ML14219A476

Operating Experience on Initial Test Program

ML14219A476
Person / Time
Site:	Summer, Vogtle
Issue date:	08/07/2014
From:	Laura R NRC/NRO/DCIP/CQAB
To:
Laura R
References
Download: ML14219A476 (21)

Text

Ope ating Experience Operating E pe ience 8/7/2014 1

OpE shows Initial Testing Important to . . .

Verify V if plant l built b il as designed, d i d validate lid design d i Identify inadequacies, adverse system interactions.

OpE for Initial Testing is considered because . . .

Regulatory R l commitments i - DCD Experiences from Part 50 Plant Startup Industry d Operating Lessons - Plant l Events 8/7/2014 2

Design Control Document Section 14.2.5, Rev 19 Utilization Utili ti off Reactor R t Operating O ti & Startup St t Experience E i in i

Development of Test Program Past PWR Operating Experience & Testing Experience Used to Develop Initial Test Program Other Sources of OpE Used in AP1000 ITP Question: How is this being done for Vogtle?

Summer?

8/7/2014 3

Safety Culture in Pre-operational Phases of Nuclear Power P Plant Pl Projects P j dated d d 2012 Source: IAEA Safety Report Series - # 74

(

(Publication 1555))

Safety culture includes questioning attitude, organizational i i l learning, l i proactive i approach h

Operating Experience is important component of O

Organizational i ti lL Learning i

Proper safety perspective for Initial Testing - one that proves SSCs are functional 8/7/2014 4

INTERNATIONAL p

2011 European Summaryy Report p g on Construction and Commissioning International reporting System (IRS) - Web Search 18 hits DOMESTIC NRC Circulars & Information Notices - 16 hits NRC Licensee Event Reports LERs - 155 hits NUREG 1055 Improving Quality in Design / Construction of NPPs , 1984 NUREG NUREG-1275 V l Volume 1 - IRS Summary S Report R

NUREG-0969 , Zimmer Project, 1983 INDUSTRY INPO Documents and References - SOERs, SERs WEB SEARCHES Industry, Domestic, International 8/7/2014 5

p Preoperational Testingg Lessons Learned Adequate Planning for Preoperational Test execution Plan Transition from Construction to Testing System & Organizational Turnover Adequate Test Procedure Quality assures Fidelity between Preoperational/Startup Tests and Designg Basis Documents - DCDs FSAR 8/7/2014 6

Preoperational Testing Lessons Learned Functional F ti l testing t ti iis fi finall barrier b i tto reveall construction deficiencies resulting in SSCs unable bl to t perform f design d i ffunctionti 8/7/2014 7

European Commission Joint Research Center Summary S Report R t on Nuclear N l Power P Plants Pl t Construction, C t ti Commissioning and Manufacturing Events, 2011 Analysis to identify events from construction and commissioning of NPPs Three sources of information NRC Licensee Event Reports (LERs)- 309 LERs applicable Incident Reporting System S stem (IRS)-247 (IRS) 24 reports applicable Working Group on Regulation for New Reactors (WGRNR)

- 26 WGRNR events were applicable to study 8/7/2014 8

European Commission Joint Research Center Summary S Report R t Major M j Conclusions C l i Items most affected by construction or commissioning deviations are I&C (19%), electrical components (17%),

welds (14%), valves (10%) and pipes (9%).

Average detection time of the initial defect is about 8 years after the start of commercial operation.

Common cause failures can be high for some materials:

more than 50 % for civil work and fire protection, 45 % for electrical components (the average is 34 %)

8/7/2014 9

International Lessons Learned . . .

European E Commission C i i Joint J i t Research R h Center C t Summary Report Major Conclusions More than 75 % of the events are found fortuitously, and the rate of detection is particularly high for civil work, electrical components components, I&C, I&C pipes and valves.

valves Some items such as civil work (structure, anchorages, supports)) andd electrical l i l components exhibit hibi allll three:

h a long detection time, a high rate of common cause failure g rate of fortuitous detection.

and a high 8/7/2014 10

International Lessons Learned . . .

