ML20086J348
| ML20086J348 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/10/1995 |
| From: | DUQUESNE LIGHT CO. |
| To: | |
| Shared Package | |
| ML20086J340 | List: |
| References | |
| NUDOCS 9507190033 | |
| Download: ML20086J348 (123) | |
Text
{{#Wiki_filter:~ DPR-66 INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.0 APPLICABILITY , . . . . . . .......... 3/4 0-1 3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 BORATION CONTROL 3/4.1.1.1 Shutdown Margin - Tavg > 200*F . . . . 3/4 1-1 3/4.1.1.2 Shutdown Margin - T avg i 200*F , . . . 3/4 1-3 3/4.1.1.3 Boron Dilution . . . .......... 3/4 1-4 3/4.1.1.4 Moderator Temperature Coefficient . . . 3/4 1-5 3/4.1.1.5 Minimum Temperature for Criticality . . . 3/4 1-6 3/4.1.2 BORATION SYSTEMS 3/4.1.2.1 Flow Paths - Shutdown . . . . . . . . . . 3/4 1-7 3/4.1.2.2 Flow Paths - Operating . . . . . . . . . 3/4 1-9 3/4.1.2.3 Charging Pump - Shutdown . . . . . . . . 3/4 1-11 3/4.1.2.4 Charging Pumps - Operating . . . . . . . 3/4 1-12 3/4.1.2.5 Boric Acid Transfer Pumps - Shutdown . . 3/4 1-13 3/4.1.2.6 Boric Acid Transfer Pumps - Operating . . 3/4 1-14 3/4.1.2.7 Borated Water Sources - Shutdown . . . . 3/4 1-15 3/4.1.2.8 Borated Water Sources - Operating . . . . 3/4 1-16 5/if, I , p . cf Ysolah;,t e f u,, ni ,, y wg ge vm s a gy g + g e w ,7 g,<j t - t k 3/4.1.3 MOVABLE CONTROL ASSEMBLIES 3/4.1.3.1 Group Height . . . . .......... 3/4 1-18 3/4.1.3.2 Position Indication Systems - Operating . 3/4 1-20 3/4.1.3.3 Position Indication System - Shutdown . . 3/4 1-21 3/4.1.3.4 Rod Drop Time . . . . .......... 3/4 1-22 3/4.1.3.5 Shutdown Rod Insertion Limit . . . . . . 3/4 1-23 3/4.1.3.6 Control Rod Insertion Limits . . . . . . 3/4 1-23A BEAVER VALLEY - UNIT 1 IV Amendment No. -4M-9507190033 DR 950710 ADOCK 05000334 PDR q{'repoi.co0 LOWd 'q ) 1
DPR-66 INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS 3/4.4.1.1 Normal Operation . . . . . ....... 3/4 4-1 3/4.4.1.2 Hot Standby . . . . . . . . ....... 3/4 4-2b 3/4.4.1.3 Shutdown . . . . . . . . . ....... 3/4 4-2c 3/4.4.1.4.1 I;;l;t;d Loop T8r.'aM? D Y#'# . . ..... 3/4 4-3 3 / 4/. 4. f . 4 2 Loop .r s ole t, o ,, V. Le s - s h dJ a w. 3/ V V-J % 3/4.4.1.5 Isolated Loop Startup . . . ....... 3/4 4-4 I 3/4.4.1.6 Reactor Coolant Pump Startup ...... 3/4 4-4a 3/4.4.2 SAFETY VALVES - SHUTDOWN . ....... 3/4 4-5 3/4.4.3 SAFETY VALVES - OPERATING . ....... 3/4 4-6 3/4.4.4 PRESSURIZER . . . . . . . . ....... 3/4 4-7 3/4.4.5 STEAM GENERATORS . . . . . ....... 3/4 4-8 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE 3/4.4.6.1 Leakage Detection Instrumentation . ... 3/4 4-11 3/4.4.6.2 Operational Leakage . . . . ....... 3/4 4-13 3/4.4.6.3 Pressure Isolation Valves . ....... 3/4 4-14a 3/4.4.7 CHEMISTRY . . . . . . . . . ....... 3/4 4-15 3/4.4.8 SPECIFIC ACTIVITY . . . . . ....... 3/4 4-18 3/4.4.9 PRESSURE / TEMPERATURE LIMITS 3/4.4.9.1 Reactor Coolant System . . ....... 3/4 4-22 I I ) BEAVER VALLEY - UNIT 1 VI Amendment No des-( fr e f e3ed Wd *))
i DPR-66 REACTIVITY CONTROL SYSTEMS } ISOLATION OF UNBORATED WATER SOURCES - SHUTDOWN ; LIMITING CONDITION FOR OPERATION ( 3.1.2.9 The following valves shall be locked, sealed or otherwise i secured in the closed position except during planned boron dilution i or makeup activities.
- a. 1CH-90, or '
- b. 1CH-91 and 1CH-93 i
APPLICABILITY: MODES 4, 5 and 6. ACTION: With the requirements of the above specification not satisfied, I perform the following: '
- 1. Immediately suspend all operations involving positive !
reactivity changes, CORE ALTERATIONS or any use of the ' Primary Grade Water System with the Charging System, ,
- 2. Immediately initiate actions to lock, seal or otherwise .
secure the required valve (s) in the closed position as soon ( as possible, and i I
- 3. Verify within 1 hour W that the SHUTDOWN MARGIN is greater i than or equal to the minimum required as per the applicable !
specification listed below and follow the applicable , specification ACTIONS as necessary* t i Soecification Apolicable MODE j l 3.1.1.1 4 j 3.1.1.2 5 t 3.9.1 6 SURVEILLANCE REQUIREMENTS , l 4.1.2.9 The above listed valve (s) shall be verified to be locked, i sealed or otherwise secured in the closed position: ! l
- a. Within 15 minutes after a planned boron dilution or makeup l activity, and I
- b. At least once per 31 days.
(1) This action is required to be completed regardless of when the requirements of the above specification are satisfied. BEAVER VALLEY - UNIT 1 3/4 1-17a Amendment No. (Proposed Wording)
DPR-66 i TABLE 3.3-1 (Continued) ACTION 4 - With the number of channels OPERABLE one less than , required by the Minimum Channels OPERABLE requirement 4 and with the THERMAL POWER level: I
- a. Below P-6, restore the inoperable channel to OPERABLE !
status prior to increasing THERMAL POWER above the P-6 i setpoint.
- b. Above P-6, operation may continue. f ACTION 5 - With the number of channels OPERABLE one less than f' required by the Minimum Channels OPERABLE requirement, verify compliance with the SHUTDOWN MARGIN :
requirements of Specification 3.1.1.1 or Specification 3.1.1.2, as applicable within 1 hour, and at least once per 12 hours thereafterm .a ver.Q vsives (ic M- 90) e (lcy.qg ,,,,,yeg.9y) ,,,,,y,,qg A ACTION 6 - Not Applicable. M e u r*4 A go,iu a u g , % j, , ,, - ACTION 7 - With the number of OPERABLE channelsW one less than ! the Total Number of Channels, STARTUP and/or POWER OPERATION may proceed provided the following l conditions are satisfied *
- a. The inoperable channel is placed in the tripped condition within 6 hours, and !
- b. The Minimum ' Channels OPERABLE requirement is met; f however, the inoperable channel may be bypassed for up !
to 4 hours for surveillance testing of other channels > per Specification 4.3.1.1.1. i l ACTION 8 - With the number of OPERABLE channels one less than the Total Number of Channels and with the THERMAL POWER i level above P-7, place the inoperable channel in the tripped condition within 6 hours; operation may continue until performance of the next required CHANNEL FUNCTIONAL TEST. ACTION 9 - Not applicable. ACTION 10 - Not applicable. (4) An OPERABLE hot leg channel consists of: 1) three RTDs per hot leg, or 2) two RTDs per hot leg with the failed RTD disconnected and the required bias applied. BEAVER VALLEY - UNIT 1 3/4 3-6 Amendment No464-( Pret* sed Wca % ) }
l DPR-66 I 3/4.4 REACTOR COOLANT SYSTEM l i 1 3/4.4.1 REACTOR COOLANT LOOPS I I 1 I NORMAL OPERATION i i LIMITING CONDITION FOR OPERATION 3.4.1.1 All reactor coolant loops shall be in operation. , 1 APPLICABILITY: MCDES 1 and 2%. l ACTION: _ _ . ... .. m _ _ , , _ _ _ . _ _ - - . _ _ om._... . - .wv v e r ,, uvmpty -ivu .tuu.& w . mu. .w vuu3 . . . .
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l i DPR-66 l 1 REACTOR COOLANT SYSTEM l l ACTION (Continued) ; i i Place the following reactor trip system channe , I associated with the lo not in operation in j heirtrippedconditions:pp l
- 1) Overpower AT channel.
- 2) O rtemperature AT channel. ;
i c) Change th P-8 interlock setpoi from the value : specified in Table 2.2-1 to: i
- 1) s 71% o RATED TH L POWER when the !
reactor c lant op valves in the nonoperating 1 pa closed, or
- 2) s 66% of RAT THERMAL POWER- when the reactor coo nt stop valves in the ;
nonoperating oop are en. !
- 2. THERMAL POWER is re ricted to: ,
a) S 66% of RATED THERMAL POWER en the reactor ; coolant top valves in the nonope ting loop are :' closed or b) s % of RATED THERMAL POWER when th reactor c lant stop valves in the nonoperating 1 p are pen. I 9 t
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l l BEAVER VALLEY - UNIT 1 3/4 4-2 Amendment No. 4NA l 1 LPc.nsa ww.fj l
DPR-66 , REACTOR COOLANT SYSTEM ACTION (Continued) o,-..
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DPR-66 REACTOR COOLANT SYSTEM
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LOOP ISOLATION VALVES - OPERATING LIMITING CONDITION FOR OPERATION 3.4.1.4.1 Each RCS hot and cold leg loop isolation valve shall be open with power removed from each isolation valve operator. APPLICABILITY: MODES 1, 2, 3 and 4. ACTION:
- a. With one or more RCS loop isolation valve (s) closed, maintain the valve (s) closed, be in MODE 3 within the next 6 hours, and be in MODE 5 within the following 30 hours,
- b. With power available to one or more loop isolation valve operators, remove power fr the loop isolation valve operators within 30 minutes. (gm)
SURVEILLANCE REQUIREMENTS 4.4.1.4.1 Verify at least once per 31 days that each RCS loop isolation valve is open and power is removed from each isolation valve operator. (1) Separate Condition entry is allowed for each RCS loop isolation valve. BEAVER VALLEY - UNIT 1 3/4 4-3 Amendment No. (Proposed Wording)
DPR-66 7 REACTOR COOLANT SYSTEM ^ ICCUTEC LOOP r$O L A TIoM VALVE.S - S H UT b0 a 10 I LIMITING CONDITION FOR OPERATION I lesr Isolu & Va\v's 'h *** h*4'0 E E**P i
- 3. 4.1. 4.1 The , P.CS i=01sted 100; t p ve I from the associated galve operatorsV.0) lves shall have power removed l loop isdaW \
APPLICABILITY: ; HovEs - Whenever an RCS loop has bee,n isolated, Mcd;; 5 and 6(. g l l f ACTION: With the requirements of the above specification not satisfied, ' remove power from the isolated loop etep- valve operators ( within 1 . hour. isel=6ea (') i l l SURVEILLANCE REQUIREMENTS 4.4.1.4.RVerify at least once per 7 days that power is removed from the RCS isolated loop -etop- valve operatorsW.0/ l , Isolah 's l o'seta & r 'd0) Power may be restored to the associated RCS isolated 1 pop =tep I valve operators provided the requirements of /2rveillance
/hquirement 4.4.1.5.+ have been satisfied.
JZ. (4} With fuel in the vessel. l BEAVER VALLEY - UNIT 1 3/4 4-3q Amendment 54-CPre rose A W ed hy]
DPR P REACTOR COOLANT SYSTEM l ISOLATED LOOP STARTUP s LIMITING CONDITION FOR OPERATION 1 l 3.4.1.5 The RCS cold leg stop valve shall remain closed until: l
- a. The isolated loop has been operating on a recirculation !'
flow of 2 125 gpa for at least 90 minutes and the f temperature at the cold leg of the isolated loop is within j 20*F of the highest cold leg temperature of the operating ! loops.
- b. The reactor is subcritical by at least 1 percent Ak/k. [
- c. The isolated loop boron concentration is greater than or equal to the minimum required to satisfy the applicable j
. requirements of . specification 3.1.1.2 for Mode 5 or Specification 3.9.1 for Mode 6.
APPLICABILITY: MODES 5 and 6*. l l ( i ACTION: ; With the requirements of the above specification not satisfied, I suspend startup of the isolated loop. , 1 SURVEILLANCE REQUIREMENTS 4.4.1.5.1 The isolated loop cold leg temperature shall be determined to be within 20*F of the highest cold leg temperature of i the operating loops within 30 minutes prior to opening the cold leg ! stop valve. 4.4.1.5.2 The reactor shall be determined to be subcritical by I at least 1 percent Ak/k within 30 minutes prior to opening the cold leg stop valve. 4.4.1.5.3 The isolated loop boron concentration shall be determined to be greater than or equal to the minimum required to satisfy the applicable requirements of Specification 3.1.1.2 for Mode 5 or Specification 3.9.1 for Mode 6 within 30 minutes prior to opening the hot leg stop valve and again within 30 minutes prior to opening the cold leg stop valve.
- With fuel in the vessel.
BEAVER VALLEY - UNIT 1 3/4 4-4 Amendment No. 150 Se plac.c. MM 'C 6 s e-r f /}
1 DPR-66 l REACTOR COOZ. ANT SYSTEM 54(f/)) ISOLATED LOOP STARTUP LIMITING CONDITION FOR OPERATION ; 3.4.1.5 Each RCS isolated loop shall remain isolated with:
- a. The hot and cold leg isolation valve closed until the isolated portion of the loop has been drained and refilled from the Refueling Water Storage Tank or Reactor Coolant System, and
- b. The hot and cold leg isolation valvas closed if the boron concentration in the isolated loop is less than the minimum required to satisfy the applicable requirements of Specification 3.1.1.2 for MODE 5 or Specification 3.9.1 for MODE 6. l APPLICABILITY: Whenever an RCS loop has been isolated greater than 4 hours or drained (l) . l ACTION:
With the requirements of the above specification not satisfied, immediately close the hot and cold leg isolation valves. SURVEILLANCE REQUIREMENTS 4.4.1.5.1 Verify that the isolated loop has been drained and refilled with water from the Refueling Water Storage Tank or Reactor Coolant System prior to opening the hot or cold leg isolation valve in the isolated loop. l I 4.4.1.5.2 Verify that the isolated loop boron concentration is l l greater than or equal to the minimum required to satisfy the 1 applicable requirements of Specification 3.1.1.2 for MODE 5 or l Specification 3.9.1 for MODE 6 within 2 hours prior to opening the hot or cold leg isolation valve in the isolated loop. 4.4.1.5.3 Verify that the hot or cold leg isolation valve in the isolated loop is opened within 4 hours following completion of refilling the isolated loop. i (1) With fuel in the vessel. ; l BEAVER VALLEY - UNIT 1 3/4 4-4 Amendment No. ! (Proposed Wording) j l
c DPR-66 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.2 BORATION SYSTEMS (Continued) The required volume of water in the refueling water storage tank for reactivity considerations while operating is 424,000 gallons. The associated technical specification limit on the refueling water storage tank has been established at 441,100 gallons to account for reactivity considerations and the NPSH requirements of the ECCS system. ; l The OPERABILITY of the RWST as part of the ECCS ensures that a j sufficient supply of borated water is available for injection by the l ECCS in the event of a LOCA. The limits on RWST minimum volume and boron concentration ensure that 1) sufficient water is available within containment to permit recirculation cooling flow to the core, and 2) the reactor will remain suberitical in the cold condition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the most reactive control assembly. These assumptions are consistent with the LOCA analysis. 1 The limitations for a maximum of one centrifugal charging pump to be l OPERABLE and the Surveillance Requirement to verify all charging pumps except the required OPERABLE pump to be inoperable / the l enable temperature set forth in Specfication 3.4.9.3 provi %de assurance that a mass addition pressure transient can be relieved by } the operation of a single PORV. Substituting a Low Head Safety l Injection pump for a charging pump in Modes 5 and 6 will not ' increase the probability of an. overpressure event since the shutoff [ head oftheLowHeadSafetyInjectionpumpsisgthesetpointofthe) l overpressure protection system. ( - l Add l~nserf 8 -> l l i BEAVER VALLEY - UNIT 1 B 3/4 1-2a Amendment No. 444L (Prcjvscs ved;g
Insert B Isolation of the primary grade water flow path during MODES 4, 5 and 6 precludes an unplanned boron dilution at these conditions since the sole source of unborated water to the charging pumps is isolated. This eliminates the design basis boron dilution event in MODES 4, 5 and 6. During planned boron dilution events, operator attention will be focused on the boron dilution process and any inappropriate blender operation would be readily identified through various indications which includes the output from the source range nuclear instrumentation. Closing either a) 1CH-90, or b) 1CH-91 and 1CH-93 will ensure that all possible flow paths are isolated from the Primary Grade Water System to the operating Reactor Coolant System flow path via the charging pumps, thus preventing any potential inadvertent boron dilution event by injection of unborated water. The ACTION to suspend all operations involving positive reactivity changes or CORE ALTERATIONS is intended to provide assurance that no other activity will mask any potential unintentional boron dilution event. Maintaining the Primary Grade Water System isolated is necessary to ensure that the design basis boron dilution event is not credible. Thus, immediate corrective action is needed to restore positive isolation as soon as possible when not conducting planned boron dilution or makeup activities. Lack of continuous corrective action to restore the Limiting Condition For Operation (LCO) would then make a potential inadvertent boron dilution credible and require performing additional analysis to verify acceptable consequences if it should occur. Verifying the SHUTDOWN MARGIN within one hour ensures that no unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. The SHUTDOWN MARGIN need only be verified once since the cessation of any activities involving positive reactivity changes, CORE ALTERATIONS or use of the Primary Grade Water System with the Charging System will prevent any future potential injection of Primary Grade Water into the Reactor Coolant System. The verification of SHUTDOWN MARGIN needs to be completed anytime that the ACTION is entered even if the LCO is subsequently satisfied before the verification is completed to ensure that no unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. The primary function of the surveillance is to ensure that the valve (s) used to isolate the Primary Grade Water System are locked, sealed or otherwise secured. The frequency of 31 days to ensure that the Primary Grade Water System is properly isolated is based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 31 day frequency is justified. A time frame of 15 minutes provides a minimum reasonable time for an operator to isolate the Primary Grade Water System following a planned activity requiring its use.
DPR-66 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1,q3.3 REACTOR COOLANT LOOPS The plant is designed to operate with all reactor coolant loops in ) operation and maintain DNBR above the design DNBR limit during all normal operations and anticipated transients. In Modes 1 and 2, with one reactor coolant loop not in operation, THERMAL POWER is restricted to less than or equal to 31 percent of RATED THERMAL POWER until the Overtemperature AT trip is reset. Either action ensures ! that the DNBR will be maintained above the design DNBR limit. A loss of flow in two loops will cause a reactor trip if operating above P-7 l (11 percent of RATED THERMAL POWER) while a loss of flow in one loop ' will cause a reactor trip if operating above P-8 (31 percent of RATED ' THERMAL POWER). In MODE 3, a single reactor coolant loop provides sufficient heat removal capability for removing decay heat; however, due to the initial conditions assumed in the analysis for the control rod bank i withdrawal from a suberitical condition, two operating coolant loops I are required to meet the DNB design basis for this Condition II l event. j In MODES 4 and 5, a single reactor coolant loop or RHR subsystem , provides sufficient heat removal capability for removing decay heat; l but single failure considerations require that at least two loops be OPERABLE. Thus, if the reactor coolant loops are not OPERABLE, this specification requires two RHR loops to be OPERABLE. ! l The operation of one Reactor Coolant Pump or one RHR pump provides adequate flow to ensure mixing, prevent stratification and produce l gradual reactivity changes during boron concentration reductions in j the Reactor Coolant System. The reactivity change rate associated I with boron reduction will, therefore, be within the capability of operator recognition and control. The restrictions on starting a Reactor Coolant Pump with one or more RCS cold legs less than or equal to 275'F are provided to prevent RCS pressure transients, caused by energy additions from the secondary system, which could exceed the limits of Appendix G to 10 CFR Part
- 50. The RCS will be protected against overpressure transients and will not exceed the limits of Appendix G by either (1) restricting the water level in the pressurizer and thereby providing a volume for the primary coolant to expand into or (2) by restricting starting of the RCPs to when the secondary water temperature of each steam generator is less than 25'F above each of the RCS cold leg 4 temperatures.
"cucr is ccmoved from the icciated 100p Otop "21"c0 (het leg a".d celd ;
leg) te ensure thet no resctivity addition to the 00re ca." l C w.: m ac BEAVER VALLEY - UNIT 1 B 3/4 4-1 Amendment No. 173 ( Pr t c.u d cJ o d 'Ag )
Insert C Page 1 of 6 3/4.4.1.4 LOOP ISOLATION VALVES BACKGROUND The RCS may be operated with loops isolated in order to perform maintenance. While operating with a loop isolated, there is a potential for inadvertently opening the isolation valves in the isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. This situation has the potential for causing a positive reactivity addition with a corresponding reduction of SHUTDOWN MARGIN if the boron concentration in the isolated loop is less than the required SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriate sudden positive reactivity addition from unborated water because: a . LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating loops below the required SHUTDOWN MARGIN; and
- b. The loop isolation valves cannot be opened unless the loop has been drained and refilled with water supplied from the Refueling Water Storage Tank or from the Reactor Coolant System. This would include water from the refueling cavity.
This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless specifically intended by a procedure.
APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance with the NRC SER on N-1 loop operation. During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop isolation valve until the isolated loop is drained and refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System, and the isolated loop boron concentration is verified. Verification of the isolated loop boron concentration prior to opening the isolated loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity effect from the isolated loop does not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design __ =
l Insert C Page 2 of 6 Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety analyses. LCO LCO 3.4.1.4.1 ensures that a loop isolation valve that becomes closed in MODES 1 through 4 is fully closed and the plant placed in MODE 5. LCO 3.4.1.4.2 ensures that power is removed from isolated loop isolation valve operators when closed to perform maintenance in MODES S or 6 to prevent an inadvertent loop startup. APPLICABILITY LCO 3.4.1.4.1 is applicable in MODES 1 through 4 and LCO 3.4.1.4.2 is applicable whenever an RCS loop has been isolated in MODES 5 and 6 with fuel in the reactor vessel. LCO 3.4.1.4.2 is not applicable when there is no fuel in the reactor vessel. In MODES 5 and 6, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS loop is considered isolated in MODES 5 and 6 whenever the hot and cold leg isolation valves on one RCS loop are both in a fully closed position at the same time. One isolation valve may be stroked for testing in MODES 5 and 6 and the loop will not be considered isolated when either the hot leg or cold leg loop isolation valve remains open. ACTION For LCO 3.4.1.4.1 au Should a loop isolation valve be closed in MODES 1 through 4, the affected loop isolation valve (s) must be maintained closed and the plant placed in MODE 5 to preclude inadvertent startup of the loop and the subsequent potential inadvertent positive reactivity insertion or criticality. The Completion t ' Time of the ACTIONS allow time for borating the operating loops to a shutdown boration level such that the plant can be brought to MODE 3 within 6 hours and MODE 5 within 36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. b_,_ I f power is inadvertently restored to one or more loop isolation valve operators, the potential exists for accidental isolation of a loop with a subsequent inadvertent ! startup of the isolated loop. The loop isolation valves have motor operators. Therefore, these valves will maintain their
1 l Insert C Page 3 of 6 last position when power is removed from the valve operator. With power applied to the valve operators, only I administrative controls prevent the valve from being l operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to remove power t i from the loop isolation valve operators. The Completion Time ; i of 30 minutes to remove power from the loop isolation valve ; operators is sufficient considering the complexity of the ! task. I l l For LCO 3.4.1.4.2 j If power is inadvertently restored to one or more loop isolation ! valve operators, the potential exists for accidental isolation of a . loop with a subsequent inadvertent startup of the isolated loop. l The loop isolation valves have motor operators. Therefore, these j valves will maintain their last position when power is removed from i the valve operator. With power applied to the valve operators, only i administrative controls prevent the valve from being operated. > l Although operating procedures make the occurrence of this event I unlikely, the prudent action is to remove power from the loop I isolation valve operators. The Completion Time of 1 hour to remove power from the loop isolation valve operators is sufficient considering the complexity of the task. SURVEILLANCE REOUIREMENTS (SR) SR 4.4.1.4.1 , SR 4.4.1.4.1 is performed at least once per 31 days to ensure that the RCS loop isolation valves are open, with power removed from the loop isolation valve operators. The primary function of this surveillance is to ensure that power is removed from the valve operators, since SR 4.4.1.1 ensures that the loop isolation valves are open by verifying every 12 hours that all loops are operating and circulating reactor coolant. The frequency of 31 days ensures that the required flow can be made available, is based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 31 day l frequency is justified. l l SR 4.4.1.4.2 SR 4.4.1.4.2 is performed at least once per 7 days to ensure that the RCS loop isolation valves have power removed from the loop isolation valve operators. The frequency of 7 days which ensures that the power is removed from loop isolation valve operators, is i based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 7 day frequency is justified. l
1 Insert C Page 4 of 6 3/4.4.1.5 ISOLATED LOOP STARTUP BACKGROUND The RCS may be operated with loops isolated in order to perform maintenance. While operating with a loop isolated, there is a potential for inadvertently opening the isolation valves in the isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. This situation has the potential for causing a positive reactivity addition with a corresponding reduction of SHUTDOWN MARGIN if the boron concentration in the isolated loop is less than the required SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriata sudden positive reactivity addition from unborated water because: a . LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating loops below the required SHUTDOWN MARGIN; and
- b. The loop isolation valves cannot be opened unless the loop has been drained and refilled with water supplied from the Refueling Water Storage Tank or from the Reactor Coolant System. This would include water from the refueling cavity.
