A lead-bismuth cooled small reactor named CLEAR-SR have been proposed, the main purpose of the reactor is for energy supply in the ocean environments, such as the islands far from the land or offshore oil drilling platform. CLEAR-SR with integrated modular design, the power would to be 50-100 MWe, makes use of UN (U-235enrichment is 19.75%) as fuel, stainless steel as cladding and structure, can full power operation more than 10 years without refueling, the life of the reactor would be 60 years. Safety aspects of CLEAR-SR are most concerned, CLEAR-SR can achieve deep negative feedback factor in operation, all of reactor vessel is below the sea level which can use the sea water as reactor vessel coolant in accident and make the reactor more stable in the harsh marine environment, the reactor vessel have double layer e.g. main vessel and safety vessel, use passive residual heat removal system, etc. The preliminary conceptual design of CLEAR-SR will be presented in this paper, detail design options will be discussed and R&D requirements will be specified. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.