European E Commission C i i Joint J i t Research R h Center C t Summary Report Major Conclusions The conclusions emphasize the need to minimize the number of deficiencies during construction construction, manufacturing and commissioning of a new reactor, as they can be major latent failures for a long time and can have safety consequences after f reactors start to operate.

8/7/2014 11

q Inadequate p Pre-Operational g Results in Plant Testing Operation with SSCs not functioning per design BWR: HPCI/RCIC flow not calibrated correctly since startup LER 353/2-2007-03 PWR: Protection Instrument Calibration Graphs inadequate since startup LER 305/2009-06 8/7/2014 12

q Inadequate p Pre-Operational g Results in Plant Testing Operation with SSCs not functioning per design PWR: Inadequate PMT of frequency relay setting results in dual unit loss of offsite power LER 413/2012-01 BWR: wiring errors in EDG control logic circuit results in inability to locally operate EDG from the Safe Shutdown Panel LER 324/2008-06 8/7/2014 13

OpE Shows Effective Preoperational Testing Important to . . .

Identify unrecognized Intersystem Dependencies Identify Single Point Vulnerabilities Avoid Unwanted Consequences Plant events - domestic & foreign g (next

( slides))

Scrams with complications Multiple train failures Increases in Core Damage Frequency 8/7/2014 14

Reactor Transients, LOOPS and Scrams with Complications Recent nuclear plants events involve examples where multiple trains of equipment were affected by single event or common cause failure Other significant events involve the common cause failure of non-non safety related electrical equipment The h events provide d insights h on potentiall failure f l modes d that h could ld be avoided with proper attention to design and testing during the construction and initial testing phases 8/7/2014 15

Reactor Transients, LOOPS and Scrams with Complications BWR Dual Unit Scram & LOOP 2013 Deficient D fi i electrical l i l connections i i the in h switchyard i h d grounding di system due to poor workmanship existing since original construction LER 373/2013-02 BWR Scram with Complications 2013 Proper P postt modification difi ti ttesting ti should h ld id identify tif single i l point i t vulnerability in non-safety systems that impacts plant safety LER 293/2013-01 8/7/2014 16

Reactor Transients, LOOPS and Scrams with Complications Foreign g BWR Scram,, LOOP & Complicated p LOOP 2006 Preoperational testing should identify EDS design vulnerabilities such as proper phase connections of protection relays.

y IN 2006-18.

PWR Scram, 345kV Open Phase & Fault 2012 Preoperational testing should verify design of the under-voltage protection intended to identify degraded grid conditions LER 454/2012-01 8/7/2014 17

Four Recent Significant Events Highlight that. . .

Plant Pl t events t are causedd by b single i l point i t vulnerabilities & common mode failures Events result from design errors, inadequate designg modifications and reviews,, and inadequate work control or work practices Events caused by unrecognized workmanship or installation errors from original construction.

8/7/2014 18

Four Recent Significant Events highlight that. . .

Functional testing is the final barrier to reveal construction deficiencies Robust and comprehensive p test p program g can identify design and installation deficiencies Proper consideration of Operational Experience helps assure Initial Testing is effective 8/7/2014 19

Q Questions?

ti  ?

8/7/2014 20

NRC Inspection Procedures for New Reactor Plant Initial Test Programs

• IP 70367, Part 52, Inspection of Preoperational Test Program

• IP 70702, 0 0 , Inspection spect o o of Preoperational eope at o a Test est Program Performance

• NRC AP1000 Preoperational Test Program Inspection Planning Tool

• IP 72401, Part 52, Inspection of the Startup Test Program

• IP 72304, 72304 St Startup t T Testing ti ffor th the AP1000, AP1000 TTestt Procedure Review, Test Witnessing and Test Results Evaluation (under final review for issuance)