JAPAN ATOMIC INDUSTRIAL FORUM, INC.

for Japanese

ATOMS in JAPAN

3 April, 2019

Hitachi-GE, IRID Develop Boat-type Submersible Devices to Investigate PCV Interior at Fukushima Daiichi-1

On March 28, Japan’s Hitachi-GE Nuclear Energy and the International Research Institute for Decommissioning (IRID) announced their joint development of a series of boat-type submersible devices to investigate the interior of the primary containment vessel (PCV) of the Fukushima Daiichi-1, in anticipation of the removal of fuel debris from it.

Hitachi-GE chief engineer Yoshio Nonaka explains the submersible ROV-A (being used to install a guide ring)

On the same day, the devices were shown to the press at the Hitachi-GE Rinkai Factory.

Investigations conducted inside the PCV at the Fukushima Daiichi-1 in March 2017 revealed sediment accumulating in the water at the basement level of the pedestal (the bottom part of the reactor pressure containment vessel).

Expecting to use them in the first half of FY19 (April to September 2019), Hitachi-GE and IRID worked to develop the boat-type submersible devices to increase the understanding of the nature of the debris, as well as the effects of debris removal, among other matters.

Developed this time were five cylindrical submersible devices (each measuring approximately 25cm in diameter and 110cm long) and a small box-type boat (measuring approximately 18cm high, 20cm wide and 45cm long).

The submersible devices are equipped with various sensors used in different steps as the work progresses, as follows:

— Installation of a guide ring (to prevent cables to the devices from getting caught in existing equipment).

— 3D mapping of sediment.

— Measurement of the sediment thickness.

— Detection of fuel debris.

— Sampling of sediment.

The small boat, meanwhile, is equipped with both telephoto and wide-angle lenses for visual observation, enabling a grasp of the entire situation at the site, in preparation for subsequent data acquisition and sampling.

Operators are being trained at a mock-up of an actual plant prior to the deployment of the submersible devices and the boat.

On March 28, at a monthly press conference to report on the state of decommissioning progress, President Akira Ono of the Fukushima Daiichi Decontamination & Decommissioning Engineering Company was asked about future fuel removal.

Saying that it was important to develop devices based on individual plant characteristics, he stated in his response that before the end of the current fiscal year (that is, by March 2020), the company would clearly identify the first unit from which fuel debris would be removed according to the work schedule described in the medium- to long-term roadmap toward the decommissioning.

Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

SNS facebooktwitter

NPPs Map

Video

“The current situation at Fukushima Daiichi NPS” -From 3.11 toward the future- (ver, July 2019)

8 July, 2019
“The current situation at Fukushima Daiichi NPS” -From 3.11 toward the future- (ver, July 2019)09:17

Recent News

15 November, 2019
JAEA Holds Public Meeting, Discusses Future Vision, Fukushima Reconstruction and Revitalization
15 November, 2019
IAEA/RCA Symposium: Cooperating with Developing Countries Through Nuclear Science and Technology
8 November, 2019
EU to Ease Restrictions on Japanese Food Imports, Though Chief Cabinet Secretary Suga Asserts Japan Will Work Toward Their Full Elimination
28 October, 2019
OCCTO’s Electricity Supply and Outlook for Winter Sees Capacity Reserve Margin of 3 Percent Nationwide
23 October, 2019
Symposium with Students Held in Tsuruga City on Future Research and Test Reactors
17 October, 2019
JAIF Holds Women’s Symposium, with Presentations by Weathercaster and Professor
7 October, 2019
Fukushima Joban Products Fair Begins, Featuring Seafood Sent Directly to Restaurants in Tokyo-Yokohama Area
3 October, 2019
Kindai University, Hayakawa Rubber Develop Easily-molded Radiation Shielding Material
30 September, 2019
MEXT Minister Shares His Hopes with the Press, Seeking to Secure Human Resources Together with Universities
19 September, 2019
Minister of State for Science and Technology Policy Attends Opening Ceremony of Japan Booth at IAEA General Conference
▲TOP