Background - Revision history

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2025-01-24T18:23:31Z

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Admin: /* Historical Background */

2025-01-17T21:39:05Z

Historical Background

← Older revision		Revision as of 21:39, 17 January 2025
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	<br>		<br>
	A PRA model is required as part of the risk-informed licensing basis for new water reactors under [https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/index.html Part 52 of 10 CFR] [[References\|[2]]] (NRC). For advanced reactor deployments, [https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-0034.html 10CFR50 section 34(f)(1)(i)] states that the license applicant is required to “Perform a plant/site specific probabilistic risk assessment, the aim of which is to seek such improvements in the reliability of core and containment heat removal systems that are significant and practical and do not impact excessively on the plant.” To address the large gap in the designs of current water reactors and advanced reactors, a standard that specifies requirements for developing a PRA for non-LWR (not water cooled) advanced reactors, [https://www.asme.org/codes-standards/find-codes-standards/probabilistic-risk-assessment-standard-for-advanced-non-light-water-reactor-nuclear-power-plants/2021/pdf ASME/ANS RA-S-1.4-2021], has been developed. Since licensing and operation of these advanced reactors represent a first-of-a-kind (FOAK) application, the US nuclear industry developed guidance [https://www.nrc.gov/docs/ML1924/ML19241A472.pdf (NEI 18-04)] [[References\|[8]]] for a modern, technology-inclusive, risk-informed, and performance-based (TI-RI-PB) process.		A PRA model is required as part of the risk-informed licensing basis for new water reactors under [https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/index.html Part 52 of 10 CFR] [[References\|[2]]] (NRC). For advanced reactor deployments, [https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-0034.html 10CFR50 section 34(f)(1)(i)] states that the license applicant is required to “Perform a plant/site specific probabilistic risk assessment, the aim of which is to seek such improvements in the reliability of core and containment heat removal systems that are significant and practical and do not impact excessively on the plant.” To address the large gap in the designs of current water reactors and advanced reactors, a standard that specifies requirements for developing a PRA for non-LWR (not water cooled) advanced reactors, [https://www.asme.org/codes-standards/find-codes-standards/probabilistic-risk-assessment-standard-for-advanced-non-light-water-reactor-nuclear-power-plants/2021/pdf ASME/ANS RA-S-1.4-2021], has been developed. Since licensing and operation of these advanced reactors represent a first-of-a-kind (FOAK) application, the US nuclear industry developed guidance [https://www.nrc.gov/docs/ML1924/ML19241A472.pdf (NEI 18-04)] [[References\|[8]]] for a modern, technology-inclusive, risk-informed, and performance-based (TI-RI-PB) process.

	<br>		<br>
	Ongoing industry collaboration is intended to support the need for additional and expanded guidance.		Ongoing industry collaboration is intended to support the need for additional and expanded guidance.

