scram trends - aventri

© Copyright 2018 Institute of Nuclear Power Operations

Scram Trends2018 RAPID meeting

May 2018Carl Lane

Sr. Evaluator

Equipment Reliability

INPO

© Copyright 2018 Institute of Nuclear Power Operations 2

15

65 6770 71

7477

62 62

69

5964

52

38 38

46

5651

56 5762

40

50

57

41

49

40

32 32

2 28

5 4 5

14

4 48 7

2 1 0

17

9 11 1013

10

8

8 8 10 8 105 6

0

10

20

30

40

50

60

70

80

90

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 last365

daysending5-18-18

2018YTD

ending5-18-18

General Scram Causes by Number

2018 Total Scrams Equipment External Direct Human Action

Limited Distribution - Data Management and Industry Trends, INPO/WANO AC


2018 Scram OverviewThe scram reduction initiative experienced continued success in 2017 with

unplanned scrams reducing to 38, over a 50 percent improvement since 2010

(77 scrams). Record low numbers of scrams occurred in three of the past four

years. As of May 8, 2018, 15 scrams have occurred as compared to 15 at the

same time in 2017.

• Scrams causes

– Equipment related scrams accounted for 5 of 15 scrams.

– Design related issues contributed to 4 of 15 scrams

– Maintenance fundamentals contributed to 3 of 15 scrams

– Manufacturing issues contributed to 1 of 15 scrams

– Determination of cause is pending on 2 of 15 scrams.

• PWRs accounted for 9 of 15 scrams, BWR accounted for 6 of 15 scrams.

• Auto scrams accounted for 9 of 15 scrams.

• Turbine/Generator scrams account for 8 of 15 scrams

3


2018 Scram Performance

• Entergy, TVA and Duke units accounted for

67% (10 of 15 scrams).

– Entergy accounts for 4 scrams

– TVA and Duke each have experienced 3 scrams


Maint/ WM, 8, 18%

Design, 11, 25%

PM Program Issues, 6, 14%

Manufacturing Issues, 5, 11%

2017 Scrams (data pending)

Data Management and Industry Trends, INPO

Maintenance(Equipment Failure)

Design (Equipment Failure)

Equipment

Reliability (Equipment Failure)

Non-Equipment Related


Scram Review Visits

• Vulnerabilities are not recognized – lack of worker awareness and sensitivity to scram sensitive equipment and conditions

• A consequence-biased approach is not applied to risk determination and decision making

• Weaknesses in single point vulnerability mitigation and eliminations strategies

• Untimely resolution of known degraded conditions

• Aggregate scram reviews not performed to determine gaps to IER L2-11-2 recommendations


Scram Review Visits

• System health reports for scram significant systems and components do not adequately identify scram vulnerabilities such as a lack of mitigating strategies and obsolescence.

• A parts-quality initiative includes controls for pre-receipt testing to ensure parts for scram vulnerable components (beneficial practice)

• Circuit card testing and refurbishment facility (beneficial practice)


Common Performance Gaps• Elevate the awareness and visibility of SPV

components to reinforce the potential scram consequences and unrecoverable actions.

• Establish or continue to reinforce a bias for elimination of SPVs


Elevate the awareness and visibility of SPV components to reinforce the potential scram consequences and unrecoverable actions.

• Align station personnel to a common understanding -including definition, roles, and responsibilities for affected work groups - of SPVs and conditional SPVs. Communications should reinforce an elimination bias for SPVs.

• Evaluate SPVs to the subcomponent level, and include known passive SPVs that have an active failure mode in the elimination/mitigation population.

• Communicate to operations, maintenance and vendor personnel the importance of a formal approach to actions and requirements when performing field activities on SPV components, especially activities with a perceived low risk.

• Evaluate implementation of field demarcation/protection for trip-sensitive equipment.


Establish or continue to reinforce a bias for elimination of SPVs

• Establish a bias for SPV elimination; encourage innovative solutions using cross-functional insights.

• Consider "Additional Recommendations" listed in IER L2-ll-2 and General Electric boiling water reactor secondary plant OE for opportunities to harden scram-sensitive systems.

• Evaluate opportunities to eliminate SPVs on key systems.

• Review available EPRI SPV SharePoint data vulnerabilities and mitigation strategies.

• Ensure unique equipment identifiers are created for newly identified SPV subcomponents.


2009

2010

2011

2012 2013

2014

2015

2016

2017

0

2

4

6

8

10

12

14

Vendor Parts Quality Scrams2017 Data Pending

Data Management and Industry Trends, INPO


Vendor Quality –

OEM, 19, 83%

Vendor Quality - Alt Source, 1,

4%

Equip Refurb, 1,

4%

Storage, Shipping, or Handling, 0, 0%

Procurement Specs, 0, 0%

Unspecified, 2, 9%

Vendor Parts Quality Related Scramsby Cause (2015-2016)

Restricted Distribution - Data Management and Industry Trends, INPO/WANO AC


Over half of 2015-2016 scrams occurred within the first five years of service-life


Circuit cards are the major contributor to parts quality related scrams.

Many manufacturing-related (parts quality) scrams (~30%) were single point

vulnerabilities (SPVs).


Vendor Quality Data Availability

• Events of Consequence – Yes

Low availability of Data

• Installation discovery failures

• Bench Test failures

• Burn in failures

• Post Maintenance Testing


Your part in the evaluation• Get ENGAGED in the causal analysis

• CHALLENGE the conclusions


Additional Scram information may be obtained from INPO Member website.

Scram Information Page

Carl Lane - Equipment Reliability

(770) 644-8463 [email protected]

https://web.inpo.org/Pages/Scram-Information.aspx

scram trends - aventri

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