ML20126J596
| ML20126J596 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Calvert Cliffs, Davis Besse, Salem, Oconee, Mcguire, Palisades, Palo Verde, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Sequoyah, Arkansas Nuclear, Summer, Prairie Island, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Farley, South Texas, San Onofre, Cook, Comanche Peak, Fort Calhoun, McGuire, Trojan, Crane  |
| Issue date: | 12/31/1992 |
| From: | Allanach J BRAND UTILITY SERVICES, INC. (BUSI) |
| To: | NRC |
| References | |
| REF-PT21-92 GEN9212-075, GEN9212-75, NUDOCS 9301060216 | |
| Download: ML20126J596 (72) | |
Text
BRAND Utand utnety Services,inc.
Oudity Results from Quaty nmle i
REF: GEN 9212-075 December 31,1992 Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzle dams. While BUSl has not determined this to be a 10CFR21.21(a) reportable nonconforming situation, this Information is being provided to you for information and also to utilities for evaluation.
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold 100 would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing _a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in affected plants. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dam.s during
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E3 RAND 2-Director, Office of Inspection and Enforcement Ref: GEN 9212-075 U.S. Nuclear Regulatory Commission December 31,1992 Modification to the nozzlo dams alon0 with a modification to plant procedures would provent the above described potentialloss of RHR cooling and allow the continued uso of nozzio dams during outa00s. This modification is currently bein0 offorud by BUSI.
If you have any questions, please contact the undersigned.
Very truly yours, b
ohn R. Atlanach General Mana0er Engincored Products Division Brand Utility Services, Inc.
JRA/Im cc:
J. D. Vandor0 rift, ANO 1 J. D. Blossor, Callaway R. A. Fonoch, ANO 2 J. Kolloy, Comancho Peak W. R. McCollum, Catawba A. Blind, D. C. Cook P. F. Mckoo, Crystal River Unit 3 J. A. Widay, Ginna L. F. Storz, Davis-Bosso 1 M. L. Marchi, Kowaunoo J. D. Townsend, Diablo Canyon G. J. Maxfield, Point Beach D. Morey, J. M. Farley 1 & 2 M. Sollman, Prairio Island H. B. Barron, Oconeo C. Vondra, Salem T. G. Brou0 ton, Three Mile Island 1 R. J. Boecken, Sequoyah h
R. E. Denton, Calvert Cliffs 1 & 2 C. S. Hinnant, Harris T. L. Patterson, Fort Calhoun 1 M. R. Wisenburg, STP T. L. McConnell, McGuiro W. R. Robinson, Trojan J. S. Koonan, Millstone Unit 2 J. L, Skolds, V. C. Summer C. H. Clement, Millstone Unit 3 W. B. Shipman, Vogtle G. B. Slade, Palisados O. Maynard, Wolf Crood W. E. Ido, Palo Verdo 1 l
R. K. Flood, Palo Vorde 2 R.- J. Adney, Palo Verde 3 H. E. Morgan, San Onofra 1, 2 & 3 G. J. Boissy, St. Lucio 1 & 2 D. Packer, Waterford 3 i
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4 BRAND utana utmy semen. snc.
ovarity nesuits som ovar,ty twpe REF: GEN 9112 076 December 31,1992 Mr. J. D. Vander0rif t Plant Mana0er, ANO 1 Enter 0y Operations Inc.
Rto. 3, Box 137G Russellvillo, Arkansas 72801
Subject:
Potential Loss of RHR Cooling During Nozzio Dam Removal Gentlemon:
The pu nose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling durin0 the removal of steam Donerator nozzlo dams. This information is being provided to you under the requirements delinoated in 10CFR21.21(b) which regulros BUSI to inform affected customers of this potential situation such that licensees may evaluate tho-situation pursuant to 10CFR21.21(a).
Durin0 refuelin0 activities, nozzio dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzio dams that utilize inflatable seals as the primary scaling mechanism may creato a trapped air column behind the cold 100 nozzle dam. This air column could be created by undetectable minuto leaks of air throu0h the inflatable seals which are typically pressurized to 65 psig (almost 5 timos the hydrostatic ptossure caused by the refueling pool water). Continualleaka00 of air into the cold 100 would eventually evacuate the vertical portion of the cold 100 oadin0 to the RCS l
pump. This evacuation of water could occur within a savon day period. Having an air column in place of water means thoro is loss water available for cooling during mid-loop conditions. Removal of the cold log nozzio dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causin0 a risk of vortexin0 cavitation of the RHR
/
pumps and subsequent loss of RHR coolin0 BUSIis unable to determino if this potential condition would cause loss of RHR coolinD durin0 mid loop operations in your plant. BUSI is recommandin0 to all users of nozzle dams that utilize inflatable seals as the primary scaling mechanisms (BUSI, previously sold as Busitoch; Nuclear Ener0y Services; and Combustion En0lnooring) to review the above concerns relativo to use of nozzlo dams durin0 refuelin0 operations, j
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6 75 Glen Road Sandy Hook. ci 06482 (203)420 9239 Fax (203)420 9829 w..,....,.
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..o BRAND i
s 2-Mr..l.D. Vander0rif t Ref: GEN 9112-076 Plant Manager, ANO 1 December 31,1992 BUSI has developed a modification to existing nozzlo dams and plant procedures that would provent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, Y.
2 ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im oncl.
cc:
US Nuclear Ro0ulatory Commission l
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J E3 RAND Brand uttHty Servmes,Inc.
Ovahty Results hom Ovahty /wple REF: GEN 9112 077 December 31,1992 Mr. R. A. Fenech Plant Mana0er, ANO 2 Entorgy Operations Inc.
Rto. 3, Box 137G Russellville, Arkansas 72801
Subject:
Potential Loss of RHR Cooling Durin0 Nozzio Dam Romoval Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzlo dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluato the situation pursuant to 10CFR21.21(a).
During refuelin0 activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenanco activities while the reactor is bolnD refueled. Nozzlo dams that utilizo inflatable seals as the primary scalinD mechanism may creato a trapped air column behind the cold log nozzle dam. This air column could be created by undetectable minuto leaks of air throu0h the inflatable seals which are typically pressurized to 65 psig (almost 5 timos the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold 100 would eventually evacuato the vertical portion of the cold 1e0 eadin0 to the RCS l
pump. This evacuatinn of water could occur within a sovon day period. Having an alt column in place of water means there is less water available for coolin0 during mid-loop conditions. Removal of the cold leg nozzio dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a lovel below the RHR suction lino causing a risk of vortexin0/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determino if this potential condition would cause loss of RHR cooling durin0 mid loop operations in your plant. BUSl is recommandin0 to all users of nozzio dams that utillzo inflatable seats as the primary sealing mechanisms (BUS 1, previously sold as Busitech; Nuclear Ener0y Services; and Combustion Engineering) to review the above concerns relative to use of nozzio dams durin0 refuelin0 operations.
