Fire PRA Cable Selection (Task 3) - Revision history

User: /* NEI 00‑01 */

2021-11-12T13:58:31Z

NEI 00‑01

User: /* Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure (EPRI 3002009214 / NUREG/CR‑7150 Volume 3) */

2021-11-12T13:47:53Z

Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure (EPRI 3002009214 / NUREG/CR‑7150 Volume 3)

User: /* Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure (EPRI 3002009214 / NUREG/CR‑7150 Volume 3) */

2021-11-12T13:46:37Z

User: /* NEI 00‑01 */

2021-11-12T13:45:46Z

NEI 00‑01

User: /* NEI 00‑01 */

2021-11-12T13:44:37Z

NEI 00‑01

User: /* NEI 00‑01 */

2020-04-27T14:04:06Z

NEI 00‑01

User: /* Supplemental Guidance */

2020-04-27T13:59:59Z

Supplemental Guidance

User: /* Methodology for Modeling Plant Trip Probabilities in Nuclear Power Plant Fire Probabilistic Risk Assessment (EPRI 3002016053) */

2020-04-24T13:17:36Z

Methodology for Modeling Plant Trip Probabilities in Nuclear Power Plant Fire Probabilistic Risk Assessment (EPRI 3002016053)

User: /* Background */

2020-04-03T14:48:20Z

Background

User: /* Background */

2020-04-03T14:13:14Z

Background

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 ===[https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01]===
 NEI&nbsp;00&#8209;01 documents the cable selection and circuit analysis processes as well as the criteria for deterministic analyses and Fire PRAs.
-* Parts of [https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01 Revision&nbsp;2] are endorsed in NRC [https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=ML17340A875 RG&#8209;1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;3] February&nbsp;2018
+* Parts of [https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01 Revision&nbsp;2] are endorsed in NRC [https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=ML17340A875 RG&#8209;1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;3] February&nbsp;2018.
 * [https://www.nrc.gov/docs/ML1935/ML19351D273.html NEI 00-01 Revision 4] was issued in December 2019 to include the topics addressed in [https://www.epri.com/#/pages/product/000000003002009214/ EPRI 3002009214 / NUREG/CR-7150 Volume 3].  Parts of the NEI 00-01 revision, including the content from EPRI 3002009214 / NUREG/CR 7150 Volume 3, are endorsed in [https://www.nrc.gov/docs/ML2104/ML21048A441.pdf RG 1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;4] May 2021.

@@ Line 69: / Line 69: @@
 ====Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure ([https://www.epri.com/#/pages/product/000000003002009214/ EPRI&nbsp;3002009214 / NUREG/CR&#8209;7150 Volume&nbsp;3])====
-This report provides technical recommendations to resolve long-standing issues related to evaluation of multiple spurious operations and deterministic post-fire safe shutdown analyses. Note that the approaches and content from EPRI 3002009214 / NUREG/CR 7150 Volume 3 was incorporated into NEI 00-01 Revision 4 and endorsed by the NRC in RG 1.189 Revision 4.
+This report provides technical recommendations to resolve long-standing issues related to evaluation of multiple spurious operations and deterministic post-fire safe shutdown analyses. Note that the approaches and content from EPRI&nbsp;3002009214 / NUREG/CR&#8209;7150 Volume&nbsp;3 was incorporated into NEI&nbsp;00&#8209;01 Revision&nbsp;4 and endorsed by the NRC in RG&nbsp;1.189 Revision&nbsp;4.
 :'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''

@@ Line 69: / Line 69: @@
 ====Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure ([https://www.epri.com/#/pages/product/000000003002009214/ EPRI&nbsp;3002009214 / NUREG/CR&#8209;7150 Volume&nbsp;3])====
-This report provides technical recommendations to resolve long-standing issues related to evaluation of multiple spurious operations and deterministic post-fire safe shutdown analyses.
+This report provides technical recommendations to resolve long-standing issues related to evaluation of multiple spurious operations and deterministic post-fire safe shutdown analyses. Note that the approaches and content from EPRI 3002009214 / NUREG/CR 7150 Volume 3 was incorporated into NEI 00-01 Revision 4 and endorsed by the NRC in RG 1.189 Revision 4.
 :'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''

@@ Line 38: / Line 38: @@
 NEI&nbsp;00&#8209;01 documents the cable selection and circuit analysis processes as well as the criteria for deterministic analyses and Fire PRAs.
 * Parts of [https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01 Revision&nbsp;2] are endorsed in NRC [https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=ML17340A875 RG&#8209;1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;3] February&nbsp;2018
-* [https://www.nrc.gov/docs/ML1935/ML19351D273.html NEI 00-01 Revision 4] was issued in December 2019 to include the topics addressed in EPRI 3002009214 / NUREG/CR 7150 Volume 3.  Parts of the NEI 00-01 revision, including the content from EPRI 3002009214 / NUREG/CR 7150 Volume 3, are endorsed in [https://www.nrc.gov/docs/ML2104/ML21048A441.pdf RG 1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;4] May 2021.
+* [https://www.nrc.gov/docs/ML1935/ML19351D273.html NEI 00-01 Revision 4] was issued in December 2019 to include the topics addressed in [https://www.epri.com/#/pages/product/000000003002009214/ EPRI 3002009214 / NUREG/CR-7150 Volume 3].  Parts of the NEI 00-01 revision, including the content from EPRI 3002009214 / NUREG/CR 7150 Volume 3, are endorsed in [https://www.nrc.gov/docs/ML2104/ML21048A441.pdf RG 1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;4] May 2021.
 ===Fire-Induced Spurious Operations===

@@ Line 37: / Line 37: @@
 ===[https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01]===
 NEI&nbsp;00&#8209;01 documents the cable selection and circuit analysis processes as well as the criteria for deterministic analyses and Fire PRAs.
-* Parts of [https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01 Revision&nbsp;2] are endorsed in NRC [https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=ML17340A875 RG&#8209;1.189, ''Fire Protection for Nuclear Power Plants''] Revision&nbsp;3 February&nbsp;2018
+* Parts of [https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01 Revision&nbsp;2] are endorsed in NRC [https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=ML17340A875 RG&#8209;1.189, ''Fire Protection for Nuclear Power Plants'' Revision&nbsp;3] February&nbsp;2018
 ===Fire-Induced Spurious Operations===

