PM-92-108, Rev 2 to Plant Mod PM 92-108, Cbeaf Improvements
| ML20128H734 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 01/08/1993 |
| From: | CAROLINA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20128H699 | List: |
| References | |
| PM-92-108, PM-92-108-R02, PM-92-108-R2, NUDOCS 9302170144 | |
| Download: ML20128H734 (24) | |
Text
. _ _ _ - _ _ _ - - _ _ _ - _ -
ATTACliKENT 2 (Cont
- d)
OtLD RCV. NO.
E PAGE R C4 KEVISION 3 10CFR50.59 PROGRAM MANUAL Pcgo 55 AITACIMENT A
'CP&L SAFETY REVIEV PACKAGE Page of SAPITY REVIEV COVER SHEET DOCUliENT No. M @ *1 8 REV. NO.
2.
t DESCRIPTION OR TITLE: cSEAP IMPRav'EvtNTS 1.
Assigned Responsibilities:
Safety Analysis Preparer!
.@. b M Lead 1st Safety Reviewer:
hl.D. SM ITt4 7
2nd Safety Reviewer:
C.R. M1*C 4%
2.
Safety Analysis Preparer! Complet ART
,S ANALYSIS Safety Analysis Preparer
/6" M
/
l** 7 " 9 3
/
yu u,u.
um 3.
Lead 1st Safety Reviewer: -Complete Part II. Item Classification.
4 Lead 1st Safety Reviewer:
Part III may be completed.. If either question 1-or 2 is 'yes.' then Part IV !s not required.
5, t.ead 1st Safety Reviewer: Determine which DISCIPLINES are required for revies of this ites (includin5 own) and mark the appropriate block (s) below.
DISCIPLINES Reauiredt (Print Name)
Sirnature/Date (Stee M i
() Nucitar Plant Operations
() Nuclear Engineering 5 Mechanical i HVAC, Dderak L No r b--
322Wdll.2AM" g E1.etrical Lius J 4 M L UM
- /*M,
E Instrumentation & Control N.SMITL4
^ [EM F77.1 E Structural d
Cois
,d 4f, /-8 9
() Metallurgy
() Chemistry / Radiochemistry
() Health Phys'ics
() Administrative Controls 6.
A QUALITIED SAFETY REVIEVER will be-assigned for each DISCIPLINE marked in step 5 and his/her name printed in the space provided. Each person listed shall perform a SAFETY REVIEV and provide input into the Safety Review Package.
i 7.
the lead 1st Safety Reviewer vill assure that a Part !!1 or Part IV is completed (see step 4 above) and a Part VI if required (see 9.d of Part II).
Each person listed in step 5 shall sirn and nate next to his/her name in step 5 indicating completion of a SATETY REVIEW.
8, 2nd Safety Reviewer: Perfgo a'SAPITY RZviEV in accordance with Se cion 8.0, 2nd Safety Reviewer OTN&Ns Date %
9I DISCIPLINE:
YN PNSC review required? If 'yes,' attach Part V and mark reason-111 E2' below:
E
()
Potential UNREVIEVED SAFETY QUESTION
-Question 9 of Part IV answered.*Yes*
I other (specify): 'TECLJhllCAL. c.aciFicAOoM dlAMCE 0 AI 109 Rev 002 rage 7 2 ot co-i 9302170144 930200 j
PDR-ADOCK 0500 3 P.
. _ ~ _ _.
ATTACRMENT 2 (Oont'o)
I' M M OD. E _ S ' l O b FitLD REY. M _- E f
c5 PME R l
REVISION 3-10CFRSO.59 PROGRAM MANDAL-Page $6 i
ATTACHMINT A
-l
~
CP&1 SAFETY REVIEV PACKAGE Page of i
PART 1: SAFETT.A R.LTkIS (See instructions in Section 8.4.1) i (Attach additional sheets as necessary.)-
DOCWENT NO. M %.106 ggy, go, 2
DESCRIPTION OF CHANCE:
bR ANJ4ED OBCmpf)0d i
~
ANALYSIS:
M MTfbCMfO UdW $ $
i
'l t
I
?
i
.h P
r i-Y RETERENCES:
IEE Of1Ps.4fO kiFENE4C4$
1 O A1:109 Rev 002
~ Page 73 of 86
].
M t C00.NO, M " M ATTACHMENT 2 (Cont'd) fl[LD REY. N(L O
f1,CE N(L.
REVTSION 3 10CTR50.59 PROGRAM MANUAL Page 57 ATTACHMENT A CP&L SATETt REVIEV FACKAGE Page of PART II: ITDI CLASSITICATION DOCUMENT NO. hb* Db REV. NO.
2a 111 En 1.
Does this item representi a.
A change to the facility as described in the SATETY g
[]
ANALYSIS REPORT 7 b.
A chan6e to the procedures as described in the SATETt
[]
3 ANALYSIS REPORT 7 c.
A test or experiment not described in the SAFETt
()
3 ANALYSIS REPORT 7 2.
Does this item involve a change to the individual plant g
()
Operating License or to its Technical Specifications?
