arithmetic average, CEA, CEA drop time, CEDM, Control Element Assembly, Control Element Assembly drop time, Control Element Drive Mechanisms, Control Rods, Entergy, friction, Hiding information, Japan, Killona, Louisiana, mean, Mississippi River, New Orleans, NRC, nuclear energy, nuclear Katrina, nuclear power, nuclear safety, proprietary as excuse, public disclosure, public hearing, public safety, reactor pressure vessel head, RPVH, steam generator replacement, technical specifications, Toshiba, US, US NRC, Westinghouse
[How to intervene, and information about impacts, around mid-way in this post; search in page New Orleans.]
Entergy, which owns-operates Waterford Nuclear Power Station, asked the US NRC for an increase in CEA (Control Element Assembly) drop time, to match changes which have recently occurred at Waterford. In other words, they wish to change the technical specifications to match whatever’s wrong, rather than finding and fixing the problem (if it’s even fixable).
Entergy stated that they do not “expect” the condition to worsen, even though they are not quiet sure of the cause.
What is very strange, however, is that the NRC opted to give a longer drop time than Entergy was asking for in April (their official July request cannot be found, though)! Why? Did the NRC make a typo or what is being hidden?
Meanwhile, Westinghouse (owned by Toshiba) is hiding information from the public, which seems important, by calling it proprietary. Furthermore, Waterford’s new reactor pressure vessel head replacement seems to have been made by Westinghouse (Toshiba).
This slowing drop time can be a sign that something serious is amiss, which could lead to an inability for the control rods to work. It could be a sign of friction-misalignment which, it seems, might eventually make the control rods stick or break: “Mismanagement or control rod failure has often been the cause for nuclear accidents, including the SL-1 explosion and the Chernobyl disaster.“ https://en.wikipedia.org/wiki/Control_rod
“The NRC staff questioned whether any bowing of the CEA guide tubes had occurred, but the licensee stated that none was found….“(May 6 2015) http://pbadupws.nrc.gov/docs/ML1511/ML15117A503.pdf
Entergy, August 14, 2015, Attachment 1 to W3F1-2015-0061 Page 2 of 6 states that “All the apparent and possible causes are due to one-time plant modifications and therefore are not expected to further degrade. Since, no further degradation is expected, the action of raising the CEA drop time limit will resolve the lack of CEA drop time margin.”
http://pbadupws.nrc.gov/docs/ML1522/ML15226A346.pdf (emphasis added)
The current group average limit is 3000 milliseconds (3 seconds); Entergy Requested 3200 (3.2 sec); NRC proposal was for 3500 milliseconds (3.5 sec). For individual drop time current is 3200 (3.2 sec); Entergy wanted 3500 (3.5 sec) for individual drop times; NRC proposal has no limit for individual drop times and puts the average off of Entergy’s chart at 3500 for average. Why? Was this simply another NRC typo? Did Entergy change its request? Or, did Westinghouse request the change?
Historical Drop Times CEA drop time group arithmetic average
CEA DROP TIME T S CHANGE REQUEST CEA DROP TIME T.S. CHANGE REQUEST WATERFORD 3 APRIL 22, 2015 (Additional comments added)
In May: “The licensee discussed potential causes of the increase in the CEA drop times. The licensee cited the steam generator replacement, vessel head replacement, CEA replacement, and transition to the Next Generation Fuel Product could all be contributing factors, but no exact cause had been determined. The NRC staff questioned whether any bowing of the CEA guide tubes had occurred, but the licensee stated that none was found. The licensee stated that no mechanical problems are suspected as a factor in the increased drop times. The NRC staff requested that information on CEA drop time distribution be included in the submittal to determine if the CEA drop time step change increase also affected the CEA drop time distribution.” (p. 2) (May 6, 2015 letter to NRC)
http://pbadupws.nrc.gov/docs/ML1511/ML15117A503.pdf (Emphasis added)
In August: “The apparent cause of the rise in CEA drop times is the combined effects of major plant modifications that increased the resistance experienced by the CEAs during the insertion from 100% withdrawn to 90% inserted. The first possible cause could be due to a change in Control Element Drive Mechanisms (CEDM) voltage decay time between the original and replacement CEDMs causing a delay in the start of the CEA drop. A second possible cause could be due to the change in as-built manufacturing tolerances in the replacement reactor pressure vessel head (RPVH) resulting in increased friction between the CEA extension shaft and the RPVH and thus slower CEA motion.
