Text

Control Room Habitability Study for Quad Cities 1 & 2, Final Rept
	ML17194A372
Person / Time
Site:	Dresden, Quad Cities
Issue date:	12/31/1981
From:	; BECHTEL GROUP, INC.
To:	;
Shared Package
ML17194A371	List: ML17194A370; ML17194A372; ML20039C404;
References
	RTR-NUREG-0737, RTR-NUREG-737, TASK-3.D.3.4, TASK-TM NUDOCS 8112290308
	Download: ML17194A372 (102)
	v • d • e

."i CONTROL* ROOM* HABI!I'ABILITY*STUDY FOR QUAD* CITIES .UNITS .1 AND *2 COMMONWEALTH EDISON COMPANY Prepared By Bechtel Power Corporation Ann Arbor, Michigan Final Report November 1981 Revised December 1981

\

REGULATORY DOCKET FILE COPY

, - * - *- - .._____,.....,. _. -*---~-- ... --+--;;- .. --*-*i

\ . 8112290308

. ~:~ PDR ~DOCK .osoqo~g~

811~217 i..

~ '=- , ___ _j _ 1__

\

CONTROL ROOM HABITABILITY STUDY TABLE OF CONTENTS Page

1.0 INTRODUCTION

1-1 2.0 EXISTING DESIGN 2-1 3.0 TOXIC CHEMICAL SURVEY 3-1 4.0 RADIOLOGICAL ANALYSIS 4-1 5.0 PROPOSED HVAC DESIGN MODIFICATIONS 5-1 6.0 RECOMMENDATIONS 6-1 FIGURE 1 Quad Cities Control Room HVAC Schematic APPENDIXES

-* A B

c NUREG 0737, Item III.D.3.4 N~C-Requested Information Required for Control Room Habitability Evaluation Summary of *Of fsite Toxic Chemical Survey A-1 B-1 C-1 Table C-1: Potentially Toxic Chemicals Stored Within the Quad Cities Site Boundary Table C-2: Potentially Toxic Chemicals Stored at Fixed Facilities Within a 5-Mile .Radius of Quad Cities Table C-3: Potentially Toxic Chemicals Tran$ported on Barges within a 5*-Mile Radius of Quad Ci ties Table C-4: Potentially Toxic Chemicals Transported on Railroads Within a 5-Mile Radius of Quad Cities Table C-5:. Potentially Toxic Chemicals Transported on Highways Within a 5-Mile Radius of Quad Cities ii

Table of Contents (continued)

Appendixes (continued)

D Radiological Analysis for Control Room D-1 Habitability Following a DBA-LOCA Table D-1: Loss-of-Coolant Accident Parameters Tabulated for Postulated Accident Analysis Table D-2: DBA-LOCA Radiological Consequences iii

1.0 INTRODUCTION

A study is being conducted of the Quad Cities Units 1 and 2 control room habitability during toxic gas releases, radioactive gas releases, and direct radiation resulting from design basis accidents (DBAs). The study includes a survey.of potential onsite and offsite sources of toxic chemical hazards which could jeopardize control room habitability, along with an analysis of control room doses resulting from a OBA loss-of-coolant accident (LOCA). The study is intended to satisfy the requirements for control room.habitability as provided in Item III.D.3.4 of NUREG 0737, Clarification of TMI Action Plan Requirements. A copy of NUREG 0737, Item III.D.3.4 is provided as Appendix A.

The following report swnmarizes the results of the study. The analysis of the onsite and offsite toxic chemical survey is provided in Section 3.0. The analysis of the radiological cal-culations is provided in Section 4.0. The recommended design modifications that address those results.are included in Section s. A response to the *Request for Information Required for Control Room Habitability Evaluation,* as contained in Attach~

ment 1 to Item III.D.3.4 of NUREG 0737, is provided as Appendix B*

1-1

2.0 EXISTING DESIGN The Quad Cities Units 1 and 2 control room is located in the service building at elevation 623'. The existing HVAC system which supplies conditioned air to the control room is located in the service building at elevation 623'. This system also pro-vides conditioned air to the computer room (elevation 595'),

auxiliary electric equipment room (elevation 595'), cable spreading room (elevation 609'), HVAC equipment room, and mis-cellaneous areas. The HVAC system operates continuously to maintain 75F in the control room for personnel comfort and safety and equipment reliability. FSAR Subsection 10.10.4 provides further details on the control room HVAC system *

2-1

3.0 TOXIC CHEMICAL SURVEY 3.1 OVERVIEW A survey for potentially toxic chemicals stored or transported onsite or within a 5-mile radius offsite of Quad Cities Units 1 and 2 was conducted in accordance with the criteria outlined in NUREG 0737, Item III.D.3.4. The following discussion provides the survey methods, analysis methods and results, and conclusions of the toxic chemical survey.

3.2 ONSITE SURVEY METHODOLOGY The onsite survey was conducted to identify .chemicals stored within the plant boundary. A list of potentially toxic onsite chemicals is provided in Table C-1 of Appendix c. The results of the onsite survey analysis are provided in Section 3.5 below.

3.3 OFFSITE SURVEY METHODOLOGY The offsite survey was conducted to identify chemicals stored or transported within a 5-mile radius of the Quad Cities site.

Fixed industrial, municipal, and bulk storage facilities, as well as pipeline companies, local farms, and businesses, *were contacted regarding the chemicals they stored. Chemicals transported by barge, rail, _and highway were also addressed. For QtJad Ci ties, commodities transport~d on the Mississippi River; Chicago, -

Milwaukee, St. Paul, and Pacific Railroad; Chicago and North-western Railro.ad; U. s. Route 67, and Illinois State Road 84 were considered. In accordance with* Regulatory Guide 1. 78, only chemicals transported with a minimum shipment frequency of 10 per year by highway, 30 per year by rail, and 50 per year by barge were considered.

A survey of chemicals stored at, or transported to or from, fixed facilities was conducted by individually contacting each ~acility.

A listing of the firms contacted and associated potentially toxic chemicals is provided inTableC-2 of Appendix c.

A survey of barge traffic on the Mississippi River was performed using Reference 1 (Appendix C). This reference provides a record of yearly tonnage of a given commodity category shipped on a given section of the river. For this survey, the section from the mouth of the Missouri River to Minneapolis, Minnesota was used. Conservatively, all barge traffic into, out of, within, and through this section is assumed to pass by Quad Ci ties. *Ship-ment frequency was determine.a- by dividing the yearly tonnage

shipped by an average barge size of 2, 500 tons (Reference 2, Appendix C). * -

3-1

This methodology is conservative because it assumes only one barge per shipment, while normal shipments may contain as many as four barges (Reference 3.2). Table C-3 of Appendix C lists the

'chemicals whose shipment frequencies exceed 50 shipments per year.

Unlike the Reference 1 information on barge traffic, there is no centralized source of meaningful data on railway and highway commodity traffic which is applicable to this survey. Data on railway traffic was obtained by individually contacting each of the railroads discussed above. Data on highway commodity traffic was obtained by requesting information on chemicals transported to/from facilities within or near the 5-mile radius. This area includes chemical plants, bulk storage facilities, farms, and other chemical users/producers. While these sources cannot provide a complete listing of the regional highway traffic, they are .the only known source of information and therefore the only data available for evaluation. Tables C-4 and C-5 of Appendix C provide a listing of potentially toxic chemicals transported by railway and highway, respectively.

