Energy-Tech Magazine

Consequences
The net effect of all these uncertainties is high risk of delay. In fact, delays at TVO’s Olkiluoto 3 Finland plant appear to stem from these same problems:

• Licensing uncertainty forcing delays
• Change notices forcing rework from design changes due to licensing-required design changes originated by the regulator
• TVO/Areva accepting huge risks by moving forward with an unapproved design, attempting to salvage its project schedule. These problems allude back to U.S. nuclear plants in the 1980s: the NRC had to approve post-Three Mile Island (TMI) design changes. Not waiting for NRC approvals to continue work greatly increased the risk of rework for those mandatory design modifications. Deferring work was necessary for NRC approvals, but it put project schedules at risk. It was a no win situation; once Public Utility Commissions across the U.S. started to disallow nuclear project cost overruns for delayed plants, the lenders and shareholder had to eat those costs.

Numbers

Advertisement

of RAIs, changes and items to track
Several examples of process delays include:

• Lack of a specific final model for the licensed plant
• Lack of a set of certified qualified venders completely able to supply all the nuclear parts
• A regulatory framework that remains largely as it was in the 1970s - based on document reviews that result in manual update of the changes

To put that into perspective, in rough round numbers:

• Design Control Document (DCD): 10,000 text pages, of which 800 are tables
• Internal Cross References: 50 x 800 = 40,000 for the DCD alone
• External document cross-references from DCD: 10,000
• Average length: 100 pages
• External Documents
• Average number of cross references per document: 50
• External document cross-references 5,000
• Standards: 2,000
• Average number of cross references: 20
• Standards cross references: 2,000 x 20 = 40,000
• NRC Rules/Sections: 100
• NRC Regulatory Guides (Reg Guides): 100
• NRC Nuclear Regulatory Publications (Reg Guides): 100
• Average number of cross references: 20
• NRC cross references in rules, reference and Reg Guides: 20 x 300 = 6,000

Acceptance Criteria Specifications (“ITAACs”): 30,000 per plant

In summary, there are roughly 10,000 documents to track; the order of the number of document internal references to track is more than 100,000 for a single licensed plant design like the AP-1000!

Now consider that reviewing materials submitted by the licensee for one of these designs (Westinghouse, here) generates NRC reviewer comments that results in “requests for additional information” (RAI’s) to license applicant that must be resolved. The number of RAIs generated performing each certified design license review is roughly 5,000.

For each RAI there are several possible outcomes:

• No action taken (purely misunderstanding)
• Action taken but clarification comment (pure misunderstanding, but clarification added)
• Action taken that requires change in the substantial content text
• Action taken that requires change in the substantial content numerical calculation basis