Saturday, June 27, 2015


Status of PRM-50-93/95
Date: 6/23/2015 8:51:26 A.M. Mountain Daylight Time
Sent from the Internet (Details) 

Mr. Leyse,

I am writing to provide an update on your letters dated November 17, 2009, and June 7, 2010, in which you submitted petitions to the U.S. Nuclear Regulatory Commission (NRC).  In your letter dated November 17, 2009, you requested that the NRC amend the regulations in Title 10 of the Code of Federal Regulations (10 CFR) Part 50 and Appendix K to Part 50 to require that the rates of energy release, hydrogen generation, and cladding oxidation from the metal-water reaction considered in emergency core cooling system evaluation calculations be based on data from multi-rod (assembly) severe fuel damage experiments.  In addition, you requested that the NRC create a new regulation to establish a minimum allowable core reflood rate in the event of a loss-of-coolant accident (LOCA).  In your letter dated June 7, 2010, you requested that the NRC order Vermont Yankee Nuclear Power Station (Vermont Yankee) to lower the licensing basis peak cladding temperature to 1,832 degrees F in order to provide a necessary margin of safety in the event of a LOCA.

The NRC docketed your November 17, 2009, letter as petition for rulemaking (PRM) 50-93.  A notice of receipt and request for public comment on PRM-50-93 was published in the Federal Register on January 25, 2010 (75 FR 3876).  Your letter dated June 7, 2010, was submitted as a petition for enforcement action under 10 CFR 2.206.  On August 6, 2010, the NRC denied your § 2.206 petition because it did not demonstrate that Vermont Yankee was in violation of any NRC regulations.  Because your § 2.206 petition asserted that there were generic inadequacies in NRC regulations, the NRC decided to review it under 10 CFR 2.802 as a petition for rulemaking and docketed it as PRM-50-95.  Because PRM-50-93 and PRM-50-95 address similar issues, the NRC consolidated these two petitions for review as a single petition for rulemaking activity.  Another Federal Register notice was published on October 27, 2010 (75 FR 66007), and the comment period was reopened.  The public comment period ended on November 26, 2010.  Thirty-two public comments have been received to date on the combined petitions.  These comments have been posted at (ID:  NRC-2009-0554).

The NRC staff is considering the merits of your PRM and the public comments received.  As described in the NRC’s letter to you dated August 25, 2011, the NRC has decided to increase the visibility to the public of the NRC’s review of these particular petitions.  The NRC will publicly release its draft interim reviews regarding each group or category of issues on a periodic basis as the review progresses.  These draft interim reviews will be posted on  So far, the NRC has publicly released four draft interim reviews:

The NRC staff will consider and respond to the comments you made regarding PRM-50-93 and PRM-50-95 at the Commission briefing on public participation in NRC regulatory decision-making on January 31, 2013, in the review of these petitions.

The NRC is considering the remaining issues and will notify you as the draft interim reviews are completed.  Once the petitions have been resolved, a notice will be published in the Federal Register explaining the Commission’s finding.  You will also receive a letter at that time notifying you of the action that the Commission has taken.

Please feel free to contact me at or 301-415-3748 if you have questions.


Dan Doyle

Project Manager
U.S. Nuclear Regulatory Commission
(301) 415-3748

Friday, June 12, 2015

Explosive Potential of Zirconium Alloys with Dissolved Oxygen

And maybe hydrogen.

Impact on Chernobyl.

Or dry storage; Kewaunee welding.

Here are excerpts from recent press
regarding spent fuel rod proposed
work at Idaho National Laboratory

Here is a press release from a year ago:

Monday, June 8, 2015

On the Infiltration of Sand Hill Road

On the Infiltration of Sand Hill Road


Saturday, June 6, 2015

Nukiyama in Microscale at Higher Pressures

Nukiyama in Microscale; High Pressure:
Subcritical, Transcritical, Supercritical

This entry will take several days as slides are uploaded and paragraphs are written.   Indeed, this is Nukiyama in microscale.  Nukiyama made his discoveries via experiments.  About twenty years later, the mathematicians got in the game and since then the gang of "experts" insists that nothing is discovered in the absence of deep analysis.

Nevertheless, Leyse has produced and reported a set of transformative discoveries in the field of microscale heat transfer to subcooled water over a pressure range of 200 to 6000 PSIA.  These transformative discoveries are listed at the end of this collection of slides.

