ML060250288

01-23-06 Ltr R. Webb to N. Lauben Thermal/Hydraulics Calculation

ML060250288
Person / Time
Site:	Three Mile Island
Issue date:	01/23/2006
From:	Webb R Studies of Nuclear Hazards & Constitutional Law
To:	Lauben N Office of Nuclear Regulatory Research
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ML060230218	List: ML060200058 ML060200059 ML060250281 ML060250286 ML060250288 ML060270341 ML060320530 ML060330052 ML060330055 ML060330057 ML060540057 ML060550444 ML061460509
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Download: ML060250288 (2)

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24-JAN-06 21 :29 DR. R. WEBB - 249 08262 960236 S.01 To. Norm Lauben Office of Research NRC From: Richard Webb Date: Jan. 23, 2006.

In my call to you I mentioned a thermal/hydraulics calculation which I made rec:.r.tly, related to a BWER LOCA without scram. I think I did not describe the calculation and re AIt adequately. I fear that I gave you the impression that I calculated that the amount of waler in the core coolant channels increases upon a steam line rupture. But if you recall carefull',. I characterized the calculation as an "upper-bounding" calculation (for the purpose of gai ning some in-sight as to the behavior of the coolant in the core channels). To be more descri;itie.c.

lest I mislead you, I assumed in my simple model that, as a result of a steam pipe rupture.,

there will be an increase in the mass flow from the core. I then assumed - the upper boi..nding assumption - that the core inlet pressure and inlet enthalpy of the reactor coolant remains constant, only the mass flow rate up the core coolant channels is increased; and I further assume that the core fission power remains constant, all assumption, only to get a feel fP-r the change in the quantity (mass) of R20 in the core. My calculation is a stead-state calculation, so that the mass flow rate is a parameter.

I calculated that the mass of water in the fuel channel decreases with increasing channel flow, but very slightly, and that thei density variation from inlet to outlet hardly changes, though I nearly doubled the mass flow. So, the calculation only provides some physical in-sight. I think that the core inlet pressure will also fall with the steam line br: ak. so that there will probably be more steam formation in the channels. This would mean, a dr.,p in the fission power, but then there might be a surge of water up the channels, when the heti. flux falls off, and then a rise in the fission power, perhaps some kind of rapid and maybe divergent, power oscillation; though there is a time constant for heat transfer from U02 to) the coolant. Then there could be oscillations from one region of the core to another. It wol. Id be a very complicated, but interesting, calculation.

I send you this note, only to be sure that I have not misled you by my small repolt I have to worry about high telephone expenses when I call, and I think I hurried too much.

Would you be interested in undertaken with Ralph Meyer, and Dr. Roger Mattso'n (I assume and hope that he is well, though retired from the NRC), a review of the actions performed on the reactor of TMI-2 reactor system after the first 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of the TM1-2 accident, until say, June 30, 1979 and the recorded data of measurements and graph recordings, and also the log books, and other documents that recorded the actions taken, as well as the papers of proposed actions, and analyses of persons and groups, as the Industry Advisory Group, with the object of writing a full account of the reactor behavior and ac'.ions performed on the reactor after the I" 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of the accident? For an adequate scientiftc and engineering account of that also-critical period appears not be written down in a treatise.

Since you and Ralph Meyer were involved in the TMI accident, as was also Dr. klattso!L, you three would be right for making the needed written, official account.

With this fax, I am faxing you a copy of a letter I am sending to the PDR with a request for documents. Can you help me get this information/documents, inasmuch as aouo

24-JAN-06 21:30 DR. R. WEBB +49 08262 960236 S . 02 I I started off the conference on January 9w", informing me that the thermocouple data is available, and that I can have it.

Sincerely yours, Richard Webb