Washington (Platts)--18Jul2007

Japan's regulators are under pressure to order nuclear plant operators to
improve the ability of their facilities to withstand strong earthquakes after
a powerful temblor near a seven-reactor Tokyo Electric Power Co. facility
produced a peak ground acceleration twice that assumed in the plant's design
basis earthquake.

     Tepco cautioned that the readings from three seismograph stations at its
Kashiwazaki-Kariwa plant were preliminary, but confirmed expert reports that
they ranged from 311 to 680 Gal (centimeters per second squared). A European
expert said the design-basis PGA is about 250 Gal. The earthquake measured 6.6
on the Richter scale.

     A senior Japanese safety expert said the news ensured regulators would
keep all seven units down until their seismic design can be verified. The
8,200 MW station comprises half of Tepco's nuclear capacity.

     Regulators and Tepco agreed that the station's nuclear safety systems
responded as designed and safely shut the plant Monday, and that damage to the
plant was minor and was confined to storage areas, switchyards and non-safety
systems. A European seismic expert said the quake proved the plant was
designed with substantial safety margins.

     Tepco, however, is being criticized by top government officials for
failing to reveal the damage promptly enough, for taking 90 minutes to
extinguish a transformer fire and for initially reporting no radioactive
release. The utility later admitted that about a cubic meter of mildly
contaminated water was flushed to the sea.

     The damage that did occur means one focus of regulatory review will be on
whether the strictest seismic resistance requirements need to be extended to
parts of the plant, such as switchyards and service water systems that have
only been required to meet industrial seismic standards. Safety-related
nuclear systems have been subject to stricter standards in earthquake-prone
Japan. Those seismic review standards were just overhauled and tighter rules
issued in May.

	--Ann MacLachlan, ann_maclachlan@platts.com
	--Mark Hibbs, mark_hibbs@platts.com	
	--Margaret Ryan, Margaret_ryan@platts.com