ML18337A215

Clinch River: NRC Staff Full Committee Slides

ML18337A215
Person / Time
Site:	Clinch River
Issue date:	12/03/2018
From:	Allen Fetter, Bruce Musico, Mallecia Sutton NRC/NRO/DLSE
To:
Sutton M
References
Download: ML18337A215 (30)

Text

Mallecia Sutton, Project Manager, NRO/DLSE/LB3 Allen Fetter, Project Manager, NRO/DLSE/LB3 Section 13.3 Emergency Planning Michelle Hart, Technical Reviewer, NRO/DLSE/RPAC Bruce Musico, Technical Reviewer, NSIR/DPR/RLB Presentation to the ACRS Full Committee Clinch River Nuclear Site - Early Site Permit Application (ESPA) Safety Review December 6, 2018

Clinch River Nuclear Site ESP Application Review Overview Tennessee Valley Authority (TVA) submitted an ESPA for the Clinch River Nuclear Site to NRC (May 26, 2016)

Application accepted for docketing and detailed technical review on December 30, 2016. Federal Register Notice on acceptance decision (January 12, 2017)

TVA requested permit approval for a 20-year term along with approval for a plume exposure pathway (PEP) emergency planning zone (EPZ) sizing methodology, 2 major features (onsite) emergency plans, and exemption requests for site boundary and 2-mile PEP EPZs Plant Parameter Envelope (PPE) based on four small modular reactor (SMR) designs 2

Staff Review Staff overview presentation to ACRS on ESP, PPE and Clinch River ESP review schedule (November 15, 2017)

NRC Staffs safety review of the application included 5 audits and 1 inspection, and issuance of 12 request for additional information (RAIs)

(comprising 50 questions)

Staff completed all Advanced Safety Evaluations (ASEs) with no Open Items and presented to ACRS Subcommittee (May 15, 2018 -

November 14, 2018)

ASEs include 42 combine license application (COL) Action Items and 8 Permit Conditions Staff cooperated with U.S. Army Corps of Engineers, consulted with Federal Emergency Management Agency, and engaged with U.S.

Department of Energy, Tennessee Department of Environment and Conservation, the U.S. Geological Survey and the Tennessee Emergency Management Agency 3

Approving an ESP Site without a Selected Reactor Technology

• ESP Plant Parameter Envelope (PPE) values can bound a variety of reactor technologies rather than one specific technology (an amalgam of values representing a surrogate nuclear plant)

• The PPE values are bounding criteria used by staff to determine the suitability of an ESP site for construction and operation of a nuclear plant

• In the combined license application (COLA), when a specific technology is identified, the PPE values are compared to those of the selected technology. If design parameters of the selected technology exceed bounding ESP PPE values, additional reviews are conducted to ensure that the site remains suitable from a safety and environmental standpoint for construction and operation of the selected nuclear plant technology ESP Plant Parameter Envelope 4

ESP Plant Parameter Envelope (contd)

TVA used the following reactor designs to develop the Plant Parameter Envelope (PPE):

• BWXT mPower SMR, 530 megawatts thermal (MWt) (180 megawatts electric (MWe)

• NuScale SMR, 160 MWt (50 MWe)

• Holtec SMR-160, 525 MWt (160 MWe)

• Westinghouse SMR, 800 MWt (225 MWe)

TVAs PPE is based on construction and operation of two or more SMRs at the Clinch River Nuclear Site with a maximum site nuclear generating capacity of 2420 MWt (800 MWe) 5

Safety Evaluation Sections Chapter Sections Accession Numbers 2.1 Geography and Demography ML18102B203 2.2 Nearby Industrial Transportation and Military Facilities ML18102B203 2.3 Meteorology ML18277A224 2.4 Hydrologic Engineering ML17289B151 (NP)

ML18290A685 (P) 2.5.1 Geologic Characterization ML17289B252 2.5.2 Vibratory Ground Motion ML17289B253 2.5.3 Surface Deformation ML17289B254 2.5.4 Stability of Subsurface Materials and Foundations ML17289B255 2.5.5 Stability of Slopes ML17289B255 3.5.1.6 Aircraft Hazards ML18102B150 11.2 & 11.3 Radioactive Waste Management ML17289A625 13.3 Emergency Planning ML17291A052 15.0.3 Radiological Consequences of Design Basis Accidents ML18102B149 17.5 Quality Assurance Program Description ML17291A547 6

TVA provided adequate information pertaining to;

• the site setting and boundaries

• Exclusion Area Boundary (EAB) authority and control

• current and future population projections

• low population zone (LPZ) distance, population center distance and population density Based on the information provided by the applicant and staffs independent confirmatory evaluation, the staff found the information to be acceptable as it meets the requirements of 10 CFR 100.20 Section 2.1 Geography and Demography 7