This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless specifically intended by a procedure.
APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance with l the NRC SER on N-1 loop operation. During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop isolation valve until the isolated loop is drained and refilled with water supplied I from the Refueling Water Storage Tank or Reactor Coolant System, and l the isolated loop boron concentration is verified. Verification of l the isolated loop boron concentration prior to opening the isolated i loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity effect from the isolated loop does not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design
Insert C Page 5 of 6 l Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety analyses. l LCQ l Loop isolation valves are used for performing maintenance when the plant is in MODES 5 or 6. LCO 3.4.1.5 ensures that the loop , isolation valves remain closed on an isolated loop until the ! SHUTDOWN MARGIN in the isolated loop is within acceptable limits. l APPLICABILITY j In MODES 5 and 6, the SHUTDOWN MARGIN of the operating loops is ! large enough to permit operation with isolated loops. In these l MODES, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS loop is considered isolated in MODES 5 and 6 whenever the hot , and cold leg isolation valves on one RCS loop are both in a fully closed position at the same time. One isolation valve may be f stroked for testing in MODES 5 and 6 and the loop will not be ? I considered isolated when either the hot leg or cold leg loop l isolation valve remains open. l l l ACTION I l The ACTION for LCO 3.4.1.5 assumes that the prerequisites of the LCO l are not met and a loop isolation valve has been inadvertently l opened. Therefore, the ACTION requires immediate closure of l isolation valves to preclude a potential boron dilution event. l l SURVEILLANCE REOUIREMENTS (SR) SR 4.4.1.5.1 and 4.4.1.5.3 As an additional measure to ensure that the boron concentration in an isolated loop remains within acceptable limits, SR 4.4.1.5.1 requires that an isolated loop is drained and refilled with borated water supplied from the Refueling Water Storage Tank or Reactor Coolant System prior to opening the hot or cold leg isolation valve in the isolated loop. The 4 hour time limit ensures that there is no unacceptable boron concentration stratification in an isolated loop. These surveillance frequencies have been shown to be acceptable through operating experience.
l l Insert C Page 6 of 6 . SR 4.4.1.5.2 To ensure that the boron concentration of the isolated loop meets acceptable limits, SR 4.4.1.5.2 is performed within 2 hours prior to opening either the hot or cold leg isolation valve. This provides reasonable assurance that the boron concentration will stay within acceptable limits until the loop is unisolated. l l l f I s i l i l 1
DPR-66 . 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1 REACTOR COOLANT LOOPS, (continued)
-occur while the 100; ic inclated due te inadvertent cp ninj cf the
-ieetat;d locp ctcp /clvec. Icclated 100; ctartup ic limited te ."cdec
~5 and 5 in acccrdance with the NRC CER cn N-1 locp sp;rction.
-Verificatier Of the inclated 100p berer cencentration prier tc cpening the icolated 100; ctcp /civec previdec reaccurance Of th:
.adeguacy of the chutdcer m:rgin in thc rescinder cf the syst..m.
-Rester tier Of peu:r tc the het leg ctcp valv: 0110w cp;ning this valv; to compl:t; th; r;;irculation ficupath in conjunction with th;
. relief line byparring the celd leg Otcp /alv and :nsures adequate
-mixing in the ieclated leep. This enables the temperature and berer
-ecnc;ntration of the icolated loop tc be brought to equilibrium with the r===inder of the cyctcc. Limiting the t perature differentiel betueen the isolated 100p :nd the rencinder Of th cyctc= pri. h an=ning *ha cold leg step valve prevent: :ny cignificant reactivity
-ef-f4 cts-due-te c001 water-addi+ ion-to-the-core.
-startup cf an idle leep vill inject ceci ester frer the Icep into the core. The rc:ctivity transient resulting ficm thi. vvvi w a t er-injecticn ic minimized by delcying iscist:d loop startup until its
-te=perature ic within 20 " of the cpereting leep . Lkluy i.b c j -reacter subcritical prier te lecp ct:rtup preventc any pcuer spike which could recult from this ccel w&toi tuduvad t eaviivity transient.
3/4.4.2 and 3/4.4.3 SAFETY VALVES l The pressurizer code safety valves operate to prevent the RCS from i being pressurized above its Safety Limit of 2735 psig. Each safety valve is designed to relieve 345,000 lbs. per hour of saturated steam at the valve set point. The relief capacity of a single safety valve is adequate to relieve any overpressure condition which could occur during shutdown. In the event that no safety valves are OPERABLE, an operating RHR loop, connected to the RCS, provides overpressure relief capability and will prevent RCS overpressurization. During operation, all pressurizer code safety valves must be OPERABLE to prevent the RCS from being pressurized above its safety limit of 2735 psig. The combined relief capacity of all of these valves is greater than the maximum surge rate resulting from a complete loss of load assuming no reactor trip until the first Reactor Protective System trip set point is reached (i.e., no credit is taken for a direct reactor trip on the loss of load) and also assuming no operation of the power operated relief valves or steam dump valves. BEAVER VALLEY - UNIT 1 B 3/4 4-la Amendment No. 1M ( Pro f Csed W cd
1 I ATTACHMEliT A-2 Beaver Valley Power Station, Unit No. 2 Proposed Technical Specification Cnange No. 95 The following is a list of the affected pages: Affected Pages: Index Page V 3/4 1-17 3/4 3-6 3/4 4-1 3/4 4-5 3/4 4-Sa (New) 3/4 4-6 3/4 9-1 B 3/4 1-4 B 3/4 4-1 I l
F~ NPF-73 ) INDEX LIMITING CONDITION FOR OPERATION AND SURVEILLANCE REOUIREMENTS !
' r l
SECTION PAG, 3/4.2.4 QUADRANT POWER TILT RATI0...................... ..... . .... 3/4 2-11 l 3/4.2.5 DNB PARAMETERS....................................... ...... 3/4 2-13 3/4.3 INSTRUMENTATION 3/4.3.1 REACTOR TRIP SYSTEM INSTRUMENTATION......................... 3/4 3-1 ; 3/4.3.2 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION. 3/4 3-14 3/4.3.3 MONITORING INSTRUMENTATION . Radiation Monitoring........................................ 3/4 3-39 Movable Incore Detectors.................................... 3/4 3-45 Seismic Instrumentation..................................... 3/4 3-46 . Meteorological Instrumentation.............................. 3/4 3-49 ; Remote Shutdown Instrumentatiors............................. 3/4 3-52 ; Chlorine Detection Systems.................................. 3/4 'a-56 ; Accident Monitoring Instrumentation......................... 3/4 3-57 Radioactive Liquid Effluent Monitoring Instrumentation...... 3/4 3-60 t Radioactive Gaseous Effluent Monitoring Instrumentation..... 3/4 3-65 . 3/4.3.4 TURBINE OVERSPEED PROTECTION................................ 3/4 3-74 , 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION Normal Operation........................................... 3/4 4-1 , i Hot Standby .................................... .......... 3/4 4-2 _ Shutdown .................................................. 3/4 4-3
' Reactor Coolant Pump-Startup .............................. 3/4 4-7 3/4.4.2 SAFETY VALVES - SHUTD0WN................................... 3/4 4-8 3/4.4.3 SAFETY VALVES - 0PERATING.................................. 3/4 4-9 3/4.4.4 PRESSURIZER................................................ 3/4 4-10 3/4.4.5 STEAM GENERATORS............................................ 3/4 4-11 l Loy Isda hin V adC - Crudsj - - - - -
. 3 /4 4- 7 i,q ru ta n v.us-su ac + {
.- . - - - . by y- s%
r s , s a r.t 4W wtW l
~ . . . . . - \
. . . 2,y 9 g; BEAVER VALLEY - UNIT 2 V L Propc>cJ twaQ)
NPF-73 REACTIVITY CONTROL SYSTEMS ISOLATION OF UNB0 RATED WATER SOURCES - SHUT 00WN LIMITING CONDITION FOR OPERATION 3.1.2.9 Provisions to limit flow capability from unborated water sources to the reactor coolant system to less than or equal to 85 gpm by means of a flow limiting orifice shall be OPERABLE. APPLICABILITY MODES 4 and 5. ACTION With the requirements of the above specification not satisfied immediately suspend all operations involving positive reactivity changes and, if within 1 hour the required SHUTDOWN MARGIN is not verified, initiate and continue boration as specified in Specification 3.1.1.1 for MODE 4 and 3.1.1.2 for MODE 5 until the SHUTDOWN MARGIN is restored. SURVEILLANCE REOUIREMENTS 4.1.2.9 The provisions to limit flow capability to less than or equal to 85 gpm from unborated water sources to the reactor coolant system shall be determined to be OPERABLE at least once per 31 days by verifying that valve 2CHS-37 is closed. I g q/o e e w in 3- se,+ 3> BEAVER VALLEY - UNIT 2 3/4 1-17
NPF-73 se rt D) REACTIVITY CONTROL SYSTEMS ISOLATION OF UNBORATED WATER SOURCES - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.9 The following valves shall be locked, sealed or otherwise secured in the closed position except during planned boron dilution or makeup activities:
- a. 2CHS-37 and 2CHS-828, or i
- b. 2CHS-91, 2CHS-96 and 2CHS-138 APPLICABILITY: MODES 4, 5 and 6.
ACTION: With the requirements of the above specification not satisfied, perform the following: !
- 1. Immediately suspend all operations involving positive reactivity changes, CORE ALTERATIONS or any use of the Primary Grade Water System with the Charging System,
- 2. Immediately initiate actions to lock, seal or otherwise secure the required valve (s) in the closed position as soon as possible, and
- 3. Verify within 1 hour W that the SHUTDOWN MARGIN is greater than or equal to the minimum required as per the applicable specification listed below and follow the applicable specification ACTIONS as.necessary:
Soecification Acolicable MODE 3.1.1.1 4 3.1.1.2 5 3.9.1 6 SURVEILLANCE REQUIREMENTS 4.1.2.9 The above listed valve (s) shall be verified to be locked, sealed or otherwise secured in the closed position:
- a. Within 15 minutes after a planned boron dilution or makeup activity, and
- b. At least once per 31 days.
(1) This action is required to be completed regardless of when the requirements of the above specification are satisfied. BEAVER VALLEY - UNIT 2 3/4 1-17 Amendment No. (Proposed Wording)
, - .- - - . . . ~ _ - . - -- .-
y: i i NPF-73 f TABLE 3.3-1 (Continued) , ACTION 4 - With the number of channels OPERABLE one less than required by the Minimum Channels OPERABLE requirement i and with the THERMAL POWER level: ,
- a. Below P-6, restore the inoperable channel to OPERABLE !
status prior to increasing THERMAL POWER above the P-6 i setpoint and suspend positive reactivity operations. l
- b. Above P-6, operation may continue.
l ACTION 5 - With the number of OPERABLE channels one less than the Minimum Channels OPERABLE requirement, restore the inoperable channel to OPERABLE status within 48 hours , or open the Reactor Trip System breakers, suspend all operations involving positive reactivity changes and ; verify galvespCHS-91 closed and secured in position ! within the next hour,. (
,atc HS-% J a c HS-13 8) ce ,
ACTION 6 - This Action is not used, p e gg.3 7 ,_,s pes / s . g;g) a re. , ACTION 7 - With the number of OPERABLE channelsN one less than the Total Number of Channels, STARTUP and/or POWER ; OPERATION may proceed provided the following conditions are satisfied:
- a. The inoperable channel is placed in the tripped ;
condition within 6 hours, and >
- b. The' Minimum channels OPERABLE requirement is met; l however, the inoperable channel may be bypassed for up to 4 hours for surveillance testing of other channels per Specification 4.3.1.1.1.
ACTION 8 - With the number of OPERABLE channels one less than the Total Number of Channels and with the THERMAL POWER i level above P-9, place the inoperable channel in the 1 tripped condition within 6 hours; operation may continue until performance of the next required CHANNEL FUNCTIONAL TEST. ACTION 9 - This Action is not used. ACTION 10 - This Action is not used. (4) An OPERABLE hot leg channel consists of: 1) three RTDs per hot leg, or 2) two RTDs per hot leg with the failed RTD disconnected and the required bias applied. BEAVER VALLEY - UNIT 2 3/4 3-6 Amendment No (Tro(-csed L(Jer$ l
NPF-73 - i 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION NORMAL OPERATION LIMITIMG CONDITION FOR OPERATION ! 3.4.1.1 All reactor coolant loops shall be in operation. APPLICABILITY: MODES 1 and 2. ACTION: With less than the above required reactor coolant loops in operation, be in at '.aast HOT STANOBY within 6 hours. SURVEILLANCF REQUIREMENTS 4.4.1.1)( All reactor coolant loops shall be verified in operation and circulat- I' ing reactor coolant at least once per 12 hours. l
?. ?.1.1. 0 Th; ;rr:r t: :::h f th: ":::t:r C : lent Sy:ter 1::; :te; v:!ve:
05:11 5: :r'":d t: 5: -- :d :t ! ::t :::: ; r 31 dry: dur' ; :;;r:ti: '-
"005S 1 :24 2.
BEAVER VALLEY - UNIT 2 3/4 4-1 ( Pro p osed We ~j) 2
NPF-73 REACTOR COOLANT SYSTEM
,a , a m. ...: __ __ __. _ , ,
d.'7+ A+7 \ u II a J .J )J E b 4 i 36 8.:.. bIvis . . .i l WiiN U I iJ eau b vagw.j S C (' l t~ C C LJ
- Sh [ n ci t* r f3 E c_ ) l~
e 4 l l BEAVER VALLEY - UNIT 2 3/4 4-5 V "f 'l ''"3]
NPF-73 ( T n a' r / O ' REACTOR COOLANT SYSTEM LOOP ISOLATION VALVES - OPERATING LIMITING CONDITION FOR OPERATION 3.4.1.4.1 Each RCS hot and cold leg loop isolation valve shall be open with power removed from each isolation valve operator. APPLICABILITY: MODES 1, 2, 3 and 4. ACTION:
- a. With one or more RCS loop iPalation valve (s) closed, maintain the valve (s) closed, bo in MODE 3 within the next 6 hours, and be in MODE 5 withir; the following 30 hours.
- b. With power available to one or , tore loop isolation valve operators, remove power fym the loop isolation valve operators within 30 minutes SURVEILLANCE REQUIREMENTS 4.4.1.4.1 Verify at least once per 31 days that each RCS loop isolation valve is open and power is removed from each isolation valve operator. i I
l l (1) Separate Condition entry is allowed for each RCS loop isolation valve. l l l BEAVER VALLEY - UNIT 2 3/4 4-5 Amendment No. (Proposed Wording) l l _ . - -
NPF-73 BEACTOR COOLANT SYSTEM (rnse-F'h LOOP ISOLATION VALVES - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.4.1.4.2 The loop isolation valves in an isolated RCS loop shall have power removed from the associated loop isolation valve operators (1) . APPLICABILITY: Whenever an RCS loop has been isolated, MODES 5 and 6(2), ACTION: With the requirements of the above specification not satisfied, remove power from the isolated loop isolation valve operators (1) within 1 hour. SUPJZILLANCE REQUIREMENTS 4.4.1.4.2 Verify at least once per 7 days that power is removed from the RCS isolated loop stop valve operators (l). (1) Power may be restored to the associated RCS isolated loop isolation valve operators provided the requirements of Surveillance Requirement 4.4.1.5.2 have been satisfied. (2) With fuel in the vessel. BEAVER VALLEY - UNIT 2 3/4 4-Sa Amendment No. (Proposed Wording)
NPF-73 REACTOR COOLANT SYSTEM 3.a.1.5 (Th4+-specification-number-4 Hot ~used. ) l L> I?e p /c. c e w I tA r m a u/- G 1 l l l l I BEAVER VALLEY - 8::it'. 2 3/4 4-6 ( Pre pcs ccciOeed;,,g
EA R COOLANT SYSTEM ISOLATED LOOP STARTUP LIMITING CONDITION FOR OPERATION 3.4.1.5 Each RCS isolated loop shall remain isolated with:
- a. The hot and cold leg isolation valve closed until the isolated portion of the loop has been drained and refilled from the Refueling Water Storage Tank or Reactor Coolant System, and
- b. The hot and cold leg isolation valves closed if the boron concentration in the isolated loop is less than the minimum required to satisfy the applicable requirements of Specification 3.1.1.2 for MODE 5 or Specification 3.9.1 for MODE 6.
APPLICABILITY: Whenever an RCS loop has been isolated greater than 4 hours or drained (l) . ACTION: With the requirements of the above specification not satisfied, immediately close the hot and cold leg isolation valves. SURVEILLANCE REQUIREMENTS l 4.4.1.5.1 Verify that the isolated loop has been drained and refilled with water from the Refueling Water Storage Tank or Reactor Coolant System prior to opening the hot or cold leg isolation valve in the isolated loop. 4.4.1.5.2 Verify that the isolated loop boron concentration is greater than or equal to the minimum required to satisfy the applicable requirements of Specification 3.1.1.2 for MODE 5 or Specification 3.9.1 for MODE 6 within 2 hours prior to opening the hot or cold leg isolation valve in the isolated loop. 4.4.1.5.3 Verify that the hot or cold leg isolation valve in the isolated loop is opened within 4 hours following completion of refilling the isolated loop. (1) With fuel in the vessel. BEAVER VALLEY - UNIT 2 3/4 4-6 Amendment No. (Proposed Wording)
NPF-73 3/4.9 REFUELING OPERATIONS BORON CONCENTRATION LIMITING CONDITION FOR OPERATION 3.9.1 With the reactor vessel head unbolted or removed, the boron concentration of all filled portions of the Reactor Coolant System and the refueling canal shall be maintained uniform and sufficient to ensure that the more restrictive of the following reactivity conditions is met: 3 1 I
- a. Either a K,ff of 0.95 or less, which includes a 1% ak/k conservative allowance for uncertainties, or
- b. A boron concentration of greater than or equal to 2000 ppm, which l includes a 50 ppa conservative allowance for uncertainties. i AAA4+4anm11u unlum grut.01 ekall ha einenA and emenenA 4a nne4+4an APPLICA8ILITY: MODE 6[ j ACTION:
-er- With the requirements of the above specification not satisfied, ,
immediately suspend all operations involving CORE ALTERATIONS or ! ! positive reactivity changes and initiate and continue boration at l
> 30 gpa of greater than or equal to 7000 ppe boric acid solution or ItsequivalentuntilK*N>isreducedto<0.95orthebaroncon-centration is restored 2000 ppe, whTchever is the more restric-i tive. l The provisions of Specification 3.0.3 are not applicable. l
- b- With ut!ve ?Cuc.91 mg 73 :3 eg erge 4.
pnjtten, 47:e3:::77 l
- !r e =d ::::= 8-
;nitir. {
i SURVEILLANCE RFOUIREMENTS ! i
- 4. 9.1.1 The more restrictive of the above two reactivity conditions shall be determined prior to:
l a. Removing or unbolting the reactor vessel head) and
- b. Withdrawal of any full length control rod in excess of 3 feet from !
its fully inserted position.
- 4. 9.1. 2 The boron concentration of the Reactor Coolant System and the i refueling canal shall be determined by chemical analysis at least 3 times per 7 days with (
a maximum time interval between samples of 72 hours. ;
' 9.1. 3 V:lv: 2C" M i :h:ll 5: v:ri'i:d :10::d =d teched tren '
pM'tir at
- 1:::t =:: p:r 31 d:y:.
