.3 Classification of Structures, Systems, and Components -
Conclusion......................................
4-4 4.1.3 Design Criteria for Structures, Systems, and Components Important to Safety..............................................
4-4 4.1.3.1 General........................................
4-4 4.1.3.2 Structural.......................................
4-5 4.1.3.3 Thermal........................................ 4-15 4.1.3.4 Shielding and Confinement......................... 4-16
v CONTENTS (continued)
Section Page 4.1.3.5 Criticality....................................... 4-17 4.1.3.6 Decommissioning
................................ 4-18 4.1.3.7 Retrieval....................................... 4-18 4.1.4 Design Criteria for Other Structures, Systems, and Components.. 4-18 4.2 Evaluation Findings........................................... 4-19 4.3 References................................................. 4-21 5
INSTALLATION AND STRUCTURAL EVALUATION.......................
5-1 5.1 Conduct of Review 5-1 5.1.1 Confinement Structures, Systems and Components............
5-1 5.1.1.1 Description of Confinement Structures................
5-2 5.1.1.2 Design Criteria for Confinement Structures.............
5-2 5.1.1.3 Material Properties for Confinement Structures..........
5-3 5.1.1.4 Structural Analysis for Confinement Structures..........
5-4 5.1.2 Pool and Pool Confinement Facilities........................
5-5 5.1.3 Reinforced Concrete Structures............................
5-5 5.1.3.1 Description of Reinforced Concreted Structures.........
5-5 5.1.3.2 Design Criteria for Reinforced Concrete Structures.......
5-5 5.1.3.3 Material Properties for Reinforced Concrete Structures 5-6 5.1.3.4 Structural Analysis for Reinforced Concreted Structures...
5-6 5.1.4 Other Structures, Systems, and Components Important to Safety..
5-8 5.1.4.1 Description of Other Structures, Systems, and Components Important to Safety.....................
5-9 5.1.4.2 Design Criteria for Other Structures, Systems, and Components Important to Safety..................... 5-11 5.1.4.3 Material Properties for Other Structures, Systems, and Components Important to Safety..................... 5-13 5.1.4.4 Structural Analysis for Other Structures, Systems, and Components Important to Safety..................... 5-16 5.1.5 Other Structures, Systems, and Components Not Important to Safety.............................................. 5-21 5.1.5.1 Description of Other Structures, Systems, and Components Not Important to Safety............................. 5-21 5.1.5.2 Design Criteria for Other Structures, Systems, and Components Not Important to Safety.................. 5-21 5.1.5.3 Material Properties for Other Structures, Systems, and Components Not Important to Safety.................. 5-22 5.1.5.4 Structural Analysis for Other Structures, Systems, and Components Not Important to Safety.................. 5-22 5.2 Evaluation Findings........................................... 5-22 5.3 References................................................. 5-24
vi CONTENTS (continued)
Section Page 6
THERMAL EVALUATION............................................
6-1 6.1 Conduct of Review 6-1 6.1.1 Decay Heat Removal Systems.............................
6-1 6.1.2 Material Temperature Limits...............................
6-3 6.1.3 Thermal Loads and Environmental Conditions.................
6-4 6.1.4 Analytical Methods, Models, and Calculations.................
6-5 6.1.5 Fire and Explosion Protection.............................
6-6 6.1.5.1 Fire............................................
6-6 6.1.5.1.1 Bounding Events..........................
6-6 6.1.5.1.2 Engulfing Fire Thermal Evaluation............
6-7 6.1.5.1.3 Nonengulfing Fire Thermal Evaluation.........
6-7 6.1.5.2 Explosion.......................................
6-8 6.1.5.2.1 In-Transit Explosions.......................
6-9 6.1.5.2.2 Explosions Affecting the ISFSI in a Storage Configuration......................
6-9 6.2 Evaluation Findings........................................... 6-10 6.3 References................................................. 6-11 7
SHIELDING EVALUATION...........................................
7-1 7.1 Conduct of Review 7-1 7.1.1 Contained Radiation Sources 7-1 7.1.1.1 Gamma and Neutron Sources.......................
7-2 7.1.2 Storage and Transfer Systems 7-3 7.1.2.1 Design Criteria...................................
7-3 7.1.2.2 Design Features.................................
7-3 7.1.3 Shielding Composition and Details..........................
7-4 7.1.3.1 Composition and Material Properties..................