TVA adequately identified potential sources and hazards in site vicinity TVA adequately evaluated potential accidents pertaining to explosions, vapor cloud explosions, hazardous/toxic chemical vapors, and fires Based on the information provided by the applicant and staffs independent confirmatory evaluation, the staff found the information to be acceptable as the information meets the guidance provided in NUREG-0800 Section 2.2.1-2.2.2 Section 2.2 Nearby Industrial, Transportation, and Military Facilities 8

Site characteristics related to extreme weather (hurricane and tornado winds, winter precipitation, temperature and humidity extremes) are acceptable Onsite meteorological monitoring system provides adequate data to represent meteorological dispersion conditions Site characteristics related to Short-Term (Accident) and Long-Term (Routine Release) dispersion estimates (X/Q and D/Q values) are acceptable Based on the information provided by the applicant, the staff found all regulatory requirements have been satisfied with no open items Section 2.3 - Meteorology 9

Short-Term (Accident) X/Q Values

- Exclusion Area Boundary (335 meters)

- Low Population Zone (1609 meters)

Based on PAVAN Atmospheric Dispersion Model

- Gaussian model

- Various time averaging periods

• 0-2 hr @ EAB

• 0-8 hr, 8-24 hr, 1-4 days, and 4-30 days @ LPZ

- Intended to represent dispersion conditions that are exceeded no more than 5% of the time Used to demonstrate compliance with 10 CFR 52.17(a)(1)(ix) dose guidelines for design basis accidents

- 25 rem at the EAB for any 2-hour period following the onset of the release

- 25 rem at the outer boundary of the LPZ for the duration of the release Short-Term (Accident) X/Q Values 10

Section 2.4 Hydrologic Engineering TVA proposed adequate site characteristics and bounding design parameters for inclusion in the ESP Design basis flood and maximum groundwater levels, and the accidental release dose estimate meet regulatory requirements Staff concludes that applicant meets ESP regulatory requirements associated with hydrologic engineering 11

Geologic Site Characterization (Section 2.5.1) - No tectonic features with the potential for adversely affecting suitability of the site occur in the site region, site vicinity, site area, or at the site location Vibratory Ground Motion (Section 2.5.2) - Applicants ground motion response spectrum adequately represents the regional and local seismic hazards, and accurately includes the potential effects of local site-specific subsurface properties Surface Deformation (Section 2.5.3) - Negligible potential exists for tectonic surface deformation at the site. Karst is the primary potential hazard for non-tectonic surface deformation that could adversely affect the site Stability of Subsurface Materials and Foundations (Section 2.5.4) - Applicant adequately determined the engineering properties of subsurface materials at the site, and properly evaluated the stability of subsurface materials and foundations based on results of field and laboratory tests and state-of-the-art methodology Stability of Slopes (Section 2.5.5) - Applicant provided necessary information on site topography and geologic conditions, and adequately described characteristics of slopes at the site Section 2.5 Geology, Seismology and Geotechnical Engineering 12

For site suitability, aircraft accidents should not lead to radiological consequences in excess of the exposure guidelines of 10 CFR 50.34(a)(1) with a probability of occurrence greater than about 10-7 per year The applicant determined an aircraft crash probability of 7.53 x 10-7 per year from two nearby airways not associated with local airport operations The staff conservatively estimates a potential aircraft crash probability of 1.5 x 10-8 per year (bounding the applicants probability), assuming all flights within 10 miles of the site follow the two airways passing near the site Staff finds that the applicants approach is reasonable and the probability value is acceptable Section 3.5.1.6 Aircraft Hazards 13

Chapter 11 Radioactive Waste Management, Sections 11.2.3 and 11.3.3 Applicants methodology to develop the normal PPE liquid and gaseous effluent release source terms for use in calculating offsite doses is reasonable Normal PPE liquid and gaseous effluent release concentrations meet the unity rule in 10 CFR Part 20, Appendix B, Table 2, Columns 1 and 2 Offsite doses from normal PPE liquid and gaseous effluent release source terms meet the design objectives in 10 CFR Part 50, Appendix I, Sections II.A, II.B, and II.C; Environmental Protection Agencys (EPA) radiation standards in 40 CFR Part 190, as implemented under 10 CFR 20.1301(e);

and public dose limit in 10 CFR 20.1301 Reactor designs falling within the normal PPE effluent release source terms and offsite doses for the Clinch River Nuclear Site are without undue risk to public health and safety 14

Evaluation of the radiological consequences of postulated design basis accidents (DBAs) is based on the PPE accident source term for DBA isotopic releases to the environment (in lieu of specific plant design information) in conjunction with site characteristic short term (accident) atmospheric dispersion factors The same dose criteria are used for siting and postulated accident dose analysis requirements:

The evaluation must determine that:

1.

An individual located at any point on the boundary of the exclusion area for any 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> period following the onset of the postulated fission product release would not receive a radiation dose in excess of 25 rem total effective dose equivalent (TEDE).

2.

An individual located at any point on the outer boundary of the low population zone, who is exposed to the radioactive cloud resulting from the postulated fission product release (during the entire period of its passage) would not receive a radiation dose in excess of 25 rem TEDE Staff concluded that the applicants analysis meets the dose criteria specified, and the PPE includes the bounding accident releases for the determination Chapter 15 Accident Analysis 15

NRC Staff identified one RAI, March 9, 2018 NRC Staff conducted Quality Assurance Implementation Inspection, April 16-20th 2018.

TVA issued Nuclear Quality Assurance Plan, Revision 36; May 8, 2018 Staff concluded that the applicants quality assurance program description for the Clinch River Nuclear site ESP application meets the requirements of 10 CFR Part 50, Appendix B and 10 CFR 52.17(a)(1)(xi) and (xii)

Section 17.5 Quality Assurance Program Description 16

13.3 Emergency Planning The ESPA requested review of 3 key areas, which consist of:

Plume exposure pathway (PEP) emergency planning zone (EPZ) sizing methodology 2 major features (onsite) emergency plans (ESPA Part 5)

- ESPA Part 5A reflects a site boundary PEP EPZ

- ESPA Part 5B reflects a 2-Mile PEP EPZ (including an ETE) 25 Exemption Requests (ESPA Part 6)

- 2 exemption requests (applicable to both the site boundary and 2-mile PEP EPZs)

- 23 exemption requests address portions of 10 CFR 50.47(b) and Appendix E to 10 CFR Part 50 for offsite emergency planning (EP) related to the site boundary PEP EPZ only 17

25 Exemption Requests (EP) 10 CFR 50.33(g) & 50.47(c)

- 2 requests for exemptions from the 10-mile PEP EPZ requirement 10 CFR 50.47 & Appendix E to 10 CFR Part 50

- 23 requests for exemption from the emergency planning requirements associated with offsite emergency planning

• State & local emergency plans

• Public alert & notification

• Evacuation Time Estimate (ETE)

• Offsite exercises 18

Basis for Acceptance The ESPA provides a basis for the establishment (in the COLA) of either a Site Boundary or 2-mi PEP EPZ, which maintains the same level of protection (i.e., dose savings in the event of a radiological emergency) in the environs of the Clinch River Nuclear Site as that which exists in the basis for a 10-mi PEP EPZ 19

Combined License Application Upon issuance of the ESP, the applicant acquires approval, with conditions, of:

- The PEP EPZ sizing methodology

- The 2 major features emergency plans (site boundary/2-mile PEP EPZ)

- The 25 requested exemptions A COLA that incorporates by reference the ESP must:

- Identify the chosen SMR technology for the Clinch River Nuclear site

• Demonstrate that the EPZ sizing methodology supports either the site boundary or 2-mile PEP EPZ

- Provide a complete & integrated emergency plan

• 2-mile PEP EPZ must provide onsite & offsite emergency plans

• site boundary PEP EPZ must provide an onsite emergency plan

- Address all 16 COL Action Items and 4 Permit Conditions 20

EPZ Size Determination in COLA COL Action Item 13.3-1 (reflects ESPA Part 2 Section 13.3.3.1.4)

- Identify chosen SMR technology & major features emergency plan

- Provide detailed information that shows the ability of the SMR to meet the chosen PEP EPZ

- The selected SMR technology must meet the EPA early phase protective action guide (PAG)

Permit Condition 1

- Provide detailed information to demonstrate that the accident release source term information for the PEP EPZ size determination analysis using the selected SMR design is bounded by the non-design-specific plant parameter source term information used in the analysis supporting the exemption requests (ASER Table 13.3-1)

- Based on non-design-specific bounding 4-day accident release source term that meets EPZ size criteria 21

TVA PEP EPZ Size Methodology Technical Criteria PEP EPZ should encompass those areas in which projected dose from DBAs could exceed the EPA early phase PAG PEP EPZ should encompass those areas in which consequences of less severe core melt accidents could exceed the EPA early phase PAG PEP EPZ should be of sufficient size to provide for substantial reduction in early health effects in the event of more severe core melt accidents 22