Nukiyama was the first to use a platinum
wire simultaneousllyas a heat transfer 
element and a resistance thermometer. 

Leyse thus pioneered application of the  
Nukiyama procedure in microscale.

The Nukiyama element is mounted 
within a pressure tube.  The quartz
tube is replaced with a stainless steel
tube for higher pressure runs.

 The assembly of the apparatus has
the pressure tube, the pneumatic
pressurizing pump, programmed power 
supply, PC with Microsoft EXCEL for
data logging and analysis, and a 
Rosemount pressure transducer.

Data is collected every 0.1 seconds.  
Heat flux is smoothly ramped up to
4100 W/cm2 in 5.5 seconds and then
ramped back down in 5.5 seconds.

 Above is the Nukiyama plot.

Here are several runs: three subcritical 
at 200, 1000 and 2500 PSIA, one 
transcritical at 3000 PSIA, and four 
supercritical at 3600 to 6000 PSIA.    


Here are the plots of the several runs
with the data points at increasing power.
Below are separate plots with details.

Here are two of the four supercritical runs,
3600 and 6000 PSIA.

This has the transcritical runs at 3000 PSIA 
along with the two supercritial runs.Note the 
onset of nucleate boiling very close to the 
critical temperature and the jump of about
480 Centigrade in 0.1 seconds across the
supercrtical region. In contrast, the return to
natural circulation takes one second.

These are the four supercritical runs and the 
transcritical run in decreasing power. It
will be revealing to conduct these runs at 
much faster recording rates; perhaps
every 0.001 seconds rather than 0.1 seconds.

At 3000 PSIA the saturation temperature is 
very nearly the critical temperature which 
likely accounts for the transformative 
characteristic. It is proposed to determine 
the pressure at which the transformative 
characteristic is initiated.  There are several
factors.  I prefer operating with cold water.
More later on this.

This has only the increasing power data for the
three subcritical runs at 200, 1000, and 2500 PSIA 
and the initial aspects of the transcritical runs at
3000 PSIA.  Nore that the onset of phase change 
is only a few degrees Centigrade above the 
saturation temperature at 2500 and 3000 PSIA, 
however, it is grossly above the saturation 
temperature at 200 and 1000 PSIA.

Professor Victor V. Yagov reviewed this work
and produced the above table of his analysis.
At 200 PSIA he reports substantial temperature
difference between the onset of phase change
and the saturation temperature.  At 3000 PSIA
that difference is very little.

With a 12.5 micron element, limited runs show
that performance is substantially the same as 
for 7.5 microns, although at lower heat fluxes.
At 1000 PSIA the onset of phase change is at
the same temperature in each case.  Likewise, 
the 2900 PSIA data at 12.5 microns mimics the
3000 PSIA data in all aspects, the onset of 
nucleate boiling, the jump across the supercritical
region, and the return to natural circulation. (Note 
that the saturation temperature at 2900 PSIA is
very close to that at 3000 PSIA; 366.1 and 368.9.)

This nested set of runs is fantastic, and it has
been in the public arena for over 15 years.  Again,
this is 7.5 micron data, and the runs were 
completed as an afterthought, a worthwhile 
afterthought.  The procedure is original and
straightforward.  The assembly is pressurized to
about 6000 PSIA,  full power is applied and 
substantially constant heat flux is maintained as
the pressure is smoothly reduced over a period 
of about twenty seconds.  Power is turned off at
about 200 PSIA.
Again, the discoveries are fantastic.  For run 
2630 W/cm2, the lowest heat flux, the plot is
smooth over the entire span.  It starts at 348  oC,
increases gradually until it crosses the critical 
pressure at 358   oC (about 16  oC less than the 
critical temperature), then increases very slightly 
to 360oC at 2700 PSIA where it is equal to the
saturation temperature.  At this point the heat 
transfer mechanism changes to nucleate boiling
and the temperature decreases significantly to
about 200 owhen the run ends at 250 PSIA.
During this nucleate boiling regime the difference 
between the temperature of  the 7.5 micron 
element and the saturation temperature increases
substantially as the pressure decreases from 
2700 to 250 PSIA.  This is consistent with the 
onset of phase change, slide 22, and the Yakov
analyses, slide 23.
Next, run 2930, an increase in heat flux of only
300 W/cm2 yields a remarkably change perfprmance
increasing temperatures,  240, 307 and 349 oC