ML19340D865

Control Room Habitability Study

ML19340D865
Person / Time
Site:	Cooper
Issue date:	12/12/1980
From:	STONE & WEBSTER ENGINEERING CORP.
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ML19340D858	List: ML19340D865
References
13095.16, NUDOCS 8101050473
Download: ML19340D865 (35)

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CONTROL ROCM HABITABILITY STUDY COOPER NUCLEAR STATION prepared for NEBRASKA PUBLIC POWER DISTRICT December 12, 1980 J.O. !b.13095 16 Stone & Webster Engineering Corporation Denver Operations Center Denver, Colorado l

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TABLE OF CONTENTS 4

Section Title Page 1

INTRODUCTION 1-1 2

SITE CHARACTERISTICS 2-1 2.1 Geography, Plant !ayout, and Control Room Characteristics 2-1 2.2 Design Basis Meteorology 2-2 23 Type and location of Potential Toxic Gas Hazards 2-2 3

DESIGN BASIS RADIOLOGY 3-1 31 Methodology 3-1 32 Results 3-1 4

T0XIC GAS REVIEW u-1 4.1 Methodology 4-1 4.2 Results 4-2 5

CONTROL ROOM PROTECTION 5-1 51 Ventilation System 5-1 5.2 Emergency Provision 5-1 6

ACTION 6-1 REFERENCES 1

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_ LIST OF TABLES Table No.

Title 2-1 Onsite Potential Gas Sources 2-2 Offsite Potential Gas Sources 4-1 Evaluation of Control Room Habitability LIST OF FIGURES Figure No.

Title 2-1 Geography within 5 mi. of the Site 2-2 Site Arrangement 2-3 Control Room HVAC Flow Diagram 4-1 Concentration Plot, Chlorine Truck Accident 4-2 Concentration. Plot, Chlorine Train Accident 4-3 Concentration Pict, Anhydrous Ammonia Barge Accident

'4 -4 Concentration Plot, Carbon Dioxide Accident 4-5 Concentration Plot, Nitrogen Accident 4-6 Concentration Plot, Sulfuric Acid Accident 4-7 Concentration Plot, Sodium Hydroxide Accident 4-8 Concentration Plot Ammonia Barge Accident With l

225 cfm Makeup 4-9 Concentration Plot, Chlorine Train Accident With 225 cfm Makeup l

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s SECTION 1 INTRODUCTION This report was prepared in response to the Nuclear Regulatory Commission (NRC) requirement that nuclear power plant licensees review their facilities to assure that control room operators will be adequately protected against the effects of an accidental release of toxic and radioactive gases, and that the nuclear power plant can be safely operated or shut down under design basis accident conditions. This requirement is identified in Section III.D.3 4 of NUREG-0660 and is clarified in NUREG-0737.

In accordance with this requirement, the Cooper Nuclear Station (CNS) cot 'ol room habitability design provisions were reviewed against Regulatory Guides 178 and 1.95, Standard Review Plan Sections 2.2.1, 2.2.2, 2.2 3, and 6.4, and K. G. Murphy and K. M. Campe, " Nuclear Power Plant Control Room Ventilation System Design for Meeting General Design Criterion 19" (Ref 1).. In accordance with I&E Circular 80-03, for those areas where the degree of protection is significantly less than that specified, controls or modifications were proposed.

This report provides a description of the site characteristics important to toxic and radioactive gas hazards,~ including geography, plant layout, control room characteristics, type and location of potential toxic hazards, and design basis meteorology.

This habitability evaluation identifies maximum credible accidents, predicts concentrations in the control room, and compares these concentrations with the toxicity and dose limits of Regulatory Guide 1.78 and Standard Review P1,in 6.4 For hazards that exceed these limits, transient curves are presented so that required system response times and maximum concentrations may be established.

1-1

SECTION 2 SITE CHARACTERISTICS 2.1 Geograchv, Plant layout, and Control Room Characteristics Site geography is well described in Section 2 of the Cooper Nuclear Station FSAR (Ref. 2).

The station site is located in Nemaha County, Nebraska, en the west bank of the Missouri River at river mile 532 5 in a location referred to as the Lower Brownville Bend.

The overall site and vicinity plan is shown in Figure 2-1, including identificaton of nearby industrial and transportation activities.