The apparent cause and second possible cause are bounded by the change to the CEA drop time and analysis provided in Waterford 3 letter W3F1-2015-0040 [Reference 5.3].”
“It is a reasonable expectation that the Table 3.0-1 average CEA drop time at 90% insertion (3.2 seconds) will bound the test data based upon past surveillances.“The above is from W3F1-2015-0061, Entergy Letter to NRC dated August 14, 2015 http://pbadupws.nrc.gov/docs/ML1522/ML15226A346.pdf (Emphasis added)
Entergy appears to still be saying that 3.2 seconds, 3200 milliseconds is enough for the average CEA drop time, yet the NRC is giving them 3.5 seconds, 3500 milliseconds. There is also some margin of error.
ML15197A106 Letter from July cannot be found and yet Entergy references it: “the CEA drop time and analysis provided in Waterford 3 letter W3F1-2015-0040 [Reference 5.3] W3F1-2015-0040, License Amendment Request to Revise Control Element Drop Times, July 2, 2015 [ADAMS Accession Number ML15197A106]“. “On July 2, 2015, Entergy Operations, Inc. (Entergy) requested an amendment to revise the Control Element Assembly (CEA) drop times associated with Technical Specification 220.127.116.11 for Waterford Steam Electric Station Unit 3 (Waterford 3) [Reference 1].” W3FI1-2015-0062. September 23, 2015 http://pbadupws.nrc.gov/docs/ML1526/ML15268A019.pdf
[The rest of today’s blog post was written before it was suddenly noticed that what the NRC was proposing did not match the Entergy request.]
How is the following “figure” supposed to help anyone understand an already complex topic? Or experts to evaluate? Why is alleged Japanese corporate interest (Toshiba owned Westinghouse) more important than public safety?
The above is the last page of the second document (ML15268A020) in the “Packet” for “Waterford, Unit 3 – Control Element Assembly Drop Times Submittal Request for Additional Information” [by USNRC]. Packet Accession Number: ML15268A013 http://pbadupws.nrc.gov/docs/ML1526/ML15268A013.html
This is from the first document (ML15268A019) in the “packet”:
Attachment 2 to W3F1 -2015-0062 ML15268A019
http://pbadupws.nrc.gov/docs/ML1526/ML15268A019.pdf This information was posted only 10 days before the online comment deadline. The delayed posting and content is reason enough to request a public hearing. (See more below)
Whether you love or hate New Orleans; love-hate New Orleans
or don’t even know or care where it’s at, a nuclear accident at Waterford Nuclear Reactor near New Orleans has the potential of seriously impacting most of North America, and shutting down a large part of the US economy, by shutting down the lower Mississippi River and some of its most important ports. New Orleans would be un-evacuable in the event of a nuclear disaster. There are warnings for hurricanes. The only warning for nuclear accidents is that most reactors are old and safety standards are being constantly reduced, with NRC approval. The NRC remedy for imminent nuclear disaster seems to be their apparent current attempt to increase radiation exposure to the general public 100 fold. Radiation 15 times higher than that allowed in Japan is already allowed in US food -allowed by USFDA-, using the excuse of not wanting to slow down world trade.
