zirconium oxidation and TRACE at Penn State

 Today I found this:

http://d-net.us/pdf/Nuc_E_431W.pdf

 

NucE431W S2013

Spent Fuel Pool Analysis of a BWR-4

Fuel Bundle Under Loss of Coolant

                          Conditions Using TRACE
 
                            For the period of January 7, 2013 through May 1, 2013


The Pennsylvania State UniversityDepartment of Mechanical and Nuclear Engineering
University Park, PA 16802
5/1/2013

ABSTRACT

The purpose of this project was to investigate the ability of TRACE to accurately model a single fuel bundle within a spent fuel pool and to determine the conditions for when a fuel bundle might initiate rapid oxidation of its zirconium cladding. Three models were developed and simulated using the TRACE thermal-hydraulics system code: a full height BWR bundle cooled by air, a partial height test composed of five BWR fuel bundles, and a full-height BWR bundle initially filled with water. The first two models represented experiments recently completed at the Sandia National Laboratory, while the third is a model of a planned experiment. Each model was used to estimate the time at which breakaway (rapid oxidation of the cladding) would begin, which is at approximately 1100 K based on experimental data. It was found from the full-scale air test that TRACE has the ability to approximately model a fuel bundle heat up within a spent fuel pool up to approximately 1073 K. The data prior to 1073 K has been determined to be an accurate representation with regards to the specified input parameters. It was found that fuel bundles will undergo ignition (the point in TRACE where the metal water reaction calculations begin and where the temperature increase jumps to several degrees per second – also known as the breakaway point) within eight hours for power levels above 4 kW for the full-scale water model. Additionally, it was found that there exists a clear direct relationship between the coolant flow rate and collapsed water height. More importantly, the TRACE results provided data indicating the ignition time as a function of bundle power.

EXECUTIVE SUMMERY   (Note by Leyse: The spelling is by Penn State.)
 
Initial tests conducted at the Sandia National Laboratory assumed that the worst case scenario for heat up of a fuel bundle in a spent fuel pool would be the case of complete fuel uncovery. Cooling of the bundle would occur by natural convection to air in this case, with flow entering through the bottom nozzle and exiting through the top of the bundle. This case, while a significant threat to the safety of the fuel bundles, may in fact not be the worst case scenario. The worst case scenario occurs when there exists only a small amount of water at the bottom of the fuel bundles which will cause a blockage in air flow through the bundle. This case would effectively reduce the heat transfer rates from the fuel causing the fuel to heat up at a higher rate than if natural circulation was occurring. Understanding the behavior of spent fuel bundles under beyond-design basis scenarios such as fuel bundle ignition has become important. In order to understand fuel bundle behavior in these situations, computer models and physical tests must be performed and benchmarked against one another before any one program can be considered reliable to produce accurate models.

In order to determine the modeling capabilities of TRACE two models were created and benchmarked against tests performed by Sandia National Laboratories. These models were the Full Length BWR-4 Full Bundle in Air, the 1x4 Partial Length BWR-4 Fuel Bundle Configuration in Air and the Full Length BWR-4 Fuel Bundle in Water. After determining the modeling capabilities with regards to the experimental data a third model, Full Length BWR-4 Fuel Bundle in Water, was generated based upon the original Full Length BWR-4 Full Bundle in Air model. This third model was generated in order to provide a starting point to develop a Full Scale Water ignition test at Sandia National Laboratory. The Full Scale Air test currently uses two “break” components within TRACE to create a pressure differential to drive the flow through the bundle whereas the actual test had a controlled forced flow which gives rise to some variations in the observed data from TRACE and that provided by Sandia National Laboratory.
 
Ultimately it was found that the bundle heat up and ignition behavior of the experiment conducted by Sandia National Laboratory is accurately modeled by TRACE. From here the water model was created by changing the working fluid from air to water and modifying the bottom “break” component in TRACE to a “fill” component to provide a controlled forced flow through the model. Varying bundle powers were examined in addition to three distinct flow rates. Relationships were generated for time to breakaway as a function of bundle power and collapsed water height as a function of flow rate. From these relationships it was found that increased powers reduce the time to breakaway and higher flow rates result in larger collapsed water heights for all examined cases which is to be expected. 

