ML18253A034
| ML18253A034 | |
| Person / Time | |
|---|---|
| Site: | 05200046 |
| Issue date: | 04/15/2015 |
| From: | Jim Steckel NRC/NRO/DLSE |
| To: | Helen Chang, Yeon Kim Korea Electric Power Corp, Korea Hydro & Nuclear Power Co, Ltd |
| Lintz M P/NRO/415-4051 | |
| References | |
| Download: ML18253A034 (7) | |
Text
Page 1 U.S. NUCLEAR REGULATORY COMMISSION REGULATORY AUDIT OF PROBABILISTIC RISK ASSESSMENT, SEVERE ACCIDENT EVALUATION, AND RELIABILITY ASSURANCE PROGRAM AS PART OF THE APR1400 DESIGN CONTROL DOCUMENT APR1400 DESIGN CERTIFICATION Docket No.52-046 AUDIT PLAN APPLICANT:
Korea Hydro and Nuclear Power Co., Ltd. (KHNP) and Korea Electric Power Corporation (KEPCO)
APPLICANT CONTACTS:
Yunho Kim (KHNP)
Harry Chang (KHNP)
DURATION:
Part 1 (at NRC Headquarters)
April 15, 2015, 1:00 p.m. - 5:00 p.m.
Part 2 (Follow-up audits at NRC Headquarters, via KHNPs electronic reading room)
Various times from establishment of electronic reading room through April 2017 when the staff will examine probabilistic risk assessment (PRA), severe accident (SA) evaluation, and reliability assurance program (RAP) documents remotely.
LOCATION:
NRC Headquarters Two White Flint North 11545 Rockville Pike Rockville, MD 20852-2738 AUDIT TEAM:
Lynn Mrowca (NRO/SPRA Branch Chief)
Donnie Harrison (NRO)
Robert Roche (NRO)
James Steckel (NRO, Project Manager)
Page 2 I.
BACKGROUND KHNP and KEPCO submitted by a letter dated December 23, 2014, to the U.S. Nuclear Regulatory Commission (NRC) a Design Control Document (DCD) for its Design Certification (DC) application of the Advanced Power Reactor (APR) 1400 design, accessible by Agencywide Documents Access and Management System (ADAMS) Accession No. ML15006A059. The NRC staff initiated this design certification review on March 9, 2015. To facilitate the NRC staffs evaluation of PRA, SA, and RAP information and to complete its safety review of APR1400 DCD Chapters 19 and 17.4, the staff is planning an audit which includes:
Part 1: A half-day regulatory audit, which will be carried out at the NRC Headquarters, on the afternoon of April 15, 2015 to examine the at-power and low-power and shutdown PRA (including Level 1 and Level 2 internal events, internal floods, internal fires), external events, PRA-based seismic margin assessment (SMA), PRA-related information (i.e., RAP list), and SA evaluation. Part 1 of the audit would include an orientation of these materials and a demonstration of the software (SAREX and FTREX) used to model and quantify the APR1400 PRA, by a member of the KHNP staff.
Part 2: Follow-up audits via KHNPs electronic reading room, from establishment of the electronic reading room through April 2017, which will be carried out at the NRC Headquarters, to continue examining the PRA, PRA-based SMA, external events risk evaluation, key sources of uncertainty/assumptions, uncertainty and sensitivity analyses, importance rankings, SA evaluation, PRA maintenance and upgrade, and RAP. The PRA maintenance/update program including process for assessment of design changes for potential impact on the PRA will also be audited.
II.
PURPOSE The purpose of this audit is for the staff to: (1) gain an understanding of APR1400 PRA, SA and RAP development to reach a reasonable assurance finding, (2) review related documentation and non-docketed information to evaluate conformance with the SRP or technical guidance, and (3) evaluate the quality and programmatic control process/procedures used by KHNP for PRA and RAP.
III.
REGULATORY AUDIT BASIS An audit is needed to evaluate and identify detailed information related to the applicants submittal in direct support of the safety conclusions that need to be made regarding APR1400 DCD Chapters 19 and 17.4.
10 CFR 52.47(a)(27) states that a DC application must contain a final safety analysis report (FSAR) that includes a description of the design-specific PRA and its results.
The NRC staff must have sufficient information to ensure that acceptable risk and adequate assurance of safety can be documented in the NRC staffs safety evaluation report (SER).
Page 3 IV.
REGULATORY AUDIT SCOPE The specific scope of this audit will include reviewing the following topics:
Level 1 and Level 2 internal events PRA Level 1 and Level 2 internal floods PRA Level 1 and Level 2 internal fires PRA Level 1 and Level 2 low-power and shutdown PRA PRA-based SMA External events risk evaluation PRA maintenance RAP list and process Security target set Severe accident evaluations Risk insights V.