(f)XThereactorshallbemaintainedinMODE6whenthereactorvesselheadis j unbolted or removed. BEAVER VALLEY - UNIT 2 3/4 9-1 (Pret-css wcvd
I I NPF-73 REACTIVfTY CONTROL SYSTEMS BASES 3/4.1.2 BORATION SYSTEMS (Continued) The boration capability required below 200*F is sufficient to provide a SHUTDOWN MARGI.N of 1% .1k/k after xenon decay and cooldown from 200 F to 140'F. This condition requires either 2315 gallons of 7000 ppm borated water from the boric acid storage tanks or 10,196 gallons of 2000 ppm' borated water frcm the refueling water storage tank. 3/4.1.3 MOVABLE CONTROL ASSEMBLIES i i The specifications of this section ensure that 1) acceptable power distri- I bution limits are maintained, 2) the minimus SHUTDOWN MARGIN is maintained, and 1
- 3) the potential effects of rod misalignment on associated accident analyses are limited. OPERABILITY of the movable control assemblies is established by observing rod motion and determining that rods are positioned within i 12 steps l (indicated position), of the respective group demand counter position. The l OPERABILITY of the control rod position indication system is required to deter- i mine control rod positions and thereby ensure compliance with the control rod !
alignment and insertion limits. ' The ACTION statements which permit limited variations from the basic re-quirements are accompanied by additional restrictions which ensure that the original design criteria are met. Misalignment of a rod requires measurement ) of peaking factors and a restriction in THERMAL POWER. These restrictions pro- ) vide assurance of fuel rod integrity during continued operation. In addition, those safety analyses affected by a misaligned rod are reevaluated to confirm that the results remain valid during future operation. Continuous monitoring of rod position with respect to insertion Ifmits and rod deviation is provided by the rod insertion limit monitor and rod deviation monitor, respectively. If the rod deviation monitor or the rod insertion limit monitor is inoperable, the frequency of manual comparison of indicated rod posi-tion is increased to an interval of at least once per 4 hours. The maximum rod drop time restriction is consistent with the assumed rod drop time used in the safety analyses. '9"*I to 541*F and with all reactor coolant Measurement with T,yg greater than or pumps operating ensures that the measured drop times will be representative of insertion times experienced dur-ing a reactor trip at operating conditions. For Specification 3.1.3.1 ACTIONS c. and d., it is. incumbent upon the plant to verify the trippability of the inoperable control rod (s). Trippability is defined in Attachment C to a letter dated December 21, 1984, from E. P. Rahe (Westinghouse) to C. O. Thomas (NRC). This may be by verification of a control system failure, usually electrical in nature, or that the failure is associated with the control rod stepping mechanism. In the event the plant is unable to verify the rod (s) trippability, it must be assumed to be untrippable and thus falls under the requirements of ACTION a. BEAVER VALLEY - UNIT 2 8 3/4 1-4 Amendment No.-it-(Pr o p eud % d , } )
! ll l Insert H < l Isolation of the primary grade water flow path during MODES 4, 5 and 6 precludes an unplanned boron dilution at these conditions since , the sole source of unborated water to the charging pumps is isolated. This eliminates the design basis boron dilution event in , MODES 4, 5 and 6. During planned boron dilution events, operator - attention will be focused on the boron dilution process and any inappropriate blender operation would be readily identified through various indications which includes the output from the source range nuclear instrumentation. 1 Closing either a) 2CHS-37 and 2CHS-828, or b) 2CHS-91, 2CHS-96, and 2CHS-138 will ensure that all possible flow paths are isolated from the Primary Grade Water System to the operating Reactor Coolant System flow path via the charging pumps, thus preventing any potential inadvertent boron dilution event by injection of unborated water. The ACTION to suspend all operations involving positive reactivity changes or CORE ALTERATIONS is intended to provide assurance that no other activity will mask any potential unintentional boron dilution event. Maintaining the Primary Grade Water System isolated is necessary to ensure that the design basis boron dilution event is not credible. Thus, immediate corrective action is needed to restore positive isolation as soon as possible when not conducting planned boron dilution or makeup activities. Lack of continuous corrective action to restore the Limiting Condition For Operation (LCO) would then make a potential inadvertent boron dilution credible and require performing additional analysis to verify acceptable consequences if it should occur. Verifying the SHUTDOWN MARGIN within one hour ensures that no unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. The SHUTDOWN MARGIN need only be verified once since the cessation of any activities involving positive reactivity changes, CORE ALTERATIONS or use of the Primary Grade Water System with the Charging System will prevent any future potential injection of Primary Grade Water into the Reactor Coolant System. The verification of SHUTDOWN MARGIN needs to be completed anytime that the ACTION is entered even if the LCO is subsequently ; satisfied before the verification is completed to ensure that no unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. i The primary function of the surveillance is to ensure that the valve (s) used to isolate the Primary Grade Water System are locked, sealed or otherwise secured. The frequency of 31 days to ensure that the Primary Grade Water System is properly isolated is based on engineering judgment, and has proven to be acceptable. Operating , experience has shown that the failure rate is so low that the 31 day frequency is justified. A time frame of 15 minutes provides a minimum reasonable time for an operator to isolate the Primary Grade Water System following a planned activity requiring its use. l
~
NPF-73 ' 3/4.4 REACTOR COOLANT SYSTEM BASES . 3/4.4.1.1,ppAkTOR COOLANT LOOPS AND COOLANT CIRCULATION The plant is designed to operate with all reactor coolant icops i: Operation and maintain DNBR above the design DNBR limit during all ncr a' operations and anticipated transients. In MODES 1 and 2, with :nc reactor coolant loop not in operation, this specification requires tna; the plant be in at least HOT STANDBY within 6 hours. l In MODE 3, a single reactor coolant loop provides sufficient heat removal capability for removing decay heat; however, due to the initia; conditions assumed in the analysis for the control rod bank withdrawal from a subcritical condition, two operating coolant loops are required :: meet the DNB design basis for this Condition II event when the rec control system is capable of control bank rod withdrawal. In MODES 4 and 5, a single reactor coolant loop or RHR subsyster provides single failure considerations require that at sufficient heat removal capability for removing decay heat; but OPERABLE. least two loops be Thus, if the reactor coolant loops are not OPERABLE, this specification requires two RHR loops to be OPERABLE. adequate The operation of one Reactor Coolant Pump or one RHR pump provides flow to ensure mixing, prevent stratification and produce gradualCoolant Reactor reactivity System. changes during boron concentration reductions in thel reduction will, The reactivity change rate associated with boron i therefore, be within the capability of operatorI recognition and control. The restrictions on starting a Reactor Coolant Pump with one or more RCS cold legs less than or equal to 350*F are provided to prevent RCS pressure transients, 1 caused by energy additions from the secondaryj system, which could exceed the limits of Appendix G to 10 CFR Part 50. t The RCS will be protected against overpressure transients and will not I exceed the limits of /$pendix G by restricting starting of the RCPs te when the secondary water temperature of each steam generator is less than 50*F above each of the RCS cold leg temperatures. k
- w. , .i.n r ., .c j
BEAVER VALLEY - UNIT 2 B 3/4.4-1 Amendment No. +6-( Prop o.ted Werd Q)
I Insert I Page 1 of 6 3/4.4.1.4 LOOP ISOLATION VALVES BACKGROUND The RCS may be operated with loops isolated in order to perform maintenance. While operating with a loop isolated, there is a potential for inadvertently opening the isolation valves in the isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. This situation has the potential for causing a positive reactivity addition with a corresponding reduction of SHUTDOWN MARGIN if the boron concentration in the isolated loop is less than the required SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriate sudden positive reactivity addition from unborated water because: a . LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating loops below the required SHUTDOWN MARGIN; and
- b. The loop isolation valves cannot be opened unless the loop has been drained and refilled with water supplied from the Refueling Water Storage Tank or from the Reactor Coolant System. This would include water from the refueling cavity.
This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless specifically intended by a procedure.
APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance with the NRC SER on N-1 loop operation. During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop isolation valve until the isolated loop is drained and refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System, and the isolated loop boron concentration is verified. Verification of the isolated loop boron concentration prior to opening the isolated - loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity effect from the isolated loop does not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design
Insert I Page 2 of 6 Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety analyses. LCO LCO 3.4.1.4.1 ensures that a loop isolation valve that becomes closed in MODES 1 through 4 is fully closed and the plant placed in MODE 5. LCO 3.4.1.4.2 ensures that power is removed from isolated loop isolation valve operators when closed to perform maintenance in MODES 5 or 6 to prevent an inadvertent loop startup. APPLICABILITY LCO 3.4.1.4.1 is applicable in MODES 1 through 4 and LCO 3.4.1.4.2 is applicable whenever an RCS loop has been isolated in MODES 5 and 6 with fuel in the reactor vessel. LCO 3.4.1.4.2 is not applicable when there is no fuel in the reactor vessel. In MODES 5 and 6, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS loop is considered isolated in MODES 5 and 6 whenever the hot , and cold leg isolation valves on one RCS loop are both in a fully i closed position at the same time. One isolation valve may be ; stroked for testing in MODES 5 and 6 and the loop will not be ' considered isolated when either the hot leg or cold leg loop l isolation valve remains open. ' ACTION For LCO 3.4.1.4.1
.a_ ,_ S h o u l d a l o o p i s o l a t i o n v a l v e b e c l o s e d i n M O D E S 1 through 4, )
the affected loop isolation valve (s) must be maintained 1 closed and the plant placed in MODE 5 to preclude inadvertent startup of the loop and the subsequent potential inadvertent positive reactivity insertion or criticality. The Completion Time of the ACTIONS allow time for borating the operating l loops to a shutdown boration level such that the plant can be brought to MODE 3 within 6 hours and MODE 5 within 36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without , challenging plant systems. l b If power is inadvertently restored to one or more loop i isolation valve operators, the potential exists for l accidental isolation of a loop with a subsequent inadvertent startup of the isolated loop. The loop isolation valves have motor operators. Therefore, these valves will maintain their l
Insert I Page 3 of 6 last position when power is removed from the valve operator. With power applied to the valve operators, only administrative controls prevent the valve from being [ operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to remove power from the loop isolation valve operators. The Comple. tion Time of 30 minutes to remove power from the loop isolation valve operators is sufficient considering the complexity of the task. For LCO 3.4.1.4.2 If power is inadvertently restored to one or more loop isolation valve operators, the potential exists for accidental isolation of a loop with a subsequent inadvertent startup of the isolated loop. The loop isolation valves have motor operators. Therefore, these valves will maintain their last position when power is removed from the valve operator. With power applied to the valve operators, orly administrative controls prevent the valve from being operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to remove power from the loop isolation valve operators. The completion Time of 1 hour to remove power from the loop isolation valve operators is sufficient considering the complexity of the task. SURVEILLANCE REOUIREMENTS (SR) SR 4.4.1.4.1 SR 4.4.1.4.1 is performed at least once per 31 days to ensure that the RCS loop isolation valves are open, with power removed from the loop isolation valve operators. The primary function of this surveillance is to ensure that power is removed from the valve operators, since SR 4.4.1.1 ensures that the loop isolation valves are open by verifying every 12 hours that all loops are operating and circulating reactor coolant. The frequency of 31 days ensures that the required flow can be made available, is based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 31 day frequency is justified. SR 4.4.1.4.2 SR 4.4.1.4.2 is performed at least once per 7 days to ensure that the RCS loop isolation valves have power removed from the loop isolation valve operators. The frequency of 7 days which ensures that the power is removed from loop isolation valve operators, is based on engineering judgment, and has proven to be acceptable. j Opercting experience has shown that the failure rate is so low that l the 7 day frequency is justified. l i 1 l l 1
Insert I Page 4 of 6 3/4.4.1.5 ISOLATED LOOP STARTUP BACKGROUND The RCS may be operated with loops isolated in order to perform maintenance. While operating with a loop isolated, there is a potential for inadvertently opening the isolation valves in the isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. This situation has the potential for causing a positive reactivity addition with a corresponding reduction of SHUTDOWN MARGIN if the boron concentration in the isolated loop is less than the required SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriate sudden positive reactivity addition from unborated water because: a . LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating loops below the required SHUTDOWN MARGIN; and
- b. The loop isolation valves cannot be opened unless the loop has been drained and refilled with water supplied from the Refueling Water Storage Tank or from the Reactor Coolant System. This would include water from the refueling cavity.
This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless specifically intended by a procedure.
APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance with the NRC SER on N-1 loop operation. During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop isolation valve until the isolated loop is drained and refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System, and the isolated loop boron concentration is verified. Verification of the isolated loop boron concentration prior to opening the isolated loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity effect from the isolated loop does not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design
Insert I Page 5 of 6 Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety analyses. LCQ Loop isolation valves are used for performing maintenance when the plant is in MODES 5 or 6. LCO 3.4.1.5 ensures that the loop i isolation valves remain closed on an isolated loop until the SHUTDOWN MARGIN in the isolated loop is within acceptable limits. l I, APPLICABILITY In MODES 5 and 6, the SHUTDOWN MARGIN of the operating loops is large enough to permit operation with isolated loops. In these MODES, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS loop is considered isolated in MODES 5 and 6 whenever the hot and cold leg isolation valves on one RCS loop are both in a fully closed position at the same time. One isolation valve may be stroked for testing in MODES 5 and 6 and the loop will not be considered isolated when either the hot leg or cold leg loop isolation valve remains open. ACTION The ACTION for LCO 3.4.1.5 assumes that the prerequisites of the LCO are not met and a loop isolation valve has been inadvertently opened. Therefore, the ACTION requires immediate closure of isolation valves to preclude a potential boron dilution event. SURVEILLANCE REOUIREMENTS ( SR_)_ SR 4.4.1.5.1 and 4.4.1.5.3 As an additional measure to ensure that the boron concentration in an isolated loop remains within acceptable limits, SR 4.4.1.5.1 requires that an isolated loop is drained and refilled with borated water supplied from the Refueling Water Storage Tank or Reactor Coolant System prior to-opening the hot or cold leg isolation valve in the isolated loop. The 4 hour time limit ensures that there is no unacceptable boron concentration stratification in an isolated loop. These surveillance frequencies have been shown to be acceptable through operating experience. l
Insert I Page 6 of 6 SR 4.4.1.5.2 To ensure that the boron concentration of the isolated loop meets acceptable limits, SR 4.4.1.5.2 is performed within 2 hours prior to j opening either the hot or cold leg isolation valve. This provides reasonable assurance that the boron concentration will stay within j acceptable limits until the loop is unisolated. ' l l l l I
ATTACHMENT B Beaver Valley Power Station, Unit Nos. 1 and 2 Proposed Technical Specification Change No. 224 AND 95 REVISION OF BORON DILUTION CRITERIA A. DESCRIPTION OF AMENDMENT REQUEST The proposed amendment would revise the boron dilution requirements to incorporate criteria similar to the boron dilution specifications currently required for the Surry, North Anna, and Millstone No. 3 units, and would incorporate the guidance provided in NUREG-1431, " Improved Standard Technical Specifications for Westinghouse Plants," with some modifications to address plant specific design features. This change incorporates two important features: (1) requires that an isolated Reactor Coolant System (RCS) loop be drained and filled with water from the Refueling Water Storage Tank (RWST) or RCS, eliminating the possibility of a boron dilution event when starting up an isolated loop, and (2) provides a positive means of isolating the primary grade water from the charging pumps in Modes 4, 5 and 6, eliminating the possibility of RCS boron dilution by injecting unborated water. This change also prohibits operation with less than all reactor coolant loop isolation valves open in Modes 1 through 4. B. BACKGROUND There are few Westinghouse-NSSS designed plants which contain RCS loop isolation valves. Units with loop isolation valves are provided with operational opportunities not afforded the Westinghouse-NSSS designed plants without them. The proposed , changes are requested to allow the Beaver Valley Power Station (BVPS) Units 1 and 2 Technical Specifications addressing boron dilution criteria to be similar to the boron dilution specifications at other Westinghouse-NSSS designed units with loop isolation valves. This will provide advantages when isolating the RCS loops for maintenance activities and during the return of an isolated RCS loop to service with fuel in the reactor, while retaining the necessary nuclear safety protection against a potential inadvertent boron dilution event. Incorporating the l same boron dilution protection criteria in Modes 4, 5 and 6 will allow consistent handling through operational procedures and provide other operational benefits. Due to the timing of receiving the operating licence for the two units, the previous , basis for each unit's technical specifications on boron dilution ! i is slightly different. This change request will make these bases for both units consistent. l C. JUSTIFICATION BVPS Unit 1 Proposed Chances Technical Specification (TS) 3.1.2.9 is being added to provide the requirement for lockout of the primary grade water flow path
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 l Page 2 during Modes 4, 5 and 6. A new technical specification is being created since no similar BVPS Unit 1 section contains this kind of requirements (and BVPS Unit 2 has the same numbered technical specification with similar criteria). The proposed technical specification is very similar to the current technical - specification for this same criteria at North Anna Power Station Units 1 and 2 (Amendment Numbers 3 and 120) and Surry Power Station Units 1 and 2 (Amendment Numbers 153 and 150). The principal means for a significant boron dilution is through the injection of unborated water into the RCS. Isolation of the primary grade water flow path during Modes 4, 5 and 6 precludes a significant unplanned boron dilution during these conditions since the sole source of unborated water (i.e., primary grade water) to the charging pumps is isolated and the low head safety injection pumps can not be aligned to the primary grade water supply. TS 3.3.3.1, Table 3.3-1, ACTION 5, is being modified to address locking the isolation valves on the primary grade water system. This ACTION is being modified to remain consistent with the same ACTION in the Unit 2 technical specifications. TS 3.4.1.1 is being revised to delete any reference to plant operation with less than all reactor coolant loops in Modes 1 and
- 2. The addition of the new proposed TS 3.4.1.4.1 prohibits this operation.
The previous BVPS Unit 1 TS 3.4.1.4 has been expanded into two separate technical specifications. The previous TS 3.4.1.4 has been renumbered to 3.4.1.4.2 with only editorial changes. A new technical specification is being proposed to be consistent with NUREG-1431, " Improved Standard Technical Specifications for Westinghouse Plants"(ISTS). This specification will ensure that power is removed from each loop isolation valve operator to prevent an inadvertent loop isolation during Modes 1 through 4. These are additional controls to ensure that no reactivity addition can occur to the core from a subsequent inadvertent opening of an isolated loop isolation valve following an inadvertent closing. This specification also prohibits operation with less than all reactor coolant loops in operation during Modes 1 through 4. TS 3.4.1.5 is being modified to follow the criteria provided by the current Millstone Unit No. 3 technical specifications on Isolated Loop Startup. This specification is also being modified to follow the guidance for isolated loop startup provided in the ISTS. Requiring an isolated RCS loop to be drained and refilled within 4 hours prior to opening both loop isolation valves ensures adequate boron concentration in the water used to fill the loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratifications. Incorporating a requirement to ensure that water to refill the loop is supplied from the RWST or RCS prevents an inadvertent boron dilution event due to inappropriate blending of primary grade (unborated) water and its injection into the RCS. B-2 t _
ATTACHMENT D, continued Proposed Technical Specification Change Nos. 224 and 95 Page 3 TS 3.4.1.5 would include water from the refueling cavity since this water was originally supplied from the RWST. The proposed amendment on isolated loop startup will allow the current interlock to be defeated which recirculates the isolated loop for 90 minutes before opening the cold leg loop isolation valve. The recirculation was originally conducted by operating the reactor coolant pump (RCP) in the isolated loop. Running an RCP causes two concerns: (1) With an RCP running in an isolated loop, there is no adequate method to control the heatup of that loop. The steam generator is less effective until the temperature exceeds 212 F and the Residual Heat Removal (RHR) system suction / discharge is on the reactor vessel side of the loop isolation valves. (2) Running the RCP in an isolated loop produces a very low flow compared to its normal operating flow rate. This condition is a reliability concern for the RCP and for increasing the potential for significant pump damage. This also increases the number of start /stop cycles on the RCP. During the first few fuel cycles of operation at BVPS Unit 1, the RCPs were used to meet the 90 minute recirculation criteria. Subsequently the method to recirculate an isolated loop was modified to use the charging pump. This arrangement has also resulted in several operational difficulties. By following the currently accepted approach used by Millstone Unit No. 3, the operational diff'.culties involved with recirculating an isolated loop describea above will be eliminated. The 90 minute recirculation interlock will be defeated and the proposed criteria to drain and refill within a four hour time period will be used in its place. The drain and refill of an isolated loop with water supplied from the RWST or RCS ensures that there will be no inadvertent reactivity transient when restoring an isolated loop. The incorporation of a time limit addresses any stratification concerns raised by the deletion of the recirculation requirements. This criteria is amplified by the proposed bases for this specification. The ISTS for RCS isolated loop startup contains a requirement in the Limiting Condition for Operation (LCO) to verify that the cold leg isolation valve remains closed if the temperature of the isolated loop is greater than [20 F] below the cold leg j temperature of the operating loop. The Bases section states that this requirement is to reduce the potential for causing a positive reactivity addition with a corresponding reduction of shutdown margin. The BVPS Unit 1 proposed technical specification on RCS isolated loop startup has removed this ISTS criteria on temperature mismatch. The LCO criteria proposed for shutdown margin minimum B-3
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 Page 4 requirements already takes into consideration operation of the complete reactor coolant system down to the minimum allowed temperature limit, which for both BVPS units is currently 68 F. Thus, any operation at or above this limit will not invalidate the calculated shutdown margin criteria. Startup of any isolated RCS loop with a wider temperature differential than 20 F would result in a lowering of the operating reactor coolant temperature and the actual shutdown margin. However, the resultant shutdown margin will still be above the required shutdown margin (specified in the LCO) if the operating RCS is maintained above 68 F since the shutdown margin calculations already address operating the whole RCS at the minimum allowed operating temperature. Current operating procedures based on TS 3.1.1.2 for Mode 5 or TS 3.9.1 for Mode 6 already require that shutdown margin calculations consider operating down to the minimum temperature of 68 F. Any drop in RCS temperature is acceptable with regard to shutdown margin while continuing to operate at or above the minimum temperature used to calculate the required shutdown margin. Few Westinghouse designed nuclear plants have RCS loop isolation valves. Research into the origins of this LCO requirement on RCS loop temperature differential limitation during loop startup specified in the ISTS indicates that this RCS loop temperature differential criteria stems from the early Westinghouse design feature for potential operation at power with one (or more) RCS loops isolated. The design was supposed to allow for recovering an isolated RCS loop at reduced power. Positive reactivity insertion due to even a relatively small temperature drop would be very important when assuming that the reactor could be critical to avoid potential rapid core reactivity changes or supercriticality. However, proposed TS 3.4.1.4.1 eliminates any critical operation without all RCS loop isolation valves open. Startup of an isolated loop with fuel in the reactor vessel is now limited to Modes 5 or 6, with the reactor suberitical (maintaining an adequate shutdown margin). Thus, the shutdown margin specified in TS 3.1.1.2 for Mode 5 or TS 3.9.1 for Mode 6 provides adequate margin and operating control for any positive reactivity which could be introduced through a temperature reduction from opening loop isolation valves. Thus, eliminating the potential for operating in Modes 1 through 4 with an RCS loop isolated also eliminates the basis and the need for maintaining a temperature differential limitation when opening loop isolation valves. Limitations of 10 CFR Appendix G will not be exceeded when loop isolation valves are opened even if the operating reactor coolant temperature is relatively high for Mode 5 and an isolated loop is filled with water at the minimum temperature specified for the RWST required by TS 3.1.2.7 (i.e., 4 5 F) , which is the lowest conceivable temperature for the RWST. The limiting Appendix G components are in the reactor vessel and not in the reactor coolant loops. Current TS 3.4.9.3 for BVPS Unit 1 would still apply requiring the Overpressure Protection System (OPPS) which uses power operated relief valves to be operable with nominal trip B-4