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d 75 Glen Road Sandy Hook, CT 06482 (203)426 9239 Fax (203) 426-9829 h
BRAND 2-Mr. R. A. Fonoch Ref: GEN 9112 077 Plant Manager, ANO 1 December 31,1992 BUSl has developed a modification to existinD nozzio dams and plant procedures that would provent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
^
LL[]L a ohn R. Allanach General Mana0er EnD ncored Products Division i
Brand Utility Services, Ir :.
JRAllm oncl.
cc:
US Nuclear Regulatory Commission l
BRAND Urand u1\\\\ sty Servsces, Inc.
Qual?ty Results from Ovality 1%ople REF: GEN 9112-078 December 31,1992 Mr. W. R. McCollum Managor, Catawba Nuclear Sito Duke Power Company P.O. Box 250 Clover, South Carolina 29710
Subject:
Potential Loss of RHR CoolinD During Nozzio Dam Rornovel Gentlemon:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissuo related to residual heat removal cooling durin0 the removal of steam Generator nozzlo dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluato the situation pursuant to 10CFR21.21(a).
Durin0 refueling activities, nozzle dams are commonly used to isolato the steam Donorators in order to perform maintenance activities while the reactor is being refueled. Nozzio dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold log nozzlo dam. This air column could be created by undetectable minuto looks of air through the inflatable seals which are typically pressurized to 05 psig (almost 5 times the hydrostatic pressuro caused by the refuelin0 pool water). Continual leaka00 of air into the cold log would eventually evacuate the vertical portion of the cold log leadin0 to the fiCS pump. This evacuation of water could occur within a sovon day period. Having an air column in place of water means thoro is less water available for coolin0 during mid loop conditions. Removal of the cold log nozzlo dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a lovel below the RHR suction lino causino e risk of vortexin0/ cavitation of the RHR pumps and subsequent loss of RHR coolin0 BUSl is unable to determine if this potential condition would cause loss of RHR coolin0 during mid-loop operations in your plant. BUSI is recommendin0 to all users of nozzle dams that utilizo inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitoch; Nuclear Energy Services; and Combustion -
EnD nocrin0) to review the above concerns relativo to use of nozzlo dams during i
refuelin0 bporations, j
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l 75 Glen noad Sandy Hoch, cT e6482 (203)426 9239 f at (203) 420 9829 h
t BRAND 2-Mr. W. R. McCollum Ref: GEN 9112 078 Mana0er, Catawba Nuclear Site December 31,1992 BUSl has developod'a modification to existin0 nozzle dams and plant proceduros that would provent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly your,
~
LK ohn R. Allanach General Manager En0;1oorod Products Division Brand Utility Services, Inc.
JRA/Im oncl.
cc:
US Nuclear Ro0ulatory Commission
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E3 RAND Utand utatsty Services,inc.
Quality Results from Quality People REF: GEN 9112 079 December 31,1992 Mr. Paul F. McKee Director Nuclear Plant Operations, Crystal River Unit 3 Florida Power Corporation P.O. Box 219 Crystal River, Florida 32623 0219
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal coolinD during the removal of steam Generator nozzle dams. This information is bein0 provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refuelin0 activities, nozzle dams are commonly used to isolate the steam generators in order to perforrn maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism-may create a trapped air column behind the cold 100 nozzle dam. This air column could be created by undetectable minuto leaks of air through the inflatable seals which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leadin0 to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling durin0 mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR section line causin0 a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling durin0 mid loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitoch; Nuclear Energy Services; and Combustion En0 reering) to review the ebove concerns relative to use of nozzle dams during l
refueling operations, j
l 5
Ia 75 Glen Road Sandy Hook, CT 06482 (203) 426 9239 ' Fax (203) 426 9829 h
4 8RANO 2-Mr. Paul F. McKee Ref: GEN 9112-079 Director Nuclear Plant Operations, December 31,1992 Crystal River Unit 3 BUSl has developed a modification to existinD nozzle dams and plant procedures that would prevent the above described potentialloss of RHR coolin0. For further information, please contact the undersigned.
Very truly your ch w
hn R. Atlanach General Mana0er Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
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BRAND brand utility berv6ces,Inc.
Qualty Results hom Ovality People REF: GEN 9112 080 December 31,1992 Mr. Louis F. Storz Plant Mana0er, Davis Besse 1 Toledo Edison Company 5501 N. State Route 2 Oak Harbor, Ohio 43449
Subject:
Potential Less of RHR Cooling Durin0 Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling durin0 the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSI to inform af fected customers of this potential situation such that licensees may evaluate the situation pursue't to 10CFR21.21(a).
Durin0 refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealin0 mechanism may create a trapped air column behind the cold leg nozzle dam. Inis air column could be created by undetectable minuto leaks of air throu0h the inflatable seals which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for coolin0 during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSlis unable to determine if this potential condition would cause loss of RHR cooling during mid loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech: Nuclear Ener0y Services; and Combustion En0 neering) to review the above concerns relative to use of nozzle dams during l
refuelin0 operations.
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75 Glen Read Sandy Hook, CT 06482 (203)426-9239 Fax (203) 426 9829 h
BRAND 2-Mr. Louis F. Storz Ref: GEN 9112-080 Plant Mana0er, Davis Besso 1 December 31,1992 BUSI has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
~ bk John R. Allanach General Manager EnD ncered Products Division i
Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Re0ulatory Commission men mim um
e't BRAND Utand utsuty Servsces, tnc.
Quality Results from Quality Feople REF: GEN 9112-081 December 31,1992 Mr. John D. Townsend Vice President & Plant Manager, Diablo Canyon Pacific Gas and Electric Co.
P.O. Box 56 Avila Beach, California 93424
Subject:
Potential Loss of RHR Cooling During Nozzio Dam Romoval Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSl) has identif!ad a potentialissuo related to residual heat removal coolin0 during the removal of steam generator nozzlo dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to Inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
DurinD refueling activities, nozzlo dams are commonly used to isolate the steam Generators in order to perform maintenance activities while the reactor is bolnD refuelod. Nozzle dams that utilizo inflatable seals as the primary scaling mechanism may create a trapped air column behind the cold log nozzio dam. This air column could be created by undetectablo minuto leaks of air throu0h the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressuro caused by the refueling pool water) Continualleakage of air into the cold log would eventually evacuate the vertical portion of the cold log loadin0 to the RCS pump. This evacuation of water could occur within a savon day period. Having an air column in place of water means thoro is loss water available for coolinl during mid loop conditions. Removal of the cold 100 nozzlo dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causing a risk of vortexin0/ cavitation of the RHR pumps and subsequent loss of RHR coolina.
