ML19347C742
| ML19347C742 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 12/30/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19347C743 | List: |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-3.D.3.4, TASK-TM 1013, NUDOCS 8101050352 | |
| Download: ML19347C742 (12) | |
Text
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,e vlRGINI A E E CT RIC AND PO* E R COMP ANY, RICHMON D. VIRGINt A 23261 December 30, 1980 Mr. Harold R. Denton, Director Serial No. 1013 Office of Nuclear Reactor Regulation PSE&C/LTW: wang /vm1 Atto:
Mr. Darrell G. Eisenhut, Director Division of Licensing Docket Nos. 50-339 U. S. Nuclear Regulatory Conmission 50-339 Washington, D.C.
20555 License Nos. PF-4 IFF-7
Dear Mr. Denton:
Enclosed is our response to Iten III.D.3.4 of TUREG-0737 for t' orth Anna Power Station.
Much of this information has been previously submitted for North Ann 5 Unit 2 licensing.
(See letters to Mr. Denten, Ser191 No. 155 dated February 25, 1980, Serial No.155A dated March 17, 1980, and Serial No. 509 catec July 7, 1980). to this letter contains the information that was recuested in your Attachment 1 to Item III.D.3.4 of NUREG-0737 contains the results of the analysis of control room concentrations fron postulated accidental release of toxic gases.
These results were incluced as Table 1 with our Letter Sarial No.155A dated March 17, 1980.
Those design basis accicents which could result in some radiation release to the environs have been evaluated to determine control room operator exoosures.
These exposures are limited to 2.5 REM whole body dose and 10 ret >
tnyroio dose, as cocumented in Sections 6.4 and 12.1 of the FSAR.
Based on these reviews of control room hat:itability for North Anna Power
- Station, we conclude that the control room meets the requirements of Regulatory Guices 1.76 and 1.95 and Standard Review Plan Sections 2.2.1-2.2.2 ano 2.2.3.
Additionally the control room meets the requirements of Standard Review Plan 6.4 except as follows:
a)
The emergency ventilation system is designed to develop a positive pressure of.05 inch water guage differential pressure ratner than 1/8 inch water gauge as stated in the Standard Review Plan.
This satisfies the intent of the Standard Review Plan by oemonstrating a ?n '~tive pressure within the control room.
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Emergency supplies (i.e:
food and water) may not be wholly contained within the control room complex but are available nearby.
This is felt to be adequate since limited traffic in and out of the control room is possible while the control room is isolated.
These minor exceptions to Standard Review Plan 6.4 are felt to be justified; therefore, no modifications are necessary.
We trust that this information will allow you to complete your review of this matter.
Very truly yours, b
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B. R. Sylvia Manager - Nuclear Operations & Maintenance :
"Information Recuired for Control Room Habitability Evaluation" Attschment 2:
"Chemic61 Storage and Ccntrol Room Habitability Evaluations" : Drawings ll715-FY-1A (marked up)
Attcchment 4: Drawings ll715-FB-23A and B l
- ~--..
i Information Required for Control Room Habitability Evaluation North Anna Power Station Note:
This information follows the format of Attachment I from Item 1
III.O.3.4, NUREG 073-~.
1 i
1.
Control Room Mode of Operation.
The control room emergency ventilation system for North Anna Units 1 and 2 provides for isolation of the control Icom zone, positive pressure in the control room zone, and filtered incoming air from the turbine building.
The main control and relay room complex is isolated by closing redundant dampers in both the normal supply end exhaust ducts, and.by shutting down exhaust fan 1-HV-F-15.
This is done either automatically by a safety injection (SI) signal or by manual initiation.
+
I Initial pressurization of the main control and relay room complex is provided from a bottled air system, _ consisting of primary and redundant-banks of air bottles.
The bottled air system is capable of developing.05 i
inch water gauge differential pressure for one hour.
The bottled air ll system is initiated either automatically by a safety injection signal or by manual initiation.
