Document: NUREG-0800
Document ID: 217f75d5-3db3-41ce-939d-8f7a5fcf0f68
Document Type: srp
Title: feet 0.76 m (2.5 ft).   The applicant in Section 2.4.12 of the PSAR has described the
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070262.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5
CFR Part: 
CFR Title: 

Content:
ect way of inspecting them, reliance must be placed on piezometers, observation wells, manholes, and monitoring of collected water to detect problems or malfunctioning of the system. The details of an operational monitoring program are necessary prior to construction of the underdrain to assure ensure that each of the following will be provided: (1) an early detection alarm system during normal operating conditions; (2) regularly scheduled inspection and monitoring; and (3) competent evaluation of observations during both construction and operation. In addition, the bases for acceptable contingency measures suitable for coping with various possible hazards must be established at the CP or early site permit stage. 57 (c) Pipe Breaks A dewatering system might be overloaded by such conditions as leaks or breaks in either the circulating or service water systems. A leak through a pipe break may be a very small percentage of the total flow of the cooling water system, but large enough to exceed the hydraulic capacity of drains, pipes, and pumps in the dewatering system. For example, a complete failure of circulating water system piping has been required in the design of the dewatering systems reviewed to date. This requirement was made to assure ensure that such abnormal occurrences do not adversely affect the integrity of safety-related structures, systems, and components. (d) Sequence of Review DRAFT Rev. 3 - April 1996 2.4.12-18 Underdrain systems are usually one of the first items constructed and, after backfilling and construction of subsurface facilities, are then no longer visible for regular inspection. In most cases, these systems are initially designed based on rather limited information from preconstruction field activities, and are tailored specifically for the site and facilities. By necessity then, final review and approval by the staff of the design must rely in some part on information gathered during construction. Therefore, the review and approval can