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 ==Supplemental Guidance==
-Since the publication of NUREG/CR-6850, significant research on fire-induced spurious operations has occurred. This has resulted in the publication of three EPRI/NRC reports on this subject.
+===[https://www.nrc.gov/docs/ML0917/ML091770265.pdf NEI&nbsp;00&#8209;01]===
-===[https://www.epri.com/#/pages/product/000000000001026424/ Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Phenomena Identification and Ranking Table (PIRT) Exercise for Nuclear Power Plant Fire-Induced Electrical Circuit Failure (EPRI 1026424 / NUREG/CR-7150 Volume 1)]===
+===Fire-Induced Spurious Operations===
 This report documents a Phenomena Identification and Ranking Table (PIRT) exercise on fire-induced electrical circuit failures that may occur in nuclear power plants as a result of fire damage to cables. The results and conclusions of the PIRT panel are a primary input to the follow on PRA Expert Panel documented in Volume 2.
-'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''
+====Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Expert Elicitation Exercise for Nuclear Power Plant Fire-Induced Electrical Circuit Failure ([https://www.epri.com/#/pages/product/000000003002001989/ EPRI&nbsp;3002001989 / NUREG/CR&#8209;7150 Volume&nbsp;2])====
 This report documents the results of the PRA panel's expert elicitation that is used to develop the conditional probabilities of hot-short induced spurious operation & duration of various control circuit configurations.
-'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''
+:'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''
-* A new failure mode, the Ground Fault Equivalent Hot Short (GFEHS) has been identified. A GFEHS occurs when fire damage results in conductors of the same or different cable developing a relatively low impedance fault with a ground plane. For the GFEHS to cause a hot short induced spurious operation, both a source and target conductor must short to the same ground plane and have a compatible power supply. Source conductors are those which can supply energy (voltage, current). Target conductors are associated with end devices such as a conductor connected to a solenoid or a conductor connected to a contactor of a motor starter.
+:* A new failure mode, the Ground Fault Equivalent Hot Short (GFEHS) has been identified. A GFEHS occurs when fire damage results in conductors of the same or different cable developing a relatively low impedance fault with a ground plane. For the GFEHS to cause a hot short induced spurious operation, both a source and target conductor must short to the same ground plane and have a compatible power supply. Source conductors are those which can supply energy (voltage, current). Target conductors are associated with end devices such as a conductor connected to a solenoid or a conductor connected to a contactor of a motor starter.
-** Spurious operation caused by shorting conductors through a surrogate ground path in ungrounded circuits as a result of fire induced damage, is a failure mode which occurred during the [https://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr7100// DESIREE-Fire testing] and is referred to as “Ground Fault Equivalent Hot Short.” The probability of this failure mechanism with respect to cable-to-cable hot shorts is such that it warrants consideration for including in future testing programs and, subsequently, in analyzing post-fire safe-shutdown conditions.
+:** Spurious operation caused by shorting conductors through a surrogate ground path in ungrounded circuits as a result of fire induced damage, is a failure mode which occurred during the [https://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr7100// DESIREE-Fire testing] and is referred to as “Ground Fault Equivalent Hot Short.” The probability of this failure mechanism with respect to cable-to-cable hot shorts is such that it warrants consideration for including in future testing programs and, subsequently, in analyzing post-fire safe-shutdown conditions.
-*Conditional probabilities and spurious operation duration are covered in Task 10.
+:*Conditional probabilities and spurious operation duration are covered in Task 10.
-(The memos and letters dated June 14, 2013, December 16, 2013, February 12, 2014, and April 23, 2014 referenced interim guidance until the issuance of NUREG/CR-7150, Volume 2, in May 2014.  '''NUREG/CR-7150, Vol. 2 should be referred to as the official guidance.  The purpose of the memos and letters is to trace NRC acceptance of the guidance.''')
+:'''NRC Correspondence'''
-===[https://www.epri.com/#/pages/product/000000003002009214/ Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure (EPRI 3002009214 / NUREG/CR-7150 Volume 3)]===
+====Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues on Nuclear Power Plant Fire-Induced Circuit Failure ([https://www.epri.com/#/pages/product/000000003002009214/ EPRI&nbsp;3002009214 / NUREG/CR&#8209;7150 Volume&nbsp;3])====
 This report provides technical recommendations to resolve long-standing issues related to evaluation of multiple spurious operations and deterministic post-fire safe shutdown analyses.
-'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''
+:'''Impact on EPRI 1011989 NUREG/CR-6850 Guidance'''
-*Clarified circuit failure modes and terminology including: proper polarity, latching versus non-latching, high impact components, failure mode classification and GFEHS
+:*Clarified circuit failure modes and terminology including: proper polarity, latching versus non-latching, high impact components, failure mode classification and GFEHS
-*Revised several PIRT panel positions following the conclusions of the PRA Expert Panel
+:*Revised several PIRT panel positions following the conclusions of the PRA Expert Panel
-**Consideration of insulation type for the aggressor cable conductor is eliminated. This was eliminated due to the impracticality of tracking the conductor insulation for aggressor cables. As a result, the reported classifications are a function of the conductor insulation of the target conductor.
+:**Consideration of insulation type for the aggressor cable conductor is eliminated. This was eliminated due to the impracticality of tracking the conductor insulation for aggressor cables. As a result, the reported classifications are a function of the conductor insulation of the target conductor.
-**Classification of inter-cable hot shorts for thermoset insulated conductors from "implausible" to "plausible" based on the PRA expert panel probabilities that did not support a classification of "implausible"
+:**Classification of inter-cable hot shorts for thermoset insulated conductors from "implausible" to "plausible" based on the PRA expert panel probabilities that did not support a classification of "implausible"
-**Grouped single break ungrounded AC (from common CPT or distributed) with DC due to similarities in circuit failure type classification.
+:**Grouped single break ungrounded AC (from common CPT or distributed) with DC due to similarities in circuit failure type classification.
-**Classified inter-cable hot shorts for double break design with TP insulated conductors as "implausible" for latching and "incredible" for non-latching circuits. This classification was deferred until the PRA Expert Panel completed their estimation.
+:**Classified inter-cable hot shorts for double break design with TP insulated conductors as "implausible" for latching and "incredible" for non-latching circuits. This classification was deferred until the PRA Expert Panel completed their estimation.
-*Developed technical design considerations for shorting switch applications
+:*Developed technical design considerations for shorting switch applications
-*Disposition of secondary fires due to a fire-induced open circuited current transformer
+:*Disposition of secondary fires due to a fire-induced open circuited current transformer
-**Testing is documented in [https://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr7228// NUREG/CR-7228, ''Open Secondary Testing of Window-Type Current Transformers'']
+:**Testing is documented in [https://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr7228// NUREG/CR-7228, ''Open Secondary Testing of Window-Type Current Transformers'']
-===[https://www.epri.com/#/pages/product/3002016053/ Methodology for Modeling Plant Trip Probabilities in Nuclear Power Plant Fire Probabilistic Risk Assessment (EPRI 3002016053)]===
+===Methodology for Modeling Plant Trip Probabilities in Nuclear Power Plant Fire Probabilistic Risk Assessment ([https://www.epri.com/#/pages/product/3002016053/ EPRI&nbsp;3002016053])===
 Typically, a Fire PRA assumes a reactor trip for fire scenarios unless it can be demonstrated that no Fire PRA components are impacted and the reactor will not trip. As a result, very few Fire PRA scenarios are screened from quantification. The operating experience in the United States was reviewed and showed that only one in six events results in a plant trip, and the events are strongly correlated with a few ignition source bins mainly related to electrical distribution and the turbine generator. This report documents a methodology and screening process that can be applied to fire scenarios for ignition source bins where a plant trip is unlikely to occur. For qualifying scenarios, a 0.1 conditional trip probability can be applied.

