ML13324A905
| ML13324A905 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/26/1986 |
| From: | Medford M Southern California Edison Co |
| To: | Lear G Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8606300290 | |
| Download: ML13324A905 (11) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M. 0. MEDFORD TELEPHONE MANAGER, NUCLEAR LICENSING (818) 302-1749 June 26, 1986 Director, Office of Nuclear Reactor Regulation Attention:
G. E. Lear, Director PWR Project Directorate No. 1 U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Control Room HVAC Design San Onofre Nuclear Generating Station Unit 1 During a June 24, 1986 meeting with the NRC staff, additional information regarding the control room HVAC at San Onofre Unit 1 (SONGS-1) was requested. This information was to be supplied in a letter on June 27, 1986.
However, in order to better facilitate the staff's return to service review of the subject system, the early transmittal of the following information is provided as an enclosure to this letter:
- 1. A listing of the repairs to date on the control room HVAC system, the TSC HVAC system and the control room pressure boundary.
- 2. A listing of the most recent control room/TSC HVAC testing results.
- 3. A post-accident control room operator thyroid dose assessment, considering a 250 cfm unfiltered in-leakage value and both, with and without, KI pill and respirator credit.
8606300290 860626 PDR ADOCK 05000206 P
Mr. G.
June 26, 1986
- 4. A position regarding the proper source term for use in the dose calculations.
If you have any questions, please let me know.
Very truly yours, Enclosure cc:
- 3. B. Martin, NRC Region V, Regional Administrator R. Dudley, NRC/NRR San Onofre Unit 1 Project Manager F. R. Huey, NRC Senior Resident Inspector, Units 1, 2 and 3
ENCLOSURE 1 of 9 UNIT I CONTROL ROOM SEALING AND MODIFICATIONS
- 1. Blocked off control room air to Inst, Repair Lab (FCN and PFC required).
- 2. Blocked off the exhaust fan (EF-9) discharge for the kitchen (FCN required).
- 3. Repaired loose patch in the return duct in the 4KV room.
- 4. Repaired the hole in the side of A31 where the cooling coil lines petiaLratu.
- 5. Cleaned the lower drain pan and coated it in A31 (NCR-SO1-P-5821).
- 6. Replaced upper drain pan in A31 (NCR SO-P-5821).
- 7. Sealed the gap in the lower fan housing in A31 (I'x 84') (NCR Sol-P-5853).
- 8. Caulked duct seams with *Lock Bond" duct sealer and taped seams with "ARABOLI adhesive #60-89-05 and canvas tape. This was done on supply ducting outside the Control Room and on all return ducting including the A31 fan housing (FCN required).
- 9. Replaced the flex joint (asbestos) on the A31 return and supply with non-asbestos material (NCR SOl-P-5823).
- 10. Installed access panel in A31 suction plenum to allow flex joint replacement and a suction point for the test fan for the Inleakage test (FCN required).
- 11. Blanked the abandoned TSC return duct where it attaches to the A31 suction plenum (blank was installed on the inside).
- 12. Sealed all seams in 12"x12" supply duct that penetrates the TSC/CR boundary then returns to NOA's office (Duct sealer and "ARAB0L" used).
- 13. Brush type door seals added to the two control room boundary doors (FCN required),
- 14. Balanced 4KV Room HVAC flow to produce a positive pressure in the 4KV room of approximately 0.1" water gage with respect to outside atmosphere.
- 16. Verified sealed/sealed all conduit penetrations through the boundary walls.
- 17. Bisco sealed the two cable trays that penetrate the CR/TSC wall.
2 of 9 Unit 1 Control Room Sealing and Modifications Page two
- 19. Installed a fill connection on the loop seal drain for A51.
- 21. Installed a seal around shaft on A50.
- 22. Installed additional test ports on the ASO inlet duct, A50 supply duct and A31 return duct to support flow measurements.
- 23. Inspected and internally sealed all wall outlets, switches, ect. that are attached to or flush mounted to a boundary wall.
- 24. Non-concrete or non-block boundary walls. These walls include NOA's office, TSC/CR wall by viewing windows and north and east walls of shift supervisor's office. These walls are a plaster/wallboard combination sandwiched around 1/20 plate steel.
The wallboard/plaster generally only extends slightly above the false ceiling. The following methods were utilized:
- a. Steel plates had the seams and bolts caulked.