BUSl is unable to determino if this potential condition would cause loss of RHR coolino during mid-loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilizo inflatable seals as the primary scaling mechanisms (BUSl, previously sold as Busitech Nuclear Ener0y Servicos; and Combustion Engineering) to review the above concerns relativo to use of nozzio darns during refueling operations.
j I
i l
75 Glen Road Sandy Hora CT 064B2 (203)426 9239 Fax (203) 426 9829 e
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't BRAND 2-Mr. John D. Townsend Ref: GEN 9112 081 Vice President & Plant Mana0er, December 31,1992 Diablo Canyon BUSl has developed a niodification to existino nozzle dams and plant procedures that would prevent the above described potential loss of RHR coolin0. For further information, please contact the undersi0ned.
Very truly yours, (0
ohn R. Allanach
' General Manager EnD ncered Products Division i
Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Rc0ulatory Commission
p-E3 RAND rand utikty Services,Inc.
Quahty Results from Quably Ptxwle REF: GEN 9112 082 December 31,1992 Mr. Dave Morey Plant Manager, J. M. Farley 1 & 2 Southern Nuclear OperatinD Company P.O. Drawer 470 Ashford, Alabama 3G312
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSl) has identified a potential issue related to residual heat removal coolinD durin0 the removal of steam Donerator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzio dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is bein0 refueled. Nozzle dams that utilire inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold 100 nozzle dam. This air column could be created by undetectable minuto leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate tho vertical portion of the cold 100 eading to the RCS l
pump. This evacuation of water could occur within a sovon day period. Havin0 an air column in place of water means there is less water available for cooling durin0 mid loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS Inventory to suddenly decrease to a level below the RHR suction line causin0 a risk of vortexin0 cavitation of the RHR
/
pumps and subsequent loss of RHR coolin0 BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealin0 mechanisms (BUSl, previously sold as Busitech; Nuclear Ener0y Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations, j
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i i
t 75 Glen Road Sendy Hook, cT 06482 (203)426-9239 Fax (203)426 9829 h
BRAND 2
Mr. Dave Morey Ref: GEN 9112-082 Plant Manager, J. M. Farley 1 & 2 December 31,1992 BUSl has developed a modification to existin0 nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, k
u ohn R. Allanach General Mana0er EnD neered Products Division i
Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission l
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BRAND Utand utth1y Sorytces. inc, Qunhty liesults Itom Qual ty 1%ople REF: GEN 9112 083 December 31,1992 Mr. H. B. Barron Mana0er, Oconco Nuclear Site Duke Power Company P.O. Box 1439 Sonoca, South Carolina 29679
Subject:
Potential Loss of RHR Coolin0 Durin0 Nozzlo Dam Removal Gentlemon:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identiflod a potential issuo related to residual host removal coolin0 durin0 the removat of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
Durin0 refuelin0 activities, nozzio dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is beina refueled. Nozzle dams that utilizo inflatable seals as the primary sealing mechanism may creato a trapped air column behind the cold 100 nozzle dam. This air column could be created by undetectable minuto leaks of air through the inflatable seals which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refuelin0 pool water). Continualleaka00 of air into the cold 100 would eventually evacuate the vertical portion of the cold 100 eadin0 to the RCS l
pump. This ovacuation of water could occur within a savon day period. Havin0 an air column in place of water means thoro is loss water available for coolin0 during mid loop conditions. Removal of the cold log nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causin0 a risk of vortexin0/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unabio to determine if this potential condition would cause loss of RHR coollnD durin0 mid loop operations in your plant BUSl is recommendin0 to all users of nozzle dams that utilize inflatable seats as the primary sealing mechanisms (BUSl, previously sold as Busitoch: Nuclear Energy Services; and Combustion En0ineerin0) to review the above concerns relative to use of nozzlo dams during refuelin0 operations.
}
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1 75 Glen Road Sandy Hook, CT e6487 (203) 42G 9239 Fax (203)426 9829 h
8 RAND 2
Mr. H. B. Barron Ref: GEN 9112 083 Mana0er, Oconee Nuclear Site December 31,1992 BUSl has developed a modification to existin0 nozzle dams and plant procedures that would provent the above described potentialloss of RHR coolin0. For further information, please contact the underslunod.
Very truly yours,
~
b.
Wohn R. Allanach General Mana0er En0ineered Products Division Brand Utility Services, Inc.
JRA/Im oncl.
cc:
US Nuclear Re0ulatory Commission
BRAND Drand utility Serv 6ces,Inc.
Quahty Results from Ovahty People REF: GEN 9112 084 December 31,1992 Mr. T. Gary Broughton Vice President, Throo Milo Island 1 GPU Nuclear Corporation Route 441S, Londonderry Township P.O. Box 480 Middletown, Pennsylvania 17057
Subject:
Potential Loss of RHR CoolinD Durin0 Nozzlo Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzio dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which regulres BUSl to inform affected customers of this potential situation such that licenscos may evaluate the situation pursuant to 10CFR21.21(a).
During refuelin0 activities, nozzio dams are commonly used to isolato the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzlo dams that utilize inflatable seats as the primary sealing mechanism may create a trapped air column behind the cold 100 nozzio dam._ This air column could be created by undetectable minuto leaks of air throu0h the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leaka00 of air into the cold log would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a sovon day period. Having an air column in place of water means there is less water available for coolin0 during mid-loop conditions. Removal of the cold 100 nozzio dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causino a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to dotermine if.this potential condition would cause loss of RHR coolin0 during mid-loop operations in your plant. BUSl is recommending to all users of noule dams that utilize inflatable seals as the primary scaling mechanisms (BUSl, previously sold as Busitoch; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relativo to use of nozzle dams durinD
)
refueling operations.
{
a i
7s Glen Deac Sandy Hook. CT 06482 ' (203) 426 9239 Fax (203) 426 9829 -
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8 RAND 2-Mr. T. Gary Brou0hton REF: GEN 9112 084 Vice President, Three Mile Island 1 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours IL
~
2 l
ohn R. Allanach General Manager Engineered Products D! vision Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
a BRAND Urand utshty semctss,Inc.
Quwty Results from Quahty People REF: GEN 9112 085 December 31,1992 j
Mr. R. E. Denton i
Plant General Manager, Calvert Cliffs 1 & 2 Baltimore Gas & Electric Co.
1650 Calvert Cliffs Parkway Lusby, Maryland 20657
Subject:
Potential 1.oss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activitics, nozzle dams are commonly used to isolate the steam generators in order to perforrn maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to.65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water), Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation'of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilize inflatable seals as the primary scaling mechanisms (BUSI, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations, j
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- 75 G;en Road Sandy Hoot. CT 06482 (203)426-9239 Fax (203)426 9829 h
BRAND 2-Mr. R. E. Denton REF: GEN 9112 085 Plant General Manager, December 31,1992 Calvert Cliffs 1 & 2 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, I
ohn R. Allanach General Manager En0ineered Products Division Brand Utility Services, Inc.
