Power Reactors (Division 1): Regulatory Guides 1.21 - 1.40

This page lists the number, title, publication date, and revisions for each regulatory guide in Division 1, "Power Reactors," with references to draft guides and related documents (where applicable).

See NRC Regulatory Guides for more general information.

Regulatory Guides are reviewed about every 10 years, although a guide may be reviewed more frequently if the staff believes an emerging issue affects the guide. The NRC began these reviews in 2010, and began posting the results of its reviews on this site in 2013. The review dates are hyperlinked to the review memorandum, which provide useful information about the status and any known issues with the associated regulatory guide.

Guide Number	Title	Revision Number	Publish Date	Additional Information
1.21	Measuring, Evaluating, and Reporting Radioactive Material in Liquid and Gaseous Effluents and Solid Waste HISTORY 01/2021 – DG-1377 issued as proposed Revision 3 09/2019 – Periodic Review performed recommended revising 03/2015 – Periodic Review of Revision 2 – Issues identified for future consideration 10/2008 – DG-1186 issued as proposed Revision 2 12/1971 – Atomic Energy Commission issued Safety Guide 21, "Measuring and Reporting of Effluents from Nuclear Power Plants," which is the predecessor of RG 1.21, Rev. 1	3	09/2021
		2	06/2009
		1	06/1974
		0	12/1971
1.22	Periodic Testing of Protection System Actuation Functions (Safety Guide 22) HISTORY 03/2022 - Periodic Review - Reviewed with no issues identified 08/2012 - Periodic Review - Reviewed with no issues identified 02/1972 - RG 1.22 Revision 0	0	02/1972	Periodic Review in 2022 Reviewed with no issues identified Periodic Review in 2012 – Reviewed with no issues identified
1.23	Meteorological Monitoring Programs for Nuclear Power Plants HISTORY 03/2023 - Periodic Review - Reviewed with issues identified for future consideration 03/2013 - Periodic Review - Reviewed with issues identified for future consideration 03/2007 - RG 1.23 Revision 1 DG-1164, Third Proposed Revision 1, published 10/2006 Draft ES 926-4, Second Proposed Revision 1, entitled "Meteorological Measurement Program for Nuclear Power Plants," published 04/1986 Draft SS 926-4, First Proposed Revision 1, entitled "Meteorological Programs In Support of Nuclear Power Plants," published 09/1980 Revision 0, entitled "Onsite Meteorological Programs," was issued as Safety Guide 23	DG	07/2026	DG-1463
		1	03/2007	Periodic Review in 2023 Reviewed with issues identified for future consideration Periodic Review in 2013 – Reviewed with issues no issues identified
		0	02/1972
1.24	Assumptions Used for Evaluating the Potential Radiological Consequences of a Pressurized Water Reactor Radioactive Gas Storage Tank Failure (Safety Guide 24) HISTORY 06/2026 - Periodic Review - Reviewed with issues identified for future consideration 02/2016 - Periodic Review - Reviewed with issues identified for future consideration 03/1972 - RG 1.23 Revision 0	0	03/1972	Periodic Review in 2026 - Reviewed with issues identified for future consideration Periodic Review in 2016 – Reviewed with issues identified for future consideration
1.25	Assumptions Used for Evaluating the Potential Radiological Consequences of a Fuel Handling Accident in the Fuel Handling and Storage Facility for Boiling and Pressurized Water Reactors (Safety Guide 25) (Withdrawn – See 81 FR 89510, 12/12/2016)	W	12/2016
1.25		0	03/1972
1.26	Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants HISTORY DG 1371, Proposed Revision 6, published 04/2021 DG-1314, Proposed Revision 5, published 04/2015 DG-1152, Proposed Revision 4, published 11/2006 Revision 3 was issued for public comment on 02/1976	6	12/2021
		5	02/2017
		4	03/2007
		3	02/1976
		2	06/1975
		1	09/1974
		0	03/1972
1.27	Ultimate Heat Sink for Nuclear Power Plants HISTORY DG-1275, Proposed Revision 3, published 09/2013	3	11/2015
		2	01/1976
		1	03/1974
		0	03/1972
1.28	Quality Assurance Program Criteria (Design and Construction) HISTORY DG-1403, Proposed Revision 6, published 04/2023 DG-1326, Proposed Revision 5, published 03/2017 DG-1215, Proposed Revision 4, published 07/2009 Prior to the issuance of Revision 4, RG 1.28 was entitled “Quality Assurance Program Requirements (Design and Construction)”	6	09/2023
		5	10/2017
		4	06/2010
		3	08/1985
		2	02/1979
		1	03/1978
		0	06/1972
1.29	Seismic Design Classification for Nuclear Power Plants HISTORY DG-1315, Proposed Revision 5, published 09/2015 DG-1156, Proposed Revision 4, published 10/2006	6	07/2021
		5	07/2016
		4	03/2007
		3	09/1978
		2	02/1976
		1	08/1973
		0	06/1972
1.30	Quality Assurance Requirements for the Installation, Inspection, and Testing of Instrumentation and Electric Equipment (Safety Guide 30) HISTORY 08/2022 - Periodic Review - Revise 12/2018 - Periodic Review - Revise 12/2023 DG-1419, Proposed Revision 1	1	04/2024
1.30		0	08/1972	Periodic Review in 2022 – Revise Periodic Review in 2018 – Revise
1.31	Control of Ferrite Content in Stainless Steel Weld Metal HISTORY 01/2026, Periodic Review – Reviewed with no issues identified 04/2016, Periodic Review – Reviewed with no issues identified	4	10/2013	Periodic Review in 2026 – Reviewed with no issues identified Periodic Review in 2016 – Reviewed with no issues identified
		3	04/1978
		2	05/1977
		1	06/1973
		0	08/1972
1.32	Criteria for Power Systems for Nuclear Power Plants HISTORY 01/2025 - RG 1.32 Revision 4 DG-1420, Proposed Revision 4, published 08/2024 04/2017 - Periodic Review - Reviewed with no issues identified 01/2025 - RG 1.32 Revision 3 DG-1079, Proposed Revision 3, published 04/2003	4	01/2025
		3	03/2004	Periodic Review in 2017 – Reviewed with no issues identified
		2	02/1977
		1	03/1976
		0	08/1972
1.33	Quality Assurance Program Requirements (Operation) HISTORY 07/2023 - Periodic Review - Reviewed with issues identified for future consideration 06/2013 - RG 1.33 Revision 3 DG-1300, Quality Assurance Program Requirements (Operations), published 02/2013 Draft RS 902-4, Second Proposed Revision 3, published 11/1980 Draft RS 902-4, First Proposed Revision 3, published 08/1979 02/1978 - RG 1.33 Revision 2 01/1977 - RG 1.33 Revision 1 11/1972 - RG 1.33 Revision 0	3	06/2013	Periodic Review in 2023 - Reviewed with issues identified for future consideration
		2	02/1978
		1	01/1977
		0	11/1972
1.34	Control of Electroslag Weld Properties HISTORY 01/2026 – Periodic Review – Reviewed with no issues identified 04/2016 – Periodic Review – Reviewed with no issues identified 03/2011 – RG 1.34 Revision 1 DG-1223, Proposed Revision 1, published 06/2009. 12/1972 – RG 1.34 Revision 0	1	03/2011	Periodic Review in 2026 – Reviewed with no issues identified Periodic Review in 2016 – Reviewed with no issues identified
1.34		0	12/1972
1.35	Inservice Inspection of Ungrouted Tendons in Prestressed Concrete Containments (Withdrawn – See 80 FR 52067, 08/27/2015) HISTORY 08/2015 – RG 1.35 is withdrawn by 80 FR 52067, 08/27/2015 07/1990 – RG 1.35 Revision 3 04/1979 – Draft SC 810-4, Proposed Revision 3 01/1976 – RG 1.35 Revision 2 06/1974 – RG 1.35 Revision 1 02/1973 – RG 1.35 Revision 0	W	08/2015
		3	07/1990
		2	01/1976
		1	06/1974
		0	02/1973
1.35.1	Determining Prestressing Forces for Inspection of Prestressed Concrete Containments HISTORY 01/2015 - Periodic Review - Reviewed with issues identified for future consideration 07/1990 - RG 1.35.1 Revision 0 Draft SC 807-4, Proposed Revision 0, published 04/1979	0	07/1990	Periodic Review in 2015 – Reviewed with issues identified for future consideration
1.36	Nonmetallic Thermal Insulation for Austenitic Stainless Steel HISTORY 05/2025 - Periodic Review - Reviewed with issues identified for future consideration 05/2015 - RG 1.36 Revision 1 DG-1312, Proposed Revision 1, published 09/2014 02/1973 - RG 1.36 Revision 0	1	05/2015	Periodic Review in 2025 - Reviewed with Issues Identified for Future Consideration
1.36		0	02/1973
1.37	Quality Assurance Requirements for Cleaning of Fluid Systems and Associated Components of Water-Cooled Nuclear Power Plants (Withdrawn – See 79 FR 38963, 07/09/2014) HISTORY DG-1165, Proposed Revision 1, published 10/2006	W	07/2014
		1	03/2007
		0	03/1973
1.38	Quality Assurance Requirements for Packaging, Shipping, Receiving, Storage, and Handling of Items for Water-Cooled Nuclear Power Plants (Withdrawn – See 75 FR 54921, 09/09/2010)	W	09/2010
		2	05/1977
		1	10/1976
		0	03/1973
1.39	Housekeeping Requirements for Water-Cooled Nuclear Power Plants (Withdrawn – See 75 FR 70044, 11/16/2010)	W	11/2010
		2	09/1977
		1	10/1976
		0	03/1973
1.40	Qualification of Continuous Duty Safety-Related Motors for Nuclear Power Plants HISTORY 04/2026 – Periodic Review – Revise 12/2015 – Periodic Review – Reviewed with no issues identified 02/2010 – RG 1.40 Revision 1 08/2009 – DG-1150, Proposed Revision 1 03/1973 – RG 1.40 Revision 0	1	02/2010	Periodic Review in 2026 – Revise Periodic Review in 2015 – Reviewed with no issues identified
1.40		0	03/1973

Page Last Reviewed/Updated Tuesday, August 11, 2026

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Power Reactors (Division 1): Regulatory Guides 1.21 - 1.40