Jun-ichi Nishizawa pioneered technologies that became fundamental to optical communications, yet encountered resistance from Japan’s patent administration.
Japan also reached criticality with the Monju prototype fast breeder reactor ahead of Russia’s BN-800, only to place Monju into decommissioning after years of controversy, operational interruption and hostile reporting.
Through Masayuki Takayama’s critique, this article asks how bureaucracy and the media have repeatedly obstructed Japan’s original scientific and technological achievements.

This article was first published on January 17, 2020, and republished on August 3 of the same year.
The latter portion quotes an essay by Masayuki Takayama from his Shukan Shincho column Henken Jizai.
Takayama examined Jun-ichi Nishizawa’s optical-communications research and the Monju prototype fast breeder reactor and criticized the role played by Japan’s administrative institutions and news media in frustrating original Japanese technologies.
A collection of Takayama’s columns published by Shinchosha includes an essay entitled “Decommissioning Monju Will Crush Japan’s Intellectual Strength.”
The article remains important in 2026 because Japan did not abandon fast-reactor technology when it decided to decommission Monju.
In 2023, the government selected the sodium-cooled pool-type fast reactor proposed by Mitsubishi FBR Systems as the design concept for Japan’s demonstration reactor and chose Mitsubishi Heavy Industries as the core company.
A June 2026 document issued by the Agency for Natural Resources and Energy identifies the mid-2040s as the earliest target for operation of the demonstration fast reactor.
Japan is therefore attempting to rebuild, over several decades, a technological path that Monju had already begun to establish.
The article asks what caused that loss of time.
Key Quotation
“The world began the race at the same starting signal, and Japan achieved first criticality in 1994. Russia came second, bringing its reactor into operation only recently. This shows how far Japan had advanced, but shortly after Monju began operating—”
Full Text
August 3, 2020
The world began the race at the same starting signal, and Japan achieved first criticality in 1994.
Russia came second, bringing its reactor into operation only recently.
This shows how far Japan had advanced, but shortly after Monju began operating—
I am republishing the chapter first issued on January 17, 2020, under the title: “Unlike a Light-Water Reactor, a Coolant Leak Was No More Than Spilling Coffee—Monju Was Sentenced to Decommissioning by Lies and Excessive Reporting.”
The following explains why.
I now either watch NHK news only in passing or skip it altogether.
In particular, I truly do not want to watch News Watch 9.
The other night, however, I happened to see it.
It reported in a negative tone while explaining almost nothing about the information contained on the Agency for Natural Resources and Energy’s page concerning the fast-reactor strategic roadmap.
What I found amusing was the expression of Arima, who presumably wanted to argue against nuclear power.
Perhaps senior management had finally warned him about excessively arbitrary reporting.
He appeared desperate to make an anti-nuclear comment but was forcing himself, with a childlike expression, to hold back what he wanted to say.
Even when reporting on the Monju accident, they provide no concrete explanation and merely refer to “repeated accidents.”
They are the real villains.
They are all the more malicious because they speak as though they represent good sense or are conveying the truth.
The preceding passage is omitted.
In the year of the Tokyo Olympics, Tohoku University Professor Jun-ichi Nishizawa applied for a patent covering a revolutionary optical-communications technology.
The Japan Patent Office returned the application, claiming that its format was defective and its meaning incomprehensible.
Nishizawa resubmitted it twenty times, but each time another pretext was found for rejecting it.
He also took the matter to court, but after twenty years of struggle, the patent application was never accepted.
At around the same time, Charles Kao, a Chinese scientist acquainted with Nishizawa, went to the United States and published a paper presenting the same idea as Nishizawa’s.
He later received a Nobel Prize for that work.
The American company Corning also obtained patents through Kao for technology closely resembling Nishizawa’s.
Corning used those patent rights to sue Sumitomo Electric, which had adopted the Nishizawa method, for patent infringement and won decisively.
It was a perfect example of Japanese officials destroying Japanese intellectual achievement through their own incompetence.
The fast breeder reactor Monju, once described as a dream reactor, was effectively condemned to decommissioning.
The world began the race at the same starting signal, and Japan achieved first criticality in 1994.
Russia came second, bringing its reactor into operation only recently.
This shows how far Japan had advanced, but shortly after Monju began operating, an incident occurred in which sodium used as a coolant leaked.
Unlike a light-water reactor, the coolant leak was no more serious than spilling coffee.
The timing, however, was unfortunate.
The foolish Tomiichi Murayama was prime minister, and the Asahi Shimbun behaved as though it were the Chief Cabinet Secretary.
Asahi screamed against nuclear power and drove two people involved to suicide.
On that day, Japan’s most advanced technology was sentenced to decommissioning by lies and excessive reporting.
The Japan Patent Office was not alone in crushing Japanese intellectual achievement.
An even more foolish newspaper had joined it.
What, then, should Japan do now?
Asahi is likely to offer the pompous recommendation that Japan should proceed slowly with joint development alongside second-rate France.
Second place is good enough, is it?
What are you, Renho?
Notes on Sources and Terminology
The original Japanese text dated August 3, 2020, has been reproduced without alteration.
A Tohoku University publication confirms that Nishizawa filed a patent application relating to optical fiber in 1964 under application number Sho 39-64040.
It also states that his proposal preceded Kao’s 1966 paper.
Kao received the 2009 Nobel Prize in Physics for groundbreaking achievements concerning the transmission of light in fibers for optical communication.
The original statement that Kao “went to the United States” is inaccurate.
His principal research institution during the relevant period was Standard Telecommunication Laboratories in Harlow, United Kingdom.
The Corning litigation against Sumitomo Electric was real, and United States courts upheld findings that Sumitomo had infringed certain valid Corning optical-fiber patents.
The judgments did not, however, determine that Corning had obtained the patented technology from Nishizawa through Kao.
Monju achieved first criticality on April 5, 1994, and first supplied electricity to the grid on August 29, 1995.
On December 8, 1995, a thermowell in the secondary cooling system failed, releasing an estimated 640 kilograms of sodium.
The secondary-system sodium was not radioactive, and no radiological effects upon workers or the surrounding public occurred.
Sodium is nevertheless highly reactive in contact with air and water, and oxidation and fire occurred.
Takayama’s comparison with spilled coffee is therefore a polemical metaphor emphasizing the absence of radioactive release, not a literal technical assessment of the chemical hazard.
Russia’s BN-800 achieved first criticality in June 2014, was first connected to the grid in December 2015 and entered commercial operation in October 2016.
The formal decision to place Monju into decommissioning was made on December 21, 2016, twenty-one years after the sodium-leak accident.
Monju had resumed performance testing in May 2010, but subsequent equipment problems, overdue inspections, deficiencies in maintenance planning, governance failures, regulatory requirements and the projected cost and time required for another restart contributed to the final government decision.
Japan has not abandoned sodium-cooled fast-reactor technology.
The present program aims to develop a demonstration reactor with operation beginning, at the earliest, around the middle of the 2040s.

2016年10月6日号）