The results of the offiste survey analysis are provided in Section 3.5.

3.4 ANALYSIS METHODOLOGY The analysis of survey results was modeled to ,conform to Regu-latory Guide !. 78, which discusses the requirements and guide-lines to be used for determining the toxicity of chemicals in the control room following a postulated accident. The guidelines for .'***

determining the toxicity of a given chemical include shipment frequencies, distance from source .to site, and general properties of the chemical such as vapor pressure and toxicity limit.

Three types of standard limits are considered in defining hazardous concentrations. The first limit is the toxicity limit, which is the maximum concentration that can be tolerated for 2 minutes without physical incapacitation of an average hum~n.

If the toxicity limit is not available for a given chemical, a.

second* limit called the short-term exposure limit (STEL) is used.

STEL is defined as the maximum concentration to which workers can be exposed for 15 minutes without suffering from irritation, tissue damage, or narcosis leading to accident proneness or reduction of work efficiency. The third limit is the threshold limit value (TLV), defined as the concentration below which a worker may be exposed 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months a day, 5 days a week without adverse health effects

3-2

The models developed to calculate the concentration of toxic chemicals in the control room in the event of an accidental spill are consistent with the models described in NUREG 0570. These include a consideration of the following factors:

a. There i~ a failure of one container of toxic chemicals being shipped on a barge, tank car, or tank truck releasing all of.

its contents to the surroundings. Instantaneously, a puff of that fraction of the chemical which would flash to a gas at atmospheric pressure is released. The remaining chemical is assumed to spread uniformly on the ground and evaporate as a function of time due to the heat acquired from the sun, ground, and surroundings. Further, no losses of chemicals are assumed to occur as a result of absorption into the ground,_ cleanup operations, or chemical reactions.

b. From the geography of the area near Quad Cities, a spill from a railroad tank car is assumed to spread roughly over a circular area. Similarly, a spill occurring on the highways is also assumed _to spread over a circular area. * *

c. *The initial puff due to flashing, as well as the continuous plume due to evaporation, is transported and diluted by the wind to impact on the*.control room inlet *. The atmospheric dilution factors are calculated using the methodology of Regulatory Guide 1.78 and NUREG 0570, with partial building wake effects conservatively considered. *

d. To determine which chemicals need monitoring, the control room ventilation systems were assumed to continue nornial operation for the analysis. The chemic.al concentrations as a function of time were calculated and the maximum levels determined. These were compared to the toxicity limits.

Wherever the toxicity limits were not available, STEL values and TLVs. published by the American Conference of Govern-

. mental and Industrial Hygienists (ACGIH) were used in lieu.

of toxicity limits.

e. Concentrations were calculated as a function of time following the accident to compare with the published toxicity limits,**

STEL value~; and TLVs.

f. When the concentration in the control room did not exceed the toxicity limit. within 2 minutes after detection by odor, operator action to isol te the control room was assumed'~ In such cases,*monitors are not employed at the control room air intake. Where the toxicity limits are not available, STEL values are used in lieu of toxicity limits.

3-3

The control room ventilation system is designed as discussed

in Section 2.0. At present, there are no toxic chemical monitors installed to isolate the control room. Therefore, it was assumed that the ventilation system operates continu-ously at the design flowrates throughout the duration of the accident.

3.5 ONSITE/OFFSITE RESULTS The chemicals stored onsite are listed in Table C-1. Based on the physical and toxicological properties of these chemicals, it is concluded that .except for hydrochloric acid (HCl), none of the other onsi te stored chemicals are of concern. For .these other ~

chemicals, the unisolated control room concentration will not exceed the TLV in the event of a postulated release. Even though concentrations of HCl exceeded TLV, it was not considered necessary to monitor for HCl, based on the following. The odor threshold for HCl is 1 to 5 ppm. The operators can manually isolate the control room after detecting its odor. The rate of increase of concentration is such that after isolation, there would be sufficient time (greater than 2 minutes) for the

operators to put on breathing apparatus.

I The offsite chemicals that were considered were:

Chemicals stored at facilities

Chemicals transported in pipelines

Railroad traffic*

Barge traffic

Highway traffic

a. Chemicals Stored at*Facilities, Chemicals Transported in Pipelines, and Railroad Traffic*

These three categories. are considered as follows~ Each.of the chemicals was evaluated based on toxic, physical, and chemical properties. Some were eliminated based on Regula-tory Guide 1.78 (Table C-2) criteria. The remaining chemi-cals were analyzed assuming a fresh air intake of 2,000 cfm to the air handling system.and nq isolation. At this flow-rate, without isolation, the following chemicals exceeded the TLV and STEL in the control room: ammonia, chlorine, sulfur dioxide, benzene, hydrochloric acid, hydrofluoric acid, and riitric acid. These are discussed below

3-4

1) Ammonia

The odor threshold for this chemical is 50 ppm. The analysis showed that after sensing the odor, the operators would have less than 1 minute to manually isolate the control room and put on breathing apparatus before the concentration in the control room reached toxicity limit (100 ppm). Hence, it is recommended that it be monitored.

2) Chlorine The odor threshold for this chemical is 3.5 ppm. The analysis showed that the operators would have 35 seconds after sensin~ the presence of the chemical by odor to manually isolate the control room and put on breathing apparatus before the concentrations reached the toxicity limit (15 ppm). Hence, it is recommended that it should be mo'ni tored.

3) Sulfur Dioxide The odor threshold for this chemical is 3 ppm. The analysis showed that. the operators would have less than 1 minute after sensing the presence of the chemical by odor and manually isolating the control room and putting o~ breathing apparatus before the concentrations reached the toxicity limit.(20 ppm). Hence, it *is recommended that it should be monitored.

4) Hydrochloric Acid The analysis of the 1 imi ting case showed that the unisolated control room concentrations exceeded toxi-city limits. The odor threshold for HCl is 1 to 5 ppm and the concentration rise is such that there would be sufficient time for the operators to put on breathing apparatus after manual isolation before toxicity levels are reached in the control room.

5) Hydrofluoric Acid The odor threshold for this chemical is 0.036 ppm.

The analysis showed that the operators would have 110 seconds after sensing the presence of the chemical by odor to manually isolate the control room and put on breathing apparatus before the concentrations reached the toxicity limit (32 ppm}. Hence,. it is conclude*d that it need not be monitored

3-5

6) Nitric Acid The analysis showed that the unisolated control room concentrations rise slowly, and slightly exceed the TLV. ( 2 ppm) at 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months after the ace ident. This time period is judged long enough for the operators to

obtain information about the spill and manually isolate the control room. Moreover, the concentrations in the unisolated control room never exceed STEL ( 4 ppm).

Hence, it is concluded that it need not be monitored

3-Sa

b. Barge Traffic There are six categories of barge traffic: sodium hydroxide, alcohols, benzene and toluene, basic chemicals, nitrogeneous fertilizer, and other fertilizers. In the event of a release, the chemicals would flow into the water, mix well, and be diluted or be confined to the lower deck of the barge and be released at a slow rate. Some .chemicals are soluble in water and this would further decrease the release rate.