If you are among the almost 2 million within 50 miles of Waterford Nuclear power station, even the US NRC will allow “standing” to protest within 60 days, with a request for public hearing-petition to intervene. To see how close you are to this and other US nuclear reactors, go here: http://www.psr.org/resources/evacuation-zone-nuclear-reactors.html There can be deaths, within the first weeks, as far as 60 miles away from a nuclear accident! See: “Chernobyl on the Hudson“: http://www.ucsusa.org/sites/default/files/legacy/assets/documents/nuclear_power/indianpointhealthstudy.pdf
“The 2010 U.S. population within 10 miles (16 km) of Waterford was 75,538, an increase of 7.4 percent in a decade, according to an analysis of U.S. Census data for msnbc. com. The 2010 U.S. population within 50 miles (80 km) was 1,969,431, a decrease of 0.8 percent since 2000. Cities within 50 miles include New Orleans (33 miles to city center).”
People had warning for Hurricane Katrina, but many lacked the means to get out.
Wind Roses can give an idea of where radiation will fall in the event of an accident – hopefully on Washington DC while NRC workers are outside. Wind rose plots: http://www.wcc.nrcs.usda.gov/ftpref/downloads/climate/windrose http://www.wcc.nrcs.usda.gov/climate/windrose.html Because of wind and rain, the Chernobyl Nuclear Accident had, and continues to have, serious impacts well over 1,000 miles away, in the UK and Scandinavia.
“§ 2.309 Hearing requests, petitions to intervene, requirements for standing, and contentions“.
Unfortunately, we only saw this a few hours before the online comment deadline. Nonetheless, there is until November 9th to petition to intervene. While the online comment deadline was October 8th, important information was not even released until September 28th, and some is still being withheld using the excuse of proprietary information. Certainly “Safety Analysis” sounds important for the public to access-understand “: The proprietary information sought to be withheld in this submittal is that which is appropriately marked in CE-15-284-P, Revision 1, Attachment 2, “Fuel Management Adjustment to [Radial Fall-off] ac to Reserve Margin for Thermal Conductivity Degradation” (Proprietary), for submittal to the Commission, being transmitted by Entergy Operations, Inc. letter and Application for Withholding Proprietary Information from Public Disclosure, to the Document Control Desk. The proprietary information as submitted by Westinghouse is that associated with Fuel Performance, Safety Analysis and the associated Thermal Conductivity Degradation methodologies, and may be used only for that purpose.” “Attachment 2 to W3F1 -2015-0062” Page 5 of 7 in
Attachment 2 to W3F1 -2015-0062 ML15268A019
It is difficult to even find a clear definition of a CEA. According to World Nuclear News, the Control Element Assembly (CEA) is “a cluster of control rods which are moved by a single drive mechanism.” (See “Westinghouse and KNF launch joint venture” 06 February 2009). This is the only clear definition easily found online. So, this operating change has to do with slowing down the insertion speed of control rods for Waterford Nuclear Reactor. Control Rods do just that – they control the nuclear reactors.
“Mismanagement or control rod failure has often been the cause for nuclear accidents, including the SL-1 explosion and the Chernobyl disaster.“
It is important to notice that they are using arithmetic average (mean), and there is no individual maximum discussed, as there was in Entergy’s original proposal. This means the numbers can be all over the place, as long as they average less than 3.5 seconds. This is unacceptable. The original rules and original request give a maximum for individual CEA drop times. “SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is considering issuance of an amendment to Facility Operating License No. NPF–038, issued to Entergy Operations, Inc. (the licensee), for operation of the Waterford Steam Electric Station, Unit 3. The proposed amendment will modify Technical Specification (TS) 18.104.22.168, ‘‘Control Element Assembly [CEA] Drop Time,” and the Final Safety Analysis Report (FSAR), Chapter 15, “Accident Analyses.” Specifically, the amendment would change TS 22.214.171.124 to revise the arithmetic average of all CEA drop times to be less than or equal to 3.5 seconds.” “DATES: Submit comments by October 8, 2015. Requests for a hearing or petition for leave to intervene must be filed by November 9, 2015“. http://www.regulations.gov/contentStreamer?documentId=NRC-2015-0205-0001&disposition=attachment&contentType=pdf
The presentation in April gave Individual CEA drop times ≤ 3.2 seconds to be raised to ≤ 3.5 seconds, and average CEA drop times to be increased from ≤ 3.0 seconds to ≤ 3.2 seconds
“Background for LAR [License Amendment Request]
• CEA Drop Times have challenged the Technical Specification (TS) limit in the last two surveillance performances limit in the last two surveillance performances
– Waterford 3 TS 126.96.36.199 requires:
• the arithmetic average of all CEA Drop Times be ≤ 3.0 seconds
• Individual CEA drop times ≤ 3.2 seconds
• Insertion time is measured from fully withdrawn position to 90% inserted,” (p.4)
WHY ARE THEY HAVING TROUBLE FOLLOWING THE RULE ON THE CEA DROP TIME? THEY DON’T KNOW!