TVA PEP EPZ Size Methodology SSAR Section 13.3.3.1 Accident scenario selection

- Use bounding DBA from COLA Final Safety Analysis Report Chapter 15

- Use COLA site-and design-specific probabilistic risk assessment to categorize severe accident scenarios

• All modes, internal and external events, applicable fuel handling and spent fuel pool accidents, multi-module considerations

• Assess all sequences with mean core damage frequency (CDF) > 10-8 per rx-yr

• More probable, less severe core melt scenarios

- Mean CDF > 10-6 per rx-yr

- Intact containment

• Less probable, more severe core melt scenarios

- Mean CDF > 10-7 per rx-yr

- Includes containment bypass or failure Determine source term releases to atmosphere Calculate dose consequences at distance from plant Determine PEP EPZ size that meets the dose-based criteria 23

TVA Dose-Based PEP EPZ Size Criteria Dose to individual from exposure to the airborne plume during its passage and to groundshine, using average atmospheric dispersion characteristics for site Staff expects the applicant may use the calculation tools used for severe accident consequence analysis in environmental report DBA and more probable, less severe accidents 1 rem TEDE from 96-hr exposure Lower end of dose range EPA PAG for early phase protective actions (e.g.,

evacuation and sheltering)

Verify that dose consequences do not exceed the EPA PAG beyond the site boundary (within owner controlled area) and 2-mile PEP EPZs Less probable, more severe accidents Calculate the distance at which the conditional probability to exceed 200 rem whole body from 24-hr exposure exceeds 10-3 per rx-yr Acute dose at which radiation-induced early health effects may begin to be noted (e.g., nausea)

Verify that the PEP EPZ supports substantial reduction in early health effects 24

Review of PEP EPZ Size Methodology Staff compared TVAs methodology and dose criteria to the study used as technical basis for current 10-mile PEP EPZ requirement (NUREG-0396)

- The features of TVAs methodology are consistent with NUREG-0396

• Considered a range of accidents

• Performed accident consequence analyses

• Determined an area outside of which early protective actions are not likely to be necessary to protect the public from radiological releases The staff concludes that the applicants proposed methodology is reasonable, and consistent with the analyses that form the technical basis for the current regulatory requirement of a PEP EPZ of about 10 miles in radius 25

EP Exemption Plant Parameters TVA developed a non-design-specific accident release source term that would meet the PEP EPZ size criteria to be used as plant parameters (ASER Table 13.3-1)

- Isotopic total release activity over 96 hrs results in TEDE of about 0.9 rem at site boundary

- Same idea as PPE DBA source term to envelope an unknown design

- Referenced in Permit Condition 1 for adoption of EP exemptions 26

Section 13.3 EP Conclusions The staff concludes that:

- The PEP EPZ sizing methodology is acceptable for determining the appropriate size of the PEP EPZ for the Clinch River Nuclear site because it is consistent with the analyses that form the technical basis for the current 10-mile PEP EPZ

- The 2 major features emergency plans are acceptable because they meet the applicable standards of 10 CFR 50.47 and requirements of Appendix E to 10 CFR Part 50

- The exemption requests are acceptable because they are authorized by law, will not present an undue risk to the public health and safety, are consistent with the common defense and security, and special circumstances are present 27

Questions?

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Technical Reviewers Dan Barss Luissette Candelario Yuan Cheng Richard Clement Joseph Giacinto Michelle Hart David Heeszel Michael Mazaika Bruce Musico Kevin Quinlan Nicholas Savwoir Gerry Stirewalt Seshagiri (Rao) Tammara Jenise Thompson Weijun Wang Jason White 29

Acronyms ASE - Advanced Safety Evaluation CFR - Code of Federal Regulations COL - Combined License COLA - Combined License Application CDF - Core Damage Frequency CP - Construction Permit CRN - Clinch River Nuclear DBA - Design Basis Accidents DBF - Design Basis Flood EAB - Exclusion Area Boundary EP - Emergency Planning EPA - Environmental Protection Agency EPZ - Emergency Planning Zone ESP - Early Site Permit ESPA - Early Site Permit Application ETE - Evacuation Time Estimate FRN - Federal Register Notice LOCA - Loss of Coolant Accident LPZ - Low Population Zone NP-Non-Public MWe - Megawatts Electric MWt - Megawatts Thermal NP-Non-Public NRC - Nuclear Regulatory Commission P-Public PAG - Protective Action Guide PEP - Plume Exposure Pathway PPE - Plant Parameter Envelope RAI - Request for Additional Information SER - Safety Evaluation Report SMR - Small Modular Reactor SSCs - Structures, Systems and Components TEDE - Total Effective Dose Equivalent TVA - Tennessee Valley Authority USGS - U.S. Geological Survey 30