The plant layout, showing the locations of the Control Building, Reactor Building, Turbine Building, and various on-site =aterial l

storages, is shown in Figure 2-2.

The Control Room is located in the Control Building, as shown in Figure 2-2, with west-facing air intakes located on the western end of the Control Building roof. The normal ventilation intake rate to the Control Room is 12,400 cfm. There are two emergency flow modes:

1)

Upon detection of radiation at the air intake, outside makeup air is automatically cut back to 225 cfm, and routed through a makeup bypass filter train consisting of a prefilter, a HEPA filter, and a cartridge-type activated charcoal filter. This makeup flow is then mixed with the recirculation flow and is subsequently filtered, conditioned, and returned to the i

control room, as shown in Figure 2-3 I

i 2)

Upon detection of smoke in the ventilation systems, all outside air is shut off, since the makeup bypass filter train will be of little value in adsorbing the toxic substance.

This flow mode will also be initiated manually during a toxic gas accident.

In this case, the only outside air makeup is leakage through the isolation dampers, which has been conservatively calculated at 225 cfm. This inleakage is mixed l

with recirculation flow as above and returned to the control i

room, as shown in Figure 2-3 The control room is 69'-6" X 64'-1" X 14'-8" or 65,300 cu. ft. in volume. A dropped ceiling 11'-4" above the floor, a normally isolated 17,840 cu. ft. access area, and a ten percent allowance for equipment leaves a conservative control room free air space volume l

of 33,060 cu. ft., into which the normal ventilation flow is 9300 cfs. The control room air intake is elevated 54 ft. above grade

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level.

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2-1 1

2.2 Design Basis Meteorology The control room X/Q calculations for release of radionuclides are based on wind Stability Class F, a 98m elevated release point, and fumigation conditons described in Regulatory Guides 13 and 1.145 The Annual Report provided in the FSAR Response to Question 2.26 (Ref. 2) provides the meteorological onsite data needed for the X/Q values. Murphy and Campe methods (Ref.1) and Regulatory Guide 1.145 identify the technique that is to be utilized to evaluate the X/Q values to be used in control room radiological calculations.

The X/Q's calculated based on the above are:

Time Period X/Q (sec/m3) 0 - 1/2 h 3 03 X 10-4 1/2 - 8 h 8.19 X 10-8 8 - 24 h 4.68 X 10-8 1-4d 4.11 X 10-8 4 - 30 d 2 73 X 10-8 The calculations of toxic substance dispersion are based on methodology described in NUREG 0570. Worst case meterological conditions are assumed'; for ground level releases, the worst case will result at low wind speeds, under stable conditions.

23 Type and Location of Potential Toxie Gas Razards According to Regulatory Guide 1.78, both onsite and offsite potential toxic gas hazards must be considered. Offsite sources are stationary sources within 5 miles of the control room intakes, and mobile sources (i.e., truck, train, and barge) that frequently pass within 5 miles of the intakes.

Onsite sources are identified in Table 2-1.

These include liquid nitrogen (an asphyxiant) for containment atmospheric dilution, carbon dioxide for fire protection, and sulfuric acid and sodium hydroxide used in water treatment. Other hazardous materials are stored in smaller quantities (less than 100 lb.) well removed from the control room air intake. Hydrogen is discounted because of its bouyancy. Onsite transportation of hazardous materials is less of a hazard than their storage because of the distance of the access road frcm the air intake.

It is noted that any chlorine used for water i

l treatment is in a solid form and does not constitute a toxic gas I

hazard.

Potential offsite sources include nearby industries and transportation activities. See Table 2-2.

There are only a few industries within 5 miles of the site, most notably a meat packing plant, a soon to be completed ethanol plant, and grain elevators.

None of these local plants store large quantities of hazardous gases 1

2-2

or gas-producing materials that would affect control room habitability at CNS. Offsite transportation activity is summarized as follows:

1)

Major truck traffic that would carry toxic materials with the frequency defined in R.G.178 (over ten loads / year) could travel over routes I-29 east of CNS in Missouri and U.S.136 north of CNS. The closest point is at the U.S.136 bridge over the Missouri River, 2 5 miles north of the air intake.