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 Page 5 setpoints set for Modes 5 or 6 conditions. The current setpoint of 432 psig is well below the pressure limitations shown in Figure B 3/4 4-3, isolated RCS loop pressure-temperature limit curve, shown in the BVPS Unit 1 technical specification Bases. This curve, developed by Westinghouse, provides the limitation on an isolated loop based on the most limiting material in the reactor coolant loop rather than in the reactor vessel. The allowed loop pressures for low temperatures are much higher than the current OPPS setpoint required by TS 3.4.9.3. Thus, the current OPPS used in Modes 5 and 6 (which limit the RCS to a maximum of 200 F) provides adequate overpressure protection for an RCS loop which may be unisolated at any conceivable temperature established by water supplied from the RWST. The minimum RCS temperature is 68 F which is higher than the minimum temperature for the RWST. BVPS Unit 2 Proposed Chances TS 3.1.2.9 is being modified for similar technical reasons as explained for BVPS Unit 1 and for consistency between both units. The changes to the BVPS Unit 2 TS 3.1.2.9 reflects the desire to maintain a consistent approach for boron dilution protection between both BVPS units in their procedures and requirements. The proposed Unit 2 TS 3.1.2.9 specifies the same boron dilution protection requirements for Modes 4, 5 and 6. This specification will replace the previous TS 3.1.2.9 criteria which was employed in Modes 4 & 5 and different criteria addressed in TS 3.9.1 for Mode 6. There are basically two options for dealing with a boron dilution event in Modes 4, 5 or 6. The first option, which was previously used by BVPS Unit 2 in Modes 4 and 5, is to provide analytical analyses to show that consequences of a worst case inadvertent boron dilution event can be mitigated within the time frames suggested by the Standard Review Plan for each mode. The previous TS 3.1.2.9 required that an orifice be placed into service limiting the maximum possible flow rate that the primary grade water header can supply to the charging pumps in Mode 5. The second option, which was used by BVPS Unit 2 in Mode 6, is to preclude the event by requiring that the source of primary grade water be locked, sealed or otherwise secured in the closed position except during planned dilution or makeup events. There are operational advantages and disadvantages associated with each option. Use of the lockout feature involves added personnel requirements to unlock and relock the valve during dilution and makeup activities. In addition, because radiation fields in the vicinity of the chemical and volume control system equipment can be significant, there are ALARA (as low as reasonably achievable) concerns. On the other hand, use of other administrative measures such as valving in a flow path that contains an orifice also ~ involves local manual actions and causes separate actions to address boron dilution protection in each mode. In addition, B-5
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 Page 6
)
boron dilution analyses could be adversely influenced by closure of the loop isolation valves which reduces the active RCS volume. It is being proposed that the lockout feature as currently specified at the Surry and North Anna plants and as currently specified during Mode 6 at BVPS Unit 2 also be used for Modes 4 ! and 5. The primary grade water flow path to the chemical and l volume control system (CVCS) is currently isolated during l refueling conditions (Mode 6). This precludes the possibility of an inadvertent boron dilution due to injection of unborated water at refueling conditions. It is proposed that the administrative isolation of the primary grade water flow path be made a technical specification requirement during Modes 4, 5 and 6. The i appropriate valves are specified in the specification to ensure i that the source of primary grade water is completely isolated from the charging pumps when not being used for planned makeup events. This precludes the design basis boron dilution event in Modes 4, 5 and 6. TS 3.3.3.1, Table 3.3-1, ACTION 5, is being modified to address a previous erroneous conclusion that locking only 2CHS-91 completely isolates the primary grade water supply to the CVCS. The error was discovered during the development of this technical specification change request. The revised TS 3.3.3.1 recognizes that additional valves need to be locked to completely isolate the primary grade water header supply. TS 3.4.1.4.1 and TS 3.4.1.4.2 are being added to ensure that no single failure could cause the startup of an isolated loop. These new technical specifications, consistent with the specifications proposed for BVPS Unit 1, would provide additional controls to ensure that no reactivity addition to the core can occur while an RCS loop is isolated due to inadvertent opening of the isolated loop stop valves. Restoration of power to the loop isolation valves ensures that loop isolation valve movement is conducted under controlled conditions. TS 3.4.1.5 is being modified for similar technical reasons as explained for BVPS Unit 1 and is being written similarly for consistency between both units. The RCS loop temperature differential limitation during isolated loop startup is also not included for BVPS Unit 2. The same technical basis applies to BVPS Unit 2 as described above for BVPS Unit 1. However, the BVPS Unit 2 TS 3.4.9.3 for the OPPS provides a modulated relief valve setpoint based on an auctioneered i resistance temperature detector (RTD) temperature, rather than a single setpoint valid for all temperatures as provided for BVPS Unit 1. The highest auctioneered pressure setpoint allowed by TS 3.4.9.3 is still below the maximum pressure allowed by Figure B 3/4 4-3 in the technical specification Bases for an isolated RCS loop at a minimum temperature (e.g., minimum conceivable temperature established by water supplied from the RWST, 4 5 F) . Thus, even though BVPS Unit 2 operates in Mode 5 and 6 with a B-6 a
I ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 l Page 7 l l variable OPPS setpoint, adequate overpressure protection is ( provided for any RCS loop which may have had its loop isolation l valves opened and was filled' with potentially cooler water from l the RWST. l TS 3.9.1 is being modified to delete Mode 6 boron dilution ; protection criteria. TS 3.1.2.9 now addresses boron dilution ! protection criteria for Modes 4, 5 and 6, negating the need for Mode 6 boron dilution criteria to remain in TS 3.9.1. 1 I D. SAFETY ANALYSIS BVPS Unit 1 Proposed Chances ! Uncontrolled boron dilution events are evaluated in Section 14.1.4 l in the BVPS Unit 1 Updated Final Safety Analysis Report (UFSAR). ; Dilution is described during refueling (Mode 6), startup (Mode 2) l and at power (Mode 1). The BVPS Unit 1 UFSAR does not currently i describe any boron dilution protection criteria during Modes 3, 4 , and 5. The analyses show that the amount of time available during refueling for the operator to determine the cause of the dilution, isolate the reactor water makeup source and initiate boration ; before the available shutdown margin is lost during the design basis event is 28 minutes. The proposed TS 3.1.2.9 would require that the primary grade water source to the RCS makeup system be [ locked, sealed or otherwise secured during Modes 4, 5 and 6. This ; will prevent the design basis boron dilution event and thus the + available shutdown margin will not be lost. This is the same l boron dilution prevention method currently approved for BVPS Unit [ 2 during Mode 6 and for the North Anna and Surry units in Mode 5. ! The proposed TS 3.1.2.9 will apply throughout Modes 4, 5 and 6. ! Power operation with less than all reactor coolant loops operating [ was not previously permitted. The changes to TS 3.4.1.1 and ! TS 3.4.1.4.1 reinforce this criteria. i Startup of an inactive reactor coolant loop is evaluated in Section 14.1.6 in the BVPS Unit 1 UFSAR. It describes startup of ! an isolated loop for two conditions: (1) with loop isolation { valves open, and (2) with loop isolation valves closed. The first : condition was originally written to address the possibility of l starting up an isolated loop when the reactor is critical. ! TS 3.4.1.1 currently prohibits operation in Mode 1 or 2 with a i loop isolated. This option is not being pursued and its description will be deleted from the UFSAR. The second condition ; is startup of an isolated loop with the isolation valves closed, j The UFSAR concludes that interlocks provided by the Reactor i Protection System insure that the temperature and boron l concentration in an isolated loop are brought to equilibrium with ; the remainder of the system at a slow rate. Should administrative 1 procedures be violated and an attempt to open isolation valves I when the isolated loop boron concentration is lower than that in ! the core, the reactivity addition rate is slow enough to allow the l B-7
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 l Page 8 ) cperator to take corrective action before shutdown margin is lost. [ Note the UFSAR does not define that rate or time.] UFSAR Section 14.1.6.1.2 describes three interlocks which: (1) Prevent opening of a hot leg isolation valve unless the cold leg isolation valve in the same loop is fully closed. ! (2) Prevent starting a reactor coolant pump unless a) the cold leg , I loop isolation valve in the same leg is fully closed, or b) l l both the hot leg and cold leg loop isolation valves are fully open. (3) Provent opening of a cold leg isolation valve unless a) the I hot leg loop isolation valve in the same loop has been fully opened for at least one hour, b) the bypass valve in the loop has been opened for at least one hour, c) flow has existed l through the relief line for at least one hour, and d) the hot and cold leg temperatures are within 20 F of the highest hot / cold leg temperature in the other loops. l The second interlock described above will not be modified. The l third interlock involving recirculating coolant in the isolated l loop will be defeated. With the third interlock defeated, the I need for the first interlock will be removed. In place of the interlock to recirculate, TS 3.4.1.5 will require that an isolated loop be drained and refilled from the RWST or RCS within 4 hours of returning an RCS loop to service. The RWST l contains adequate water to fill an isolated RCS loop. Borated water supplied from the RWST or RCS will prevent any inadvertent reactivity transients in lieu of the interlock which protected ) against a loop being filled with primary grade (unborated) water 1 through inadequate blender operation. Administrative controls will prevent any boron dilution of a filled isolated RCS loop before it is unisolated. Multiple human errors would have to occur for a potential inadvertent boron dilution in a filled isolated RCS loop. Thus a boron dilution event cannot occur when unisolating an RCS loop which reduces the shutdown margin below the limit required by TS 3.1.1.1 for Mode 4, TS 3.1.1.2 for Mode 5, or TS 3.9.1 for Mode 6. General Design Criteria (GDC) 10 l requirements are not exceeded with respect to demonstrating specified acceptable fuel design limits. Power is removed from RCS loop isolation valve operators when isolated to prevent inadvertent opening and any consequential adverse RCS or Residual Heat Removal System effects. BVPS Unit 2 Proposed Chances CVCS malfunctions that result in a decrease in the boron concentration in the reactor coolant are evaluated in Section 15.4.6 in the BVPS Unit 2 UFSAR. It identifies that the primary l means of causing an inadvertent boron dilution is the opening of the primary grade water makeup control valve and the failure of B-8 l l \
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 Page 9 the blend system, either by controller or mechanical failure. Boron dilution protection is described for each mode of operation. The proposed technical specification changes will not alter these descriptions for any mode except Modes 4, 5 and 6. Dilution during refueling (Mode 6) is currently prevented by administrative controls which isolate the RCS from the potential source of unborated water, the Primary Grade Water System (PGWS). UFSAR analysis for boron dilution events during hot and cold shutdown (Modes 4 & 5) previously required that administrative controls place an 85 gpm flow limiting device in the PGWS flow paths used to supply the CVCS in order to show that at least 15 minutes is available before the loss of shutdown margin. The proposed TS 3.1.2.9 will now require that administrative controls lock, seal or otherwise secure the PGWS source to the CVCS in order to prevent the design basis dilution event (except during planned boron dilution or makeup events) and hence the shutdown margin will not be lost. Thus, the boron dilution protection described for Mode 6 will also be applied to Modes 4 and 5. During planned boron dilution or makeup events, operator attention will be focused on the boron dilution process and any inappropriate blender operation will be readily identified. The use of the RWST as a source of makeup will also remain available. The proposed TS 3.4.1.4.1 and 3.4.1.4.2 provide additional administrative controls to ensure that no single failure could cause the startup of an isolated loop. These new technical specifications, consistent with TS 3.4.1.4 previously in place at BVPS Unit 1, would provide additional controls to ensure that no reactivity addition to the core can occur while an RCS loop is isolated due to inadvertent opening of the isolated loop isolation valves. Startup of an inactive reactor coolant loop is evaluated in Section 15.4.4 in the BVPS Unit 2 UFSAR. It provides a similar description as in the Unit 1 UFSAR about startup of an isolated l loop for two conditions: (1) with loop isolation valves open, and (2) with loop isolation valves closed. The first condition was originally written to address the possibility of starting an isolated loop when the reactor is critical. TS 3.4.1.1 currently prohibits operation in Mode 1 or 2 with a loop isolated. Similar to Unit 1, this option is not being pursued and its description will be deleted from the UFSAR. For the second condition with loop stop valves closed, the same technical basis applies for Unit 2 as previously described for Unit 1. Thus, a boron dilution event cannot occur which reduces the shutdown margin below the limit required by TS 3.1.1.1 for Mode 4, TS 3.1.1.2 for Mode 5, or TS 3.9.1 for Mode 6. GDC 10 requirements are not exceeded with respect to demonstrating specified acceptable fuel design limits. B-9
ATTACHMENT B, continued Proposed Technical Specification Change Nos. 224 and 95 Page 10 E. NO SIGNIFICANT HAZARDS EVALUATION The no significant hazard considerations involved with the proposed amendment have been evaluated, focusing on the three standards set forth in 10 CFR 50.92(c) as quoted below: The Commission may make a final determination, pursuant to the procedures in paragraph 50.91, that a proposed amendment to an operating license for a facility licensed under paragraph 50.21(b) or paragraph 50.22 or for a testing facility involves no significant hazards consideration, if operation of the facility in accordance with the proposed amendment would not: (1) Involve a significant increase in the probability or l consequences of an accident previously evaluated; or l (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety. The following evaluation is provided for the no significant l hazards consideration standards.
- 1. Does the change involve a significant increase in the probability or consequences of an accident previously evaluated?
The proposed amendment would modify the method used to prevent an inadvertent boron dilution event during hot shutdown, cold shutdown and during refueling. An uncontrolled boron dilution transient cannot occur during this mode of operation. Inadvertent boron dilution is prevented by administrative controls which isolate the primary grade water system isolation valves from the Chemical and Volume Control System, except during planned boron dilution or makeup activities. Thus unborated water can not be injected into the reactor coolant system, making an unplanned boron dilution at these conditions highly improbable, since the source of unborated water to the charging pumps is isolated. This precludes the primary means for an inadvertent boron dilution event in this mode of operation. The primary grade water system isolation valves may be opened , when directed by the control room during this mode of operation only for a planned boron dilution or makeup activity. The primary grade water system isolation valves will be verified to be locked, sealed or otherwise secured in the closed position after the planned boron dilution or makeup activity is completed. During planned boron dilution events, operator attention will be focused on the boron B-10
p ATTACHMENT B, continu::d Proposed Technical Specification Change Nos. 224 and 95 l Page 11 dilution process and any inappropriate blender operation will be readily identified. The operator has prompt and definite indication of any boron dilution from the audible count rate instrumentation supplied by the source range nuclear instrumentation. High count rate is alarmed in the reactor containment and the control room. In addition a high source range flux level is alarmed in the control room. The count rate increase is proportional to the subcritical multiplication factor. The proposed amendment would also modify the method used to prevent an adverse reactor transient during startup of an isolated reactor coolant loop. Procedures require that the isolated loop water boron concentration be verified prior to opening loop isolation valves. Procedures also require an isolated loop to be drained and refilled from water supplied from the Refueling Water Storage Tank (RWST) or Reactor Coolant System (RCS) prior to opening either the hot or cold leg isolation valves. Using water from the RWST or RCS ensures 1) that the boron concentration of the isolated loop is sufficient to prevent a dilution of the active reactor coolant loops and reducing the shutdown margin to below those values used in safety analyses when the isolated loop is returned to service, and 2) that no single failure could cause an isolated loop to be filled with unborated water. Thus procedures and interlocks prevent inadvertent opening of loop isolation valves and require that the startup of an isolated loop be performed in a controlled manner that virtually eliminates any sudden positive reactivity addition from boron dilution. Thus the core cannot be adversely affected by the startup of an isolated loop and fuel design limits are not exceeded. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?
The proposed changes do not create the possibility of a new or different kind of accident. No new systems, structures or components are being proposed. Acceptable alternative administrative controls are being proposed to address inadvertent boron dilution and the startup of inactive reactor coolant loops. The primary source of unborated water will be isolated from injecting by the charging pumps into the reactor coolant system during hot shutdown, cold shutdown and refueling, except for planned boron dilution events and makeup activities. The proposed administrative controls prevent the possible accident previously evaluated, i.e., an inadvertent boron dilution event. B-11
ATTACHMENT B, continued Propo:cd Technical Specification Change Nos. 224 and 95 I Page 12 A currently installed interlock to recirculate reactor coolant in an isolated loop is proposed to be deleted. In its place, each reactor coolant isolated loop will be drained and refilled with water supplied from the RWST just before i the loop is returned to service. This administrative control I will prevent any inadvertent reactivity transient when returning the loop to service. Thus, the proposed administrative controls will prevent the type of accident previously evaluated.
- 3. Does the change involve a significant reduction in a margin of safety?
The proposed changes will continue to ensure that adequate l protection is provided against an inadvertent boron dilution and the adverse effects from the startup of an isolated reactor coolant loop. General Design Criteria 10 requirements will not be exceeded with respect to demonstrating specified acceptable fuel design limits. The l required indications and functions are still maintained in l accordance with current technical specification requirements l and the shutdown margin is unaffected. Therefore, the l proposed change will not involve a significant reduction in the margin of safety. F. NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION Based on the considerations expressed above, it is concluded that the activities associated with this license amendment request satisfies the no significant hazards consideration standards of 10 CFR 50. 92 (c) and, accordingly, a no significant hazards consideration finding is justified. G. UFSAR CHANGES See Attachments D-1 and D-2. l B-12
ATTACHMENT C-1 Beaver Valley Power Station, Unit No. 1 Proposed Technical Specification Change No. 224 Applicable Typed Pages
F ATTACHMENT TO LICENSE AMENDMENT NO. FACILITY OPERATING LICENSE NO. DPR-66 : DOCKET NO. 50-334 Replace the following pages of Appendix A, Technical Specifications, with the enclosed pages as indicated. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change. Remove Insert Index Page IV Index Page IV Index Page VI Index Page VI 3/4 1-17a 3/4 3-6 3/4 3-6 3/4 4-1 3/4 4-1 3/4 4-2 ---- 3/4 4-2a ---- 3/4 4-3 3/4 4-3 3/4 4-3a 3/4 4-4 3/4 4-4 B 3/4 1-2a B 3/4 1-2a B 3/4 1-2b B 3/4 4-1 B 3/4 4-1 B 3/4 4-la B 3/4 4-la B 3/4 4-lb B 3/4 4-ic B 3/4 4-id B 3/4 4-le B 3/4 4-1f B 3/4 4-1g (Proposed Wording)
DPR-66 INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.0 APPLICABILITY..................................... 3/4 0-1 3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 BORATION CONTROL 3/4.1.1.1 Shutdown Margin - Tavg > 2 0 0 F . . . . . . . . . . . . . . . 3 / 4 1-1 3/4.1.1.2 Shutdown Margin - Tavg s 2 00 F . . . . . . . . . . . . . . . 3 / 4 1-3 3/4 1.1.3 Boron Dilution.............................. 3/4 1-4 3/4.1.1.4 Moderator Temperature Coefficient........... 3/4 1-5 3/4.1.1.5 Minimum Temperature for Criticality......... 3/4 1-6 3/4.1.2 BCRATION SYSTEMS 3/4.1.2.1 Flow Paths - Shutdown....................... 3/4 1-7 3/4.1.2.2 Flow Paths - Operating...................... 3/4 1-9 3/4.1.2.3 Charging Pump - Shutdown.................... 3/4 1-11 3/4.1.2.4 Charging Pumps - Operating.................. 3/4 1-12 3/4.1.2.5 Boric Acid Transfer Pumps - Shutdown........ 3/4 1-13 3/4.1.2.6 Boric Acid Transfer Pumps - Operating....... 3/4 1-14 3/4.1.2.7 Borated Water Sources - Shutdown............ 3/4 1-15 3/4.1.2.8 Borated Water Sources _ Operating . . . . . . . . . . . 3/4 1-16 3/4.1.2.9 Isolation of Unborated Water Sources Shutdown.................................. 3/4 1-17a 3/4.1.3 MOVABLE CONTROL ASSEMBLIES 3/4.1.3.1 Group Height................................ 3/4 1-18 3/4.1.3.2 Position Indication Systems - Operating..... 3/4 1-20 3/4.1.3.3 Position Indication System - Shutdown....... 3/4 1-21
,. 3/%.1.3.4 Rod Drop Time............................... 3/4 1-22 3/4.1.3.5 Shutdown Rod Insertion Limit................ 3/4 1-23 3/4.1.3.6 Control Rod Insertion Limits................ 3/4 1-23A BEAVER VALLEY - UNIT 1 IV Amendment No.
(Proposed Wording) s _ _ _ _ _ _ - - - - _ - - -
s DPR-66 XFDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS 3/4.4.1.1 Normal Operation............................ 3/4'4-1 l i 3/4.4.1.2 Hot Standby................................. 3/4 4-2b l 3/4.4.1.3 Shutdown.................................... 3/4 4-2c 3/4.4.1.4.1 Loop Isolation Valves -' Operating........... 3/4 4-3 ; l 3/4.4.1.4.2 Loop Isolation Valves - Shutdown............ 3/4 4-3a P 3/4.4.1.5 Isolated Loop Startup....................... 3/4 4-4 3/4.4.1.6 Reactor Coolant Pump Startup................ 3/4 4-4a ; 3/4.4.2 SAFETY VALVES - SHUTDOWN.................... 3/4 4-5 3/4.4.3 . SAFETY VALVES - OPERATING................... 3/4 4-6 ; 3/4.4.4 PRESSURIZER................................. 3/4 4-7 ; 3/4.4.5 3/4 4-8 STEAM GENERATORS............................ 1 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE 3/4.4.6.1 Leakage Detection Instrumentation........... 3/4 4-11 3/4.4.6.2 Operational Leakage......................... 3/4 4-13 3/4.4.6.3 Pressure Isolation Valves................... 3/4 4-14a 3/4.4.7 CH EM I STRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 / 4 4 - 15 3/4.4.8 SPECIFIC ACTIVITY........................... 3/4 4-18 3/4.4.9 PRESSURE / TEMPERATURE LIMITS 3/4.4.9.1 Reactor Coolant System...................... 3/4 4-22 l 1 BEAVER VALLEY - UNIT 1 VI Amendment No. (Proposed Wording)
DPR-66 ; REACTYVITY CONTROL SYSTEMS l ISOLATION OF UNBORATED WATER SOURCES - SHUTDOWN t LIMITING CONDITION FOR OPERATION ; L i 3.1.2.9 The following valves shall be locked, sealed or otherwise i secured in the closed position except during planned boron dilution ! or makeup activities- ! t
- a. 1CH-90, or ;
- b. 1CH-91 and 1CH-93 !
APPLICABILITY: MODES 4, 5 and 6. , ACTION: With the requirements of the above specification not satisfied, ! perform the following: ;
- 1. Immediately suspend all operations involving positive i reactivity changes, CORE ALTERATIONS or any use of the ,
Primary Grade Water System with the Charging System,
- 2. Immediately initiate actions to lock, seal or otherwise secure the required valve (s) in the closed position as soon i as possible, and j
- 3. Verify within 1 hour (1) that the SHUTDOWN MARGIN is greater l than or equal to the minimum required as per the applicable specification listed below and follow the applicable specification ACTIONS as necessary:
Specification Apolicable MODE 3.1.1.1 4 3.1.1.2 5 3.9.1 6 SURVEILLANCE REQUIREMENTS 4.1.2.9 The above listed valve (s) shall be verified to be locked, i sealed or otherwise secured in the closed position:
- a. Within 15 minutes after a planned boron dilution or makeup activity, and
- b. At least once per 31 days.
(1) This action is required to be completed regardless of when the requirements of the above specification are satisfied. l ) BEAVER VALLEY - UNIT 1 3/4 1-17a Amendment No. (Proposed Wording)
F DPR-66 TABLE 3.3-1 (Continued) ACTION 4 - With the number of channels OPERABLE one less than required by the Minimum Channels OPERABLE requirement and with the THERMAL POWER level:
- a. Below P-6, restore the inoperable channel to OPERABLE status prior to increasing THERMAL POWER above the P-6 setpoint.
- b. Above P-6, operation may continue.
ACTION 5 - With the number of OPERABLE channels one less than required by the Minimum Channels OPERABLE requirement, verify compliance with the SHUTDOWN MARGIN requirements of Specification 3.1.1.1 or Specification 3.1.1.2, as applicable within 1 hour, and at least , once per 12 hours thereafter, and verify valves (1CH-90) or (1CH-91 and 1CH-93) are closed and secured in position within the next hour. ACTION 6 - Not Applicable. ACTION 7 - With the number of OPERABLE channels (4)one less than the Total Number of Channels, STARTUP and/or POWER OPERATION may proceed provided the following conditions are satisfied:
- a. The inoperable channel is placed in the tripped condition within 6 hours, and
- b. The Minimum Channels OPERABLE requirement is met; however, the inoperable channel may be bypassed for up to 4 hours for surveillance testing of other channels per Specification 4.3.1.1.1.
ACTION 8 - With the number of OPERABLE channels one less than the Tot:u Number of Channels and with the THERMAL POWER level above P-7, place the inoperable channel in the tripped condition within 6 hours; operation may continue until performance of the next required CHANNEL FUNCTIONAL TEST. ACTION 9 - Not Applicable. l ACTION 10 - Not Applicable. 1 (4) An OPERABLE hot leg channel consists of: 1) three RTDs per hot leg, or 2) two RTDs per hot leg with the failed RTD disconnected and the required bias applied. BEAVER VALLEY - UNIT 1 3/4 3-6 Amendment No. (Proposed Wording)
r 1 DPR-66 I 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS l NORMAL OPERATION j l l LIMITING CONDITION FOR OPERATION . i i 3.4.1.1 All reactor coolant loops shall be in operation. l APPLICABILITY: MODES 1 and 2. l i ACTION: ; i With less than the above required reactor coolant loops in , operation, be in at least HOT STANDBY within 6 hours. ! SURVEILLANCE REQUIREMENTS ! t 4.4.1.1 All reactor coolant loops shall be verified in operation ! and circulating reactor coolant at least once per 12 hours. i i l i i i I BEAVER VALLEY - UNIT 1 3/4 4-1 Amendment No. (Next Page is 3/4 4-2b) l (Proposed Wording)
. _ . . . - . . - . .. . . _ . = , -
DPR-66 ; REACTOR COOLAMT SYSTEM l LOOP ISOLATION VALVES - OPERATING i LIMITING CONDITION FOR OPERATION 3.4.1.4.1 Each RCS hot and cold leg loop isolation valve shall be ! open with power removed from each isolation valve operator, t APPLICABILITY: MODES 1, 2, 3 and 4. i ACTION: ! I
- a. With one or more RCS loop isolation valve (s) closed, '
maintain the valve (s) closed, be in MODE 3 within the next 1 6 hours, and be in MODE 5 within the following 30 hours.
- b. With power available to one or more loop isolation valve i operators, remove power fr the loop isolation valve i operators within 30 minutes. (gm) !
SURVEILLANCE REQUIREMENTS l l 4.4.1.4.1 Verify at least once per 31 days that each RCS loop l isolation valve is open and power is removed from each isolation ! valve operator. ; I i (1) Separate Condition entry is allowed for each RCS loop isolation ! valve. l l BEAVER VALLEY - UNIT 1 3/4 4-3 Amendment No. (Proposed Wording)
DPR-66 REACTOR COOLANT SYSTEM LOOP ISOLATION VALVES - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.4.1.4.2 The loop isolation valves in an isolated RCS loop shall have power removed from the associated loop isolation valve operators (l). APPLICABILITY: Whenever an RCS loop has been isolated, MODES 5 and 6(2), ACTION: With the requirements of the above specification not satisfied, remove power from the isolated loop isolation valve operators (1) l within 1 hour. SURVEILLANCE REQUIREMENTS 4.4.1.4.2 Verify at least once per 7 days that pgwer from the RCS isolated loop isolation valve operators I. is removed l l [ (1) Power may be restored to the associated RCS isolated loop isolation valve operators provided the requirements of Surveillance Requirement 4.4.1.5.2 have been satisfied. l (2) With fuel in the vessel. l BEAVER VALLEY - UNIT 1 3/4 4-3a Amendment No. . (Proposed Wording) i j
DPR-66 REACTOR COOLANT SYSTEM ISOLATED LOOP STARTUP LIMITING CONDITION FOR OPERATION 3.4.1.5 Each RCS isolated loop shall remain isolated with:
- a. The hot and cold leg isolation valve closed until the isolated portion of the loop has been drained and refilled from the Refueling Water Storage Tank or Reactor Coolant '
System, and
- b. The hot and cold leg isolation valves closed if the boron concentration in the isolated loop is less than the minimum required to satisfy the applicable requirements of !
