the nrc resisted all that and mandated those fixes be made. flood barriers were put in, watertight doors were installed. ft. calhoun was a stellar example of the nuclear regulatory commission taking proactive action to protect people living in nebraska. >> o'brien: so just to be clear, had the nrc not intervened as they had in advance of that flood, what would have happened there? >> the flooding at ft. calhoun may not have triggered a meltdown, but it would have severely eroded the defense in depth. many of the barriers, many of the pumps would have been under water and unavailable. >> o'brien: nuclear engineer dave lochbaum, who monitors the u.s. nuclear fleet for the union of concerned scientists, says the nrc hasn't always been so proactive. >> the biggest concern i've had with the nrc over the years i've been monitoring them is lack of consistency. they're a little bit slow at solving known safety problems. >> o'brien: like earthquakes. take the case of the north anna plant in virginia. these two reactors were among 27 around the country

we have an application pending with the nrc. >> reporter: with all this radioactive material on site, sykes' work raises an important question: if a powerful earthquake triggered a series of unforeseen events leading to a release of radiation like fukushima, how would so many people make their way to safety? >> ifill: nuclear aftershocks can be seen on >> ifill: "nuclear aftershocks" can be seen on pbs' frontline tonight. check your local listings for times. >> woodruff: next, the battle over online piracy is heating up as companies are taking their case directly to web users. ray suarez has the story. >> suarez: if you normally turn to wikipedia to look things up, you'll have to go elsewhere tomorrow. the english version of wikipedia along with other popular sit such as read-it and boing boing will go black for 24 hours to protest anti-piracy legislation. the company has opposed two federal bills to stop on-line piracy act known sass op-a and the protect i.p.act. the legislation could force websites to monitor material from users that may include copyrighted content. it could also gi

the nrc to package it will be the seventh time that these two teams will have met.ams are rolling costs towards sunday and are starting both quarterbacks. alex smith has thrown 201 passes without an interception. our offense is heating up. on the other side of the field, new-line manning has thrown three touchdown passes in three games. >>mark: 2600 tickets available right now on stubhub for. if prices go from $8,500 for lower box seats all the way down to about $325. >>darya: we will keep our eyes on the candlestick park area, the game, parking, tickets and everything you need to know about the championship on sunday. these playoffs will determine if we go to the super bowl. we will be right back. >>darya: the visibility is pretty good. i am wondering if we will see any sunshine before the rain moves in. >>james: we will stay mostly cloudy all morning long. into this evening, some pretty severe rain. here is what we can expect in terms of total accumulation. by 11:00 p.m. almost 2 in. of rain, a little more than an inch in nevada. same-store for san mateo. a little

a number of the prc and nrc spies that took place and talks about what i just talked about. there's 14 very high profile roc spies for the prc. if you look at these individuals, look at their ranks, and look where they were. you know, retired colonel. you have a petty officer. you have a retired colonel for the military intelligence branch. then you have one civilian high-tech organization, and then their fbi. the mib, you have in essence every organization of their intelligence services penetrated leading up to a big case this year. it was almost like a kris -- cresendo leading up to the case. one was a couple looking for information after retirement, and he was arrested in 2002. they recruited their son as a decoder for the navy and used him also. this was a family affair, if you would, and they took photographs of ports and vessels, examples of naval operation systems and so forth. they used their information to e-mail them. the son passed it to dad, passed it to the prc. the navy petty officer, when he was arrested for espionage in 2002, he got a life sentence. the dad r