ML19255E722
| ML19255E722 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 11/02/1982 |
| From: | Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT |
| To: | Check P Office of Nuclear Reactor Regulation |
| References | |
| HQ:S:82:119, NUDOCS 8211060124 | |
| Download: ML19255E722 (58) | |
Text
{{#Wiki_filter:h @2 Department of Energy Washington, D.C. 20545 Docket No. 50-537 HQ:S:82:119 NOV 0 21982 Mr. Paul S. Check, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Mr. Check:
ELECTRICAL POWER WORKING MEETING, OCTOBER 19, 1982 - ADDITIONAL INFORMATION
Reference:
Longenecker to Check,
Subject:
Meeting Sumiiary for the Electrical Power '.dorking Meeting, October 19, 1982, dated October 19, 1982 Enclosed is the additional information requested during the subject meeting for which response dates of November 2,1982, were projected. Marked up Preliminary Safety Analysis Report (PSAR) pages will be incorporated ir.to a future PSAR revision. Additional information regarding item 8.3.3.3.g will be provided December 1, 1982. Any questions regarding the information provided or further activities can be addressed to Messers. J. Krass (FTS 626-6163), D. Hicks (FTS 626-6150) or A. Meller (FTS 626-6355) of the Project Office Oak Ridge staff. Sincerely, hu, pfSool lb JokinR.Longene er Acting Director, Office of the Clinch River Breeder Reactor Plant Project Office of Nuclear Energy Enclosure cc: Service List O Standard Distribution Licensing Distribution 8211060124 821102 CF ADDCK 05000537 CF
RESPONSES TO ITEMS FROM THE OCTOBER 19, 1982 ELECTRICAL POWER 5 WORKING MEETING g l ~ t t:. 4 1 -e 8.2.2.1 - Physical / Independence of of fsite circuits 2 - 8.2.2 - Availability of of fsite power within sufficient time 3 - 8.2.2.3 - Load Sequencing 4 - 8.2.2.4 - Fault Sensing Relays / Availability of offsite Power Source 5 - 8.2.2.5 - Surveillance of Offsite Power Supplies 6 - 8.2.3.1 - Testing of Transfer Capability 7 - 8.3.1.1 - Division 1 and 2 Interconnection versus Gnc 17 8 - 8.3-.2 - Suitable Electrical Interconnection 9 - 8.3.1.3 - Redundancy of Three Independent Load Groups 10 - 8.3.1.4 - Non-Class lE Loads Powered from Class IE Systems a) Failure modes of Class lE breaker b) Non-Class IE load failures 11 - 8.3.3.1.1 - Environmental Qualification of Cables and Terminations 12 - 8.3.3.3 - Independence-(Compliance with GDC 17) a) Physical / Independence c) Pipe Break
- e)
Associated Circuit (Additional information will be provided by December 1, 1982) a e
' g) Physical separation of Class lE equipment I Er h) Conduits as' Fire Barriers S i) Protection of Class lE Cables from Rotating or Dropped Equipment 13 - 8.3.3.5.1 - Testing of Circuit Breaker 14 - 8.3.3.4 - TMI Action Plan Requirements E I
8.2.2.i NRC COMMENT s Physical Independence of Offsite Circuits g ':9 ThefClinch River PSAR does not adequately describe or afalyze phys 3calindependenceofoffsitecircuits. The applicar$t by Letter dated June 1, 1982 has stated that the two offsite cir-cuits that pass through the reserve switchyard provide the two physically independent offsite power sources. The PSAR, in contradiction, implies that the offsite circuits that pass through the generating switchyard are immediate access circuits and, thus, the preferred offsite circuit as defined by IEEE Standard 308-1974. It is the staff position, in accordance with the requirements of GDC 17, that el~ectric power from the trans-mission network to the onsite electric distribution system shall be supplied by two physically independent circuits designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. The description and analysis required to demonstrate compliance with the above position will be pursued with the applicant and the results of the staff. evaluation will be reported in a supplement to this report.
RESPONSE
The CRBRP will be connected to the TVA 161KV grid using four separate connections between the switchyards and the TVA grid as described in Section 8.1 of the PSAR. All four transmission lines are kept continuously energized. The CRBRP design includes two physically separate and electrically independent switchyards, generating swit_chyard and reserve switchyard. Each of these two switchyards is connected to the TVA grid by two separate 161KV transmission lines. The two connections to the reserve switchyard from the Oak switchyardofDOEfdesignated Ridge Gaseous Diffusion Plant (ORGDP) as the K-31 line and the other to the Fort Loudoun Hydroelectric 8.2.2.1-1
8.*2.2.1 (continued) Plant, designated as Fort Loudoun-2 line, are considered the two physically independent and immediate access circuits. The se circuitsarelocatedsoastominimizethelikelihoodhoftheir sfmultaneous f ailure under operating and postulated abcident and ebvironmental conditions. The physical separation of the four (4) transmission line connections from the TVA 161EV grid to the CRBRP switchyards is shown in Figure 8.2-12. 7he K-31 transmission line connection crosses over the two connections (Roane and Fort Loudoun 1) to the Generating switchyard. As such, failure of any of the two 161KV line connections to the Generating switchyard will not result in failure of the K-31 or Fort Loudoun-2 lines. Further, between the CRBRP and the destination substations (K-31 and Fort Loudoun-2): 1. at any one location no transmission line crosses over the two transmission lines to the :_eserve Suitchyard simultaneously; 2. transmission lines are spaced sufficiently apart such that failure of one line does not affect the other line. The 4.16KV medium voltage (MV) winding of the Reserve Station Service Transformer (RSST) llAAX005A will be connected to the Medium Voltage switchgear of Class 1E, Division 1 through a non-segregated phase bus duct.and to the Medium Voltage Switchgear of Class lE, Division 3 through a non-segregated phase bus duct and MV cables. The 4.16KV MV winding of the RSST 11AAX005B will be connected to the Medium Voltage ~ Switchgear of Class lE Division 2 through non-segrega,ted phase bus duct. Similarly, the 4.16KV windings of the Uni Station 8.2.2.1-2
s Service Transformers (USSTs) llAAX006A and B are also connected 5-30 theClasslE,. Division 1,2and3MediumVoltagejswitchgear 1: (through non-segregated phase bus ducts. Non-segregated bus ducts from the RSSTs llAAX005A and B and USSTs llAAX000A and B to the Medium Voltage Switchgear of Class lE, Divisions 1, 2 and 3 will be physically separated such that failure of any one bus duct will minimize the tikelihood of failure of the other bus ducts. The response to question CS430.1 will be revised as attached to include the above description. s a 8.2.2.1-3 b
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' WE2-0200,0,22; 42 pe;? Ouertlen CS230.1 (8.2) 9 h Pro 23de physical layout. drawings end/or edditional description in the PSAR of thelphysical Independence to be provided between the of f site power (,Ircuits in pronimity of the plent to the switchyards and from the switchyard to the Class IE dhsite power system. Also provide description of physical independence between Class 1E and the of f site circuits protective releying. Bernense K-31 and Fort Loudoun-2161kV transmission lines (both cor.nected to the reserve switchyard of the CRBRP) provide the two physically independent of f site power sources to CRBRP; details of their routing and construction in the proximity of the plant have been described in Section 8.2.1.1 and 8.2.1.3 CT?: of the PSAR. " P c, ?, t:,. r 4.iiy v. u.c 1. et any one locetion no transm sion line crosses over these two transmission lines simultane asly; 2. transmission lines are sp ed sufficiently epert such that failure of one line does not effect the other line. (see Figures 8.2-11 end 8.2-12 etteched). This demonstrates the physt i Independence of the two of f site power sources. 4,/ The 4.16kV medium voltag (MV) winding of the Reserve Stetton Service Trensformer (RSST) 11AA 05A will be conected to the Medium Voltage Switchgeer through a non-segregated phase bus duct and to the of Class 1E Division Medium voltage Swlte geer of Class 1E Division 3, through the non-segregeted. phase bus duct and .V cables. Similerly, the 4.16kV MV winding of the RSST 11AAX005B Is con eted to the Class 1E Division 2 switchgeer through non-segregated ese bus duct. Non-segrege+ d phase bus duct runs from RSSTs 11AAX005A end 58 ere physically separated Control end protection circuits for the Reserve Switchyard have been errenged to receive 125V DC power from two Independent Divisions A and B DC power distribution systems (see Figure 8.2-13). The DC equipnent of the two divisions are physically seperate and electrically independent of each other. The control cables of Divisions A and B are routed in separate trays and conduits. a m QCS430.1-1 7_ C OS
k ItiSERT 1 Y I i {7 The CRBRP will be connected to the TVA 161KV grid using four~ separate connections between the switchyards and the TVA grid as described in Section 8.1 of the PSAR. All four transmission lines are kept continously energized. The CRBRP design includes two physically separate and electrically independent switchyards, generating switchyard and reserve switchyard. Each of these two switchyards is connected to the TVA grid by two separate 161KV transmission lines. The two connections to the reserve switchyard from the Oak Ridge Gaseous Diffusion Plant (ORGDP) switchyard of DOE, designated as the K-31 line and the other to the Fort Loudoun Hydroelectric Plant, designated as Fort Loudoun-2 line, are considered the two physically independent and irrnediate access circuits. These circuits are located so as to minimize the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. The physical separation of the four (4) transmission line connections from the TVA 161KV grid to the CRBRP switchyards is shown in Figure 8.2-12. The K-31 transmission line connection crosses over the two connections (Roane and Fort Loudoun 1) to the Generating switchyard. As such, failure of any of the two 161XV line connections to the Generating switchyard will not result in failure of the K-31 or Fort Loudoun-2 lines. Further, between the CRBRP and the destination substations (K-31 and Fort Loudoun 2): 1. at any one location no transmission line crosses over the two transmission lines to the Reserve w Switchyard simultaneously; ? 2. transmission lines are spaced sufficiently apart I such that failure of one line does not affect the other line. (See Figures 8.2-11 and 8.2-12).
