ML19092A403
| ML19092A403 | |
| Person / Time | |
|---|---|
| Issue date: | 04/04/2019 |
| From: | Jason Paige NRC/NRR/DLP/PLPB |
| To: | |
| Paige J, NRR/DLP/PLPB, 415-1474 | |
| Shared Package | |
| ML19092A39 | List: |
| References | |
| Download: ML19092A403 (10) | |
Text
April 4, 2019 - Public Meeting on BTP 7-19 Revision
SUMMARY
OF PREVIOUS D3 ASSESSMENTS FOR DIGITAL SYSTEMS (as of March 2019)
Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs)
- Existing Analog DAS for ML030920676 NRC performed a Functions methodology Auto DAS only two protective (56 pages) safety evaluation of (Included voting postulated complete (ATWS) functions: the D3 analysis to functions) failure of all
- Diverse verify adequate functions performed Manual
- DHPIAS diversity for all by entire system Controls to
- DLPIAS analyzed events.
Events were support This was a separate simulated using MOAs submittal, which computer codes. preceded the LAR.
13 out of 17 The SE was updated Non-LOCA functions did not in 2009 to include analyses, used the require evaluation of the same conservative additional DHPIAS. 16 considerations as diverse actuation different events were Oconee the ONS UFSAR capability. analyzed using the analysis. methodology defined in the assessment.
LOCA analyses Analysis results used realistic were placed into five assumptions for categories.
boundary conditions. The staffs evaluation included review of each transient and accident event analyzed in the Oconee UFSAR.
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April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs)
(ML060340449, Approved 2/3/2006)
(11 pages)
(ML090510384, Approved 2/23/2009) (13 pages)
MSFIS Functions The licensee used
- Internal No DAS needed ALS Diversity NRC reviewed the ISG-02, Diversity diversity of Analysis D3 analysis as part and Defense-in- the ALS ALS portion of ML090270428 of the license Depth Issues to platform. system credited (37 pages) amendment, so a evaluate that the for internal separate SE was not internal diversity of diversity. MSFIS D3 prepared.
the ALS platform is Assessment sufficient to address ML090270825 The staffs Wolf Creek CCF. (12 pages) evaluation included review of the ALS The licensee diversity analysis.
evaluated transients (ML090610317, and accidents that Approved required the MSFIS 3/31/2009) (D3 controls for Analysis - 3 pages).
mitigation.
All functions The licensee used Functions No DAS needed ML101100648 NRC performed a performed by the the D3 methodology requiring DAS (78 pages) safety evaluation of existing Eagle 21 described in BTP 7- were allocated to ALS portion of the D3 analysis.
PPS. (Excluded 19. It postulated ALS portion of system credited This was a separate Diablo Canyon SSPS voting hard failure of all the system. for internal submittal which functions). functions performed diversity. preceded the LAR.
by entire system. (ML110480845, Approved 2
April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs)
Signals 4/19/2011) (27 Requiring pages).
Diversity:
- PZR Pressure
- RC Flow
- Containment Pressure PRNMS Functions Limited Scope D3
- MOA No DAS Needed Appendix I of NRC included an analysis performed LAR. evaluation of the D3 in conjunction with MOA functions ML15265A224 analysis in its LAR LAR review. credited. (20 pages) safety evaluation.
Events that credited stability protection functions were analyzed using methodology defined in the assessment.
Complete loss of stability protection Hope Creek was postulated in the analysis.
The NRC staffs evaluation determined that indicators and control functions to be used for performing MOAs were independent and diverse from the digital PRNMS 3
April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs) system. Licensee also demonstrated capability of operators to perform required MOAs within allotted time.
(4 pages, Section 3.4 of SE).
Core Stability Limited Scope D3
- MOA No DAS Needed Section 2.4.1.1 NRC performed an Protection Function analysis performed. of the LAR evaluation of D3 MELLLA-Plus Postulated loss of MOA functions ML18079B140 analysis. This core stability trip credited. (3 pages) evaluation functions due to determined that software CCF. indicators and control functions to be used for performing MOAs were independent and diverse from the Browns Ferry digital PRNMS.
Licensee also demonstrated capability of operators to perform required MOAs within allotted time.
(3 pages, Section 3.2 of the SE.
Amendment in progress).
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April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs)
Core Stability Limited Scope D3
- MOA No DAS Needed Provided as NRC performed an Protection Function analysis performed. response to evaluation of D3 Extended Flow Postulated loss of MOA functions RAIs analysis. This Window (EFW) EFW trip functions credited (4 pages) evaluation due to software determined that CCF. indicators and control functions to be used for performing MOAs were independent Monticello and diverse from the digital PRNMS system. Licensee also demonstrated capability of operators to perform required MOAs within allotted time.
(7 pages).
