ML19337B493
| ML19337B493 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/11/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8010020650 | |
| Download: ML19337B493 (5) | |
Text
{{#Wiki_filter:a_, TIg n ^' ,,s jo., UNITED STATES j f ;)c( n, NUCLEAR REGULATORY COMMISSION -{ jj wAsmNGTON, D. C. 20555 N'OT/ { September 11, 1980 ii Docket Nos. 50-259 j and 50-250 !ii Mr. Hugh G. Parris Manager of Power Tennessee Valley Authority ? 500A Chestnut Street Tower II -f, Chattanooga, Tennessee 37401 [
Dear Mr. Parris:
The purpose of this letter is to advise you that we may not be able to issue the amendments requested by your lecter of August 6,1980 prior to your projected startup date of 3rewns Ferry Unit No. 2. Your letter of August 6,1980 (TVA SFNP ~lS 143) stated that approval of the Te:hnical Specifications was required for startup of Unit 2 follow-ing the current refueling outage and requested our acoroval by October 10, 1980. Recognizing your need and urgency, we performed an expedited review and transmitted the enclosed ccaments and quastions to your staff on August 26, 1980. On Friday, Septemoer 5,1980 your staff advised us that the cocynon station service transformer for Unit 2 will not be delivered in time to be installed during this outage and that revisions and reanalyses of the material trans-mitted by your August 6,1980 submittal would be required. As of today, we understand that these reanalyses are still in progress anc the extent of the changes and modifications to your submittal cannot as yet be determined. Consequently, the date for the proposed meeting with your ~ staff which had tentatively been scheduled for this week to resolve our comments, has slipped at least several weeks. We have reviewed our workload and available technical resources. The complexity of this project - as evidenced by the time required by your staff to complete the reanalysis - will require a minimum of four weeks on our part - after all issues are resolved - to comolete our review, prepare a safety evaluation and amencment package, etc. Your current schedule indicates that Unit 2 will be ready to start up on Octocer 24, 1980. We must have the revised system analyses and all questions resolved by Septemcer 26, 1980 or there is little probability l l Boloon c,go
- _p i, ^ I; Mr. Hugh G. Parris 5 E= we can issue the proposed amendments by the projected startup date of + 2 Unit 2. We also wish to advise you that if your revised submittal requires essentially a complete rereview by our staff, we will treat 3 it as a new application and will require another Class III fee. 4j Sincerely, t _. A I dP Thomas n. Ippolito, Chief Operating Reactors Branch !2 Division of Licensing i ?
Enclosure:
E Comments and Items for 2 Discussion { cc w/ enclosure: i See next page + .e .k i 5 = = l i m + 1 } 5 .9. 5 i:
.y + 2= 2 Mr. Hugh G. Parris 2 i= 5 cc w/ enclosure: ~~ H. S. Sanger, Jr., Esquire i General Counsel i Tennessee Valley Authority i 400 Commerce Avenue i E llB 33C j Knoxville, Tennessee 37902 +i Mr. Ron Rogers ni Tennessee Valley Authority B 400 Chestnut Street, Tower II i Chattanooga, Tennessee 37401 s Mr. E. G. Beasley F Tennessee Valley Authority i 400 Ccamerce Avenue i W 10C 131C } Knoxville, Tennessee 37902 I h Mr. Herbert Abercrombie [ Tennessee Valley Authority P. O. Box 2000 = s Decatur, Alabama 35602 3 5 Athens Public Library i South and Forrest 5 Athens, Alabama 35611 i Mr. Robert F. Sullivan U. S. Nuclear Regulatory Commission 2 P. C. Box 1863 3 Decatur, Alabana 35602 2 m I i i5 i 5 5 5 5 9 i f
_._4 _ 1 M BROWNS FERRY UNITS 1, 2, AND 3 ti 4 ADEOUACY OF STATION ELECTRICAL DISTRIBUTION SYSTEM VOLTAGES N4 Items to be discussed as a result of Tennessee Valley Authority (TVA) subnittal of August 6,1980
- =
3
REFERENCE:
5 5 TVA l etter, L. M. Mill s, to U. S. NRC, H. R. Denton, August 6,1980, TVA BFNP TS 143. ii M OUESTIONS: =9 1. In Enclosure 1, Table 4.9. A.4.c, " Voltage Relay Setpoints," for the .t second-level /ndervoltage sensing relays, an allowable time delay is hi not given. k'at is it? The same listing shows an overlap between the I.! trip setpoint and reset setpoint. Discuss, primarily, is it possible i for the reset level to be below the trip level or is the reset set- ~;i point a fixed (plus tolerance) percent above the trip setpoint? ilM
- 2., Section 1, NIMV20, uses 160kV as the lowest 161kV switch-7:5 yard voltage, which produces a voltage at the shutdown board of 3782V j
for the steady-state condition. Since the second-level undervoltage = 5 relay trips up to a level of 3845V, it appears some voltage correction is needed to prevent spuricus trips of offsite power to tne shutdown i bo ard s. GCC 17 requires that the probability of losing this second it source of power be minimized. No te that, in the other steady-s ta te studies, the same po tential problem exis ts, and also requires M correction. i: 25
- 3., Section 1, provides.s udies (NIMV 16,17, and 18) which snow that tne 4150/480V transformers need to use the 5% boost tap to i{
provide adequate starting voltages for the.480V buses. This setting fg contributes to overvoltage conditions on the 480V buses in a :ninimum }i load, high grid voltage (110.9% when the grid voltage is 116.5kV,
- ?