3.
Does this item require a revision to the PSAR7 3
()
4 Does this item involve a change to the Off. Site Dose
[1 3
Calculation Manual?
5.
Does this item constitute a change to the Process Conttol
()
g Program?
6.
Does this item involve a major change to a Radwaste Treatment (}
g System!
7.
Does this item involve a change to the Technical 3
(]
Specification Equipment List (BSEP and SHNPP only)?
6.
Does this item impact the HPDES Permit (all 3 sites) or
()
E constitute an "unreviewed environmental question" (SHNPP Environmental Plan, Section 3.1) or a "significant environmental impact" (BSEP)?
9.
Does this item involve a change to a previously accepted:
a.
Quality Assurance Program 3
b.
Security Plan (including Training, Qualification, and R
Contingency Plans)?
c.
E d.
Independent Spent Tual Storage Installation licensef R
(If "yes," refer to Section 8.4.2, " Question 9,"
for special considerations. Complete Part VI in accordance with Section 8.4.6)
SEE SECTION 8.4.2 TOR INSTRUCTIONS FOR EACH "YES" ANSVER.
REFERENCES. List TSAR and Technical Specification references used to answer questions 1 9 above.
Identify specific reference sections used for any "Yes" (EE 4tttc4EQ 2EFU EVtE E 0 AI 109 Rev. 002 Page 77. oi 116
PLANT N0a no. 92 108 ATTACIMENT 2 (Cont'd)
'l-Fl[LDPtV.Na PAGE NO.
C7 REVISION 3 10CFR50.59 PROGRAM MANUAL Page 58 ATTACliKENT A CPE SATETY REVIEV PACKAGE Page of PART III: UNREVIEVID SATETT QUESTION DETERMINATION SCPIEN DOCUMUTT ::0. b M*l@
RIV. :;0.
1.
Its
- '2 1.
Is this change 19112 addressed by another completed
()
3 UNREVIEVED SATETY QUESTION determination? (See Sections 7.2.1, 7.2.2.5, and 7.9.1.1)
RETE 7.IliCE DOCUMENT:
REV. :;0.
111 22 2.
For procedures, is the change a non intent change which gnly (check all that apply):
(See Section 7.2.2.3)
()
()
()
Corrects typographical errors which do not alter the teaning or intent of the procedure; or,
[]
Adds or revises steps for clarification (provided they are consistant with the original purpose or applicability of the procedure); or,
()
Changes the title of an organizational position; or,
[]
Changes names, addresses, or telephone numbers of persons: or,
()
Changes the designation of an item of equipment where the equipment is the same as the original equipment or is an authorized replacement; or,
()
Changes a specified tool or instrument to an equivalent substitute; or,
[]
Changes the format of a procedure without altering the meaning, intent, or content; or
[]
Deletes a part or all of a procedure, the deleted portions of which are wholly covered by approved plant procedures?
If the answer to either Question 1 or Question 2 in PART III is "Yes," then PART !V need not be completed.
O AI 109 Rev. 002 Page 75 of 86
ATTACHMENT 2 (cont'd)
PLANT M00. #0. %. )OB l
b Il[LD RCV. M l
PMt M CO i
i REVISION 3 10CFR50.59 FROGRAM MANURL Page 59 i
ATIACHMENT A l
~
CF&L $ dETY REVIEW PACKAGE Page of 1
FART IVt UNREVIEVED SAFETT QUESTION DETERMINATION DOCUMENT NO. M 8l1- [0$
ggy, go, _ 2,
{
t Usin5 the SATETY ANALYSIS developed for the change, test or experiment, as well as other required references (LICENSING BASIS DOCUMENTATION, Design Drawings Design i
+
Basis Documents, codes, etc.), the preparer of the Unteviewed Safety Question Determination must directly answer each of the following seven questions and make a determination of whether an UNRIVIEVED SATETY QUESTION exists.
A VRITnN RASIS IS RIQUIIID TOR EACH ANSVER I
11.1 E2 1.
May the proposed activity increase the probability cf
[]
g occurrence of an accident evaluated previously in the SATETY ANALYSIS REPORT 7
$EE 4TTACMEQ t
2.
May the proposed activity increase the consequences of an
()
5 accident evaluated previously in the SATETY ANALYSIS RIFORT1 BEE b M @
_[
3.
May the proposed activity increase the probability of
[]
E occurrence of a malfunction of equipment important to safety evaluated previously in the SATEIT ANALYSIS REPORT 7 CeE MED 4
May the proposed activity increase the consequence of a
[],
E.
malfunction of equipment important to safety evaluated previously in the SAFETY ANALYSIS REPORT 7 SEE MEO 1
5.
May the proposed activity create the possibility of an
[]
E accident of a different type than any evaluated previously in the SAFETY ANALYSIS, RT7 WE AMOAEO e
O AI 109 Rev. 002 Page-76-of 86
-[.
4
~. ~., _. _ _ _. _..
,gg ATTACHMENT 2 (Cont'd) fitLD REY. M E
/ ACE NO.