New Reactors and Design Certifications Unknown what PRA-based analysis N/A (This is
- Auto DAS AP1000 D3 The SER cited the functions were for selecting DAS column is not provided Technical WCAP-13793, analyzed. functions. evaluated for new (FPGA-based Report (39 AP600 reactors because system). pages) System/Event the plant design matrix, which AP1000 DCA basis is being Hardwired system- describes how established so no level manual multiple levels of existing diversity actuation switches defense exist for is credited). also provided on a each type of separate panel. analyzed events.
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April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs)
The DAS was credited as providing the reactor protection functions for every event analyzed in this technical report.
The SER stated that this report is applicable to the AP1000 and therefore the D3 analysis of the AP1000 is acceptable. See Section 7.1.6 of SER (4 pages).
Same as AP1000 PRA-based analysis N/A Same as AP1000 Same as ITAAC closure DCA for selecting DAS AP1000 DCA needed for DAS functions development Vogtle 3&4 (based on AP1000 process activities COL DCA). and outputs and for DAS diversity attributes.
All functions Full D3 analysis N/A
- Automatic A D3 Technical NRC performed an performed by the plant using best estimate diverse Report (78 evaluation of the D3 protection system methods. protection pages) and a analysis. The staffs (PPS), including all RT system (DPS) Coping Analysis evaluation included APR-1400 DC trip functions, SI Technical review of each event (FPGA-based) actuation, containment provided as Report (119 analyzed in the isolation actuation, part of the DAS. pages) were Coping Analysis containment spray The DAS submitted. Technical Report 6
April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs) actuation, main steam includes a and the DAS design isolation, and aux. hardwired to verify adequate feedwater actuation. system-level diversity. (The SE of manual the D3 analysis is Both spurious actuations approximately 30 actuation and loss of switches. pages.)
function were
- Diverse analyzed. Indication System (FPGA-based) provided as part of the DAS.
- For the postulated spurious actuations analyzed, none resulted in a plant response or consequence that created conditions which were not bounded by the plant safety analysis.
The D3 evaluation Full D3 Analysis N/A A triple-redundant A D3 Licensing NRC performed an included all functions using Best Estimate Diverse Protection Topical Report evaluation of the D3 credited in the safety Analysis System is was submitted, analysis. (The SE of ESBWR DC analysis. The provided that which includes a the D3 analysis, evaluation also includes both D3 analysis that including the included potential for follows the potential for spurious 7
April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs) inadvertent (spurious) automatic and guidance of is approximately 21 actuation and the manual functions. NUREG/CR pages).
design features to 6303. This address them, report is 87 including pages.
segmentation of the distributed control system..
All functions Full D3 Analysis N/A No DAS Needed D3 Analysis SER with Open performed by the using Best Estimate (24 pages) Items, but it did not Module Protection Methods. The MPS includes identify any open System (MPS) are evaluation included internal diversity. items for D3 analyzed. The MPS is the sensor block as All postulated assessment. The the only safety-related well as the safety digital CCFs of SER with open items digital I&C system. block. identical portions evaluation on the D3 of the MPS assessment, Both spurious (including including the actuation and loss of sensors) spurious actuation function were concurrent with a analysis (D3 portion NuScale DCA analyzed. DBE did not is 21 pages).
(Review in violate the primary Progress) coolant pressure boundary, or result in radiation release exceeding 10 CFR Part 100 limits.
For the postulated spurious actuations analyzed, none resulted in a plant 8
April 4, 2019 - Public Meeting on BTP 7-19 Revision Analytical What existing D3 Licensing Scope of D3 Approach Diversity was Outcomes Scope of NRC Assessment Action Assessment (Type of analysis: Best Credited? (i.e., Identified need for Review (i.e., Design functions estimate, bounding (Use of Auto or new or additional Submittal (Safety Evaluation page (LAR or DC) included) consequences, human Manual, DAS or diverse methods) (D3 Analysis page count) factors) count)
MOAs) response or consequence that created conditions which were not bounded by the plant safety analysis.
TOPICAL REPORTS Precluded CCF from Westinghouse Existing No DAS Needed Section 3.6 of Analysis further consideration performed an functional the SE is less demonstrated that by test and analysis analysis of all the diversity was The analyses that one page not all possible showing that all circuits on the maintained. and testing were long and sequences were applicable functions CPLD using the sufficiently evaluates the tested. Further, it were thoroughly appropriate vendor rigorous and D3 included additional tested. supplied tool, with complete to assessment information that the intention of allow the NRC that was show the untested SSPS demonstrating that staff to conclude included in sequences did not Topical the testing that that no further Section 6, 7, & need to be tested Report was already consideration of 9.4 of the since they were performed (See CCF. topical report. functionally TR Section 5) met irrelevant.
the testability criteria in BTP 7-19, Section 1.9(2),
to eliminate consideration of CCF.
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