M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design...
Transcript of M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design...
![Page 1: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/1.jpg)
7U.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
Briefing on DesignAcceptance Criteria
R.W. Borchardt
Executive Director for Operations
November 5, 2010
![Page 2: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/2.jpg)
<?•U.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
Design AcceptanceCriteria
Thomas A. Bergman
Director, Division of Engineering
Office of New Reactors
November 5, 20 10
![Page 3: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/3.jpg)
Agenda
* Recent developments
* Background on design acceptancecriteria (DAC)
" DAC and digital instrumentation andcontrols (l&C)
" DAC closure process
" Conclusions
3
![Page 4: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/4.jpg)
ACRS Letter August 9, 2010
• Underlying concerns with DAC- Leaving DAC open until post-Combined
License (COL)- Relationship between level of design
detail and safety- DAC lack specificity and over-used
- Digital I&C systems have changed sinceDAC conceived
- Require expertise and judgment to close
4
![Page 5: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/5.jpg)
ACRS Letter (cont'd)
* Recommendation 1- Expertise required for DAC inspections
- Independent assessment by A CRS
* Recommendation 2Limit DAC resolved post-COL issuance
Consistent scope and depth of evaluationregardless of when DAC closed
5
![Page 6: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/6.jpg)
Staff Response- October 7, 2010
" Recommendation 1Agree technical expertise requiredPropose role for A CRS in DA C closureconsistent with past practice
* Recommendation 2- Agree preferable to close DAC early- Agree to consistent scope and depth of
evaluation
6
![Page 7: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/7.jpg)
Staff Response (cont'd)
* Assessment of other issues:- Safety finding made on entire
application, not just DAC- Continue to allow use of DAC where
appropriate
- Use technical expertise and soundprocedures to verify DAC implementation
7
![Page 8: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/8.jpg)
DAC Policy
• Consistent over past 20 years- DAC should be objective- Design certification, including one that
relies on DAC, is final safetydetermination
- Additional design detail developed tosatisfy DAC will not alter safetyconclusion
- Limited to a few areas* DAC policy periodically reaffirmed
8
![Page 9: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/9.jpg)
Use of DAC for Digital I& C
" Used in all four certified designs
* Used in all but one designcertification under review
* Design flexibility is desirable
" Use appears to be declining
" Newer designs may not be amenableto DAC
9
![Page 10: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/10.jpg)
DAC Closure VerificationProcess
* Verify completion of the licensee'sactivities to meet DAC
* Resultant design must meet both:- Acceptance criteria in DAC- Licensing basis
10
![Page 11: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/11.jpg)
DAC Inspections
• All DAC are inspected
* Use inspection procedures developedspecifically for DAC
" Use subject matter experts for DACinspections
* Digital I&C inspection proceduresbeing tested with South TexasProject (STP) applicant
11
![Page 12: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/12.jpg)
Staff Proposal to A CRS
* ACRS involvement in inspectionprogram for DAC- Similar to approach for Reactor
Oversight Process (ROP)
- Discuss strategy for program
- Review inspection procedures- Review first implementation of STP
12
![Page 13: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/13.jpg)
Conclusion
* Safety finding made on entireapplication, not just DAC
" Continue to allow use of DAC whereappropriate
" Use technical expertise and soundprocedures to verify DACimplementation
13
![Page 14: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/14.jpg)
Acronyms
* ACRS - Advisory Committee onReactor Safeguards
" COL - Combined License" DAC - Design Acceptance Criteria" I&C - Digital Instrumentations and
Con trots* ROP- Reactor Oversight Process" STP- South Texas Project
14
![Page 15: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/15.jpg)
U.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
ACRS MEETING WITHTHE U.S. NUCLEAR
REGULATORYCOMMISSION
November 5, 2010
![Page 16: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/16.jpg)
I U.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
Overview
&ad•rMKhahk
![Page 17: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/17.jpg)
Accomplishments• Since our last meeting with the
Commission on June 9, 2010, weissued 15 Reports:
* Topics:- Closure of DAC for New Reactors
- Draft Final Rule for Risk-Informed Changes toLOCA Technical Requirements (10 CFR50.46a)
- Mixed Oxide Fuel Fabrication Facility
- Application to Amend the Certified ABWRDesign to Incorporate the AIA Rule
- Long-term Core Cooling for the ESBWR3
![Page 18: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/18.jpg)
* Topics (cont.):- Closure Options for GSI-191- Final SER Associated with the