JRAllrn oncl.
cc:
US Nuclear Regulatory Commission
g.,
E3 RAND Urand utlJIty Servbces. Inc.
Cuanty Results from Quality People REF: GEN 9112-086 December 31,1992 Mr. T. L. Patterson Manager, Fort Calhoun 1 Omaha Public Power District P.O. Box 399 Fort Calhoun, Nebraska 68023
Subject:
Potential Loss of RHR Cooling During Nozzio Dam F%moval Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue releted to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform af fected customers of this potential situation such that licensees rnay evaluate the situation pursuant to 10CFR21.21(a).
Durin0 refuelin0 activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seats as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold 100 eading to the RCS l
pump. This evacuation of water could occur within a seven day period. Havin0 an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold log nozzle dam would release this
-trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causin0 a risk of vortexing/ cavitation of the RHR l
pumps and subsequent loss of RHR cooling.
l BUSl is unable to determine if this potential condition would cause loss of RHR coolinD during mid loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion EnDineerin0) to review the above concerns relative to use of nozzle dams during l
refueling operations.
.)
i l
8 75 Gk:n Road Sandy Hock, cT 0f432 (203)420 9239 Fax (203) 426 9329 b
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BRAND Mr. T. L. Patterson REF: GEN 9112 086 Mana0er, Fort Calhoun 1 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR coolin0. For further information, please contact the undersigned.
Very truly yours, John R. Allanach General Manager En0ineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission c
4
$3 RAND Brand utlhty servsces,Inc.
Ovahty Results from Quahty People REF: GEN 9112-087 December 31,1992 Mr. T. L. McConnell Manager, McGuire Nuclear Site Duke Power Company 12700 Hagers Ferry Road Huntersville, North Carolina 28078-8985
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSI to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary seating mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water) Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of tha cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
B'JSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams.that utilize. inflatable seals as the primary sealing mechanisms (BUSi, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
i l
5 l
F k
i 75 Glen Road Sandy Hook, CT C6432 (203)426-9239 Fax (203) 426-9829 h
l
t' BRAND Mr. T. L. McConnell REF: GEN 9112 087 Manager, McGuire Nuclear Site December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
^
{k ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
y E3 RAND Drand utinty Services. Inc.
Quahty Resotts from Quality People REF: GEN 9112-088 December 31,1992 Mr. John S. Keenan Unit Director, Millstone Unit 2 Northeast Utilities P.O. Box 128 Waterford, Connecticut 06385
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seats as the priniary sealing mechanism may create a trapped air column behind the cold leg nozzio dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causira a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling c'uring mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech: Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
j i
)i i
75 G!en Road Sandy Hook cT C6482 (203)426-9239 Fax (203) 426-9829 h
BRAND 2
Mr. John S. Keenan REF: GEN 9112-088 Unit Director, Millstone Unit 2 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
~
ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im oncl.
cc:
US Nuclear Regulatory Commission
BRAND Brand utility Services, Inc.
Quahty Results troen Quahty People REF: GEN 9112-089 December 31,1992 Mr. Carl H. Clement Unit Director, Millstone Unit 3 Northeast Utilities P.O. Box 128 Waterford, Connecticut 06385
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuar t to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seats as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this tranped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR.
pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
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5 5
i 75 Glen Roac Sandy Hook, CT 06432 (203)426 9239 Fax (203) 426-9629 h
i b
BRAND 2-Mr. Carl H. Clement REF: GEN 9112-089 Unit Director, Millstone Unit 3 December 31,1992 BUSI has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
\\LL[d John R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
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l E3 RAND arand utmty sermcet. inc.
Quahty Results from Quahty People REF: GEN 9112 090 December 31,1992 Mr. Gerald B. Slade Plant General Manager, Palisades Consumers Power Co.
27780 Blue Star Highway Covert, Michigan 49043
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUS 1) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSI to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam ge 1erators in order to perform maintenance activities while the reactor is being refaled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism majhcreate a trapped air column behind the cold leg nozzle dam. This air column coud be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. -This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUS 1, previously sold as Busitech: Nuclear Energy Services; and Cornbustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations, j
i F
1 5
I 75 GMn Road Sandy Hock. CT 06432 (2031426 9239 Fax (203) 426 9829 h
BRANO Mr. Gerald B. Slade REF: GEN 9112-090 Plant General Manager, Palisades December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, (k
N w
ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRAllm encl.
cc:
US Nuclear Regulatory Commission l
l
e BRAND Brano utnisty Services,Inc.
Quality Results from Quahty Pecpte REF: GEN 9112 091 December 31,1992 Mr. William E. Ide Plant Manager, Palo Verde 1 Arizona Public Service Co.
P.O. Box 52034 Phoenix, Arizona 85072
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSl) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water), Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during.mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSI, previously sold as Busitech: Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations, j
I 75 G!en Road Sandy Hook, Cr 06482 (203)426 9239 Fax (203) 426-9829 h
8 RAND 2-Mr. William E. Ido REF: GEN 9112-091 Plant Manager, Palo Verde 1 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR coolin0 For further information, please contact the undersigned.
Very truly yours, lV hohn R. Allanach General Mana0er Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
If f
BRAND Brand Uttisty sermces. Inc.
Quality Results from Quan:y People REF: GEN 9112-092 December 31,1992' Mr. Ronald K. Flood Plant Manager, Palo Verde 2 Arizona Public Service Co.
P.O. Box 52034 Phoenix, Arizona 85072
Subject:
Potential Loss of RHR CoolinD During Nozzle Dam Removal Gentlemen:
- The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal coolin0 durin0 the removal of steam generator nozzle dams, This information is bein0 provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealin0 mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refuelin0 pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Havin0 an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle riam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary scaling mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
j 1
i 75 Glen Road Sandy Hook CT 06432 (203)426-9239 Fax (203) 426 9829 h
1 BRAND 2
Mr. Ronald K. Flood REF: GEN 9112-092 Plant Manager, Palo Verde 2 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
' {._ k 0 4 ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
g BRAND erand Utlfsty Sermces. Inc.
Quahty Results from Quality People REF: GEN 9112-093 December 31,1992 Mr. Robert J. Adney Plant Manager, Palo Verde 3 Arizona Public Service Co.
