ML19319C167: Difference between revisions
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- u.s.Nuctaan macut.Arenv ceuuissicN cCedT NuM*SR Naccorw h5 fy - 3 aff I | - u.s.Nuctaan macut.Arenv ceuuissicN cCedT NuM*SR Naccorw h5 fy - 3 aff I | ||
:,:n . | :,:n . | ||
' NRC OISTRIBUTION son PART 50 DCCKET 'ethTERIAL l RCM: | ' NRC OISTRIBUTION son PART 50 DCCKET 'ethTERIAL l RCM: | ||
E Mr. Jphn F. Stolz Toledo Edison ^3/T7fS" 1 f Toledo, Ohio 43652 Lowell E. Roe T/N/ N i Cue cnizso pace meuTpenu suusan er cca+es asesivsc - | E Mr. Jphn F. Stolz Toledo Edison ^3/T7fS" 1 f Toledo, Ohio 43652 Lowell E. Roe T/N/ N i Cue cnizso pace meuTpenu suusan er cca+es asesivsc - | ||
b- sn | b- sn geniciaAi. | ||
geniciaAi. | |||
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:asesisticN Consists of Tech Specs change to page 3/4 3-13 and associated safet'; evaluation regarding grid stability modificat. ions to increase certain saf ety marges f5r Unit 1... l I | :asesisticN Consists of Tech Specs change to page 3/4 3-13 and associated safet'; evaluation regarding grid stability modificat. ions to increase certain saf ety marges f5r Unit 1... l I | ||
1p 2p j l | 1p 2p j l | ||
t I | t I | ||
I i | I i | ||
?LNC NAME: DAVIS-BESSE UNIT # 1 l Jcm 11/02/-77 l I d1 GNLL R ec 'A 5 I i | |||
?LNC NAME: DAVIS-BESSE UNIT # 1 l Jcm 11/02/-77 l | |||
I d1 GNLL R ec 'A 5 I i | |||
9Arr Y FCR ACCN/INFGRMAT:CN i | 9Arr Y FCR ACCN/INFGRMAT:CN i | ||
I ,5 to L.T I I 9PXTCH CMTEF . I M i t i # | I ,5 to L.T I I 9PXTCH CMTEF . I M i t i # | ||
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. I l i I | . I l i I | ||
i i e i | i i e i | ||
, I I I i | |||
, I I I | N i i i l | ||
7 % .NTER NAt. CIST RIEUTICN i LI REG ?!!.2 T i i ! I I I f i | 7 % .NTER NAt. CIST RIEUTICN i LI REG ?!!.2 T i i ! I I I f i | ||
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M i l i II3E'iHU~ l i I t . | M i l i II3E'iHU~ l i I t . | ||
t I e i i i I , | t I e i i i I , | ||
i 15HA0 i 4 63AER I I I I ! 1 | i 15HA0 i 4 63AER I I I I ! 1 1 | ||
l i i SUTLIR I i 1 l } | |||
i i SUTLIR I i 1 l } | |||
i t GR TS I l l 4 I i i l | i t GR TS I l l 4 I i i l | ||
~ EL'i5 I t I i i t , | ~ EL'i5 I t I i i t , | ||
Line 70: | Line 54: | ||
i I t i I i | i I t i I i | ||
[ t 6 I t I i I i | [ t 6 I t I i I i | ||
} EX ERNAL OISTRIBU ICN l CONTRCL NUMBE R I | } EX ERNAL OISTRIBU ICN l CONTRCL NUMBE R I I i 'MP : l'T. C Li Alt 0Al 5 db t y~ | ||
I i 'MP : l'T. C Li Alt 0Al 5 db t y~ | |||
l I InC 1 'l i I 4 .SS:: , i i i f i16 CYS AC35 SE'C CA~EUCRY 4, 1 1 h | l I InC 1 'l i I 4 .SS:: , i i i f i16 CYS AC35 SE'C CA~EUCRY 4, 1 1 h | ||
' ~ | ' ~ | ||
8001310[2 8 | 8001310[2 8 | ||
m '1 a .a.' p 7 ~ " r. - , r I z..i t-. U. | m '1 a .a.' p 7 ~ " r. - , r I z..i t-. U. | ||
a,-it | a,-it | ||
. i 7,d L a d I l'5! l (;u / ' | . i 7,d L a d I l'5! l (;u / ' | ||
TOLEDO Docket No. 50-346 EDISON Serial No. 396 LOWELL E. RCE v.c, ... , | TOLEDO Docket No. 50-346 EDISON Serial No. 396 LOWELL E. RCE v.c, ... , | ||
october 27, 1977 ,,c ... ., e .. ..oo-,,, | october 27, 1977 ,,c ... ., e .. ..oo-,,, | ||
f 419125 9- 5242 s | f 419125 9- 5242 s | ||
<\ \ l(), / | <\ \ l(), / | ||
^ n A ' | ^ n A ' | ||
Director of Nuclear Reactor Regulation tf[C6g'A, 's, /,9 Attention: Mr. John F. Stolz, Chief 'f | Director of Nuclear Reactor Regulation tf[C6g'A, 's, /,9 Attention: Mr. John F. Stolz, Chief 'f | ||
[D.f fjg /f M, 7 L | [D.f fjg /f M, 7 L Light Water Reactors Branch No. 1 Division of Project Management gf_ "'#' 7Rg% [' | ||
Light Water Reactors Branch No. 1 Division of Project Management gf_ "'#' 7Rg% [' | |||
United States Nuclear Regulatory Commission 4. *8 Q N Washington, D. C. 20555 s.~4 _ ,'s | United States Nuclear Regulatory Commission 4. *8 Q N Washington, D. C. 20555 s.~4 _ ,'s | ||
&., \ e | &., \ e | ||
==Dear Mr. Stolz:== | ==Dear Mr. Stolz:== | ||
Line 108: | Line 76: | ||
Our letter to you dated July 18, 1977, regarding grid stability at Davis-Besse Nuclear Power Station Unit No. I proposed some modifications to increase certain safety margins. One of the changes requires a change to the Davis-Besse Nuclear Power Station Unit No. 1 Technical Specifications. Enclosed is the requested change to Page 3/4 3-13 and associated safety evaluation. This change is requested on an emergency basis to allow operation of Davis-Besse Nuclear Power Station Unit No. 1 in a manner which better assures plant operability during grid voltage degradation. | Our letter to you dated July 18, 1977, regarding grid stability at Davis-Besse Nuclear Power Station Unit No. I proposed some modifications to increase certain safety margins. One of the changes requires a change to the Davis-Besse Nuclear Power Station Unit No. 1 Technical Specifications. Enclosed is the requested change to Page 3/4 3-13 and associated safety evaluation. This change is requested on an emergency basis to allow operation of Davis-Besse Nuclear Power Station Unit No. 1 in a manner which better assures plant operability during grid voltage degradation. | ||
Yours very truly, | Yours very truly, | ||
,/ | ,/ | ||
g g pc Attachments: | g g pc Attachments: | ||
Davis-Besse Unit No. 1 Technical Specification Page 3/4 3-13 Safety Evaluation be c/4 THE TCLECC ECISCN CCMPANY EC!SCN PLAZA 3CO VACISCN AVENUE TCLECO. CHIO a3652 | Davis-Besse Unit No. 1 Technical Specification Page 3/4 3-13 Safety Evaluation be c/4 THE TCLECC ECISCN CCMPANY EC!SCN PLAZA 3CO VACISCN AVENUE TCLECO. CHIO a3652 | ||
Safety Analysis A result of our review of " Millstone Grid Stability Syndrome" was addi-tional undervoltage relaying on the 4.16 KV essential switchgear. | Safety Analysis A result of our review of " Millstone Grid Stability Syndrome" was addi-tional undervoltage relaying on the 4.16 KV essential switchgear. | ||
Serials 179 and 226 to the NRC explained that the relays functioned on 90% voltage and a 10 second time delay to trip incoming 4.16 KV source breakers. In addition a 1 second time delay was added to the diesel generator breaker closure, only if the diesel had been started and was ready to accept load. | Serials 179 and 226 to the NRC explained that the relays functioned on 90% voltage and a 10 second time delay to trip incoming 4.16 KV source breakers. In addition a 1 second time delay was added to the diesel generator breaker closure, only if the diesel had been started and was ready to accept load. | ||
Line 120: | Line 85: | ||