O REVISION 3 10CFR50.59 PROGRAM MANUAL Page 60 ATTACHMFEt A CP&L SAFETY REVIEW PACKACE Page of FART IV:
(Continued)
DOCUMENT NO. M @ l0 D REV. NO.
Z In th 6.
May the proposed activity create the possibility of a
[]
3 malfunction of equipment important to safety of a different type than any evaluated previously in the SAFETY ANALYSIS REPORT 7 EE ANO 7.
Does the proposed activity teduce the margin of safety as
[]
E defined in the basis of any Technical Specification?
hE MNED 8.
Based on the answers to questions 1
- 7. does this item
()
N result in an UNREVIEVED SAFETY QUESTION 7 If the answer to any of the questions 1 7 is "Yes," then the item is considered to constitute an UNREVIEVED SAFETY QUESTION.
- " ~ ~
9.
Is PNSC review required for any of the following reasons?
[]
3 I/, in answering question 1 or 3 "No," it was determined that the probability increase was small relative to the uncertainties; or, in answering question I or 4 "No,"
it was determined that the doses increased, but the dose was still less than the NRC ACCEPTANCE LIMIT; or, in answering question 7 "No,"
a parameter would be closer to the NRC ACCEPTANCE LIMIT, but the end result was still within the NRC ACCEPTANCE LIMIT; then PNSC review is required.
/*
REFERENCES:
Dte Atitc4EO This Unreviewed Safety Question Determination is for the following DISCIPLINE (s):
(Additional Part IV forus may be included as appropriate.)
Nuclear Plant Operations E Structural Nuclear Engineering
,; Metallurgy Chemistry / Radiochemistry I Hechanical 5 Electrical Health Physics Instrumentation & Control Administrative controls 0 AI 109 ev. 002 Page 77 of 86 l
N UM M-@* iOb ATTACHMENT 2 (Cont'd) flILD RtY. E E
PACEft0.,,
CIC)
REVISION 3 10CFR50.59 PROGRAM MANUAL Page 61 AITACHMLNT A CP&l, SAFETY REVIEV PACKACE Page of PART V FNSC REVIEV DOCL' MENT NO. N M-10 6 REv, no, 1 Determination / Evaluation:
.e Action Taksn:
Basis:
PNSC Chairtran:
Date:
O AI 109 Rev. 002 Page 78 of 86
Ptm man, a 4E* LOA ATTACHMENT 2 (Cont'd)
. g PAGE Mi CII REVISION 3 10CFR50.59 PROGRAN MANtTAL Page 62 ATTACHKENT A CPEL SATETY REVIEV PACKAGE Page o f *"
FART VI: ISTSI CHANCES (10CTR72.48)
DOCll KENT NO.
DN REY. 30, d
'l 1.
Dees this item represent:
a.
A change to the Independent Spent Tuol Storage
()
3:
Installation (ISTSI) as described in the ISTSI Safety Analysis Report?
b.
A change to the procedures as described in the
[]-
- 3 ISTSI Safety Analysis Report?
c.
A_ test or experiment not described in the ISTSI
[],
5 '
[
i Safety Analysis Report?
2.
Does-this ites involve a change to the license
()
5, conditions incorporated in the ISTSI Operating License?
3.
Does this item result in a significant increase in
[]
5:
occupational exposure?
4 Does this item result in a significant unreviewed
()-
E environmental impact?
SEE SECTION 8.4.6 TOR INSTRUCTIONS FOR EACH *YES" ANSWER.
RITERENCES. List ISTSI SAR and Technical Specification references used to answer questions 1 and 2 above. Identify specific reference sections used for any,"Yes" answer.
q O Als109-Rev.-002 Page 19 of:86-Q r
e t-vb y s e P-+eu Tw=r
-*r-e erW.sa r
4 h
Plant Modification Mod. No.92-108 Installation Package Field Rov. llo.
2 Page No.
C12 PART 1: SAFirl'Y ANALYSIS DOCUMENT NO.._. PM 92108 REV.NO.
2 DESCRIPTION OF CilANGE:
This safety analysis has been prepared to discuss the changes to be implemented by Plant Mod 10 cation No. 92108.The necessity for the modification stems from the fact r
that single failure modes to the Control Building Emergency Air Filtration System (CBEAF) have been identined. One of the two single failure modes can be ellminated in a relatively short time frame. The other requires extensive modiacation to the chlorine detection logic.
EER 924352 has been pre [ared which demonstrates that although a single failure within the logic of the Cl3EAF does not meet the design criteria for the Control Building Heating, Ventihtlon, and A!r Conditioning System (CBHVAC) as stated in the UFSAR, the conseque...:es of that single failure will not result in a situation in which the NRC Acceptsnee Limit for radiological consequences to Control Room personnel could be exceeded.
The proposed resolution to the above stated problem is included in this two phase modification. Phase i requires modi 0 cation to the start logic of both trains of CBEAF.
Should it become apparent that Phase il modi 0 cations would not be complete until after startup, the relocation of the Chlorine detection system logic power to a UPS source would be iequired. His work would be required.to be complete prior to start-up of either unit. This tempo.rary UPS power source design is included in the Phase i package.