7-4 7.1.3.2 Shielding Details.................................
7-4 7.1.4 Analysis of Shielding Effectiveness.........................
7-5 7.1.4.1 Computational Methods and Data....................
7-5 7.1.4.2 Dose Rate Estimates..............................
7-6 7.1.5 Confirmatory Calculations................................
7-7 7.2 Evaluation Findings...........................................
7-9 7.3 References.................................................
7-9 8
CRITICALITY EVALUATION..........................................
8-1 8.1 Conduct of Review 8-1 8.1.1 Criticality Design Criteria and Features......................
8-1 8.1.1.1 Criticality Design Criteria...........................
8-2 8.1.1.2 Features.......................................
8-2 8.1.2 Stored Material Specifications.............................
8-3
vii CONTENTS (continued)
Section Page 8.1.3 Analytical Means.......................................
8-4 8.1.3.1 Model Configuration 8-4 8.1.3.2 Material Properties................................
8-5 8.1.4 Applicant Criticality Analysis...............................
8-7 8.1.4.1 Computer Program...............................
8-7 8.1.4.2 Multiplication Factor...............................
8-8 8.1.4.3 Benchmark Comparisons 8-8 8.1.4.4 Independent Criticality Analysis......................
8-8 8.2 Evaluation Findings...........................................
8-8 8.3 References.................................................
8-9 9
CONFINEMENT EVALUATION........................................
9-1 9.1 Conduct of Review 9-1 9.1.1 Review of Design Features...............................
9-1 9.1.2 Confinement Monitoring..................................
9-2 9.1.3 Protection of Store Materials from Degradation................
9-2 9.2 Evaluation Findings...........................................
9-3 9.3 References.................................................
9-4 10 CONDUCT OF OPERATIONS EVALUATION............................
10-1 10.1 Conduct of Review 10-1 10.1.1 Organizational Structure 10-2 10.1.1.1 Corporate Organization..........................
10-2 10.1.1.2 Onsite Organization.............................
10-3 10.1.1.3 Management and Administrative Controls............
10-5 10.1.2 Preoperational Testing and Startup Operations...............
10-6 10.1.2.1 Preoperational Testing Plan.......................
10-6 10.1.2.2 Startup Plan...................................
10-6 10.1.3 Normal Operations.....................................
10-8 10.1.3.1 Procedures....................................
10-8 10.1.3.2 Records...................................... 10-10 10.1.4 Personnel Selection, Training, and Certification
.............. 10-10 10.1.4.1 Personnel Organization.......................... 10-10 10.1.4.2 Selection and Training of Operating Personnel........ 10-11 10.1.4.3 Selection and Training of Security Guards............ 10-12 10.1.5 Emergency Planning................................... 10-12 10.1.6 Physical Security and Safeguards Contingency Plans.......... 10-13 10.2 Evaluation Findings.......................................... 10-13 10.3 References................................................ 10-15
viii CONTENTS (continued)
Section Page 11 RADIATION PROTECTION EVALUATION..............................
11-1 11.1 Conduct of Review 11-1 11.1.1 As Low As Reasonably Achievable Considerations............
11-1 11.1.1.1 As Low As Reasonably Achievable Policy and Program.
11-1 11.1.1.2 Design Considerations...........................
11-2 11.1.1.3 Operational Considerations.......................
11-3 11.1.2 Radiation Protection Design Features......................
11-3 11.1.2.1 Installation Design Features.......................
11-4 11.1.2.2 Access Control.................................
11-4 11.1.2.3 Radiation Shielding.............................
11-5 11.1.2.4 Confinement and Ventilation......................
11-5 11.1.2.5 Area Radiation and Airborne Radioactivity Monitoring Instrumentation.......................
11-6 11.1.3 Dose Assessment.....................................
11-6 11.1.3.1 Onsite Doses..................................
11-6 11.1.3.2 Offsite Doses..................................
11-7 11.1.4 Health Physics Program.................................
11-9 11.1.4.1 Organization...................................
11-9 11.1.4.2 Equipment, Instrumentation, and Facilities............
11-9 11.1.4.3 Policies and Procedures.......................... 11-10 11.2 Evaluation Findings.......................................... 11-10 11.3 References................................................ 11-11 12 QUALITY ASSURANCE EVALUATION 12-1 12.1 Conduct of Review 12-1 12.2 Evaluation Findings..........................................
