ML19321B243
| ML19321B243 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 03/06/1978 |
| From: | Fee W, Switzer D CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Stello V Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19268C980 | List: |
| References | |
| TASK-03-12, TASK-3-12, TASK-RR NUDOCS 8007300331 | |
| Download: ML19321B243 (22) | |
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CONNECTICUT YANKEE AT O M IC POWER COMPANY k* )
BERLIN. C O N N E C TIC U T P.O BOX 270 H ARTFORD. CONNECTICUT 00101 203-686 6911 March 6, 1978 Docket No. 50-213 Director of Nuclear Reactor Regulation A t t.a.
Mr. V. Stello, Jr., Director Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C.
20555
References:
(1)
V. Stello, Jr., letter to D. C. Switzer dated December 23, 1977.
(2)
D. C. Switzer letter to V. Stello, Jr., dated February 15, 1978.
(3)
V. Stello, Jr., letter to D. C. Switzer dated December 1, 1977.
(4)
NRC Staff Meeting Summary dated January 18, 1978.
Gentlemen:
Haddam Neck Plant Environmental Qualification of Safety-Related Electrical Equipment In Reference (1), the NRC Staff discussed its plans to review the environmental qualifications of safety-related electrical equipment as the first topic of the Systematic Evaluation Plan (SEP); the conduct of the SEP huu been discussed pre-viously in Reference (3). To initiate the review, the NRC Staff requested CYAPCO to provide within 60 days certain information.
(Note that additional time was requested by CLJC0 in Reference (2)). Additional background and interpretation of the requested information was received from the NRC Staff at a January 5,1978 meeting (see Reference (4)) and during a site visit on January 19, 1978.
In response to the NRC Staff request and in accordance with 10CFR550.54(f), CYAPC0 hereby provides the attached information.
The Attachment summarizes the results of the evaluation conducted by CYAPCO and Northeast Utilities Service Company (NUSCO) to assess the level of environmer.tal qualification of safety-related electrical equipment at the Haddam Neck Plant.
This evaluation was performed in accordance with the requests made in Reference (1) and the additional background and interpretations discussed at the two meetings mentioned above.
Based on the results of the evaluation, it is the judgment of CYAPCO that electrical equipment at the Haddam Neck Plant would perform its safety function such that the plant could be safely shutdown following the analyzed events.
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- ( ) Thus, CYAPCO believes that there is reasonable assurance that continued opera-tion of the Haddam Neck Plant would not create undue risk to the health and safety of the public.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY D. C. Switzer President I
By.
-De W. F. Fee Vice President Attachment
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STATE OF CONNECTICUT )
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Berlin g
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t Then personally appeared before me W. F. Fee, who being duly sworn, did state that he is Vice President of The Connecticut Yankee Atomic Power Company, the Licensee herein, that he is authorized to execute and file the foregoing information in the name and on behalf of the Licensee herein and that the statements contained in said information are true and correct to the best of his knowledge and belief.
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b5dA Notary Public My Commission Expires March 31,199g
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i DOCKET NO. 50-213 4
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CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT i
ENVIRONMENTAL QUALIFICATION OF SAFE 1Y-RELATED 1
ELECTRICAL EQUIPMENT C
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In a December 23, 1977 letter (l), the NRC Staff requested that CYAPCO re-
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view the level of environmental qualification of safety-related electrical equipment bor'- inside and outside the containment at the Haddam Neck Plant.
In response to this request, CYAPCO, Northeast Utilities Service Company (NUSCO), and various other consultants conducted such a review. The results of the review are presented below.
EQUIPMENT OUTSIDE CONTAINMENT 3
In February, 1975(2), and in various supplements, CYAPCO submitted its revised plans for mitigating the consequences of High Energy Pipe Break (HEPB) outside containment. These revised plans, as described in a December,1974(3) f letter, were necessitated by material availability problems related to the im-plementation of the CYAPCO original proposal (4). The original proposal had al-ready been accepted by the NRC (AEC) Staff in March,1974(5).
In its Safety Evaluation. Report (SER), dated July ?4, 1977(6), the NRC Staff discussed the results of its review of the revisid CYAPCO proposal to provide necessary protection against HEPB. Therein, the NRC Staff concluded, in pertinent part, that the " proposed systems of barriers, restraints, and en-
. capsulation sleeves provide an acceptable basis for satisfying the applicable raquirements of NRC General Design Criteria No. 4..." [See Reference (7) for details on GDC No. 4].
CYAPCO bas, therefore, concluded that the ability of electrical equipment located outside containment to withstand the limiting environmental conditions has been assessed previously by CYAPCO and NRC Staff and found to be acceptable.
EQUIPMENT INSIDE CONTAINMENT b
With regaa d to safety-related electrical equipment inside containment, two l
events sere considered in the CYAPCO evaluation, since these could result in x
A-2 the most limiting environmental conditions; these events were the Main Steam-line Break (MSLB) and the Loss of Coolant Accident (LOCA), as described in
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Section 10.3.3 of the Facility Description and Safety Analysis Report (FDSA) and the analyses (8) performed pursuant to the Interim Policy Statement (IAC) of June, 1971, respectively.
MSLB For the MSLB, CYAPCO has reviewed electrical equipment located inside containment, which is necessary for safe shutdown, as described in Section 10.3.3 of the FDSA and in Section IV of Reference (2). This review has indicated that the equipment noted on Table A-1 would be necessary' for safe shutdown and could be subjected tc the environment created by a MSLB inside containment.
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The environmental conditions to which this equipment would be subjected have also been evaluated by CYAPCO.
This evaluation has concluded that the contain-ment pressure following a MSLB would be expected to be less than that following g postulated LOCA. Thus, the containment pressure following a LOCA would be the more limiting environmental condition and should be used to assess equipment qualification.
CYAPCO has also evaluated the average temperature conditions inside con-tair. ment following a postulated MSLB. Analyses performed for CYAPCO by Teledyne 4
Engineering Services has indicated that the peak average containment temrerature expected following a MSLB would be expected to be between 251.7*F and 267.3*F, as shown in Table A-2.
Regardless of the specific assumptions, this peak would only exist for short periods of time.
The duration of the peak has been con-firmed generically and also by "best estimate" analyses conducted by the NRC L
Staff.,It is, therefore, the judgment of CYAPCO that the temperature environ-ment postulated for a MSLB would not be more severe than that postulated for
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a LOCA since, (1) the peak temperatures for both events are approximately equal, and (2) the duration of the temperature peak during the MSLB is sig-nificantly less than that of the LOCA. Thus, the temperature profile postulated for a LOCA can be useo *.o bound the conditions expected for the MSLB, O
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A-4 LOCA For the postulated LOCA, CYAPCO has also reviewed equipment located inside containment which is necessary for safe shutdown. This review has in-dicated that the equipment noted on Table A-1 would be necessary to function and could be subjected to the environment created by the postulated LOCA. Also included with Table A-1 are the functions and service times for this equip-ment.
The environmental conditions to which this equipment would be subjected has also been evaluated by CYAPCO. The radiation environment used in assess-ing the qualification of this equipment is given in Table A-3.
As noted therein, these levels were determined based upon a realistic assessment of the radiological releases following a postulated LOCA superimposed on the projected radiation levels for the normal operating environment.
- he realistic assessment of radio-logical releases following a LOCA was based upon the guidance of NRC, Regulatory Guide 4.2; the assessment also considered dose variations due to location, time following LOCA, and whether or not the equipment was exposed to the containment environment.
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It is the dpinion of CYAPCO that these radiation levels are realistic for equipment environmental qualification based on the excellent performance of the stainless steel clad fuel at the Haddam Neck Plant and, also. the fact that the analyses presented in Reference (8) indicate that no fuel melt is expected during a LOCA for the Haddam Neck Plant.
With respect to submergence of electrical equipment, CYAPCO has previously L.
evaluated the potential for flooding of equipment inside containment following a postuJated LOCA(9)
The NRC Staff has accepted that evaluation and the recommended actions (10),
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A-5
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Humidity and chemical spray environments have also been considered in the CYAPCO evaluation. Specifically,100% relative humidity (R.H.) and 1.5% boric acid were eva'uated.
It should be emphasized, however, at the Haddam Neck Plant, the containment spray system is not expected to be used during a postulated LOCA for control of containment pressure and radiological releases.
In fact, no credit has been taken in either type of analysis for the mitigating effects of the spray.
CYAPCO has evaluated the containment pressure response following a postu-lated LOCA. This evaluation has considered the information obtained from analyses performed in connection with the original design of the Haddam Neck Plant and more recent qualitative and quantitative assessments based on review of generic analyses. It is the judgment of CYAPCO that the pressure in contain-(
ment following a LOCA would rise to a peak value of approximately 30 - 35 psig within the first ten seconds, remain at the peak value until approximately 1000 seconds into the transient, and then decay to its initial value within 100,000
, seconds.
In determining the containment temperature environment following a postu-lated LOCA, CYAPCO utilized the pressure transient to the extent that, by assuming saturated conditions, the upper bound on temperature is reasonably established.
In addition, an engineering assessment of the peak containment temperature was made by pepresentative calculations and by reviewing generic analyses.
The re-sult of the overall effort was the confirmation that the containment temperature could be reasonably expected to reach an approximate peak value of 260*F in about the same time as the pressure peak. The temperature profile would follow the pressure profile up to the time of the peak pressure, after which time the rate of decrease in the temperature profile would lag behind the decrease in pressure.
A-6 CONCLUSIONS Electrical equipment which has been deemed necessary by CYAPCO to perform a safety function during the MSLB or 1DCA is listed in Table A-1.
Only that equipment,.which is:
(1) necessary for safe shutdown, and (2) exposed to LOCA enviornment, has.been included in Table A-1.
The CYAPCO evaluation has not ident!.fied any non-safety systems which could affect the safety function of equipment listed in Table A-1.
The limiting environmental conditions inside containment have also been evaluated and are described on Page A-1 through A-5 and Table A-3.
These condi-tions are felt to be realistic, yet still have some' inherer.t conservatisms in their derivation. The limiting environmental conditions have been determined i
based primarily upon consideration of the MSLB and LOCA environments; that is, j
normal operation has not been a significant contributor to the limits.
CYAPCO believes that this is a realistic approach since the normal operating environment would affect electrical equipment in a gradual process. Therefore, any deteriora-tion would be detected early as part of the extensive periodic surveillance, con-ducted' in accordance with routine plant operating and maintenance procedures and Technical Specifications,and, appropriate corrective action taken. Review of plant operations at the Haddam Neck Plant tends to indicate a relatively small
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number of equipment failures in over ten years of commercial operation.
Finally, CYAPCO has assessed the level of environmental qualification for the indicated electrical equipment by either test and/or analysis. For primary safety-related equipment, these tests and/or analyses have indicated that the electrical equipment at the Haddam Neck Plant is qualified to perform its particular safety h
function under the environmental conditions which exist during the time period l-requireil.to operate. Evaluation of the qualification in a radiation environment
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for some equipment is continuing, as CYAPCO has not yet been able to obtain the release of data from the particular vendor (s). Even in these cases, the specific equipment is not taken credit for in the accident analyses. For those evalua-tions which have been finalized, documentation of the qualification test and/or analysis is on file at the NUSCO Engineering Offices.
In conclusion, based on the results of the evaluation, CYAPCO believes that necessary electrical equipment inside containment would perform t
its safety function under the postulated limiting environmental conditions for the events analyzed.
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e. e e TA312 A-1 StBetAIT OF QCALIFICATIONS OF ELECTEIC (T) - Test Method of SWIPMDrf SUEJECTED TO toCA ENT130mmr
(>aalification EADDAN WECE PIANT MatIDITT/
0 0
0 G IMICAL B
LT!!!TT3C C
LIN' TING E
LDQTING E
SPRAT C
FIANT PEESSL'RE TEW 13ATURE U
RADIATION ENVIROBBer!
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EQUIP. 30 BQU1FMENT TITLE 1D:ATION INTIE000GNT ENYimatoGMT ENTIRDIDGNT
- ect $41 A.D anacter Coolaat-tmop saiddle tavel See Page A-5 YES See Page A-5 TES See Table A-3 YEM 100E/1.51 YES tsjection valves outer Annulus (T)
(T)
(A)
Boric Acid (T) im Domin. 5 0 Containmens 2
809 311 seactor Coolant Pump stiddle tavel TBS TES TIS TES Seal Water Satura Outer Amaulus (T)
(T)
(A)
(T)
Line Telve Contairment
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tev 312 teactor coolant Pump Middle Level TES TES TES TES j
Seal Water Return h ter Amaulus (T)
(T)
(A)
(T)
Line Talve containment C T 313 seactor Coolmat Pump hiddle Level TES TES TES TES Seal Water Retura oster Annulus (T)
(T)
(A)
(T)
Line Talve Containment IIDT 314 teacter Coolant Pump atLtdie tavel YES
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TEJ TES TES -
Seal Water Satura Outer Amaulus (T)
(T)
(A)
(T)
Line Talve Con taimensat
- a f $71A teactor Core Doinge anactor Cavity TES TES TES TES l
l Talve Coateiament (T)
(T)
(A)
(T)
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Ef4 7 4715 asactor Core Deluge tasctor Cavity TES TES TES TES valve Contatament (T)
(T)
(A)
(T) rev 23 seactor Containnsat tower lavel TES TES NOTE 1 YES Spray valve Outer Amaulus (T)
(T)
(T) l Coataimmeat wv 34 teactor containment tower level TES TES WOTE 2 YES Spray salve Outer Amaulus (T)
(T)
(T)
Come=ia==at 1
4 25-29 Charcoal Filter Sprey tower tavel TES TES
.10TE 3 TES Line valves Outer Amaulus (T)
(T)
(T) l Containment sect 2923 Charging Flow Stop Immer level TBS TES TRS TES I
Talve Outer Aamulue (T)
(T)
(T)
(T) j Containment 8907 292C Charging Flow Stop tower level TES TES TES TBS Valve Outer Aamulus (T)
(T)
(T)
(T)
Conta*n==at
- 907 780 Emit tahoard stop-atiddle Inval YES TES TES TIS l
tmop #1 valve outer Aamulus
- (T)
(T)
- (A)
(T) g Containment epov 7s1 aER outboard Stop,
tower tavel YES TES TES TIS Loop #1 Talve Outer Annulus (T)
(T)
(A)
(T) l Contatament 8 07 803 EER Outboard Stop-
- .swer Level TIS TES TBS TES 1
toop #2 Valve Outer Annulus (T)
(T)
(A)
(T)
Containment i
8307 $04 EHR Imboard Stor-Middle tavel YES TIS TES TES j
tmop #2 Telem Outer Amaulus (T)
(T)
(A)
(T)
Contaimmant get 200 latdown teolation Itiddle tavel TES YES TES
. TES Walve Outer Amaulue
' (T)
(T)
(A)
(T)
Containment j
F-17-1.2.3.4 Contaiammet Air to-Beiddle tavel YES TIS TES i
circulation Fa3 Outer Annulus (T)/(A)
(T)tys/(A)
(T)/(A)
(T)/(A) absters Containment
,'8FT C1-1.2.3 Preseurter Freasure Emmer letal 30TE 4 BDTE 4 uptt 4 BDTE Treammittere Outer Aa==dus Contaiammet g
1-1.2.3 Pressurier 149e1 taver level II soTE 5 if smE $
I 3DTE 5 y t Tr====tttere Outer Aamulua Coe ta i==== t
- Used gent ta =11 break taCA (where discharge rate la less thea charging rate for a prelmaged period of tian) and mais ot*ee AL%s break ta contatsmemmt for moraal caotAous of BCS to 200*F.
Wnst *e.W A 1DCA and Itain Staes Line Break.
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WY130tMDrf 3 FLAltT FWS$URE TEl@ERATURE 3
BADIATION a
e 0C17. 30.BQCTFMDrf TITLE IOCATION ENTIBotNNT ENT130lMENT n
IIIVIRONMENT EIPOSURE B
cr er cr
.I 1000V Control Cable All Arena See Page A-5 TES See Pese A-5 rote 6 See Table A-3 YES 100E/1.51 TES Centat===st (A)
(A) Deric acid (A) 6007 Power Cable All Areae TES TES TES TES Costaimment (A)
(A)
(A)
(A) lastnames Cable All Areas TES IIOTE 7 TES TES Contaiment (A)
(A)
(A)
Mineral 1meulated All Areas TES TES TES TES Cable Containment (A)
(A)
(A)
(A)
Silicon insulated Middle /lmwer level TES TES TES TES sypalon Jacksted Outer Annulus (A)
(A)
(A)
(A)
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'w Cable Cantainment Charcoal Filter kiddle invel TES TES 90TE 8 YES Temp. Detectors (40) hter Aamulus
-(A)
(T)
(A)
Containment
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Air Solenoids for Middle Imvel EIOrt 9 30TE 9 30TE 9 30TE 9
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car Fan Dampers (8)
Outer Ana.alus Containment TES W. -
Terminal Blocka lower Intel TES TES TES Outer Annulus (A)
(A)
(A)
(A)
'contatament 30TE 10 30TE 10 30TE 10 DOTE 10
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ee -
Containment Elee-lower Imvel
-h TES 9
TES
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- ts y
TES k'
trical Penetrations Outer Annulus (A)
(A)
(A)
(A)
Containment 30ft 11 30TE 11 IICTE 11 310rt 11 l
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Equipment No.
Function in Accident MOV 861 A-D Open to pemit safety injection flow to primary loops
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M0V 311, 312, 313, 314 Closes to prevent high temperature reactor coolant from flowing through the pressure housing of the RCS pumps MOV 871 A, B Open to pemit safety injection flow directly
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into the core and recirculation flow during long-term cooling 4
M0V 23, 34 Used as backup to reduce fission pro' duct concen-tration and containment pressure following LOCA MOV 25-29 Used as backup for fire protection of charcoal filters f
MOV 292 B, C provides charging flow for core cooling and recirculation flow during long-term :::olir.g Open to permit RHR flow to allow cooldown of~
MOV 780, 781, 803, 804 reactor coolant system-to less than 200*F
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following a small LOCA.
MOV 200 Containment isolation of letdown line F-17-1, 2, 3, 4 Used to effect a rapid depressurization of the containment and to provide for iodine filtration as fission products are released from the core PT 401-1, 2, 3 Initiate safety injection LT 401-1, 2, 3 1000 V Contro1~
Provides electrical power, control, and sig-600 V Power, and nals to safety related equipment Instrument Cabling Mineral Insulated Cable Provides electrical power and control to MOV 25-29 and charcoal filter temp. detectors Silicon Insulated, Provides electrical power to containment air Hypalon Jacketed Cable recirculation fan motors Charcoal Filter Detects high temperature in charcoal filter Temp. Detectors banks
s 2-(j Equipment No.(Cont'd.)
Function in Accident (Cont'd.)
Air Solenoids for CAR Shuts air off to actuators which open Fan Dampers containment air recirculating fan face dampers and close fan face bypass dampers Terminal Blocks Provide electrical connections to the individual circuits which utilize the blocks Electrical Penetrations Provide electrical connections for the individual circuits which utilize the penetrations e
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(i Service Times of Equipment Inside of Containment Required for LOCA (A) - Automatic (M) - Manual Time of Equipment Service-(From Start of Accident)
Equipment _
T.= 0 sec 3
Air Solenoids for 1 sec (A)
CAR Fans Dampers LT-401-1,2,3 2.5 sec (A)
PT-401-1,2,3 2.5 sec (A)
Within 30 sec (A) j MOV 861 A-D i
Within 30 sec (A) i M0V 871 A, B MOV 311, 312, 313, 314 Within 30 sec (A)
M0V 200 Within 30 sec (A)
MOV 292 B, C Within 30 sec (A)
F-17-2, 3
? days (A or M) f MOV 23,.34 Variable (M)
F-17-1 and/or -4 30 days (A or M)
M0V 25-29 Variable (M) f
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Charcoal filter Temp. Detectors Variable (A)
FOOTNOTES TO TABLE A-1 Note 1:
The evaluation of the level of radiation qualification of this equipment is still in progress in that CYAPCO is currently nego-tiating obtaining data from the equipment vendor.
It should be
.noted, however, that this equipment is not expected to be used during a postulated LOCA.
Note 2:
See Note 1.
Note 3:
See Note 1.
Note 4:
CYAPCO understands that tests performed at Franklin Research Labora- -
tory on pressure and differential pressure transmitters similar to PT401 and LT401 pressure have indicated the capability to operate (with error) at pressures and temperatures up to 60 psig and 294'F, respectivcif. This, in conjunction with the fact that within 2.5 t
seconds from the start of the LOCA, the transmitters will have per-formed their safety function by generating a signal to initiate safety injection, leads CYAPCO to conclude that the transmitter performance will not be adversely affected by the LOCA environment in the time they are required to function. However, our investiga-tion is continuing into the degree of error which these transmitters exhibited during these tests and its potential effect on the sur-veillance capabilities of the transmitters subsequent to the MSLB
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inside containment.
Should the results indicate the need to do so, the transmitters would be replaced.
Note 5:
See Note 4.
Note 6:
The manufacturer has demonstrated from the test results the capa-bility of the cable to perform satisfactory at 260*F for 45 minutes.
Control cable is utilized on the following equipments-MOV 861 A-D MOV 200 CAR Fan Air MOV 781 A, B MOV 292 B, C Solenoids i
MOV.311, 312, 313, 314 HOV 23, 34 All of the above equi;, ment, with the exception of MOV 23 and 34 (for which the accident analyses do not take credit), will have completed its safety function within 30.0 seconds after the start of the LOCA. Based on our engineering judgment, CYAPCO believes the cable would be able to perform its safety function since en-vironmental conditions would not be as severe as the test condi-j tions and, thus, would not limit the performance of the above equipment during the time of its required operation.
Note 7:
Instrument cable is utilized on the pressurizer pressure and Icvel transmitters. The cable material is similar to the 1000 V control cable. From analyses, it is concluded that the cable performance
( l will not be adversely affected by the accident temperature environ-L ment within the first few seconds of the accident, i.e.,
for the time in which the transmitters are required to function.
C.
Note 8:
This equipment has been qualified for a radiation environment of approximately 3.4 x 10" rads, i.e., the environment to be expected about one hour following a LOCA. However, this equip-ment is not necessary for safe shutdown; further, as described in Section 3.6.3 of the FDSA, it is not expected to be used following a LOCA.
Note 9:
The air solenoids will have completed their safety function about one second following a LOCA. From our analysis, it has been con.
cluded that this equipment would not be adversely affected by the LOCA environment for the time in which it is required to function.
Furthermore, these solenoids are fail-safe. #
Note 10:
A detailed evaluation of the environmental qualification of terminal blocks at the Haddam Neck Plant can be found in References (11),
(12), (13), and (14).
Note 11:
A detailed evaluation of the environmental qualification of con-tainment electrical penetrations can be found in Reference (15).
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