A complete listing of all toxic materials transported by truck is not yet available, so for the purpose of this report, the most toxic substance was assumed to be chlorine.

As established by the Chlorine Institute, Inc., the maximum truck tank size is 20 tons.

2)

Rail traffic carrying toxic materials within the frequency guidelines of R.G.178 (over 30 loads / year) travels the Burlington Northern tracks 2.8 miles east of the CNS air intake.

Again, the transported toxic substance was assumed to be chlorine. The maximum rail car tank size is 90 tons as established by the Chlorine Institute, Inc.

3)

Barge traffic past the power plant on the Missouri River is monitored by the U.S. Army Corps of Engineers. They have indicated that chlorine is not shipped and the most significant substance that is shipped with the frequency defined in R.G.1.78 (over 50 leads / year) is anhydrous ammonia. A normal barge can carry up to four tank's totallir4 2900 tons (725 tons / tank). At its closest point, the river bank is 460 ft. east of the control room air intake.

1 1

l 2-3

TAHLE 2-1 ONSITE POTENTI AL G AS SOURCES IIAZARDOUS STOHED QUANTITY DISTANCE, DIRECTION FROM HATEHIAL AND CONTAINEH TYPE IDCATION CONTROL ROOM INTAKES (PT)

Carbon dioxide 10,000 lb. tank (liquid)

'Ibrbine Bldg., basement 260 E (76)751b cylinders Diesel Gen. Bldg.

220 ENE Nitrogen 16,000 gal. tank (liquid)

South side of Reactor 220 S Bldg. Rail Car Airlock Sulfuric acid 10,500 gal. tank Water Treatment bldg.

280 E Sodium hydroxide 10,500 gal. tank Water Treatment bldg.

280 E Ilydrogen 5 cylinders Gas Storage Bldg.

425 E

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TABLE 2-2 OFFSITE POTENTIAL. GAS SollRCES IIAZARDOUS QUANTITY, SIZE DISTANCE, DIHECTION FROM MATEHIAL AND TYPE OF CONTAINER LOCATION CONTH01. ROOM INTAKES (PT)

Chlorine Truck Tanker - (1) 20 ton U.S. Ht 136 Bridge 13,200 NNW tank over Missouri River Rail Tank Car - (1) 90 ton Burlington Northern 14,800 E

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SECTION 3 DESIGN BASIS R ADIOLOGY 31 Methodolorv The control room is designed to protect personnel from radiological hazards in accordance with General Design Criterion 19 and Standard Review Plan 6.4 Limits of 5 rem whole body garma, 30 rem thyroid, and 30 rem beta skin should not be exceeded for the duration of the accident considering major sources of radiation.

Radiation doses to control room personnel result from three major sources. The first one is due to a direct gamma radiation from fission products in the reactor building (including the core spray pipe, residual heat removal system, and suppression pool ventline) after an accident. The FSAR, Section 10 5 (Ref. 2) provides an evaluation of the direct doses contributed by the secondary containment and core spray piping sources.

The second contribution to dose results from shine from the semi-infinite cloud external to the control room building. The source terms include leakages from the primary containment and main steam isolation valves. The resulting dose was calculated to be negligible compar9d to the direct dose.

The third dose contributions result from an intake of gaseous fission products into the control reem which enter via the charcoal filtered ventilation system, and an unfiltered infiltration. For the intake and infiltration doses, the gamma dose is computed based on a finite cloud model, and the beta skin dose a semi-infinite cloud model. The thyroid dose is computed using the conversion-factors given in TID 14844.

32 Results The following models and assumptions (FSAR Section 10 5 and NUREG-0737) for source terms and the control room building were used to evaluate the radiological consequences of the postulated loss of coolant accident.

SOURCE TERMS 1.

Fission product core inventory is based on core thermal 2846 MW(t) and time at constant power of 1000 days.

2.

100 percent of the noble gases in the reactor, 25 percent of the iodines and 1 percent of the particulates instantaneously become available for leakage from the primary containment.

3-1

3 100 percent of the noble gases, 50 percent of the iodines, and 1 percent of the particulates are assumed to remain in the reactor coolant and suppression pool.

4.

The primary containment leak rate is 0.635 percent per day for 30 days.

5 The total leak rate from the main steam isolation valves is 10 cfm.

6.