Specification 3.1.1.2 for MODE 5 or Specification 3.9.1 for MODE 6. i APPLICABILITY: Whenever an RCS loop has been isolated greater than 4 hours or drained (l). l l l ACTION: With the requirements of the above specification not satisfied, immediately close the hot and cold leg isolation valves. , I SURVEILLANCE REQUIREMENTS 4.4.1.5.1 Verify that the isolated loop has been drained and refilled with water from the Refueling Water Storage Tank or Reactor Coolant System prior to opening the hot or cold leg isolation valve in the isolated loop. 4.4.1.5.2 Verify that the isolated loop boron concentration is ] greater than or equal to the minimum required to satisfy the applicable requirements of Specification 3.1.1.2 for MODE 5 or Specification 3.9.1 for MODE 6 within 2 hours prior to opening the hot or cold leg isolation valve in the isolated loop. 4.4.1.5.3 Verify that the hot or cold leg isolation valve in the isolated loop is opened within 4 hours following completion of refilling the isolated loop. (1) With fuel in the vessel. BEAVER VALLEY - UNIT 1 3/4 4-4 Amendment No. (Proposed Wording)
DPR-66 , BE**TIVITY CONTROL SYSTEMS _ 1' BASES i 3/4.1.2 BORATION SYSTEMS (Continued) The required volume of water in the refueling water storage tank for reactivity considerations while operating is 424,000 gallons. The associated technical specification limit on the refueling water storage tank has been established at 441,100 gallons to account for reactivity considerations and the NPSH requirements of the ECCS system. The OPERABILITY of the RWST as part of the ECCS ensures that a sufficient supply of borated water is available for injection by the ECCS in the event of a LOCA. The limits on RWST minimum volume and boron concentration ensure that 1) sufficient water is available ! within containment to permit recirculation cooling flow to the core, and 2) the reactor will remain suberitical in the cold condition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the most reactive control assembly. These assumptions are consistent with the LOCA analysis. l The limitations for a maximum of one centrifugal charging pump to be OPERABLE and the Surveillance Requirement to verify all charging pumps except the required OPERABLE pump to be inoperable less than or equal to the enable temperature set forth in Specification 3.4.9.3 provides assurance that a mass addition pressure transient can be relieved by the operation of a single PORV. Substituting a Low Head Safety Injection pump for a charging pump in MODES 5 and 6 will not increase the probability of an overpressure event since the shutoff head of the Low Head Safety Injection pumps is less than or , equal to the setpoint of the overpressure protection system. Isolation of the primary grade water flow path during MODES 4, 5 and 6 precludes an unplanned boron dilution at these conditions since the sole source of unborated water to the charging pumps is isolated. This eliminates the design basis boron dilution event in J MODES 4, 5 and 6. During planned boron dilution events, operator attention will be focused on the boron dilution process and any inappropriate blender operation would be readily identified through , various indications which include the output from the source range nuclear instrumentation. l Closing either a) 1CH-90, or b) 1CH-91 and 1CH-93, will ensure that I all possible flow paths are isolated from the Primary Grade Water l System to the operating Reactor Coolant System flow path via the charging pumps, thus preventing any potential inadvertent boron dilution event by injection of unborated water. The . ACTION to suspend all operations involving positive reactivity changes or CORE ALTERATIONS is intended to provide assurance that no other activity will mask any potential unintentional boron dilution i BEAVER VALLEY - UNIT 1 B 3/4 1-2a Amendment No. (Proposed Wording) _ ____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ i
DPR-66 REACTIVITY CONTROL SYSTEMS I BASES 3/4.1.2 BORATION SYSTEMS (Continued _)_ event. Maintaining the Primary Grade Water System isolated is necessary to ensure that the design basis boron dilution event is not credible. Thus, immediate corrective action is needed to restore positive isolation as soon as possible when not conducting planned boron dilution or makeup activities. Lack of continuous corrective action to restore the Limiting condition For Operation (LCO) would then make a potential inadvertent boron dilution credible and require performing additional analysis to verify l acceptable consequences if it should occur. l Verifying the SHUTDOWN MARGIN within one hour ensures that no i unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. The SHUTDOWN MARGIN need only be verified once since the cessation of any activities involving positive reactivity changes, CORE ALTERATIONS or use of the Primary Grade Water System with the Charging System will prevent any future potential injection of Primary Grade Water into the Reactor Coolant System. The verification of SHUTDOWN MARGIN needs to be completed anytime that the ACTION is entered even if the LCO is subsequently satisfied before the verification is completed to ensure that no unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. The primary function of the surveillance is to ensure that the valve (s) used to isolate the Primary Grade Water System are locked, sealed or otherwise secured. The frequency of 31 days to ensure that the Primary Grade Water System is properly isolated is based on engineering judgment, and has proven to be acceptable. Operating . experience has shown that the failure rate is so low that the 31 day- ) frequency is justified. A time frame of 15 minutes provides a ! minimum reasonable time for an operator to isolate the Primary Grade ! Water System following a planned activity requiring its use. l BEAVER VALLEY - UNIT 1 B 3/4 1-2b Amendment No. (Proposed Wording)
? 1 DPR-66
))4.4 REACTOR COOLANT SYSTEM BASES i
3/4.4.1.1. 2. 3 REACTOR COOLANT LOOPS The plant is designed to operate with s.11 reactor coolant loops in operation and maintain DNBR above the design DNBR limit during all normal operations and anticipated transients. In Modes 1 and 2, with one reactor coolant loop not in operation, THERMAL POWER is restricted to less than or equal to 31 percent of RATED THERMAL POWER until the Overtemperature AT trip is reset. Either action ensures that the DNBR will be maintained above the design DNBR limit. A loss of flow in two loops will cause a reactor trip if operating above P-7 (11 percent of RATED THERMAL POWER) while a loss of flow in one loop will cause a reactor trip if operating above P-8 (31 percent of RATED THERMAL POWER). In MODE 3, a single reactor coolant loop provides sufficient heat removal capability for removing decay heat; however, due to the initial conditions assumed in the analysis for the control rod bank withdrawal from a subcritical condition, two operating coolant loops are required to meet the DNB design basis for this Condition II : event. In MODES 4 L'id 5, a single reactor coolant loop or RHR subsystem provides set f..cient heat removal capability for removing decay heat; but single taf*.ure considerations require that at least two loops be OPERABLE. Thus, if the reactor coolant loops are not OPERABLE, this specification requires two RHR loops to be OPERABLE. The operation of one Reactor Coolant Pump or one RHR pump provides : adequate flow to ensure mixing, prevent stratification and produce gradual reactivity changes during boron concentration reductions in the Reactor Coolant System. The reactivity change rate associated with boron reduction will, therefore, be within the capability of operator recognition and control. , I The restrictions on starting a Reactor Coolant Pump with one or more ; RCS cold legs less than or equal to 275F are provided to prevent ; RCS pressure transients, caused by energy additions from the secondary system, which could exceed the limits of Appendix G to ] 10 CFR Part 50. The RCS will be protected against overpressure i transients and will not exceed the limits of Appendix G by either i (1) restricting the water level in the pressurizer and thereby providing a volume for the primary coolant to expand into or (2) by restricting starting of the RCPs to when the secondary water temperature of each steam generator is less than 25 F above each of the RCS cold leg temperatures. l BEAVER VALLEY - UNIT 1 B 3/4 4-1 Amendment No. (Proposed Wording) I
)
DPR-66 3/4.4 REACTOR COOLANT SYSTEM BASES ) l 3/4.4.1.4 LOOP ISOLATION VALVES- I l BACKGROUND The RCS may be operated with loops isolated in order to perform maintenance. While operating with a loop isolated, there is a , potential for inadvertently opening the isolation valves in the - isolated loop. In this event, the coolant in the isolated loop ' would suddenly begin to mix with the coolant in the operating loops. This situation has the potential'for causing a positive reactivity addition with a corresponding reduction of SHUTDOWN MARGIN if the boron concentration in the isolated loop is less than the required l SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any l inappropriate sudden positive reactivity addition from unborated , water because:
- a. LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN l requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop !
that could dilute the boron concentration in the operating - loops below the required SHUTDOWN MARGIN; and j
- b. The loop isolation valves cannot be opened unless the loop has been drained and refilled with water supplied from the Refueling Water Storage Tank or from the Reactor Coolant System. This would include water.from the refueling cavity.
This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in < the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless j specifically intended by a procedure.
APPLICABLE SAFETY ANALYSES l Isolated loop startup is limited to MODES 5 and 6 in accordance with the NRC SER on N-1 loop operation. , l During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop isolation valve until the isolated loop is drained and refilled with water supplied BEAVER VALLEY - UNIT 1 B 3/4 4-la Amendment No. (Proposed Wording)
DPR-66 2/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) APPLICABLE SAFETY ANALYSES (Continued) from the Refueling Water Storage Tank or Reactor Coolant System, and the isolated loop boron concentration is verified. Verification of the isolated loop boron concentration prior to opening the isolated loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity effect from the isolated loop does not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety analyses. LCO LCO 3.4.1.4.1 ensures that a loop isolation valve that becomes closed in MODES 1 through 4 is fully closed and the plant placed in MODE 5. LCO 3.4.1.4.2 ensures that power is removed from isolated loop isolation valve operators when closed to perform maintenance in MODES 5 or 6 to prevent an inadvertent loop startup. APPLICABILITY LCO 3.4.1.4.1 is applicable in MODES 1 through 4 and LCO 3.4.1.4.2 is applicable whenever an RCS loop has been isolated in MODES 5 and 6 with fuel in the reactor vessel. LCO 3.4.1.4.2 is not applicable when there is no fuel in the reactor vessel. In MODES 5 and 6, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS loop is considered isolated in MODES 5 and 6 whenever the hot and cold leg isolation valves on one RCS loop are both in a fully closed position at the same time. One isolation valve may be stroked for testing in MODES 5 and 6 and the loop will not be considered isolated when either the hot leg or cold leg loop isolation valve remains open. BEAVER VALLEY - UNIT 1 B 3/4 4-lb Amendment No. (Proposed Wording)
DPR-66 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) ACTION l For LCO 3.4.1.4.1 ;
- g. Should a loop isolation valve be closed in MODES 1 through 4, the affected loop isolation valve (s) must be maintained closed and the plant placed in MODE 5 to preclude inadvertent startup of the loop and the subsequent potential inadvertent positive reactivity insertion or criticality. The Completion Time of the ACTIONS allow time for borating the operating loops to a shutdown boration j level such that the plant can be brought to MODE 3 within 6 hours and MODE 5 within 36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power .
conditions in an orderly manner and without challenging I plant systems.
- b. If power is inadvertently restored to one or more loop isolation valve operators, the potential exists for accidental isolation of a loop with a subsequent inadvertent startup of the isolated loop. The loop isolation valves have motor operators. Therefore, these valves will maintain their last position when power is removed from the valve operator. With power applied to the valve operators, only administrative controls prevent the valve from being operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to remove power from the loop isolation valve operators. The completion Time of 30 minutes to remove power from the loop isolation valve operators is sufficient considering the complexity of the task.
For LCO 3.4.1.4.2 If power is inadvertently restored to one or more loop isolation valve operators, the potential exists for accidental isolation of a l loop with a subsequent inadvertent startup of the isolated loop. The loop isolation valves have motor operators. Therefore, these valves will maintain their last position when power is removed from the valve operator. With power applied to the valve operators, only administrative controls prevent the valve from being operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to remove power from the loop isolation valve operators. The Completion Time of 1 hour to remove power from the loop isolation valve operators is sufficient considering the complexity of the task. BEAVER VALLEY - UNIT 1 B 3/4 4-ic Amendment No. (Proposed Wording)
_~ . . . - , - . . _ . . - - - - _ _ _ - . . - , i i DPR-66 3/4.4 REACTOR COOLANT SYSTEM , e i BASES 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) SURVEILLANCE REOUIREMENTS (SR) l SR 4.4.1.4.1 SR 4.4.1.4.1 is performed at least once per 31 days to ensure that i the RCS loop isolation valves are open, with power removed from the loop isolation valve operators. The primary function of this surveillance is to ensure that power is removed from the valve ! operators, since SR 4.4.1.1 ensures that the loop isolation valves , are open by verifying every 12 hours that all loops are operating and circulating reactor coolant. The frequency of 31 days ensures ; that the required flow can be made available, is based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 31 day frequency is justified. ; SR 4.4.1.4 2 ; SR 4.4.1.4.2 is performed at least once per 7 days to ensure that t the RCS loop isolation valves have power removed from the loop isolation valve operators. The frequency of 7 days which ensures , that the power is removed from loop isolation valve operators, is based on engineering judgment, and has proven to be acceptable. l Operating experience has shown that the failure rate is so low that : the 7 day frequency is justified. 3/4.4.1.5 ISOLATED LOOP STARTUP ; BACKGROUND l The RCS may be operated with loops isolated in order to perform i maintenance. While operating with a loop isolated, there is a i potential for inadvertently opening the isolation valves in the isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. This situation has the potential for causing a positive reactivity 1 addition with a corresponding reduction of SHUTDOWN MARGIN if the ! boron concentration in the isolated loop is less than the required l SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriate sudden positive reactivity addition from unborated water because:
- a. LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN BEAVER VALLEY - UNIT 1 B 3/4 4-1d Amendment No.
(Proposed Wording)
DPR-66 3/4.4 REACTOR COOLANT SYSTEM i BASES t 3/4.4.1.5 ISOLATED LOOP STARTUP (Continued) 4 BACKGROUND (Continued) requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating , loops below the required SHUTDOWN MARGIN; and ; i
- b. The loop isolation valves cannot be opened unless the loop ,
has been drained and refilled with water supplied from the ! Refueling Water Storage Tank or from the Reactor Coolant System. This would include water from the refueling cavity. . This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and -
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless specifically intended by a procedure.
i APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance with , the NRC SER on N-1 loop operation. During startup of an isolated loop in accordance with LCO .3.4.1.5, operating procedures prevent the opening of the loop isolation valve , until the isolated loop is drained and refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System, and . the isolated loop boron concentration is verified. Verification of l the isolated loop boron concentration prior to opening the isolated ' loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity : effect from the isolated loop does not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design i Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety 2 analyses. :
^
LCO t Loop isolation valves are used for performing maintenance when the plant is in MODES 5 or 6. LCO 3.4.1.5 ensures that the loop . isolation valves remain closed on an isolated loop until the ! SHUTDOWN MARGIN in the isolated loop is within acceptable limits. BEAVER VALLEY - UNIT 1 B 3/4 4-le Amendment No. (Proposed Wording)
l' DPR-66 3/4.4 REACTOR COOLANT SYSTEM BASES J/4.4.1.5 ISOLATED LOOP STARTUP (Continued) j APPLICABILITY l i In MODES 5 and 6, the SHUTDOWN MARGIN of the operating loops is large enough to permit operation with isolated loops. In these ! MODES, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS' loop is considered isolated in MODES 5 and 6 whenever the hot and cold leg isolation valves on one RCS loop are both in a fully ; closed position at the same time. One isolation valve may be . stroked for testing in MODES 5 and 6 and the loop will not be considered isolated when either the hot leg or cold leg loop isolation valve remains open. ACTION , The ACTION for LCO 3.4.1.5 assumes that the prerequisites of the LCO i are not met and a loop isolation valve has been inadvertently opened. Therefore, the ACTION requires immediate closure of isolation valves to preclude a potential boron dilution event. l SURVEILLANCE REOUIREMENTS (SR) SR 4.4.1.5.1 and 4.4.1.5.3 ; As an additional measure to ensure that the boron concentration in ; an isolated loop remains within acceptable limits, SR 4.4.1.5.1 ! requires that an isolated loop is drained and refilled with borated water supplied from the Refueling Water Storage Tank or Reactor : Coolant System prior to opening the hot or cold leg isolation valve l in the isolated loop. The 4 hour time limit ensures that there is , no unacceptable boron concentration stratification in an isolated j loop. These surveillance frequencies have been shown to be j acceptable through operating experience. ' SR 4.4.1.5.2 To ensure that the boron concentration of the isolated loop meets acceptable limits, SR 4.4.1.5.2 is performed within 2 hours prior to opening either the hot or cold leg isolation valve. This provides reasonable assurance that the boron concentration will stay within acceptable limits until the loop is unicolated. BEAVER VALLEY - UNIT 1 B 3/4 4-1f Amendment No, j (Proposed Wording)
DPR-66 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.2 and 3/4.4.3 SAFETY VALVES The pressurizer code safety valves operate to prevent the RCS from being pressurized above its Safety Limit of 2735 psig. Each safety valve is designed to relieve 345,000 lbs. per hour of saturated steam at the valve setpoint. The relief capacity of a single safety valve is adequate to relieve any overpressure condition which could occur during shutdown. In the event that no safety valves are OPERABLE, an operating RHR loop, connected to the RCS, provides overpressure relief capability and will prevent RCS overpressurization. During operation, all pressurizer code safety valves must be OPERABLE to prevent the RCS from being pressurized above its safety limit of 2735 psig. The combined relief capacity of all of these valves is greater than the maximum surge rate resulting from a I complete loss of load assuming no reactor trip until the first ) Reactor Protective System trip setpoint is reached (i.e., no credit i is taken for a direct reactor trip on the loss of load) and also assuming no operation of the power operated relief valves or steam dump valves. I I BEAVER VALLEY - UNIT 1 B 3/4 4-1g Amendment No. (Proposed Wording)
ATTACHMENT C-2 Beaver Valley Power Station, Unit No. 2 Proposed Technical Specification Change No. 95 Applicable Typed Pages i l 1 I I
l l 1 1 ATTACHMENT TO LICENSE AMENDMENT NO. FACILITY OPERATING LICENSE NO. NPF-73 DOCKET NO. 50-412 Replace the following pages of Appendix A, Technical Specifications, with the enclosed pages as indicated. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change. Remove Insert Index Page V Index Page V 3/4 1-17 3/4 1-17 l 3/4 3-6 3/4 3-6 3/4 4-1 3/4 4-1 3/4 4-5 3/4 4-5 3/4 4-Sa 3/4 4-6 3/4 4-6 3/4 9-1 3/4 9-1 B 3/4 1-4 B 3/4 1-4 B 3/4 1-5 B 3/4 1-6 B 3/4 4-1 B 3/4 4-1 - B 3/4 4-la B 3/4 4-lb B 3/4 4-ic B 3/4 4-1d B 3/4 4-le l B 3/4 4-1f l l l l 1 1
)
(Proposed Wording)
o NPF-73 ; INDEX l LIMITING CONDITION FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.2.4 QUADRANT POWER TILT RATIO ....................... 3/4 2-11 ; 3/4.2.5 DNB PARAMETERS .................................. 3/4 2-13 f 3/4.3 INSTRUMENTATION i 3/4.3.1 . REACTOR TRIP SYSTEM INSTRUMENTATION ............. 3/4 3-1 3/4.3.2 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM ...... 3/4 3-14 f INSTRUMENTATION 3/4.3.3 MONITORING INSTRUMENTATION Radiation Monitoring ............................ 3/4 3-39 , Movable Incore Detectors ........................ 3/4 3-45 , Seismic Instrumentation ......................... 3/4 3-46 ; Meteorological Instrumentation .................. 3/4 3-49 j Remote Shutdown Instrumentation ................. 3/4 3-52 , i Chlorine Detection Systems ...................... 3/4 3-56 , i Accident Monitoring Instrumentation ............. 3/4 3-57 j Radioactive Liquid Effluent Monitoring .......... 3/4 3-60 l Instrumentation Radioactive Gaseous Effluent Monitoring ......... 3/4 3-65 Instrumentation i t 3/4.3.4 TURBINE OVERSPEED PROTECTION .................... 3/4 3-74 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION Normal Operation ................................ 3/4 4-1 Hot Standby ..................................... 3/4 4-2 j Shutdown ........................................ 3/4 4-3 Loop Isolation Valves - Operating ............... 3/4 4-5 Loop Isolation Valves - Shutdown ................ 3/4 4-Sa Isolated Loop Startup ........................... 3/4 4-6 Reactor Coolant Pump-Startup .................... 3/4 4-7 3/4.4.2 SAFETY VALVES - SHUTDOWN ........................ 3/4 4-8
'3/4.4.3 SAFETY VALVES - OPERATING ....................... 3/4 4-9 3/4.4.4 PRESSURIZER ..................................... 3/4 4-10 1 i
3/4.4.5 STEAM GENERATORS ................................ 3/4 4-11 i BEAVER VALLEY - UNIT 2 V Amendment No. 1 (Proposed Wording) I 1
MPF-73 , REACTIVXTY CONTROL SYSTEMS ISOLATION OF UNBORATED WATER SOURCES - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.9 The following valves shall be locked, sealed or otherwise f secured in the closed position except during planned boron dilution L or makeup activities: i
- a. 2CHS-37 and 2CHS-828, or 1
- b. 2CHS-91, 2CHS-96 and 2CHS-138 APPLICABILITY: MODES 4, 5 and 6.
f ACTION: , With the requirements of the above specification not satisfied, perform the following:
- 1. Immediately suspend all operations involving positive reactivity changes, CORE ALTERATIONS or any use of the Primary Grade Water System with the Charging System,
- 2. Immediately initiate actions to lock, seal or otherwise secure the required valve (s) in the closed position as soon as possible, and
- 3. Verify within 1 hour ID that the SHUTDOWN MARGIN is greater ,
than or equal to the minimum required as per the applicable specification listed below and follow the applicable i specification ACTIONS as necessary: Specification boolicable MODE l 3.1.1.1 4 3.1.1.2 5 ) 3.9.1 6 ) l SURVEILLANCE REQUIREMENTS 4.1.2.9 The above listed valve (s) shall be verified to be locked, sealed or otherwise secured in the closed position:
- a. Within 15 minutes after a planned boron dilution or makeup activity, and
- b. At least once per 31 days.
(1) This action is required to be completed regardless of when the j
~
requirements of the above specification are satisfied. BEAVER VALLEY - UNIT 2 3/4 1-17 Amendment No. (Proposed Wording)
1 j NPF-73 TABLE 3.3-1 (Continued) ACTION 4 - With the number of channels OPERABLE one less than required by the Minimum Channels OPERABLE requirement and with the THERMAL POWER level:
- a. Below P-6, restore the inoperable channel to OPERABLE i
status prior to increasing THERMAL POWER above the P-6 setpoint and suspend positive reactivity operations.
- b. Above P-6, operation may continue.
ACTION 5 - With the number of OPERABLE channels one less than the Minimum Channels OPERABLE requirement, restore the inoperable channel to OPERABLE status within 48 hours or open the Reactor Trip System breakers, suspend all operations involving positive reactivity changes and verify valves (2CHS-91, 2CHS-96 and 2CHS-138) or (2CHS-37 and 2CHS-828) are closed and secured in position within the next hour. i ACTION 6 - This Action is not used. ACTION 7 - With the number of OPERABLE channels (4)one less than the Total Number of Channels, STARTUP and/or POWER OPERATION may proceed provided the following conditions are satisfied: , a . The inoperable channel is placed in the tripped condition within 6 hours, and
- b. The Minimum Channels OPERABLE requirement is met; however, the inoperable channel may be bypassed for up i to 4 hours for surveillance testing of other channels 1 per Specification 4.3.1.1.1.
