 Ishibashi has subsequently claimed that, although the new guide brought in the most far-reaching changes since 1978, it was 'seriously flawed' because it underestimated the design basis earthquake ground motion.He has also claimed that the enforcement system is 'a shambles' and questioned the independence of the Nuclear Safety Commission after a senior Nuclear and Industrial Safety Agency official appeared to rule out a new review of the NSC's seismic design guide in 2007.Following publication of the new 2006 Seismic Guide, the Nuclear and Industrial Safety Agency, at the request of the Nuclear Safety Commission, required the design of all existing nuclear power plants to be re-evaluated.