Grundy Reporter

Dresden Nuclear Power Station, Unit 2 issued the following announcement on Sept. 11.

An Atomic Safety and Licensing Board has upheld a license amendment for the Seabrook

nuclear power plant’s operating license, but has imposed four additional conditions. The license

amendment addresses concrete degradation caused by the alkali-silica reaction. The Board

concluded the additional conditions to the license are necessary to provide adequate protection of

public health and safety.

In 2016, NextEra Seabrook, which operates the single-reactor Seabrook plant, located 13

miles south of Portsmouth, N.H., requested the amendment for analyzing the concrete degradation’s

impact on safety-significant areas of the plant.

The C-10 Research and Education Foundation filed 10 proposed contentions regarding the

amendment. The ASLB granted a hearing in October 2017 on five contentions, which it

consolidated into one contention – that NextEra’s large-scale concrete testing program yielded data

that are not representative of the reaction’s progression at Seabrook, and that the resulting

monitoring, acceptance criteria and inspection intervals are inadequate. The Board held a full

hearing on the matter in September 2019.

Given the decision’s use of proprietary information, the Board worked with the parties to

produce the redacted version now available. The Board concluded the amended license will meet

the NRC’s requirements when the agency’s Office of Nuclear Reactor Regulation imposes the

following conditions:

1) NextEra will monitor certain devices measuring concrete expansion every six months, rather

than starting in 2025 and every 10 years after that;

2) If stress analyses show degradation-related expansion and other forces will exceed the

strength of rebar in the concrete, NextEra must monitor the affected rebar to ensure it has not

yielded or failed, or detect such failure if it has already occurred;

3) If the degradation-related expansion rate in any area of a “seismic Category I” structure

significantly exceeds a certain limit, NextEra will evaluate whether to implement more

frequent monitoring; and

4) Each concrete core extracted from Seabrook must undergo a detailed microscopic evaluation

to detect degradation-related features.

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The ASLB is the NRC’s independent body charged with conducting adjudicatory hearings

and deciding legal challenges to the agency’s licensing and enforcement actions. The Board’s

decisions can be appealed to the five-member Commission heading the agency.

Original source can be found here.