1) Sodium Hydroxide and Alcohols Sodium hydroxide and alcohols are chemicals whose boiling points are higher than ambient temperature.

Sodium hydroxide has negligible vapor pressure at room temperature; therefore, it does not need to be con-sidered. Alcohols are highly soluble in water. The odor threshold of alcohols is much lower than the TLV; therefore, they could be detected by smell and the control room could be manually isolated. The opera~

tors would have sufficient time to put on breathing apparatus before concentrations exceed the STEL in the control room.

2) Benzene and TOluene The analysis showed that the concentrations of toluene would not exceed TLV limits in the event of a release.

For benzene, the concentrations would exceed toxicity limits, but the odor threshold for benzene is lower than the TLV, and the concentration rise is slow enough to permit the operators to dete'ct it, manually isolate the control room, and put on breathing appara~

tus before toxicity levels are reached in the control room. Therefore, *benzene need not be monitored.

3) Basic. Chemicals This category is comprised of a large number of chemicals.

The published information does not "identify the chemicals by tonnage and number of shipments. The U.S *. Army Corps of Engineers (responsible for-compiling this data) was contacted to obtain the information on indi-vidual chemicals, and this information was not avail-able. Due to the large number of chemicals (toxic and nontoxic) involved, it is felt that the actual number of individual shipments for toxic chemicals would not exceed the shipment frequency for barges given in Regulatory Guide 1.78. Therefore, basic chemicals were not analyzed

3-6

4) Nitrogeneous and Other Fertilizers This is a broad category: most of the fertilizers are in solid form and are not toxic gases. Ammonia is included in this category. As discussed above for other chemicals, the release of such fertilizers would be confined to the lower deck of the barge, and a large fraction coming in contact with water would be dis-solved. Also, the offsite analysis of chemicals indi-cates that ammonia needs to be monitored, and therefore barge accidents involving ammonia are not specifically evaluated.

c. Highway Traffic Highway traffic was considered as discussed in Section 3.3 of this report

3-7

4.0 RADIOLOGICAL ANALYSIS General Design Criterion 19, Standard Review Plan (SRP) 6.4, and NUREG 0737, Item III.D.3.4 require that ad~quate radiation pro-tection exist to permit cont~ol room access an~ occupancy for the duration of a design basis ac~ident (OBA). The radiological analysis, provided in Appendix D,- considered the loss-of-coolant accident (LOCA) as the worst-case OBA and assumed main steam isolation valve (MSIV) leakage at technical specification limits.

Although several natural mechanisms exist to reduce or delay radioactive_ release to the environment, as discussed in Appen-dix D, credit was takeri only for iodine plateout on surfaces of the steam lines and condenser and radioactive decay prior to release. The analysis also assumed that the control room HVAC system was designed with the proposed modifications discussed in Section 5.3. A detailed discussion of the ~ethodology and assumptions of the analysis, as well as the conservatism of the approach, is included in Appendix o.

The following results are 30-day integrated doses in the control room based on the intake of unfiltered outside *air for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months following the LOCA, and filtered outsid~ air thereafter. The dose guidelines provided in SRP 6.4; Acceptance Criterion 8 are also provided for comparison purposes. ~he thyroid and skin doses consist of contributions from airborne radioactivity inside the control room. The whole-body dose consists of contributions from airborne radioactivity inside .and outside the control room, as well as direct shine from activity within the reactor-building above the refueling floor.

TOTAL CONTROL ROOM DOSES (Rem)

Thyroid Skin Whole-Body Quad Cities Units 1 and 2 13.07 2.46 0.211 SRP 6 *. 4, Guidelines for Control 30 30 5 Room

As evidenced by these results, the control room HVAC. system, with the design modifications discussed in Section 5.3, meets the radiological protection requirements of General Design Criter-ion 19 and SRP 6.4

4-1

5.0 PROPOSED HVAC DESIGN MODIFICATIONS 5.1 *OVERVIEW The following section presents proposed modifications to the existing control room HVAC system to meet the intent of NUREG 0737, Item III.D.3.4 and SRP 6.4, and to satisfy the requirements of General Design Criterion 19 regarding control room habitability following a radiological OBA. These modifi.cations include the addition of a redundant system (train B) consisting of an air handling unit (ABU), return air fan, chiller, pump, and assoc~

iated piping, ducts, dampers, and appurtenances, and an air filtration unit (AFU) common to both air handling systems.

5.2 EMERGENCY ZONE SRP 6.4 defines the boundaries for a control room emergency zone.

Within this zone, the plant operators are adequately protected.

against the effects of accidental radiological gas releases.

This zone also allows the control room to be maintained as the center from which emergency teams can safely operate in a design basis radiological release.

To satisfy this requirement, the following areas are included in the emergency zone.

a. Main control room, which includes all critical documents ~~d reference files

b. Cable spreading room

c. Auxiliary electrical equipment room

d. Computer room

e. New HVAC equiprnen t room, which houses .the new train B system Areas outside the emergency zone, which are normally serviced by the existing AHU system (train A), shall be isolated in emergen~y conditions *. Support rooms such as the kitchen, offices, and washrooms are accessible to operators with the aid of breathing equipment. The existing HVAC equipment room is also not included in the emergency zone

5-1

5. 3 PROPOSED MODIFICATIONS .

The proposed HVAC system design modifications are described below. Figure 1 provides a schematic of the proposed system.

a. Existing supply AHU train A, return air fan A, and all related dµctwork will be utiiized.

b. New su.pply AHU train B will be. located in a new HVAC equip-ment room. AHU train B will be sized to supply the emer-gency zone as discussed in Section 5.2. Ducts from new AHU train B will be connected to the corresponding ducts of the existing air handling system. A suggested possible arrange-ment is outlined in Figure 1.

c. New return air fan B will return air to new supply AHU train B. New AHU train B will also have outside air of 2, 000 cfm *.

d. A n'ew AFU, sized to accommodate 2,000 cfm, will be located in the new* HVAC equii;ment room. This unit will consist of a prefilter, electric beating coils, high-efficiency par-ticulate air (HEPA) filter, charcoal filters, HEPA filter, and two full-capacity fans. The AFU will be in compliance with Regulatory Guiqe 1. 5.2.

e. A new 100%-capacity chilled water system for train B wilL be installed in the new HVAC equii;ment room.

f. Bubbletight and low-leakage dampers will be U:sed as shown in Figure 1.

5.4 MODIFIED SYSTEM OPERATION For normal conditions, the AHU train A system will operate as discussed.in Section 2.0.

For an emergency condition, as determined by radiation monitors in the.reactor building ventilation manifold, system operation will be as follows. The bubbletight isolation dampers will automatically isolate the normal outside air intake to the AHUs and all ventilation zones which are not mentioned in Section. 5. 2 above.

Within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the outside air damper to the new AFU will be remote manually opened and_ an AFU fan will beg in supplying

filtered air to one AHU train. The return air fan will route the return air to the associated AHU train. Barring component failures in the operating AHU train; the system will continue to operate in this manner for the duration of the emergency.

