New earthquake data
Since 1973, many more earthquakes have occurred around and even under Mt. Natib; one on June 24, 1991 with a magnitude of 4.6 occurred directly under Napot Point. Since 1981, six have occurred within 25 kilometers of the BNPP. Note that the largest nuclear complex in the world, the Kashiwazaki-Kariwa plant in Japan, was shut down by a magnitude 6.6 earthquake in July 2007 only 19 kilometers away. It is still inactive today.
The Lubao lineament
In 1997, Prof. Fernando Siringan, his students and I began to study land subsidence in coastal Bataan, Pampanga, Bulacan and Camanava. Very early, we noticed a sharp lineament in Lubao, Pampanga that trends southwest to Mt. Natib, where it abruptly disappears. Many earthquake epicenters plot along the lineament which, if extended farther, trends to Napot Point. The possibility that the lineament is a fault, and the possibility that it extends under Mt. Natib need urgently to be explored by scientists of Phivolcs and other institutions.
Professor Mahar Lagmay has established genetic relationships between faults and volcanoes, including Mt. Pinatubo and the volcanoes in Bicol.
Spent fuel pools
No country in the world has yet solved the problem of how to store nuclear waste permanently and safely for tens and hundreds of thousands of years. In the meantime, spent fuel is stored next to the plants, in pools of water that absorb the radiation and disperse the heat. The need for huge volumes of water to absorb excess heat from the reactor and from spent fuel is why the BNPP was built on the coast.
The US National Academy of Sciences has challenged the decision by federal regulators to allow this practice because of the risks of terrorist attacks. The US Nuclear Regulatory Commission is also very worried because loss of pool water could cause the zirconium alloy cladding of the most recently discharged spent fuel assemblies to combust spontaneously. The fire would then ignite adjacent fuel assemblies. Spraying the fire with water would make it worse because steam and zirconium react to produce even more heat.
Just like a fire in a reactor core, one in a spent fuel storage pool would release huge volumes of radioactive gases to the atmosphere, including much Cesium-137, which is water-soluble and extremely toxic, even in minute quantities.
Pool water could be lost in many ways such as pump valve or piping failures or a simple brownout. At Natib, an earthquake could simply slosh the water out of the pool. In an eruption, a pyroclastic flow could evaporate the water instantaneously.
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Kelvin Rodolfo is concurrently professor emeritus with the Department of Earth and Environmental Sciences, University of Illinois in Chicago, and an adjunct professor with the National Institute of Geological Sciences, University of the Philippines-Diliman. He is currently a DOST Balik Scientist. Discussion and corrections are welcome at krodolfo@uic.edu.