ACTION 8 - With the number of OPERABLE channels one less than the Total Number of Channels and with the THERMAL POWER level above P-9, place the inoperable channel in the tripped condition within 6 hours; operation may continue until performance of the next required ! CHANNEL FUNCTIONAL TEST. ACTION 9 - This Action is not used. ACTION 10 - This Action is not used. (4) An OPERABLE hot leg channel consists of: 1) three RTDs per hot leg, or 2) two RTDs per hot leg with the failed RTD disconnected and the required bias applied. BEAVER VALLEY - UNIT 2 3/4 3-6 Amendment No. (Proposed Wording)
NPF-73 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION N_ORMAL OPERATION LIMITING CONDITION FOR OPERATION 3.4.1.1 All reactor coolant loops shall be in operation. APPLICABILITY: MODES 1 and 2. ACTION: With less than the above required reactor coolant loops in operation, be in at least HOT STANDBY within 6 hours. SURVEILLANCE REQUIREMENTS 4.4.1.1 All reactor coolant loops shall be verified in operation and circulating reactor coolant at least once per 12 hours. BEAVER VALLEY - UNIT 2 3/4 4-1 Amendment No. (Proposed Wording)
NPF-73 REACTOR COOLANT SYSTEM LOOP ISOLATION VALVES - OPERATING LIMITING CONDITION FOR OPERATION 3.4.1.4.1 Each RCS hot and cold leg loop isolation valve shall be , open with power removed from each isolation valve operator. I l APPLICABILITY: MODES 1, 2, 3 and 4. ; ACTION:
- a. With one or more RCS loop isolation valve (s) closed, maintain the valve (s) closed, be in MODE 3 within the next )
6 hours, and be in MODE 5 within the following 30 hours.
- b. With power available to one or more loop isolation valve operators, remove power fgm the loop isolation valve operators within 30 minutes l
SURVEILLANCE REQUIREMENTS 4.4.1.4.1 Verify at least once per 31 days that each RCS loop isolation valve is open and power is removed from each isolation valve operator. (1) Separate Condition entry is allowed for each RCS loop isolation valve. BEAVER VALLEY - UNIT 2 3/4 4-5 Amendment No. (Proposed Wording)
NPF-73 1 REACTOR COOLANT SYSTEM LOOP ISOLATION VALVES - SHUTDOWN l LIMITING' CONDITION FOR OPERATION ' 3.4.1.4.2 The loop isolation valves in an isolated RCS loop shall ! have powe removed from the associated loop isolation valve ! operators ([) 6 APPLICABILITY: Whenever an RCS loop has been isolated, MODES 5 and 6(2), ACTION: ; With the requirements of the above specification not satisfied, l remove power from the isolated loop isolation valve operators (l) ! within 1 hour. i l SURVEILLANCE REQUIREMENTS ! i 4.4.1.4.2 Verify at least once per 7 days that power is removed from the RCS isolated loop stop valve operators (1). l l i (1) Power may be restored to the associated RCS isolated loop isolation valve operators provided the requirements of Surveillance Requirement 4.4.1.5.2 have been satisfied. (2) With fuel in the vessel. ! i I 1 BEAVER VALLEY - UNIT 2 3/4 4-Sa Amendment No. (Proposed Wording)
NPF-73 REACTOR-COOLANT SYSTEM i ISOLATED LOOP STARTUP i i LIMITING CONDITION FOR OPERATION 3.4.1.5 Each RCS isolated loop shall remain isolated with: I
- a. The hot and cold leg isolation valve closed until the i isolated portion of the loop has been drained and refilled i from the Refueling Water Storage Tank or Reactor Coolant l System, and ,
i
- b. The hot and cold leg isolation valves closed if the boron :
concentration in the isolated loop is less than the minimum i required to satisfy the applicable requirements of ! Specification 3.1.1.2 for MODE 5 or Specification 3.9.1 for j MODE 6. : i APPLICABILITY: Whenever an RCS loop has been isolated greater than 4 hours or drained (l) .- ! ACTION: I With the requirements of the above specification not satisfied, I immediately close the hot and cold leg isolation valves. l t SURVEILLANCE REQUIREMENTS 4.4.1.5.1 Verify that the isolated loop has been drained and refilled with water from the Refueling Water Storage Tank or Reactor l Coolant System prior to opening the hot or cold leg isolation valve i in the isolated loop. j i 4.4.1.5.2 Verify that the isolated loop boron concentration is j greater than or equal to the minimum required to satisfy the ' applicable requirements of Specification 3.1.1.2 for MODE 5 or ! Specification 3.9.1 for MODE 6 within 2 hours prior to opening the l hot or cold leg isolation valve in the isolated loop. i 4.4.1.5.3 Verify that the hot or cold leg isolation valve in the ! isolated loop is opened within 4 hours following completion of refilling the isolated loop. l I (1) With fuel in the vessel. ) l BEAVER VALLEY - UNIT 2 3/4 4-6 Amendment No. (Proposed Wording)
1 NPF-73 ))4.9 REFUELING OPERATIONS BORON CONCENTRATION i LIMITING CONDITION FOR OPERATION l 3.9.1 With the reactor vessel head unbolted or removed, the boron concentration of all filled portions of the Reactor Coolant System and the refueling canal shall be maintained uniform and sufficient to ensure that the more restrictive of the following reactivity conditions is met:
- a. Either a Keff of 0.95 or less, which includes a 1% Ak/k conservative allowance for uncertainties, or
- b. A boron concentration of greater than or equal to 2000 ppm, which includes a 50 ppm conservative allowance for uncertainties.
l APPLICABILITY: MODE 6(1) . l ACTION: With the requirements of the above specification not satisfied, l immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes and initiate and continue boration at 2 30 gpm of greater than or equal to 7000 ppm boric acid solution or its equivalent until Keff is reduced to 5 0.95 or the boron concentration is restored to 2 2000 ppm, whichever is the more restrictive. The provisions of Specification 3.0.3 are not applicable. l SURVEILLANCE REQUIREMENTS 4.9.1.1 The more restrictive of the above two reactivity conditions shall be determined prior to:
- a. Removing or unbolting the reactor vessel head, and
- b. Withdrawal of any full length control rod in excess of 3 feet from its fully inserted position.
4.9.1.2 The boron concentration of the Reactor Coolant System and the refueling canal shall be determined by chemical analysis at least 3 times per 7 days with a maximum time interval between samples of 72 hours. I (1) The reactor shall be maintained in MODE 6 when the reactor l ; vessel head is unbolted or removed. BEAVER VALLEY - UNIT 2 3/4 9-1 Amendment No. (Proposed Wording) l
NPF-73 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.2 BORATION SYSTEMS (Continued) The boration capability required below 200 F is sufficient to provide a SHUTDOWN MARGIN of 1%dk/k after xenon decay and cooldown from 200 F to 140 F. This condition requires either 2315 gallons of 7000 ppm borated water from the boric acid storage tanks or 10,196 gallons of 2000 ppm borated water from the refueling water storage tank. Isolation of the primary grade water flow path during MODES 4, 5 and 6 precludes an unplanned boron dilution at these conditions since the sole source of unborated water to the charging pumps is isolated. This eliminates the design basis boron dilution event in MODES 4, 5 and 6. During planned boron dilution events, operator attention will be focused on the boron dilution process and any inapproprlate blender operation would be readily identifled through various indications which include the output from the source range nuclear instrumentation. Closing either a) 2CHS-37 and 2CHS-828, or b) 2CHS-91, 2CHS-96, and 2CHS-138, will ensure that all possible flow paths are isolated from the Primary Grade Water System to the operating Reactor Coolant System flow path via the charging pumps, thus preventing any potential inadvertent boron dilution event by injection of unborated water. The ACTION to suspend all operations involving positive reactivity changes or CORE ALTERATIONS is intended to provide assurance that no other activity will mask any potential unintentional boron dilution event. Maintaining the Primary Grade Water System isolated is necessary to ensure that the design basis boron dilution event is not credible. Thus, immediate corrective action is needed to restore positive isolation as soon as possible when not conducting planned boron dilution or makeup activities. Lack of continuous corrective action to restore the Limiting Condition For Operation (LCO) would then make a potential inadvertent boron dilution credible and require performing additional analysis to verify acceptable consequences if it should occur. Verifying the SHUTDOWN MARGIN within one hour ensures that no unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO requirements were not satisfied. The SHUTDOWN MARGIN need only be verified once since the cessation of any activities involving positive reactivity changes, CORE ALTERATIONS or use of the Primary Grade Water System with the Charging System will prevent any future potential injection of Primary Grade Water into the Reactor Coolant System. The verification of SHUTDOWN MARGIN needs to be completed anytime that the ACTION is entered even if the LCO is subsequently BEAVER VALLEY - UNIT 2 B 3/4 1-4 Amendment No. (Proposed Wording)
NPF-73 REACTIVITY CONTROL SYSTEMS ! BASES 3/4.1.2 BORATION SYSTEMS (Continued) satisfied before the verification is completed to ensure that no i unacceptable reduction of SHUTDOWN MARGIN occurred when the LCO i requirements were not satisfied. l The primary function of the surveillance is to ensure that the ! valve (s) used to isolate the Primary Grade Water System are locked, ! sealed or otherwise secured. The frequency of 31 days to ensure [ that the Primary Grade Water System is properly isolated is based on ' engineering judgment, and has proven to be acceptable. Operating l experience has shown that the failure rate is so low that the 31 day ! frequency is justified. A time frame of 15 minutes provides a i minimum reasonable time for an operator to isolate the Primary Grade ! Water System following a planned activity requiring its use. i i 3/4.1.3 MOVABLE CONTROL ASSEMBLIES l The specifications of this section ensure that 1) acceptable i power distribution limits are maintained, 2) the minimum SHUTDOWN MARGIN is maintained, and 2) the potential effects of rod l misalignment on associated accident analyses are limited. OPERABILITY of the movable control assemblies is established by , observing rod motion and determining that rods are positioned within l 1 12 steps (indicated position), of the respective group demand ! counter position. The OPERABILITY of the control rod position indication system is required to determine control rod positions and l thereby ensure compliance with the control rod alignment and insertion limits. The ACTION statements which permit limited variations from the basic requirements are accompanied by additional restrictions which ensure that the original design criteria are met. Misalignment of a rod requires measurement of peaking factors and a restriction in THERMAL POWER. These restrictions provide assurance of fuel rod integrity during continued operation. In addition, those safety analyses affected by a misaligned rod are reevaluated to confirm that the results remain valid during future operation. Continuous monitoring of rod position with respect to insertion limits and rod deviation is provided by the rod insertion limit monitor and rod deviation monitor, respectively. If the rod , deviation monitor or the rod insertion limit monitor is inoperable, the frequency of manual comparison of indicated rod position is l increased to an interval of at least once per 4 hours. The maximum rod drop time restriction is consistent with the assumed rod drop time used in the safety analyses. Measurement with T avg greater than or equal to 541 F and with all reactor coolant BEAVER VALLEY - UNIT 2 B 3/4 1-5 Amendment No. f (Proposed Wording)
s NPF-73
)
REACTIVITY CONTROL SYSTEMS BASES 3/4.1.3 MOVABLE CONTROL ASSEMBLIES (Continued) pumps operating ensures that the measured drop times will be representative of insertion times experienced during a reactor trip at operating conditions. For Specification 3.1.3.1 ACTIONS c. and d., it is incumbent ' upon the plant to verify the trippability of the inoperable control ' rod (s). Trippability is defined in Attachment C to a letter dated December 21, 1984, from E. P. Rahe (Westinghouse) to C. O. Thomas (NRC). This may be by verification of a control system failure, usually electrical in nature, or that the failure is associated with the control rod stepping mechanism. In the event the plant is unable to verify the rod (s) trippability, it must be assumed to be untrippable and thus falls under the requirements of ACTION a. l l l l I l l BEAVER VALLEY - UNIT 2 B 3/4 1-6 Amendment No. l (Proposed Wording)
NPF-73 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.1, 2, 3 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION l The plant is designed to operate with all reactor coolant loops in operation and maintain DNBR above the design DNBR limit during all normal operations and anticipated transients. In MODES 1 and 2, ! with one reactor coolant loop not in operation, this specification l requires that the plant be in at least HOT STANDBY within 6 hours. l In MODE 3, a single reactor coolant loop provides sufficient ! heat removal capability for removing decay heat; however, due to the ! initial conditions assumed in the analysis for the control rod bank ! withdrawal from a suberitical condition, two operating coolant loops ! are required to meet the DNB design basis for this Condition II j event when the rod control system is capable of control bank rod ; withdrawal. In MODES 4 and 5, a single reactor coolant loop or RHR subsystem ! provides sufficient heat removal capability for removing decay heat; ; but single failure considerations require that at least two loops be j OPERABLE. Thus, if the reactor coolant loops are not OPERABLE, this specification requires two RHR loops to be OPERABLE. i The operation of one Reactor Coolant Pump or one RHR pump provides adequate flow to ensure mixing, prevent stratification and ! produce gradual reactivity changes during boron concentration reductions in the - Reactor Coolant System. The reactivity change ! rate associated with boron reduction will, therefore, be within the ! capability of operator recognition and control. ; The restrictions on starting a Reactor Coolant Pump with one or [ more RCS cold legs less than or equal to 350 F are provided to [ prevent RCS pressure transients, caused by energy additions from the i secondary system, which could exceed the limits of Appendix G to 10 i CFR Part 50. The RCS will be protected against overpressure transients and will not exceed the limits of Appendix G by l restricting starting of the RCPs to when the secondary water temperature of each steam generator is less than 50 F above each of ! the RCS cold leg temperatures. ! 3/4.4.1.4 LOOP ISOLATION VALVES [ BACKGROUND I The RCS may be operated with loops isolated in order to perform i maintenance. While operating with a loop isolated, there is a ! potential for inadvertently opening the isolation valves in the ! isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. l I i BEAVER VALLEY - UNIT 2 B 3/4 4-1 Amendment No. 3 (Proposed Wording) I o
NPF-73 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) BACKGROUND (Continued) This situation has the potential for causing a positive reactivity addition with a corresponding reduction of SHUTDOWN MARGIN if the boron concentration in the isolated loop is less than the required SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriate sudden positive reactivity addition from unborated water because:
- a. LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the bcron concentration in the isolated loop be maintained higher than-the SHUTDOWN MARGIN requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating loops below the required SHUTDOWN MARGIN; and
- b. The loop isolation valves cannot be opened unless the loop has been drained and refilled with water supplied from the Refueling Water Storage Tank or from the Reactor Coolant System. This would include water from the refueling cavity.
This ensures adequate boron concentration in the water to refill the isolated loop, adequate mixing of the coolant in the isolated loop, and prevents any reactivity effects due to boron concentration stratification; and
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless l specifically intended by a procedure.
1 APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance with the NRC SER on N-1 loop operation. During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop isolation valve until the isolated loop is drained and refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System, and the isolated loop boron concentration is verified. Verification of the isolated loop boron concentration prior to opening the isolated loop isolation valves provides a reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures that any undesirable reactivity effect from the isolated loop does BEAVER VALLEY - UNIT 2 B 3/4 4-la Amendment No. (Proposed Wording) '
NPF-73 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) APPLICABLE SAFETY ANALYSES (Continued) not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as an initial condition for Design Basis Accidents (DBAs). Violation of the LCO, combined with mixing of the isolated loop coolant into the operating loops, could result in the SHUTDOWN MARGIN being less than that assumed in the safety analyses. L92 LCO 3.4.1.4.1 ensures that a loop isolation valve that becomes closed in MODES 1 through 4 is fully closed and the plant placed in MODE 5. LCO 3.4.1.4.2 ensures that power is removed from isolated loop isolation valve operators when closed to perform maintenance in MODES 5 or 6 to prevent an inadvertent loop startup. APPLICABILITY LCO 3.4.1.4.1 is applicable in MODES 1 through 4 and LCO 3.4.1.4.2 is applicable whenever an RCS loop has been isolated in i MODES 5 and 6 with fuel in the reactor vessel. LCO 3.4.1.4.2 is not applicable when there is no fuel in the reactor vessel. In MODES 5 i and 6, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. ! L An RCS loop is considered isolated in MODES 5 and 6 whenever the ! hot and cold leg isolation valves on one RCS loop are both in a ! fully closed position at the same time. One isolation valve may be , stroked for testing in MODES 5 and 6 and the loop will not be l considered isolated when either the hot leg or cold leg loop j isolation valve remains open. ! ACTION ! For LCO 3.4.1.4.1
- a. Should a loop isolation valve be closed in MODES 1 through 4, the af fected loop ! solation valve (s) must be maintained closed and the plant placed in MODE 5 to preclude inadvertent startup of the loop and the subsequent potential inadvertent positive reactivity insertion or criticality. The Completion Time of the ACTIONS allow time BEAVER VALLEY - UNIT 2 B 3/4 4-lb Amendment No.
(Proposed Wording)
i J NPF-73 I REACTOR COOLANT SYSTEM ! 3/404 l l BASES l 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) ! ACTION (Continued) h for ' borating the operating loops to a shutdown boration l level such that the plant can be brought to MODE 3 within l 6 hours and. MODE 5 within 36 hours. The allowed l Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. ,
- h. If Power is inadvertently restored to one or more loop {
isolation valve operators, the potential exists for i accidental isolation of a loop with a subsequent j inadvertent startup of the isolated loop. The loop i isolation valves have motor operators. Therefore, these ! valves will maintain their last position when power is ! removed from the valve operator. With power applied to the ! valve operators, only administrative controls prevent the valve from being operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to remove power from the loop isolation valve operators. The Completion Time of 30 minutes to remove power from the loop isolation valve operators is sufficient considering the complexity of the task. For LCO 3.4.1.4.2 f If power is inadvertently restored to oaa or more loop isolation i valve operators, the potential exists for accidental isolation ; of a loop with a subsequent inadvertent startup of the isolated i loop. The loop isolation valves have motor operators. . Therefore, these valves will maintain their last position when ! power is removed from the valve operator. With power applied to the valve operators, only administrative controls prevent the valve from being operated. Although operating procedures make the occurrence of this event unlikely, the prudent action is to , remove power from the loop isolation valve operators. The i Completion Time of 1 hour to remove power from the loop valve operators sufficient considering the l isolation is ; complexity of the task. : SURVEILLANCE REOUIREMENTS (SR) f SR 4.4.1.4.1 SR 4.4.1.4.1 is performed at least once per 31 days to ensure that ! the RCS loop isolation valves are open, with power removed from the J BEAVER VALLEY - UNIT 2 B 3/4 4-1c Amendment No. (Proposed Wording) ! l _ _ - .- - - .- _ _ - . ~ - __ __ - _ .._ __
NPF-73 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.4 LOOP ISOLATION VALVES (Continued) SURVEILLANCE REOUIREMENTS (SR) (Continued) : loop isolation valve operators. The primary function of this surveillance is to ensure that power is removed from the valve operators, since SR 4.4.1.1 ensures that the loop isolation valves are open by verifying every 12 hours that all loops are operating and circulating reactor coolant. The frequency of 31 days ensures that the required flow can be made available, is based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 31 day frequency is justified. SR 4.4.1.4.2 SR 4.4.1.4.2 is performed at least once per 7 days to ensure that the RCS loop isolation valves have power removed from the loop isolation valve operators. The frequency of 7 days which ensures that the power is removed from loop isolation valve operators, is based on engineering judgment, and has proven to be acceptable. Operating experience has shown that the failure rate is so low that the 7 day frequency is justified. 3/4.4.1.5 ISOLATED LOOP STARTUP BACKGROUND The RCS may be operated with loops isolated in order to perform maintenance. While operating with a loop isolated, there is a potential for inadvertently opening the isolation valves in the isolated loop. In this event, the coolant in the isolated loop would suddenly begin to mix with the coolant in the operating loops. This situation has the potential for causing a positive reactivity ! addition with a corresponding reduction of SHUTDOWN MARGIN if the l boron concentration in the isolated loop is less than the required i SHUTDOWN MARGIN. As discussed in the UFSAR, the startup of an isolated loop is performed in a controlled manner that virtually eliminates any inappropriate sudden positive reactivity addition from unborated water because:
- a. LCO 3.4.1.5, " Isolated Loop Startup," and plant operating procedures require that the boron concentration in the isolated loop be maintained higher than the SHUTDOWN MARGIN requirement for the operating loops, thus eliminating the potential for introducing coolant from the isolated loop that could dilute the boron concentration in the operating loops below the required SHUTDOWN MARGIN; and BEAVER VALLEY - UNIT 2 B 3/4 4-id Amendment No.
(Proposed Wording)
. . .- . - = _ - _ - NPF-73 3/4.4 REACTOR COOLANT SYSTEM i BASES 3/4.4.1.5 ISOLATED LOOP STARTUP (Continued) f 1 BACKGROUND (Continued) , i
- b. The loop isolation valves cannot be opened unless the loop j has been drained and refilled with water supplied from the ;
Refueling Water Storage Tank or from the Reactor Coolant ! System. This would include water from the refueling cavity. l This ensures adequate boron concentration in the water to i refill the isolated loop, adequate mixing of the coolant in j the isolated loop, and prevents any reactivity effects due + to boron concentration stratification; and i
- c. Removing the power from the loop isolation valve operator ensures that a loop isolation valve will not be moved unless !
specifically intended by a procedure. l APPLICABLE SAFETY ANALYSES Isolated loop startup is limited to MODES 5 and 6 in accordance j with the NRC SER on N-1 loop operation. , During startup of an isolated loop in accordance with LCO 3.4.1.5, operating procedures prevent the opening of the loop ; isolation valve until the isolated loop is drained and refilled with ; water supplied from the Refueling Water Storage Tank or Reactor ' Coolant System, and the isolated loop boron concentration is j verified. Verification of the isolated loop boron concentration i prior to opening the isolated loop isolation valves provides a : reassurance of the adequacy of the SHUTDOWN MARGIN. This ensures ! that any undesirable reactivity effect from the isolated loop does i not occur. The safety analyses assume a minimum SHUTDOWN MARGIN as l an initial condition for Design Basis Accidents (DBAs). Violation ' of the LCO, combined with mixing of the isolated loop coolant into j the operating loops, could result in the SHUTDOWN MARGIN being less i than that assumed in the safety analyses. (
}
LCO ! Loop isolation valves are used for performing maintenance when : the plant is in MODES 5 or 6. LCO 3.4.1.5 ensures that the loop i isolation valves remain closed on an isolated loop until the ! SHUTDOWN MARGIN in the isolated loop is within acceptable limits, i BEAVER VALLEY - UNIT 2 B 3/4 4-le Amendment No. (Proposed Wording)
NPF-73 3/4.4 REACTOR COOLANT SYSTEM BASES 3/4.4.1.5 ISOLATED LOOP STARTUP (Continued) APPLICABILITY In MODES 5 and 6, the SHUTDOWN MARGIN of the operating loops is large enough to permit operation with isolated loops. In these MODES, controlled startup of isolated loops is possible without significant risk of inadvertent criticality. An RCS loop _is considered isolated in MODES 5 and 6 whenever the hot and cold leg isolation valves on one RCS loop are both in a fully closed position at the same time. One isolation valve may be stroked for testing in MODES 5 and 6 and the loop will not be considered isolated when either the hot leg or cold leg loop isolation valve remains open. ACTION The ACTION for LCO 3.4.1.5 assumes that the prerequisites of the LCO are not met and a loop isolation valve has been inadvertently opened. Therefore, the ACTION requires immediate closure of isolation valves to preclude a potential boron dilution event. SURVEILLANCE REOUIREMENTS (SR) SR 4.4.1.5.1 and 4.4.1.5.3 As an additional measure to ensure that the boron concentration in an isolated loop remains within acceptable limits, SR 4.4.1.5.1 requires that an isolated loop is drained and refilled with borated water supplied from the Refueling Water Storage Tank or Reactor Coolant System prior to opening the hot or cold leg isolation valve in the isolated loop. The 4 hour time limit ensures that there is no unacceptable boron concentration stratification in an isolated loop. These surveillance frequencies have been shown to be acceptable through operating experience. SR 4.4.1.5.2 To ensure that the boron concentration of the isolated loop meets acceptable limits, SR 4.4.1.5.2 is performed within 2 hours prior to opening either the hot or cold leg isolation valve. This provides reasonable assurance that the boron concentration will stay within acceptable limits until the loop is unisolated. BEAVER VALLEY - UNIT 2 B 3/4 4-1f Amendment No. (Proposed Wording) l
ATTACHMENT D-1 Beaver Valley Power Station, Unit No. 1 Proposed Technical Specification Change No. 224 Applicable UFSAR Changes l l I l i l l
BVPS-1-UPDATED FSAR Rev. 10 (1/92) capacity of the primary water supply pumps. The maximum addition rate in this case is 300 gpm with both primary water supply pumps running. The 300 gpm reactor makeup water delivery rate is based on a pressure drop calculation comparing the pump curves with the system resistance curve. This is the maximum delivery based on the unit piping layout. Normally, only one charging pump is operating. The boric acid from the boric acid tank is blended with primary grade water in the blender and the composition is determined by the preset flow rates of boric acid and primary grade water on the control board. In order to dilute, two separate operations are required:
- 1. The operator must switch from the automatic makeup mode to the dilute mode
- 2. The makeup switch must be placed to START.
omitting either step would prevent dilution. Information on the status of the reactor coolant makeup is continuously available to the operator. Lights are provided on the control board to indicate the operating condition of the pumps in the Chemical and Volume Control System. Alarms are actuated to warn the operator if boric acid or demineralized water flow rates deviate from preset values as a result of system malfunction. 14.1.4.2 Method of Analysis and Results Boron dilution during refueling, startup, and power operation are considered in this analysis. Table 14.1-2 contains the time sequence of events for this accident. p sbaam,Gia sL uun .*J Dilution Durina.Refuelina i~ During refueling the follering conditiene exist-
- 1. One recidual heat rc=0 val pun; i Operating te encure-continuou: mixing ir the rc ctor v00:01.
