ML20041D812
| ML20041D812 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 03/04/1982 |
| From: | Linder F DAIRYLAND POWER COOPERATIVE |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| LAC-8131, NUDOCS 8203090258 | |
| Download: ML20041D812 (5) | |
Text
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DlDA/RYLAND h
[k COOFERAT/VE pO Box 8i7 2615 EAST AV SOUTH = LA CROSSE WISCONSIN $4601 (608) 788 4 000 March 4,1982 In reply, please refer to LAC-8131 DOCKET NO. 50-409 Director of Nuclear Reac+9r Regulation ATIN:
Mr. Dennis M. Crucchfield 0) p Operating Reactors Branch #5 Division of Operating Reactors
(
U. S. Nuclear Regulatory Commission R
Washing +on, D. C.
20555 O
bh
SUBJECT:
DAIRYLAND POWER COOPERATIVE 8
LA CROSSE BOILING WATER REACTOR (LACBWR) gp PROVISIONAL OPERATING LICENSE NO. DPR-45 f
APPLICATION FOR AMENDMENT TO LICENSE 4
ADDITIONAL INFORMATION e3
REFERENCE:
(1) DPC Letter, LAC-8109, Linder to Crutchfield, dated February 23, 1982.
Gentlemen:
This submittal is to update the information provided in Reference 1 to the present and to provide additional comparisons between the present indicated fuel condition and that observed at the end of Cycles 5 and 6.
On February 18,1982 at 1942 hours0.0225 days <br />0.539 hours <br />0.00321 weeks <br />7.38931e-4 months <br />, the LACBWR experienced a scram from 75%
power.
The scram recovery proceeded normally and the reactor was restarted at 1932 hours0.0224 days <br />0.537 hours <br />0.00319 weeks <br />7.35126e-4 months <br /> on the 18th, Power was escalated slowly over the next several days reaching 83% of rated power on the 22nd of February. On February 24th at 0902 hours0.0104 days <br />0.251 hours <br />0.00149 weeks <br />3.43211e-4 months <br />, one of the two forced circulation pumps tripped and reactor power was reduced ra a., co 48% of rated power. After the recirculation pump was r
restarted power was again escalated slowly to 84.9% of rated power on the 28th of February and subsequently on the 1st of March reduced to the present operating power of 81.6%.
During the return to power af ter the February 18th shutdown the offgas activity was observed to be somewhat higher than during previous steady sta*e operation but much less than Technical Specification limits. On February 28th the indicated offgas activity peaked at 387 Ci/ day on the Tracerlab Channel and 323 Ci/ day on the Victoreen Channel and is currently approximately 353 and 265 C1/ day respectively at 81.6% power. This increase in the offgas activity could indicate the development of small perforation type defects in a small number (17) fuel rods but during the same time no significant increase has been observed in the iodine activity in the reactor coolant.
The nost recent (March 3rd) values for this indication of fuel condition are 1.50E-2 pCi/g Dose Equivalent I-131 and 1.544 E-3 pCi/g for 1-131 activity.
WP1 1_
h \\
l 8203090258 820304 PDR ADOCK 05000409 P
Mr. Dennis M. Crutchfield March 4, 1982 U. S. Nuclear Regulatory Commission LAC-8131 In Table I (attached) we have presented a more detailed comparison of the present estimated fuel condition with that at the end of Cycles 5 and 6 and also a comparison of the range of the parameters indicative of fuel condition during the last two months of each cycle. Several points of interest are evident in this data. All of-the current values for these parameters are much smaller than those for Cycle 5 when detailed fuel examination and dry sipping indicated approximately 22 defective fuel rods. All of the current values and the upper range of values are also significantly less than.or equal to those observed in Cycle 6 (when only one defective fuel rod was identified), except f or the of fgas activity indicatd by the Tracerlab Channel during the last few days. There was also much better agreenent between the Tracerlab.and the Victoreen data during previous operation than at the present time. This would indicate that possibly the Tracerlab equipment is indicating an erroneously high value for offgas activity at this time.
1 In Table II (attached) we have presented data indicating the peaking of I-131 activity in the reactor coolant after reactor scrams or major power perturbations. This data also indicates that the present LACBWR fuel condition is no worse than that at the end of Cycle 6 and much better than at 4
the end of Cycle 5.
Using the information presented in Tables I and II, our best estimate of the number of defective fuel rods in the LACBWR core at this time is one. A worut case estimate based on the high offgas activity indicated by the Tracerlab Channel and the correlation presented in Reference 1 would be 7 defective 1
fuel rods.
We believe that any defects that may be present are small perforations or cracks in the clad that do not expose fuel to the coolant since the coolant e/y and/or a activity are quite low. We believe that this is an acceptable condition for the limited additional operation planned for 4
this fuel cycle. We will continue to monitor the fuel condition very closely and will take appropriate action if significant additional fuel deterioration is indicated.
In order to place a more conservative upper limit on fuel degradation for the renainder of Fuel Cycle 7, we suggest that the limit in LACBWR Technical Specification 4.2.2.22 for off-gas activity be changed from 750'Ci/ day to 571 Ci/ day for the limited extended operation of Cycle 7.