ESBWR Design CertificationApplication
- SER Related to the South TexaProject COLA Referencing theCertified ABWR Design
- Risk-informed Regulatory Guidfor New Reactors
- Digital I&C Interim Staff GuidiLicensing Process (ISG-6)
IS
vance
mnce on
4
![Page 19: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/19.jpg)
* Topics (Cont.):Final SERs Associated with the LicenseRenewal Applications for:" Cooper Nuclear Station" Duane Arnold Energy Center
Regulatory Guides* RG1.216, Containment Structural
Integrity Evaluation for InternalPressure Loadings Above Design-Basis Pressure
* RG 3 74, Guidance for Fuel CycleFacility Change Processes
Standard Review Plan, NUREG 1520,Fuel Cycle Facility License Applications
5
![Page 20: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/20.jpg)
![Page 21: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/21.jpg)
License Renewal
• Completed review of Cooper andDuane Arnold
* Completed interim reviews and willperform final review of Kewaunee,Palo Verde, and Hope Creek
* Will perform interim and final reviewsof Crystal River, Salem, DiabloCanyon and Columbia in CY 2011
* Will review updates to the GALLReport and associated SRP
7
![Page 22: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/22.jpg)
Power Uprates
• Will review the Nine Mile Point andPoint Beach Extended Power UprateApplications
* Will review associated topicalreports such as:
- RAMONA5-FA, "'A Computer Program forBWR Transient Analysis in the TimeDomain"Supplements to NEDC-33173P-A,"Applicability of GE Methods toExtended Operating Domains"
8
![Page 23: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/23.jpg)
![Page 24: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/24.jpg)
IU.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
ABWR Aircraft ImpactAssessment
Said Abdel-Khalik
![Page 25: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/25.jpg)
Aircraft Impact Assessment
* New nuclear power plantapplicants must perform an aircraftimpact assessment (AIA - 10 CFR50m150)
* AIA does not need to be submittedto NRC, but will be subject toinspection by the NRC
11
![Page 26: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/26.jpg)
* Realistic analyses to identify andincorporate design features andfunctional capabilities needed toshow that, with reduced use ofoperator action:- Reactor core remains cooled or
containment remains intact
- Spent fuel cooling or spent fuel poolintegrity is maintained
12
![Page 27: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/27.jpg)
ABWR Amendment
* STP Application to amend ABWRdesign to address AIA submitted onJune 30, 2009
* Future COL applicants can addressthe requirements of 10 CFR 50-150by referencing amended ABWRstandard design
13
![Page 28: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/28.jpg)
* ACRS Reviewed:- AIA made available by the applicant- Associated safety evaluation and
inspection report
* Review process to be followed forother design centers
14
![Page 29: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/29.jpg)
September 20, 2010 ACRS Report" Staff inspection of the applicant's
AIA was thorough - maintainingsame personnel with high-levelskill in reviewing the applicationand performing the inspectionsignificantly enhanced quality
* The application and SER areacceptable subject to satisfactoryclosure of the issues identified inthe Notice of Violation & ourRecommendation
15
![Page 30: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/30.jpg)
September 20, 2010 ACRS Reporti The staff should ensure that the
applicant demonstrates that thetemperature within the fire-protectedarea where the AFI system instrumentrack is to be located will not exceed theinstruments' environmental qualificationconditions
* The staff should ensure that theassumptions and initial conditionscredited in the applicant's AIA areproperly incorporated into the amendedDCD
16
![Page 31: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/31.jpg)
September 20, 2010 ACRS Reporti The staff should ensure that COL
applicants referencing thisamendment have an appropriateprocess to assure the reliability ofthe AFI system
• The staff should complete thelessons-learned review to identifyany deficiencies in the AIAInspection Procedure and theindustry AIA methodology
17
![Page 32: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/32.jpg)
$~US.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
Risk-Informed Changesto Loss-of-Coolant
Accident TechnicalRequirements (§ 50.46a)
William J. Shack
![Page 33: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/33.jpg)
Bacakground* In March 2003, the Commission
approved the staff's recommendationsrelated to possible changes to LOCArequirements and directed the staff toprepare a proposed rule (§ 50.46a) thatwould provide a risk-informedalternative maximum break size
" ACRS Nov. 16, 2006, letterrecommended that the 2006 version ofthe proposed rule not be issued
" The staff further met with ACRS in May2009 and SeptemberlOctober 2010
19
![Page 34: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/34.jpg)
Overview of the - 50.46a Rule" ECCS Analysis Requirements
