More on the Japan Quake and the Kashiwazaki-Kariwa Nuclear Plant

The following report comes from our friends at NucNet:

There was no environmental impact as a result of yesterday’s automatic shut-down of three units at Japan’s Kashiwazaki Kariwa nuclear power plant following an earthquake.

The Japan Atomic Industrial Forum (JAIF) today confirmed for NucNet that units 3, 4 and 7 of the plant, in Niigata prefecture in the west of the country, shut down safely. The plant’s other units – Kashiwazaki Kariwa-1, -2, -5 and -6 – were already shut down at the time of the earthquake for periodic inspections.

At unit 6, about 1.2 cubic metres of water leaked from a system draining water to the sea, but the level of radioactivity was within the permissible limit. Inside the reactor building, a total of 1.5 litres of radioactive aqueous liquids were spilled.

At unit 3, a fire broke out in a main transformer in the non-nuclear part of the plant and was extinguished within two hours.

A JAIF spokesman said: “The cloud of black smoke that was filmed by television crews did scare some people watching television. But it was a small fire and there was no release of radioactivity or environmental impact.” No other Japanese units were affected by the quake, said the spokesman.

Just this morning, we received the following report via the AP:

On Tuesday, officials said about 100 drums containing low-level nuclear waste fell over at the plant during the quake. They were found a day later, some with their lids open, said Masahide Ichikawa, an official with the local government in Niigata prefecture.

A spokesman at Tokyo Electric Power Co., which runs the plant, said the company was still trying to determine whether any hazardous material had spilled but said there was no effect outside the plant.

Definitions are important here. When you hear the term, "low-level radioactive waste" it refers to solid materials that have been exposed to radiation during normal operations of the plant. According to an article on the NEI Web site:

Low-level waste is solid material. It generally has levels of radioactivity that decay to background radioactivity levels in under 500 years. About 95 percent of the radioactivity decays to background levels within 100 years or less.

Items that become low-level waste. Low-level waste includes such items as gloves and other personal protective clothing, glass and plastic laboratory supplies, machine parts and tools, filters, wiping rags, and medical syringes that have come in contact with radioactive materials. Low-level waste from nuclear plants typically includes water purification filters and resins, tools, protective clothing, plant hardware and wastes from reactor cooling-water cleanup systems.

More as news warrants.

UPDATE: Earlier today, NEI issued a one-page summary on the events in Japan. Text follows:

The Kashiwazaki-Kariwa nuclear power plant successfully withstood a major earthquake that struck northwestern Japan on July 16. The operating reactors shut down as designed. Some radioactivity was released as result of the event, but no public or environmental harm has resulted from the releases. The company still is investigating the full effects of the earthquake but has stated that there is no environmental or safety impact beyond the plant site.

Background
A strong earthquake that struck northwestern Japan on Monday affected operations at the seven-unit Kashiwazaki-Kariwa nuclear power plant. Four of the reactors shut down automatically, as designed (the other three were not operating at the time).

The earthquake caused approximately 300 gallons of water to spill from one reactor’s used fuel pool into an adjacent tank, from which it was then pumped to the sea. The water contained a small amount of radioactivity—about two microcuries, according to officials with Tokyo Electric Power Co. (TEPCO). The company stopped the release of the radioactive water, but not before it reached the Sea of Japan.

According to official reports, no “significant change” to the seawater has been detected near the plant. Jun Oshima, an executive at TEPCO, told the Associated Press that “the radioactivity is one-billionth the legal limit” of the water from the plant.

According to some reports, the earthquake also tipped over barrels containing low-level radioactive waste. A TEPCO spokesman said the company still was determining whether any barrels had leaked, but said it had found no effect outside of the plant.

The earthquake, estimated at 6.6-6.8 on the Richter scale, also caused a transformer fire at the facility that was quickly extinguished. The fire and the releases were not related.

Despite the considerable damage to the surrounding area, the Kashiwazaki-Kariwa nuclear plant performed as designed and withstood the effects of the earthquake. As a result, no environmental damage has resulted from the quake’s impact on the plant.

U.S. and Japanese nuclear plants are built with a “defense-in-depth” philosophy that uses multiple safety barriers and redundant, physically separated safety systems to ensure that public health and safety is assured even in severe circumstances like hurricanes and earthquakes.