A study on the effect of flaw detection probability assumptions on risk reduction achieved by non-destructive inspection

Otso Cronvall; Kaisa Simola; Ilkka Männistö; J. Gunnars; L. Alverlind; P. Dillström; L. Gandossi

doi:10.1016/j.ress.2012.03.012

A study on the effect of flaw detection probability assumptions on risk reduction achieved by non-destructive inspection

Otso Cronvall (Corresponding Author), Kaisa Simola, Ilkka Männistö, J. Gunnars, L. Alverlind, P. Dillström, L. Gandossi

Research output: Contribution to journal › Article › Scientific › peer-review

11 Citations (Scopus)

Abstract

Leakages and ruptures of piping components lead to reduction or loss of the pressure retaining capability of the system, and thus contribute to the overall risk associated with nuclear power plants. In-service inspection (ISI) aims at verifying that defects are not present in components of the pressure boundary or, if defects are present, ensuring that these are detected before they affect the safe operation of the plant. Reliability estimates of piping are needed e.g., in probabilistic safety assessment (PSA) studies, risk-informed ISI (RI-ISI) applications, and other structural reliability assessments. Probabilistic fracture mechanics models can account for ISI reliability, but a quantitative estimate for the latter is needed. This is normally expressed in terms of probability of detection (POD) curves, which correlate the probability of detecting a flaw with flaw size. A detailed POD curve is often difficult (or practically impossible) to obtain. If sufficient risk reduction can be shown by using simplified (but reasonably conservative) POD estimates, more complex PODs are not needed. This paper summarises the results of a study on the effect of piping inspection reliability assumptions on failure probability using structural reliability models. The main interest was to investigate whether it is justifiable to use a simplified POD curve. Further, the study compared various structural reliability calculation approaches for a set of analysis cases. The results indicate that the use of a simplified POD could be justifiable in RI-ISI applications.

Original language	English
Pages (from-to)	90-96
Number of pages	7
Journal	Reliability Engineering and System Safety
Volume	105
DOIs	https://doi.org/10.1016/j.ress.2012.03.012
Publication status	Published - 2012
MoE publication type	A1 Journal article-refereed
Event	European Safety and Reliability Conference, ESREL 2010 - Rhodes, Greece Duration: 5 Sep 2010 → 9 Sep 2010

Keywords

Inspection reliability
probabilistic fracture mechanics (PFM)
probability of detection curves (POD)
risk-informed in-service inspection

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title = "A study on the effect of flaw detection probability assumptions on risk reduction achieved by non-destructive inspection",

abstract = "Leakages and ruptures of piping components lead to reduction or loss of the pressure retaining capability of the system, and thus contribute to the overall risk associated with nuclear power plants. In-service inspection (ISI) aims at verifying that defects are not present in components of the pressure boundary or, if defects are present, ensuring that these are detected before they affect the safe operation of the plant. Reliability estimates of piping are needed e.g., in probabilistic safety assessment (PSA) studies, risk-informed ISI (RI-ISI) applications, and other structural reliability assessments. Probabilistic fracture mechanics models can account for ISI reliability, but a quantitative estimate for the latter is needed. This is normally expressed in terms of probability of detection (POD) curves, which correlate the probability of detecting a flaw with flaw size. A detailed POD curve is often difficult (or practically impossible) to obtain. If sufficient risk reduction can be shown by using simplified (but reasonably conservative) POD estimates, more complex PODs are not needed. This paper summarises the results of a study on the effect of piping inspection reliability assumptions on failure probability using structural reliability models. The main interest was to investigate whether it is justifiable to use a simplified POD curve. Further, the study compared various structural reliability calculation approaches for a set of analysis cases. The results indicate that the use of a simplified POD could be justifiable in RI-ISI applications.",

keywords = "Inspection reliability, probabilistic fracture mechanics (PFM), probability of detection curves (POD), risk-informed in-service inspection",

author = "Otso Cronvall and Kaisa Simola and Ilkka M{\"a}nnist{\"o} and J. Gunnars and L. Alverlind and P. Dillstr{\"o}m and L. Gandossi",

year = "2012",

doi = "10.1016/j.ress.2012.03.012",

language = "English",

volume = "105",

pages = "90--96",

journal = "Reliability Engineering and System Safety",

issn = "0951-8320",

publisher = "Elsevier",

note = "European Safety and Reliability Conference, ESREL 2010, ESREL 2010 ; Conference date: 05-09-2010 Through 09-09-2010",

}

A study on the effect of flaw detection probability assumptions on risk reduction achieved by non-destructive inspection. / Cronvall, Otso (Corresponding Author); Simola, Kaisa; Männistö, Ilkka; Gunnars, J.; Alverlind, L.; Dillström, P.; Gandossi, L.

In: Reliability Engineering and System Safety, Vol. 105, 2012, p. 90-96.

Research output: Contribution to journal › Article › Scientific › peer-review

TY - JOUR

T1 - A study on the effect of flaw detection probability assumptions on risk reduction achieved by non-destructive inspection

AU - Cronvall, Otso

AU - Simola, Kaisa

AU - Männistö, Ilkka

AU - Gunnars, J.

AU - Alverlind, L.

AU - Dillström, P.

AU - Gandossi, L.

PY - 2012

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AB - Leakages and ruptures of piping components lead to reduction or loss of the pressure retaining capability of the system, and thus contribute to the overall risk associated with nuclear power plants. In-service inspection (ISI) aims at verifying that defects are not present in components of the pressure boundary or, if defects are present, ensuring that these are detected before they affect the safe operation of the plant. Reliability estimates of piping are needed e.g., in probabilistic safety assessment (PSA) studies, risk-informed ISI (RI-ISI) applications, and other structural reliability assessments. Probabilistic fracture mechanics models can account for ISI reliability, but a quantitative estimate for the latter is needed. This is normally expressed in terms of probability of detection (POD) curves, which correlate the probability of detecting a flaw with flaw size. A detailed POD curve is often difficult (or practically impossible) to obtain. If sufficient risk reduction can be shown by using simplified (but reasonably conservative) POD estimates, more complex PODs are not needed. This paper summarises the results of a study on the effect of piping inspection reliability assumptions on failure probability using structural reliability models. The main interest was to investigate whether it is justifiable to use a simplified POD curve. Further, the study compared various structural reliability calculation approaches for a set of analysis cases. The results indicate that the use of a simplified POD could be justifiable in RI-ISI applications.

KW - Inspection reliability

KW - probabilistic fracture mechanics (PFM)

KW - probability of detection curves (POD)

KW - risk-informed in-service inspection

U2 - 10.1016/j.ress.2012.03.012

DO - 10.1016/j.ress.2012.03.012

M3 - Article

VL - 105

SP - 90

EP - 96

JO - Reliability Engineering and System Safety

JF - Reliability Engineering and System Safety

SN - 0951-8320

T2 - European Safety and Reliability Conference, ESREL 2010

Y2 - 5 September 2010 through 9 September 2010

ER -