" Breaks < Transition break size(TBS)-No change from current §50.46
* Breaks > TBS- No single failure assumption
- Credit for offsite power
- Credit for non-safety equipment
- Alternative metrics for "coolablegeometry" may be used, if justified
20
![Page 35: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/35.jpg)
Overview of the § 50.46a - Cont.Risk-Informed Acceptance Criteria
* For changes submitted for NRCreview-,"very small" cumulative risk increase
* For self-approved changes- "minimal" risk increase
- §50.59 is satisfied
* For all changes- defense-in-depth
- safety margins
- monitoring program21
![Page 36: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/36.jpg)
ACRS Letter November 16, 2006, onNeeded Revisions to Proposed Rule
* Needed to strengthen theassurance of defense in depth forbreaks beyond the transition breaksize (TBS)
* Magnitude of the increases in riskthat could occur due to changesthat did not require prior NRCapproval inconsistent with usualRG 1.174 guidance
22
![Page 37: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/37.jpg)
ACRS Letter November 16, 2006,on Needed Revisions to ProposedRule
" Needed to address revised 50.46(b)guidance for cladding failure
* Needed to perform plant-specificanalyses to assure applicability ofNUREG-1829 and NUREG-1903results on transition break size
23
![Page 38: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/38.jpg)
Resolution of ACRS Commentsin Draft Final Rule
" Requires licensees submit thecodes used for the analyses ofbreaks beyond the TBS to the NRCfor review and approval
* Process for changes that can bemade without prior NRC approvalhas been revised and is nowacceptable
24
![Page 39: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/39.jpg)
Resolution of ACRS Commentsin Draft Final Rule (cont)
* Rule still reflects current 50.46(b)cladding failure criteria. However,additional research has increasedour understanding and a Notice ofAdvanced Rulemaking has beenpublished and staff acknowledgesrule will have to be revised if50.46(b) is updated. We now find itacceptable to proceed
25
![Page 40: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/40.jpg)
Resolution of ACRS Comments inDraft Final RuleRequires plant specific demonstrationthat results of NUREG-1829 andNUREG-1903 for transition break sizeare applicable
- August 23, 2010, version required onlydemonstration that results on direct breaksizes are applicable
- In response to ACRS comments theSeptember 27, 2010, version was revised toalso require a demonstration that results onindirect break sizes are applicable
26
![Page 41: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/41.jpg)
Resolution of ACRS Commentsin Draft Final Rule (cont)
* With these changes we find DraftFinal Rule 50.46a an acceptablerisk-informed alternative to thecurrent 10 CFR 50.46(a) foroperating reactors
27
![Page 42: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/42.jpg)
Application of Risk-Informed 50.46ato New Reactors" Current version of Draft Proposed Rule is
applicable to new reactors
- TBS determined on a plant-specific basis
" ACRS agrees that improved material selection,water chemistry, and design practices willfurther reduce the likelihood of large LOCAs
* Premature to extend the proposed 10 CFR50.46a to new reactors at this time- Risk profiles are significantly different from
current reactors
- Appropriate risk metrics and riskacceptance criteria are still being developed
28
![Page 43: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/43.jpg)
Application of Risk-Informed 50.46ato New Reactors (Cont)* Risk informed changes should notresult in a significant decrease inthe level of safety otherwiseprovided by the certified design
- Language is consistent with Option 2of recent SECY, but even if approvedby Commission specific guidancewould need to be developed
- Rule should be based on specificguidance rather than a concept notyet clearly defined
29
![Page 44: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/44.jpg)
Application of Risk-Informed50.46a to New Reactors (Cont)* If new reactors are included in thescope of the rule, then therequirement that the adoption ofthe rule should not result in asignificant decrease in the level ofsafety should apply to all risk-informed elements includingdetermination of allowable timewithout capability to mitigate abeyond-transition break size LOCA
30
![Page 45: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/45.jpg)
U.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
MOX Fuel Fabrication
Facility
Dana Powers
![Page 46: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/46.jpg)
Background" Mixed oxide (MOX) .facility beingbuilt for the U.S. DOE by MOXServices, LLC at Savannah RiverSite
* Will convert weapons-grade PuG2
to MOX fuel for use in commercialnuclear power plants
32
![Page 47: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/47.jpg)
Backqround (Cont)" Strategy for processing plutoniumand fabricating fuel is patternedafter system used in France
" Builds upon substantial U.S.experience with use of PUREXprocess
* MOX process is simpler, no largeinventory of fission and neutroncapture products
33
