The article is really sparse on what information was missing. Neither the NRC or Oklo specified what else is needed. It’s probably wise to give both sides the benefit of the doubt.
“Oklo’s application continues to contain significant information gaps in its description of Aurora’s potential accidents as well as its classification of safety systems and components,” Veil said. “These gaps prevent further review activities. We are prepared to re-engage with Oklo if they
submit a revised application that provides the information we need for a thorough and timely review.”
(phew, that PDF does not copy/paste text cleanly, at least not in Safari. Had to re-type it.)
Asking for more information until the other party gives up is a tactic -- as is refusing to provide damning information. It's hard to say which game is being played, or even if any game is being played at all, without knowing details.
From Rod Adams: Oklo's COL application is part of an effort to achieve a difficult, but important goal. The company has challenged the standard way of doing things and designed a nuclear power system that is as different from a conventional reactor as a gasoline powered scooter is from a 100 MW slow speed diesel pushing a large container ship.
Oklo submitted a license application they believe satisfies the letter and the intent of the governing regulations in a form appropriate for its proposed system.
The NRC reviewers are not yet satisfied with the information provided and left open the opportunity to modify the application to fill in the gaps it believes exist.
The NRC chose to deny the application instead of continuing the process of obtaining additional information. That might have been stimulated by a legislative timeline of 3 years from docketing to final determination.
I expect Oklo will be resubmitting its application before the end of the summer.
Longer explanation
Oklo's application doesn't follow the Standard Review Plan format. That 4,500 page document of regulatory guidance fits the large light water reactor systems, structures, components, and processes it was designed for. But it is unwieldy and inappropriate for Oklo's reactor design. Reviewers are used to the SRP and the applications produced using its specified format; they are not yet comfortable with the way that the Oklo application provides required information.
The NRC's denial of Oklo's novel COL application is a disappointment, but it's not a complete surprise. Oklo is doing something that is difficult by pushing change in a federal regulatory agency whose processes and procedures have been developed over decades to focus on a particular kind of reactor.
Oklo's 1.5 MWe reactor uses liquid metal filled heat pipes to passively move heat energy out of a few dozen assemblies containing metallic alloy fuel rods.
That is a completely different machine than a 1,000 MWe reactor that pumps high pressure water through a core made up of hundreds of assemblies consisting of a bundle of hundreds of thin walled tubes filled with UO2 pellets.
Oklo and the NRC review team have worked diligently to come to an agreement that the COL contained information required for a complete safety review. Oklo has answered every request for information it has received, but the NRC has judged those responses to be not yet complete.
The NRC had the option of obtaining information it thought was missing through another, more focused round of RAIs and response. Under the pressure of a Congressionally mandated deadline of 3 years for reviewing a docketed application, it chose to deny the application "without prejudice."
This gives the NRC the opportunity, outside of a formal license review process, to communicate what they believe is missing from the application. It gives Oklo the opportunity to produce a better application that fills those information gaps.