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4 Two redundant emergency ' ventilation fans and charcoal filter units are provided to supply incoming filtered air to the control room from the turbine building, and two redundant emergency ventilation fans and charcoal filter units are provided to supply incoming filtered air to the emergency switchgear rooms from the turbine building.
The four emergency ventilation fans are manually initiated.
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2.
Control Room Characteristics 3
2.a. The control room complex contains approximately 90,000 ft of air.
The main control and relay room complex contains a total of 3
l-approximately 320,000 ft of air, i
2.b. The control room complex consists of Units 1 and 2 main control I
rooms, Units 1 and 2 computer rooms, Units 1 and 2 air conditioning rooms, Units 1 and 2 logic rooms, a washroom, and a partitioned f
office.
l The main control and relay room complex consists of the control room complex, Units 1 and 2 emergency switchy:ar rooms, Units 1 and 2 relay rooms, units 1 and 2 air conditioning rooms, and battery rooms 1-II, 1-IV, 2-II, and 2-It.
2.c. The normal and emergency ventilation systems schematic is~ shown on drawings ll715-FB-23A and B (Attachment 4).
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2.d. Infiltration ldakage' is not postulated during the time the control
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room is isolated since the control room will be under positive pressure.
Exfiltration leakage rates are described in Section 6.4 of the FSAR.
2.e. HEPA filters are specified to have an efficiency of not less than 99.97 per cent (specification NAS-262).
The charcoal filters are two inches deep and are assumed per Reg. Guide 1.52, Table 2, to have an efficiency of 95 percent.
2.f. Closest distances between the reactor containment buildings and the control room air intakes are listed below and are shown on drawing Il715-FY-1A (Attachment 3).
Unit 1 Unit 2 Containment Containment Normal Air Intake 60' 280' l
Unit 1 Emergency Intake 120' 230' Unit 2 Emergency Intake 180' 150_'
2.g. Drawing 11715-FY-1A (Attachment 3) shows the plant layout, including chemical storage _ locations and control room air intakes.
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r 2.h. Shielding for the main control and relay room complex consists of the following:
28 inch' thick reinforced concrete walls; 24 inch thick reinforced concrete ceiling; at least 18 inch thick reinforced concrete walls for the stairwell in the cable tray room; 18 inch thick reinforced concrete walls for the emergency switchgear and relay rooms; sliding radiation shield doors for door openings; and concrete labyrinth arrangement for ventilatir,n duct openings for normal supply and exhaust ventilation ducts.
2.i. Dampers for control room isolation are specified to be pressure tight.
Dampers in the normal supply duct, ADD-HV-160-1 and
-2, are 18" by 20" and dampers in the exhaust duct, ADD-HV-161-1 and -2 are 18" by 18".
(Drawing 11715-FB-24C) 2.J. Chlorine and toxic gas detectors have been determined to be not required for North Anna.
2.k. Six self-contained breathing apparatus are normally maintained in the control room complex although neither the FSAR nor station procedures require a minimum number.
This number of apparatus is adequate since breathing apparatus is only necessary for those operators leaving the control room for short periods of time during an accident.
Additional breathing apparatus and air bottles are available in the Health Physics area.
Air bottles may be recharged using a cascade arrangement with greater than 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> supply capacity as required to be available for fire brigade use.
2.1. The bottled dry air bank consists of a minimum of 84 bottles and is sufficient for at least one hour's pressurization.
(Technical Specification 3/4.7.7).
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2.m. No food supply is permanently stored within the control room complex, but food is available in the station lunchroom and in the kitchen area of the office building.
This food supply is felt to be adeouate since the control rooin operators will be able to leave the control room for short periods of time while the control room is isolated.
Potable water for drinking and for the washroom is supplied to the control room complex from the domestic water system.
The domestic water system provides chlorinated water to the station from underground wells.
If the domestic water system is disrupted by a seismic event, bottled water could be brought from off-site.
First aid lockers are available within the plant and a first aid kit is usually available within the control room.
Station procedures do not state specific locations for first aid supplies.
2.n. During normal operations with two units operating, Technical Specifications require a minimum of two operators in each unit's j
control room with an additional five operators available on-site.
During emergency operations, all nine operators will most likely be l
located in the main control and relay room complex.
2.o. The Station Emergency Plan states that Vepco's Medical Director has I
approved the use of a thyroid blocking agent for a potential racioiodine inhalation situation by administering approximately eight drops of saturated potassium iodide solution in a cup of water.
The potassium iodide supply is available in the Health Physics area of the Service Building.
W/3859/10
3.
On-Site Storage of Chlorine and Other Hazardous Chemicals. Quantitles and locations of on-site chemical storage containers are summarized in Attacmant 2, which was included as Table 1 with our Letter Serial No.
155A dated March 17, 1980.
The evaluations for all chemicals stored onsite indicate that the worst-case concentration of the chemical within the control room is less than the toxicity limit for that chemical.
All cases are evaluated on the basis of no action being taken by the control room operator.
4.
Of f-site Manufacturing, Storage or Transportation Facilities of Hazardous Chemicals.
As stated in Section 2.2 of the FSAR, there are no manufacturing plants, chemical plants and storage facilities, or oil and gas pipelines within a five mile radius of the station.
There is no rail traffic except the station's rail spur, nor major water transportation routes within a five mile radius of the station.
The following rosos pass within five miles of the plant site:
1 l
Distance (M1) and Direction from Site Secondary State Road 652 1 1/2 S
Secondary State Road 601 2
NE Primary State Road 208 2
NW U. S. Route 522 5
WNW Page 6 of 7 W/3859/ll
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As stated in our letter $erial No.155 dated February 25, 1980, there is no specific data available on the types, quantities and frequency of chemical shipments along these routes; however considering the lack of chemical and industrial facilities along Routes 652, 601, and 208 and considering the distance between Route 522 ano the plant site, it is expected that there are no chemicals shipped along these routes at a frequency and weight great enough to require evaluation in accordance with the Regulatory Guide, and certainly none that would pose a hazard to the habitability of the control room.
5.
Technical Specifications 5.a. Standard technical specifications for a chlorine detection system are not applicable for North Anna since this system has been determined to be not required.
5.b. Technical Specifications 3/4.7.7 contain detailed requirements for verifying control room isolation, control room pressurization, and l
filter testing.
These requirements closely follow the standard technical specifications.
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ATTACHMENT 2 m 122980 Serial No. 155rA 1013 TABIE I - CID1ICAL S'IORAGE AND cot 7fROL NOOM IIABITABILITY EV. ALUATIONS (REVISION 1)
CID1ICAL NOFMAL S'IORAGE AREAS 1 WORS'r CASE NURE % CONTPOL M Distance Maxinun From C. R.
Type of Concentration Toxicity Quantity Iocation Air Intake Release in C.R.
(ppm)
Limit (ppn)
- 1. Hydrogen 700 lb Storage Tank, N.
N/A N/A Ilydrogen from any potential of Turbine Bldg.
release would be dispersed to the atmosphere before reaching the control rocnn air intake.
- 2. Carbon Dioxide 34,000 lb l-FP-TK-5, N. of 200' N. of 34,000 lb 16,500 10,000 or 2
Turbine Bldg.
Intake Instantaneous Asphyxiant 3g 12,000 lb l-FP-TK-6, Col.
9-G in Auxiliary Bldg.
- 3. Nitrogen 4,500 lb Tube Trailer, S.
420' S. of 4,500 lb 10,000 Asphyxiant 2
of Unit 1 Con-Intake Instantaneous tainment
- 4. Sulfuric Acid 1,700 gal 1-WT-TK-5, Col.
120' N. of 1,700 gal, 0.0154 0.5 8-B in Turbine Intake Evaporation Bldg.