![Page 48: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/48.jpg)
Background (Cont).* NRC review process involves twostages:
-Construction Authorization Request
-License to possess and use specialnuclear materials
34
![Page 49: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/49.jpg)
ACRS Report, February 24, 2005ACRS previously reported onSafety Evaluation of ConstructionAuthorization Request
highlighted the need for the licenseapplication to address criticality,hydroxylamine nitrate, the "red off'phenomena, and glove box fires
35
![Page 50: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/50.jpg)
ACRS Report, September 27, 2010• Recent review of safety strategies
revealed no deficiencies- Adequate shielding and filtration to
protect the public
Uses practices that have been provedeffective
Had gone beyond Defense NuclearFacilities Safety Board recommendations
36
![Page 51: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/51.jpg)
ACRS Report, September 27, 2010(Cont)* The Staff has prepared an adequate
Safety Evaluation Report for theMixed Oxide Fuel Fabrication Facilityand the report should be issued
* The proposed facility can beconstructed, operated, andmaintained with no undue risk to thepublic health and safety
37
![Page 52: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/52.jpg)
Path Forward* Construction of the facility will
be verified by inspection prior togranting a license to possess anduse special nuclear material
* The ACRS will revisit the safetyevaluation of the MOX facility asconstruction approachescompletion
.38
![Page 53: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/53.jpg)
U.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
ESBWR Long-Term CoreCooling
Michael L. Corradini
![Page 54: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/54.jpg)
- On May 8, 2008, the Commissionrequested the ACRS to advisethe staff and Commission on theadequacy of the design basislong-term core cooling approachfor each new reactor designbased, on either its review ofthe design certification or thefirst license applicationreferencing that reactor design
40
![Page 55: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/55.jpg)
• The ESBWR is an advancedlight water reactor design thatuses a direct-cycle powerconversion system driven bynatural circulation in thereactor vessel
41
![Page 56: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/56.jpg)
* A passive ECCS is designed toperform its intended functionwithout the need of emergency ACpower systems for core coolingduring the first 3 days following areactor transient or accident. Thedesign employs IsolationCondensers and a PassiveContainment Cooling System (PCCS)to transport heat to the ultimateheat sink for all accident scenarios.
42
![Page 57: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/57.jpg)
e The ESBWR design has a long-term core cooling mode that isqualitatively different fromcurrent reactors, since itspassive safety systems canrespond to a design basisaccident without recirculationthrough the suppression pool.
43
![Page 58: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/58.jpg)
Schematic of ESBWR Containment
[L NOE)- -:,. .,-GDCS Pool
Ii I- - -- Spillover Pipes
44
![Page 59: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/59.jpg)
* The generic issues that havenormally raised concerns forlong-term core cooling in arecirculation mode for theECCS are not present in thisdesign because of thefollowing:
45
![Page 60: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/60.jpg)
-No fibrous insulation is used inthe plant design, allcontainment surface coatingsare qualified, and no complexwater chemistry is presents
46
![Page 61: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/61.jpg)
- The debris which reaches thesuppression pool is not transportedto the PCCS. The recirculationcooling path for long-term corecooling is wet steam into thePCCS, condensate from there tothe Gravity-Driven Cooling System,and then back to the reactorvessel.
47
![Page 62: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/62.jpg)
Conclusion* ACRS concurs with the staff's
assessment that the regulatoryrequirements for long-term corecooling for design basisconditions have been adequatelymet and this issue can be closedfor ESBWR
48
![Page 63: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/63.jpg)
iU.S.NRCUnited States Nuclear Regulatory Commission
Protecting People and the Environment
Closure of DesignAcceptance Criteria for
New Reactors
Dennis C. Bley
![Page 64: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/64.jpg)
ACRS Report, August 9, 20101. DAC closure requires expertise,
judgment, and interpretation. Itshould be performed by NRC staffexperts with an independentassessment by the ACRS
2. It is preferable that all DAC beresolved no later than the COLstage. However, whether resolvedas part of the COL process or post-COL, proper closure of DAC requiresa consistent scope and depth ofevaluation in accord with our firstrecommendation
50
![Page 65: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/65.jpg)
Background" Statements of Consideration (SOC)