I 1: J. INSERT 1 (continued) [ 5 I The 4.16KV medium voltage (MV) winding of the Reserve Station Service Transformer (RSST) 11AAX005A will be connected to the Medium Voltage switchgear of Class IE, Division I through a non-segregeted phase bus duct and to the Medium Voltage Switchgear of Class IE, Divison 3 through a non-segregated phase bus duct and MV cables. The 4.16KV MV winding of the RSST 11AAX005B will be connected to the Medium Voltage Switchgear of Class IE Division 2 through non-segregated phase bus duct. Similarly, the 4.16KV windings of the Unit Station Service Transfonners (US3Ts) 11AAX006A and B are also connected to the Class IE, Division I, 2 and 3 Medium Voltage Switchgear through non-segregated phase bus ducts. Non-segregated phase bus ducts from the RSSTs 11AAX005A and B and USSTs 11AAX006A and B to the Medium Voltage Switchgear of Class IE, Division 1, 2 and 3 will be physically separated such that failure of any one bus duct will minimize the likelihood of failure of the other bus ducts. i e =
NRC COMMENT 8.2.2 Availability Of Offsite Power Circuits v i: GDCkl7 requires,in part,that each of the offsite circui(p be desygned to be available in sufficient time following a loss of all onsite alternating current power supplies and other offsite electric power circuits to assure that specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded. Based on information in the PSAR, the staff is unable to conclude that the period of time that the station can remain in a safe condition assuming no immediate ac power is available is greater than the time required to reestablish ac power from the offsite grid to the onsite Class lE distribution buses (reference: SRP Section 8.2, Part III, item 16). This item will be pursued with the applicant and the results of the staff review will be reported in a supplement to this report.
RESPONSE
The CRBRP will be connected to the TVA 161KV grid using four separate connections between the switchyards and the TVA grid as described in Section 8.1 of the PSAR. All of these four transmission lines are kept continuously energized. During normal operation, the electrical power to the plant auxiliary loads is provided from the main generator through the generator circuit breaker,and the unit station service transformers. When the plant is not producing power, the auxiliary loads can be fed from the generating switchyard through the main pwer transforr:er and the unit station serv'.oe transforrers or from the reserve switchyrird through the reserve station service Should a fault occur resulting in the loss of offsite transformers. power from the generating switchyard, while the plant alpxiliary loads are connected to the unit station service transformers, e pwer connections to the medium voltage switchgears including the 4.16KV a [.2 2 - 4
8.2.2 (Continued) Yw sWitchgears of the Class lE system, will be automatically trans-f8rred to the reserve station service transformers. diils transfer o[ power will be accomplished within 6 cycles. The connected loads, in general, will not experience any loss of power. Based on the above, it is evident that offsite power will be restored to the class 1E distribution buses in a very short time without affecting the safe condition of the plant. W .e = C g,2 2 2.
NRC COMMEITI 8.2.2.3 b Secuencino of Loads on the Offsite Power System (. f Thg*offsite power system should have sufficient capacity to supply all required loafs without sequencing of loads on the offsite power system. By letter dated June 1, 1982 the applicant addressed capacity of offsite circuits. Based on this letter the capacity of offsite circuits to block load all connected loads without reliance on the load sequencer is not clear. Clarification of this item will be pursued with the applicant and the results of the staff a supplement to this report. review will be reported 1.n
RESPONSE
The CRBRP system design has no provision of using a load sequencer to switch the loads on to offsite ac power supply. Each one of the offsite ac power supplies is capable of feeding all the required plant auxiliary loads without the need of a load sequencer. However, a load sequencer has been provided to connect various Class lE load blocks (in a pre-selected sequence) to the onsite ac power supply. m 8223-l
NRC COMFINT - 8. 2. 2. 4 The applicant has documented in Section 3.1 of th(-PSAR that y auEomatic transfer *from the ncrmal power source to the(reserve t poser source is initiated by fault sensing relays in the normal s power supp3y. Given loss or failure of the normal power supply, it is not clear how fault sensing relays will assure the avail-ability of the reserve offsite power socree. It is the staf f position in accordance with GCD17 that pro-visions be included to minimize the proLability of losing electric power from reserve offsite power source as a result of or coincident with loss of power from the normal offsite power source. This item will be pursued with the applicant and the results of the staff review will be reported in a supplement to this report. RESPO::SE Primary and backup fault sensing relays have been provided in the normal power supply (Generator, generating switchyard, main step-up transformer and the Unit Station Service Transformers) and the reserve switchyard to perform the required protection of the electrical distribbtion system. Each fault sensing relay provided in the normal power supply will actuate its respective lockout relay on sensing a fault in the normal power supply. The lockout relay will trip the normal (generating switchyard or CRBRP generator) power supplyr_ incoming circuit breakers on the medium voltage switchgear including the a 4.16 KV Class lE switchgear. The tripping of these circuit breakers will automatically initiate closing of the reserve offsite power supply 8.2.2.4-1
(preferred power) incoming circuit breakers on the medium voltage switchgear using the early "b" contact of the normal power supply ~ incoming circuit breakers. [ i 7 -y7 The medium voltage switchgear buses are also provided with undervoltage sensors, which will also initiate tripping of the normal power supply circuit breaker and close the reserve power supply circuit breakers on sensing an undervoltage condition on the bus. In the case of Class lE, 4.16KV medium voltage switchgear buses, the detection of an undervoltage condition will also result in an automatic start signal to the emergency diesel generatar. However, if the automatic bus transfer to the reserve power supply restores the voltage to the medium voltage Class lE switchgear buses, the circuit breaker connecting the diesel generator to the MV switchgear bus will remain open and the safety related loads will be powered fron the reserve power supply. A back-up breaker failure protection scheme is also provided in the event of the f ailure of the above protection scheme. On failure of the f ault sensing relay (s), the f ault sensing relay (s) in the generating switchyard relaying scheme will actuate another 1cckout relay which will trip the 161KV circuit breakers in the generating switchyard, thereby isolating the medium voltage switch-from the normal power supply and will initiate the closing gear of reserve offsite power supply incoming circuit breakers as described abov.e. Additionally, in the event that a fast bus transfer is unsuccessful, a time delayed automatic bus transfer will be accomplished. If this automatic closure of the reserve offsite power supply incomin~g circuit breaker (s) is not accomplished, the 8perator can manually close.the reserve offsite nower sunniv inconEng circuit breaker (s). PSAR Section 9.3.1.1.4 will be revised as attached to include the above description. 8.2.2.4-2
AC Power Supply will remain connected and provide uninterrupted power to the Plant AC Distribution Systtu through the main power transfor=er and the unif station service traeformers. An electrical fault downstream of the O' generator circuit breaker will cause tripping of the 161KY circuit breakers in the generating switchyarr'. This will result in the loss of the power supply from the unit station service transformers. Similarly, an event which trips the turbine or r? actor concurrent with the loss of CRBRP Preferred Offsite Power from the generating switchyard will also result in the loss of the power supply rom the unit station service traitsformers. Fad sptseg ;:. gf; ' :- '" " " :":- 'iposver off" ed pn.e W. k L 7tst m d i';r ' :: ; f t...
