ML20090G556
| ML20090G556 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/18/1983 |
| From: | Rubenstein L Office of Nuclear Reactor Regulation |
| To: | Lainas G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17139C189 | List:
|
| References | |
| FOIA-84-105 NUDOCS 8308260222 | |
| Download: ML20090G556 (2) | |
Text
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ty AUG 181983 MEM0PM DUf! FOR:
G. C. Lainas. Assistant Director for Operating Reactors, DL FROM:
L. S. Rubenstein, Assistant Director for Core and Plant Systens. DSI
SUBJECT:
SINGLE LOOP OPERATION FOR BWRs
Reference:
Menorandin fron L. S. Rubenstein to C. C. Lainas " Single Loop Operation for BURS", July 27, 1983.
In ny nenorandun of July 27, 1983 we agreed with your proposal to issue single 1000 anendnents for Browns Ferry Units 1, 2, and 3 with the proviso that they complete a successful single loop test. The acceptance criteria for the TVA test has been developed by CPS in conjunction with our contiactor, ORNL, and are given below:
Test data at three single-loop power levels and flows, one at 50% power, one at miniaun pump speed, and one in between are to be taken by movinc along the power / flow limit line while maintaining reasonably constant rod position.
1.
The first criterion requires that all three DR's shall be less than 0.75.
2.
The second criterion requires the trend of the three readings to be taken into account, e.g.:
a.
Suppose all three DRs are the sane.
If the DR is u.75 the test is successful.
b.
Suppose there is a rising trend as power increases: low DR at low flow, higher DR at higher flow / higher power.
So long as the 50%
power DR is"0.75, SLO is acceptable up to 50% power.
c.
Suppose there is a decreasing trend as power increases: higher DR at pump minimun, lower DR at 50% flow.
Operation is acceptable fron minintn par.p speed to (probably) SO% flow. Additional measurements would be required for ths latter. D*! should be extrapolated to lower flows - if >0.75 is predicted for flows <"the mininun", then operation i
below such flows should be prohibited.
d.
Seppose DR is low at the extrenes and high in the niddle.
If the midd?e reading is close to 0.75 it would be hard to assune this bound l
was not exceeded at sone point. Additional test points would be required.
1
Contact:
G. Schwenk, CPB:DSI X-29421
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The test should be conducted in the following manner:
1.
Chart traces should be taken of neutron noise for a few seconds as each test condition is approached, using paper speeds of about b inch /sec.
On-line assurance should he obtained that noise is randon and does not exhibit a relatively pure sine wave at any frequency in the range 0.?-1 hz.
Such a trace as the latter would indicate a dominant mode and approach to instability. The peak-to-peak magnitude of neutron noise should not exceed 15% of the ac level at any time during the tests.
2.
The najor portion of the criteria are based upon measured decay ratios.
These will be detemined at Oak Ridge using cutput data frem the tests, and can be available in 3-4 days following the test period. The reactivity coefficients at the time of the test as well as the test data the,selves will be required by ORNL to analyze the data.
5 L. S. Rubenste n, ssistant Director for Core and Plant Systens, DSI DISTRIBUTION:
CENTRAL FILE CPB:rf L. RUBENSTEIN C. BERLINGER L. PHILLIPS G. SCHWENK R. MATTSON
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