Admin: /* Historical Background */

2025-01-17T21:38:38Z

Historical Background

← Older revision		Revision as of 21:38, 17 January 2025
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	*Power ranges from tens of megawatts to thousands of megawatts.		*Power ranges from tens of megawatts to thousands of megawatts.
	*A variety of core types including solid fuels with liquid or gaseous coolants, balls or blades, liquid fuels or molten fuels, and multi module cores.		*A variety of core types including solid fuels with liquid or gaseous coolants, balls or blades, liquid fuels or molten fuels, and multi module cores.
	*State-of-the-art passive safety designs and digital I&C, which is not included in most traditional ~~LWRs~~.		*State-of-the-art passive safety designs and digital I&C, which is not included in most traditional water reactors.
	*Different avenues of radiation release are considered as a result of variation in reactor design.		*Different avenues of radiation release are considered as a result of variation in reactor design.
	*PRA for existing reactors includes Levels 1 to 3 for quantification of initiating events and all hazards, while for advanced reactors the quantification capability may vary from plant to plant.		*PRA for existing reactors includes Levels 1 to 3 for quantification of initiating events and all hazards, while for advanced reactors the quantification capability may vary from plant to plant.
	<br>		<br>
	A PRA model is required as part of the risk-informed licensing basis for new ~~light~~ water reactors ~~(LWRs)~~ under [https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/index.html Part 52 of 10 CFR] [[References\|[2]]] (NRC). For advanced reactor deployments, [https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-0034.html 10CFR50 section 34(f)(1)(i)] states that the license applicant is required to “Perform a plant/site specific probabilistic risk assessment, the aim of which is to seek such improvements in the reliability of core and containment heat removal systems that are significant and practical and do not impact excessively on the plant.” To address the large gap in the designs of current ~~LWRs~~ and advanced reactors, a standard that specifies requirements for developing a PRA for non-LWR advanced reactors, [https://www.asme.org/codes-standards/find-codes-standards/probabilistic-risk-assessment-standard-for-advanced-non-light-water-reactor-nuclear-power-plants/2021/pdf ASME/ANS RA-S-1.4-2021], has been developed. Since licensing and operation of these advanced reactors represent a first-of-a-kind (FOAK) application, the US nuclear industry developed guidance [https://www.nrc.gov/docs/ML1924/ML19241A472.pdf (NEI 18-04)] [[References\|[8]]] for a modern, technology-inclusive, risk-informed, and performance-based (TI-RI-PB) process.		A PRA model is required as part of the risk-informed licensing basis for new water reactors under [https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/index.html Part 52 of 10 CFR] [[References\|[2]]] (NRC). For advanced reactor deployments, [https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-0034.html 10CFR50 section 34(f)(1)(i)] states that the license applicant is required to “Perform a plant/site specific probabilistic risk assessment, the aim of which is to seek such improvements in the reliability of core and containment heat removal systems that are significant and practical and do not impact excessively on the plant.” To address the large gap in the designs of current water reactors and advanced reactors, a standard that specifies requirements for developing a PRA for non-LWR (not water cooled) advanced reactors, [https://www.asme.org/codes-standards/find-codes-standards/probabilistic-risk-assessment-standard-for-advanced-non-light-water-reactor-nuclear-power-plants/2021/pdf ASME/ANS RA-S-1.4-2021], has been developed. Since licensing and operation of these advanced reactors represent a first-of-a-kind (FOAK) application, the US nuclear industry developed guidance [https://www.nrc.gov/docs/ML1924/ML19241A472.pdf (NEI 18-04)] [[References\|[8]]] for a modern, technology-inclusive, risk-informed, and performance-based (TI-RI-PB) process.
	<br>		<br>
	Ongoing industry collaboration is intended to support the need for additional and expanded guidance.		Ongoing industry collaboration is intended to support the need for additional and expanded guidance.

Admin: /* Historical Background */

2025-01-17T21:36:10Z

Historical Background

← Older revision		Revision as of 21:36, 17 January 2025
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	==Historical Background==		==Historical Background==
	In the current fleet of US ~~LWRs~~, a measurable improvement of safety can be seen in the figure below which displays increasing plant capacity factors as a measure of operational performance with a simultaneous decrease in average estimated plant core damage frequency. PRA applications have made a significant contribution to both plant safety and operational flexibility and performance.		In the current fleet of US water reactors, a measurable improvement of safety can be seen in the figure below which displays increasing plant capacity factors as a measure of operational performance with a simultaneous decrease in average estimated plant core damage frequency. PRA applications have made a significant contribution to both plant safety and operational flexibility and performance.
	<br><br>		<br><br>
	[[File:cdf.png]]		[[File:cdf.png]]