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I fT'--, undervoltage sensors at each 13.8KV and 4.16KV switch ear bus will a. 0//d*
- -d initiate the followingp de are c
v A. Trip the supply circuit breakers from the unit station service transform 2rs. B. Close the Reserve AC Power Supply circuit breakers from the two 50 percent capacity reserve station service transformers by means of a fast dead bus transfer schene. /NSENT 2; Provision s included in the desig for testi the trchfer of e power between the u.'t station arvice trans rmers and 'he reser
- ta-tion s rvice transfo. ars. Thes tests are p formed du ~ng prolo ed plant s ' tdown periods simulati loss of th AC power uply fr. the unit sta ion service tra formers a described i Section 8
.1.1.2. 8.3.1.1.5 120/208 Volt Vital (Uninterructible) AC Power System p The 120/208 volt Vital (Uninterruptible) AC Power System is a y. Class IE system which is required to supply AC power to the Plant Protection System (PPS) controls; alarm and indication and other Class IE loads for safe shutdown of the plant. The Plant Protection System (PPS), described in Chapter 7., generates signals to actuate reactor trip, and performs other supporting functions in the event of an emergency condition. The system is divided into three separate and independent load groups (Divirions 1, 2 a-d 3), each receiving AC power from a separate inverter through a static transfer switch. Connections for the 120/205 volt Vital AC Power System are shown in Figure 8.3-2. The normal' source of power for the Vital AC Power Distribution buses are the inverters which are supplied from their associated division DC power supplies described in Sectica 8.3.2. Each 120/208 volt Vital AC Power System Distribution bus can also receive power from a Class 1E 480 volt motor control center which serves as a backup power source. Each of the stribution buses is connected to this motor control center through a stat.. ' tansfer switch and 480-120/208V AC regulating transfomer. Failure of an inverter or its DC power source is sensed and the associated distribution bus is transferred automatically by ~ the static transfer switch to the backup transformer supplied by the Class IE 480 volt motor control center. The transfer is accompitshe*d at high speed and does not degrade the performance of control and ins qumentation loads. '(*\\ ~ j--a n i.: svu y e e
INSERT 2 I 9 .( primary and backup fault sensing relays have been b i provided in the normal power supply (Generator, generating switchyard, main step-u transformer and the Unit Station Service Transformers) and the reserve switchyard to perform the required protection of the electrical distribution system. Each fault sensing relay provided in the normal power supply will actuate its respective lockout relay on sensing a fault in the normal power supply. The lockout relay will trip the normal generating switchyard or CRBRP generator) power supply incoming circuit breakers on the medium voltage switchgear including the 4.16KV Class 1E switchgear. The tripping of these circuit breakers will automatically initiate closing of the reserve offsite power supply '(pre-ferred power) incoming circuit breakers on the medit:n voltage switchgear using the early "b" contact of the normal power supply incoming circuit breakers. The medium voltage switchgear busses are also provided with undervoltage sensors, which will also initiate tripping of the normal power supply circuit breaker and close the reserve power supply circuit breakers on sensing an undervoltage condition on the bus. In the case of Class 1E, 4.16KV medium voltage switchgear busses, the detection of an undervoltage condition will also fesult in an automatic start signal to the emergency diesel henerator. However, if the automatic bus transfer to[the reserve powersupplyrestoresthevoltagetothemediumvoltajeClasslE switchgear busses, the circuit breaker connecting theidiesel generator to the MV switchgear bus will remain open and the safety related loads will be pcwered from the reserve power supply.
I9 b 7 i* 4 -j INSERT 2 (continued) A back-up breaker failure protection scheme is also provided in the event of the failure of the above protection scheme. On failure of the fault sensing relay (s), the fault sensing relay in the generating switchyard relaying scheme will actuate another lockout relay which will trip the 161KV circuit breakers in the generating switchyard, thereby isolating the medium voltage switch-gear from the normal power supply and will initiate the closing of reserve offsite power supply incoming circuit breakers as described abov.e. Additionally, in the event that a f ast bus transfer is unsuccessful, a time delayed automatic bus transfer will be accomplished. If this autcmatic closure of the reserve of fsite power supply incoming circuit breaker (s) is not accomplished, the operator can manually close the reserve offnite power sunniv inconin7 circuit break er (s ). The CRBRP design includes capability to test the transfer of power supplies among the plant power supply, the normal AC supply through the generating switchyard, the reserve AC supply through the reserve switchyard and the onsite standby diesel generator power supplies. The sensors that detect the loss of power will e tested during plant operation or plant shutdown.
8.2.2.5 NRC COMMENT 4 Surveillance of Offsite Circuits { 1 = L L ection 5.2.3 (5) of IEEE Standard 308-1974 requires that off-site power supplies be monitored to the extent that is is shown to be ready to perform its intended functic_, Descrip-tion of the monitoring that is to be provided for Clinch Riv7r offsite power circuits has not been described in the PSAR. This item will be pursued with the applicant with the results reported in a supplement to this report.
RESPONSE
The availability of offsite power supplies to class lE buses is monitored on the Electrical Control Panel in the control room. In the event the incoming offsite power source has undervoltage condition or any one of the protective relays is not reset, the condition will be alarmed on the Electrical Control Panel located in the Main Control Room to alert the operator. In addition, an amber light on the. Electrical Control Panel in the control room indicates that the offsite power supply l'ine and its breaker are available for transfer of power from 'the other source if required. a PSAR Section 8.2.2.1 wi-11 be revised per Attachment 1. $
- 1 r 2' 5 $
.~n ~ m. _._. - - m m.m --- ~ ~ ~--~ = / T TAcM M E N T I .r The CRBRP Preferred AC Power Supply censists of two Ic1KY transmission T.ines in the generating switchyard connected to the main power transformer. In the event of a turoine trip when no electrical fault is pre-l sent, the generator circuit breaker will open automatically and disconnect the Plant Power Supply. The Plant AC power distributic be provided wl;th power by the CRSRP Preferred AC Power g system will then $upply threugh the main power transformer without interruption.. ( 5 In t2e event of non-availability of both the Plant and the CRSRP Preferred AC IFewer Supplies, the Plant AC distribution syste will be transferred t: the Reserve AC Power Supply. This transfer is perfomed within a pericd of 6 cycles by a fast dead bus transfer scheme as described in Section 8.L1.1. Both reserve station service transformers are kept enerp2ed at aT1 times during pNt operation and are available to the i Plant AC distdbution system wi@in a few cycles. This assures that the specified acca;rtable design limfcs are maintained. Reculatory Ga5de 1.93, Rev. 0 (12/74) i i i The easilable off-site AC power sources consist of the CRBRP l Preferred AC Puer. Supply and the Reserve AC Power Supply. Each of these two supplies pmvides two connections to the TVA 161KY grid. The two 161KV grid connecticts to the reserve station service transformers constitute the required indepaadent. off-site power sources. In addition, two 161KV grid connections to the generating switchyard provide an added reliability to off-site power, available through the main power and the unit station ser-vice transformars. j l i l On-site AC power sources and on-site DC power sources comply with i the requirements of CRBRP GDC15 for the availability of electric power ( sources. i p c=oiTi.a u. TucswT Should an LC01" '"~ on these power sources, the plant's con-tinued operation will be restricted in accordance with the Regulatory Guide 1.93 recoceendatiens. IEEE Standard 3Ga-1974 l The Rzserve AC Power Supply provides the two independent circuits of the IEEE Std. 305-1974 "preferrec power supply". It connects the TVA j 161KV grid to each cf the two 4.16KV Class 1E switchgear buses' through the' reserve station service transformers. Hence, the safety-related AC distri-bution system has two physically separate and electrically independent sources available from the TVA grid. { The CRSRP Preferred and the ' Reserve AC Power Supplies, each has sufficient capacity to operate the loads applied during _a design basis ,a accident. Both the CRERP Preferred ano the Reserve AC Power Supplies are l available during normal cperatien (see Section 16.3.9). ? I INSERT 'A ' 1 -i!sedMU l hEV i i
- f. 2 2 D 2.
IN S E R.T A' I9y I i rw I The availability of offsite power supplies to Class lE buses is monitored on the Electrical Control Panel in the control In the event the incoming offsite' power source has room. undervoltage condition or any one of the protective relays is not reset, the condition will be alarmed on the Electrical Control Panel to alert the operator. In cddition, an amber light on the. Electrical Control Panel in the control room will i..dicate that thd offsite power supply line and its breaker are availab3e for transfer of power from the other source if required. E Y m
NRC COMMENT 8.2.3.1 5 b The Clinch River design. includes provisions for transferring powet between the plant power supply, the normal ac power supply through the generat4ng switchyard, the @ serve ac power supply from the reserve switchyard, and the onsite standby dies 41 generator power supply. By letter dated June 1,1982, the applicant has implied that the design capability to test the transfer arong the above listed power. supplies during power operation has not been provided.in.accordance with GDC 18. It appears that the sensors that detect loss of the plant and normal power supplies, the transfer between the plant and normal supplies, and the transfer between the plant and onsite power supplies cannot be tested during normal plant operation. The justification for this apparent noncompliance to GDC 18 will be pursued with the applicant anl the results will be reported in a supplement to this report.
