Nuclear Plants and Nuclear Excuses: This is Getting Old

[kristopher]

Nuclear Plants and Nuclear Excuses: This is Getting Old

Dave Lochbaum, director, Nuclear Safety Project
February 25, 2014

Fission Stories #157

The NRC originally licenses a nuclear power reactor to operate for 40 years. The NRC renews an operating license for an additional 20 years. An operating license gives the owner the right to operate the reactor, provided a plethora of regulatory requirements are met. Many of these regulatory requirements seek to ensure safety margins are maintained throughout the full term of the operating license rather than just until next week or next month.

Getting old is but one of the reasons safety margins can decrease, or disappear, over time. The bathtub curve shown below shows that wear-out failures can cause the overall failure rate to increase. As a result, considerable resources and attention are devoted to monitoring the condition of nuclear plant components and replacing or repairing them as required before aging degradation compromises safety margins.



That, at least, is the theory.

Earlier this year, the NRC’s Operating Experience Branch released a report following its review of data from 2007 to 2011, inclusive. The NRC staff reviewed records such as findings by NRC inspectors and Licensee Event Reports (LERs) submitted by plant owners. Among the NRC’s key findings:

- “Since 2009, there is a notable increase in the number of inspection findings and LERs involving highly reliable components whose failure was attributed to age degradation after being in service for over 15 years.”

- “It is interesting to note that in more than 75 percent of the 105 datum that were reviewed, it was determined that the System, Structure, or Component (SSC) either exceeded its recommended service life or was effectively run-to-failure. Thus, it is reasonable to question the oversight effectiveness of the baseline inspection program in this area.”

- “About 40 percent of the 77 inspection findings were also Appendix B related findings, but only seven were cited against Criterion III, Design Control. Appendix B, Criterion III required licensees to verify or check the adequacy of design if safety-related equipment will remain in service beyond its qualified life. Thus, with greater than two-thirds of findings and events involving SSCs left in service well beyond expected service life, it is reasonable to question why NRC oversight programs are not more focused on aging management of active SSCs.”

- Bear in mind that NRC inspectors and plant owners don’t waste time and resources writing up age-related failures of lightbulbs in the warehouse and instead restrict their penmanship to failures of things that have a safety role to play in protecting workers and the public. Thus, the NRC’s report identified the inability of plant owners to prevent age-related failures coupled with the NRC’s inability to adequately enforce the regulatory requirements being violated.

That the NRC was inadequately enforcing regulatory requirements was documented in an audit report released on October 28, 2013, by the NRC’s Office of the Inspector General (OIG)...

http://allthingsnuclear.org/nuclear-plants-and-nuclear-excuses-this-is-getting-old/

Those bullet points bear repeating:

- “Since 2009, there is a notable increase in the number of inspection findings and LERs involving highly reliable components whose failure was attributed to age degradation after being in service for over 15 years.”

- “It is interesting to note that in more than 75 percent of the 105 datum that were reviewed, it was determined that the System, Structure, or Component (SSC) either exceeded its recommended service life or was effectively run-to-failure. Thus, it is reasonable to question the oversight effectiveness of the baseline inspection program in this area.”

- “About 40 percent of the 77 inspection findings were also Appendix B related findings, but only seven were cited against Criterion III, Design Control. Appendix B, Criterion III required licensees to verify or check the adequacy of design if safety-related equipment will remain in service beyond its qualified life. Thus, with greater than two-thirds of findings and events involving SSCs left in service well beyond expected service life, it is reasonable to question why NRC oversight programs are not more focused on aging management of active SSCs.”

- Bear in mind that NRC inspectors and plant owners don’t waste time and resources writing up age-related failures of lightbulbs in the warehouse and instead restrict their penmanship to failures of things that have a safety role to play in protecting workers and the public. Thus, the NRC’s report identified the inability of plant owners to prevent age-related failures coupled with the NRC’s inability to adequately enforce the regulatory requirements being violated.

[Systematic Chaos]

1. Indeed