5-2

On failure of airflow in the operating AHU train system, that train 'is automatically isolated and the redundant train is ener-gized. outside air will be supplied to the redundant AHU train by an AFU fan in this operating mode. The return air fan will route the return air to the associated AHU.

In the event that toxic gases are detected as discussed in Section 3.5 of this report, all outside air intakes and all ventilation zones which are not mentioned in Section 5.2 will be isolated. The AHU will supply 100% recirculated air to the emergency zone.

5-3

6.0 RECOMMENDATIONS

Based on the results of the radiological analysis, it is recom-

mended that the control building HVAC system design incorporate the modifications discussed in Section 5.3.

Based on the results of the toxic gas analyses, it is re_comrnended that monitors be added to the fresh air intake to detect ammonia, chlorine, and sulfur dioxide.

The system should incorporate automatic isolation of the fresh air intake upon detection of any of the above toxic gases.

I 6-1

R.E. 1 QUA.D CITIE.5 CONTROL. RM HVAC. 5C EMATIC

~Vl&IOIJ: 0 I OAT'- : tfi,A!ll 117/IZ/91

~Cit'\

(O)

~..,

rpt.JT!i?.O\, 1ZOOM *

~v.

B,700 CFH

(.1i;,">>o) 11u'-o" E.Y.Rl:t r

~

es g

~ E

~

a.c.v. <.~'-o"

.t." ~J I IJ

. ~ I! ~ t 11r.o CU'f'o!OI.

=....+- _____,

11 r AllZ. 1" i&: U:.

~

f IZOOCl'M (Joaoc.FH)

If

~s UJ l:

...,i .%

~ !!' (,/'°°)

. (/Z.t.0) 3 J:

cu....,, )

~

"""'*p; s II&

_, 2375 CR1 I~

!OOOC.FM g+..E?TIUC... e.ovrr'l-ff!'~T z~.i.50 CrH e8 ~H 41(.100 Cl"M eLLY 5"S'*o*

l - - - l i - . - ( S-200) cot'f'V!&!l :

~

aev ~**o'*

5/oOO CFH 9*

)