RESPONSE
The CRSRP desian includes capability to test the transfer of power supplies among the plant power supply, the normal AC supply through the generating switchyard, the reserve AC supply through the reserve switchyard and the onsite standby diesel generator power supplies. The sensors that det2ct the loss of power will be tested during plant operation or plant si.atdgn. s PSAR Section 8.3.1.1.4 will be revised as attached with response to NRC comment 8.2.2.4. e ? b 8 2.3.1-l
B.1.1.1 NRC CO!OiEITT Y 5: ? s Enterconnection Between Redundant Divisions b 6 in Section 8.3.1.2.1 of the PSAR, the applicant has stated that "the standby onsite power supply network has provisions to manually cross-connect the 4.16 kv buses of the division 1 and 2 power supplies in case of extreme emergency." By letter dated June 1, 1982, the applicant defined extreme emer-gency conditions to be loss of offsite power, loss of one diesel generator, and failure of a critical system load on the remaining operative diesel generator. It appears that the failed load, since it has been characterized as critical, is needed to mitigate the consequences of some design bases event. Thus, it appears that the interconnection between division A and B will be used to meet the redundancy requirement of GDC 17 at the expense of the independence requirement of GDC 17. The subject interconnection does not meet GDC 17. Resolution of this item will be pursued with the appliiant and the results of the staff evaluation will be reported in a supplement to this report.
RESPONSE
The Class lE electrical distribution system consists of three functionally redundant divisions regarding shutdown capability as described in Section 8.3.1 of the PSAR. Any of tnese three divisions has the capability to safely shut down the plant. The Class IF Divisions 1 and 2 have a provision for manual cross-connection as an added conservatism in the system desig2. as described in Section 8.3.1.2.1 of the PSAR. This$ manual cross-connection will only be used under en extreme emergency condition per the criteria for independence as described in response to Question CS430.5 (see letter of June 1, 1982). 8.3.1.1-1
Y 8.3.1.1 (continued) b k I (The postulated emergency also considers multiple equipment g Ifailures which is beyond the single failure criteria and also cons.i ders loss of all four offsite power sources and as such should be considert.' to have a very low probability to occur. It should be noted that the failed load is not needed to mitigate the consequences of any design basis event. The system design meets all redundancy requirements of GDC17 witnout the need of a manual cross-connection. It should also be noted that the design of the manual cross-connection between Class lE Divisions l and 2 fully meets the criteria for independence of Regulatory Guide 1.6. Response to question CS 430.5 will be revised as attached: m = 8.3.1.1.-2
page 5 W82-0298 (0,22) 42 U Mechanical and electrical interlocks have been provided to prayent an 3) operator error that would result in paralleling of standby power sources; i 4F Tho circuit breakers used for the cross-connection will norma 1I J be stored 2 in separate locked dummy compartments. -Q c ' r; ;f ".: f:r r'"' "cr^- ,' :r ;: ' ;r.t v.; : i: c':--ed 'a **e 00"* ' ~.;;;. 1 Therefore, there is no non-compliance with the Regulatory Requirements. PSAR Section 3.1 will be revised to include the following paragraph: Provision has been made in the safety-related AC distribution system design, for manual cross-connection between the 4.16kV switchgear buses of Class 1E Divisions 1 and 2. Manual cross-connection details are as described in Section 8.2.1.2.1 of the PSAR. MO m g&y s W s) be WCL=? 2-ceng g cetrm. 04 A Yh M v %m 6s. 2 e% W# r ~ ~ d QCS430.5-2 /cend. 69 May 1982 82-0307
8.3.1.2 NRC COMMENT I9 Fuitable Electric Interconnections Yi b 6 The terminology " suitable electric interconnections" contained in criterion 26 of Section 3.1 of the PSAR is inconsistent vith terminology contained in GDC 17 (applicant's design criterion 15). GDC 17 recuires that the onsite electric dis-tribution system have sufficient independence and redundancy to perform its safety function assuming a single failure. The applicant's criterion 26 terminology " suitable electric inter-connection" allows electric interconnection between redundant distribution systems in violation of the independence require-ment of GDC 17. It is the staff position that the termine3ogy " suitable electric interconnection" be deleted from criterion 26 of the PSAR. This item will be pursued with the applicant and the results of the staff evaluation will be reported in a supplement to this report.
RESPONSE
The terminology " suitable electric interconnections" as included in criterion 26 of PSAR Section 3.1 has been used to describe the electrical connections between the electric power distribution system equipment and the loads of the heat transport system. The terminology has not been used to describe any connections between redundant Class lE divisions of the electric power dis-tribution system. However, in order to avoid any inconsistencies with terminology contained in GDC 17, the criterion 26 will be revised to =dcicte " suitable 41; ic interconnections" as por the attachment. E .f
K -J w 4 V L Criterion 26 - HEAT TRANSPORT SYSTEM DESIGN h i [ The heal transport system shall be designed to relfably remove Z heat from the reactor and transport the heat to the turbine-generator or ultimate heat sinks under all plant conditions including nomal operation. _'- anticinated operational occurrences and postulated accidents. Con.- sideration shall be given to provision of independence and diversity to provide adequate protection against comon mode failures. The system safety functions shall be to: (1) Provide sufficient cooling to prevent exceeding specified acceptable fuel design limits during nomal operation and following anticipated operational occurrences, and (2) Provide sufficient cooling to prevent exceeding specified acceptable fuel damage limits and to maintain integrity of the reactor coolant boundary following postulated accidents. Folic, wing the loss of a flow path, the heat transport system shall include at least tu independent flow pathp, each capable of per-forming the safety functions following shutdown.ll),.gg/TM /Nuh% O The system shall include yleak detections, isolation and containm' erit cipTb'iM6ssu7i~WaY fonnsite y electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the safety function can be accomplished, assuming a single failure. (I This requirement is not intended to preclude two-loop operation provided the system safety functions can be appropriately met. Resoonst: The primary heat transport system (PHTS) is being designed to accomodate the themal transients resulting from the normal, upset, emergency (anticipated operational occurrences), and faulted conditions (postulated accidents) described in Appendix B. . The system will be designed such that a nomal or upset event - does not adversely affect the useful life of any HTS components. Following an emergency condition, resumption of op'eration will be possit:1e following repair and re-inspection of the components, except that the primary coolant pumps (damaged or undamaged) will aintain 32 V 3.1-45 '~ =d. 32 5. TE
8.3.1.3 NRC COMMENT b Redundancy of the Three Independent Load Groups i 4, $ection 8.3.1.1 of the PSAR indicates that three independent-load groups are provided with Load group 1 redundant to load group 2. No description as to the redundancy of Load group 3 was provided in Chapter 8 of the PSAR. By Letter dated June 1, 1982, the applicant indicated that each of the three load groups has the capability to shut down the plant safely and that since not all the loads in Load group 3 are identical or similar to those in Load group - and 2, Load group 3 has not been identified as redundant rv L. ad groups 1 and 2 in the PSAR. Even though Load group 3 loads are not identical or similar to Load groups 1 and 2 it appears that the three Load groups should be functionally redundant since is has been stated that each has the capability to shut down tne plant safety. Clarification of this item will be pursued with the applicant and the results of the staff evaluation will be reported in a supplement to this report. In addition, Section 8.3.1.2.1 of the PSAR states that the Class lE safety related loads are separated into three load groups such that loss of any one group will not prevent safe shut-down of the plant. This statement implies that as a minimum the remaining two load groups are needed to shut down the plant. This statement contradicts other statements in the PSAR that imply that only one load group is needed to shut down the plant. This contradiction will be pursued with the applicant in coordination with RSB and the results o'f the staff evaluation will be reported in a supplement ti this report. 8 3 el 3 I
t 8.3.1.3 (continued) g, b E
- hES PONSE
T + 6 tach of the three load groups of Divisions 1, 2 and 3 has the capability to shut down the plant safely and as such is considered functionally redundant. Only one load group is required to shut down the plant. As such the loss of any two load groups, including a single f ailure condition, will not prevent safe shutdown of the plant. The PSAR Section 8.3.1.2.1 will be revised (as attached), to state that only one load group is required to safely shut down the plant. m a m 8.3.1.3-2
~ INClub/NQ A S/NGE FAILUAE ccWh17]oN 8.3.1.2.1 NRC eculatorv Guide 1.5, Rev. 0 (3/711 'TMO The C ass IE safety-related loads are physically and electrically ( separated int three lead groups (Divisions 1, 2 ano 2) suph that loss of 1 Na. grou will n t prevent safe shutdown of t'se slantF;.x 2 a '#