Admin: /* Scope */

2025-01-17T21:35:11Z

Scope

← Older revision		Revision as of 21:35, 17 January 2025
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	==Scope==		==Scope==
	Probabilistic Risk Assessment (PRA) is a required part of the risk informed license following the [https://www.osti.gov/biblio/7134131 WASH-1400 Study] [[References\|[1]]] due to its proven benefits as applied to water reactors over the past 40 years. PRA technology and its applications have given rise to the development, not only of risk-informed applications, but also risk-informed regulation over a period of about 30 years. This has been a rapid transition from a narrow and highly technical field to daily use of PRA in plant operations and regulation at present. The scope of this effort is to investigate the historical aspects of risk technology, regulation and guidance for its applicability to advanced designs. Since advanced reactor / non-LWR designs can vary quite drastically from the designs of current water reactors, creating guidance and specific requirements for a PRA equivalent of advanced reactors can pose challenges.		Probabilistic Risk Assessment (PRA) is a required part of the risk informed license following the [https://www.osti.gov/biblio/7134131 WASH-1400 Study] [[References\|[1]]] due to its proven benefits as applied to water reactors over the past 40 years. PRA technology and its applications have given rise to the development, not only of risk-informed applications, but also risk-informed regulation over a period of about 30 years. This has been a rapid transition from a narrow and highly technical field to daily use of PRA in plant operations and regulation at present. The scope of this effort is to investigate the historical aspects of risk technology, regulation and guidance for its applicability to advanced designs. Since advanced reactor / non-LWR (not water cooled) designs can vary quite drastically from the designs of current water reactors, creating guidance and specific requirements for a PRA equivalent of advanced reactors can pose challenges.

	==Historical Background==		==Historical Background==

Admin: /* Scope */

2025-01-17T21:33:56Z

Scope

← Older revision		Revision as of 21:33, 17 January 2025
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	==Scope==		==Scope==
	Probabilistic Risk Assessment (PRA) is a required part of the risk informed license following the [https://www.osti.gov/biblio/7134131 WASH-1400 Study] [[References\|[1]]] due to its proven benefits as applied to ~~light~~ water reactors ~~(LWRs)~~ over the past 40 years. PRA technology and its applications have given rise to the development, not only of risk-informed applications, but also risk-informed regulation over a period of about 30 years. This has been a rapid transition from a narrow and highly technical field to daily use of PRA in plant operations and regulation at present. The scope of this effort is to investigate the historical aspects of risk technology, regulation and guidance for its applicability to advanced designs. Since advanced reactor / non-LWR designs can vary quite drastically from the designs of current ~~LWRs~~, creating guidance and specific requirements for a PRA equivalent of advanced reactors can pose challenges.		Probabilistic Risk Assessment (PRA) is a required part of the risk informed license following the [https://www.osti.gov/biblio/7134131 WASH-1400 Study] [[References\|[1]]] due to its proven benefits as applied to water reactors over the past 40 years. PRA technology and its applications have given rise to the development, not only of risk-informed applications, but also risk-informed regulation over a period of about 30 years. This has been a rapid transition from a narrow and highly technical field to daily use of PRA in plant operations and regulation at present. The scope of this effort is to investigate the historical aspects of risk technology, regulation and guidance for its applicability to advanced designs. Since advanced reactor / non-LWR designs can vary quite drastically from the designs of current water reactors, creating guidance and specific requirements for a PRA equivalent of advanced reactors can pose challenges.