This is the same limit imposed for extended operation at the end of Cycle 6.
(Reference LACBWR Technical Specifications.)
-The information submitted in this letter has been reviewed by the LACBWR Committees as prescribed in Technical Specifications.
If there are any questions concerning this submittal, please contact us.
WP1,
b Mr. Dennis M. Crutchfield March 4, 1982' U. S. Nuclear Regulatory Comission LAC-8131 4
i Very truly yours, I
DAIRYLAND POWER 00 PERATIVE b
-cb-i Frank Linder, General Manager i
FL:SJR:eme
Enclosures:
Tables I and 11 i
cc:
J. G. Keppler, Regional Director, NRC-DR0 III NRC Resident Inspector STATE OF WISCONSIN )
)
COUNTY OF LA CROSSE )
Personally came before me this 6 day of March,1982, the above named Frank Linder, to ne known to be the person who executed the foregoing instrument and acknowledged the same.
Et,s //
re Notary Public,[y6 Crosse County, Wisconsin My Commission Expires 2/26/84.
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TABLE I:
INDICATORS OF FUEL PERFORMANCE IN THE LACBWR(I)
Condition Cycle 5 Cycle 6 Cycle 7(2)
No. of Assemblies defective at End of Cycle 17 1 Probable No. of Assemblies with Visible Defects 7
0 Total No. of Visibly Defective Fuel Rods 12 0
Estimated Total No. of Defective Fuel Rods 22 1
- 1 Scrams while at Power 12 14 12 Startups from Cold Condition 6
7 4
Reactor Power at End of Cycle (% of Rated Power) 49%
76%
81.6%
3 Normalized E0C Off-Gas Activity after 150 ft Holdup Tank (Ci/ day) 591 T 368(3)
T 433(3)
V 336
-V 325 Range of Normalized Off-Gas Activity during Last 2 Months 490-714 T 308-508 T 222-455 of Cycle (Ci/ day)
V 314-502 V 235-380 Normalized E0C Primary System Gross S/y Activity (pCi/g) 6.3 1.1 1.1 i
Range of Normalized Pri. Sys. Gross 8/y Activity During Last 2 Months of Cycle (pCi/g) 2.7 - 7.5
.4 - 1.6-
.7 - 1.3 Normalized E0C Primary System I-131 Activity (uCi/g) 19.0E-3 2.8E-3 2.0E-3 Range of Nor. Pri. Sys. I-131 Act. during Last 2 Months of Cycle (pCi/g)
(11.2-21.4)E-3 (1.0-3.0)E-3 (1.8-2.7)E-3 The Reactor Coolant and Off-Gas Activity Data are normalized to 100% of Rated Power by a linear relationship.
The Reactor Coolant and Off-Gas Activity Data for Cycle 7 are the averages for the latest 3 days (Mar.1 thru Mar. 3, 1982) or the range in the valves..for the last 2 months.
(3) T indicates data from the Tracerlab Channel, and V indicates data from the Victoreen Channel.
TABLE II: 1-131 PEAKIt!G IN L ACBWR REACTOR. COOLANT AFTER PERTURBATIONS IN REACTOR OPERATIONS CYCLE 5 CYCLE 6 CYCLE 7 3/9/78 - 3/25/79 5/25/79 - 11/9/80 1/11I81toPresent 19.5E-3 pCi/g 2.2 hrs after No detectable I-131 peaking after normal shutdown scrams during first 8 months of on 4/27/78 Cycle.
20.1E-3 pCi/g 4.7 hrs after scram on 7/1/78 5.9E-3 uCi/g on 8/3/79 during 2.2E-3 pCi/g 4.7 hrs after slow escalation scram on 9/10/81 20.1E-3 pCi/g 2.8 hrs after.
after power re-scram.on 8/15/78 duction on 7/31/79 3.7E-3 pCi/g 4.8 hrs after scram on 10/18/81 45.7E-3 pCi/g 2.6 hrs after 4.7E-3 pCi/g ~
normal shutdown 4.1E-3 pCi/g 2.6 hrs after 4.1 hrs after.
scram on 8/19/78 on 6/2/80 scram on 11/12/81 64.6E-3 pCi/g 4.0 hrs after scram on 8/24/78 7:4E-3 pCi/g 4.4 hrs after 1.4E-3 pCi/g 3.1 hrs after scram on 8/8/80-scram on 12/24/81 118.4E-3 pCi/g 5.9 hrs after normal shutdown 3.3E-3 6Ci/g on 10/23/80 during 3.1E-3 pCi/g 2.4 hrs after on 10/18/78 escalation after scram on 2/18/82 power reduction 19.6E-3 p Ci/g 2.5 hrs after on 10/21/80 5.0E-3 pCi/g 4.2 hrs after rapid scram on 11/18/78-power reduction from 83% to 48% on 2/24/82 79.1E-3 pCi/g 3.1 hrs after (Loss of 1 Recirc.
scram on 1/13/79 Pump)