OHP Sheets in the FY 1990 internal meeting on advanced nuclear-energy system research

; Nomura, Norio; Seino, Hiroshi; *

PNC TN9430 91-005, 112 Pages, 1991/03

PNC-TN9430-91-005.pdf:3.49MB

This paper complies OHP sheets used in the FY 1990 internal meeting on advanced nuclear-energy system research at O-arai Engineering Center, PNC on January 17, 1991. The frontier research which seeks innovative fast reactor and its new field of application includes [1]research submersible reactor, [2]hydrogen production reactor, [3]transportable reactor, and [4]lunar base reactor. Followings are the main topics presented in the meeting. ([1]Research submersible reactor) This type of a reactor might be used for deep sea development. The reactor will be built on the deep sea floor or will be set as a power source in a research submersible. A reactor vessel and a heat exchanger are set at the bottom region in a pressure hull. A radiation shield and a secondary system containing coolant gas are arranged above them. A closed Brayton cycle is used for electric power generation. For a nuclear reactor used for the submersible, one of the key issues is how to exhaust heat unused for clectric power generation. Here, it is proposed to exhaust the heat by using a cooling system set inside the pressure hull. Heat is transferred from the outer surface of the hull to sea water by thermal convection. The sea water is moved by a fan under the hull and flows upward over the surface of the hull. A preliminary heat transfer calculation has been performed assuming that the shape of the hull is a pipe of 3 m in inner diameter and 6 m in height. The cooling system is set inside its inner surface area of 63.6 m. The thickness of the hull wall is 7.6410 m for the 6,500 m research submersible. The material of the hull is high tension steel, or titanium alloy. Width of a coolant gas passage is 810 m in the cooling system. The electric power of the reactor is 100 to 300 kWe. The power conversion efficiency of the reactor and the closed Brayton cycle is 17%. A heat transfer coefficient is assumed to be increased about 40 % by setting fins over ...