12-2 12.3 References................................................
12-2 13 FINANCIAL QUALIFICATIONS AND DECOMMISSIONING EVALUATION.....
13-1 13.1 Conduct of Review 13-1 13.1.1 Financial Qualifications Evaluation.........................
13-1 13.1.1.1 Humboldt Bay Power Plant Decommissioning Funding 13-1 13.1.1.2 Financial Qualifications for Humboldt Bay ISFSI.......
13-1 13.1.2 Decommissioning Evaluation.............................
13-4 13.1.2.1 Design and Operational Features..................
13-4 13.1.2.2 Decommissioning Plan..........................
13-5 13.1.2.2.1 General Provisions......................
13-5 13.1.2.2.2 Cost Estimate..........................
13-5 13.1.2.2.3 Financial Assurance Mechanism and Record keeping.....................
13-6 13.2 Evaluation Findings.........................................
13-6 13.3 References................................................
13-7
ix CONTENTS (continued)
Section Page 14 WASTE CONFINEMENT AND MANAGEMENT EVALUATION..............
14-1 14.1 Conduct of Review 14-1 14.1.1 Waste Source........................................
14-1 14.1.2 Off-Gas Treatment and Ventilation 14-2 14.1.3 Liquid Waste Treatment and Retention.....................
14-2 14.1.4 Solid Wastes.........................................
14-3 14.1.5 Radiological Impact of Normal Operations...................
14-3 14.2 Evaluation Findings.........................................
14-3 14.3 References................................................
14-4 15 ACCIDENT ANALYSIS.............................................
15-1 15.1 Conduct of Review 15-1 15.1.1 Off-Normal Events.....................................
15-1 15.1.1.1 Off-Normal Pressures..........................
15-2 15.1.1.2 Off-Normal Environmental Temperatures...........
15-2 15.1.1.3 Confinement Boundary Leakage.................
15-3 15.1.1.4 Cask Drop Less Than Design Allowable Height......
15-3 15.1.1.5 Loss of Electrical Power........................
15-4 15.1.1.6 Cask Transporter Off-Normal Operation............
15-5 15.1.2 Accidents............................................
15-5 15.1.2.1 Earthquake..................................
15-6 15.1.2.2 Tornadoes and Missiles Generated by Natural Phenomena...........................
15-9 15.1.2.3 Flood....................................... 15-11 15.1.2.4 Tsunami.................................... 15-12 15.1.2.5 Fire........................................ 15-12 15.1.2.6 Explosions
.................................. 15-21 15.1.2.7 Drops and Tipover............................ 15-30 15.1.2.8 Leakage from Confinement Boundary............. 15-31 15.1.2.9 Misloading of a Damaged Fuel Assembly........... 15-31 15.1.2.10 Extreme Environmental Temperature.............. 15-32 15.1.2.11 100-Percent Fuel Rod Rupture................... 15-32 15.1.2.12 Lightning.................................... 15-33 15.1.2.13 Turbine Missiles.............................. 15-33 15.1.2.14 Blockage of Multi-Purpose Canister Vent Holes...... 15-34 15.1.2.15 Aircraft Crash Hazards......................... 15-35 15.1.2.15.1 Aircraft Taking Off and Landing at Nearby Airports..................... 15-37 15.1.2.15.2 Flights Along Federal Routes V-27, V-195, and V-494................... 15-40 15.1.2.15.3 Flights Along Federal Route V-607...... 15-41 15.1.2.15.4 High Altitude Airspace
............... 15-43
x CONTENTS (continued)
Section Page 15.1.2.15.5 Military Aviation Along Route VR-1251... 15-44 15.1.2.15.6 Probability Acceptance Criterion for Aircraft Crash Hazards............... 15-44 15.1.2.15.7 Summary of Aircraft Hazards Review.... 15-45 15.1.2.15.8 Future Developments................ 15-45 15.2 Evaluation Findings.......................................... 15-46 15.3 References................................................ 15-49 16 TECHNICAL SPECIFICATIONS......................................
16-1 16.1 Conduct of Review 16-1 16.1.1 Functional/Operating Limits, Monitoring Instruments, and Limiting Control Settings.......................................
16-1 16.1.2 Limiting Conditions/Surveillance Requirements...............
16-2 16.1.3 Design Features.......................................