for 10 CFR Part 52 state that EarlySite Permit, Design Certification, andCOL processes do not eliminate anymaterial safety issue fromconsideration, they just move -theirresolutions to earlier review stages
* In essence, NRC cannot allowoperation of a nuclear power reactorunless all material safety issues areresolved
51
![Page 66: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/66.jpg)
Statements of Consideration"The Commission does not believethat it is prudent to decide now, beforethe Commission has even once gonethrough the process of judgingwhether a plant built under acombined license is ready to operate.,that every finding the Commission willhave to make at that point will be cut-and-dried-proceeding according tohighly detailed "objective criteria"entailing little judgment and discretionin their application, and not involvingquestions of 'credibility, conflicts, andsufficiency"'
52
![Page 67: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/67.jpg)
Background" Part 52: conformance with
certified design verified throughITAAC
• Practicalities led staff to developconcept of special kind of ITAACcalled DAC
" DAC, as presently constituted, areclearly among those issues forwhich judgment will be required inorder to reach a finding that theacceptance criteria have beensatisfied
53
![Page 68: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/68.jpg)
History of DAC* SRM on SECY-90-377
"Requirements for DesignCertification under 10 CFR Part52"- Applications for design certification
reflect a design that is completeexcept to accommodate as-procuredhardware characteristics
* 1990 ACRS Report on SECY-90-377-Agreed with process and
recommended that the staff focus thescope on that needed for safety
54
![Page 69: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/69.jpg)
History of DAC* The concept of DAC was
introduced in SECY-92-053, "Use ofDAC During 10 CFR Part 52 DesignCertification Reviews," datedFebruary 19, 1992, and written inresponse to the Commission's SRMon SEC Y-90-3 77, datedNovember 7, 1991- identified need- identified potential pitfalls
55
![Page 70: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/70.jpg)
History of DAC - SECY-92-053" Defined DAC as a set of prescribed
limits, parameters, procedures, andattributes in a limited number oftechnical areas
" DAC were to be objective(measurable, testable, or subject toanalysis using pre-approvedmethods) and were to be sufficientlydetailed to provide an adequate basisfor the staff to make a final safetydetermination regarding the design
56
![Page 71: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/71.jpg)
History of DAC - SECY-92-053
* Recognized that "...although thereis nothing in Part 52 which wouldnecessarily limit the use of DAC,the staff believes that the use ofDAC should be limited"
o "restrictions should be based upona consideration of those designareas affected by rapidly changingtechnologies"
57
![Page 72: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/72.jpg)
ACRS Feb 14, 1992, Report" Supported limited DAC approach
* Carefully defined limits relating toscope and extent of designcoverage should be placed on theuse of DAC
" Use of DAC should be limited tothat portion of each given designfeature where either thetechnology is still evolving or therequired information is unavailablefor good reason
58
![Page 73: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/73.jpg)
ACRS Feb 14, 1992, Report• In any case, DAC should be used
only when it is possible to specifypractical and technicallyunambiguous criteria
" DAC can hide unforeseen systemsinteractions that might beuncovered if an actual design wereavailable
59
![Page 74: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/74.jpg)
ACRS Feb 14, 1992, Report"If DAC are employed extensivelyin lieu of design detail, this wouldplace an additional design burdenon the COL holder and create apossible discontinuity in thedesign and review process thatmay be adverse to safety"
60
![Page 75: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/75.jpg)
History of DAC* Later in the same year ACRS formed
an Ad Hoc Subcommittee on DAC inresponse to a Commission SRMissued on April 1, 1992. Staff andthe ACRS appear to have come toquick agreement on RadiationProtection, Piping Design, andControl Room Design (now part ofHuman Factors Engineering) forABWR DAC. I&C DAC were moretroublesome and never appear tohave been completely resolved
61
![Page 76: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/76.jpg)
ACRS Oct 16, 1992, Report"Finally, we are concerned about thesignificant number of post-designcertification activities associated withthese two DACs - control room design,and I&C. The COL applicant or holderwill be responsible for carrying outthese activities. This will involveextensive future negotiations with thestaff. It will also have the effect ofdiminishing the value of certifieddesigns and seems to us to becontrary to the spirit of 10 CFR Part52" 62
![Page 77: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/77.jpg)
ACRS Oct 16, 1992, Report"We believe that the argument thatthese DACs represent areas ofrapidly changing technology isbeing overplayed by both the staffand GE in justifying the extent towhich the DAC process is beingused"