P.O. Box 52034 Phoenix, Arizona 85072
Subject:
Potential Loss of RHR Cooling During Nozzle Darn Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzie dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically _ pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period _ Having an -
air colum'n in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR
- pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSI, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above cc.1cerns relative to use of nozzle dams during refueling operations.
j i
I-i I
75 Gien Road Sandy Heck, CT 06482 (203)426-9239 Fax (203) 426-9329 h
l
P BRAND 2-Mr. Robert J. Adney REF: GEN 9112-093 Plant Manager, Palo Verde 3 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours,
,kJ
)
~--
C ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRAllm encl.
cc:
US Nuclear Regulatory Commission ppm
BRAND erano utiinty services,inc.
ouaiay sesuits from oual,ty Pecole REF: GEN 9112-094 December 31,1992 Mr. H. E. Morgan Vice President & Site Manager, San Onofre 1,2 & 3 Southern California Edison Co.
P.O. Box 128 San Clemente, California 92674-0128
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cojd leg nozzle dam, This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition wsuld cause loss of RHR cooling during mid-loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech: Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
)
i i
i; h
n cien noaa sano sccm cr ceasa coai4:e+239 Fax <203)42e se29 v
8 RAND Mr. H. E. Morgan REF: GEN 9112-094 Vice President & Site Manager, December 31,1992 San Onofre 1,2 & 3 BUSl has developed a modification to existing nozzle dams and plant p'ocedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersi ned.
0 Very truly yours, ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
ec:
US Nuclear Regulatory Commission
4 e
e BRAND Brand utmty semces, Inc.
Quahty Results from Quahty People REF: GEN 9112-095 December 31,1992 Mr. G. J. Boissy Plant Manager, St. Lucie 1 & 2 Florida Power & Li ht Co.
0 P.O. Box 128 Fort Pierce, Florida 33454
Subject:
Potential Loss of RHR Cooling During Nozzio Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
Durin0 refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealin0 mechanism may create a trapped air column behind the cold leg nozzle dam. This air _ column could be created by undetectable minute leaks of air through the inflatable seals-which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold le0 would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would relt e this trapped air column and could cause the RCS inventory to suddenly o :rease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSI is recommending to all users of nozzio dams that utilize inflatable seals as the primary sealing mechanisms (BUSI, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
-j i
s ii 1
75 Glen Road Sandy Hook, CT 06482 (203)426-9239 Fan (203) 426-9829 h
8 RAND I
2-Mr. G. J. Boissy REF: GEN 9112-095 Plant Mana0er, St. Lucio 1 & 2 December 31,1992 BUSl has developed a modification to existin0 nozzle dams and plant procedures that would prevent the above described potentialloss of RHR coolin0. For further information, please contact the undersigned.
Very truly yours, Ulbl
,/ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
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BRAND Urand Utsty servsces. tnc.
Cuahty Results from Quahty Poople REF: GEN 9112-096 December 31,1992 Mr. Dan Packer General Manager, Waterford 3 Entergy Operations, lac.
P.O. Box B Highway 18 Killona, Loulslana 70066
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg-would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this-trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSlis unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms -
(BUSl, previously sold as Busitech: Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during j
refueling operations, j
1 s
!x 75 GWn Road Sandy Hook. CT e6482 (2e3) 426-9239 Fax (203) 426-9829 -
h
BRAND Mr. Dan Packer REF: GEN 9112-096 General Manager, Waterford 3 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours f
lb ohn R. Allanach
' General Manager Engineered Products Division Brand Utility Services, Inc, JRA/Im enci.
cc:
US Nuclear Regulatory Commission l
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BRAND Brand UtiMy Services,Inc.
Quabfy Sesults from Quahry r+orte REF: GEN 9212-097 December 31,1992 Mr. John D. Blosser Manager, Callaway Plant Union Electric Co.
P.O. Box 620 Fulton, Missouri 65251
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gontlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal coolin0 durin0 the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the ' cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals d
which are typically pressurized.to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of'the cold leg leadin0 to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling durin0 mid loop conditions. Removal of the cold 100 nozzle dem would release this trapped air column and could cause the RCS inventory to suddenly decrease to a
' level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooiing during mid-loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilize inflatable seats as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations, j
i I
i 75 Glen Rcad Sandy Hook. CT OM82 (2e3) 42fr9239 Fax (203)426 9829 b
I
_ BRAND Mr. John D. Blosser REF: GEN 9112 097 Manager, Callaway Plant December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further inforrnation, please contact the undersigned.
Very truly yours, LtL0LS j ohn R. Allanach General Manager En0ineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
k
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.o BRAND Drund ut6hty services,inc.
Quahty Results from Quality People REF: GEN 9112-098 December 31,1992 Mr. J. J. Kelley, Jr.
Plant Manager, Comancl.e Peak 1 & 2 TU Electric P.O. Box 1002 Glen Rose, Texas 76043
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals-which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
j i
i 75 Glen Road Sanay Hook CT 06482 (203)426-9239 Fax (203) 426-9829 h
I
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BRAND Mr. J. J. Kelley, Jr.
REF: GEN 9112-098 Plant Manager, Comanche Peak 1 & 2 December 31,1992 BUSI has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, b
b ohn R. Allanach y
General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
J BRAND Brand utshty services.1nc.
Quality Results from Ouality People REF: GEN 9112-099 December 31,1992 Mr. A. A. Blind Plant Manager, D.C. Cook 1 & 2 Indiana / Michigan Power Co.
One Cook Place Bridgman, Michigan 49106
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSI to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the !nflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSI, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
j 1
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75 G!cn Road Sandy Hook. CT 06482 (203)426-9239 Fax (203) 426-9829 h
BRAND Mr. A. A. Blind REF: GEN 9112-099-Plant Manager, D.C. Cook 1 & 2 December 31,1992 BUSI has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, 944M
/
hohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission
e BRAND erand uts;ity services, Inc.
Quality Results from Quality People REF: GEN 9112-100 December 31,1992 Mr. Joseph A. Widay Plant Manager, Ginna Station Rochester Gas and Electric Corp, 1503 Lake Road Ontario, New York 14519
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21,21(b) which requires BUSI to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealing mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period Having an air column in place of water means there is less water available for cooling during mid loop conditions, Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortextrg/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations, j
l 4:
?
75 Gien Acad Sandy Hock, CT 06482 (203)426 9239 Fax (203) 426 9829 h
4 BRAND 2-Mr. Joseph A. Widay REF: GEN 9112-100 Plant Manager, Ginna Station December 31,1992 BUSl has develope'd a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling For further information, please contact the undersigned, Very truly your, -
{
ohn R, Allanach General Manager Engineered Products Division Brand Utility Services, Inc, JRA/Im encl.
cc:
US Nuclear Regulatory Commission
i BRAND l
Drand utikty Services,Inc.
Cuahty Nesults from Ovahty Peop/c i
REF: GEN 9212101 December 31,1992 Mr. Mark L. Marchi Plant Manager, Kowauneo Wisconsin Public Service Corporation North 490, Highway 42 Kowauneo, Wisconsin 54216 9510
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling during the removal of steam generator nozzlo dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform offected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzio dams are commonly used to isolato the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzlo dams that utilize inflatable seals as the primary scaling mechanism may croato a trapped air column behind the cold 100 nozzle dam. This air column could be created by undetectable rninuto leaks of air through the inflatablo seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This ovacuation of water could occur within a savon day period. Having an air co!umn in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzlo dam would release this trapped air column and could cause the RCS Inventory ?o suddenly decrease to a level below the RHR suction lino causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determino if this potential condition would cause loss of RHR cooling during mid loop operations in your plant. BUSI is recommending to all"sers of nozzlo dams that utilizo inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitoch; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relativo to use of nozzle dams during refueling operations, j
k
- I i
75 Glen Road Sandy Hook. CT 06482 (203)426 9239 Fax (203) 426 9a29 h
8 RAND 2
Mr. Mark L Marchi REF: GEN 9212101 Plant Managor, Kowaunoo December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersl0 nod.
Very truly yours,
_ ff
'k John R. Atlanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im
- encl, cc:
US Nuclear Regulatory Commission
4 BRANE5
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urano uswsy semen, snc.
ovanty nesuns nom cuouy nwe REF: GEN 9212102 December 31,1992 Mr. Gre0ory J. Maxfield Mana0er, Nuclear Operations Point Beach 1 & 2 Wisconsin Electric Power Co.
6610 Nuclear Road Twr P'
. Wisconsin 54241 St Potential Loss of RHR Cooling During Nozzlo Dam Removal Ge The purpass of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam generator nozzle dams. This information is bcIng provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzlo dams are commonly used to isolate the steam Donerators in order to perform maintenance activities while the reactor is bein0 refueled. Nozzle dams that utilize inflatablo seals as the primary sealing mechanism may create a trapped air column behind the cold 100 nozzle dam. This air column could be created by undetectablo minuto leaks of air through the inflatablo seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool wator). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold 100 eading to the RCS l
pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold log nozzlo dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR coolin0-BUSl is unable to determino if this potential condition would cause loss of RHR coolin0 durin0 mid-loop operations in your plant, BUSl is recommendin0 to all users of nozzle dams that utilize inflatab!o seals as the primary sealing mechanisms (BUSI, previously sold as Busitoch; Nuclear Energy Services; and Combustion Engineering) t3 review the above concerns relative to use of nozzle dams during refueling operations.
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75 Glen nead Sandy Hook, CT 06482 (2031426-9239 Fax (203) 426-9829.
b m
8FRAND 2
Mr. Gregory J. Maxfield REF: GEN 9212-102 Mana0er, Nuclear Operations -
December 31,1992 Point Beach 1 & 2 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, pleast contact the undersl ned.
0 Very truly yours,
[
N john R. Allanoch General Manager En0 neered Products Division l
Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission i
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E3 RAND orano utinty serwces. inc.
ovay nesons tre,n ovaw rwe REF: GEN 9212103 December 31,1992 Mr. Mike Sellman Plant Manager, Prairie Island 1 & 2 Northem States Power Co.
1717 Wakonado Drive East (Route 2)
Welch, Minnesota 55089
Subject:
Potentialloss of RHR CoolinD Durin0 Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSl) has identified a potentialissue related to residual heat removal coolin0 durin0 the removal of steam generator nozzle dams. This information is bein0 provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
Durin0 refuelin0 activities, nonic dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary sealinD mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air throu0h the inflatable seals
~
which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refuelin0 pool water). Continual leaka00 of air into the cold 100 would eventually evacuate the vertical portion of the cold 100 eading to the RCS l
pump. This evacuation of water could occur within a seven day period Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the cold leg nozzio dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causin0 a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR coolin0-BUSl is unable to determine if this potential condition would cause loss of RHR coolin0 durin0 mid-loop operations in your plant. BUSI is recommendin0 to all users of nozzle dams that utilize inflatable seals as the primary scalin0 mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineerin0) to review the above concerns relative to use of nnzzle dams during refuelin0 operations.
}i w
1 4I 75 Gien Road Sandy Hed, CT 06482 (203)426 9z39 Fa x (203) 4 26-9829 h
BRAND 2-Mr. Mike Sellman REF: GEN 9212103 Plant Manager, Prairic Island 1 & 2 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potential loss of RHR cooling. For further information, please contact the undersl ned.
0 Very truly yours, UU2sA J hn R. Allanach "Donoral Mana0er EnDineered Products Division Brand Utility Services, Inc, JRA/Im encl.
cc:
US Nuclear Regulatory Comrnission
. - - - _ - = ~ _
M e'
l BRAND Utend Utahty SerMces,inc.
Quakty Results from QuaMy Peoole REF: GEN 9212104 December 31,1992 Mr. Calvin Vondra General Manager, Salem Operations Public Service Electric & Gas Co.
P.O. Box 236 Hancocks Bridge, Now Jersey 08038
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemon:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issuo related to residual heat removal coolin0 during the removal of steam Generator nozzio dams. This information is bein0 provided to you under the requirements delinoated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refuelin0 activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary scaling mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minuto leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleaka00 of air into the cold leg would eventually evacuate the vertical portion of the cold leg leadin0 to the RCS pump. This evacuation of water could occur within a seven day period. Having an air column in place of water means there is less water available for cooling during mid loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causing a risk of vortexing/ cavitation of the RHR pumps arid subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling durin0 mid loop operations in your plant. - BUSI is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refueling operations.
j l
ri l
i
' 75 Glen Road Sandy Hook, CT C64S2 (203) 426-9233 Fax (203) 426-9829 h
8 RAND 2-Mr. Calvin Vondra REF: GEN 9212-104 General Mana0er, Salem Operations December 31,1992 BUSl has developed a rnodification to existin0 nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersl ned.
0 Very truly yours,
%Lk 06 J hn R. Allanach General Mana0er En0 neered Products Division i
Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Re0ulatory Commission
e V
BRAND erano utaay somcas. inc.
ovaw smuas fem cuaor we r
l REF: GEN 9212105 December 31,1992 Mr. R. J. Beecken Plant Mana0er, Sequoyah 1 & 2 Tennessee Valley Authority P.O. Box 2000 Soddy-Daisy, Tennessee 37379
Subject:
Potential Loss of RHR Cooling During Nozzle Dam Removal Gentlemem The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSl) has identified a potentialissue related to residual heat removal cooling during the removal of steam Generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(ab During refuelin0 activities, nozzle dams are commonly used to isolato the steam generators in order to perform maintenance activities while the reactor is bein0 refueled. Nozzle dams that utilize inflatable seals as the primary sealin0 mechanism may create a trapped air column behind the cold 100 nozzlo dam. This air column could be created by undetectable minuto leaks of air throu0h the inflatable seals which are typically pressurized to 65 psi 0 (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leakage of air into the cold 100 would eventually evacuate the vertical portion of the cold 109 eading to the RCS l
pump. This evacuation of water could occur within a seven day porlod. Havin0 an air column in place of water means there is less water available for coolin0 durin0 mid-loop conditions. Removal of the cold le0 nozzio dam woulo release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexin0/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid loop operations in ycur plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealin0 mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzlo dams during ref ueling operations.
}l i
M G6M Sandy Hh CMMM CNM93 fn COME9 h
.f BRAND 2-Mr. R. J. Boeckon REF: GEN 9212-105 Plant Mana0er, Sequoyah 1 & 2 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant proceduros that would provent the above described potentialloss of RHR cooling. For further information, please contact the undersl ned.
0 Very truly yours,
,U b
{ General Manager ohn R. Allanach Engincored Products Division Brand Utility Services, Inc.
JRA/Im oncl.
cc:
US Nuclear Ro0ulatory Commission l
l l
i
e E3 RAND Urand u1lHty berv ces, anc, Quahty Results trorn Quaisty Fwple REF: GEN 9212106 December 31,1992 Mr. C. S. Hinnant Gonoral Mana0er, Harris Plant Carolina Power & Light Co.
P.O. Box 165 Now Hill, North Carolina 27502
Subject:
Potentialloss of RHR CoolinD Durin0 Nozzlo Dam Removal Gentlemen:
The purpose of this lotter is to inform you that Brand Utility Services, Inc. (BUSI) has identiflod a potential issun related to residual heat removal cooling during the removal of steam generator nozzlo dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to Inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzlo dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refuelod. Nozzio dams that utilizo inflatable seals as the primary sealing mechanism may creato a trapped air column behind the cold log nozzle dam. This air column could be created by undetectable minuto looks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refuelin0 pool water). Continualleakage of air into the cold 100 would eventually evacuato the vertical portion of the cold 100 leading to the RCS pump. This ovacuation of water could occur within a sovon day period. Having an air column in place of water means thero is loss water available for coolinD durin0 mid loop conditions. Removal of the cold log no;;zlo dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction lino causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR coolin0 BUSl is unable to determino if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSI is recommending to all users of nozzlo dams that utilize inflatable seats as the primary sealing mechanisms (BUSl, previously sold as Busitoch; Nuclear Ener0y Services; and Combustion EnD ncering) to review the above concerns relative to use of nozzio dams during i
refuelin0 operations, j
I s.
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75 Gion Road Sandy HxA, CT e6482 (203)426 9239 Fax (203) 42649829 -
h.
0 8RANO 2-Mr. C. S. Hinnant REF: GEN 9212-106 General Manager, Harris Plant December 3),1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, I
ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Re0ulatory Commission
I e
E3 RAND Urand utsuty sermces, inc.
QuMt/ Results l'Om OvMty Pv00le REF: GEN 9212107 December 31,1992 Mr. M. R. Wisenburg Plant Manager, STP Unit 1 & 2 Houston Ll hting & Power Co.
0 P.O. Box 289 Wadsworth, Texas 77483
Subject:
Potential Loss of RHR CoolinD DurinD Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potential issue related to residual heat removal cooling during the removal of steam genc ator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary scaling mechanism may create a trapped air column behind the cold log nozzle dam. This air column could be created by undetectable minute leaks of air throu0h the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold leg would eventually evacuate the vertical portion of the cold leg leading to the RCS pump. This evacuation of water could occur within a seven day period. Havin0 an air column in place of water means there is less water available for coolin0 during mid-loop conditions. Removal of the cold leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSI is unable to determine if this potential condition would cause loss of RHR cooling durin0 mid-loop operations in your plant. BUSI is recommendin0 to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech; Nuclear Energy Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refuelin0 operations, j
i s
i i
75 Glen Road Sandy Hook. CT c6482 (2e31426-9239 Fax (203) 426-9829 h
l E3 RAND 2-Mr. M. R. Wisenburg REF: GEN 9212-107 Plant Manager, STP Unit 1 & 2 December 31,1992 BUSl has developed a modification to existinD nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact thu undersigned.
Very truly yourr
(
I
' ifL u
/
b ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission I
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BRAND Uf and Utdatf setVtC09,lnC.
Qual,fy ResuM5 from Qudh(y PeopW REF: GEN 9212108 December 31,1992 Mr. William R. Robinson General Managor Trojan Plant Portland Gonoral Electric Co.
71700 Columbia River Hl hway 0
Rainier, Or000n 97048
Subject:
Potential Loss of RHR Cooling Durin0 Nozzlo Dam Removal Gentlemen:
The purpose of this lotter is to inform you that Brand Utility Services, Inc. (BUSl) has identiflod a potentialissuo related to residual heat removal cooling durin0 the removal of steam Donorator nozzio dams. This information is bein0 provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situatloa such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refuelin0 activities, nozzlo dams are commonly used to isolate the steam Generators in order to perform maintenance activities while the reactor is being refooled. Nozzio dams that utilize inflatable seals as the primary sealing mechanism may creato a trapped air column behind the cold log nozzle dam. This air column could be created by undetectable minuto leaks of air through the Inflatable seals which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refuelin0 pool water). Continual leakago of air into the cold 100 would eventually evacuate the vertical portion of the cold 100 loading to the RCS pump. This evacuation of water could occur within a savon day period. Having an air column in place of water means there is less water availablo for cooling during mid-loop conditions. Removal of the cold tog nozzlo dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a lovel below the RHR suction lino causin0 a risk of vortexin0/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR coolin0 during mid loop operations in your plant. BUSI is recommending to all users of nozzio dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitoch: Nuclear Ener0y Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during refuelin0 operations, j
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i 75 Glen Road Sandy Hook CT 00482 (203)426 9239 Fax (203) 426 9829 h
8 RAND 2
Mr. Williarn R. Robinson REF: GEN 9212108 General Mana0er, Trojan Plant December 31,1992 BUSI has developed a modification to existin0 nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersigned.
Very truly yours, kh.
A John R. Allanach General Manager i
EnD neered Products Division Brand Utility Services, Inc.
JRAllm oncl.
cc:
US Nuclear Re0ulatory Commission i
.M BRAND orana uimty semees inc.
ovaw nesuns nom ovauf reens REF: GEN 9212-109 December 31,1992 Mr. J. L. Skolds Vice President, Nuclear Operations - V. C. Summer South Carolina Electric & Gas Co.
