ML19221A465
| ML19221A465 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/08/1979 |
| From: | Ross D Office of Nuclear Reactor Regulation |
| To: | Mattson R, Stello V, Vollmer R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19221A466 | List: |
| References | |
| NUDOCS 7905230048 | |
| Download: ML19221A465 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION j.Jlh%
- dmpif, j WAsW NG TCN, D. C. 2Cs55 t
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g-*.... f April 8, 1979 NOTE T0:
R. Vollner V. Stello R. Mattson FROM:
D. F.
Ross SURJECT:
FURTHER ADDITION OF BORON TO THE PRIMARY COOLANT SYSTEM Dr. H.
Richings had a tulephone call with B&W this afternoon on the s u'oj ec t of whether it would be copropriate to further borate the primary system.
B&W has expressed a concern, for several days, of a second criticality problem.
Their facis expert advised them that fuel could redistribute.
For example, a change in flow conditions could move fuel around.
The traditional water-zirconium-fuel-poison matrix was discarded; the parametric study of fuel and water only was considered.
The volume ratios of.55 fuel, 45 water, and no control material yielded K=1 (about) at 3000 ppm boron.
The only physical postulate for the increasa in fuel was a collaps-of fuel from zones above.
This is th2 basis for the B&W assertion that, in the interest of safety, additional baron should be added.
Howie recommends that no additional physics calculations are necessary as he basically agrees with the physics, given the fuel situat?on.
I reco:rmend that :
(1) we defer permission to boron until we obtain the results of the next water sample; (2)~ if this samole shows ade-quate voron (2200 ppm) and it also shows no control rod materials, and (3) if by that time we have further documented our percipitation concern, then i don't !.elieve we should baratc.
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