113.3% when the grid voltage is 170kV) (study MIMV 15A and 17A). 9E si Discuss the TVA plans to prevent this overvoltage condition while [i correcting the inadequai.: starting voltage probl em. $s 4, Section 1, Page 7, indicates that the minimum degraded .] voltage relay pickup time plus time delay will be approximately li 81/2 seconds. What is the duration of the longest expected motor di starting voltage transient that could operata the trip (3845V)? Will i si this cause a transfer to diesel power? 3 5-
- 5., Section 2:
'5
- Il a.
The analysis requested for where shutdown board interties are j used (for example, shutdown board 0 to shutdown board 3ED) was li not provided. Prov id e. (i b. When will the analysis for voltagas of less than 480V be submitted? .i: QQ O' ~ D du o we e
q _. .in [j -: : El E5 1 i; c. Supply the minimum load /high voltage analysis for the 500kV source il as required by the NRC (August 3,1973 letter). = k=gj d. What are the equivalent voltages (500kV nominal) when using the li on-load tap changing of the unit station service transformers Ei (grid voltage varies cetween 455kV (93%) and 550kV (110%)? Are is these equivalent voltages bounded by the analysis-assumed voltage j) of 490kV (98%) anu the voltage analysis to be provided in c, ?- a bove? ?Iij Per NRC guideline 3 (August 8,1979 letter), what are the analysis e. 55 results when starting tne largest nonsafety load that affects jg che voltage on the shutdown buses? I.; .i) 6. What are the pickup and dropout voltages of the 480V MCC starters and 7f contractors (120V AC circuit)? Can these devices withstand the analyzed ji voltages without overneating, blowing fuses, or dropping out? 35 55 ."= ii.: M .= IF $E ei N ~3 -I -4 5= il Gli M
- .s b
N-Cif4 U. \\.
k -=. si 3ROWNS FERRY DEGRADED GRID ji (Issues to be distussed based on August 5,1980, submittal) a
- r
- .i=
[{, page 6, NIMV 19, 20: += 1. It is stated that, f]r Unit 3, a minimum voltage of 150kV must be 1; maintained to have adequate voltage at the 4150V shutdown boards, tj What are the voltages at the 480V buses and motors at this voltage? IE N 2. In Enclosure 3, section I, NIMV 15, the minimum 161kV voltage is
- 25 stated as being 157.78kV.
In Enclosure 3, section 2, page 9, it is EE stated as being minircum at 160kV. Has the voitage ever been below i 160kV? if so, how often, when, and for what duration? 3 3. If 160kV is the lowest expected grid voltage, and the setpoint to trip
- 3 the offsite source breakers is at our abcut 160kV, why annunciats s
below this value? ed Fi ?. Will the 48CV taps be set at 5". boost? G {3 5. For NIMV 20, taking 150kV as lowest grid voltage, the voltage at the g shutdown board is 3789V. With a voltage band on the relay of 3759 to gg 3845V, i t apoears that spurious trips of the offsite power are to be H expected. As this would be in violation of GDC-17, please justify. ik it S. page 292: No diesel testing that resembles the testing called out in June 3,1977, letter, cosi tion 3. Ej
- 7., page 29a:
3: 15 a. Surveillance Requirements 4.9.A.4a,. b should be monthly per NRC M. positions of June 3,1977. ff 15 b. No requirement for channel check is called out. 15 ?) S., page 297a:
- 5 is a.
LOC 3.9.B.11 does not require tne failed channel to be put it j'i tripped position within one hour or at all. iS b. LOC 3.9.E.11.3 allows all second-level relays to be inoperable ] for five days. Oniv protection is loss of power relays.
- Eil c.
LOC 3.9.3.11.0 allows all VV relays or one bus to be inoperable g for five days. 3 72
- 9., page 2933, Ta bl e 4. 9. A.4.c, i tem 3, : No time delay or il allowable limits defined.
EE Mi 3 2: ? Eh
- =5
,,; 3 +.--w--- w %-ep =,. e -.+* wow +, e - w w. .e%+=+ e ..gsewe - -.e}}