Document: NUREG-0800
Document ID: d6f7c640-9c89-4c04-a929-3caac89cdb95
Document Type: srp
Title: EMERGENCY DIESEL ENGINE COOLING WATER SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350039.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.5
CFR Part: 
CFR Title: 

Content:
Failure of a piping interconnection, as shown on system piping and instrumentation diagrams (P&IDs), between subsystems does not cause total degradation of the EDECWS. The results of failure modes and effects analyses are used as a basis of acceptance. c. Provisions have been made to permit inspection of components, as shown on system layout drawings. d. The performance and water chemistry of the EDECWS is in conformance with the engine manufacturer's recommendations. e. The engine "first try" starting reliability has been increased by providing an independent loop for circulating heated water while the engine is in the standby mode. f. A three-way bypass-type thermostatically controlled valve has been provided to control water flow through the jacket water coolers or radiators so that proper coolant temperature is maintained at the engine inlet, as specified by the manufacturer. g. Temperature sensors have been provided to alert the operator when cooling water temperatures exceed the limits recommended by the manu- facturer. Protective interlocks in this system are acceptable if the SAR indicates that the interlocks are in conformance with Branch Technical Position ICSB-17 (PSB). 2. The reviewer verifies that the EDECWS can be vented to assure that all spaces are filled with water. Statements in the SAR to the effect that the system design satisfies the above requirement are acceptable. .3. The reviewer verifies that system function will be maintained in the event of adverse environmental phenomena and loss of offsite power. The reviewer evaluates the system, using engineering judgment.and the results of failure modes and effects analyses to determine that: a. Failure of nonessential portions of the system or the other systems not designed to seismic Category I requirements and located close to essential portions of the'system, or of nonseismic Category I structures that house, support, or are close to essential portions of the EDECWS, will not preclude essential