16-3 16.1.4 Administrative Controls 16-3 16.1.5 License Conditions.....................................
16-4 16.2 Evaluation Findings.........................................
16-5 16.3 References................................................
16-5 APPENDIX - TITLE 10 CODE OF FEDERAL REGULATIONS APPLICABLE TO THE HUMBOLDT BAY INDEPENDENT SPENT FUEL STORAGE INSTALLATION... A-1
xi TABLES Table Page 13-1 Humboldt Bay Decommissioning Funding Status.........................
13-2 15-1 Summary of Estimated Annual Aircraft Crash Hazard Frequency at the Proposed Humboldt Bay ISFSI............................................... 15-47 16-1 Functional/Operating Limits, Monitoring Instruments, and Limiting Control Settings...................................................
16-2 16-2 Limiting Conditions for Operation and Surveillance Requirements............
16-2 16-3 Design Features..................................................
16-3 16-4 Administrative Controls.............................................
16-4 16-5 License Conditions................................................
16-4
xii HUMBOLDT BAY ISFSI SER ACRONYMS American Welding Society AWS as low as is reasonably achievable ALARA boiling water reactor BWR California Public Utilities Commission CPUC Certificate of Compliance CoC cyclic stress ratio CSR damaged fuel container DFC design basis earthquake DBE design earthquake DE deterministic seismic hazard analysis DSHA Final Safety Analysis Report FSAR finite element model FEM Greater than Class C GTCC Humboldt Bay Power Plant HBPP Independent Spent Fuel Storage Installation ISFSI Limiting Condition for Operation LCO mean higher high water MHHW mean lower low water MLLW mean sea level MSL megawatt-electric MWe multi-purpose canister MPC Pacific Gas and Electric Company PG&E peak ground accelerations PGA probabilistic seismic hazard analyses PSHA probable maximum flood PMF quality assurance QA Refueling Building RFB Safety Analysis Report SAR Safety Evaluation Report SER Senior Seismic Hazard Analysis Committee SSHAC soil-structure-interaction SSI spent fuel pool SFP spent nuclear fuel SNF standard penetration test SPT square root of the sum of squares SRSS structures, systems, and components SSCs surveillance requirement SR Thermoluminescent Dosimeter TLD U.S. Nuclear Regulatory Commission NRC
xiii EXECUTIVE
SUMMARY
On December 15, 2003, the Pacific Gas and Electric (PG&E) Company submitted a license application in accordance with 10 CFR Part 72 to the U.S. Nuclear Regulatory Commission (NRC) to construct and operate an independent spent fuel storage installation (ISFSI) on the site of the Humboldt Bay Power Plant (HBPP). The application consists of the following documents:
(1)
A License Application - the applicant describes itself and provides (i) general and financial information, as required by 10 CFR §72.22; (ii) an Emergency Plan as required by 10 CFR §72.32; (iii) Proposed Technical Specifications, as required by 10 CFR §72.26; (iv) a Training Program, as required by 10 CFR §72.192; (v) a Quality Assurance Program, as required by 10 CFR §72.24; and (vi) a Preliminary Decommissioning Plan, as required by 10 CFR §72.30.
(2)
A Safety Analysis Report (SAR) - the applicant describes its plans for designing, constructing, operating, maintaining, and decommissioning the proposed ISFSI, as required by 10 CFR §72.24.
(3)
An Environmental Report - the applicant provides the information the staff uses in performing its environmental assessment of the proposed ISFSI, as required by 10 CFR §72.34. This review is accomplished in parallel with the staffs safety evaluation and is documented in a separate environmental assessment by the NRC staff.
(4)
A Physical Security Plan - the applicant describes its plans for ensuring that the ISFSI and nuclear material are appropriately protected. This is a separate safeguards document not releasable to the public. It includes the Security Training and Qualification Plan and Safeguards Contingency Plan, as required by 10 CFR §72.180 and §72.184. This review is accomplished in parallel with the staffs safety evaluation and is documented in a separate security evaluation by the NRC staff.