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') ___,..,,,,,3 ~L ::yuni.r~iouhaty gebuubMT snu7boWN/ Each AC 1 cad group will have* connections to the CRBRP Pr(ferred j Pswer Supply, Reserve, Power Supply and a Standby On-site AC Powers $curce. liie Standby On-site AC Power source will have no automatic connection to any / of.her redundant load group. / i ~ When operating from the Standby On-site sources, redundant load .I groups and the redundant Standby On-site sources will be independent of each l other as follows: u a. The Standby On-site source of one Class 3E lead group will not f be automatically paralleled with the Standby On-site source of another Class 1E icad group under normal or emergency con-ditions. b. No provisions exist for automatically connecting one Class JE lead group to another Class IE load group. c. No provisions exist for automatically transferring loads between redundant Class IE power tources. d. Manually connecting redundant lead groups together will k require at least one interlock to prevent an cperator error I that would parallel such Standby On-site power sources. l l Each Diesel Generator unit consists of cne diesel engine, one i I generator and required accessories. The Standby On-site Power Supply network has a :rovision to l maneally crcss-connect the 4.16KV buses of the Divisien 1 and 2 power supplies in case of an extreme emergency. This connection will be put into t j service through strict administrative controls and nust satisfy the i following prerecuisites: 1 l a) Taere.shall be a total less of off-site pcwer. b) One of the two redundant diesel generators failed to start and it is determinec to be inoperable. c) Critical safety-related leads associated with the operative diesel generator have failed and beco=e unavailable. If the above prerequisites are met, leads of either redundant Divisien 1 or 2 can be connected to the diesel generator of the etner divi-s:lon for safe shutdown of the plant and to maintain the plant in.a safe shutdown condition. Key and electrical interlocks and administrative controp will be provided to ensure: ~,, e-d 5 3--, f OWLY O h!E LoAp qEcuP I s. = =. 19E1 REf2UIRED To SHUTbowAl THE PLANT sA FG1X., 83.13-3
8'.3.1.4 NRC COMMENT l 6 Non-Class IE Loads Powered from Class lE System .1: Se*ction 9.3.1.2.14' ofthePSARindicates'thatNon-ClahhlE L l loYds will be connected to one division of the Class 1E system through an isolation device. a) The proposed design, for the isolation device, primarily addressed protection of the Class 1E system due to worst case faults in the non-Class 1E system. By letter dated June 1, 1982 the applicant indicated that faults and failure modes other than the worst case fault (three phase) have also been addressed in the design of the isolation system. Protective devices have been provided in the design to clear any fault on the non-Class 1E system such as phase to ground, phase to phase, and three phase faults, within a reasonable time such that there will be no degradation to the Class 1E System. A phase to ground fault (which is the most likely mode of failure) on a non-Class lE circuit will have no effect on the Class lE system since the isolation system includes a 4.16kV/480V delta-wye connected trans-former with the high resistance grounded neutral. The neutral is grounded through a 55.4 ohm resistor which will limit the phase to ground fault current to approximately 5 amperes. The Class lE 480V and 4.16kV circuit; breakers will be tripped to clear a ground fault in the c{se that the affected non-Class 1E breaker fails to trip. F 3. I 4r -l
J An'y phase to phase or three phase fault on the non-Class lE circuits will be isolated by instantaneous operation of the affected branch feeder circuit breaker. Back-up protection .s-is provided by fast operation of the 480V supply pircuit 7 breaker (0.2-0.3 see clearing time) or by the 4.lEkV unit I substation transformer feeder circuit breaker (0.6-0.7 sec clearing time). In addition undervoltage sensors are provided at the input terminals of the 480V supply circuit breaker. These undervoltage sensors will initiate tripping of the 480V and 4.16kV circuit breakers within five (5) seconds upon sensing the undervoltage caused by loss of power or failure of the circuit breakers to clear a fault. Failure modes such as the Class lE breakers failing to operate, high voltage being imposed on the output terminals of the transformer or isolation system and proposed testing have not been addressed. These items will be pursued with the applicant and the results of our evaluation will be included in a supplement to this report. b) The isolation device is to be designed as indicated in the PSAR so that voltage on the Class lE system buses will not drop below 70 or 80 percent of nominal given a worst case fault in the non-Class lE system. With most Class lE equipment designed to operate at not less than 90; percent of nominal, the staff is concerned that Class lE 5.ay not operate at the lower voltage. By letter dated June 1, 1982 the applicant stated: 4 B 2./ 4-2
J The isolation system is designed so that impedance of the system is high enough that the worst possible fault (three phase bolted fault) on the 480V non-Class lE bus pill not degrade the voltage at 4.16kV Class 1E bus below(she 7 T I following levels: (1) When the 4.16kV Class IE bus is being supplied from offsite power supply, the voltage at the bus will not drop below 80 percent of nominal. (2) When the 4.16kV Class lE bus is being supplied from onsite (standby) power supply the voltage at the bus will not drop below 75 percent. The minimum voltage levels of 80 and 75 percent of nominal are chosen to be the same as the allowable minimum voltage levels during the sequential loading of the 4.16kV Class lE bus or during starting of the largest motor after th. bus has been fully loaded. As discussed in a) above, any fault on 480V non-Class lE system will be cleared within five (5) seconds. After the fault has been cleared the voltage at the 4.16kV bus will be restored to a minimum of 90 percent of nominal within two (2) seconds, which will allow all connected loads to operate continuously. Y m h m g. 5. t. 4, ~
4 voltage drop and its affect, when failure of non-Class lE loads occur at the same time the diesel generator is sequencing loads, has not been addressed. This item gill be pyrsuedwiththeapplicantandtheresultsofthestaff i ? eyaluation will be included in a supplement to this report.
RESPONSE
a) As described in Section 8.3.1.2.14 of the PSAR, the isolation system will consist of a 4.16kV circuit breaker, a 4.16kV/480V hiah imoedance transformer and a 4Rnv circuit breaker, as shown in Figure 8.3 -3 of the PSAR. The transformer and both breakers will be qualified as Class lE equipment. Normally a fault in the non-Class lE system will be cleared by the non-Class lE feeder circuit breakers. However, if these breakers fail to operate, the back-up prc tection will be pro-vided first by the 480V Class lE circuit breaker and then by the 4.16kV Class lE circuit breaker. The system design is such that a single failure will not prevent t'.? isolation of the faulted non-Class lE system from the Class lE system. The failure of both Class lE circuit bre eers to trip (event beyond the single failure requirement) undel. fault in the non-Class 1E system may result in the loss of Class lE Division 3 power supply depending on the magnitude of the f ault on the non-Class lE system. However, either of the Class lE DivisionE 1 and 2 will adequately provide the capability to shut down the plant safely. 8.3.1.4-4 Any f ault with the Class lE transformer of the isolation system, resulting in high voltage being imposed on the outputgterminals i df the transforme'r or isolation system will be detectgd and 4e} eared by the 4.16kV Class lE circuit breaker. The equipment will be tested at manufacturer's facility prior to delivery. Initial preoperational tests will be performed with the components installed and connected to demonstrate that the equipment operates within design limits and that the system meets its performance specifications. Periodic tests will be performed at regular intervals to verify the performance and condition of the protective equipment and system. For more details, refer to Section 8.3.1.1.2 of the PSAR. The design of the protective system will ensure that the prot. active relays and devices are testable during normal power operation and during refueling periods. The high impedance transformer will be subject to a short-circuit withstand test in the manufacturer's facility to verify the transformer current limiting capability, as described in response to question CS430.15. b) During sequential loading of the Division 3 diesel generator, all the Class 1E loads, including both 4.16KV/480V transformers, will be sequenced first; The non-Class 1E loads will be connected by closiIng of the 4 80 volt Class IE breaker after all Class lE loads have been connected. The 4.16KV bus voltage and fre-quency would have been restored and stabilized to the 8.3.1.4-5
, nominal values prior to connecting of non-Class 1E loads. The isolation system will be designed so that any fault I in the non-Class lE system during or after the seguential loading will not degrade 4.16kV bus voltage and fibguency y I below the levels described in response to questiorr 1' CS430.15. O en b 2 3 l'4-4
8.3.3.1.1 NRC COMMENT Environmental Qualification of Cables ar.d Terminations ? S'ection 8.3.1.4 of the PSAR states that environmentalOtype st will be performed on cables and terminations that are required to function in a hostile environment. This statement implies that cables or terminations that are not required to function in a hostile environment will not be environmentally qualified and may not be in compliance with IEEE Standard 323-1974. By letter dated June 1, 1982, the applicant pro-vided the following corrected statement: environmental type test will be performed on all cables and terminations for their expected environment. Pending documentation of this corrected statement, we conclude that there is reasonable assurance that cables and terminations will be designated to be environmentally qualified and is, therefore, acceptable.