 

Basis for Venting Capacity

I have e-mailed the following to NRC today:

The following paragraph is from page 1 of  Basis for Venting Capacity in Order EA-13-109, “Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions” (ML13221A011):

Over the years a number of studies have been completed related to generation of energy within

the reactor core and subsequent decay heat once the reactor has shutdown. The American

Nuclear Society Standard (ANS) 5.1 (Reference 1) which was approved by the ANS standards

committee in August 1979 provides a method to calculate decay heat power in light water

reactors. In 1980’s, the NRC sponsored further studies under a program known as Severe

Accident Consequences Mitigation. In one of the reports, NUREG/CR-3908 (Reference 2),

Figure 2-1 provides decay heat rate and heat accumulation curve with time. It shows that after

3 hours, the decay heat is about 1 % (values shown in that figure were based on 3440 MWT

BWR plant at 80 % power, but they show power at or below the 1% of thermal power history

value at 3 hours). Generic Letter 89-16 (Reference 3) related to installation of hardened wetwell

vents was issued in September 1989 and stated that the system installed by Boston Edison

Company at the Pilgrim Nuclear Power Station and associated analysis was acceptable. The

design analysis included a vent design objective of venting approximately 1 % of decay heat for

a 56 psi saturated steam conditions in the torus. In July 1996, in Information Notice (IN) 96-39

(Reference 4), the NRC staff provided additional clarification in selecting input parameters for

estimating decay heat using methodology provided in ANS 5.1. The IN also included results

using various available computer codes (MELCOR, RELAP, TRAC, etc...). On the international

level, Swiss standard HSK-R-40/d (Reference 5) issued in March 1993 noted in Section 3.2 that

the design capacity should be based on a guiding value for steam production of 1% of the

thermal reactor power. References 6 and 7 provide additional information on decay heat

estimates and compares different methods and results.

The following sentence from the above paragraph is erroneous: “The design analysis included a vent design objective of venting approximately 1 % of decay heat for a 56 psi saturated steam conditions in the torus.”

The NRC should issue a corrected version of ML13221A011 that removes the above erroneous sentence.

That corrected version of ML13221A011 should clarify reference 3 by adding ML13017A234 or ML031140220 or both.  As it is now, the reference is incomplete.   3. Generic Letter 89-16, “Installation of a Hardened Wetwell Vent.” September 1, 1989.

In addition, that corrected version of ML13221A011, should replace the erroneous date on page 3 with the correct date.

Finally, the corrected version should acknowledge that the original version was produced in response to an e-mail inquiry by Robert H. Leyse, bobleyse@aol.com, to OPA.Resource@nrc.gov on 7/25/2013.  The corrected version should also acknowledge that the corrections were requested by Robert H. Leyse, bobleyse@aol.com,  via this e-mail dated 10/14/2013.

Robert H. Leyse   bobleyse@aol.com

Hardened Vent Links Pilgrim Boston Edison

The NRC PDR has e-mailed the following links.

http://pbadupws.nrc.gov/docs/ML1301/ML13017A234.pdf  

and

http://pbadupws.nrc.gov/docs/ML0311/ML031140220.pdf  

http://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber='ML031140220'

http://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber='ML13017A234'

Spent Fuel Fires Some links

Here are some links:

http://www.environmental-defense-institute.org
In this link, go to Publications and select Gordon Thompson Declaration to NRC on Spent Nuclear Fuel, 8-13. pdf


Here is another link:


www.gao.gov/assets/600/593745.pdf  or go to BING and enter GAO-12-797, below is the cover page.

SPENT NUCLEAR
FUEL
Accumulating
Quantities at
Commercial Reactors
Present Storage and
Other Challenges


Here is the link 
http://pbadupws.nrc.gov/docs/ML1322/ML13224A106.pdf 


Waste Confidence Generic
Environmental Impact
Statement
Draft Report for Comment

And here is the opportunity to comment which ends on November 27, 2013:
http://pbadupws.nrc.gov/docs/ML1325/ML13256A133.pdf
The NRC is also planning to hold ten public meetings around the country and two webcast
meetings nationally. Information about the meetings is available on the Waste Confidence Web
site at http://www.nrc.gov/waste/spent-fuel-storage/wcd.html.

Spent Fuel Pool Fires and Official Use Only (OUO)

Here is a useful reference: 

http://enformable.com/2011/09/7079/ 

The following chain of e-mails  is copied from the above link.  It is no wonder that I have not been provided with information regarding the Sandia work that I have requested.  

From: Gibson, Kathy
Sent: Wednesday, March 16,2011 2:17 PM
To: Zigh, Ghani
Subject: Re: Spent Fuel Experiments
We have multiple requests from multiple parties for a plethora of information. This request is in the que. Will talk with you about this when I can.
Thanks

From: Zigh, Ghani
To: Gibson, Kathy; Scott, Michael
Sent: Wed Mar 16 14:01:31 2011
Subject: FW: Spent Fuel Experiments
What is our decision on sharing the BWR zirc fire data with GE and NEI.
They are classified as OUO documents.