The escaping gaseous effluents immediately flow through the standby gas treatment system and the stack without mixing in the secondary containment building.

7 The standby gas treatment systems remove one secondary containment air volume per day.

8.

95 percent of the iodine and 99 percent of the particulate entering the standby gas treatment is retained by charcoal-HEPA filters.

9 The primary containment free volume is 1.45 X 105 ft3 and 3

the secondary containment free volume 7 95 X 105 ft,

CONTROL ROCM 1.

Air intake flow rate is 225 cfm.

2.

Control Rocm volume (conservative) is 6.51 X 104 3

ft.

3 Intake carbon filter efficiency is 95 percent.

4.

'4all thickness is 2-ft-thick concrete.

5 Infiltration flow rate is 10 cfm (Ref.1).

6.

The radiation monitoring system is designed to turn on the j

emergency ventilation system im=ediately following a major j

accident.

The total 30-day integrated LOCA whole-body gamma, thyroid and beta 6

skin doses based en the above are computed using the QADMOD point kernel computer code (Ref. 3) and Dragon 3 computer code (Ref. 4) as follows:

TOTAL ?O-DAY INTEGRATED DOSE frem)

Gamma Thyroid Beta 1.76 1.09 0.27 These are within the limits of General Design Criterion 19 3-2 l

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SECTION 3 T0XIC GAS REVIEW i

4.1 Methodology To obtain the most conservative results, it was assumed that the entire container of toxic materials identified in Section 2 3 herein ruptures. Part of the substance vaporizes into a cloud or plume i

which disperses into the atmosphere and moves toward the control t

room air intake under the design basis meteorology conditions of F-Stability and im/sec.

l The actual amount of vapor immediately vaporized depends on the physical characteristics of the spilled substance. A portion of i

compressed and liquified gases and low boiling point liquids will instantaneously flash, followed by vaporization of the remaining liquid as it draws heat from its surroundings.

For high boiling point liquids, the substance will evaporate into the atmosphere much more slowly.

The dispersion of onsite and offsite spills is calculated using techniques presented in Appendix 3 of Regulatory Guide 1.78, as amplified in NUREG-0570. Chemical concentrations, both outside and inside the control room are calculated as a function of time following a postulated accidental release, using a computer program which utilizes the NUREG-0570 techniques (Ref. 5).

For low boiling point liquids and liquified gases, the effect of a puff release and a ground-level plume are considered.

For those chemicals which are stored as gases, only the effect of a puff release is considered.

Liquids which have boiling points above the ambient temperature contribute only a ground-level plume due to evaporation from the spill.

The input data to the program consisted of the design basis meteorology, the control room volume and ventilation rate, the 4

t amount of chemical released, the chemical physical properties, and the distance from the point of release to the control room intake.

The emission height and receptor height were both assumed to be zerc for heavier-than-air gases, following the recommendation of

)

NUREG-0570. For lighter-than-air gases, the emission height was set equal to the receptor height (54 ft above grade).

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1 4.2 Results j

The results of this analysis are summarized in Table 4-1, which compares maximum predicted chemicti concentrations in the control room with published toxicity limits of Regulatory Guide 1.78 or with limits determined from the NIOSH Registry of Toxic Effects of Chemical Substances. Concentration level plots are contained in Figures 4-1 to 4-7.

Table 4-1 identifies three substances that produce concentrations in excess of the limitations -- chlorine, I

anhydrous ammonia, and carbon dioxide. Although in each of these cases the toxic limits are exceeded, presently installed equipment, including self-contained breathing apparatus, provides sufficient operator protection.

The following is a discussion of the results for each of these chemicals:

1)

Anhydrous Ammonia The computer program that was used to generate the ammonia l

plot in Figure 4-3 did not take into account the bouyancy of l

the vapors.

A supplemental analysis performed per NUREG/CR-1152 (Ref. 6) shows that when bouyancy is considered, the ammonia " cloud" will rise so fast that by the time it has traveled the 140m horizon *al distance to the control room intake, its concentration will have been diluted by a factor i

of 100. This would still result in a control room i

concentration in excess of the A.G.178 limit.