RESPONSE
Updated Section 8.3.1.4 as provided with the response to question CS 430.9 will be included in the revised PSAR. M m 8.3.3.1.1 - 1,
8.3.3.3 !UC CD! FEE e a y s 4 L Iridependence - (Ccrpliance With General Desian Criterion (GDC)17 a. Physical Incbpendence of Cables Section 8.3.1.2.14 of the PSAR indicates that physical separation of circuits and equ.ipnent mmprising or associated with the Class lE pcuer system, Class 1E protection systems and Class 1E equi rent, I will be in accordance with criteria set forth in paragrait 8.3.1.4 of the PSAR. Separation criteria described in Secticns 8.3.1.2.14 and 8.3.1.4 of the PSAR was not clear and did not meet the guide-lines of IEEE Standard 384 and Regulatory Guide 1.75. For example, the PSAR indicated that non-Class IE cables in panels will be separated from Class 1E cables so that they will not provide a cam-bustion path between different divisions. Section 5.6.5 of IEEE Standard 384-1974 states that ncn-Class lE cables shall be separated by six inches or a barrier. In general, no criteria has been chserib-ed for separation of Class lE and non{ lass IE cables. Other examples include: (1) no criteria for separation between cables trays and conduits of arother division, (2) confusing criteria for the separation of the third divisitn (the cbsign indicates, there are three divisions but only two redundant divisions. Separation critcria refers to the two redandant divisions in many cases versrE the three divisions), (3) confusing definition for associated cat tes, (4) no criteria for separation between associated cables and ncMlass IE cables, arel (5) no criteria before and after an isolatica chvice.
8.3.3.3 (continued) By htter dated June 1,1982, the applicant stated that thEseparation g design criteria for Clinch River is fully consistent with the guide-4 lines set forth in IEEE Standard 384-1974 and Regulatory Gdde 1.75 (Revision 2). In addition, the applicant provided a revised PSAR Section 8.3.1.4 (item F) to clarify eact) of the above cbscribed examples of noncxrpliance. Based on a review of the information m ' tained in the revised PSAR, the following items remain as concerns: (1) Achquacy of metal conduit or steel wire ducts as barriers inside panels, (2) routing of ron-Class lE cables in the same ra way with Class lE cables, (3) location of a referenced Attachnent I, and (4) RG 1.75 requirenent that associated non-Class lE circuits reet all requirerents of Class lE circuits. 'Ihese concerns will be pursued with the applicant and the results of the staff evaluation will be reported in a supplerent to this report. RESPO:EE: 1. PSAR Section 8.3.1.4 (iten F) c' rrently includes the design that retal conduits, fire barriers or steel wire ducts ray be used in addition to the Regulatory Guide 1.75 spacial separation requirenent of six (6) irches. Where used, this design will be nore conservative than the use of wires with only six (6) inches of spacial separation as required by Pegulatory Gide 1.75. 2. Routing of non-Class lE cables will not be in the sane raweay with Class lE cables. This_is identified in Section 8.3.1.4, paragraph E 8.3.3.3-2
a b B.3.3.3 (o21tinued) r e P b ~ + ( y of the revised PSAR pages included in response to Omstion CS 430.10 3. Attachmnt I identified in the response to O stion CS 430.10 consists of the revised PSAR pages for Section 8.3.1.4 of the PSAR. 4. 'Ihe requiremnts on electrical cables are identified in Section 8.3.1.4, paragraphs B and C of the revised PSAR pages transmitted in response to Question CS 430.10. Tnese requirements apply to all cables (Class E, associated and ron-Class E) and are consistent with the guidelines of Reg. Guide 1.75. W h
CSL30.10 - Page 11 of 19 h) Containment Isolation System (CIS Logic Train Actuation wiring is routed through two independent conduits. One conduit contains I wiring.from only one CIS Log'c Train. No intermixing of CIS Logic ( trains within a conbeit is permitted. CIS Logic Train 1 wiring is routed from CIS Logic Panel 1 to CIS Breaker 1 in the Intemediate . Building. CIS Logic Train 2 is routed from CIS Logic Panel 2 to CIS Creaker 2 in the Intermediate Building. t-y 1) The wir'ing from a PPS buffered output which is used.for a non-PPS E purpose may be included in a PPS rack. The PPS wiring is 4 separated from the non-PPS wiring. The amount of separation is I defined on an individual case basis; however, it is designed to meet the requirements of IEEE Std. 38af and Regulatory Guide 1.75. '- -19 7'l j) Containment Isolation Yalve actuatien wiring (for either manually or automatically initiated actuation) to the Inside Containment and the Outside Containment Isolation Valves are separated as Division 1 and Division 2 cabling, respectively, k) Rigid, metallic, completely enclosed and unvented raceways arr considered acceptable for any of the above applications as thy are ecuivalent to rigid metal conduit, as defined in IEEE Std.100 and NFPA 70. 1) The physical separation between PPS conduits, containment penetra-tions, or panels is in accordance with IEEE Std. 384-1974 and Regulatory Guide 1.75 to provide assurance that a credible single event cannot simultaneously degrade redundant protection channels ( or shutdown systems.. Q,:~? m) The Primary, Steam Generator Auxiliary Heat Removal System (SGAHRS) channels and logic outputs are treated and separated as Primary PPS signals. The primary SGAHRS logic output is kapt separated frcrn the Secondary SGAHRS logic output channels. The Secondary SGAHRS channels and logic outputs are treated and separated as Secondary PPS signals. The Secondary SGAHRS logic output is.kept separated from Primary PPS, CIS and non-PPS outputs. Redundant SGAHRS logic train outputs are separated from each other. The manual trip and reset inputs to each SGAHRS divisional latch logic art. 4r routed and separated as redundant PPS signals separated from the automatic SGAHRS logic outputs and all other PPS and non-PPS channels. F. Cables Within Control Board and Other Panels SEE l@El2.T .3 thin cent boards and p[her pfnels, ha.. esses of diffefnt division are provid with a minip of'6 inches.ree air separat on. +. ied. MetF c MMt, fire-bar ers, 4t ec1 4 r.: ict:..b.-::: m:P - i_.ders tor-ma rain independe e withou add i onei-- e4 s ratio ' over that requi ed by Regulator Guide 1. 5. No -Class IE ring not ornessed togeth with Class IE abl e. r d .,u -f..:. .... a.. .....u. ...a ...u u. n. .a
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mn r [ Q g' -d" []' 9 '.' " ] [}~g g / l N a.a=0 ^~ f M AuG5 n b5 gmeng 53 Dec. 1981 kN 8 333- ~ NsswT 3' F. Cables Within Control Board and Other Panels y Within control boards and other panels, harnesses of different divisions are provided with a minimum of six (6) inches free air separation. Thp? design of some control boards or panels also includes the use of metal conduits, fire barriers or steel wire ducts in addition to the six (6) inches air separation. Where used, this design will be more conservative than the use of wires with only six (6) inches of spacial separation as required by Regulatory Guide 1.75. Non-Class lE riring is not harnessed together with Class lE cables. Non-Class lE wiring is separated from Class lE or associated Class 1E wiring in a similar manner as between different divisions as described above. M e
NRC CDfDTI e-8.3.3.3 c w Pfpe Break Protection 1 Separation of Class 1E ra ways from high energy pipelines as mfined in the PSAR is to be greater than 15 feet or less than 15 feet if the pipe is suitably restrained so as not to ship and strike the raceway. Current regulatory guidelines require that the Class 1E raceway be protected so that pipe whip missiles, jet upingenent or envirarr: ental effects of the pipe break will not cause failure of the Class 1E ra way. Fifteen feet of spa is not considered adequate prutection. By letter dated June 1,1982, the applicant stated that any danage to cable trays caused by pipe stip, missiles, jet impingenent, or envirt= mental eFeet will be limited to the sane safety division to which the pipe k ongs. 'Ihe two other divisions, each capable of shutting 6:En the plant, will m ain unaffected by the pipe break. 'Ihus, the staff concludes that the final sign will neet the guidelines of sections 4.1 and 4.2 of IEEE Standard 308-1974 and sections 4.1 and 4.4 of TE Standard 384-1974, the independence requirerent of GDC 17, and is, therefore, acceptable with one exception. Section 8.3.1.4 states in contradiction to the above statenent that "Under no circu~ stances do safety-related racenays run less than fifteen feet from high-energy pipelines of the opposite safety system." Oar original conmrn, fifteen feet of spa is not considered adequate protection, runains as a can rn. 'Ihis c:n rn in add.essed in Section 3.6.1 of this report. MbPONSE: 'Ihe response to Omsticn CS430.13 stated that: " Additional protection will be provided against any single Class 1E Division cable tray damage d to high energy pipe khip missiles by restraint of high energy pipe lines in the
8.3.3.3 c (continued) ? r ? w w s E 4, 7 vicinity of Class lE racxuays. 'Jhe design of restraints and/or barrierr will be determined by analysis to neet BTP APCSB 3-1, rather than the arbitrary 15 foot distan." 'Jhe PSAR, Section 8.3.1.4 will be revised as shoci on tne attadied rark-up. W e.