63
![Page 78: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/78.jpg)
ACRS Expectations" DAC would be limited to the extent
possible and generally closed bythe time of the COL issuance
" For DAC to be closed after COL andbefore fuel load, Staff evaluationof ITAAC used to close DAC wouldbe thorough
" ACRS would be involved in Staffevaluation of DAC closure, at leastfor the first applications
64
![Page 79: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/79.jpg)
Observations for DI&C DAC" DI&C systems for new designs are
highly integrated and pervasive,affecting nearly all plantequipment
* Unanticipated failure modes couldcreate very confusing situationsthat could place the plant or leadoperators to place the plant inunexpected or unanalyzedconfigurations
65
![Page 80: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/80.jpg)
Observations for DI&C DAC" Five keys to reliability of DI&C
-Essential objective design principles:redundancy, independence,determinant data processing &communication, defense-in-depth &diversity
-Subjective attribute, simplicity
* DI&C design can be functionallyspecified and shown to meet theessential criteria regardless of theparts technology
66
![Page 81: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/81.jpg)
Observations for DI&C DAC" Some essential design principles
(e.g., redundancy & defense-in-depth) can be specified infunctional block diagrams in DCDand verified by objective ITAAC
" Some (e.g., determinant dataprocessing) must be confirmed asimplemented in the final design ofthe DI&C systems
67
![Page 82: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/82.jpg)
Observations for DI&C DAC" Despite ability to eliminate many
DI&C DAC from designcertifications or COL applications,most are not planned to beresolved until after COL issuance
" More DAC than necessary
68
![Page 83: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/83.jpg)
Observations for DI&C DAC" Many current DI&C DAC are not
technically unambiguous" Many DI&C DAC are process
oriented, but only an evaluation ofthe complete design can reveal theintricacies of possible interactionsand failures, especially commoncause and other dependent failuremechanisms
69
![Page 84: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/84.jpg)
ACRS Report, August 9, 20101. DAC closure requires expertise,
judgment, and interpretation. Itshould be performed by NRC staffexperts with an independentassessment by the ACRS
2. It is preferable that all DAC beresolved no later than the CombinedLicense (COL) stage. However,whether resolved as part of the COLprocess or post-COL, proper closureof DAC requires a consistent scopeand depth of evaluation in accordwith our first recommendation
70
![Page 85: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/85.jpg)
ACRS Report, October 20, 2010* If applicant provides additional
descriptive information--integratedsystem logic diagrams and detailedfunctional descriptions--reviews wouldbe simpler and safety judgments morerobust
* Lack of sufficient ESBWR DI&Cdesign information led to commitmentto revise DCD with sufficientexpanded functional descriptions andDACIITAAC to support safety finding
71
![Page 86: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/86.jpg)
Path Forward" Several subcommittees are
struggling with DI&C DAC" We are following the work of staff's
Task Working Group on DACClosure
P Subcommittee meeting October 21,2010, staff presented examplesand discussed state of plans forDAC closure
72
![Page 87: M101105B - Meeting w/ACRS/Slides. - NRC: Home …Agenda * Recent developments * Background on design acceptance criteria (DAC)" DAC and digital instrumentation and controls (l&C)"](https://reader034.fdocuments.net/reader034/viewer/2022042410/5f26e8311363437634119626/html5/thumbnails/87.jpg)
Abbreviations
ABWR Advanced Boiling Water ReactorAC Alternating CurrentACRS Advisory Committee on Reactor
SafeguardsAFI Alternate Feedwater InjectionAIA Aircraft Impact AssessmentAPWR Advanced Pressurized-water ReactorAPIO00 Advanced Passive 1000BWR Boiling Water ReactorCAP Containment Accident PressureCFR Code of Federal RegulationsCOL Combined LicenseCOLA Combined License ApplicationCY Calendar YearDAC Design Acceptance CriteriaDC Design CertificationDCD Design Control DocumentDI&C Digital Instrumentation & ControlDOE Department of EnergyECCS Emergency Core Cooling SystemEPR Evolutionary Power ReactorESBWR Economic Simplified Boiling Water
ReactorGALL Generic Aging Lessons LearnedGE General Electric
GSIISAI&CISGITAAC
LOCALTRMOXNRCPCCS
PRAPU02PUREXRGSECYSERSOARCA
SOCSRM
SRPSTPTBS
Generic Safety IssueIntegrated Safety AnalysisInstrumentation & ControlInterim Staff GuidanceInspection, Test, Analysis, AndAcceptance CriteriaLoss of Coolant AccidentLicensing Topical ReportMixed OxideNuclear Regulatory CommissionPassive Containment CoolingSystemProbabilistic Risk AssessmentPlutonium DioxidePlutonium - Uranium ExtractionRegulatory GuideSecretary of CommissionSafety Evaluation ReportState-of-the-Art ReactorConsequence AnalysesStatements of ConsiderationStaff RequirementsMemorandumiMemorandaStandard Review PlanSouth Texas ProjectTransition Break Size
73