ML13324A919
| ML13324A919 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/08/1986 |
| From: | Medford M Southern California Edison Co |
| To: | Lear G Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8607100233 | |
| Download: ML13324A919 (8) | |
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 July 8, 1986 Director, Office of Nuclear Reactor Regulation Attention:
Mr. George 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 Review San Onofre Nuclear Generating Station Unit 1 During the past two weeks several telephone discussions have been held between NRC and SCE staff regarding the subject review as a follow-up to the meeting in Bethesda, MD on June 24, 1986 and our submittals of June 26 and 29, 1986. The purpose of this letter is to formally submit the information which was previously discussed. Each issue is discussed separately in the following paragraphs.
- 1.
The Control Room HVAC Unit was inspected on July 5, 1986. During removal of the V-bed charcoal adsorber, what appeared to be moisture was observed on the bottom of the duct housing which supports the V-bed adsorber. The moisture felt oily to the touch indicating it may have been DOP. The HEPA filter is new and appeared in good condition. Further inspection of the V-bed adsorber indicated that the charcoal trays were damp to the touch and also felt oily (possibly DOP).
The areas around the edges of the tray, especially the lower portions contained small amounts of surface moisture beaded in the area.
Since the inspection has determined that moisture can be present in the charcoal filters, the HVAC unit operating time will be increased from the present operating time of one hour per month. The increased operating time will be consistent with the recommendations of Regulatory Guide 1.52 (10 hrs.) to minimize the buildup of moisture.
- 2. A sample of the used charcoal which was removed in May 1986 and which had been in place for approximately one year was tested to determine the moisture content. The sample was exposed to air at 300C and 95%
relative humidity for 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />.
This exposure resulted in a 0.2% weight gain for the sample. The sample was therefore not saturated after one year in service 6607100233 860708 PDR ADOCK 05000206 P
PDR 9I
Mr. G.
July 8, 1986
- 3. In order to assure acceptable charcoal performance characteristics the charcoal beds will be periodically replaced and samples of the used charcoal will be tested. Testing will be performed in addition to that required by the existing technical specifications. A test to determine moisture content will be performed in accordance with ASTM D-2867-70.
Organic iodide removal efficiency will be determined in accordance with ASTM D-3803, Method A (1/8 second residence time).
Elemental Iodine removal efficiency will be determined in accordance with ASTM 0-3803, Method D (1/8 second residence time).
The additional testing will be conducted at 300C as required by ASTM.
The initial operating interval will be 3 months for charcoal replacement and testing. Based on the test results, the operating interval will be adjusted as appropriate.
- 4. The efforts to provide improved sealing of the control room have resulted in a higher pressure at the discharge of the HVAC emergency cleanup unit. The unit is therefore operating at a higher back pressure on its performance curve. Consequently the actual measured flow rate is 900 cfm
+ 10% instead of 1000 cfm + 10% as originally specified. The newly determined flow rate of 900 cfm + 10% is now defined as the design flow and has been used in the revised dose calculations.
- 5. The HVAC flow data which was originally provided to the NRC has been revised to correct for a minor error in the duct dimensions. The revised data is provided as Enclosure 1 (telecopied on 7/1/86).
- 6. The control room operator dose calculations assuming a 30% organic iodide removal efficiency were telecopied to the NRC on July 3, 1986.
These calculations have been revised to include simpler operator shift assignments without affecting the resultant dose and are provided as. In addition, a case was run using the same assumptions as provided in Enclosure 2 with the exception of the use of 0% organic iodide removal efficiency and 700 cfm unfiltered inleakage. The effect on the calculated dose to the operators was less than 1 REM.
- 7. In order to assure that the use of respirators and KI pills during an actual event is consistent with the assumption used in the dose assessment, SCE committed to provide specific training to the Emergency Coordinators to properly implement the revised EPIPS which were provided to the NRC in our submittal of June 29, 1986. The training consists of instruction in the identification of precursor events which would ultimately require the use of respirators and KI pills during accident conditions.
Mr. G.
July 8, 1986 If you have any questions, or desire additional information, please contact me.
Very truly yours, Enclosure cc:
J. B. Martin, NRC Region V, Regional Administrator R. Dudley, NRC/NRR San Onofre Unit 1 Project Manager F. R. Huey, NRC Senior Resident Inspector
ENCLOSURE 1 UNI1 1 CONTROL ROOM AND TECHNICAL SUPPORT CENTER HVAC FLOW DATA PC V Test Date 6/3011 Test Configuration Data Point Description Comaents A33 OSA ffL2 Fan Curve (1)
A33 OSA k70 Flow Hood (2.)