DOCUMENTS/INFORMATION NECESSARY FOR THE AUDIT The following documents are to be made available to the NRC staff:
- 1)
PRA Summary Report, Rev. 0, APR1400-E-P-NR-13001-P
- 2)
All PRA notebooks and documents (including digital I&C notebook)
- 3)
Success Criteria calculations and MAAP and RELAP results supporting these success criteria calculations
- 4)
APR1400 emergency operating guidelines (EOGs)
- 5)
Peer reviews, independent reviews, and self assessments, and peer review resolution evaluation report
- 6)
PRA input to design programs and processes
- 7)
PRA input to the reliability assurance program
- 8)
PRA input to the severe accident mitigation design alternatives
- 9)
Room cooling analysis performed to support PRA development
- 10) Detailed failure modes and effects analysis (FMEA) performed to identify initiating events and support the development of system fault trees
- 11) Procedure(s) used to assess all APR1400 design changes for PRA impact (including documentation that implements the procedure)
- 12) List of sources of uncertainty and key assumptions, which drive the PRA models and results
- 13) KHNP Quality Assurance Program Description (QAPD) for the APR1400 Design Certification, Rev. 4, March 2014, APR1400-K-Q-TR-11005-NP
- 14) RAP implementation procedure and/or instructions
- 15) RAP expert panel meeting minutes/summaries
- 16) RAP corrective actions issued
- 17) Description of calculation of corium spreading on the containment floor and drawings showing spreading area
- 18) CORQUENCH results for MCCI in the reactor cavity sump
- 19) WinMACCS computer code output files for source term categories, STC-3 and STC-19
Page 4
- 20) Calculations of onsite doses for source term categories, STC-3 and STC-19
- 21) Supporting seismic fragility calculations, and basis and justification for assumed HCLPF values (including screened out components)
- 22) Procedure to ensure HCLPF of 1.67 times the CSDRS for equipment on the SEL qualified by seismic qualification tests
- 23) Related to the containment performance goal, supporting deterministic finite element evaluation that meets the Factored Load Category requirements of ASME Code,Section III, Division 2, Subarticle CC-3720
- 24) Documentation of the MAAP model and MAAP calculations used to develop the source terms in DCD Table 19.1-29 on Pages 19.1-391 through 19.1-393
- 25) List of key sources of uncertainty and key assumptions which drive the MAAP calculations and MAAP results
- 26) Verification and validation report (description, attributes, and associated activities for assessing the quality) of software (e.g., SAREX, FTREX, room heatup, etc.,) used to develop APR1400 PRA and SA
- 27) Analyses of Hydrogen Distribution and DDT Potential in the APR1400 during LPSD Severe Accidents, Rev.0, KEPC-LPSD-NRCDC-H2
- 28) Distance from the top of RHR pipe flow area and vortex test procedure
- 29) Containment capacity evaluation on severe accident
- 30) Test report on hot leg levels and shutdown cooling system flow rates
- 31) Reactor cooling pump seal test and probability calculation
- 32) Fragility analysis performed to support PRA-based seismic margin assessment (SMA)
- 33) PRA-based SMA during low power and shutdown Appropriate handling and protection of proprietary information shall be acknowledged and observed throughout the audit.
VI.
SPECIAL REQUESTS The NRC staff requests the following:
Searchable electronic copies of the documents listed above KHNP personnel to provide an overview of the PRA and related documents and a demonstration of the software used to model the APR1400 PRA.
VII.
AUDIT ACTIVITIES AND DELIVERABLES The NRC audit team is expected to consist of twelve individuals covering the technical areas identified in the PRA, SA, and RAP. The task assignments are shown in Table 1. Depending upon how much effort is needed in a given area, NRC team members may be reassigned to ensure adequate coverage of important technical elements.
The NRC staff acknowledges the proprietary nature of the information requested. It will be handled appropriately throughout the audit. While the NRC staff will take notes, the NRC staff will not remove hard copy or electronic files from the audit site(s).
Page 5 An audit report will be generated after completion of the audit and published in the NRCs ADAMS. The audit will assist the NRC staff in the issuance of RAIs (if necessary) for the licensing review of APR1400 DCD Chapters 19 and 17.4 and PRA-related information provided in other chapters and in preparation of the NRC staffs SER.
The agenda for Part 1 of the audit is presented in Attachments A of this audit plan. If necessary, any circumstances related to the conductance of the audit will be communicated to James Steckel (NRC) at 301-415-1026 or James.Steckel@nrc.gov.
Page 6 Table 1 - Reviewer Assignments Technical Elements Reviewers and Assignments Hanh Phan Marie Pohida Tony Nakanishi Odunayo Ayegbusi Courtney St. Peters Hanry Wagage Jason Schaperow Anne-Marie Grady Robert Roche Alissa Neuhausen 1
PRA Quality and Maintenance P
S 2
Use of PRA (ITAAC, security target set, human factor, Technical specifications, etc.)
P S
3 Level 1 - Internal Events
- Accident Sequence
- Success Criteria P
S 4
Level 1 - Internal Events
- Systems Analysis
- Human Reliability
- Data Analysis
- Quantification S
P 5
Level 2 - Internal Events P
S S
6 Level 1 - Internal Floods S
P 7
Level 2 - Internal Floods P
S S
8 Level 1 - Internal Fires S
P 9
Level 2 - Internal Fires P
S S
10 PRA-based SMA P
S 11 SMA Fragility Analysis P
S 12 Other External Events P
S 13 Level 1 - Low-Power and Shutdown PRA
- Internal Events
- External Events P
S 14 Level 1 - Low-Power and Shutdown PRA
- Internal Floods
- Internal Fires S
P 15 Level 2 -Low-Power and Shutdown PRA P
S 16 Severe Accident Evaluations P
S S
17 Containment Performance P
S 18 Reliability Assurance Program S
P 19 Risk Insights S
P P - Primary Responsibility; S - Secondary Responsibility
Page 7 ATTACHMENT A AUDIT AGENDA Part 1 - APR1400 DCD Chapters 19 and 17.4 PRA, SA, and RAP Regulatory Audit April 15, 2015 NRC Headquarters Two White Flint North 11545 Rockville Pike Rockville, MD 20850 Wednesday, April 15, 2015:
1:00 p.m. - 1:15 p.m.
Introduction/Entrance Meeting... [NRC/KHNP]
1:15 p.m. - 2:45 p.m.
Orientation of PRA Models/Documents [KHNP/NRC]
3:00 p.m. - 4:00 p.m. Demonstration of PRA Software [KHNP/NRC]
4:00 p.m. - 4:30 p.m. NRC Staff Caucus... [NRC]
4:30 p.m. - 5:00 p.m. Summary of the Day and Action Items.............................. [NRC/KHNP]