ML031840460
| ML031840460 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/01/2003 |
| From: | Olshan L NRC/NRR/DLPM/LPD2 |
| To: | |
| References | |
| TAC MB8086, TAC MB8087, TAC MB8088 | |
| Download: ML031840460 (26) | |
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NRC FORM 658 US. NUCLEAR REGULATORY COMMISSION TRANSMITTAL OF MEETING HANDOUT MATERIALS FOR IMMEDIATE PLACEMENT IN THE PUBLIC DOMAIN This form is to be filled out (typed or hand-printed) by the person who announced the meeting (i.e., the person who issued the meeting notice). The completed form, and the attached copy of meeting handout materials, will be sent to the Document Control Desk on the same day of the meeting; under no circumstances will this be done later than the working day after the meeting.
Do not Include proprietarymaterials.
DATE OF MEETING The attached document(s), which was/were handed out in this meeting, is/are to be placed 07101t2003 in the public domain as soon as possible. The minutes of the meeting will be issued in the near future. Following are administrative details regarding this meeting:
Docket Number(s) 50-269,50-270,50-287 Plant/Facility Name OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 TAC Number(s) (if available) MB8086, MB8087, MB8088 Reference Meeting Notice JUNE 6,2003 Purpose of Meeting (copy from meeting notice) TO DISCUSS DEFENSE-IN-DEPTH AND DIVERSITY ANALYSIS ASSOCIATED WITH DIGITAL UPGRADE OF RPSAESPS NAMIE OF PERSON WHO ISSUED MEETING NOTICE TlIE L. N. OLSIIAN PROJECT MANAGER OFFICE NRR DIVISION DLPM BRANCH PDII-1 Distribution of this form and attachments:
Docket File/Central File PUBLIC 6 ((91999)
. .199 .RNE ON E_EPE ,hi .om.u .eige.sn .no NRCNR =FR FORM 658 PRINTED ON RECYCLED PAPER This form vves designed using InFornis
Duke Energy Oconee Nuclear Station RPS/ES D> 3 Analysis July 1, 2003
Duke Energy . . .
Agenda
- Introductions
- Licensing interactions
- . RPS/ES D 3 analysis
- Manual Operator Response Times
- Leak Detection Capability
- 50.46 Single Failure Assumption
- Closing Remarks 2
Duke I ergy Licensing Interactions 00017 771 7 - -- ,
V:Duke appreciates the unique nature of this submittal
) Initial meeting with staff on March 7, 2002
) Working closely with lead reviewer
) Followed established guidance
) Analysis submitted on March 20, 2003
- o NRC response needed as input into design of RPS/ES digital upgrade
) Eliminates need for diverse LPI actuation feature 3
Duke L
Energy RPS/ES D 3 Analysts RPSIES D 3 Analysis
- Summary of Methodology
- Analysis Results
) Diverse Design Features Credited
) Operator Actions Credited
- Conclusions 4
uke Energy RPS/ES D3 Analysis Summary of Methodology
> Extensions of existing NRC-approved methodologies currently in UFSAR
> Codes: RETRAN-3D, VIPRE-01, RELAP5/MOD2-B&W, FATHOMS, SIMULATE, LOCADOSE
- SBLOCA analyzed by FANP using RELAP5/MOD2/B&W
- LBLOCA addressed by leak detection and low probability (otherwise need diverse actuation of Low Pressure Injection System) 5
Duke rneg F
RPS/ES D 3 Anaysias Summary of Methodoloqv (cont.)
Transients and Accidents Considered Control rod bank withdrawal at zero power Control rod bank withdrawal at full power Boron dilution at full power Loss of coolant flow Locked rotor Dropped control rod Turbine trip Steam generator tube rupture Control rod ejection Large steam line break Small steam line break Small break LOCA Large break LOCA Loss of main feedwater Loss of offsite power Main feedwater line break 6
Du Eke RPSIES D 3 Analysis Summary of Methodology (cont.)
Assumptions Typical conservative initial conditions
- i- No loss of offsite power No single failures Integrated Control System (ICS) in automatic Realistic core power distribution (SBLOCA only)
Realistic core flood tank initial conditions (SBLOCA only)
Realistic operator actions and times Credit for AMSAC (trip turbine and start EFW on loss of main feedwater)
Credit for existing Diverse Scram System (DSS) at 2450 psig RCS pressure Credit for Automatic Feedwater Isolation System (AFIS) on low SG pressure Pre-existing SG tube leakage at administrative limit 7
^ Duke tEEn ergy RIPS/ES D 3 Analysis Summary of Methodology (cont.)
Acceptance Criteria
- Offsite dose limits based on R. G. 1.183
> Large steam line break 25 rem TEDE (EAB & LPZ)
> Loss of flow 2.5 rem TEDE (EAB & LPZ)
- Reactor Building overpressure limit is 125 psi based on 98% of ultimate strength (design pressure is 59 psig) 8
^ Duke EdEn ergy RPS/ES D 3 Analysis Summary of Methodology (cont.)
Results Categories
- 1 - RPS and ESPS not actuated / no adverse impact
- 2 - Event terminated by DSS actuation / no adverse impact
- 3 - Event bounded by another event
- 4 - Analysis required and results show acceptance limits are met
- 5 - Acceptance limits not met / fail diversity and defense-in-depth 9
kDuke tEnergy RPS/ES I23 Analysis Analysis Results Category 1 - RPS and ESPS Not Actuated / No Adverse Impact
- Dropped control rod
- Steam generator tube rupture
- Small steam line break (for RCS pressure response and offsite doses)
) The UFSAR analysis does not credit automatic RPS or ESPS actuation 10
9 Dukerg RPSIES D 3 Analysis Analysis Results (cont.)
Category 2 - Event Terminated by DSS Actuation / No Adverse Impact
- Control rod bank withdrawal at zero power
- Loss of main feedwater
- Loss of offsite power
- Main feedwater line break
> The DSS mitigates the event when RCS pressure reaches 2450 psig 11
9DukeRPS/ES SBEnergy __gS D, Analysi's 3
nayi Analysis Results (cont.)
Category 3 - Event Bounded by Another Event / No Adverse Impact
- Boron dilution at full power (bounded by control rod bank withdrawal)
- Control rod ejection containment response and dose results (bounded by LOCA)
> Manual actuation of HPIS at 5 minutes credited
> Manual actuation of RBCS and RBS at 8 minutes credited
) Manual actuation of RBCS and RBS at 8 minutes credited 12
D~uke
.nergy RPIES D 3 Analysis Analysis Results (cont.)
Category 4 - Analysis Required and Acceptance Criteria Met
- Control rod bank withdrawal at full power
) No cladding failures, so offsite doses are not significant
) RCS and Reactor Building pressure limits not challenged
- Loss of coolant flow (four-pump coastdown) 26.0% cladding failure and 2.14% fuel melt Radiological doses bounded by two-pump coastdown RCS and Reactor Building pressure limits not challenged 13
Duke En ergyy RPS/ES D 3 Analysis Analysis Results (cont.)
Category 4 - Analysis Required and Acceptance Criteria Met (cont.)
- Loss of coolant flow (two-pump coastdown) 26.6% cladding failure and 2.46% fuel melt RCS and Reactor Building pressure limits not challenged Radiological doses
Duknergy RPS/ES D 3 Analysis Analysis Results (cont.)
Category 4 - Analysis Required and Acceptance Criteria Met (cont.)
- Large steam line break
> 34.0% cladding failure and 4.75% fuel melt
> RCS pressure limit is not challenged
> Peak containment pressure is 44 psig
> Radiological doses
luke w
rneg R1PS/E D 3 Analysis Analysis Results (cont.)
Category 4 - Analysis Required and Acceptance Criteria Met (cont.)
- Locked rotor
>- No cladding failures, so offsite doses are not significant
) RCS and Reactor Building pressure limits not challenged
- Small steam line break
) Peak containment pressure is 45 psig
- Manual actuation of RBCS and RBS credited at 8 minutes 16
^ Duke tEEn ergy RPSIES D 3 Analysis Analysis Results (cont.)
Category 4 - Analysis Required and Acceptance Criteria Met (cont.)
- Small-break LOCA
> Reactor manually tripped by the operator at 2 minutes
> Reactor coolant pumps manually tripped by the operator at 2 minutes
> HPI and LPI manually started by the operator at 5 minutes
> Peak cladding temperature is limited to around 1000F
> RCS pressure limit not challenged 17
^ Duke rEEnergy RRPS/ES D 3 Analysis Analysis Results (cont.)
Category 5 - Acceptance Limits Not Met
- Large-break LOCA
>- Crediting manual start of HPI and LPI at 5 minutes is not early enough to maintain a coolable geometry
>- LBLOCA does not meet the diversity and defense-in-depth requirements
> A diverse actuation of LPI is required if LOCA within the scope of the D 3 study
> LOCA addressed by leak detection and low probability - not required to meet diversity and defense-in-depth requirements.
18
luke wnergy RPS/ES D 3 Analysis Conclusions
- Diversity and defense-in-depth demonstrated for all events except large-break LOCA
- Existing diverse plant systems credited for automatic mitigation
> DSS
) AMSAC
) AFIS
> lCS 19
Duke I RPSIES D 3 Analysis
~nergy Conclusions (cont.)
%* New manual operator action times credited
) Manual reactor trip at 2 minutes (SBLOCA)
) Manual start of HPI and LPI at 5 minutes (SBLOCA, REA)
) Manual start of RBCS and RBS at 8 minutes (SBLOCA, REA)
- Acceptance criteria met (except for LBLOCA)
) Diverse actuation of LPI required for LBLOCA with failure of ESPS
) Leak detection and low probability justification to preclude LBLOCA 20
Duke
.ne~rgy OperatorResponse Times Process Used to Develop Times
- Scenario analysis to develop operator response times based on previously validated times and operator judgment
- Structured approach for transient mitigation prior to reactor trip (memory)
- e Immediate operator actions after reactor trip (memory)
- Symptoms check and parallel actions (manual action response times based on previous validations) 21
Puke Eergy Leak Detection Capability
- Oconee's capability and methods are similar to others in nuclear industry
) Sump Level Monitoring
) Radioactive Particulate Monitoring
) Radioactive Gaseous Monitoring
) Other means, e.g., RCS leakage calc, RCS makeup flow, LDST level monitoring 22
1f okr Use of LBB for RCS Piping M
> Previously approved in SER dated December 12,1985
- Oconee RCS has Inconel welds
I
'uke 50.46 Single Failure Energy Assumption
%* SWCMF is not a single failure based on NRC endorsed guidelines for licensing digital upgrades.
- NRC RIS 2002-22 endorsed EPRI TR-102348 Rev.1
) D 3 analysis is considered a beyond design basis concern
) Recognizes the likelihood of a common case software failure in a high quality digital system is significantly below that of a single active hardware failure 24
9 Efne~rgy r
Duke ClosingRemark.s .
- .:* Closing Remarks 25