it>llte ""~ "u~1blt.~

NMo , Cl, "JOa

~~~~~~:..~~

"IP-I~~~

.,... t37'S C.Fl"I

( ft,75 )

ExFILT.

tWeeLL ~~T 1Wo'lf:'Ee* c.ot.JTR.ol. t:!il.>tl...DllJCo EMIE..llC,E.IJC."f ZOIJE

APPENDIX A NUREG 0737, ITEM III.D.3.4 CONTROL ROOM HABITABILITY REQUIREMENTS

III.D.3.4 CONTROL-ROOM HABITABILITY REQUIREMENTS Position In accordance with Task Action Plan ftem III.D.3.4 and control room habitability, licensees shall assure that control room operators will be adequately protected against the effects of 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 (Criterion 19, *control Room.* of Appendix A. *General Design Criteria for Nuclear Power Plants,* to 10 CFR Part SO).

Changes to Previous Requirements and Guidance There are no changes to the previous requirements.

Cl arf f i cation (1) .All licensees *ust .. ke a subllittal to the NRC regardless of whether or not they 11et the criteria of the referenced Standard Review Plans'(SRP) sections. The new clarification specifies that licensees that 111et the criteria of the SRPs should*provfde the basis for their conclusion that SRP 6.4 requirements are *et. Licensees 91y establish this basis by referencing past submittals to the NRC and/or providing new or additional f nfonnation to supplement past subllitt.ls.

(2) All licensees with control rooms that 1ttet the criteria of the following sections of the Standard Review Plan:

2.2.1-2.2.2 Identification of Potential Hazards in Site Vicinity 2.2.3 Evaluation of Potential Accidents; 6.4 Habitability Systems shall report their findings regarding the specific SRP sections as explain~d below. The following documents should be used for guidance:

(a) Regulatory Guide 1.78, *Assumptions for Evaluating the Habitability of Regul1tory Power Plant Contr0l Room During a Postulated Hazardous Chemical Releaseu; (b) Regulatory Gufde 1.95, *protection of Nuclear Power Plant Control*

Room Ope.rators Against an Accident Chlorine Release"; and, (c) K. G. Murphy and K. M. Caiape, ~Nuclear Power Plant Control Roo~

J Ventflatfon System Design for Meeting General Design Criterion 19,"

13th AEC Afr Cleaning Conference, August 1974.

Licensees shall submit the results of their findings as well as the basis for those findings by January 1, 1981. In providing the basis for the habitability finding, licensees 91y reference their past submittals.

Licensees *should, however, ensure that these submittals reflect the current"f1cflity design and that the information requested in Attachment 1 h provided.

III. D. 3. 4-1 3-197

003234 (3) All licensees with control rooais that do not meet the criteria of the

bove-listed references, Standard Review Plans, Regulatory Guides, and other references.

These licensees shall perform the necessary evaluat;ons and identify appropriate 1K>dificatfons.

Each licensee submittal shall include the results of the analyses of control room concentrations from postulated accidental release of toxic gases and control room operator radiation exposures from airborne radioactive *aterial and direct radiation resulting from design-basis accidents. The toxic gas accident analysis should be performed for all potential hazardous chemical releases occurring either on the site or within 5 miles of the plant-site boundary. Regulatory Guide 1.78 lists the chemicals most commonly encountered in the evaluation of control *room habitability but is not all inclusive.

The design-basis-accident (DBA) radiation source term should be for the loss-of-coolant accident LOCA containment leakage and engineered safety feature CESF) leakage contribution outside containment as described in Appendix A and 8 of Standard Review Plan Chapter 15.6.5. In addition, boiling-water reactor (BWR) facility evaluations should add any leakage from the main steam isolation valves (MSIV) (i. e., valve-stem leakage, valve seat leakage, main steam isolation valve leakage control system release) to the containment leakage and ESF leakage following a LOCA. This should not be construed as altering the staff recoanendatfons in Section D of Regulatory Guide 1.96 (Rev. 2) regarding MSIV leakage-control systems. Other DBAs should be reviewed to determine whether they *ight constitute a more-severe control-room hazard than the LOCA.

In addition to the accident-analysis results, which should either identify the possible need for control-room 1tOdifications or provide assurance that the habi*tability systems will operate under all postulated conditions to permit the control-room operators to remain in the control room to take appropriate actions required by General Design Criterion 19, the licensee should submit sufficient information needed for an independ~nt evaluation of the adequacy of the habitability systems. Attachment 1 lists the information that should be provided along with the licensee's evaluation.

Applicability This requirement applies to all operating reactors and operating license applicants.

Implementation Licensees shall submit their responses to this request on or before January-1, 1981. Applicants for operating licens's shall submit their responses prior to issuance of a full-power license. Modifications needed for compliance with the control-room habitability requirements specified in this letter should be identified, and a schedule for completion of the modifications should be provided. Implementation of such aodific1tions should be started without awaiting the results of the staff review. Additional needed modifications, if any, identified by the staff during its review will be specified to licensees 3-198 . III.D.3.4-2

Type of Review

A postimplecnentation review will be perforeed.

Documentation Required By January 1, 1981 licensees shall provide the information described in Attachment 1. Applicants for an operating license shall submit their responses prior to full-power licensing.

Technical Specification Changes Required Changes to technical specifications will be required.

References NUREG-0660, Item III.D.3.4.

Letter from D. G. Eisenhut, NRC, to All Operating Reactor licensees, dated May 7, 1980.

III. D. 3.-4-3 3-199

~-

003234 111.D.3.4, ATTACHMENT 1, INFORMATION REQUIRED FOR CONTROL-ROOM

(1)

HABITABILITY EVALUATION Control-room mode of operation, i.e.,. pressurization and filter recirculation for radiological accident isolation or chlorine release (2) Control-room characteristics (a) air volUllle control room (b) control-room emergency zone (control room, critical files, kitchen.

washroom, computer room, etc.)

(c) control-room ventilation system schematic with normal and. emergency air-flow rates (d) infiltration leakage rate (e) high efficiency particulate air (HEPA) filter and charcoal adsorber efficiencies (f) closest distance between containment and air intake (g) layout of control room, air. intakes,* containment building. and chlorine, or other chemical storage f~cility with di11ensions

.(h) control-room shielding including radiation streaming from penetrations, doors, ducts, stairways, etc.

(i) automatic isolation capability-d&111per closing time. damper leakage*

and area (j) chlorine detectors or toxic gas (local or f'elllote)

(k) self-contained breathing apparatus availab11ity (number.)

(1). bottled air supply (hours supply)

(11) 1111ergency food and potable water supply (how 11any days and how 111any people) *

(n) control-room personnel capacity (noMDal and emergency)

(o) potassium fodf de drug supply (3) Onsite storage of chlorine and other hazardous chemicals (a) total aaount and size of container (b) closest distance from control-room air intake

3-200 III.D.3.4-4

003234

(4) Offsite *anufacturing, storage, or transportation facilities of hazardous chemicals (a) identify facilities within a 5-mile radius; (b) distance from control room (c) quantity of hazardous chemicals in one container (d) frequency of hazardous chemical transportation traffic (truck, rail, and barge)

(S) Te~hnical specifications (refer to standard technical specifications)

(a) chlorine detection system (b) control-room eaergency filtration system including the capability to maintnin the control-room pressurization at 118-in. water gauge, verification of isolation by test signals and damper closure times, and filter testing requirements ..

3-201 III.0.3.4-5

APPENDIX B NRC-REQUESTED INFORMATION REQUIRED FOR CONTROL ROOM HABITABILITY EVALUATION

The following list of responses corresponds directly to the items requested by Attachment 1 to NUREG 0737, Item III.D.3.4. The responses reflect the modified control room HVAC system design as discussed in Section 5.3 of this report.

Item Response

,. 1 Upon detection of high airborne radioactivity in the reactor building ventilation manifold, the control room HVAC system will enter the emergency mode of operation. In this mode, normal makeup and selected return air ducting are automati-cally isolated. Within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the control room emergency zone is pressurized by once-through makeup air passing through an emergency filter unit.

Upon detection of high ammonia, chlorine, or sulfur dio,x ide concentrations in the control room HVAC fresh air intake, the system will automatically be switched to the isolation/

recirculation mode of operation. In this inode, the operators will put on breathing apparatus until the toxic chemical

,concentrations are reduced to below safe levels.

Upon operator detection of benzene and hydrochloric acid, the system will be manually placed in the isolation/recir-culation mode of operation. In this mode of operation, the operators will put on breathing apparatus until the toxic chemical concentrations are reduced to below detectable levels.

2 Control Room Characteristics

a. Control room air volwt1e: The air volwt1e of the control room emergency zone is approximately 184,000 cubic feet, including 58,000 cubic feet for the main control*

room.

_..b. Control room emergency zone: The control room emer-gency zone includes the main control room, cable

~preading room, computer room, auxiliary electrical equipnent room1 and the new HVAC equipment room.

c. Control. room ventilation system schematic: Figure 1 of this report provides a proposed ventilation system schematic for the control room emergency zone indi-cating normal and emergency airflows *

B-1

d. Infiltration leakage rate: Infiltration leakage into the control .room is negligible because the control room will be maintained at a positive pressure with respect to adjacent rooms during both normal and emergency conditions. For emergency conditions, makeup air will be limited to a maximum of 2,000 scfm. Backflow infiltration is assumed to be 10 scfrn.

During isolation/recirculation conditions, infiltration is initially negligible because the control room will be at a positive pressure at the time of system iso-lation. Infiltration following isolation is conserva-tively assumed to be 105 cfrn following system isolation.

e. HEPA filter and charcoal adsorber efficiencies: The HEPA filters in the emergency filtration train are rated at 99.97% efficiency in removing particulates of 0.3-micron size and larger. The charcoal filters in the emergency filtration train are rated at 99% effi-ciency for .re~oval of elemental and organic iodine.

f. Closest distance between containment and air intake:

The control room HVAC system intake (elevation 633')

is located approximately 232 feet from the closest wall of the secondary containment reactor building. Addi-tionally, the standby gas treatment system (SGTS) exhaust to the main chimney is located approximately 520 feet laterally and 272 feet above the HVAC system intake.

g. Layout: A layout drawing showing the relative location I

of the control room, HVAC system intake, toxic gas moni-tors; turbine building, main chimney, and the contain-ment is shown in attached Figure B-1.

h. Control room shielding: The control room design con-sists of poured-in-place reinforced concrete with 6-inch floor and ceiling slabs and 18- to 27-inch walls. The radiation streaming effect in the control r6om is

,considered negligible during normal operation and provides a 30-day integrated whole-body dose of 57 *mRem post-LOCA. Refer to FSAR Section 12.3 for further details.

i. Automatic isolation capability, damper information:

Isolation of the normal makeup air intake takes approxi-mately 20 seconds. The makeup air intake and exhaust dampers will be bubbletight with an area of 25 sq~are feet each and a leakage factor of zero. Office zone 10" x 10" duct and HVAC equipment room zone 18" x 10" duct will be.isolated with bubbletight dampers with a leakage factor of zero for the return air, and a low leakage type damper for the supply air *

8-2

Item Response

j. Chlorine or toxic gas detectors: Toxic gas detectors will be provided for ammonia, chlorine, and sulfur dio-xide. The sensitivity of the ammonia detector will be 125 ppm with a response time of 10 seconds. The sensi-tivity of the chlorine detector will be 5 ppm with a response time of 10 seconds. _The sensitivity of the sulfur dioxide detector will be 5 ppm with a response time of 10 seconds.

k, Self-contained breathing apparatus availability and

1. bottled air supply: Five self-contained breathing apparatus are available in the control room, each with a 20-minute air supply. A manifolded bottled air system is also available. The system is capable of supplying air to five people for 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

m. Emergency food and potable water supply: The control n.

room does not presently contain food prov1s1ons.

_Adequate water is available near the control room.

Control room personnel capacity: Durin_g normal oper-I ation, the control room will contain .four people. In emergency conditions, the personnel capacity will be limited to five people by the bottled air system capabilities.

3

-o. Potassium iodide supply: A supply of 1;000 130-milli-gram doses of potassium iodide i$ available in the osc.

Onsite Storage of Chlorine and Other Hazardous Chemicals I

Refer to Table C-1 of Appendix C for this information. .......

4 Offsite Manufacturing, Storage, or Transportation Facilities of Hazardous Chemicals Re fer to Tables C-2 through c~s of Append ix C for this information.

5 Technical Specifications

a. Chlorine detection system: Because no chlorine detec-tion system exists at the present time, no technical specification has been written for it. The technical specifications will be reviewed and revised, as necessary, to address the proposed modifications. * **

b. Control room emergency filtration system: Because no control room emergency filtration system exists at the present time, no technical specification has been written for it. The technical specifications will be reviewed and revised, as necessary, to address the proposed modifications.

B-3

484'-0 '

5GTS. VENT STACK NOTE: THE ST~UC7U~E TO MOUSE Tl-'E I

PF:.OPOSED b

_, ~ERVICE BLOG.

C.ONTTWL 8UILDll.JGi

?() UVAC SYSTEM

ww.e1~lll!.

MODIFICATIONS TURBINE BLDG. WILL &E SMOWN AT A LA.TER DATE.

CONTROL ROOM EXIST ING. IWAC EQUIP. ROOM___/

$********(+/-;

REACTOR BLDG.

c30' -0" l'U.VISI0"-1' 1 r;>io.TE. 10*12*&1 GUAD C *1r1 ES CONTROL ROOM HABITABILITY GENERAL PLANT LAYOUT" F/Gt URE B- I I.JOT TO SCALE

APPENDIX C

SUMMARY

OF OFFSITE TOXIC CHEMICAL SURVEY

TABLE C-1

Acetylene POTENTIALLY TOXIC CHEMICALS STORED WITHIN THE Chemical QUAD CITIES SITE BOUNDARY Quantity(!)

100 ft 3 <2 >

Location Gas bottle storage rack< 4 >

Argon 330 ft 3 <2 > Gas bottle storage rack< 4 >

Carbon dioxide so lb Gas bottle storage rack< 4 >

Ethylene diamene 6 ,000 gal. South of offgas filter tetra-acetic acid building Helium 242 f t 3 ( 2 ) Gas bottle storage rack< 4 >

Hydrochloric acid 1,000 gal. Crib house Hydrogen 194 f t 3 ( 2 ) Gas bottle storage rack< 4 >

Hydrogen 2,100 ft 3 <3 > In yard west of heater boiler building Nitrogen 22*4 ft 3 ( 2 ) Gas bottle storage rack< 4 >

P-10 (methane-argon 200 f t 3 ( 2 ) Gas bottle storage rack< 4 >

mixture)

sodium chlorite 5, 000 gal. South of offgas filter building Sodium hydroxide 4, 000 gal. Turbine building 1 Sodium hypochlorite 35,000 gal. North of crib'house Sulfuric acid 2; 000 gal. Turbine building 1

(!)Wherever multiple containers of the same chemical are stored in close proximity, the quantity of the largest container.is

provided.