- 2. The :::1 injection v ter cupply te the reacter ceclant-punp: in iceleted. ,
- 2. The v:1ve en the cuctier tide of the ch:rging purpc are l adjusted for addition of cencentrated beric acid
,m,,+4mm
--.----n-
- 4. Thc bcron concentration in the refueling v:ter in eppecxi= tely 2,000 ppm, with all red clucter centrol acec=blice in; periodic :=pling ensurc; that this concentratier it maintained.
l l l 14.1-12 ! he etcsd W c'd G)
i BVPS-1-UPDATED FSAR Ecv. 10 '1/93)
- 5. Neutren ccurccc Orc inctalled in the cerc and the ccurce rang = d=tec*^re outride the reacter veccel cre-astrive--and provide er audibic count rate. During initial core 10: ding EF2 dete-*^-~ '-- --'^' i- 4"
-the reacter veccel and are cer Octed tc inctrumentation giving andible coun* rates to provide direct menitcring cf the ,
nmen l uedi--p --- - A rinimu= '?ater volume ir the "cceter Ceci nt Systa; cf 2,005 : ft 3 is considered. Thic correcpend tc the vclume necccsary te fill the reacter vcacci abcvc the nc;;1cs to ensure mixing via the ; v_ o_ e _4 a_ n_ _o _, wm__+_
._._m_,,,,.__
___y.
.m. ... .emm .4. ... ... - 2. .:,..
.... u :- .<.,-. m1
. suu yem, ,
limited by the capacity Of the tue primary water makeup pumps, and uniform miving ic accumed. off g pc g 8pg. The operator has prompt and definite indication f any boron dilution from the audible count rate instrumentation g High count rate is alarmed in the reactor containment and the control room. In addition a high source range flux level is alarmed in the control room. The count rate increase is proportional to the suberitical multiplication factor.
-The arount cf time available for the cperater te determine the ' -cause of dilution, ieclate the reacter uater ==kenp ecurna =nA in4*4=*= har=*ian before the available chutdeu margir in lect ic 22 =inutcc.
Dilution Durina Startuo In the Startup Mode, the plant is being taken from one long term mode of operation, Hot Standby, to another, Power. Typically, the plant is maintained in the Startup Mode only for the purpose of startup testing at the beginning of each cycle. During this mode ; of operation rod control is in manual. All normal actions required to change power level, either up or down, require operator initiation. Conditions assumed for the analysis are:
- 1. A maximum dilution flow of 231 gpm.
- 2. A minimum RCS water volume of 7817 cubic feet. This active volume includes the reactor vessel volume, reactor coolant loop piping volumes and the primary steam generator volume.
Specifically excluded are the pressurizer and pressurizer surge line volumes.
- 3. The initial boron concentration is assumed to be 1800 ppm, which is a conservative maximum value for the critical concentration at the condition of hot zero power, rods to the insertion limits and no Xenon.
- 4. The critical boron concentration following reactor trip is assumed to be 1500 ppm, corresponding to the hot zero power, all rods inserted (minus the most reactive RCCA), no Xenon condition. The 300 ppm change from the initial condition 14.1-13 (Picpcw w r Nrp )
BVPS-1 UFSAR Insert No. 1 An uncontrolled boron dilution transient cannot occur during this mode of operation. The primary means for a significant boron dilution is through the injection of unborated water into the Reactor Coolant System. Inadvertent boron dilution is prevented by administrative controls which isolate the primary grade water system isolation valves from the Chemical and Volume Control System, except during planned boron dilution or makeup activities. Thus unborated water can not be injected into the Reactor Coolant System, making an unplanned boron dilution at these conditions highly improbable, since the source of unborated water to the charging pumps is isolated and the low head safety injection pumps can not be aligned to the primary grade water supply. This precludes the primary means for an inadvertent boron dilution event in this mode of operation. The primary grade water system isolation valves may be opened when directed by the control room during this mode of operation only for a planned boron dilution or makeup activity. The primary grade water system isolation valves will be verified to be locked, sealed or otherwise secured in the closed position within 15 minutes after the planned boron dilution or makeup activity is completed. During planned boron dilution events, operator attention will be focused on the boron dilution process and any inappropriate blender operation is unlikely and will be readily identified. l l (Proposed Wording) l I
BVPS-1-UPDATED FSAR Rev. 10 (1/02) the amount of time available for the operator to determine the cause of the dilution, isolate the reactor water makeup source, and initiate boration before the available shutdown margin is lost. With the reactor in manual control and no operator action taken to terminate the transient, the power and temperature rise will cause the reactor to reach the Overtemperature Delta-T trip setpoint resulting in a reactor trip. The boron dilution transient in this case is essentially the equivalent to an uncontrolled RCCA bank withdrawal at power. The maximum reactivity insertion rate for a boron dilution is conservatively estimated to be 2.5 pcm/sec, which is within the range of insertion rates analyzed. Thus, the effects of dilution prior to reactor trip are bounded by the Uncontrolled RCCA Bank Withdrawal at Power analysis (FSAR Section 14.1.2). Following reactor trip there are at least 16 minutes prior to criticality. the operator to determine the cause of the dilution, isolate the This is the amount of time available for reactor water makeup source, and initiate boration before the available shutdown margin is lost. # 14.1.4.3 Conclusions ge (gaj$ct ps ', Because of the procedure involved in the lution process, an inadvertent dilution is considered to b highly unlikely. Nevertheless, coolant does occur, numerous alarms and ind if an unintentional dilution of boron in the reactor ations are available to alert the operator to the condition. thermore, the maximum reactivity addition due to the dilution i slow enough to allow the operator to determine the cause and ake corrective action before shutdown margin is lost. UWlohh dor % reh*W ba4 6ce.= peuloded the.op. c.d mMsi . -v em m*el / v br e.s e de pest <4/c ddJ4 f6 gy 14.1.5 Partial Loss of Forced Reactor Coolant Flow 14.1.5.1 Identification of Causes and Accident Description A partial loss-of-coolant flow accident can result from a mechanical or electrical failure in a reactor coolant pump, or from a fault in the power supply to the pump. Each RCP is supplied by a separate bus. If the reactor is at power at the time of the accident, the immediate effect of loss-of-coolant flow is a rapid increase in the coolant temperature. This increase could result in DNB with subsequent fuel damage if the reactor is not tripped promptly. This event is classified as an ANS Conditio'n II incident. The necessary protection against a partial loss-of-coolant flow accident is provided by the low primary coolant flow reactor trip which is actuated by two out of'three low flow signals in any reactor coolant loop. Above approximately 30 percent power (Permissive 8), low flow in any loop will actuate a reactor trip. Between approximately 10 percent power (Permissive P-7) and the power level corresponding to Permissive P-8 low flow in any two loops will actuate a reactor trip. Above P-7, two or more RCP 14.1-15 (ho cr se d W CYd t G )
BVPS-1-UPDATED FSAR P.ev . 12 (1/94) The lowest absolute magnitude of the moderator temperature coefficient (0.0 Ak/F) is assumed since this results in the maximum hot-spot heat flux during the initial part of the transient when the minimum DNBR is reached. Flow Coastdown The flow coastdown analysis is based on a momentum balance around each reactor coolant loop and across the reactor core. This momentum balance is combined with the continuity equation, a pump momentum balance and the pump characteristics and is based on high estimates of system pressure losses. Results Figures 14.1-13 through 14.1-16 show the transient response for the loss of a reactor coolant pump with three loops in operation. Figure 14.1-16 shows the DNBR to be always greater than the safety analysis limit. Since DNB does not occur, the ability of the primary coolant to remove heat from the fuel rod is not greatly reduced. Thus, the average fuel and clad temperatures do not increase significantly above their respective initial values. The calculated sequence of events for the case analyzed is shown in Table 14.1-2. The affected reactor coolant pump will continue to coast down and the core flow will reach a new equilibrium value associated with the two remaining operating pumps. With the reactor tripped, a stable plant condition will eventually be attained. Normal plant shutdown may then proceed. Conclusions The analysis shows that the DNBR will not decrease below the limit value at any time during the transient. Thus, the DNB design basis as described in Section 3 is met and there will be no cladding damage and no release of fission products to the Reactor Coolant System. 14.1.6 Startuo of an Inactive Reactor Coolant Loon 14.1.6.1 Identification of Causes and Accident Description Inge d 15.1.5 1 1 uith Loop S*cp Valvae npan 4 plant is operating with one pump out of service, there reverse hrough the loop due to the pressure rence across the reac sel. The cold leg . rature in an inactive loop is ident c the c eg temperature of the active loops (the reactor core ' I rature). If the reactor is operated at power, t is a temperature cross the steam generator in t etive loop and, with the reverse he hot leg te ure of the inactive loop is lower than the reac inlet temperature. 14.1-17 f pr o p el tO & q ) _-__________--___--_L
BVPS-1 UFSAR Insert No. 2 The plant can be operated in Modes 5 or 6 with an inactive loop in either of two ways. The reactor coolant pump in the inactive loop can be turned off and the plant operated with the loop isolation valves in the normal fully open position. In this case, there is reverse flow through the inactive loop when a reactor coolant pump in any unisolated loop is operated. The plant can also be operated with the loop isolation valves of a loop closed in order to perform maintenance. In this case, there is no flow from the reactor vessel and active loops to the inactive loop. The plant operates much as if it were a plant without that loop. With the isolation valves closed, the boron concentration of the isolated section of the loop may deviate from the boron concentration of the active loops. The plant may isolate a loop only while the plant is shutdown. Analysis has not been conducted for power operation with a loop isolation valve closed. Inadvertent opening of an isolated loop is prevented by (1) requiring that any loop isolation valve movement follow strict procedural criteria, and (2) loop isolation valve operators have their power removed while a loop is isolated. Procedures require that 1) the boron concentration of the isolated loop be verified, and 2) the isolated loop drained and refilled from the Refueling Water Storage Tank or Reactor Coolant system prior to opening the loop isolation valves, returning the loop to service. An isolated loop will be returned to service within 4 hours of the completion of the refilling to ensure that there is no unacceptable boron stratification in the isolated loop. (Proposed Wording) l l
BVPS-1-UPDATED FSAR Rev. 12 tipHy strative procedures require that the unit be brought t load o than 25 percent of full power prior t ing a pump in an inac o in order to brin e loop hot leg temperature closer to the
- emperature. Starting an idle reactor coolant pum ut br .
he inactive loop hot leg temperature ' o the core inlet tempera uld result ' in the lon of cold water into the core which causes a ivity insertion and subsequent power increase. 1 I 14.1.5.1.2 Mith Lcep Step VcIvec C10ced I l
- 11. tha case of the plant operated at reduced power with a ra=cter- l coolant loop ouc vf ravvice and with of one )
of its loops closed there 1 -2v. .rc= the reactor vessel and active loops active loop and the plant operaLo. -"-b ag , if it a unit lacking one loop. p valves in one loop closed, the isolated sect the loop L id cooler than the temperatur
- e active i loops. Administrative ures re at the plant be brought to zero load, the te ^ te - isolated loop brought 3 to within 20*F of ve loops, and the bor tration of '
the iso oop verified prior to opening the loop stop eturning the loop to service.
'T erlocks are provided to ensure that an accidental startup of a isol loop which has a lower temperature or lower on ;
concentra than the core and active loops will be a atively slow event. interlocks insure that flow the isolated loop to the remal of the Reactor Cool ystem takes place through the relief lin passing th d leg stop valve for a period of approximately one u ore the cold leg stop valve can be opened. The flow th relief line is made low (no ; more than 250 gpm) so t e temperatu nd boron concentration in the isolated lo e brought to equilibr 'th the remainder of the syste a relatively slow rate should the inistrative procedur e violated and an attempt made to open s valves I whe e isolated loop temperatures or boron concentratio , wer than that in the core and active loops. j l Interlocks are provided to/ '
- 4. Prevent Opening cf e het leg-4cep ctcp velve unlecc the ,
-ceM-4eg-step valve in-the came Icep is fully closed. '
)
-ae [reventstartingareactorcoolantpumpunless:
- a. The cold leg loop stop valve in the same loop is fully closed, or
, b. Both the hot leg loop stop valve and cold leg loop stop valve are fully open.
- 2. Prevent opening of e ccid Icg etcp velve unlecc l 14.1-18
( Yr o p es e c( CJ e'd s y )
4 i I Rsv. 12 (1/94) BVPS-1-UPDATED FSAR
- 4. The--het leg loop stop valve in the rare loop hac been fully apened-for-at leact 1 hour,-. 1
-b. The bypass valve in the loop hac been opened for at
-4 east i hour,
=c. Flow hac ex4sted through--the relief linc for at ;
-least -1 houn i
- d. The-cold Icg temper-ature ic *tithin 2 0 " F c f the-
--h49 hest acid Icg temperature in the other loopc and
-the hot leg temperature ic within 20"F cf the
-highect het Icg temperature in tt: Other loops.
The interlocks are a part of the Reactor Protection System and include the following redundancy: 1 Two independent limit switches to indicate that a valve is fully open.
~
Two independent limit switches to indicate that a valve is fully closed.
- 4. Two--dif-ferential pressure switcher in each line which-
-bypasccc a cold Icg loop ctop valve to determine that-
--f Icv cxictc in the-14nc . Flow-through the linc 4ndicates+-
-a. The valvec in the line are open.
- b. The pump in the-isoleted loop is runningr The interlocks meet the IEEE 279-1971 criteria and, therefore, cannot be negated by a single failure. -The interlock on het leg
-temperature ic : backup---for the interlock on cold leg temperaturec. Thuc, the eingle failure criterien applies to the -combination-and-not to-each cepar-ately. With the above prot +ot4cn cy c t+m-4nter4ooks7---the-fe-14 swing- -procedure ic necessar W rder to reopen loop step valves once -either-stop valve in-a-loop-hac lef t the fully open pocition.
-1. The ocid log--loep-stop valve muct be full-y-closed before 4hc hot-4eg-stop valve can be retur-ned to its fully open pecition,
- 2. Flow-must have existed from the isoleted portion of the
-system-to- the - re m a i nder-o f-the- sy stem--{ ma x imu m-ra te-4s-apprcximately 250 gpm) for at least i hour t-brough-the-line bypassing the ccid lag stop valve end the icolated-
-loop-and-active locp temperatures-eust-agrec withi." 20 *F
-before-the ccid leg loop stop velve c&n be Opened.
14.1-19 ( Pro (>oses V3o'a's &
- -= _ - - .- . ... -. .
BVPS-1-UPDATED FSAR Rev. 12 (1/04) 14.1.6.2 Analysis of Effects and Consequences I I -c ge,q?Y .1.6.2.1 Method of Analysis l 3 l A detailed digital simulation of the plant, including he , tran er to the steam generators of the active and inactive lo s ! and actor Coolant System flow transit times, is used to udy the tra sient following the startup of an idle pump. l Looo oo Valves Open Assumptions re:
- 1. Initia conditions of maximum core power and reactor -
coolant average temperatures and minimum eactor coolant pressure resulting in minimum initial margin to DNB. These va es are to be consistent th maximum steady state powe level allowed with al but one loop in operation neluding appropriat allowances for calibration d instrument error . The high initial power gives te greatest temper ture difference between the core inlet temperature and he inactive loop hot leg temperature.
- 2. Following the star of th idle pump, the inactive loop flow reverses and cel ates to its nominal full flow _
value.
- 3. A conservatively 1 g (absolute value) negative ;
moderator coefficient asso ated with the end of life. ; i
- 4. A conservatively ow (abso ute value) negative Doppler !
power coefficien is used.
- 5. The initial reactor coolant oop flows are at the appropriate lues for one pump ou of service.
The reactor trip assumed to occur on low c olant loop flow when the power range neutron flux exceeds the P- setpoint. The P-8 setpoint is c servatively assumed to be 7 percent of rated power, which corresponds to the nominal setpoi t plus 9 percent I for nuclear strumentation errors. ; Loon oo Valves Closed , The st rt-up of an inactive reactor coolant loop wi the loop l stop alves initially closed has been analyzed assu ing the inac ive loop to be at a boron concentration of 0 ppm w ile the ac ve portion of the system is at 1,800 ppm, a conserv ively h gh value for beginning of life. The flow through the lief ine is assumed at its maximum value of approximately 250 gpm. - t 14.1-20 ( Pictew word )
1 l l
)
BVPS-1 UFSAR Insert No. 3 I Procedures require that the isolated loop water boron concentration be verified prior to opening loop isolation valves. i Procedures also require an isolated loop to be drained and l refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System within 4 hours of opening either i the hot or cold leg isolation valves. This prevents several potential concerns. A potential single failure of the blender if the Chemical and Volume Control System was used to fill an i isolated loop could lead to unborated primary grade water being injected. Using water from the Refueling Water Storage Tank or Reactor Coolant System ensures that the boron concentration of the isolated loop is sufficient to prevent a dilution of the boron concentration in the active reactor coolant loops which would reduce the shutdown margin to below those values used in safety analyses. Thus, when the isolated loop is returned to service, no single failure could cause an isolated loop to be filled with unborated water. Opening the loop isolation valves within 4 hours of the refill prevents any boron concentration stratification concerns. i 1 (Proposed Wording) l
-_ __ - _ J
BVPS-1-UPDATED FSAR Pev. 10 (1/02)
.1.6.2.2 Results
'th Looo Stoo Valves Open The resu s following the startup of the idle pump, with the loo stop valve initially open are shown in Figure 14.1-22. e minimum DNBR uring the transient is never less than the fety analysis limit. The calculated sequence of events or the accident is shown Table 14.1-2. ,
I With Loop Stoo Valv Closed
~
Even with the assumptio that administr ive procedures are violated to the extent tha an attempt s made to open the loop ; stop valves with 0 ppm in th inact e loop while the remaining ' portion of the system is at 1,8 m, the dilution of the boron in the core is slow. Thegni a reactivity insertion rate is j calculated to be 2.2 x 10~ ok/se nd, considerably less than , the reactivity insertion r es conside d in Section 14.1.2. It j takes 31 minutes after e beginning of e dilution before the ; total shutdown margin lost assuming one pe ent shutdown margin ! at the beginning o the accident. This is mple time for the ! operator to reco Ize a high count rate signal a terminate the i dilution by t ing off the pump in the inact' e loop or by [ borating to e nteract the dilution. l l The re ivity addition at end of life due to an attempt open stop alves when the inactive loop temperature is less tha the co temperature is smaller than the reactivity addit n nsidered in the above beginning of life case. i 14.1.6.2.3 Conclusions g , 'Rith Looo Stoo Valves open Y The tra ient results show that the core is not adv ly considerable margin to affected, e., there is safety , analysis limit. [ With Loon Stoo lves Closed The redundant interlockhsprovide the Reactor Protection System insure that the temperatur boron concentration in an isolated loop are brought to i tum with the remainder of the system at a slow rate. ld admin: rative procedures be violated and an attempt m to open stop lves when the isolated loop t temperatu or boron concentration i lower than that in the core, l the etivity addition rate is slow e ugh to allow the operator } ake corrective action before shutdown gin is lost. l l i b 14.1-21 ( Pre pesrs cJerd $y )
T BVPS-1 UFSAR Insert No. 4 Procedures and interlocks prevent inadvertent opening of loop isolation valves and require that the startup of an isolated loop be performed in a controlled manner. This virtually eliminates any sudden positive reactivity addition from boron dilution. Thus the core can not be adversely affected by the startup of an isolated loop and fuel design limits are not exceeded. (Proposed Wording)
ATTACHMENT D-2 Beaver Valley Power Station, Unit No. 2 Proposed Technical Specification Change No. 95 Applicable UFSAR Changes l l l l l i l _______-_.i
BVPS-2 UFSAR
- b. If the reactor is in the automatic control mode, the multiple failures that result in the withdrawal of a single RCCA will result in the immobility of the other RCCAs in the controlling bank. The transient will then proceed in the !
same manner as described in Case a. . In cases, such as those described in this section, a reactor trip will ultimately ensue, although not sufficiently fast in all cases to , prevent a minimum CNBR in the core of less than the limit value. Following reactor trip, normal shutdown procedures are followed. 15.4.3.3 Radiological Consequences . l The most limiting RCCA misoperation, accidental withdrawal of a single RCCA, is predicted to result in limited fuel damage. The subsequent reactor and turbine trip would result in atmospheric steam dump, assuming the condenser is not available for use. The i radiological consequences from this event are less severe than those of the main steam line break (MSLB) event, analyzed in Section 15.1.5.3 15.4.3.4 Conclusions t For cases of dropped RCCAs or dropped banks for which the reactor is tripped by the power range negative neutron flux rate trip, there is no reduction in the margin to core thermal limits, and consequently ; the DNB design basis is met. For all cases of any RCCA fully inserted, or bank D inserted to its rod insertion limits with any single RCCA in that bank fully withdrawn (static misalignment), the DNBR remains greater than the l limit value. t For the case of the accidental withdrawal of a single RCCA, with the ! reactor in the automatic or manual control mode and initially operating at full power with bank D at the insertion limit, an upper bound of the number of fuel rods experiencing DNB is 5 percent of the total fuel rods in the core. l 15.4.4 Start Up of an Inactive Reactor Coolant Loop l 15.4.4.1 Identification of Causes and Accident Description seles 5 or6 l The plant can be operatedfwithaninactiveloopineitheroftwo , /*ggl pg ways. The pump in the g a turned off and BVPS-2 (/ f operated with the loop M,cgive loop in valves can thebenormal fully open position. dy In this case, there is reverse flow through the inactive loop g 'A d,y) plen* in sire be operated uit' the 1 :p etcp 121 :: :f :n: :f th:
>g 1 rep: :lered. In th!: rece, +k ere ir r^ " ~> fr^- *ka ~=~"a"=1 I
-A
--+ ice Ir^pr tr +'e i-ectifr 1 rep : f the p!: t :p:::::: :::h 2:
if u .mo o y l m.;. i;' only : : 1::;;. Ir thi: ;;;:icn, th: ;;;r: p of :n in;;;in res;;;r w:I n: 1;;p will b; ;;nsidered b;;h fci i Jntert i + 15.4-18 { Preres& wcYa k) i
BVPS-2 UFSAR Insert No. 1 The plant can also be operated with the loop isolation valves of a loop closed in order to perform maintenance. In this case, there is no flow from the reactor vessel and active loops to the inactive loop. The plant operates much as if it were a plant without that loop. With the isolation valves closed, the boron concentration of the isolated section of the loop may deviate from the boron concentration of the active loops. The plant may isolate a loop only while the plant is shutdown. Analysis has not been conducted for power operation with a loop isolation valve closed. Inadvertent opening of an isolated loop is prevented by (1) requiring that any loop isolation valve movement follow strict procedural criteria, and (2) loop isolation valve operators have their power removed while a loop is isolated. Procedures require that (1) the boron concentration of the isolated loop be verified, and (2) the isolated loop drained and refilled from the Refueling Water Storage Tank or Reactor Coolant System prior to opening the loop isolation valves, returning the loop to service. An isolated loop will be returned to service within 4 hours of the completion of the refilling to ensure that there is no unacceptable boron stratification in the isolated loop. f (Proposed Wording)
l l l BVPS-2 UFSAR l 1 c Fe of the leep step valves initielly cpes *"d fer the care of the ! -1 cop-stcp valves initially cic;cd. ) 15.4.4.2 Assumptions and Method of Analysis
- 1. Loop Stop Valves Initially Open If e plant is operated with the pump in one loop turned off a with t e stop valves open, there is reverse flow through the lo .