← Older revision		Revision as of 13:17, 24 April 2020
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	===[https://www.epri.com/#/pages/product/3002016053/ Methodology for Modeling Plant Trip Probabilities in Nuclear Power Plant Fire Probabilistic Risk Assessment (EPRI 3002016053)]===		===[https://www.epri.com/#/pages/product/3002016053/ Methodology for Modeling Plant Trip Probabilities in Nuclear Power Plant Fire Probabilistic Risk Assessment (EPRI 3002016053)]===
−	Typically, a ~~FPRA~~ assumes a reactor trip for fire scenarios unless it can be demonstrated that no ~~FPRA~~ components are impacted and the reactor will not trip. As a result, very few ~~FPRA~~ scenarios are screened from quantification. The operating experience in the United States was reviewed and showed that only one in six events results in a plant trip, and the events are strongly correlated with a few ignition source bins mainly related to electrical distribution and the turbine generator. This report documents a methodology and screening process that can be applied to fire scenarios for ignition source bins where a plant trip is unlikely to occur. For qualifying scenarios, a 0.1 conditional trip probability can be applied.	+	Typically, a Fire PRA assumes a reactor trip for fire scenarios unless it can be demonstrated that no Fire PRA components are impacted and the reactor will not trip. As a result, very few Fire PRA scenarios are screened from quantification. The operating experience in the United States was reviewed and showed that only one in six events results in a plant trip, and the events are strongly correlated with a few ignition source bins mainly related to electrical distribution and the turbine generator. This report documents a methodology and screening process that can be applied to fire scenarios for ignition source bins where a plant trip is unlikely to occur. For qualifying scenarios, a 0.1 conditional trip probability can be applied.

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 === Background ===
-This task provides instructions and technical considerations associated with identifying cables supporting those components selected in Task 2. In previous Fire PRA methods (such as [https://www.epri.com/#/pages/product/TR-100370/ EPRI FIVE] and the Fire PRA Implementation Guide) this task was relegated to the SSD analysis and its associated databases. This document offers a more structured set of rules for selection of cables.
+This task provides instructions and technical considerations associated with identifying cables supporting those components selected in Task 2. In previous Fire PRA methods (such as [https://www.epri.com/#/pages/product/TR-100370/ EPRI FIVE] and EPRI's Fire PRA Implementation Guide [TR-105928, no longer available on epri.com]) this task was relegated to the SSD analysis and its associated databases. This document offers a more structured set of rules for selection of cables.
 === Purpose ===