ML19221A248
| ML19221A248 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/19/1979 |
| From: | Mathews P Office of Nuclear Reactor Regulation |
| To: | Stello V Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7905210068 | |
| Download: ML19221A248 (2) | |
Text
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NUCLEAR REGULATORY CO.'. c.ilSSION 3 j. gap 3
AsHINGTON. D. c. 20ss5 Yr% ' {b'h
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April 19. 1979
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MEMOPANDUM FOR:
V.
Ste11o FROM:
P.
R. Matthews I contacted VAPL (E. Venerus, J.
- Sager, G.
Gerber) to request in'ir-mation on ef fectiveness of adding hydrazine (N H4) to the primary 7
systera to scavange oxygen since there is indication of dissolved oxygen in the primary coolant.
I informed them of the oxygen, nitro-gen, and hydrogen content of the primary coalant base on samples taken 4/14 and on 4/15 VAPL called back with the following information or conclusions:
They ques t ioned the val idi ty of the p rima ry coolant samples a.
and recommend that they be verified.
Tney suspect that the samples might have been exposed to air since the oxygen consumption would normally be practically zero anytime the hydrogen concentration is over 15 cc/kg.
b.
However, assuming there is dissolved oxygen in the primary coolant,they consider that the preferred and proven nethod for scavanging oxygen is to maintain dissolved hydrogen concentration at or above 15 cc/kg.
- Further, they believe that addition of hydrazine should be fairly effective in scavanging oxygen.
However, they recommend that hydrazine be added only in slight excess to that necessary to scavange oxygen in order to reduce production o' non-condensible gases as a result of hydrazine decomposition.
Their definition of a slight excess o f hydrazine woul d be a hydrazine concentration in the primary system of about 2 ppm above that necessary to combine with the dissolved oxygen in the system.
For example,with a oxygen concentra-tion o' about 4 cc/kg which would correspond to approximately 7905o10o0
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Stello.
6 ppm oxygen in TMI-2 they would recormend added hydrazine to give 8 ppm concentration.
KAPL indicated that with the primary system in the 2,30-240'F range that the hydrazine will thermally decompose with a half life of about 1-2 hours.
They further indicated that there would probably be som?
radiologic decomposition of hydrazine but they coold not cuantify j
the decomposition rate.
i Y
k u.4<
wJ P.
R. Matthews cc:
T.
Novak T.
Te l f o rd P. Matthews
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