- b. Gaps between the wallboard/plaster and plate above the false ceiling were sealed with plaster and then caulked after plaster dried.
- c. Holes in the plaster repaired.
- d. Plaster to floor interface was sealed by removing baseboard, caulking and reinstalling the baseboard.
- e. Wherever physically possible, both sides of the boundary wall were sealed.
Installation includes the required fire damper (FCN's and PFC required).
0754K-2
3 of 9 ATTACHMENT B 25198 17
'H CHP PRE A-50 IA I
14 05A TSC EQUIPMENT ROOM 13 2519A TSC CORRIDOR REST-FC 2410 3
ROOM TECH SUPPORT CENTER EF-6 C 241 CAS (WATCH INSTRUMENT ENGINEERgs REPAIR SHOP CHEM OFFICE)
LAB 4
NOA 174 p
OFFICE H
R AP
- 410 CONTROL ROOM PRESSURETDATACPOINT 740BH PRESSURE PRE OIT
PRESSURE INGS OF WATnR Of SYSTEM LINE-UP AF ON OFF A*St.
Ae3U A.*t IMMB1,AA*S
.i
,o8ow
.Y/
Jo.31 32NE ON OFF A--.
AmSTi Aoss AoSt Ib oE Asm.
7S 20 3
20 t
lmoo o.
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Aa2
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- 1.
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ON OFF Aell AcES
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- 4.
I
.O ON OFF Weas ar.
.2'f 14 237 2,1
.12
-1.3 Z.07'i ON OFF A*$
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Ere 06 6
soWs.
A AAA AA A(1) 4 0as V aw A-101 (aRm 8LG VIO A-2L 3.Z75 (3
PAN ROOM FN:E-a FaE-C E
(aC EAU FAN; EF4 3
(
ROA AREA ENs NOTES:
(1) 4KV POOR KVAC; A-101 LIF~ 7/I'-A (2ADMI[N.
BLDG. VENILATION: A-32D/Tq7KV
,z (3FAN ROOM FARS; EF-8a* EF-8b. EI-8c, EF8d (s) CONTROL AREA MEms ROOM EXHAUST; EF-6.
5 of 9 PRESSURE - INA OF WATER SYSTEMoi LINE-UP o
E ON OFF Aot. Aest AUs*
KV MDM AmS3 VAN nes gre ON OFF AmaE A*s3 AoeS Aloom A..
.20.L.
.32
.32 0eo e e;
N1=64 EP AN W9.DIB Cyr8"I ON OFF AwSI, AI$S Ass 4KV to As$&
ADM IN U.LD Cire Ero..
EVe4.
PAN "xo"g ON OFF Ail A 19e AN Roo 3Y
.1S327Z j
iti' "Ec.e 26
.334.1.3 02 o1.f ON OFFR.-3 a
Amas Crop
=DIN IRAa I Mr.
41V 0M4 rAN 113 ON OFF A*SI A-s Eros 15.39 ON OFF-Amat AoSi E
awdE "co P.M4 MOON AM I
NOTES:
A A I1 4KV ROOMt HYAC; A-101 01 1
F v 6138 ADMIN. BLDG.
VENILATJON: A-32 FAN ROOM FANS; EF-8a, EF-8b.
EF-8c. EF8d 4
TSC EXHAUST FAN; EF-9 (S CONTOL AREA MEN's ROOM EXHAUST; EF-6.
ATTACHMENT C 2519B 1
C H P A-51 E H E R OSA P
A-E PRE A-50 AlR R
2519A 8
?
TSC CORRIDOR REST-
,--FC 2410 TECH SUPPORT CENTER u
FC 2411 CAST (WATCH INSTRUMENT ENGINEER'S REPAIR SHOP CHEM OFFICE)
LAB 0RI FI CE-,-A A-33 NOA 1740A P
OFFICE H E R A E
A-31 2
CONTROL ROOM 2
-c
-F-------
OSA 17408 4KV ROOM FLOW DATA POINTS
7 of 9 FLOW RATES - CFM (I)
(2
- SYSTE14,
-~m LINE-UP Linr ON OFF Augl Aust A-D*
4KV AG..
A*S AmAIN ELbe tv.*
PM4 agg-g EP*
ON OFF AoSI, A&32 Asia 01 IWO$
-w:
I-O ON
-OFF AeSi A*S2 Am-t AeoV VAN noM A-81 is AHI mas wr**4 ON OFF A
s A21 R
- AWasN g.D0 Eae4 4aV mo=s VAN Nec ON OFF LSSI 09 AW90 N
A.s1 eI ar*o 4KV Fe
'4S)1 AN PO.CH0 C
ON OFF Ae@1 Aete We**
AoS Ae30 We*
4KV SUlam VAN FMDON AMlIN mLi NOTES:
pn7 TA6l
-/25 (1) 4KV ROOM MVAC; A-101 (2ADMIN. BLDG, VENILATION: A-32 (2)SupyFo lcatdb 3
FAN ROOM FANS; EF-8a, EF-8b, EF-8c, EF8d (4)
TSC EXHAUST FAN; EF-9 f
1NDE)
EU 1dt (5)OTR L AREA ROOM EXHAUS:
() Traverse taken downstream (1) KV ROM HAC; -IO1orifice plate.
(3) AN OOM ANS EF-a, F-8b EF8c, F~d(2)
Supply Flow calculated by TSC XHAUT FN; E..9adding flos of travere (4) j ~aei. ~inside CR and the two wate (5) CONTROL AREA MEN's ROOM EXHAUST; EF-6.
egne eitrfos
8 of 9 Table I provides the results of edditional dose calcatioons requeted by the NRC.
Allowances were made in these calculations for reduced organic iodine efficiency in accordance with NRC meting agrements.
In addition, an alternate operator shift arrangement of 12 houra vas used.
Dose vaines were calculated with the use of todine blocking pills and respirators, and asaumed two values of unfiltered in-leakage.
TABL I
Control Roa Operator Thyroid Dose Using 65% Organic Efficiency Iodine Dose Calculation Variables Case I Case II Filter Flow rate 1100 ced 1100 fa Unfiltered in-leakage
- 300 eta 900 eft Filter Efficiencies 95%/65/99 95/65/99 Shift Durations 12-bour shifts 12-hour shifts Other With KI pills &
With X2 pills &
Provisions Respiracors Rspirators OFIRATOR THIROID DOSE (Rl)
Shift Crew So.
Assignments 1
1, 4 only
- 18
- 29 2
2, 5, 8 Only
- 19
- 29 3
3, 6, 9 Only
- 12
- 18 4
7.
m 13 a 20 5
11.....*.
9 15 6
2 2 6
10
- Operator dose vold increase by a factor of 21 without the use of KI pills and respirators.
- Regular shift schedule - 7 days on, 2 days off for accident 30-day duratiou.
- Thia was originally stared to be 250 chf.
300 a was used for leak rate test margin.
- S~t~Jt tS~t~-st tS~t
- $'t
- t t; ';S
$::t3
- $ :%, :5:t.5 Wk
- 55 W
5
- 554 W3
,:'~:$ :%4 535:
k
- %: SA :r':t: : :s$s:r*:%'
3
- 5%:5:5.5:5fl:5 -5 :S:,fl kx 5:1:
": 4.54i*
N vkw!3 M 5*:ts M.:1 :
W 5i 3Vj551.fxs55 vawn 3
9 of 9 SOURCE TERM The source term currently used by the NRC staff to calculate the post-accident operator doses is based upon a 14.5 to 30 day purge for hydrogen control.
This was based upon analysis done in 1977 to support the issuance of Amendment No. 25 to Provisional Operating License No. DPR-13.
Since that time, in response to NUREG-0578 requirements, during the refueling/steam generator repair outage that ended on June 17, 1981, SCE installed hydrogen recombiners in the SONGS-1 containment for post-accident hydrogen control.
Therefore, the containment purge assumption is no longer appropriate.
The following iodine concentrations should be used in any dose calculations:
ISOTOPE 0-8 HR 8-24 HR 24-96 HR 96-720 HR 1-131 3.55E-11 2.04E-11 1.10E-11 1.15E-12 1-132 2.10E-ll 5.28E-13 3.90E-16
-0 1-133 5.95E-11 2.39E-11 4.36E-12 1.53E-14 1-134 1.73E-11 6.36E-15
-0 1-135 4.58E-11 8.17E-12 2.64E-13