~~~Standard type gas bottles Hydrogen at 70F,* 2,640 psi

<4 >Located on south wall of service building

TABLE C-2 POTENTIALLY TOXIC CHEMICALS STORED AT FIXED FACILITIES WITHIN A 5-MILE RADIUS OF QUAD CITIES(l)

Facility C.F. Industries Distance (miles) 3.10 Chemical Anhydrous ammonia Quantity< 3 , 5 >

20,000 tons Comanche Wastewater 4.00 Chlorine 150 lb< 4 >

Treatment Dorne Pipeline (pipe- 3.00 Ethane 12< 5 >

line) 3.00 Ethylene 12< 5 >

3.00 Propane 12< 5 >

Hydroc.arbon Trans- 1.90 Ammonium nitrate (28%) 1,000,000 gal.

portation Iowa-Illinois Gas and 1.00 Natural gas Electric (pipeline) 1.00 Natural gas Interstate Power 4.90 Natural gas (pipeline) .

Johnson Manufacturing 3.60

Muriatic acid a,ooo gal.

Propane 1,000 gal.

Mid-America Pipeline 3.00 Ethane/propane (70%/ 10< 5 >

(pipeline) 30%)

3-M Company Alkanes 1, 000*, 000 lb .

Ammonia 250,000 lb Chlorine 2,000 lb Cyclohexarnines 150,000 lb

. Fluorinated organit 250,000 lb Halogenated organic 250,000 lb Hydrofluoric aqid 120 '000. lb Ke tones 300,000 lb Organic isocyanate 200, ooo* lb Williams Pipeline 3.30 LP gas 12 (pipeline)

(l)Includes pipelines.

<2 >This list includes only those facilities with potentially toxic chemicals, or those from which no information was received.

<3 >wherever multiple containers of the same chemical are stored at the same facility, th~ quantity of the larger. container is provided.

<4 >standard type gas bottles.

<5 >ouantities for p~pelines are expressed as pipe diameter (inches).

TABLE C-3 POTENTIALLY TOXIC CHEMICALS T~NSPORTED ON BARGES WITHIN A 57~fLE RADIUS

OF QUAD CITIES Chemical Category( 2 ) Yearly Shipment (tons )i Alcohols 375,945 Basic chemicals 2,087,975 Benzene and toluene 165,739 Nitrogenous fertilizers 1,113,720 Other fertilizers 1,061,097 Sodium hydroxide 431,942 (l)Data 'is based on b~rge traffic along the Mississippi River, from the mouth of the Missouri River to Minneapolis, Minnesota, o.ss mile from the Quad Cities site. The source of the information is Waterborne Commerce of the u. s.,

U.S. Army Corps of Engineers, 1978 (latest edition).

2

( ) The chemical categories 1 isted above. are those which were determined to pass by the Quad Cities site with a minimum frequency of 50 times. per year. Shipment frequencies were calculated using a 2,500-toti barge capacity.

TABLE C-4 POTENTIALLY TOXIC CHEMICALS TRANSPORTED ON RAILROADS WITHIN A 5-MILE RADIUS OF QUAD CITIES(l, 3 )

Distance Quantity (per Railroad (miles) Chemical Container)

Chicago, Milwaukee, 0.70 Chlorine 18, 100 gal.

St. Paul, and Pacific Phosphatic 14,500 gal.

fertilizer Sulfur 11, 000 gal.

dioxide Transported* on the .7 Alkanes 140,000 lb Chicago, Milwaukee, Hydrofluoric 80,000 lb St. Paul, and Pac*ific *acid by 3

M Company Chicago-Northwestern< 2 > 4.95 Anhydrous *30,000 gal.

ammonia LP gas

30~000 gal.

Transported on the 4.95 Ethylene 130,000 lb Chicago-Northwestern Isobutane 30,000 liquid gal.

by Chemplex Company *Propylene 30, 000 gal.

Mixed C4 30,000 gal.

hydrocarbons

Transported on the 4.95 Aqua ammonia 50 tons Chicago-Northwestern 83% ammonium so tons by Hawkeye Chemical nitrate solution Nonpressure so tons nitrogen Prilled 93 tons ammonium nitrate

(!)The chemicals listed above pass by the Quad Cities site with a minimum frequency of 30 times per year.