However, ammonia is quite readily detectable by the operators and the ventilation intake flow can be readily shut down. This will i

further reduce and delay the maximum concentration as shown in Figure 4-8, so that there will be sufficient time to don l

respirators.

As discussed in Section 5.2, there are adequate respirators available for the anticipated duration of the l

accident, approximately twelve hours.

Also, with the reduced l

intake rate, protective clothing will not be required.

2)

Chlorine The chlorine cloud for both the postulated rail car accident and truck tanker accident will require more than an hour to reach the CNS centrol room air intake.

Because of the i

communications established between CNS personnel and local law enforcement personnel as a part of the Emergency Plan, this hour is sufficient time for notification, isolation of the ventilation system, and donning breathing apparatus so that safe control of the plant is maintained. Although the chlorine concentration plot in Figure 4-2 shows concentrations significantly above the R.G. 1 78 toxicity limit, if the air intake is shut off, the maximum concentration is actually less than 10 times this limit, as shown in Figure 4-9 Protective 4-2 l

clothing is not considered to be required at these levels.

Also, site winds blow at im/see from either NNW (truck accident) or ENE (train accident) less *5an 0 5 percent of the time.

3) carbon Dioxide The calculated CO2 concentration is probably unrealistically high in that it does not take into account the fact that the CO2 will be diluted within the Turbine Building prior to its release and dispersion.

Liquid CO2 is stored in the basement of the Turbine Building in a 10,000 lb. tank. Upon its accidental release, it would expand into approximately 2,142,000 cu ft. of the Turbine Building volume before being exhausted at 152,000 cfm. There would also be a building wake effect in that the heavier-than-air CO2 would have to exit the fan room, climb 70 ft over the Turbine Building, and then fall 50 ft. to reach the control room air intake. Further, the calculated maximum concentration of 1331 g/m3 is not that much higher (considering the above conservatisms) than the NIOSH ceiling limit of 54 77 g/m3; this concentration allows ten minutes for an operator to den breathing apparatus before his judgement and coordination are affected.

Also, site winds blow at im/see from the east less than 0 5 percent of the time.

4-3

i TABLE 4-1 EVAL.UATION OF CONTROL ROOH IIABITABILITY llAZARDOUS H.G. 1 78 PEAK CONCENTRATION TIME TO TIME TO GET BACK RELATIVE HATEHIAL T0XIC LIMIT IN CONTRCL R00H(1)

REACil T0XIC BELOW TORIC TOXICITY (2)

(g/m3)

(g/m3)

LIMIT (sec)

LIMIT (sec)

Anhydrous

.070 202.8 37 42,100 2,897 Ammonia Chlorine

.045 5.65 4,200 10,700 125 Carbon 1.84(3) 133 69 1,634 72 Dioxide Nitrogen 174(4) 110.4 0.4 Sulfuric

.002 4 5 E-4 0.225 Acid Sodium

.002 1.8 E-5 0.009 liydroxide 3

(1)

Peak concentrations and accident durations assume full ventilation flow rates.

(2)

Relative toxicity is defined as the conservatively calculated peak control room concentration divided by the toxic limit.

(3)

NIOSil ceiling is 54 77 g/m3 (4)

This is not a R.G.178 limit, but rather was calculated based on maintaining a minimum 165 oxygen concentration.

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!4

SECTION 5 CONTROL ROCM PROTECTION The CNS Control Room design and operational features are reviewed against SRP 6.4 to determine their effectiveness in mitigating the consequences of postulated accidents.

51 Ventilation system The CNS control room ventilation system is designed to maintain the control room at about 1/4" W.G. positive pressure by supplying air at a high enough pressure that even after system losses and the booster exhaust fan pressures are accounted for, the control room pressure is still positive. During emergencies, the normal supply is shut off and either (1) a 225 cfm makeup bypass train, including a pre-filter, HEPA filter, and carbon adsorption filter, is operated, or (2) all outside makeup is shut off, as discussed in 2.1 above. The activated carbon has an iodine removal efficinney of 99 97 percent.

Its effectiveness at removing chlorine ar.d ammonia is undocumented but is less than that for iodine. The radiation monitor that autcmatically switches to the makeup bypass train meets single failure criteria since it is powered from an emergency bus and since it includes three separate dectectors (for iodine, particulates and gas).

