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  1. rcchap

    SR Valve Diffusor?

    Yes, the valve manufacturer will have an Appendix B QA program that will allow them to dedicate sub-supplier parts as safety related, even if the sub-supplier does not have an Appendix B program. This is fairly common. Obviously your utility has audited the valve manufacturer QA program and...
  2. rcchap

    Reducing Time stroking for Air Operated Valve - Positioner, Booster

    Does your valve need to be full open in 10 seconds, or does it need to be throttled to the required flow in 10 seconds? What system is this on and what is the required flow? I don't know if it helps, but we had a Copes Vulcan control valve on the discharge of our Aux Feedwater pumps (3" line...
  3. rcchap

    ASME Section III, Class 3 Valve W/ "N" Stamp

    There is one other thing you need to be aware of. Specific requirements might have been originally specified for the valves used during construction of your plant (such as additional NDE or specific seismic accelerations). For a 2" valve, you probably have a small bore valve spec that was...
  4. rcchap

    hindsight- how to avoid repeat of Fukushima

    Dry cask storage is not necessarily the solution. Current dry casks technologies are not designed for permanent storage, nor are the designed for travel. The dry cask storage is at the plant site, so the fuel is moved only a very short distance. Usually the trucks that do this moving go very...
  5. rcchap

    Japanese nuclear accident FAQ

    owg: The "normal" cooling circuit with the circ water system would not be used without offsite power available. The circ water pumps are very large and require a large amount of power. These pumps would not be able to be supplied from the emergency diesel generators. The EDGs would only feed...
  6. rcchap

    Japanese nuclear accident FAQ

    Just to clarify a couple of points: - zuesfaber is right. In the diagram above, the condenser shown in only used when they are making electricity. The turbines, condenser, and the circulating water system is not used if offsite power is lost. They would likely have another seawater cooling...
  7. rcchap

    Putting Radiation Dose in Perspective

    Attached is a very informative comparison of radiation doses from many sources.http://files.engineering.com/getfile.aspx?folder=1e9fe613-15ce-4fe0-a95b-e5c98e4941c6&file=Radiation_Chart.pdf
  8. rcchap

    Japanese nuclear accident FAQ

    printing724: I agree completely. A long term SBO is no longer beyond design basis. This will our affect our entire industry. Your XC system sounds unique to a sub plant. Land based PWRs (at least the ones I have worked at) don't have that. It makes sense to have this on a sub. Trottiey...
  9. rcchap

    hindsight- how to avoid repeat of Fukushima

    What you have found is a simulation program. This seems to be a simple one. Most (if not all) US reactors will have a full scale simulator room that mimics the actual control room and is controlled by computers that are programmed to mimic plant operation. These are used for operator training...
  10. rcchap

    Air Header Flow drops to zero when compressor unloads

    That sounds like a possible explanation. But I can't get around the fact that the receiver tank (which is upstream of this flow indicator) is depressurizing from 110 psig to 104 psig in 15 seconds, and as this tank depressurizes there is about 200 SCFM of air flowing in the direction of the...
  11. rcchap

    hindsight- how to avoid repeat of Fukushima

    davefitz: We can agree to disagree I guess. I know that there are advanced digital technologies out there, but they are rarely used in the nuclear industry, and would definitely not be used for reactor control. We keep it simple and analog. A networked control room will never happen because...
  12. rcchap

    Air Header Flow drops to zero when compressor unloads

    I am replacing most of the major components on an Instrument Air system for a two unit power plant. Each unit has two compressors, one receiver (137 cu ft), and one internally heated desiccant dryer. The systems are crosstied and a single compressor is normally used to provide air for both...
  13. rcchap

    hindsight- how to avoid repeat of Fukushima

    Correct Zogzog. All of my statements above apply only to the light water civilian nuclear power plants in the US, and are not meant to be applied to any other type of reactor.
  14. rcchap

    Japanese nuclear accident FAQ

    trottiey: Nice job on the Q&A. It makes be sick to watch the mainstream media interview a UCS physicist or a politician as a nuclear industry "expert". It is important to get the facts out there. Printing724: Keep in mind that sub plants are PWRs, so you have the capability to remove heat...
  15. rcchap

    hindsight- how to avoid repeat of Fukushima

    There are a lot of interesting ideas stated above. I certainly don't want to discourage discussion, but unfortunately most of the suggestions above won't work. I have worked in the nuclear industry for 13 years, so here are the facts and my 2 cents: - Fukushima was hit with a beyond design...
  16. rcchap

    On Radio Today: Help Wanted Ad for Nukes

    All of the above. TVA is starting the process of completing the Bellefonte units near Hollywood AL. They will be needing hundreds of engineers and craft to finish these. Then TVA will need to staff up the entire plant. Then there are the AP1000s that will be built at plant Vogtle in Georgia...
  17. rcchap

    Hydrotest pressure

    What is your design pressure and temperature, and pipe material, size, and schedule? What is the test temperature? Do you have expansion joints or other components in the system with lower ratings that could be exceeded? Your statement that the hydro test pressure brings you to within 2000...
  18. rcchap

    Hydraulic Design 101 - Air at Highpoint

    I forgot to mention in my reply above that the Froude number criteria were developed for air or nitrogen in a water system. The concept would be the same for other fluids, but the values might be different. These tests were also at lower pressures. cloa, it is 0.35 to 1.0. At a Froude number...
  19. rcchap

    Hydraulic Design 101 - Air at Highpoint

    The criteria I have used to determine how a void travels in a piping system is to calculate the Froude number of the flow. N_Fr = U / SQRT(gD) where U is velocity, g is gravitational acceleration, and D is inside pipe diameter. It has been shown experimentally that when the Froude number...
  20. rcchap

    Jobs in nuclear engineering

    Welcome to the industry gatevalve1982! I also work for a nuclear engineering company as a design engineer. I have done design engineering for the last 12 years and I love it. One thing I have noticied for our new hires, since we are an engineering contracting company, is that it takes longer...

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