P.O. Box 88 Jenkinsville, South Carolina 29065
Subject:
Potential Loss of RHR Cooling Durin0 Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal coolin0 during the removal of steam generator nozzle dams. This information is bein0 provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSI to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
Durin0 refuelin0 activities, nozzle dams are commonly used to isolate the steam Generators in order to perform maintenance activities while the reactor is bein0 refueled. Nozzle dams that utilize inflatable seals as the primary sealin0 mechanism may create a trapped air column behind the cold leg nozzle dam. This alt column could be created by undetectable minute leaks of air through the inflatable seals which are typically pressurized to 65 psl0 (almost 5 times the hydrostatic pressure caused by the refuelin0 pool water). Continual leakage of air into the cold 100 would eventually evacuate the vertical portion of the cold le0 eadin0 to the RCS l
pump. This evacuation of water could occur within a seven day period. Havin0 an air column in place of water means there is less water available for cooling during mid loop conditions. Removal of the cold 100 nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR coolin0 BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid-loop operations in your plant. BUSI is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms (BUSl, previously sold as Busitech: Nuclear Energy Services; and Combustion Engineerin0) to review the above concerns relative to use of nozzle dams during refuelin0 operations.
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i 1
75 Glen Read Sandy HocN CT 06482 (203)426 9239 Fax (203) 406 9929 h
f BRANO 2-Mr. J. L. Skolds REF: GEN 9212109 Vice President, Nuclear Operations December 31,1992 V. C. Surnmer BUSl has developeJ a rnodification to exletino nozzle dams and plant procedures that would prevent the above described potentialloss of RHR coolina, For further information, please contact the undersl ned.
0 Very truly yours,
$f. b
)hn R. Allanach General Monager En0 neered Products Division l
Brand Utility Services, Inc.
JRA/Im
- encl, cc:
US Nuclear Regulatory Commission
BRAND Urand Utsisty Serwces. Inc, Quality Results fic.n Quality PWole REF: GEN 9212-110 December 31,1992 Mr. William B. Shipman General Mana0er, Vogtle 1 & 2 Georgia Power Co.
P.O. Box 1600 Waynesboro, Geor0 a 30830 l
Subject:
Potential Loss of RHR Cooling During Nozzlo Dam Removal Gentlemon:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identilled a potentialissue related to residual heat removal coolin0 durin0 the removal of steam 00norator.nozzlo dams. This information is being provided to you under the requiroments delineated in 10CFR21.21(b) which requi os BUSl to inform affected customers of this potential situation such that licensees may ovaluato the situation pursuant to 10CFR21.21(a).
During refuelin0 activities, nozzle dams are commonly used to isolate the steam generators in order to perform maintenanco activities while the reactor is being refueled. Notzle dams that utilize inflatable seals as the primary sealin0 mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minuto leaks of air through the inflatable seals which are typically pressurized to 65 psig (almost 5 timos the hydrostatic pressure caused by the refueling pool water). Continualleakage of air into the cold log would eventually ovacuate the vertical portion of the cold log loading to the RCS pump. This evacuation of water could occur within a sovon day period. Havin0 an air column in place of water means there is less water available for cooling durin0 mid loop conditions. Removal of the cold 1e0 nozzlo dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a lovel below the RHR suction lino causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to datormino if this potential condition would cause loss of RHR coolin0 durin0 mid-loop operations in your plant. BUSl is recommending to all users L
of nozzle dams that utilizo inflatable seals as the primary sealing mechanisms (BUSI, previously sold as Busitech; Nuclear Enor0y Services; and Combustion Engineering) to review the above concerns relative to use of nozzle dams during
[
refueling operations.
)i i
75 Glen Road Sandy Hece. cT e6482 (203)426-9239 Fax (203) 426 9829 h
a
E3 RAND 2-Mr. William B. Shipman REF: GEN 9212110 General Manager, Vogtle 1 & 2 December 31,1992 BUSl has developed a modification to existing nozzle dams and plant procedures that would prevent the above described potentialloss of RHR cooling. For further information, please contact the undersl ned.
0 Very truly yours,
$1 ohn R. Allanach General Manager Engineered Products Division Brand Utility Services, Inc.
JRA/Im encl.
cc:
US Nuclear Regulatory Commission i
o i
e BRAND erano utshty Sermces. Inc.
Cutty Results from Quahty Peacle REF: GEN 9212-111 December 31,1992 Mr. Otto Maynard Plant Manager, Wolf Creek Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlin0 ton, Kansas 66839
Subject:
Potentialloss of RHR Cooling Durin0 Nozzle Dam Removal Gentlemen:
The purpose of this letter is to inform you that Brand Utility Services, Inc. (BUSI) has identified a potentialissue related to residual heat removal cooling during the removal of stoom generator nozzle dams. This information is being provided to you under the requirements delineated in 10CFR21.21(b) which requires BUSl to inform affected customers of this potential situation such that licensees may evaluate the situation pursuant to 10CFR21.21(a).
During refueling activities, nozzle dams are commonly used to isolata the steam generators in order to perform maintenance activities while the reactor is being refueled. Nozzle dams that utilize inflatable seals as the primary scalin0 mechanism may create a trapped air column behind the cold leg nozzle dam. This air column could be created by undetectable minute leaks of air throu0h the inflatable seals which are typically pressurized to 65 psig (almost 5 times the hydrostatic pressure caused by the refueling pool water). Continual leaka00 of air into the cold log would eventually evacuate the vertical portion of the cold 100 eading to the RCS l
pump. This evacuation of water could occur within a'seven day period. Having an air column in place of water means there is less water available for cooling during mid-loop conditions. Removal of the colti leg nozzle dam would release this trapped air column and could cause the RCS inventory to suddenly decrease to a level below the RHR suction line causing a risk of vortexing/ cavitation of the RHR pumps and subsequent loss of RHR cooling.
BUSl is unable to determine if this potential condition would cause loss of RHR cooling during mid loop operations in your plant. BUSl is recommending to all users of nozzle dams that utilize inflatable seals as the primary sealing mechanisms:
(BUSl, previously sold as Busitech: Nuclear Energy Services; and Combustion l
Engineerin0) to review the above concerns relative to use of nozzle dams during refueling operations, j-1 5
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75 Glen Road Sandy Hook, CT o6480 (203)426-9239 Fax (203)426 9829
.o
_ BRAND 2
Mr. Otto Maynard REF: GEN 9212111 Plant Manager, Wolf Crook December 31,1992 BUSl has developed a modification to existing nozzlo dams and plant proceduros that would provent the above described potentialloss of RHR coolin0. For further information, please contact the undersigned.
Very truly yours,
[f b
(John R. Allanach General Mana0er EnD neered Products Division i
Brand Utility Services, Inc.
JRA/Im oncl.
cc:
US Nuclear Regulatory Commission i
.: