Document: NUREG-0800
Document ID: ba447c99-c09a-4d8c-84cd-804a2261f17c
Document Type: srp
Title: MAINTENANCE RULE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0729/ML072920088.pdf
Revision Date: 2023-06
Chapter: 17
Section ID: 17.6
CFR Part: 
CFR Title: 

Content:
nse is issued. The description of the MR scoping process should address: | A. The criteria for including safety-related SSCs relied upon to remain functional | during and following design-basis events in accordance with 50.65(b)(1). | B. The criteria for including nonsafety-related SSCs in accordance with 50.65(b)(2) | (i) The accidents or transients referred to in 50.65(b)(2)(i) are those | described in the FSAR. (ii) SSCs that are “used in plant emergency operating procedures (EOPs)” in | accordance with 50.65(b)(2)(i), are as described in Paragraph 1.1.2 of | RG 1.160, Revision 2. This differs from the corresponding description in | NUMARC 93-01, Revision 2. The applicant’s program should reflect the | description in RG 1.160, Revision 2, until this description, currently under | review for revision, is changed in a future revision of NUMARC 93-01 and | RG 1.160. The latest revision of RG 1.160 in effect at the time of the | COL application should be followed. | | NOTE: The NRC’s interpretation of the meaning of the phrase “used in | ...EOPs” is explained in the statements of considerations for the MR and | will be amplified and clarified in a future revision to RG 1.160; this is | expected to be reflected in a future revision to NUMARC 93-01. The | amplified and clarified definition is expected to be similar to the following: | 17.6-5 Revision 1 - August 2007 SSCs used in the EOPS that are required to be in the scope of the MR | program are those that (1) are directly used to mitigate accidents or | transients (explicitly mentioned in the EOPs or in steps of referenced procedures needed to accomplish the EOP step), (2) have mitigating functions explicitly mentioned in backup or lower-tier methods in the EOPS that provide reasonable assurance of successful accomplishment of a mitigation function (as may be determined through risk-informed methods) and (3) those whose use is implied and that are essential to the | performance of one or more EOP steps