IT MIGHT BE:
Plant Primary Side Modifications
• Steam Generator replacement
• Reactor Vessel Head replacement
• CEA replacement
• Transition to Next Generation Fuel Product“, (p.6)
INSTEAD OF SOLVING THE PROBLEM THEY WANT TO CHANGE THE RULES-STANDARDS
“Proposed TS Change
• Waterford 3 TS 188.8.131.52 would be revised to:
– Raise the arithmetic average of all CEA Drop Times to be ≤ 3.2 seconds
– Raise the Individual CEA drop times to ≤ 3.5 seconds” (p.7) From: “CEA DROP TIME T S CHANGE REQUEST CEA DROP TIME T.S. CHANGE REQUEST WATERFORD 3 APRIL 22, 2015
While the above gives an individual CEA upper bound, the actual Docket ID NRC-2015-0205 states only:
“The proposed amendment would change TS 184.108.40.206 to revise the arithmetic average of all CEA drop times to be less than or equal to 3.5 seconds.” https://www.federalregister.gov/articles/2015/09/08/2015-22553/entergy-operations-inc-waterford-steam-electric-station-unit-3
Twenty-four (24) years ago at another nuclear reactor: “The proposed amendment increases the maximum allowable control rod drop time from 2.2 to 2.7 seconds. This increase is anticipated to bound any increase in drop time resulting from the planned use of the Westinghouse VANTAGE-5H fuel for the next refueling of Wolf Creek. The VANTAGE-5H fuel design incorporates a control rod guide thimble diameter slightly smaller, i.e., 0.442 inch in diameter than the 0.450 inch currently used. The slightly smaller diameter will increase the hydraulic resistance which will result in an increased rod drop time.” http://pbadupws.nrc.gov/docs/ML0220/ML022030229.pdf
Based on the above, one suspects that Waterford has already increased its drop time.
Furthermore, there is uncertainty-error:
“…the CDTT software having a CEA drop time uncertainty of 100 milliseconds (0.1 seconds).” (p.4)
NRC also states: “…which would have a negligible change on the radiological consequences.” ( p. 13) This is NRC-speak. Note that there would be little change in the radiological consequences of an accident – but how about the risks of the accident!? This is the sort of confusing crap that they always put. Beware!
What is CEA and Why is it Important?