The reduction in trip time from 10 to 9 seconds on 4.16 KV voltage relays 27A-1 through 27A-4 and the reduction in close time from 1 to .5 seconds on the diesel generator breaker was to assure ECCS injection within 30 seconds. The table below compares the old scheme with the new scheme. | The reduction in trip time from 10 to 9 seconds on 4.16 KV voltage relays 27A-1 through 27A-4 and the reduction in close time from 1 to .5 seconds on the diesel generator breaker was to assure ECCS injection within 30 seconds. The table below compares the old scheme with the new scheme. | ||
Time After LOCA In Seconds Occurrence Old New LOCA occurs 0 0 LOCA detected and diesel generator started 5 5 System voltage less than 90%, greater than 59% 5 5 Voltage monitoring operates to open off-site source breakers 15 14 Diesel genera *.or at voltage and frequency 15 15 Bus voltage decay and spurious dip allowance 16.5 15 Diesel generator breaker closed 16.5 15 High pressure injection pump starts - second step of diesel generator sequence 21.5 20 Low pressure injection pumps starts - third step of diesel generator sequence 26.5 25 High pressure injection pump up to speed 26.5 25 Low pressure injection pump up to speed 31.5 30 l | Time After LOCA In Seconds Occurrence Old New LOCA occurs 0 0 LOCA detected and diesel generator started 5 5 System voltage less than 90%, greater than 59% 5 5 Voltage monitoring operates to open off-site source breakers 15 14 Diesel genera *.or at voltage and frequency 15 15 Bus voltage decay and spurious dip allowance 16.5 15 Diesel generator breaker closed 16.5 15 High pressure injection pump starts - second step of diesel generator sequence 21.5 20 Low pressure injection pumps starts - third step of diesel generator sequence 26.5 25 High pressure injection pump up to speed 26.5 25 Low pressure injection pump up to speed 31.5 30 l | ||
bt c/6 | bt c/6 l | ||
i | |||
,}} | ,}} |
Latest revision as of 06:21, 1 February 2020
ML19319C167 | |
Person / Time | |
---|---|
Site: | Davis Besse ![]() |
Issue date: | 10/27/1977 |
From: | Roe L TOLEDO EDISON CO. |
To: | Stolz J Office of Nuclear Reactor Regulation |
Shared Package | |
ML19319C168 | List: |
References | |
396, NUDOCS 8001310526 | |
Download: ML19319C167 (4) | |
Text
DISTRIBUTICN AFTER ISSUAN OF OFr.RATI'iG LICENSE
- u.s.Nuctaan macut.Arenv ceuuissicN cCedT NuM*SR Naccorw h5 fy - 3 aff I
- ,:n .
' NRC OISTRIBUTION son PART 50 DCCKET 'ethTERIAL l RCM:
E Mr. Jphn F. Stolz Toledo Edison ^3/T7fS" 1 f Toledo, Ohio 43652 Lowell E. Roe T/N/ N i Cue cnizso pace meuTpenu suusan er cca+es asesivsc -
b- sn geniciaAi.
- c=>-
Xvactessinino / 5 ,, o m e o ENC.csuME
- asesisticN Consists of Tech Specs change to page 3/4 3-13 and associated safet'; evaluation regarding grid stability modificat. ions to increase certain saf ety marges f5r Unit 1... l I
1p 2p j l
t I
I i
?LNC NAME: DAVIS-BESSE UNIT # 1 l Jcm 11/02/-77 l I d1 GNLL R ec 'A 5 I i
9Arr Y FCR ACCN/INFGRMAT:CN i
I ,5 to L.T I I 9PXTCH CMTEF . I M i t i #
I
. I l i I
i i e i
, I I I i
N i i i l
7 % .NTER NAt. CIST RIEUTICN i LI REG ?!!.2 T i i ! I I I f i
, :.nu rux l ! ! I i i f
I i I i i t CE 10) I I i i l : 1 i i s2LJ
' : :4XirJER I l ! I I I t i
i i i i ! t
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M i l i II3E'iHU~ l i I t .
