March 17, 2014

NRC DISCUSSES POTENTIAL CHANGES TO BTP ON CONCENTRATION AVERAGING

By ExchangeMonitor

Nuclear Regulatory Commission staff yesterday gave stakeholders some insight into potential changes that will appear in the draft Branch Technical Position on Concentration Averaging that will be released for public comment in May. At the Waste Management conference in Phoenix, Jim Kennedy, lead on the BTP revision group for NRC, said that the agency is considering addressing conservatisms in its inadvertent intruder scenario, adding more examples of alternative approaches licensees could propose and eliminating language that could have resulted in unnecessary homogeneity testing. But, “We have a long-term review process, so whatever I say today is not cut in stone because we have a long process to go through to get the draft BTP out in the end of May,” Kennedy said.

NRC is willing to rethink some parts of its intruder scenario, which stakeholders and the Advisory Committee on Reactor Safeguards have criticized as being overly conservative. Kennedy said that was one of the primary comments staff will consider: “First that the scenarios are unnecessarily conservative, compounding the conservatisms. In choosing intruder scenarios, for example, we assume the probability is 1, it occurs immediately after the institutional control period ends after 100 years, and that it hits a hot spot,” he said. “I think all we’re going to say today is that we are revisiting scenarios in the next revision, particularly there’s been a lot of discussion about the intruder scenario and we are looking at that.”

The drilling scenario used for the inadvertent intruder analysis in the BTP is also getting a second look, Kennedy said. The intruder scenario, in particular the drilling method it assumed, came under fire from public stakeholders and the ACRS for being unrealistic. “We’re considering whether we’ll continue to rely on a scenario in which a small amount of waste is exhumed and spread along the surface,” Kennedy said. “We have some more information on that, and we’re considering whether to continue to rely on a scenario like that. All I can say at this point is that we’re considering it.”

Comments are closed.