Security lapses impact Kashiwazaki-Kariwa restart

17 March 2021

Tokyo Electric Power Company (Tepco) has failed in its duty to protect nuclear materials at its Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture, according to Japan's Nuclear Regulation Authority (NRA). A series of security breaches has prompted the regulator to suspend the process for inspections needed to restart unit 7 at the plant.

Kashiwazaki-Kariwa (Image: Tepco)

On 27 January this year, Tepco notified the NRA that a contractor has accidently damaged intruder detection equipment at the Kashiwazaki-Kariwa site. The company informed the regulator on 12 February that some of the functions related to this equipment had been repaired. However, at that time Tepco said it had found malfunctions in intruder detection equipment at 12 locations on the site and that alternative measures had been implemented. Tepco informed the NRA of three further locations experiencing equipment malfunctions over the following week.

The NRA carried out three inspections at the Kashiwazaki-Kariwa plant between 21 February and 4 March. It concluded the alternative measures introduced by Tepco "have not been effective at multiple locations since March 2020, thereby resulting in a long period of time during which unauthorised intruders cannot be detected, and this situation has not been rectified". Tepco did not rectify the problem, the NRA said, even though its security guards were aware the alternative measures were ineffective and, as a result, it may have been impossible to detect intruders for more than 30 days. "The company is not fully aware that these circumstances exist," it added.

The NRA informed Tepco yesterday that a preliminary assessment had rated the significance of these security lapses as "red" - the highest level on its four-point scale of risks in safeguarding nuclear material. This rating implies a large impact on safety functions or performance.

"Organisational management functions at the Kashiwazaki-Kariwa nuclear power station have declined to the point that the effectiveness of security measures has not been appropriately ascertained for a long period of time, thereby resulting in the potential for a serious incident pertaining to nuclear material protection," the NRA said.

Tepco said it is taking the NRA's assessment "very seriously" and it "will quickly respond" to the regulator.

"As a nuclear operator, ensuring nuclear security is one of Tepco's most important responsibilities. Unfortunately, we have experienced a rash of nuclear material protection-related incidents at the Kashiwazaki-Kariwa nuclear power station since the unauthorised use of an ID card last year," it said. "We would like to deeply apologise for the concern we have caused amongst regional residents, and society as a whole, as a result of these incidents."

Tepco noted it informed the NRA on 5 March that repairs had been made to all the malfunctioning equipment. It also confirmed that no unauthorised access has been found to have occurred at the affected locations. "Furthermore, we have put in place a system for implementing effective substitute measures to counteract any new malfunctions of nuclear material protection equipment."

Pre-use inspections

As a result of the security lapses, the NRA has decided to "suspend for the time being" its pre-use inspections, which are required for Tepco to load fuel into Kashiwazaki-Kariwa unit 7.

"We are keeping Tepco's move toward the restart on hold in our continuing series of inspections until the company is allowed to start commercial operation of the reactor," NRA Chairman Toyoshi Fuketa was quoted as saying today by the Asahi Shimbun. An additional inspection of the site will take "at least more than a year even if it proceeds at an extremely fast pace", he added.

Although it has completed work at the other idled units at Kashiwazaki-Kariwa, Tepco is concentrating its resources on units 6 and 7 while it deals with the clean-up at Fukushima Daiichi. Restarting those two units - which have been offline for periodic inspections since March 2012 and August 2011, respectively - would increase the company's earnings by an estimated JPY100 billion (USD916 million) per year.

Tepco applied for NRA approval of its design and construction plan for Kashiwazaki-Kariwa units 6 and 7 in September 2013. It submitted information on safety upgrades across the site and at those two units. These 1356 MWe Advanced Boiling Water Reactors began commercial operation in 1996 and 1997 and were the first Japanese boiling water reactors to be put forward for restart.

Researched and written by World Nuclear News