The staff has documented its review and conclusions on the safety-related aspects of the license application in this Safety Evaluation Report (SER). The technical review was carried out according to the applicable NRC regulations in 10 CFR Part 20 and Part 72. Review of the SAR was conducted following guidance in NUREG-1567 (U.S. Nuclear Regulatory Commission, 2000) and other applicable regulatory guides and interim staff guidance. This SER documents the NRC staffs review of the design, operation, and other safety aspects of the proposed Humboldt Bay ISFSI, as described in the above submittals, except for the Environmental Report and Physical Security Plan. The Environmental Report is the subject of a separate Environmental Assessment, and the Physical Security Plan is the subject of a separate security evaluation, to be issued by the NRC staff. This executive summary provides a brief overview and summary of this SER.
xiv Amendment 1 of the SAR (Pacific Gas and Electric Company, 2004a) was submitted in October 2004 and incorporated the applicants responses to the staffs request for additional information (Pacific Gas and Electric, 2004b). Supplemental information related to the staffs request for additional information is documented in subsequent letters from the applicant (Pacific Gas and Electric, 2005). As documented in this SER, the staffs review of the SAR is primarily based on the amended information provided in the SAR and on the cited supplemental information.
The HBPP consists of five generating units. Unit 3, the only nuclear unit, is a boiling water reactor (BWR) that was operated for approximately 13 years before being shut down in July 1976. The reactor has remained inactive since that time. In 1983, PG&E concluded that the seismic and other plant modifications required, in part, as a result of the Three Mile Island accident in 1979, were not economical and opted to decommission the plant. The remaining spent nuclear fuel (SNF) from reactor operation is currently stored in the spent fuel pool (SFP) in Unit 3. The other electrical generating units are conventional units capable of operating on fuel oil or natural gas (Units 1 and 2) and gas turbines (Units 4 and 5).
The proposed Humboldt Bay ISFSI will store SNF and associated radioactive material from Unit 3. Spent fuel assemblies will be relocated from wet storage in the Unit 3 SFP to dry storage containers at the proposed ISFSI. The Humboldt Bay ISFSI will facilitate dismantling the existing Unit 3 structures and provide for earlier termination of the 10 CFR Part 50 license for Unit 3. A 10 CFR Part 50 license amendment request to permit cask handling activities in the HBPP refueling building (RFB) has been submitted to NRC. The SNF that will be stored in the proposed ISFSI will need to remain there until a U.S. Department of Energy or other facility is available for further interim storage or permanent disposal.
The Humboldt Bay ISFSI consists of a below-grade storage vault, onsite cask transporter, and dry cask storage system. The applicant will use a modified version of the Holtec International HI-STAR 100 dry cask storage system for the HBPP SNF, referred to as the HI-STAR HB dry cask storage system. The HI-STAR HB system incorporates a cask design that is suitable for both storage and transportation; however, the scope of this licensing action is limited to onsite SNF storage under 10 CFR Part 72. The HI-STAR HB cask provides structural protection and radiation shielding for the multi-purpose canister (MPC-HB) containing the SNF. The onsite handling of the HI-STAR HB cask will be accomplished using a tracked transporter. The transporter developed for the Diablo Canyon ISFSI will be used for the Humboldt Bay ISFSI.
Description of Humboldt Bay Independent Spent Fuel Storage Installation Site According to the license application, the Humboldt Bay ISFSI will be co-located with the HBPP on PG&E-owned property, which is located on the northern California coast approximately 5 km
[3 mi] south of Eureka, California. The applicant owns approximately 0.57 km2 [143 acres] of land on the shore of Humboldt Bay opposite the bay entrance, with water areas extending approximately 150 m [500 ft] into Humboldt Bay from the land area. The owner-controlled area is not traversed by public highways or railroads. A public trail to access a breakwater for fishing traverses the owner-controlled area. However, 10 CFR §72.106(c) allows the controlled area to be traversed as long as appropriate and effective arrangements are made to control traffic and protect public health and safety. The public trail crossing the PG&E property to the north of the ISFSI will be controlled by fences and gates. The gates will be open to allow access to the
xv public trail during normal ISFSI storage operation. During cask transfer and handling operations, the gates will be locked to prevent public access within the controlled area until the cask transfer activities and any corrective actions are completed. If an accident should occur within the controlled area during normal ISFSI storage operation, the applicant will assess radiological conditions. If radiation levels exceed the allowable levels for public health and safety, the gates will be closed and locked to prevent public access within the controlled area until radiological conditions return to allowable levels. The applicant has full authority to control all activities within the ISFSI site and owner-controlled area.