“The reactor is controlled by a combination of chemical shim and a solid absorber. The solid absorber is boron carbide in the form of pellets contained in Inconel tubes. Five (5) tubes of absorber form a CEA (four tubes in a square matrix plus a central tube). The five (5) tubes are connected together at the tops by a yoke which is, in turn, connected to the control element drive mechanism (CEDM) extension shaft. Each CEA is aligned with, and is inserted into, a guide tube in the fuel assembly. Chemical shim control is provided by boric acid dissolved in the coolant (water). The concentration of boric acid is maintained and controlled as required by the chemical and volume control system (CVCS)… Reactor parameters are maintained within acceptable limits by the inherent self-controlling characteristics of the reactor, by CEA positioning, by boron content of the reactor coolant and by operating procedures…” “UNITED STATES NUCLEAR REGULATORY COMMISSIONTECHNICAL TRAINING CENTER COMBUSTION ENGINEERING TECHNOLOGY CROSS TRAINING COURSE SYSTEMS MANUAL” http://pbadupws.nrc.gov/docs/ML0228/ML022840127.pdf
Drop time should be less than or equal to 3 seconds: http://pbadupws.nrc.gov/docs/ML0228/ML022840127.pdf
The following are a few excerpts from: “Attachment I to W3FI1-2015-0062, Response to NRC Request for Additional Information“:
“The increased CEA drop time impacts the power reduction post-trip and the amount of energy deposited into the primary coolant system. The slightly longer drop time means a slight increase in the amount of energy added to the system. The assessment provided in W3FI-2015-0040 used the loss of condenser vacuum event because it produced the largest post-trip primary and secondary pressure spike due to losing its secondary heat removal capability.” (p.9)
“After reactor trip are insignificant. As time increases farther past the time of CEA rod insertion, the differences of the impact of the revised CEA drop time become negligible. The radiological releases due to steam release and break flow would remain the same. In addition, the W3FI-2015-0040 Attachment 2 results for each of the individual events demonstrate that the fuel failure limits remain unchanged which mean the radiological source terms remain the same. The W3F1-2015-0040 conclusion was there is no change to the radiological results.” (p. 12) [Note no change in the radiological results of an accident. How about risk of an accident?]
“The increased CEA drop time impacts the power reduction post-trip and the amount of energy deposited into the primary coolant system. The slightly longer drop time means a slight increase in the amount of energy added to the system. For the loss of normal feedwater event, Figure 15-1 shows the energy added to the reactor coolant system from time of trip (43.7 seconds) to 50 seconds for both the AOR and revised CEA drop time…” ( p. 12)
“The affected SG [Steam Generator] blowdown duration is dominated by the SG water inventory, initial temperatures, and break size. The increased CEA drop time impacts the power reduction post-trip and the amount of energy deposited into the primary coolant system. The slightly longer drop time means a slight increase in the amount of energy added to the system. The slight increase in energy would have a minimal impact on the SG pressure and no change to the event characteristics.” (p.17) [Note no change in event characteristics. How about event occurrence?]
“The increased CEA drop time impacts the power reduction post-trip and the amount of energy deposited into the primary coolant system. The slightly longer drop time means a slight increase in the amount of energy added to the system. The assessment provided in W3F1-2015-0040 used the loss of condenser vacuum event because it produced the largest post-trip primary and secondary pressure spike due to losing its secondary heat removal capability. Since, loss of condenser vacuum event produces a more adverse pressure transient, the slight energy deposition increase would be expected to have the most adverse impact on this event. Thus, the loss of condenser vacuum event results would continue to bound the CEA withdrawal event pressure transients.” ( p. 19) http://pbadupws.nrc.gov/docs/ML1526/ML15268A019.pdf
Information not released until Sept. 28th: http://pbadupws.nrc.gov/docs/ML1526/ML15268A013.html
Aging Management Plan for Waterford: http://pbadupws.nrc.gov/docs/ML1526/ML15267A797.pdf
List of problems at Waterford, including issues with emergency backup generator; lights; and missile problems, which are especially important due to hurricane and tornado risks: http://www.nrc.gov/NRR/OVERSIGHT/ASSESS/WAT3/wat3_pim.html
Drop time is supposed to be less than or equal to 3 seconds:
Appendix has info alleging Westinghouse proprietary info being hidden: http://pbadupws.nrc.gov/docs/ML1526/ML15268A019.pdf
“Attachment 3 to W3F1 -2015-0062, most info blank“: http://pbadupws.nrc.gov/docs/ML1526/ML15268A019.pdf
“US NRC: COMBUSTION ENGINEERING TECHNOLOGY CROSS TRAINING COURSE, SYSTEMS MANUAL” http://pbadupws.nrc.gov/docs/ML1330/ML13303A892.pdf
San Onofre, 1982 request to change CEA Drop time:
EPRI Manual on Pressurized Reactors: http://pbadupws.nrc.gov/docs/ML0901/ML090160205.pdf
Problem with insertion of CEA