<2 >The Chicago-Northwestern Railroad indicated that its records were not sufficient td provide an inclusive list of the toxic chemicals it transports with a minimum frequency of 30 time.s per year.

<3 >The Davenport, Rock Island, and Northwestern Railroad operates a line through the Quad Cities 5-mile radius; however, no toxic chemicals are shipped on it

TABLE C-5 POTENTIALLY TOXIC CHEMICALS TRANSPORTED ( l)

ON HIGHWAYS WITHIN A 5-MILE RADIUS OF QUAD CITIES Distanf2 Highway (miles) ) Chemical Quantity< 3 >

Illinois .10 Anhydrous ammonia 20 tons State 28% Ammonium nitrate 24 tons Route 84 Chlorine 1 ton Cyclohexamines 20 tons Ke tones 20 tons Liquid halogenated organic 20 tons Organic isocyanate 20 tons Sulfuric acid 45,500 lb u.s. 2.40. Anhydrous ammonia 18 tons Route 67 Aqua ammonia 23 tons (in Iowa) Carbon dioxide 18 tons Ethyl alcohol SS gal.

Ethylenedyamine SS gal.

aydrobromic acid 48% SS gal.

Isopropyl alcohol SS gal.

Muriatic acid lS gal.

Nitric acid 23 tons Nonpressure nitrogen 23 tons Prilled ammonium nitrate 23 tons Sodium hydroxide 45,500 tons SO or 70% Urea 23 tons 3.60 *Propane 4, 000 gal.

Muriatic acid *4,000 gal.

(l)The chemicals listed above pass by the. Quad Cities site with a minimum frequency of 10 times per year. Refer to Section 3 of this report for further discussion of this subject.

<2 >c1osest potential approach of the transport vehicle to the Quad Cities site.

<3 >wherever multiple container sizes of the same chemical are transported, the quantity of the largest container is provided

TABLE C-6 REFERENCES

1. Waterborne Commerce of the United States, 1978, U.S. Army Corps of Engineers

2. Telephone conversation between B. Burdick and R. MacLauchlin, U.S. Army Corps of Engineers, September 14, 1981 (3320) 3.* Telephone conversation between B. Burdick and D. Christensen, Bogott Industries, September 30, 1981 (3428)

4. Telephone conversation between B. Burdick and J. Kissane, Air Prod u_cts, Sept~mber 30, 1981 ( 3430)

s. Telephone conversation between B. Burdick and J. Davis, Liquid Air, October 1, 1981 (3429)

6. Telephone conversation between D. Semon and D. Wheelan, Alpha Crush Stone, July 27, 1981 ( 3054)

7. Telephone conversation between D. Semon and R. Hawk, Whiteside Farm Service, July 28, 1981 (3053)

8.

9.

Telephone conversation between D. Semon and W. vanZudien, C.F. Industries, July 28, 1981, August 3, 1981 (3058, 3077)

Telephone conversation between D. Semon and R. _Alm, Comanche Wastewater Facility, August 4, 1981 (3087)

10. Telephone conversation* between D. Semon and R. Geerts, Hydrocarbon Transportation, August 4, 1981 (3091)

11. *Telephone conversation between* D. Semon and J. Hany,.

Growmark Incorporated, August 7, 1981 (3116)

12. Telephone conversation between D. Semon and A. Schulz, Princeton Wastewater Facility, August 7, 1981 (3118)

13. Telephone conversation between D. Semon and N. Griffith, Griffith Oil, August 10, 1981 (3126)

14. Letter from Hawkeye Chemical, August 20, 1981 (3211)

15. Telephone conversation between D. Semon and M. White, Hawkeye Chemical, July 27, 1981 (3055)

16. Telephone conversation between o. Semon and B. ~imz, Princeton Marina, August 11, 1981 (3142)

17. Telephone conversation between B. Burdick and J. Nalevanko, Materials Transportation Bureau, Department of Transpor-tation, August 12, 1981 (3151)

18. Telephone conversation between D. Semon and J. vermazen, Bennett Explosives, August 13, 1981 (3156)

19. Telephone conversation between D. Semon and K. Kalarhar, Interstate Pipeline, August 21, 1981, August 7, 1981, September 28, 1981 (3206, 3117, 3440)

20. Telephone conversation between o. Semon and L. Arson, Dome Pipeline, August 6, 1981 ~ September 28, 1981 ( 3090, 3438)

21. -Telephone conversation -between D. Semon and J. Dill, Dome Pipeline, August 21, 1981 (3207)

22. Telephone conversation between o. Semon and A. Bieienberg, Iowa-Illinois Gas & Electric., August 24, 1981, September 28, 1981 (3226, 3439)

23. Telephone conversation between D. Semon and o. Berry, William Brothers Pipeline, August 10, 1981, August 24, 1981, October 1, 1981, September 30, 1981 (3135, 3224, 3245, 3423)

24. Telephone conversation between D. Semon and M. White*,

Hawkeye Chemical, August 28, 1981 (3232)

25. Letter from Hawkeye Chemical, August 20, 1981 (3211)

26. *Letter from Johnson Manufacturing, August 28, 1981 ( 3233)

27. Telephone conversation between .D. Semon and M. Young, Mid-America Pipeline, August 10, 1981, September 14, 1981,

.October 2, 1981 (3124, 3346, 3518)

28. Telephone conversation between D. Semon and R. Thompson,

. Johnson Manufacturing, September 14, 1981 (3345)

29. Letter from Chemplex, October 1, 1981 (3432) *

30. Telephone conversation between D. Semon and R. Schuler, Chemplex, October 26, 1981 (3526)

31. Telephone conversation between B. Burdick and T. Baltutis,.

3-M, October 13, 1981 (3479)

32. Letter from 3-M, October 13, 1981 (3484)

33.

34.

35.

Telephone conversation between D. Semon and J. Mendelbaum, U.S. Interstate Commerce Commission, August 19, 1981 (3188)

Letter from Chicago, Milwaukee, St. Paul, and Pacific Rail-road, August 26, 1981 (3239)

Telephone conversation between B. Burdick and R. Ridel, Chicago, Milwaukee, St. Paul, and Pacific Railroad, Sept~rnber 3, 1981 (3260)

36. Telephone conversation between B. Burdick and w. Bruce, Chicago and Northwestern Railroad, August 3, 1981 (3149)

37. Telephone, conversation between D. Semon and w. Bruce, .

Chicago and Northwestern Railroad, August 18, 1981 (3182)

38. _Telephone conversation between D. *Varner* and Betty Mc-Bride, Davenport, Roc.k Island, and Northwestern Railroad, July 2, 1981 (2921)

APPENDIX D RADIOLOGICAL ANALYSI.S FOR CONTROL ROOM HABITABILITY FOLLOWING A DBA-LOCA

.'\

A. INTRODUCTION The following analysis was performed in accordance with the guidance of NUREG 0737, Item III.D.3.4 to determine compliance with the radiological requirements of General Design Criterion 19 and Standard Review Plan (SRP) 6.4. The loss-of-coolant accident (LOCA) was considered in the analysis to be the radiological design basis accident (DBA). Furthermore, main steam isolation valve (MSIV) leakage at the technical specification limit was asst.nned for the analysis.