Description of the Humboldt Bay Independent Spent Fuel Storage Installation Storage System The Humboldt Bay ISFSI consists of a below-grade storage vault, onsite cask transporter, and dry cask storage system. The ISFSI is designed to store up to 400 SNF assemblies from HBPP Unit 3 in five casks, with a sixth cask to store Greater than Class C (GTCC) waste.
The dry cask storage system selected by the applicant is the Holtec International HI-STAR HB system. This is a variation of the HI-STAR 100 system, which has been certified by NRC (U.S. Nuclear Regulatory Commission, 2001a,b) for use by 10 CFR Part 50 licensees under the general license provisions of 10 CFR §72.210. The HI-STAR HB system is comprised of the MPC-HB, which is a seal-welded canister containing 80 SNF assemblies; damaged fuel containers (DFC), which can be inserted into an MPC-HB and can hold an intact fuel assembly or damaged fuel; and the HI-STAR HB storage overpack (or cask). The design and operation of these components are described in detail in the HI-STAR 100 System Final Safety Analysis Report (Holtec International, 2002). Holtec developed the modified (shorter) HI-STAR HB cask system for use at Humboldt Bay because of the smaller HBPP fuel assembly dimensions (length and width). It should be noted that the issuance of a 10 CFR Part 72 site-specific license to PG&E only authorizes the applicant to use the HI-STAR HB storage system at the Humboldt Bay ISFSI; this licensing action is not a revision or amendment to the existing NRC approval for the HI-STAR 100 system.
The MPC-HB provides the confinement boundary for the SNF and associated nonfuel hardware. An integrally welded pressure vessel holds up to 80 HBPP SNF assemblies. The MPC-HBs are welded cylindrical structures consisting of a honeycomb fuel basket, a baseplate, a canister shell, a lid, and a closure ring. The honeycomb fuel basket uses geometric spacing and fixed neutron absorbers for criticality control. The MPC-HB is made entirely of stainless steel, except for the neutron absorbers and aluminum seal washers in the vent and drain ports.
The HI-STAR HB storage cask provides an internal, cylindrical cavity of sufficient size to house the MPC-HB during loading, unloading, transfer and storage activities. The storage cask is a rugged, heavy-walled cylindrical container constructed of carbon steel. The overpack provides gamma and neutron shielding and protects the MPC-HB from missiles and natural phenomena during onsite transfer and storage.
The cask storage vault is comprised of six below-grade, cylindrical storage cells that are structural units constructed of steel-reinforced concrete with a carbon steel liner. The vault provides additional shielding and defense-in-depth of the casks from missiles and natural phenomena. The vault is sized to hold five HI-STAR HB casks with SNF and one GTCC certified cask. The storage vault is located at about 183 m [600 ft] from the RFB inside a
xvi security area that has applicable barriers, access, and surveillance controls that meet 10 CFR §73.51 requirements.
A transporter is used to move the HI-STAR HB cask from outside the RFB to the ISFSI. The transporter developed for the Diablo Canyon ISFSI will be used for the Humboldt Bay ISFSI.
The transporter is a U-shaped tracked vehicle consisting of the vehicle main frame, hydraulic lifting towers, an overhead beam system that connects between the lifting towers, a cask restraint system, the drive and control systems, and a series of cask lifting attachments. The transporter design permits the HI-STAR HB cask to be handled vertically. The transporter also is used to lower the HI-STAR HB cask into the storage vault.
Safety of the Humboldt Bay Independent Spent Fuel Storage Installation The staff has determined that the proposed Humboldt Bay ISFSI and the HI-STAR HB cask design are structurally sound and that the SNF will remain safe within the canister during all phases of operation for normal, off-normal, and accident conditions. The analyses included all plausible natural and human-made phenomena, many of which had already been accepted by the staff in its review of the HI-STAR 100 dry cask storage system (U.S. Nuclear Regulatory Commission, 2001a) and in previous staff reviews of HBPP licensing actions. After reviewing the applicants analyses, the staff concluded that the Humboldt Bay ISFSI and the HI-STAR HB system design are structurally safe and will meet all applicable regulatory requirements.
The staff has also determined that the applicant has shown that the SNF within the storage casks will remain subcritical (i.e., unable to sustain a nuclear chain reaction) during all phases of operation for both normal conditions and credible accident conditions. The applicant has provided radiation dose estimates for the surrounding public and the workers at the ISFSI. The MPC-HB will be welded closed to prevent leakage of radioactive material. Additional shielding is provided by the overpack and the below-grade reinforced concrete vault.