~ CS430.10 Page 7 of 19 In Non-Hazard Zones, a minimum horizontal clear space [of three feet is maintained between cable trays of different divisions # If a hort-zontal clearance of less than three feet is unavoidable, a fire barrier em w :. ';;; : ' "" M... P : t :;; is provided between the civisions.u {, Yertical stacking of cable trays of different divisionGis avois ed ! wherever possible. ' Where cable trays of different divisions are' stacked . vertically, a minimum clear spa (ce of fiv f et is proviced betwel! the. 4, divisions.24 M A #* /. d'eW p**o f y . s s, a. p
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Fire Hazard Zong In fire hazard renes, Class IE conduits, trays, wireways or raceways of only one safety division are routed. This division is suitably protected by fire barriers and fire protection systems to mitigate the effects of fire in this zone on the safety function of the other safety groups. Ecuipment Hazard Zone (Pice Ereak Hazard Zone) To the extant practical, Class IE cables are routed in areas remote from high energy piping or areas of potential sodium fires; if una-voidatle, the following p ons are taken: soasnottowhicllfAf a) Itaceway re not less than ifteen feet from a high-energy pipe. - r" <dC line unless t e pipeline is uitably restrain and strike the raceway. Thi. spacing applies egardless of whether the hig energy pipel e is a safety 5 tem or non-safety system pipeline. The exceptic to this conside tion is the h' acceptability of 'te mechanical ailure of one s ety system damaging the cable
- hat provides rvice to compo nts/ systems of the mechanical systag that has fai n# t m
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~ sy x b) Redundant Class IE circuits are routed or protected such that a postulated event in one system and division cannot preclude th' operation of the other redundant system or division. c) In all arecs of the plant, the separation between redundant
- y 1E cable raceways takes into consideration the presence of rotating equipment, menorails and eouipment removal paths and the possibility that heavy equipment could be lifted and drepped and possibly czuse failure of two raceway channels. Where this is the case, the minimum separation is such as to preclude this
, possibility. d) In general, Class IE electrical distribution equipment (e.g., switchgear, motor control centers, etc.) is not located in areas where high energy piping or other similar hazards are ' located. + e. ~..u
- . :::1 8.3 28 6 -
8-333-7
/ A/SER T 5 OERP has three (3) Class IE Divisions with emplete physical separation between divisions. Any da:: age to cable trays caused by pipe whip missiles, ? jet inpingcraent, or enviromental effect will be limited to the sare safety e division to dich the pipe belongs, and the tvo >ther divisionq capable of $, safely shutting dom the plant will remain unaffected.
- Additional protection will be provided againct any single Class 1E Division cable tray danage due to high energy pipe whip misciles by restraint of high mergy pipe lines in the vicinity of Class 1E raceways. 'Jhe design of restraints and/or barriers will be determined by analysic to meet Br APCSB
~' 3-1 W m
t 8.3.3.3 WRC COMMENT e-eh Associated Circuit Compliance With All Requirements Placed + On Class lE Circuits 4 %7 Section 8.3.1.2.14 of the PSAR states that associated circuits will be installed in accordance with the requirements placed on Class lE circuits such as separation from non-Class lE cables, cable derating, environmental qualification, flame retardance, splicing restrictions and raceway fill limitations. Based on this PSAR statement, it appears that associated circuits may meet only the requirements listed. Items not listed such as protection from design basis events, quality assurance, and seismic qualification of the associated circuit from and including its supply breaker to and including the actuated el Epment, are of concern. In accordance with position C.4 of Regulator Guide 1.75, it is the staff position that associated circuits meet all requirements placed on Class lE circuits. This item will be pursued with the applicant and the results of the staff evaluation will be reported in a supplement to this report.
RESPONSE
The associated circuits will be installed in accordance with the requirements for physical and electrical separation of Class lE cables as described in Section 8.3.1.4 of the PSAR and response to question CS430.10. The Section 8.3.1.2.14 (item f) of the PGAR will be revised as per the attachnent. W m
r = .ba The isolation system will. be acle to accept any single com-e. ponent fatture concu. rent with the worst-fault on the [ Non-Class IE ABDV bus 'd?.n* unacco. 41e conseconce i. (This coes not incluce shcrt cierut 3r the A "6KV one. e tion of tk isclatica system since s;.;; 4; wnsiderec an utensten cf the Class IE bus). a f. Undervoltage sensing will be provided on the 480V side of the transformer. Its function will be to isclate the hen-Class 1E Icats if an uncervoltage condition, caused by a fault on a Non-Class 1E Icad. exists on the 483V bus. gg The system is designed to ' seep the number associated circuits to a bare minimum. The associated circuits es defi c in paragraph 4.5 of IEEE 5tc. 3Ec-1974 are insta14_ _ P- -- C _ h __placee cecercance wit tne reevirements Cla s s IE_ci rcui t C-T_m _ -- __m y"%,__l --? f ' - - - - _ _' - ~ _ - - - -_--- ? ? ' y t^^:_ _J .ne ar.a ayses anc testing ef~aT1c'tiated_, c _ _ _ circuits will ne performec in accorcance witn paragraces 4.5(3). 4.6.2 an.1 5.1.1.2 of IEEE Ste. 364-1974.- The cable installation cesign orcnibits the use of cable spicing insice the cable tray or concuit raceway system. The physical identificetion cf Class IE ecuipment, cables and race =ay systems are cescribec in Section 8.3.1.5. The design provides two separate cable screading rooms, one abcve the Control Room anc one below it. The cesign goes net pe mit location cf any high energy e:uipment in the cable s:reacing rooms as recuired by IEEE Std. 354-1974 The criteria for routing cf circuits in the cable screscing roo_s is given in Section E.3.1.4 The Divisions 1, 2 anc 3 C* ass 1E stancey Diesel Generater units are described in Section 8.3.1.1.1. Tne ciesel generatcr units and assc-ciated aur.111 aries and centrol equipment are locatec in se;arate 5eismic Category I structures having incecencent ventilating systet.s. The crysict 1 separation of circ 6tts related to recuncant Stancby Diesel Generatcrs are routed in accercance with the criteria specifiec in Section E.3.1.4 The Non-Class 1E and Class IE DC batteries and relatee uninterruc-tible power succly (UPS) ecutoment are cescribee in Secticn E.3.2. CC battery and associated UPS ecutement of eecn safety civision is secaratec from equipment of the other safety civision by reinforcee concrete = alls. The Class 1E batteries and UF5 ecuipment are locatec in Seismic Catetery I structures. The pnysical secaration of circuits related te each secarate civision of tatteries and UP5 system is in accercance with tRe criteria cescribed in Section 8.3.1.4 ' : n.7
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4 8.3.3.3 g NRC COMMENT e k ? Physical Separation of Class 1E Eauipment Y It is the staff position that Class lE equipment that supply power to different load groups should be located in separate rooms of a seismic Category I building. Based on information in the PSAR, the staff can conclude that each diesel generator will be located in a separate room and that two of the three 4.16kV Class lE switchgear busses will be located in separate rooms. The separation of the remaining Class lE equipment is not clear. This item will be pursued with the applicant and the results of the staff evaluation will be reported in a supplement to this report. RESPONSE-All Class lE equipment including the diesel generators, 4.16 kv switchgear, unit substations, motor control centers, control room panels, etc. are located inside seismic Category I auildings. Each division of Class lE equipme'at of Divisions 1, 2, and 3 are located in separate rooms which are separated by a minimum of 3 hours rated fire barriers. For the purposes of equipment location and raceway system, all three Class 1E divisions are considered redundant and meet the physical and electrical separation design criteria set forth in IEEE Standard 384-j974 and Regulatory Guide 1.75 and as desribed in Section 8.3.1.4 of the PSAR. e 8.3.3.3-10
8.'.1.2.4 NRC Reculatory Guide 1.29, Rev. 3 (9/78) 3 The Class *E Electric Systems, including the auxiliary systems for the Onsite En:tric Power Supplies, that provide the Class IE electric D power needed for functioning of nuclear safety related equipment are designated as Seismic Category I. 1: All electric devices and circuitry involved in ge'nerating signals
- that initiste protective action are designed as Class IE.