A33 OSA OrificeAP A31 Supply 0 0 Traverse by TSC Hallway A31 Supply 14f6 3 Traverse in CR outside Watch Engineers (WE) office WE Register (N)
-7 Flow Hood WE Register (S) 2-e0 Flow Hood Total A31 OSA Flow Hood A31 Return
'-f t Traverse on CR Register (E)
CcI/Q Traverse on CR Register (W)
Total A31 Return
() /.
Traverse in 4kv Room A-50 OSA (2
Traverse 6
A-50 Discharge 1
Hot wire velocity very unstable due to transition ducting and close proximity to discharge of fan.
A-51 Discharge Traverse A-51 Return O
Traverse A-51 OSA Flow Hood Comments:
A-33 fan RPM as measured on 6/28/8b is 1927 RPM.
0760K-2
UNI1 1 CONTROL ROOM AND TECHNICAL SUPPORT CENTER HVAC FLOW DATA o
Test Date 6
Test Configuration 4 Data Point Descriotion CFM Comments A33 OSA qf5-0 ran Curve (1)
A33 OSA B7o Flow Hood (.)
A33 0SA 9/6>
OrificeAP
('&P - 0.7 )
A31 Supply Traverse by TSC Hallway A31 Supply Traverse in CR outside Watch Engineers (WE) office WE Register (N) 0c9l)
Flow Hood WE Register (S) 37 0 Flow Hood Total A31 OSA
/
Flow Hood A31 Return 3727 Traverse on CR Register (E) 5021f Traverse on CR Register (W)
Total 37e(c A31 Return Traverse in 4kv Room A-50 OSA c)
Traverse A-50 Discharge l
Hot wire velocity very unstable due to transition ducting and close proximity to discharge of fan.
A-51 Discharge 6179Q Traverse A-51 Return 83 0 Traverse A-51 OSA 0
1
)
Flow Hood Coments:
A-33 fan RPM as measured on 6/28/86 is 1927 RPM.
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/
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CENTR HACWLOWDAJ UNI1 1 CONTROL ROOM AND TECHNICAL SUPPORT CENTER HVAC FLDW DATA 6/) IT Test Date
/ 3z f/
Test Configuration (
Data Point Description CFM Comments A33 OSA q570 Fan Curve (1)
A33 OSA
()
Flow Hood (2)
A33 0SA 17,0 OrificeAP
(,&p. 0.J15 )
A31 Supply ef/5" 7()
Traverse by TSC Hallway A31 Supply I/
Traverse in CR outside Watch Engineers (WE) office WE Register (N) 2P/O Flow Hood WE Register (5) 370 Flow Hood Total 90iiL A31 0SA 25-Flow Hood A31 Return Z851 Traverse on CR Register (E) 504( 9 Traverse on CR Register (W)
Total 79570 A31 Return g30S Traverse in 4kv Room A-50 0SA
/3Z0o Traverse 6
A-SO Discharge AfI Hot wire velocity very unstable due to transition ducting and close proximity to discharge of fan.
A-51 Discharge
'-7()
Traverse A-Si Return 2gSO c Traverse A-51 05A Flow Hood Comments:
A-33 fan RPM as measured on 6/28/86 is 1927 RPM.
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as
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pRESSURE INUCHES OF RIATER
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- (I) 4KV ROOM NJAC; A-101 52
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VEo3LATIONo A-32 (3)
FAN ROM FA.S; EF-..5 EF-.b. EF-.co EF8d
.45 TSC EX7.UST FA2; EF-9 S COWROL AREA MEN's ROOM EXHAUSTF: EFF.
REVISED OPERATOR DOSE ASSESSMENT The table below provides the results of additional dose calculations requested by the NRC.
Dose values were calculated with the use of iodine blocking pills and respirators. In addition, an alternate operator shift arrangement of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> was used.
Control Room Operator Thyroid Dose Using 30% Organic Efficiency Iodine Dose Calculation Case I Variables Filter Flow Rate 810 cfm Unfiltered in-leakage 800 cfm Filter Efficiencies 90/30/99 Shift Durations 12-hour shifts Other Provisions
- With KI pills and Respirators OPERATOR THYROID DOSE (REM)
Crew No.
Shift Assignments 1
= 26.3 2
2, 4 Only.................
= 27.7 3
3, 5, 7 Only..............
= 27.8 4
= 27.8 5
9.........................
= 19.3 6
20.......................
= 11.0 Operator dose would increase by a factor of 21 without the use of KI pills and respirators.
1, 41, 43, 52, 54, 59 only.
7 days on beginning with shift 6 on day 3, and two additional consecutive 2-day shifts.
7 days on and 2 days off repeating for accident 30-day duration.