The amount of radiation to which a person is exposed is called a dose. The applicant has estimated that members of the public nearest to the proposed ISFSI would receive doses below NRC regulatory requirements, which for normal conditions of operation is 0.25 mSv/yr
[25 mrem/yr] and for credible accidents is 0.05 Sv/yr [5 rem/yr]. Radiation dose rates will be calculated within the vicinity of individual casks to demonstrate that workers at the proposed ISFSI will not receive doses that exceed 0.05-Sv/yr [5 rem/yr], the NRC annual regulatory limit for workers at nuclear facilities. These radiation dose limits have been established by NRC to prevent any undue risk and to ensure the safety of all members of the public and workers at a nuclear facility. The applicant has described its radiation protection program, which employs an as low as is reasonably achievable (ALARA) radiation protection principle. Radiation doses received by the workers and dose rates within the vicinity of the storage pad will be monitored to verify that radiation dose limits are not exceeded. The staff reviewed the analyses provided by the applicant and concluded that the Humboldt Bay ISFSI and HI-STAR HB system designs are radiologically safe and will meet regulatory requirements.
As required by 10 CFR Part 72, the applicant demonstrated that all components of its proposed ISFSI that are important to safety would continue to perform their design functions during normal, and off-normal conditions and during any credible accidents that could be postulated to occur. Based on its review and evaluation of the information provided, the staff concluded that
xvii the applicant has provided acceptable analyses of the design and performance of these structures, systems, and components important to safety under normal, off-normal, and accident conditions.
The staff further concluded that the applicants analyses related to off-normal and accident events demonstrate that the proposed ISFSI will be sited, designed, constructed, and operated so that during all credible off-normal and accident events, public health and safety will be adequately protected.
The HI-STAR HB system was evaluated against the parameters and conditions specific to the site and the SNF to be stored. Based on its review, the staff finds that the use of the HI-STAR HB system as proposed for the Humboldt Bay ISFSI is acceptable, in accordance with the site-specific license provisions of 10 CFR Part 72, subject to all conditions of the license.
Other Requirements To demonstrate its financial qualifications, the applicant identified anticipated sources of funds for the ISFSI project. The staff concludes in Chapter 13 of this SER that the applicant has provided reasonable assurance of its financial qualifications for construction, operation, and decommissioning of the proposed ISFSI.
The staff also found the revisions to the HBPP Physical Security Plan to incorporate the ISFSI to be acceptable. The staffs security evaluation of the revised plan was transmitted as a separate safeguards document that is not available to the public.
REFERENCES Holtec International. Final Safety Analysis Report for the Holtec International Storage, Transport, and Repository Cask System (HI-STAR 100 System). Rev. 1. HI-2012610.
Docket No. 72-1008. Marlton, NJ: Holtec International. 2002.
Pacific Gas and Electric Company. Humboldt Bay ISFSI Safety Analysis Report.
Amendment 1. Docket No. 72-27. Avila Beach, CA: Pacific Gas and Electric Company. 2004a.
Pacific Gas and Electric Company. Response to NRC Request for Additional Information for the Humboldt Bay Independent Spent Fuel Storage Installation Application (TAC No. L23683). Letter (October 1). HIL-04-007. Avila Beach, CA: Pacific Gas and Electric Company. 2004b.
Pacific Gas and Electric Company. Response to NRC Request for Additional Information for the Humboldt Bay Independent Spent Fuel Storage Installation Application.
Letter (April 8). HIL-05-003. April 5, 2005. Avila Beach, CA: Pacific Gas and Electric Company. 2005.
U.S. Nuclear Regulatory Commission. NUREG-1567, Standard Review Plan for Spent Fuel Dry Storage Facilities. Washington, DC: U.S. Nuclear Regulatory Commission. 2000.
xviii U.S. Nuclear Regulatory Commission. Holtec International HI-STAR 100 Cask System Safety Evaluation Report. Amendment 2. Docket No. 72-1008. Washington, DC: U.S.
Nuclear Regulatory Commission. 2001a.
U.S. Nuclear Regulatory Commission. 10 CFR Part 72 Certificate of Compliance No.1008, Amendment 2, for the HI-STAR 100 System Dry Cask Storage System.
Docket No. 72-1008. Washington, DC: U.S. Nuclear Regulatory Commission. 2001b.