	==Historical Background==		==Historical Background==

Admin: /* Historical Background */

2024-07-10T15:52:58Z

Historical Background

← Older revision		Revision as of 15:52, 10 July 2024
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	*PRA for existing reactors includes Levels 1 to 3 for quantification of initiating events and all hazards, while for advanced reactors the quantification capability may vary from plant to plant.		*PRA for existing reactors includes Levels 1 to 3 for quantification of initiating events and all hazards, while for advanced reactors the quantification capability may vary from plant to plant.
	<br>		<br>
	A PRA model is required as part of the risk-informed licensing basis for new light water reactors (LWRs) under [https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/index.html Part 52 of 10 CFR] [[References\|[2]]] (NRC). For advanced reactor deployments, [https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-0034.html 10CFR50 section 34(f)(1)(i)~~] [[References\|[11]]~~] states that the license applicant is required to “Perform a plant/site specific probabilistic risk assessment, the aim of which is to seek such improvements in the reliability of core and containment heat removal systems that are significant and practical and do not impact excessively on the plant.” To address the large gap in the designs of current LWRs and advanced reactors, a standard that specifies requirements for developing a PRA for non-LWR advanced reactors, [https://www.asme.org/codes-standards/find-codes-standards/probabilistic-risk-assessment-standard-for-advanced-non-light-water-reactor-nuclear-power-plants/2021/pdf ASME/ANS RA-S-1.4-2021], has been developed. Since licensing and operation of these advanced reactors represent a first-of-a-kind (FOAK) application, the US nuclear industry developed guidance [https://www.nrc.gov/docs/ML1924/ML19241A472.pdf (NEI 18-04)] [[References\|[8]]] for a modern, technology-inclusive, risk-informed, and performance-based (TI-RI-PB) process.		A PRA model is required as part of the risk-informed licensing basis for new light water reactors (LWRs) under [https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/index.html Part 52 of 10 CFR] [[References\|[2]]] (NRC). For advanced reactor deployments, [https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-0034.html 10CFR50 section 34(f)(1)(i)] states that the license applicant is required to “Perform a plant/site specific probabilistic risk assessment, the aim of which is to seek such improvements in the reliability of core and containment heat removal systems that are significant and practical and do not impact excessively on the plant.” To address the large gap in the designs of current LWRs and advanced reactors, a standard that specifies requirements for developing a PRA for non-LWR advanced reactors, [https://www.asme.org/codes-standards/find-codes-standards/probabilistic-risk-assessment-standard-for-advanced-non-light-water-reactor-nuclear-power-plants/2021/pdf ASME/ANS RA-S-1.4-2021], has been developed. Since licensing and operation of these advanced reactors represent a first-of-a-kind (FOAK) application, the US nuclear industry developed guidance [https://www.nrc.gov/docs/ML1924/ML19241A472.pdf (NEI 18-04)] [[References\|[8]]] for a modern, technology-inclusive, risk-informed, and performance-based (TI-RI-PB) process.
	<br>		<br>
	Ongoing industry collaboration is intended to support the need for additional and expanded guidance.		Ongoing industry collaboration is intended to support the need for additional and expanded guidance.

Admin: /* Scope */

2024-07-09T18:34:21Z

Scope

← Older revision		Revision as of 18:34, 9 July 2024
Line 6:		Line 6:

	==Scope==		==Scope==
	Probabilistic Risk Assessment (PRA) is a required part of the risk informed license following the [https://www.osti.gov/biblio/7134131 WASH-1400 Study] [[References\|[1]]] due to its proven benefits as applied to LWRs over the past 40 years. PRA technology and its applications have given rise to the development, not only of risk-informed applications, but also risk-informed regulation over a period of about 30 years. This has been a rapid transition from a narrow and highly technical field to daily use of PRA in plant operations and regulation at present. The scope of this effort is to investigate the historical aspects of risk technology, regulation and guidance for its applicability to advanced designs. Since advanced reactor / non-LWR designs can vary quite drastically from the designs of current LWRs, creating guidance and specific requirements for a PRA equivalent of advanced reactors can pose challenges.		Probabilistic Risk Assessment (PRA) is a required part of the risk informed license following the [https://www.osti.gov/biblio/7134131 WASH-1400 Study] [[References\|[1]]] due to its proven benefits as applied to light water reactors (LWRs) over the past 40 years. PRA technology and its applications have given rise to the development, not only of risk-informed applications, but also risk-informed regulation over a period of about 30 years. This has been a rapid transition from a narrow and highly technical field to daily use of PRA in plant operations and regulation at present. The scope of this effort is to investigate the historical aspects of risk technology, regulation and guidance for its applicability to advanced designs. Since advanced reactor / non-LWR designs can vary quite drastically from the designs of current LWRs, creating guidance and specific requirements for a PRA equivalent of advanced reactors can pose challenges.


	==Historical Background==		==Historical Background==

Admin: /* Historical Background */

2024-07-09T18:33:14Z

Historical Background

← Older revision		Revision as of 18:33, 9 July 2024
Line 10:		Line 10:

	==Historical Background==		==Historical Background==
	In the current fleet of US ~~Light Water Reactors (~~LWRs), a measurable improvement of safety can be seen in the figure below which displays increasing plant capacity factors as a measure of operational performance with a simultaneous decrease in average estimated plant core damage frequency. PRA applications have made a significant contribution to both plant safety and operational flexibility and performance.		In the current fleet of US LWRs, a measurable improvement of safety can be seen in the figure below which displays increasing plant capacity factors as a measure of operational performance with a simultaneous decrease in average estimated plant core damage frequency. PRA applications have made a significant contribution to both plant safety and operational flexibility and performance.
	<br><br>		<br><br>
	[[File:cdf.png]]		[[File:cdf.png]]