Phase 11 contains the permanent deslyn required to eliminate ihe Chlorine detection system single failure input to the EAF. De work to install this design will take place during the current forced outage (13108F9 & 11210F6) but could continue during power operation with NRC approval of a Request for Authorization to Operate (RAO) based on EER 924352. Details of the single failure modes and how the problem was identined follow.
m Plant Hodification Hod. No.92-108 Installation Packago Field Rnu. No.
2 Pago ho.
C13 PART 1: SAFLYrY ANALYSIS DOCUMENT NO.
PM 92108 REV.NO.
2 ANALYSIS (CONT.):
During investigation of an Operating Experience (OE) Report #5366 concerning
" preferred / standby" logic for 3tandby Gas trains, it was noted that the Control Building IIVAC Emergency Air Filtration (EAF) also utilized a " preferred / standby" logic connguration. As the Standby Gas Tmins do not use the " preferred / standby" logic there was no problem with the existing design (ref.: DilD 10 for SBGT design details). He logic for the CBEAF was also reviewed _ and it was revealed that previously unidentitled single failures could occur (ref.: ACR 92-642).
Other than normal ventilation and heating / cooling of the Control Building, the CBilVAC system must provide habitability during three different design basis events, ne first concerns a radiation event (Main Steam Line Break [MSLU) or Loss of Coolant Accident [LOCA]). The second event concerns the complete nipture of the 55 ton chlorine tank car located near the Service Water Building. The third is a smoke event.
in the MSLB or LOCA event the CBHVAC system is required to isolate and enter the recirculation mode on a Control Room Area or Control Room Intake High Radiation signal from the Area Radiation Monitoring System (ref.: CBilVAC System DDD 37, Section 1.3.1).
Upon receipt of a high radiation signal, the CBilVAC System is automatically realigned' to the emergency mode of operation. He fresh air inlets close isolating the control room. At the same time, the emergency air filtration unit begins operation, recirculating the control room air to minimize contaminated build-up in the occupied areas, ne.
system responds to a smoke event in the same manner it does for radiation.
In the event of a Chlorine release the CBHVAC goes into full recirculation mode, with -
no outdoor air intake (except for the battery rooms). The emergency filtration trains do not start since they do not remove chlorine and may be damaged by it (ref.: CBHVAC-System DBD-37, Section 1.3.2).
L
4 Plant Modification Mod. No.92-108 Installation Package Field Rev. No.
2 Page No.
C14 FART 1: SAFl?!Y ANALYSIS DOCUMENT NO.
PM 92-108 REV.NO.
2 ANALYSIS (CONT.):
no chlorine detection system is designed " fail safe" such that any failure (i.e. loss of power, detector failure, etc.) willisolate the control room in the same manner as a tnic chlorine signal, ne CBEAF system is designed to meet the single failure criteria as described in IEEE '2791971* (ref.: UFSAR Se: tion 9.4.1.3.c,Safetv Evaluation). He single active failure criterion referenced previously is satisfied except for 2L D-CB,2J D.
CB,2H D-CB, and SV-916 (ref.: NUS4697, Rev. 2, Fage A 11). Dese exceptions have been accepted by the NRC. In contradiction to the above requirement and accepted exceptions, the follewlag describes how the single failure criteria is not met.
As discussed above ACR 92-642 identifies the fact that upon loss of power in the control logic of the preferred CBEAF train, the standby train will not start automatically as intended. This is due to a lack of a start signal upon loss of power. By origlaal design the system uses a 10 second timer which is used to initiate a start signal to the studby train t,hould the preferred train fail to start. On a loss of power to the preferred train the 10 second timer is never energized and therefore an automatic start signal to the standby train is never sent. A plant test was initiated usinE an Al ll7 to verify system operation and demonstrate that although the-train would not automatically start, it could be manually started, ne fuse providing control power to the A Train of EAF was pulled. De next step required the B Traln to be started by placing the control switch to the 'ON" position. It was discovered that when the control power fuse was pulled that the control room HVAC isolated, in addition the B Train of CBEAF was unable to be started manuall),
it was determined that this was caused by the fact that the chlorine detection logic receives its power from the A Train CBEAF control logic. By pulling the fuse for the' A -
Train the control power to the chlorine system was lost which in turn falls the logic in the 'saie' position. The " safe" position for the chlorine system is to isolate control room HVAC and prevent or secure the operation of the CBEAF. This is done to prevent the intrusion of chlorine into the control room and CBEAF filter trains.
Plant Modification Mod. lio.92-108 Installation Package Field Rev. No.
2 Pago No.
C15 PART 1: SAFirlY ANALYSIS DOCUhtENT NO.
Phi 92108
._, REV. NO.
2 ANALYSIS (CONT.):
De actions which occur in the CHEAF system as a result of a chlorine system failure or chlorine accident are appropriate and in compliance with the requirement of Reg. Gulde 1.95 (Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release). The problem is that should a hialn Steam Line Break in the turbine building occur, concurrent with a chlorine system single failure, the control room ilVAC would Isolate as required but the CBEAF would not start (Isolated by the chlorine failure).
Given that the failures identitled can render the CBEAF inoperable duting a radiation.
event. a study to determine whether or not the calculated dose received by the control room operator would exceed the limits of GDC 19 was requested from UE&C (ref.:
CP&L Calc. No. OVA-004l).
The assumptions used in this study were that a htSLB had occurred. Concurrent with the htSLB a single failure prevents both trains of CBEAF from starting. The results show that the control room operator would receive approximately 96% of the allowed dose (30 rem thyrold) in alx hours. The dose continues to increase up to 29.5 rem in approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The dose then levels off at 29.5 rem for 30 days (duration of accident). The results of this analysis show that even without both trains of EAP the control room operator dose rates are within GDC !9 limits. Even though there is very little margin in the analysis the assumptions used are conservative.
Some of the conservatism included in the analysis is described here for understanding. It is assumed that for the design basis steam line break that a complete rupture of a main steam line break takes place in the turbine building. 140,000 lbs of steam and water is -
released which in turn falls the turbine building enclosure.
a
-Plant Modification Mod. No.92-108 Installation Packago Field Rev. No.
2 Pago No.
C16 PART 1: SAFirlY ANALYSIS DOCUhtENT NO.
Phi 92108 REV. NO.
2 ANALYSIS (CONT.):
A puff release is assumed which then envelopes the Control Duilding, in order to determine the duration of Control Dullding exposure to the plume a uniform spherical cloud which passes the Control Building at a conservative 1 meter per second wind velocity is assumed. To account for potential for non spherical shapes and possible reduced wind velocity a conservative factor of 10 times the exposure duration is applied.
An indication of the conservativeness of the factor of 10 is that if the plume were assumed to be not spherical, but turbine building shaped, and to somehow approach the Control Bullding enden;-and if the inferred (UFSAR Section 2.3.6) plant design basis ground level release wind velocity of 0.54 meter /see were used, the calculated increase in control room doses would be.less than one-third the result obtained using the factor of 10.
Another factor which adds conservatism to this analysis is the fact that the design basis main steam line break as defined in the UFSAR assumes a 10.5 second htSIV closure i
timc after the break. In actuality the technical specification required closure time is 2:3 to s5 seconda (Technical Specification 3/4,4.7).ne differences in the amount of steam 1
and water released with a 3 to 5 second htSIV closure time have not been calculated but can be assumed to be significantly less than that released in 10.5 second.. This would serve to reduce the size and activity of any release.
As in all habitability calculations for htSLD performed to date no credit has been taken ;
for atmospheric dilution. This is due to the fact that the turbine building puff release is in such close proximity to the control building intake plenum. All the above conservatism stpport the fact that doses received by the control room operations personnel would remain below GDC 19 limits. An Independent - review of the analytical -
methods and results obtained.by UE&C has been performed by NUS (ref.: CP&L Cale.
No. OVA 0042) which further confirms the validity of the study.
r-,,
-mm y-
1 Plant Hoditication Mod. No.92-108 Installation Package Fleid Rev. No.
2 Page No.
C17 f
PART 1: SAltlHY ANALYSIS DOCUMENT NO.
PM 92108 REV.NO.
2 ANALYSIS (CONT.):
In addition to the dose calculation, a Probability Risk Assessment (PRA) was also performed to determine the probabilities of a main steam line break concurrent with a loss of EAF function due to a Chlorine Detection System failure. He results of that review show that the probability would be 1.1 x 10 for a period of four months.
L Ilased on the data presented in EER 92 0352,it can be demonstrated that although the EAF system does not meet the single failure criteria of IEEE 279 1971 for a radiation event, the probability of a MSL11 concurrent with a failure which prevents the EAF i
from t. tarting is extremely unlikely. In addition, should this scenario take place it can be shown by analysis that the GDC 19 dose limits for control ronm perrnnnel will not be
- exceeded, ne safety analysis from EER 92-0352 was reviewed by the PNSC due to the reduced margin of safety as calculated in the UE&C dose calculation. He previous maximum calculated dose for any Design Basis Accident to the control room operator was 19 rem as stated in the final SE on control room habitability (NRC-89103). This EER demonstrates that the maximum dose expected in the control room following an MSLB would be 29.5 rem.
The conclusion reached in the EER and used by the RAO is that it is acceptable to allow power operation of either(both) unit (s) for a duration of four months '(basis for PRA Analysis) with the knowledge that this modification, Phase I will be installed and operable prior to start-up and Phase 11 will be installed within four months after _ startup.
As stated before NRC approval of the plan outlined in the EER is requ!*ed before implementation. A detailed description of the work to take place in each phase of the modification is provided.
l l~
l
Plant Hodification Mod. No.92-108 Installation Package Field Rev. No.
2 Page No.
C18 PART 1: SA1 lily ANAINSIS DOCUMENT No.
PM 92108 REV.NO.
2 ANALYSIS (CONT.):
PIIASE 1:
Phase I will be designed to permanently eliminate one of the two single failures. His phase will climinate the single failure associated with the start logic.To resolve this problern a simple change to the logic is required. De change involves reversing the timer logic so that the
- preferred train fall to start" relays 342A and 345A are de-energized on a fall-to-start signal. This will automatically place the stand by train in the
" preferred" mode up(m a loss of power to the preferred train or if the preferred train fails to start (the original design intent).
Should the Phase 11 modifications not be able to be completed prior to startup a temporary resolution to the Q/Non-Q separation issue would be required, The temporary resolution of the Q/Non-Q separation issue would involve relocating the power for the Chlorine detection logic from the Div.1/ Class A power it now receives to the uninterruptible Power System. As discussed the Chlorine Detection Logic is Non-Q and can therefore be fed by the Non-Q UPS. De relocation of the power off the CBEAF Train A logic also serves a dual purpose in that by removing the power from the Div. I feed a loss of Div. I power at that point (Train A logic) will not fall both trains of the EAF. This will not eliminate the possibility of a loss of UPS from falling both trains of EAF but reilability will be improved. He relocation of the Chlorine Detection Logic from Train A of EAP to the Non-Q UPS has been reviewed by the Electrical Analysis Group.
I
i Plant Hodification Mod. No.92-108 Installation Package Field Rov. No.
2 Page No.
C19 PART I: SAFIrrY ANALYSIS DOCUMENT NO.
PM 92108 REY. NO.
2 ANALYSIS (CONT.):
PHASE I (Conti As mentioned the installation work associated with Phase I will be accomplished prior to startup. Should it be required that Phase 11 InstaMation activilles extend beyond the startup of either unit, the temporary UPS power feed described almve would have to be performed. The ponion of the modification which contains the temporary UPS power is written with the option of performing the installation or not as dictated by such factors as; Phase 11 completion, unit stanup schedules, and NRC acceptance of RAO The end result of the Phase I changes (with the temporary UpS power feed) would be that the CBEAP would automatically start when required upon receipt of an isolation and initiation signal including the standby train if the preferred train falls to stad for whatever reason (failure, loss of power, etc). This would not eliminate the possibility of a CBEAP failure due to a single failure within the Chlorine Detection System which has been addressed in EER 92 03$2.
PHASE 11; The permanent resolut!on of the Chlorine Detection Logic single failure input to the CBEAF is to provide a logic design which will be able to take a single credible failure without disabling the protective function of the CBEAF. In order to provide this design a onemut of two-taken-twice logic will be utilized. 'Ihis will require the addition of 2 l
more detectors per sampling location which consist of the Control Building intake air l
plenum and the Service Water intake Building. This will bring the number of deectors utilized at each location from the present design of two to a total of four. As there are two sampling locations the number of detectors associated with the Chlorine Detection logic input to the CBEAF will be increased to eight.
l l
2
Plant Modification Hod. No.92-108 Installation Packago Field Rov. No.
2 Pago No.
C20 PART 1: SAFirl'Y ANALYSIS DOCUMENT NO._,. PM 92108
_ REV. NO.
2 ANAL.YSIS (CONT.):
1 PilASE II (Cont.h The four detectors per sampling location will be installed divisionallred such that two will be Division I and two will be Division 11. The logic will be designed such that two detectors per location will be required to sense chlorine in orfer to affect an isolation of the CBEAF. This willinsure that spurious detector isolation wl!l not isolate the CBEAF causing unnecessary 1.lcensing Event Reports (1.ER's), in additlen, by using the one-outmf two-taken-twice legle, a loss of one division of power to the detectors will not place the CBEAF in an isolated condition. This design concept will also eliminate any other single credible failure within the Chlorine D*ction logic from ir.olating the CBEAF.
In order tc prevent a loss of power on one division from isolating the CBE4F as a result of two chlorine detectors losing power, the chlorine detectors which now " fall safe" (isolate on loss of power) must be replaced with detectors which do not isolate on loss of power. A revision of the existing Chlorine Detector Specifica:lon 252-100 is planned as part of this mod 10 cation. The new detectors will be installed in approximately the same locations as the existing detectors and will be purchased and installed seismically qualified.
If required, the Phase I installation of a UPS power feed to the Chlorine Detection logic will be removed in Phase 11. As the Chlorine Detection logic will now be divisionalized the Div. I and Div.11 Chlorine Detection logic will be fed from Div. I and Div.11 of the CBEAF start logic respectively. This willinsure that a loss-of power on a complete division will still provide the protstive function from radiation and chlorine on-the other division. As isolation-is required netween Q and Non-Q logic, new fuses will be installed.between the Non-Q and Q portions of logic. These fuses will be coordinated with the upstream bteaker and analyzed to insure that a failure in the Non-Q portion of the logic will not adversely affect the Q portion. 'The Div. I and Div.11 power feeds to the CBEAF willbe analyzed to assess the impact of the additional / revised chlorine detection logic.
O
4 Plant Modification Mod. No.92-108 Installation Package Field Rev. No.
2 l
Page No.
C21
-i PART 1: SAFirl'Y ANALYSIS DOCUMENT NO.
PM 92108 REV. NO.
2 1
ANALYSIS (CONT.):
i PHASE 11 (Cont.h
'i The installation of the above mentioned system will require the use of several spare i
cables between the Cdatrol Bullding, Diesel Building, and Service Water Building. De cab:es will be terminated in their present location or pulled back to new termination
~
boxes installed specifically for this project. They will be connected to provide the necessary signal function to the CBEAF He use of spare cables is the only way to provide the necessary signal due to the fact that no raceway exists le which additions:
cables can be pulled. Atiempts have been made to pull new cables but no success has q
been had to present.
i ne installation also requires several new runs of conduit and associated supports in the.
Service Water Building and Control Building. Structural work also includes the' mounting -
of the eight _new Chlorine Detectors within the Control Building and Service Water Building. Stainless steel and coated materials will be utilized in the Service Water-Building structural edditions to provide resistance to corrosion due to the salt water environment present in that location.
=i ne detectors mounted 'in the CBilVAC. Mechanical' Equipment Roon and sensors -
located in the CBliVAC Intake plenum willbe installed such that they remain operable during and after the design basis earthquake, tornado, ~flaod, missiles, and other' natural phenomena, nis is to meet the intent of Regulator) Guide 't.95, -
The detector sensors located at the Chlorine. Loading Area will be seismically quallfled?
and installed in reinforced stainless steel enclosures, it is recognized'that the Chlorine-Loading area sensors will not be designed to withstand-the design basis tornado._This lsL::
~
acceptable due to the fact that any chlorine release resulting from tornadic-' action woulda be dispersed at a much greater rate than that assumed for a design basis chlorine release (see " Study'of Accidental Chlorine Release" dated _4/2n3) due to. extreme wind (_
conditions.
n
.b i.
1 Plant Hodification Mod. No.92-100 Installation Packago Field Rov. No.
2 Pago No.
C22 PART 1: SAFirrY ANALYSIS DOCUh1ENT NO.._._1%i.22108 REV. NO.
2 ANALYSIS (CONT.):
Pil ASE 11 (Cont.):
The sensors will be mounted approximately 28 feet apart to provide divisional separation. The sensors are mounted approximately 1 foot above ground elevation in order to insure that a chlorine release (heavier than air) would be detected. As a result of this, the sensors are protected from flooding to 21.0 ft mean sea level (MSL) Design basis t,till water flooding / surge for ilNP is 22.0 ft htSL. %e design basis flood would occur as a result of the Probable hiaximum ilurricane (PMil) coincident with the peak local astronomical tides. (ref.: UFSAR Sections 2.4.5, Probable hiaximum Surge and Sdche Floodirm and 1A, Eater Level (Flood) Deslen). As in the case of the tornado referenced above, the.<inds a aciated with the PMil would disperse any chlorine release at a much greater rate than that assumed for a design basis chlorine spill, in the unlikely event diat chlorine gas should reach the Control Ilullding Intake plenum during a tornado or hurricane, the subsystem in this location 'would isolate the control room to provide the necessary protective action. Based on the above, incapacitation of the Control Room Operator is prevented during the design basis natural phenomena with the potential to cause a chlorine release, ne new Chlcrine Detectors use an amperometric sensor consisting of a platinum cathode and silver anode joined by an electrolytic salt bride all enclosed in a permeable membrane. Dis design eliminates the majority of the maintenance now required on the existing detectors. %1s design wili also eliminate the majority of LCO's associated with the present " drip
- type detectors; The detectors selected for use have been in service at several other nuclear facilities and have proven reliable service.
J
Plant Modification Mod. No.92-108 Installation Packago Field Rev. No.
2 Page No.
C23 i
PART 1: SAlti?rY ANALYSIS DOCUMENT NO.
PM 92108 REV, NO.
2 ANALYSIS (CONT.):
PHASE II (Cont.h The cunent schedule provides for the installation of Phase 11 work outlined above during the current forced outage. As a contingency plan, a Request for Authorization to Operate (RAO) will be submitted to the NRC based on the conclusions of EER 92-0352,'The EER provides the justification for performing Phase 11 Installation work after startup The modifLdon will provide the necessary cautions and instructions to allow installation during the current outage and will require revision to add specific instruction to accommodate the operating conditions of the unit (s) at power operation.
The current schedule puts installation of the Phase !! equipment sometime after the first of the year, This would be beneficial from a chlorination standpoint as the demand for chlorination during the winter months is reduced. In conclusion,14 s changes as outlined above will eliminate the known single failures within the Control Building Emergency Air Filtration System, eliminate the separation problem, and provide a more reliable Chlorine Detection System.
- J
Plant Modification Mod. No.92-108 Installation Packago Field Rev. No.
2 Page No.
C24 PART 1: SAFirTY ANALYSIS DOCUMENT NO.
PM 92-108 REV. NO.
2
REFERENCES:
EER No. 92-0352 - CBEAF Single Failures DDD 37 Control Building ileating, Ventilating, and Air Conditioning System Reg. Guide 1.95 - Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release NRC 89103 - Safety Evaluation (SE) Regarding Control Room Radiological liabitability LER l 92-018 Failure of the CBEAF System to Meet Single Failure Criteria for -
Radiation and Fire Events NLS 85 311 - Control Room liabitability (NUS-4758 - Control Room Radiological Reanalysis attached)
CP&L Calc. No. OVA-0041 - UE&C Analysis ' Control Room-Doses Following a Main Steam Line Break CP&L Calc. No. OVA 4042 - NUS Design Verification of UE&C Calculation Set
- 9527 8-CB41 10CFR50, App. A, General Design Criteria 19 - Radiation Protection for Control P.oom Operators NUS 3697 Rev,2 - Control Room liabitability Evaluation Brunswick Steam Electric Plarit (NRC TMI Action Plan item lli.D.3.4)
NUREG 75/087 Rev.1 - Standard Review Plan UC-07582 - Study of Accidental Chlorine Release, 4/2/73 J
Plant Modification Mod. No.92-108 Installation Package Flold Rev. No.
2 Page No.
C25 PART IV: UNREVIEWED SAFirIY QUESTION Dirl'ERMINA*nON DOCUMENT NO.
PM 92-108 REY.NO.
2 RESPONSES TO:
QUESTION 1:
No. As discussed in the analysis the CBEAP System is provided to provide protection to the control room operators from a radiological event. Of the accidents discussed in Chapter 15 of the SAR the main steam line break is the most limiting. De acceptability of not meeting the single failure criteria of IEEE 279 1971 for the CBEAF syste n does not impact any system, structure or component associated with the initiation of a Main Steam Line Break (MSLil) accident and therefore the probability of occurrence of an accident analyzed in the UFSAR is not changed.
QUESTION 2:
No. He operability assessment provided in EER 92-0352 demonstrates that the consequences associated with a main steam line break do not exceed the 10CFR50, App. A, GDC-19 limits. Although the GDC 19 limits are not exceeded the parameter (dose to control room operators) would be closer to the NRC acceptance limit thus requiring FNSC review-of EER 924)352 and associated Unreviewed Safety Question Determination. This modification does not change or accept changes to the accident analysis included in Chapter 15.
QUESTION 3:
No. The CBEAF was designed to the single failure criteria of IEEE 279 1971. This modi 0 cation brings the system into compliance with the single failure criteria as required by lEEE 2791971. By providing the single failure design the rystem is able to provide the design basis protection for which it is installed.
QUESTION 4:
No. He consequences of malfunction of the CBEAF are specifically addressed in EER 92-0352. It has been demonstrated by analysis and verined that a failure of the CBEAF to initiate will not increase the-consequences of an equipment failure above the limits set.by GDC-19.
fj
~
Plant Modification Mod. 110 92-108 Installation Package Field Rev. No.
2 Page 110.
C26 PART IV: UNRIIVIEWED SAFl?IY QUETI'10N D1?rERMINATION DOCUMENT NO.
PM 92198 REV. NO.
2 RESPONSES TO:
QUESTION 5:
No. His analysis is written to address costing accident protection and does not affect the accident modes themselves. As this modification only addresses the capability of the CBEAP to perform its safety function during a design basis event, no new accidents are created.
QUESTION 6:
No. Part of the previously accepted design basis for the CBEAF is that it meet the single failure criteria of IEEE 279 1971 with exceptions. nls analysis shows that mod 10 cations performed by PM 92-108 will bring the CBEAF system into compliance with the original design bases of the system. By restoring the system to its original design requirements no new malfunctions of equipment important to safety are created.
QUESTION 7:
No. De bases given for the Control Room Emergency Filtration System (3/4.7.2)are that radiation exposures be lirnited to 5 rem or less whole body or its equivalent. His is consistent with the guidance provided in 10CFR50, App. A, GDC-19. As discussed, the operability assessment included in EER 92-0352 demonstrates that exposures will meet the bases for Technical Speci0 cation 3/4.7.2.The technical specl0 cation bases for Chlorine Detection Systems (3/4.3.5.5) states " Operability of the chlorine detection system ensures that an accidental chlorine release willbe detected promptly and the necessary protective actions willbe automatically initiated to provide protection for control room personnel."
He chlorine detection system will be modined by Phase 11 to this modincation to provide the same or better level of protection.
It should be noted that this modi 0 cation will revise the Chlorine Detection Technical Specincation 3/4.3.5.5to renect the new system connguration. For details on this change refer to the RCI 2.1 prepared for this licensing change.
Plant Modification Hod. No.92-108 Installation Packago Field Rev. No.
2 Pago No.
C26A PART IV: UNREVIEWED SAllilY QUES'110N DIITERMINAT10N DOCUMENT NO.
PM 92-108 REV.NO.
2
REFERENCES:
UFSAR Sections 5.4.4,5.4.5,6.4,9.4.1,15.6.3, and 15.6.4 Tech. Spec. Sections including bases 3/4 7.2,3/4.4.7 and 3/4 3.5.5 s
4 I
i 4
q m
r-y g,
e
-,--4
-n
,-n
~,
g-
.cn-:
, e