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Meeting the new NRA standards won't be easy

February 28, 2013

Power companies to face tough new standards for nuke reactor restarts



Power companies across the country will apply for permission to reactivate around five nuclear reactors when new safety standards for nuclear power plants go into effect in July, it has been learned.

The new nuclear regulatory agency is expected to take several months after receiving reactivation applications to decide whether or not to give the go-ahead for utilities to restart their reactors. However, because the only reactors currently in operation in Japan -- Kansai Electric Power Co.'s Oi Nuclear Power Plant's No. 3 and No. 4 units -- will also be subject to the new standards, there is a chance that Japan could find itself with zero operating reactors once again.

The Mainichi Shimbun surveyed domestic power companies on steps they are taking toward fulfilling the new safety standards.

One of the key characteristics of the new safety standards includes the construction of new equipment and facilities, such as a second control room or other "designated safety facilities." Because the newly established Nuclear Regulation Authority (NRA) has not established detailed installation requirements, most utilities held off revealing their progress to the Mainichi, saying they are waiting for the NRA's specifications.

Meanwhile, Tokyo Electric Power Co. (TEPCO), which is hoping to reactivate its Kashiwazaki-Kariwa Nuclear Power Plant in Niigata Prefecture, indicated that it is in the midst of "deliberating a basic concept" for its adherence to the new requirements. Kyushu Electric Power Co., which is aiming to restart its Genkai and Sendai nuclear power plants, also said that it was "conducting specific deliberations." Power companies are expected to be given three to five years before the new facilities are made a requirement.

All the utilities have either finished building or are slated to build quake-proof facilities like the one that has served as a front-line emergency operations base in the Fukushima disaster. Shikoku Electric Power Co. finished its facility at Ikata Nuclear Power Plant in late 2011, fulfilling one criterion for reactor reactivation. The NRA has not yet decided whether it will give utilities individual deadlines on this criterion, but if that turns out to be the case, it could water down the effect of the new safety standards.

TECPO has begun work on installing filtered vent systems at the No. 1 and No. 7 reactors at Kashiwazaki-Kariwa. Chubu Electric Power Co. has also said it will begin the same work at Hamaoka Nuclear Power Plant soon, but predicts it will take two to three years to complete. The NRA plans to make filtered vents a requirement for boiling water reactors (BWRs) -- the same type as the reactors at the stricken Fukushima plant -- in July, at the time the new standards go into effect. This will make it difficult to resume operations of the 26 BWRs, located primarily in eastern Japan, at an early date.

Meanwhile, utilities will likely be allowed more time to install filtered vents on the 24 pressurized water reactors (PWRs) in Japan, found mostly in the western part of the country, since their containment vessels are relatively large and their furnace pressures take more time to rise than in BWRs.

The new safety standards also include more stringent measures against fire, including the use of flame-resistant cables. Currently, flammable cables are used in at least 13 reactors. Since about 1,000 to 2,000 kilometers' worth of cables are used per reactor, inspecting and replacing all of them is bound to take a significant amount of time.

The stipulation that limits a reactor's operational life to 40 years is also expected to make it into the new standards. Three of Japan's reactors began operations over 40 years ago, and 14 have been in operation for over 30. If the rule is strictly applied, some reactors are likely to be decommissioned. Chugoku Electric Power Co. is weighing the cost-effectiveness of installing filtered vents on the No. 1 reactor at its Shimane Nuclear Power Plant, which began operations 39 years ago, saying, "We'll consider the specifics of the 40-year rule in making our decision."

When the power companies were asked whether they had any requests for the NRA, Kansai Electric Power Co. responded, "We'd like (the NRA) to exchange ideas with the utilities."

Meanwhile, rules on active faults on plant properties were completely revamped under the new safety standards' quake and tsunami measures. Faults were heretofore inspected for any activity in the last 120,000 to 130,000 years. Starting in July, if no activity is detected within that time, the fault must be inspected for activity in the last 400,000 years.

Under the new standards, the construction of important facilities above active faults will be explicitly prohibited by law for the first time. The NRA will also demand the construction of coastal levees based on data on the biggest possible tsunami that could strike each of the country's reactors.

Following further deliberation by the NRA on the 40-year operation rule and deadlines for the new requirements, the new safety standards will be legislated and go into effect by July 18.

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