The co leg temperature in the inactive loop is identical to the ! cold leg emperatures of the active loops and to the reactor core l inlet tem rature. If the reactor is operated at power, the e is a ! temperature rop across the steam generator in the inactive op and, ! with the re erse flow which exists, the hot leg temperat e of the [ inactive loop lower than the reactor core inlet temper ure. : Administrative p cedures will require that BVPS-2 b brought to a i load of less than 2 percent prior to starting a pump n an inactive loop in order to b ng the inactive loop hot leg t . perature closer } to the core inlet temp rature. The starting of an die RCP without bringing the inactive loop hot leg temperatur closer to the core inlet temperature would r sult in the injection f cold water into [ the core. The cold wa r causes a rapi reactivity and power ; increase. , The following assumptions are de: . i
- a. Following the start of t idl pump, the inactive loop flow accelerates linearly to it n inal full flow value.
P
- b. A most negative moderat temperature coefficient (see ;
subsection 15.0.4). ;
- c. A least negative D pler on1 power coefficient (see f' Figure 15.0-2).
- d. The reactor is ssumed to be init all'y at 67 percent of 2,660 MWt, with he secondary side all three steam l generators at e same pressure and reve se reactor coolant ,
flow through t e idle loop steam gener tor. 67 percent - power is a conservative value assumed or the maximum f steady-stat power level allowed with two loo s in operation ( and inc1 des 2 percent allowance for ca bration and i instrume errors. The high initial power assumed is ! conserv tive since it gives the greatest mperature I diffe nce between the core inlet temperature and the j inac ive loop hot leg temperature. ; i
- e. initial average temperature in the active loops at l e nominal full power value +4*F. This is a conservatis ly ,
high value for the initial average temperature includi i
+ t 15.4-19 ,
h
-__ f
1 BVPS-2 UFSAR instrument errors and results in the minimum margin to cor DNB limits.
- f. e initial RCS pressure is at the nominal value oinus 3 psi. This is a conservatively low value for the nitial pre sure including instrumentation errors and resul in the mini um margin to core DNB limits.
- g. The in tial reactor coolant loop flows are t the values with one ump turned off and two pumps runnin .
- h. The reacto trip is assumed to occur o low coolant loop flow when th power range neutron flux e eeds the P-8 set-point. The -8 set point is conserv ively assumed to be 79 percent of r ted power, which corr ponds to the nominal set-point plus 9 ercent for nuclear instrumentation errors.
A detailed digital simula on of BVPS-2 including heat transfer t6 the steam generators of the ac ive loops nd the inactive loop and RCS loop flow transit times was used to tudy the transient following the start up of an idle pump. I
- 2. Loop Stop Valves Initia11 Closed If the stop valves in one lo are losed, the isolated section of the loop could cool down below he temp ature of the active loops. ,
Administrative procedures quire that he plant be brought to zero i load, the temperature of th isolated loop rought to within 10*F- of l the active loops, and e boron concentr ion of the isolated loop verified to be greater an or equal to he active loop boron concentration prior to pening the loop stop v ves and returning the loop to service. Interlocks are p vided to ensure that an accide al start-up of an isolated loop w ich has a lower temperature o lower boron concentration an the core and active loops will be a relatively slow transien . The interlocks ensure that flow from the isolated loop to the emainder of the RCS takes place through th relief line bypassing e cold leg stop valve for a period of over 0 minutes before t cold leg stop valve can be opened. The flow rough the relief ne is made low (no more than 237 gpm) so hat the temper ure and boron concentration in the isolated loop are rought to e 111brium with the remainder of the system at a relatively slow rat should the administrative procedures be violated and an at empt m e to open stop valves when the isolated loop temperature or b -on ncentration is lower than that in the core and active loops. Interlocksareprovidedtog
- e. Prevent epening ef a het leg Ice; step relve unle:: th: : Id ,
leg 1::p :::p v:17: in th :::: 1::p i fully :1:::d. 15.4-20 I h
, __ ' " " - J ju_ BVPS-2 UFSAR l
-h, ,[reventstartingaRCPunless: l ,
i I
- 1. The cold leg loop stop valve in the same loop is fully closed, or
- 2. Both the hot leg loop stop valve and cold leg loop stop ,
volve are fully open. l I r_ . D_ _c o_ u_ o_ n n e_ n, e n 4 n -- o nf- en n_1_ A 1_ n e innn , cenn, valve un1nce.
- 1. Th het leg 1;;p :::p velv: in the :::: 12 p her bee- .
c.
.. 2. ,. . ., , . . _..
_ .. o.n. _4-m.+._._.
- 2. The hype:: 2:1ve in th leap h: heen cpened for c"er 90 air.utes.
- 3. F1 N h: nisted thr ugh th: : lief line for ever 90
-in"ter.
- 4. Tt: ccid 1 g tc;per ur; is u; thin 20 F cf the '.igh;;t Id leg :::p:reture in th: Other Icep: and the het leg ,__
2_. . 2 . ..t. ... 2 _ , n. or. _,
.. .t..._
t.2._t..__....t..._.. ... t;;p;r:tur; in th: :ther 12:p:. The interlocks are a part of the RPS and include the following redundancy:
- a. Two independent limit switches to indicate that a valve is fully open. l
- b. Two independent limit switches to indicate that a valve is fully closed.
a4sr..mme_4 1-- m.m..m_._. .1. ., 4 + _ w . _4 .- mew 1_ .4 - m . .x. _4 _ w _ m_ m.. m. --. ---- ,_- - . . - - . -- . c,~. k_ u, n, e ._ _ ._ o_ r m_ i_ a_ 1 _ ,- 1.__, .+_-m.e1....
.. , . +.
. a.+..._- -.-.2.-. .u...-..
enists in the line. Flee through the line indic:ter:
, . . , . _ _ 2_
.. e. t. . ._ .... ...t.._. . $.2__.... .-.-
-2 . The purp ir the iceleted Ice; is run-ing.
4 interlocks meet the IEEE Standard 279-1971 criteria and, I The therefore, cannot be negated by a single failure. Th: 'nterlech en > het leg temp : tur; i; 50: hup f:: th: inter 10 h :n 2:1d leg temper &ure:. Thu , th: :!ng1: failur crit:rien applic: te the cochinati:n :nd n:t t: ::ch ::per:tely. . I w I aC w; ^.' [r; C I CN [:ICC nICI.; Cy C ..CN.ng [IOSe Ur0 4: ne er: ry in erder-te :::p:n 1 p :tcp ::1v : cn : cither ::cp , velve in Icep her left the fully epen peritien- , 1 15.4-21 (h
BVPS-2 UFSAR a\.The cold leg loop stop valve must be fully closed before t n g leg stop valve can be returned to its fully pen posin n. i l
- b. Flow must e existed from the isola portion of the system to the re.. nder of the system ximum rate is 237 gpm) for over 90 minh s through t ine bypassing the cold ;
leg stop valve, and th iso ed loop and active loop l temperatures must agree thin 20*F before the cold leg loop stop valve can be ened. l The start-up of inactive reactor coolan oop with the loop stop valves init ly closed has been analyze assuming the inactive lo to be at a boron concentration of 0 p while the ; active ion of the system is at 1,742 ppm, a conser ively l high *alue for beginning-of-life. The flow through the rett f e is assumed at its maximum value of 237 gpm. l Results 4 ggg,, e+ J2 Loop Stop Valves Initially Open The resu ts following the start-up of an idle pump with the ab e listed ass tions are shown in Figures 15.4-16 through 15.4-20. The l neutron flux increases to the trip point (assumed to be 79. rcent) I in 7 seconds. e thermal flux response, of interest for DSB considerations, dicates that the peak average therm heat flux l reaches the nomin value at 8 seconds. The re average i temperature, core i et temperature, RCS pressure and DNBR during the transient are also own. The minimum DNBR du ng the transient has been calculated to be .18 and occurs at 7.5 econds.
- 2. Loop Stop Valves Ini ally Closed Even with the assumption that ad nist tive procedures are violated j to the extent that an attempt is ma o open the loop stop valves !
with 0 ppm in the inactive loop - e the remaining portion of the system is at 1,742 ppm, the dilu on of he boron in the core is slow. The initial reactivi inserti rate is calculated to be
~
1.77 x 10 ' k/sec, consider ly less than t reactivity insertion rates considered in Sec ons 15.4. 1 and 15.4. . It takes more than 17.4 minutes after the eginning of the dilution before the total shutdown margin is lost. This is ample time the operator to recognize a high c nt rate signal and terminate t e dilution by ; turning off t pump in the inactive loop or b borating to j counteract th dilution. The above results consider dilution - transient d ing power or start-up with loop stop valves el ed. l The re tivity addition at end-of-life due to an attempt to ope stop ; valv when the inactive loop temperature is less than the re te erature is smaller than the reactivity addition considered in t ove beginning-of-life case. 15.4-22 h
BVPS-2 UFSAR Insert No. 2 _ l l
\
Procedures require that the isolated loop water boron concentration be verified prior to opening loop isolation valves. Procedures also require an isolated loop to be drained and refilled with water supplied from the Refueling Water Storage Tank or Reactor Coolant System within 4 hours of opening either the hot or cold leg isolation valves. This prevents several potential concerns. A potential single failure of the blender if the Chemical and Volume Control System was used to fill an i isolated loop could lead to unborated primary grade water being injected. Using water from the Refueling Water Storage Tank or Reactor Coolant System ensures that the boron concentration of the isolated loop is sufficient to prevent a dilution of the boron concentration in the active reactor coolant loops which would reduce the shutdown margin to below those values used in safety analyses. Thus, when the isolated loop is returned to service, no single failure could cause an isolated loop to be filled with unborated water. Opening the loop isolation valves within 4 hours of the refill prevents any boron concentration stratification concerns. 1 (Proposed Wording) I
._ . - _ - . ~. - _ _ BVPS-2 UFSAR ' i 15.4.4.3 Radiological Consequences There are only minimal radiological consequences associated with i start-up of an inactive reactor coolant loop. Th: ::::::: trip
- turb!-- trip, and heet !r --~ fed fr^- +k- r--^ dery ryrter .
.t.~.n .t. .+m._ ,--_..+m. -~....14.c m o i . .. . m. ..r.+o .. 1--.
bince no fuel damage is postulated to occur from this transient, the ! radiological consequences associated with this event are less severe i than the loss of nonemergency ac power to the station auxiliaries , described in Section 15.2.6. j 15.4.4.4 Conclusions ' I"#"#'3 h5: tr ::irnt ::: ult f:: th: :: rt ; cf : in :tiv: ;;;;t:r ;;;1;;; 1::p cith the Irr; stry felfr: initfrily rper r'~ +'et +' r-4- e t
- id;r:51: r;in tr : Idritin; DMSP cf 1.? Y!th th: 1:rp-e6ep <
! :: initielly :Ir :d, the redundert inter!rch prrcid:d in th RPS !
---"re +'r* +k- +- peretur- and berer cerrentretirr ': 12 i::!:::d -
1erp ::: Err";'t te equilibrirr eith the rrreinder rf th: 17:::: et :
-!: ret . Th: ::: lt: prz:::::d th::: her the tir: :::11:51: f;r th: :p ::t;r :: ;_;;;11y 0;r;in :: th; ;; .;; ;f the dilutier. f1;.
. u ~_ _. , a_ s..
.2_a__a.._._..__a...._ 7._____...- t..- ...,....,-um.
-u . ..y. ..u. uv ,
- p: :te; ::1::: rh:2 the 1:rlated irr; t- pereturr ^r beren
{ ren:::tretic: 1: 1: :: th:2 th:t in th: ::::. T:11:_-in; rsin;;i;; ~ a r + k-dil"+!^- fl~ , t'e r;rreter : initirt: ::i:::ti:n :: r;;...; t he r '"* d~~ --*:4- The radiological consequences of this event.are not limiting. ; I 15.4.5 A Malfunction or Failure of the Flow Controller in a Boiling Water Reactor Loop that Results in an Increased Reactor Coolant Flow Rate This section applies only to BVRs and is not applicable to BVPS-2. 15.4.6 Chemical and Volume Control System Malfunction that Results ! in a Decrease in the Boron Concentration in the Reactor ' Coolant 15.4.6.1 Identification of Causes and Accident Description One of the two principal means of positive reactivity insertion to the core is the addition of unborated, primary grade water (PGW) into the RCS through the reactor makeup portion of the CVCS. Boron dilution with these systems is a manually initiated operation under i strict administrative controls requiring close operator surveillance with procedures limiting the rate and duration of the dilution. A boric acid blend system is available in the CVCS to allow the j operator to match the makeup's boron concentration to that of the RCS during normal charging. The principal means of causing an inadvertent boron dilution are the opening of the PGW makeup control valve and failure of the blend 15.4-23 (Paesacac<df)
i BVPS-2 UFSAR Insert No. 3 Procedures and interlocks prevent inadvertent opening of loop isolation valves and require that the startup of an isolated loop be performed in a controlled manner. This virtually eliminates any sudden positive reactivity addition from boron dilution. Thus the core can not be adversely affected by the startup of an isolated loop and fuel design limits are not exceeded. l l (Proposed Wording)
~3 '
BVPS-2 UFSAR "?" 2 system, either by controller or mechanical failure. The reactor , makeup portion of the CVCS is designed to limit, even under various , postulated failure modes, the potential rate of dilution to values which with indication by alarms and instrumentation, will allow sufficient time for operator response to terminate the dilution. An inadvertent dilution from the reactor makeup portion of the CVCS may be terminated by closing the PGW makeup control valve. All expected sources of dilution may be terminated by closing the volume control tank isolation valves 2CHS*LCV115C and E. The lost shutdown margin (SDM) may be regained by opening the refueling water storage tank (RWST) isolation valves 2CHS*LCV115B and D, thus allowing the addition of 2000 ppm borated water to the RCS. Th: dditi:- :: : :f ;-h:::t:" cator : the "fE, UF- th: :::!d :1
'12 : ::::;;I (""") systr- i: cp::: ting, i: Ifrit d by : flew i rec t -ic t !r- de" ice Thir = A-in d - t r at i"e ly certrelled de" ice "ill 1mi i' s m kmup fleu during :sid chutdcur nd during h:t :h td:ra A
t h e " U" ryrter ir in ^^^re+4^= 4 + k +ba =+-= r- :=a--=+^* hadng
- d i: :---;; decryErrt,'[hemaximn=dilutionrate is limited by ,
the capacity of the charging /high head safety injection (SI) pumps. L Generally, to dilute, the operator must perform two distinct actions:
- 1) Switch control of the makeup from the automatic makeup mode to the dilute mode, and ,
- 2) Depress the start button. .
Failure to carry out either of the above actions prevents initiation of dilution. Also, during normal operation the operator may add borated water to the RCS by blending boric acid from the boric acid storage tanks with PGW. This requires the operator to determine the concentration of the addition and to set the blended flow rate and
~
the boric acid flow rate. The makeup controller will then limit the sum of the boric acid flow rate and PGW flow rate, to the blended i flow rate i.e. the controller determines the PGW flow rate after the start button is depressed. The status of the RCS makeup is continuously available to the operator by:
- 1) Indication of the boric acid and blended flow rates,
- 2) CVCS and PGW pump status lights,
- 3) Primary grade water header low pressure alarm,
- 4) Deviation alarms if the boric acid or blended flow rates deviate by more than 10 percent from the preset values, 15.4-24
( Prepo se ef W rf d h
~ 4fI BVPS-2 UFSAR l
- 5) Source range neutron flux - when reactor is subcritical; ) 1 a) High flux at shutdown alarm, ;
b) Indicated source range neutron flux count rates, and l l c) Audible source range neutron flux count rate , 1
- 6) With the reactor critical; a) Axial flux difference alarm (reactor power 2 50 percent), I b) Control rod insertion limit low and low-low alarms,
{ c) Overtemperature AT alarm (at power), f d) Overtemperature AT turbine runback (at power), l e) Overtemperature AT reactor trip, and i i f) Power range neutron flux - high, both high and low set point reactor trips. This event is classified as an ANS Condition II incident (a fault of i moderate frequency) as defined in Section 15.0.1. 15.4.6.2 Analysis of Effects and Consequences i To cover all phases of BVPS-2 operation, borcri dy WL *.lon during the ; modes of refueling, cold shutdown, hot shutdoms, bot ntandby, start-up, and power is considered in this analysl3 Conservative values boron for necessary parameters were used, (high RL: critical concentrations, high boron worths, minimum shuticsn margins, and lower than actual RCS volumes). These assumptions result in conservative determinations of the time available for operator : response after detection of a dilution transient in progress. Dilution During Refueling , cel/ skufJ,osa s. 4 #.f s h of cLe oa rc M M Y * !m "ncentrelled her:: diluti ::nzi;;; ;;..;.st ;;; . L.i . LL;a , rrd: Of rp :2!!?r. Irr91:rtert 'ilr*irt i: pr;;;;t:d by ; rdriniet:2t!ze errtr:1: chich i::1::: th; nce f;;; :h; p;;; ;;;l i
- Of :S:::ted r:ter. f.ny ::h::p chi;h i; ;;;;ir;d d;;ir.; ,
r-f" eld : rill be heret:d :::: : ppli d fr;; :h. 2.'OT L, LL 1 he-d s afety inje-+ f a- p" pr. I tilutic: Durin: celd e'-* d~ r Th.: T::Enic-1 "; 264derti rr require the reerter te he rh"tdeer by et 1:::t
...-__2 1 percent
<_.4.2.....
ih/F ".hrn in this t-___ rede. The fc11eed : c^ Afti^=- ere 244utge. 2333 i. 333. _7___ 1 ; ;g : I 15.4-25 l l ( Pre p u s w & . p )
i BVPS-2 UFSAR Insert No. 4 An uncontrolled boron dilution transient cannot occur during this mode of operation. The primary means for a significant boron i dilution is through the injection of unborated water into the i Reactor Coolant System. Inadvertent boron dilution is prevented ! by administrative controls which isolate the primary grade water system isolation valves from the Chemical and Volume Control System, except during planned boron dilution or makeup activities. Thus unborated water can not be injected into the Reactor Coolant System, making an unplanned boron dilution at these conditions highly improbable, since the source of unborated water to the charging pumps is isolated and the low head safety injection pumps can not be aligned to the primary grade water supply. This precludes the primary means for an inadvertent boron dilution event in this mode of operation. The primary grade water system isolation valves may be opened when directed by the control room during this mode of operation only for a planned boron dilution or makeup activity. The primary grade water system isolation valves will be verified to be locked, scaled or otherwise secured in the closed position within 15 minutes after the planned boron dilution or makeup activity is completed. During planned boron dilution events, operator attention will be focused on the boron dilution process and any inappropriate blender operation is unlikely and will be : readily identified. The operator has prompt and definite indication of any boron dilution from the audible count rate instrumentation. High count rate is alarmed in the reactor containment and the control room. In addition a high source range flux level is alarmed in the control room. The count rate increase is proportional to the ' suberitical multiplication factor. i (Proposed Wording)
A
- m. , m
~ ~
BVPS-2 UFSAR l l The maximum boron concentration : quired to meet a SDM of ' ercent Ak/k is conservatively estimated to be 1600 ppm. s rresponds to a critical C of 1520 ppm, assumi a 3 con rvative, constant boron worth of 12.5 pcm/ ppm.
- 2) Dilutio flow is limited by administrative cont 1 to an approxima flow rate of 85 gpm unborated water. l
- 3) A minimum S water volume of 7500 ft'. This a conservative I estimate of th active volume of the RCS w all loops in l service, minus t pressurizer volume. ;
)
When the RCS is in a artially drained co ition, or in less than l three loop operation when cold shutdown, he PGW supply will be l administrative 1y controlled. ' i Dilution During Cold Shutdown W1 Lo Stop Valves Closed ) The following conditions are ed for an uncontrolled dilution- l during cold shutdown with one se of op stop valves closed: l [
- 1) Initial boron concentr ion, boron rth, and dilution flow are [
the same as the cold s tdown case with 11 loops in service. l t 8
- 2) A minimum RCS wa r volume of 6237 This is a very conservative esti te of the active. RCS vo e with one loop i out of service, inus the pressurizer volume. !
The following onditions are assumed for an uncont 11ed dilution l during cold s down with two sets of loop stop valves c sed: [
- 1) Initia boron concentration, boron worth, and dilution low are the me as the cold shutdown case with all loops in serv 2 .
- 2) minimum RCS water volume of 4974 ft'. This is a ry !
conservative estimate of the active RCS volume with two loops o ; of service, minus the pressurizer volume. Pil:M:n Du ; "r
- c5m + d ~~ :
Technical Specifications require the reactor to be shutdown b i less 77 percent Ak/k when in this operating mode. The owing condition 'ere assumed for an inadvertent boron dil n while in this mode:
- 1) The maximum boron entration r red to meet a SDM of 1.77 !
percent Ak/k is conservat s mated to be 1600 ppm. This ! corresponds to a cri of 1455 ppm, assuming a , conservative, cons boron worth of . cm/ ppm.
- 2) Dilution 4ow is limited, by administrative trol, to an app mate flow rate of 85 gpm unborated water.
15.4-26 (Prfe><du>weaQ o
" ~
BVPS-2 UFSAR j i i
- 0) 4 miulmum IiC3 wuici .vlumu vf 7000 fi' Thio . wvuos iut i'ia est # -ate of th: :: tic; c 1;;; cf th "CC.
""" '^^"
';1 _ . . i; :p;r tin; nd the "CE 1^rr t'er *b""- sp;;;ti:n, th: PC';.' :_; ply i: th: fr in theroin; Jill b^
)
pur;- ' amm u ;.stic;Iy : .tz:11:d. Dilution During Hot Standby The Technical Specifications require the reactor to be shutdown by at least 1.77 percent Ak/k when in this operating mode. The following conditions were assumed for an inadvertent boron dilution while in this mode: , i i
- 1) The maximum all rods in critical boron concentration is conservatively estimated to be 1,500 ppm. The minimum change from the critical boron concentration assuming all rods in and l 1.77* shutdown margin is conservatively estimated to be 135 ppm.
- 2) DiIntion flow is the maximum capacity of two charging /high head SI pumps with RCS at 2,250 psia (approximately 231 gpm).
( i t t i t 15.4-26a l f 1
BVPS-2 UFSAR
- 1) Dilution flow from two charging /high head SI pumps is at the maximum at an RCS pressure of 2250 psia (approximately 231 gpm) when the reactor is in manual control. When in automatic control, the dilution flow is the maximum letdown flow (approximately 120 gpm).
- 2) A minimum RCS water volume of 7951 cubic feet. This active volume includes the reactor vessel volume, reactor coolant loop piping volumes and the primary steam generator volume.
Specifically excluded are the pressurizer and pressurizer surge line volumes.
- 3) The initial boron concentration is assumed to be 1800 ppm, which is a conservative maximum value for the critical concentration at the condition of hot zero power, rods to the insertion limits and no Xenon.
- 4) The critical boron concentration following reactor trip is assumed to be 1500 ppm, corresponding to the hot zero power, all rods inserted (minus the most reactive RCCA), no Xenon condition.
The 300 gpm change from the initial condition noted above is a conservative minimum value. Results Dilution During Refueling, csed shA18 A d M shddeu/n. these. Dilution during this modes has been precluded through administrative control of valves in the possible dilution flow paths, see Section 15.4.6.2. Dilution During C !d Ehuid:rr, " t chutdcr- crd Hot Standby In the event that an inadvertent boron dilution transient occurs while in $dd'5 5 modef, the operator will be alerted to the transient by the primary grade water header low pressure alarm, by the boric acid or blended flow rate deviation alarms, by increasing audible and indicated count rate on the source range instruments, and by the high flux at shutdown alarm. The time available for operator action during this sequence is at least 15 minutes. Thus, the operator will be able to terminate this accident prior to loss of shutdown margin. Dilution During Startup This mode of operation is a transitory mode to go to power and is the operational mode in which the operator intentionally dilutes and withdraws control rods to take BVPS-2 critical. During this mode BVPS-2 is in manual control with the operator required to maintain a very high awareness of plant status. For a normal approach to criticality the operator must manually initiate a limited dilution 15.4-28 ( p upes-d ed eOg}}