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-S': ': / A[$@7 Z) Those portions of structures, systems or components whose con-tinued function is not required but whose failure could reduce the func-tioning of any nuclear safety related equipment to an unacceptable safety level will be designed and constructed so that the SSE would not cause such a failure. Seismic Category I design requirements will extend to the first seismic restraint beyond the defined boundaries. Those portions of struc-tures, systems, or components wriich form interfaces between Seismic Category I and non-Seismic Category I features will be designed to Seismic Category I requirements. For seismic design classifications, refer to Section 3.2.1. 8.3.1.2.5 NRC Reculatory Guide 1.30, Rev. 0 (8/72) The Quality Assurance requirements for the installation, inspec-V tion and testing of instrumentation and electrical equipment during the plant construction, are those included in ANSI N45.2.4 supplemented by R e g u l.= '.. Guide 1.30 as follows: ANSI N45.2.4 will be used in conjunction with ANSI N45.2-1977. ANSI N45.2.4 requd rements will be considered applicable for the installation, inspection and testing of instrumentation and electric equip-ment during the plant operation. 8.3.1.2.6 NRC Reculatory Guide 1.32, Rev. 2 (2/77) The electrical separation and independence of redundant (Divisons 1 and 2) and Division 3 Standby AC Power Supplies conform to IEEE Standard 308-1974 supplemented by Regulatory Guide 1.32 as follows: Electrical independence between redundant Standby AC Power Supplies will be in accordance with Regulatory Guide 1.6 as described in Section 8.3.1.2.1. Physical independence between redundant Standby AC Power Supplies will be in accordance with IEEE Standard 384-1974 supplemented by Regulatory Guide 1.75 as described in Section S.3.1.2.14 of V M ?1 B.3-25
INSERT 4 t~ All Class lE equipment including the diesel generators, ~ 4.16KV Switchgear, Unit Substation, Motor Control Centers, Control Room Panels, etc. are located inside Seismic Category I buildings and are designed as Seismic Category I. All non-safety-related equipment located in Seismic Category I buildings are designed to maintain structural integrity under a seismic event and will not become missiles. W e
6 n v C. Haceway Fill A ? x g, Cable tray fill will te itetted such that the summation of the crosssectional areas of cables in a tray section will in general be not more than 10. of the usable cross-sectional area of that tray section. Conduits will be staed for a maximum siercent fill of the inside area of the concuit in accordance with NFPA 70 " National Electrical Code" Art. 346. D. Sealino Raceway Blockouts and Wall and Floer Penetrations Fire stops will te installed for cable trays wherever the cables pass through fire walls and floors other than the Reactor Containment vessel. Cable and caole tray penetrations of fire barriers are sealed to provice protection at least ecuivalent to that reovired of the fire t.a rrie r. Penetrations are cualifies to meet the requirements of ASTM E-119, and IEEE Std. 634-1978; The actaal fire ratings cf stops and penetrations is ceterintned by the fire hazarcs analysis. Fire stops, fire barriers, and air seals will be constructed of mastic type materials or elastomer modular construction materials ocalifted in accorcance with IEEE Sta. 634 and ASTM E-119. Fire stop/ seal :r.aterial will be compatible with insulation ~and conductor materials and will be sheck, vibration, seismic, and raciation resistant in accorcance with the area (s) penetrated. =. E. Physical $eceration Criteria fer Cables of Cists IE Systems V The separation oesign cescription for raceways, Class 1E circuitry and associated cabling given below incorporates the recuirements of IEEE 5td. 364-1974 Regulatory Gaice 1.6 anc NRC Regulatcry Guice 1.75. ~ Lead groups, cables, and rateways of a safety-related system will be separated from iced greves, caoles. or race ays of etner safety-related groups in accorcance with the secaration criteria cescribec herein. This separation criteria will precluce a single failure within the safety-related system frora preventing procer protective action at the system level when required. Race ays anc cables will De classifice by separation groups, namely Class IE Division 1. Class IE Division 2. Class IE Division 3, and Plant Prctection System. ~ Cables cesignatec in each civision will be run in raceways separated from cables designates in otner civisiors and from Non-Class IE caoles. Associatec cables will be secaratec as if they were Class IE purscant to the Class 1E civision associatec.ith these cables. Amend 63 Dec. ;581 E.3 36 Y 3-- 2)fvtadno I,2 w 3 Q.M T cou. 7 yz % S -{. W% mada I m
8.3.3.3 NRC COMMENT h( Conduits as Fire Barriers y n SEption 8.3 1.1.2.1 of the PSAR states that " Cables rf the 4 division 3 power supply are separated from cables of the re-maining Class lE plant ac power supplies by routing them in conduits or cable trays in separate fire hazard areas". Based on this statement it appears that conduits will be used as a fire barrier for protecting division 3 cables. Clarification of this use of conduits will be pursued with the applicant and the results of our evaluation will be reported in a supplement to this report.
RESPONSE
The conduits are not used as a fire barrier for protecting division 3 cables. The conduits and cable trays are used as raceways for routing of Class 1E division 3 cables. The cables and raceways of the Class 1E division 3 power supply are separated from other Class lE divisions in accordance with the criteria described in the Section 8.3.1.4 of the PSAR and response to question CS430,10, forwarded by letter of June 1, 1982. W m 8 3 3 3 -Il
8.3.3.3 NRC COMMENT i) Protection of Class lE Cables from Rotating or Dropped Equipment b Sqparation between redundant raceways as defined in the PSAR takes into consideration the presence of rotating equipment, monorails, and equipment removal paths and the possibility that heavy equipment could be lifted and dropped and possibly cause failure of two race-way channels. The PSAR states that the minimum separation between two raceway channels at Clinch River will be such as to preclude failure of both channels. Current regulatory guidelines, however, requires protection of each raceway as well as separation so that the dropped equipment will not cause failure of either raceway. An alternative to protection may b_ a design that provides an additional two independent systems each capable of shutting down the reactor and separated cuch that neither will be affected by the " dropped equipment" or failure of rotating equipment. By letter dated June 1, 1982, the applicant indicated that rou' of safety-related raceways will be such that any dropped et. will not result in a failure of any safety-related raceway. staff concludes that safety related raceways will be protectea from droppped equipment, meets review guidelines, and is acceptable. Also, by letter dated June 1, 1982, the Applicant stated that the safety system design includes three divisions each capable of shutting down the reactor and each located such that failure of rotating equipment will not cause fa.ilure of more than one safety division. This statement is unclear as to the rotating equipment that has failed. Clarifications will be pursued with the applicant and in coordination with ASB the results will be reported in a supplement to this report.
RESPONSE
The terminology " rotating equipment" contained in response to
~ 8.3.3.3 NRC COMMENT (Continued) 1 qpestion CS430.14, (See Letter dated June 1,1982) inctudes motors, dieselgeneratorgfansrelatedtothesameClass1Edfvisionas ( tye cables affected by the failure of rotating equipment. The failure of these rotating equipment may cause failure of only one Class lE division. The remaining two Class lE load groups which are individually capable to safety shutdown the plant will not be affected. All non-safety related equipment located in Seismic Category I buildings are designed to maintain structural integrity under a Seismic event and will not become missiles. E m 8.3.3.3-13
L 8.3.3.5.1 IUC C N C E 1 e Teisting of Circuit Breakers 4 Seban 8.3.1.1.2 of the PSAR (under the subheading " Testing and Inspection") implies that when 4.16 kv and 480 V swit6 gear circuit breakers are being tested, their capability to respnd to a bcna fide signal dering operation has not been maintained in accordance with guidelines of Section 5 of IEEE Standard 338-1977. By letter dated June 1,1982, the applicant has further implied that the subject breakers are not designed in accordarce with the guidelines of Section 5 of Tm Standard 338-1977, to be functionally tested during operatian of the nuclear p&er generating station. Justification for noncompliance will be pursued with the applicant and the results of the staff evaluation will be reported 2.n a supplerent to this report. RESP 2EE ':he Class lE electrical distribution system consists of Mree functionally redundant safety divisions, as desenbed in Section 8.3.1 of the PSAR, any of which has the capability to safely shutoown the plant. Circuit breakers of ea6 of the three safety divisions are designed to be testable during plant operation as well as during plant shutd:xn. 'lhe testing will dronstrate the e
8.3.3.5.1 (continued) 1: -? a fd functional capability of the equipment under test. 7te equipment being tested will not cause a loss of in&pendence between redundant channels or load groups. As such, there is sufficient rehrf within the system to provide all necessary functions during testing, even when degra&d b a / single rand s failure. E e
8.3.3.4 EEC Comment Compliance With the Guidelines nf NUREG-0737. " Clarification nf IH1 Action Plan Requirements" p Two kMI items relating to GDC 17 are identified in NUREG-b737. These item are II.E.3.1, Emergency Power Supply for Pressurizer Heaters, and II.G.1, Emergency Power f or Pressurizer Equipment. The background, the NUREG position, and clarification of the positions are included in the NUREG report. This item will be pursued with the applicant and the results reported in a supplement to this repor t. Rerponse The CRBRP's evaluscion and resolution of TMI Action Plan Requirements are contained in Appendix H of the PSAR. Specific information concerning items II.E.3.1 and II.G.1 are included in Appendix H. E}}