Saturday, May 26, 2012

At last, NUREG/CR-6980

I've been after this for several years.  Finally, here it is: RBHT Reflood Heat Transfer Experiments Data and Analysis

Document A
http://www.nrc.gov/site-help/search.cfm?q=ML12128A368


The Report, NUREG/CR-6980, covers the period Nov 1997- Feb 2003, but it was not published until April 2012!  It is a somewhat useless report, and I was aware of that likelihood well before the NRC released it.

In the FORWARD to the report, page 7 of 599, we read, "With improved data and code models for an LBLOCA, we can more accurately predict the consequences of LBLOCA accidents and provide better technical bases for regulations associated with such accidents.  As a result, this study will help to achieve the NRC's strategic performance  goals of making the agency's regulations more efficient, effective, and realistic."

It has been no secret that the NRC's Rod Bundle Heat Transfer (RBHT) at Penn State is essentially useless for modelling an LBLOCA because the test section includes no zirconium alloy structures, especially the fuel rod simulators which have inconel cladding.  The RBHT has been operated with cladding temperatures less than 1800 degrees Fahrenheit, well below the NRC's Appendix K limit of 2200 degrees Fahrenheit. 

Aside from the fundamental defects in the design of the RBHT and the very limited scope of its test program (the low temperatures of the tests and the absence of zirconium alloy structures), the report NUREG/CR-6980 does not include any discussion of the test results.  For example, in one run, there were very large temperature oscillations.  I have sent the following e-mail to the lead investigator at Penn State's Applied Research Laboratory. 

It is unfortunate that the report does not discuss this temperature cycling.  The data is about 10 years old and Professor Hochreiter, the originator of RBHT is no longer available to discuss this.  If NRC had not withheld the data for about 10 years, there would perhaps have been meaningful responses to significant  inquiries.  As matters stand, there is very likely no motivation on the part of the investigators to return to this old data.

There is more to this situation, and I will add to this.  On MAYDAY 2002, I submitted a Petition for Rulemaking to the NRC and on May 8, 2002, it was docketed as PRM-50-76.

Document B

Right now I'll jump ahead to the NRC review of my PRM-50-76 because it relates to NUREG/CR-6980.  The document is "TECHNICAL SAFETY ANALYSIS OF PRM-50-76."  It is a rather lengthy document and it castigates PRM-50-76.

Document C 
http://pbadupws.nrc.gov/docs/ML0412/ML041210109.pdf

On page 10 of 18 of this so-called technical analysis , it is asserted that the expense of PRM-50-76 would have only "marginal benefit" in comparison with the activities at Pennsylvania State University and elsewhere. "This would be a minimum requirement before considering the expense of high temperature Zircaloy tests, which would have marginal benefit in terms of increased understanding of LBLOCA heat transfer and metal-water reaction kinetics.  Current programs at Pennselvania State University (PSU)and Argonne National Laboratory (ANL) and elsewhere are far more cost effective."  (Please note that the spelling of Pennsylvania is the NRC's.)

For the moment, let's reflect on the timing of the documents.  PRM 50-76 was docketed on May 8, 2002.  The NRC's Technical Analysis of PRM-50-76 is dated April 29, 2004. Although NUREG/CR-6980 is dated April 2012, it covers the Penn State activities from November 1997 - February 2003.  The point is that the NRC should have been aware that the program at Pennsylvania State University was totally outside of the realm of the Zircaloy bundle tests that are called for in PRM-50-76.

At this point the reader is asked to return to page 10 0f 18  of Document C. (Update later)

And here is a Risch document.

Dopcument D

http://pbadupws.nrc.gov/docs/ml1206/ml12060A144.pdf

Document E  Leyse e-mail to chairman (PM-50-76)

http://pbadupws.nrc.gov/docs/ML1005/ML100500035.pdf

Document F  SECY-05-0113  20 pages

http://www.nrc.gov/reading-rm/doc-collections/commission/cvr/2005/2005-0113vtr.pdf

Document G  SECY-05-0113  32 pages

http://pbadupws.nrc.gov/docs/ML0502/ML050250359.pdf







No comments: