Experts: Bataan site unsuitable for nuclear plant

BEFORE he goes any further in declaring his support for plans to activate the Bataan Nuclear Power Plant (BNPP), Secretary Mario Montejo of the Department of Science and Technology (DOST) would be well advised to confer with experts at his old alma mater, the University of the Philippines.

Certainly the DOST chief needs to consult Dr. Mahar Lagmay of the UP National Institute of Geological Sciences (NIGS)—and be ready to get an earful.

Lagmay and his team of geologists found that the BNPP site is not suitable for a nuclear power plant, a recent news article showed. Their conclusion arose from a study that the team conducted to detect and map out the geological hazards of a volcano—Natib—near the plant based on international guidelines set by the International Atomic Energy Agency (IAEA).

According to the article written by Anjo C. Alimario and posted on the website of the Makati-based daily BusinessMirror (http://businessmirror.com.ph/home/science/8801-site-not-suitable-for-bnpp-study-says), Lagmay’s 16-man team conducted the study on the geological hazards of southwest Natib, the site of the BNPP.

The authors of the study said considerable geological data have been collected to assess the geological hazards of Natib and serve as scientific basis for the evaluation of the BNPP’s activation as repeatedly proposed by certain lawmakers—and by the DOST chief himself.

According to the BusinessMirror article, Lagmay’s team began assessing the volcanic hazards at the BNPP site by identifying field deposits. At the southwest sector of Natib, the NIGS experts detected lahars—mudflow of volcanic debris—and lava flow fields and at least six pyroclastic density current (PDC) deposits with three of the PDC units directly underneath the site of the mothballed nuclear power plant.

“The PDC deposit, which is adobe in layman’s term, suggests that a volcano nearby erupted violently in the past,” Lagmay told Alimario.

Portions of the deposits are pinkish in color with flattened pumice, indicating that it was very hot when emplaced.

In addition, a previously unidentified eruptive center located 5.5 kilometers from the main building of the BNPP was mapped.

The NIGS study noted that the explosive pyroclastic deposits were identified as early as the late 1970s, collectively described as the Napot Point tephra, or solid material ejected explosively from a volcano such as ash, dust and boulders.

The NIGS team reported that deposits of lahars are widespread along the coastline of Napot Point where the BNPP is located. These deposits are found on top, below and in fault contact with other volcanic deposits.

Several lava flow ridges were also identified, including an eruptive center 5.5 km away from the BNPP site, the study reported.

According to IAEA guidelines, when evidence shows the existence of “capable” earthquake faults within one kilometer of a nuclear facility, another site must be considered. Such is the case for the BNPP where capable faults associated with the Lubao Fault were identified within one kilometer of the nuclear power plant.

The NIGS study noted that the BNPP was built in the late 1970s and early 1980s when safety of nuclear power-plant facilities were evaluated without the benefit of well-established, internationally accepted guidelines that set criteria and procedures for assessing potential volcanic hazards.

At that time, permits for constructing nuclear installations were granted based on investigations carried out according to local practices prevailing when the site was selected and were assessed based on science that preceded many aspects of volcanology that have rapidly developed only over the past 30 years.

According to the study, there is still a lack of adequate geologic maps of Natib Volcano until today, the same criticism given by IAEA experts, US geologists and oversight panels in the Philippines to the original hazard assessment, which gave rise to the decision to mothball the BNPP in 1986.

Without detailed geological maps that identify the stra-tigraphy—or the origin, composition and development of rock strata—and distribution of Natib’s eruptive products, the volcanic hazards at the site cannot be assessed properly, Lagmay reportedly said.

Considering the importance of the study area not only because it is the site of the controversial nuclear power plant but also because of its proximity to Pinatubo and Metro Manila, which is only about 70 km away, the study said, it is puzzling that almost 30 years after mothball-ing the BNPP and nearly 20 years after Pinatubo’s cataclysmic eruption, the level of understanding of Natib is still at its present state.

According to the report, a capable volcano or volcanic field is one that may experience volcanic activity during the performance period of the nuclear installation and, as discussed by the IAEA, such an event has the potential to produce phenomena that may affect the site of the nuclear installation. The concept of volcano capability was introduced to define the state of a volcanic system and as a means for evaluating its potential reactivation.

Natib is considered a capable volcano based on its active hydrothermal system with a magmatic signature. Thus, the impacts of volcanic hazards to the site were assessed based on the draft guidelines provided by the IAEA.

“Although the work on Natib Volcano is still in progress, enough data has been gathered, sufficient for use as one of the scientific bases for the decision of the Philippine government to recommission or not the mothballed Bataan nuclear facility and general hazards preparedness by communities on the slopes of the volcano,” the study said.

Alimario quoted Lagmay as saying that international guidelines set by international experts are not there to make exemptions for anyone. “We must remember that Japan and the Philippines have the same geological setting.”

Question: Is Montejo in contact with the scientific community or only with sections of it that echo his own personal views? –DAN MARIANO, Manila Times

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