The control room area construction is tight, with sealed cable penetrations, tight fitting sealed doors, and tight ventilation louvers with interlocking neoprene edges. The area serviced by the control room ventilation system includes the control room and the cable spreading room, including kitchen and sanitary areas.

Although the cable spreading room does not require access during accident conditions, it contains the air conditioning unit and is a sealed volume, so it does not adversely affect system function.

The normal flow pressurization rate is 11.4 volume changes per hour, and flow rates are periodically verified to be within ten percent of l

their design value. The emergency flow pressurization rate is 0.21 volume changes per hour, and flow rates are also periodically verified to be within ten percent of their design value.

l In light of the above features, the CNS control room ventilation l

system is considered to meet the intent of SRP 6.4.

l 5.2 E=ergency Provisions The CNS control room has on hand two self-contained breathing masks and two spare tanks.

Immediately outside the room are five additional units. There are an additional 26 Scott air pacs and 15 spare tanks throughout the plant, and there is the capability to recharge 180 tanks from stored air bottles. This air system is 5-1

intended to supply a six-man emergency team with three tanks per hour for ten hours before an off-site supply would be required. Two operators are sufficient to run the plant, and a security guard must be on duty at the security desk just outside the control room operating area.

The five Scott air pacs located just ouside the control room are accessible to the security guard and an STA, should he be required, and single failure criteria has been met.

Reg.

Guide 1.78 suggests that a six-hour air supply for a five-man emergency team would be adequate.

Although protective clothing is not considered to be required for any of the postulated accidents, there are varying degrees of individual sensitivity. The anti-contamination protective clothing available at CNS is effective for hazardous substances discussed herein.

The control room normally stores between 20 and 150 TV dinners as an emergency food supply for the emergency team.

Also, there is a 6,000 gallon potable water storage tank.

There is no potassium iodide stcred, since none is needed because of the low 30-day integrated thyroid dosa rate, (see Section 3 2).

5-2

SECTION 6 ACTION An emergency procedure will be written by January 1,1982, which will discuss the necessary actions and responsibilities for toxic gas releases in the plant vicinity.

Other than the lack of a written emergency procedure, there are no areas where the degree of protection against toxic gas hasards is significantly less than that specified in the SRP's or Regulatory Guides.

i l

l 6-1 l

i REFERENCES 1.

K. G. Murphy and K. M. Ca:pe, " Nuclear Power Plant Control Room Ventilation System Design for Meeting General Design Criterion 19",

135h AEC Air Cleaning conference, August 1974.

2.

Final Safety Analysis Report, Cooper Nuclear Station, Nebraska Public Power District.

3 E. T. Boulette, et al., "?oint Kernel Gatma Transport-QADMOD",

NU-137, Stone & Webster Engineering Corporation, February,1980.

4.

J. N. Ma=awi, et al., "Cose and Radioactivity from Nuclear Faciltiy Gaseous Outflows - Dragon ~ 3", NU-115, Stone & Webster Engineering Corporation, February 1977 5

A. Easprak, " VAPOR", EN0199, Stone & Webster Engineering Corporation, Septe=ber 1930.

a 6.

NUREG/CR-1152, "Reco:: ended Methods for Estimating Atmospheric Concentrations of Hazardous Vapors After Accidental Releases Near Nuclear Reactor Sites", J. R. Connell and H. W. Church, April 1980.

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INFORMATION REQUIRED BY NUREG-0737, PARAGRAPH III.D.3 4 FOR INDEPENDENT CONTROL ROOM HABITABILITY EVALUATION 1.

The control room is normally pressurized using rough-filtered outside air.

During a radiological accident, outside makeup flow is reduced and diverted through a bypass filter train consisting of a pre-filter, a HEPA filter, and a carbon adsorber unit, while the control room air volume is recirculated through an air conditioning unit. During a toxic gas accident, all outside makeup air is shut off and the control room air volume is recirculated.

2.

a.)

The control room volume is 65,300 cubic ft.

However, there is a nor= ally-closed access area, a suspended ceiling, and a ten percent equipment volume that should be taken into account; this leaves a free air volume (for toxic gas concentrations) of 33,050 cubic ft.

b.)

The control room emergency zone includes the control room, kitchen, toilet, and access area around the control room.