- 5. Armonium Ilydroxide 55 gal Col. 7-C in Tur-40' below 55 gal, see tbte 5 100 (30% solution by bine Bldg.
Intake Instantaneous weight) 55 gal Col. 15 -C in Turbine Bldg.
55 gal Drum Storage Area Adjacent to Ware-house 2
PSE&C 03128e 122980 Serial No. 155A 1013 2
- 6. Acetone 55 gal Drum Storage Area 420' E. of 55 gal, 180 2,000 Adjacent to Ware-Intake Evaporation house 2 2
- 7. Hydrazine 55 gal-Warehouse 2 420' E. of 55 gal, 15 See Note 6 (35% solution by Intake Evaporation weight)
- 8. Boric Acid 7,500 gal 1-Cil-TK-1A, Col.
N/A N/A Insignificant vapor given off (22,500 ppn 9-II in Aux. Bldg.
at ambient temperature solution) 7,500 gal 1-Cll-TK-1B, Col.
9-11 in Aux. Bldg.
7,500 gal 1-CII-TK-lC, Col.
9-11 in Aux. Bldg.
9.. Sodiun ifydroxide 700 gal 1-Wr-TK-18, Col.
N/A N/A Insignificant vapor given off (25% solution by 9-B in Turbine at anbient topperature weight)
Bldg.
- 10. Sodiun Ilyochlorite 15,000 gal 1-SW-TK-3A, Ser-N/A N/A Insignificant vapor given off (15% solution by vice Water Ptmp-at ambient tenperature weight) house 15,000 gal.
1-SW-TK-3B, Ser-vice Water Ptmp-house 3,000 gal 1-BC-TK-2, Col.
10-B in Turbine Bldg.
- 11. Calgon CL-14 3,200' gal 1-BC-TK-1, Col.
N/A N/A Insignificant vapor given off 2 -X in Turbine at ambient tarperature Bldg.
500 gal 1-SW-TK-4,'Scr-vice Water Ptmp-house 4
PSE&C 03-1960- 122980 Serial No.165tr 1013
- 12. Urea Formaldyhyde 4,500 gal 1-IW-TK-16A, De-N/A N/A Insignificant vapor given off contamination at anbient tortperature Bldg.
1-IN-TK-16B, De-contamination Bldg.
1.
Quantities less than 100 pounds and chemicals stored and used in solid form are not listed.
2.
Evaluations are based on control room normal ventilation intake and air exchange rate of.92 voltzne changes per hour for those chemicals so noted.
3.
Carbon dioxide is an asphyxiant according to Sax's " Dangerous Properties of Industrial Ittterials - Fifth Edition" and as such would have a toxicity limit of 33 percent.
4.
Evaluations are based on control room mergency ventilation intake and air exchange rate of.34 volume changes per hour for those chmicals so noted.
5.
'Ihe worst case exposure to the control room from anmonium hydroxide would be the rupture of a 55 gal, drum at the chmical addition area in the Turbine Building concurrent with Turbine Building ventilation systs failure and with the control room mergency ventilation systs operating.
In order to achieve an aninonia concentration of 100 ppn in the control rom in this case, greater than 17 percent of the armonia release would have to be brought into the control rom through the air intake. Considering the density of armonia, the turbulent air flow that would exist in the Turbine Building, and the distance from the point of release to the air intake, it is not felt to be possible to achieve a concentration of 100 ppn in the control room.
6.
A toxicity limit for hydrazine is not given in Regulatory Guide 1.78, but is defined as being the maxinum concentration that can be tolerated for two minutes without physical incapacitation of the average human (i.e. severe coughing, eye burn, or severe skin irritation). There is nothing in the available literature to indicate that a one-time exposure to a con-centration of 15 ppm for two minutes will cause any effect on the average hunan; therefore it is concluded that the tox-ity* limit as defined above is greater than 15 ppn for hydrazine. 'Ihe major concern for Hydrazine is from dermal exposure or fran long-term exposure, rather than from short-term inhalation exposure.