t I e i i i I ,
i 15HA0 i 4 63AER I I I I ! 1 1
l i i SUTLIR I i 1 l }
i t GR TS I l l 4 I i i l
~ EL'i5 I t I i i t ,
i l I i I i i
' i J. Mc G ecGW i l '
I I I I I i 6 l ! I l l i I i i 4 l l i i l l l I l I i l
i I t i I i
[ t 6 I t I i I i
} EX ERNAL OISTRIBU ICN l CONTRCL NUMBE R I I i 'MP : l'T. C Li Alt 0Al 5 db t y~
l I InC 1 'l i I 4 .SS:: , i i i f i16 CYS AC35 SE'C CA~EUCRY 4, 1 1 h
' ~
8001310[2 8
m '1 a .a.' p 7 ~ " r. - , r I z..i t-. U.
a,-it
. i 7,d L a d I l'5! l (;u / '
TOLEDO Docket No. 50-346 EDISON Serial No. 396 LOWELL E. RCE v.c, ... ,
october 27, 1977 ,,c ... ., e .. ..oo-,,,
f 419125 9- 5242 s
<\ \ l(), /
^ n A '
Director of Nuclear Reactor Regulation tf[C6g'A, 's, /,9 Attention: Mr. John F. Stolz, Chief 'f
[D.f fjg /f M, 7 L Light Water Reactors Branch No. 1 Division of Project Management gf_ "'#' 7Rg% ['
United States Nuclear Regulatory Commission 4. *8 Q N Washington, D. C. 20555 s.~4 _ ,'s
&., \ e
Dear Mr. Stolz:
- ' & , , . -(\
Our letter to you dated July 18, 1977, regarding grid stability at Davis-Besse Nuclear Power Station Unit No. I proposed some modifications to increase certain safety margins. One of the changes requires a change to the Davis-Besse Nuclear Power Station Unit No. 1 Technical Specifications. Enclosed is the requested change to Page 3/4 3-13 and associated safety evaluation. This change is requested on an emergency basis to allow operation of Davis-Besse Nuclear Power Station Unit No. 1 in a manner which better assures plant operability during grid voltage degradation.
Yours very truly,
,/
g g pc Attachments:
Davis-Besse Unit No. 1 Technical Specification Page 3/4 3-13 Safety Evaluation be c/4 THE TCLECC ECISCN CCMPANY EC!SCN PLAZA 3CO VACISCN AVENUE TCLECO. CHIO a3652
Safety Analysis A result of our review of " Millstone Grid Stability Syndrome" was addi-tional undervoltage relaying on the 4.16 KV essential switchgear.
Serials 179 and 226 to the NRC explained that the relays functioned on 90% voltage and a 10 second time delay to trip incoming 4.16 KV source breakers. In addition a 1 second time delay was added to the diesel generator breaker closure, only if the diesel had been started and was ready to accept load.
In Serial 293 to the NRC we responded that the changes in 4.16 KV protec-tion did not adversely affect the safety analysis. However, to increase our margin in the safety analysis we proposed slightly more conservative settings of less than 90% 4.16 KV for 9 seconds and diesel generator breaker closure delay of .5 seconds.
The reduction in trip time from 10 to 9 seconds on 4.16 KV voltage relays 27A-1 through 27A-4 and the reduction in close time from 1 to .5 seconds on the diesel generator breaker was to assure ECCS injection within 30 seconds. The table below compares the old scheme with the new scheme.
Time After LOCA In Seconds Occurrence Old New LOCA occurs 0 0 LOCA detected and diesel generator started 5 5 System voltage less than 90%, greater than 59% 5 5 Voltage monitoring operates to open off-site source breakers 15 14 Diesel genera *.or at voltage and frequency 15 15 Bus voltage decay and spurious dip allowance 16.5 15 Diesel generator breaker closed 16.5 15 High pressure injection pump starts - second step of diesel generator sequence 21.5 20 Low pressure injection pumps starts - third step of diesel generator sequence 26.5 25 High pressure injection pump up to speed 26.5 25 Low pressure injection pump up to speed 31.5 30 l
bt c/6 l
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