Also serviced by the control room ventilation system is the cable spreading area, which is a sealed volume.

c.)

The control room ventilation system schematic is shown on Burns &

Roe drawing no. 2019 d.)

The infiltration leakage rate is 225 cfm.

e.)

The efficiency of the HEPA filter in the 225 cfm makeup bypass filter train is 99 percent.

The efficiency of the charcoal adsorber is 95 percent.

f.)

The closest distance between the containment and the control room air intake is 40 ft.

g.)

The control room layout is shown on Burns & Roe drawing no. 4526; l

air intake locations are shown on Burns & Roe drawing nos. 2217 l

and 2218; the site plan is shown on Burns & Roe drawing no. 4003; and a marked-up sketch of site locations showing dimensions is also attached.

h.)

The control room is surrounded by 2 feet of concrete shielding in the walls and roof, there are three 1-ft. concrete floors below it, and all openings are protected by shield walls so that there j

are no direct streaming paths.

i.)

Control room dampers are capable of closing in 2-5 seconds.

I Damper leakage is approximately 225 cfm through one 2 sq. ft.

damper and two 0 35 sq. ft. dampers.

J.)

There are no chlorine or other toxic gas detectors.

l i

k.)

There are two self-contained breathing devices and two spare tanks in the control room. There are five 3c 4L air pacs just outside the control room and another 26 Scott air pacs and 15 spare tanks located throughout the plant.

1.)

There is an on-site bottled air supp'y capable of recharging 180 tanks; at the worst case of three tangs per man per hour (heavy exertion), this is a 60 =an-hour air supply.

l m.)

There is an emergency food supply that would last a four-man team an average of five days. The potable water supply is seismic class 2 and is capable of supplying a four-man emergency team for a month.

n.)

The control room can support four men for at least 7 5 days, completely closed and sealed.

o.)

There is no potassium iodide drug supply.

3 a.)

chlorine is stored onsite in solid non-hasardous form. The hazardous materials that are stored onsite are identified as follows:

MATERIAL CONTAINER SIZE, TYPE QUANTITY OF CONTAINERS CO2 10,000 lb. tank 1

75 lb. cylinder 76 Liquid Nitrogen 16,000 gal, tank 1

Sulfuric Acid 10,500 gal. tank 1

Sodium Hydroxide 10,500 gal. tank 1

Hydrogen 60 lb. cylinder 5

b.)

The distances between the hazardous material storage and the control-room air intake are:

CO2 260 ft. (tank) 220 ft. (cylinders)

Liquid Nitrogen 220 ft.

Sulfuric Acid 280 ft.

Sodium Hydroxide 280 ft.

Rydrogen 425 ft.

4.

a.)

Offsite manufacturing, storage, and transportation facilities for hazardous chemicals within 5 miles are identified as follows:

U.S. Rt. 136 Chlorine transport Burlington Northern R.R.

Chlorine transport Missouri River Anhydrous ammonia transport e

b.)

The closest distances of these sources to the control room air intake are:

U.S. Rt. 136 2.5 mi. NNW Burlington Northern R.R.

2.8 mi. E Missouri River 460 ft. ENE c.)

Hazardous chemicals are transported in the following container sizes:

Chlorine truck tanker 20 tons Chlorine rail tank car 90 tons Ammonia barge tank 725 tons d.)

Frequency of hazardous chemical transportation traffic is as follows:

Chlorine truck shipments

<10 'per year Chlorine rail shipments

<30 per year Ammonia barge shipment

<50 per year 5

a.)

There is no chlorine detection system.

b.)

The Technical Specifications require the following control room emergency, filtration system tests:

1.)

The supply fan and dampers are tested for operability every three months.

2.)

Pressure drop across each filter and the filter system is tested once per year.

3.)

A DOP test for particulate filter efficiency greater than 99 percent for particulate greater than 0 3 micron size is conducted once per year 4.)

A Freon-112 test for charcoal filter bypass as a measure of filter efficiency of at least 99 percent for halogen removal-is conducted once per year.

5.)

A sample of the charcoal filter is analyzed once per year to assure halogen removal efficiency of at least 99 percent.

6.)

The filter absorption is demonstrated at least once each five years.

7.)

Operability of main control room air intake radiation monitors is tested once per month.

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