[RayChuang88]

It's essentially detonating the old British Grand Slam bomb at surface level. I believe we have already built the components of the even more sophisticated GBU-57A/B Massive Ordnance Penetrator and could assemble such a bomb quickly to use against Kim Jong-un's underground bunkers. (Remember, underground bunkers are designed to withstand a near miss. With the GBU-57A/B, we talking a bomb with a CEP measured under 50 feet--and a deep earth penetrator with that accuracy will collapse most deep bunkers.)

[rxsid]

"I believe we have already built the components of the even more sophisticated GBU-57A/B Massive Ordnance Penetrator and could assemble such a bomb quickly to use against Kim Jong-un's underground bunkers. "

"GBU-57A/B Massive Ordnance Penetrator (MOP)
Each of the U.S. Air Force's B-2s is to be able to carry two 14-ton MOPs.[6][7]

The Air Force now has received delivery of 16 MOPs as of November 2011.[15] And as of March 2012, there is an "operational stockpile" at Whiteman Air Force Base.[16]"

More info: http://www.defenseindustrydaily.com/mopping-up-the-usas-30000-pound-bomb-03172/