From: Durbin, Samuel [mailto:sdurbinsandia.gov]
Sent: Wednesday, March 16, 2011 1:57 PM
To: Zigh, Ghani
Subject: FW: Spent Fuel Experiments

From: Saito, Earl F. (GE Power & Water) [mailto:EarI.SaitoqCanf.com1
Sent: Wednesday, March 16, 2011 11:35 AM
To: Durbin, Samuel; Rochau, Gary; Lindgren, Eric; Gauntt, Randall 0
Cc: Bonano, Evaristo Jose; Sorenson, Ken B
Subject: RE: Spent Fuel Experiments
Thanks

From: Durbin, Samuel rmailto:sdurbin0sandia.gov1
Sent: Wednesday, March 16, 2011 1:20 PM
To: Rochau, Gary; Lindgren, Eric; Gauntt, Randall 0
Cc: Saito, Earl F. (GE Power & Water); Bonano, Evaristo Jose; Sorenson, Ken B
Subject: RE: Spent Fuel Experiments
Gary,
Attached are Mhe three relevant papers that were published in the ANS Transactions – Winter Meeting 2006 I Volume 95.
Your will note that the two papers based on the Sandia testing were heavily redacted at the instruction of the NRC. The test information is generally considered Official Use Only. We will need to receive permission from the NRC to release more substantial reports.
Sam
Samuel Durbin II
Sandia National Laboratories
Advanced Nuclear Fuel Cycle Technologies, Organization 6223
PO Box 5800 – MS 0747
Albuquerque, NM 87185-0747 •a
Office: (505) 284-7850A
Fax: (505) 844-2348

iau, Gary
esday, March 16, 2011 10:32 AM
, Samuel; Undgren, Eric; Gauntt, Randall 0
tito Ph. D. (earl.saitofte.om)’; Bonano, Evansto Jose
Spent Fuel Experiments
Sam, Eric, and Randy,
Earl Saito of GE-Hitachi has contacted me regarding some information on your Spent Fuel experiments, in particular, the BWR experiments. GE, as you can imagine, is trying to gather information on spent fuel pool issues for BWRs.
Can you please send the publically released papers you have written to “prime the pump”? I am sure there is material that you cannot share at this time, but I am looking at our NDA agreements to determine what latitude we may have, if any.
Gary E, Rochau, Manager
Advanced Nuclear Concepts
Nuclear Energy and Global Security Technologies Center
6585/2104, Organization 6771
P.O. Box 5800, MS-1136
Sandia National Laboratories
Albuquerque, New Mexico 87105-1136
Phone: (505)845-7543
Fax: (505)284-4276




 

Is NRC really that open? It is not.

Over a year ago, Borchardt of the NRC told my Senator Risch about NRC's openness and that I could get public information by directly contacting NRC staff instead of asking Senator Risch to get the facts.  It does not work that way, as readers may surmise from my entry of September 28, 2013.

Here is what Borchardt told Senator Risch: 

ADAMS, ML12059A117

March 1, 2012

The Honorable James E. Risch
United States Senator
1411 Falls Avenue E, Suite 2
Twin Falls, ID 83301

Dear Senator Risch:

On behalf of the U.S. Nuclear Regulatory Commission (NRC), I am responding to your letter of January 30, 2012, and a subsequent email from Kari Emond of your staff, both of whichforwarded correspondence from your constituent, Robert Leyse. Mr. Leyse raises additional issues on matters addressed in earlier correspondence with you or directly with the NRC in the  past. Responses to Mr. Leyse’s latest inquiries are enclosed.

The NRC has a long history of, and commitment to, transparency, participation, and collaboration in our regulatory activities. As discussed with your staff, we would like to clarify and re-emphasize that your constituent and other members of the public have ample opportunity to make comments on public rulemakings and obtain technical information from the NRC’s Public Document Room. In the past, Mr. Leyse has raised issues of technical interest and issues regarding availability of information. As a result, a number of documents have been made available at his request. Mr. Leyse can fully participate in the NRC’s activities through direct contact with the agency, as he has in recent years. For example, in 2002, he submitted a Petition for Rulemaking to which the NRC responded. All of the questions he submitted in his most recent correspondence can be accommodated in the normal manner in which the NRC does business.
 
In addition to public participation in our regulatory processes, we welcome the opportunity to respond to public concerns regarding safety or security. If he has any such concerns, Mr. Leyse can raise them directly to the NRC by contacting any NRC employee or by calling the NRC’s toll-free Safety Hotline at 1-800-695-7403. Calls to this number are answered 24 hours a day.
 
We appreciate you sharing this information with Mr. Leyse and urging him to contact the NRC directly in the future should he have additional questions.
 
Sincerely,
 
/RA/
R. W. Borchardt
Executive Director for Operations
Enclosure:
As stated 

Following is from my entry of September 18, 2013. 

Subject:	RE: Please assist (again)
Date:	10/1/2013 8:00:32 A.M. Mountain Daylight Time
From:	JLD_Public.Resource@nrc.gov
To: Bobleyse@aol.com

Thank you for contacting the NRC’s Japan Lessons-Learned Project Directorate. Your comments will be considered to the extent possible.

Japan Lessons Learned Project Directorate 

Office of Nuclear Reactor Regulation

Nuclear Regulatory Commission

So, I will have to again contact Senator Risch in order to get the data that I seek regarding hardened venting at the Pilgrim Nuclear Power Station.

Flocculation of zirconium

I wonder who (else) knows?