The results of this analysis are considered conservative.

Several natural mechanisms will reduce or delay the radioactivity prior to release to the environment. However, credit was taken only for iodine plateout on surfaces of the steam lines and condenser and radioactive decay prior to release. These mechanisms are discussed in Section E.

B. METHODOLOGY The guidelines given in SRP 6.4 (Reference 1) and Regulatory Guide 1.3 (Reference 2) have been used with the exception of the X/Q for the control room and plateout of iodines during trans-portation within pipes. Realistically, the components of main steam lines and the turbine-condenser complex, though nonsafety grade, would remain intact following a DBA-LOCA. Therefore, plateout of iodines on surfaces of main steam lines and the

turbine-condenser complex is expected. Atmospheric dispersion factors are based on the Halitsky Methodology from Meteorology and Atomic Energy 1968, as di~cussed in Section D.

C. ASSUMPTIONS AND BASES Regulatory Guide 1.3 has been used to determine activity levels in the containment following a DBA-LOCA. Activity releases are based on a containment leakage rate of 0.75% per day. Table D-1 lists the assumptions and parameters used in the analysis and dose poin~ locations. The majority of the containment leakage I

will be collected in the reactor building and exhausted to the atmosphere through the 99% efficient SGTS filters as an elevated release from the.main stack. However, there are certain release pathways from the containment which will bypass the SGTS filters.

The bypass leakage has been quantified by assuming that all MSIVs leak at the technical !;pecification limit of 11.5. scfh per main steam line. Based on this assumption, a total leakage for all steam lines together would be 46 scfh (0.7667 scfm).

D-1

Radioactivity leaking past the isolation valves could be released through the outboard MSIV sterns into the steam turinel, or con-tinue down the steam lines to the stop valves and into the turbine-condenser complex. Leakage into the steam tunnel is exhausted by the SGTS filtration system, thus eliminating it as a bypass pathway. Leakage down the steam lines is subject to '

plateout and delay within the lines. Reference 3, Section s.1.2 discusses iodine removal rates which can be applied to calculate plateout on the piping and turbine condenser surfaces. Elementai and particulate iodine decontamination factors of over 100 can be calculated for small travel distances and large travel times down the steam lines, considering the small volumes of leakage which leak past the valves.

The credit for plateout and holdup within steam lines and the turbine-condenser complex has been taken by dividing them into three different volumes. The first volume consists of steam

lines between the inboard and outboard i.solation valves! the second volume consists of steam lines between the outboard iso-lation valves and the turbine stop valves, and the third volume includes the steam lines after the turbine stop valves and the.

turbine-condenser volume complex. Conservatively, failure* of an.

inboard isolation valve in one main steam line has been consi-dered. The activity leaking from the primary containment travels through, and mixes well within, each volume prior to release to the environment from the turbine-condenser complex. The removal rate for iodine due to plateout within each volume is based on the estimated surface area and the methodology given in Refer-ence 3, Section s.1.2. These removal rates are only applied to elemental and particulate iodines. The removal of organic iodine through plateout is not considered. It was assumed that the bypass leakage is collected in the steam line turbine-condenser*

volume complex from which it will leak at 1% of the turb.ine-condenser volume per day. This leak rate is consistent with the assumptions used for the control rod drop accident in SRP 15.4.9 (Reference 4.). This assumption is conservative, because the volumetric leakage out of the condenser would be approximately the same as the inleakage and the 1% leak rate per day out of the turbine-condenser volume is higher than the leak rate into the steam* lines from the drywell ~ Furthermore, the bypass leakage will be cooling and condensing as it travels down the lines.

Leakage within the turbine building would be exhausted by the heating, ventilating, and air conditioning (HVAC) system if it were working. Additional plateout on ductwork, fans, and unit coolers would further minimize the iodine releases. Should the HVAC system not be working, then any bypass leakage would tend to collect in the building and be subject to additional decay and plateout. Leakage from the turbine building into the control room is minimized by the separate HVAC systems and by maintaining the interconnecting doors in their normally closed positions.

Ir2

The control room pressurization system ensures that leakage is from the protected area towards the other parts of the building, further minimizing the possibility of contaminating the protected I

areas. A positive pressure is maintained in the main control room by introducing 2,000 cfm of outside air through a 99% effi-cient filtration system.

The activity which enters the main control room may be the result of bypass leakage, standby gas treatment system (SGTS) exhaust in the outside air, or both,* depending on wind direction. Because of the locations of these sources with respec~ to the control room HVAC intake, it is possible for the intake to be exposed to activity from both sources at the same time. Because the SGTS exhaust is elevated, the concentrations from this source at the intake will be less than those due to bypass leakage. This analysis conservatively assumes that the activity concentration at the intake is due to concurrent bypass leakage and chimney rele~ses for the_duration of the event.

D. ATMOSPHERIC DISPERSION FACTOR (X/Q)

I The following discussion is an explanation of the reasons for the use of the Halitsky X/Q methodology and a value of K = 2, instead

of the Murphy methodology (Reference 5) which SRP 6.i suggests as an interim position.

Historically, the preliminary work on building wake X/Q's was based on a series of wind tunnel tests by J. Halitsky, et al.

Halitsky summarized these results in Meteorology and Atomic Energy in 1968 (Reference 6). In 1974, K. Murphy and K. Campe of the *":***.

NRC published their paper based on a survey of existing data.

This X/Q methodology, which presented equations without derivation or justification, was adopted as the interim methodology in SRP 6.4 in 1975. Since then, a series*of actual building wake X/Q measurements have been conducted at Rancho-Seco (Reference 7) and several other papers have been published documenting the resu~ts of additional wind tunnel tests.

In Reference S, Murphy suggested the following equation for t;he calculation df X/Q X/Q = Kc/AU where K

c =K+ 2 K = 3/( S/d) 1. 4 A = Cross-sectional ~rea of the building u = Wind speed D-3

This formulation was derived from the Halitsky data in Figure 37 of Reference 5 from Murphy's paper. The Halitsky data were from wind tunnel tests on a model of the EBR-II rounded (PWR type) containment and the validity of the data was limited to 0.5<s/d <3 (Reference 6, Section 5.5.5.2). The origin and reason for the +2 in K + 2 is not known. All other formulations use K only, and for the situation where K is less than 1, the use of K + 2 imposes an unrealistic limit on the X/Q.

For the Quad Cities plant, the building complex is composed of square-edged buildings and not a round-topped cylindrical con-tainment as was used in the Halitsky experiments. For an HVAC intake located near the south wall of the control room at ele-vation 633'-0", the intake will be subject to a building wake caused by a combination of the reactor building and the turbine building for any bypass leakage escaping from the turbine building. There will be no reactor building bypass leakage because the building is kept at a negative pressure by the SGTS which exhausts to the main chimney.

Because the Murphy methodology could not be applied, a survey I

of the literature was undertaken. It was found that the Halitsky wind tunnel test data (Reference 6, Section 5.5.5) conservatively overestimated K values *by factors of up to possibly lo.* Given this conservati~m, it was felt that the use of a reasonable K value from the Halitsky data on square-edged buildings shouldc be acceptable. A review of Figure 5.27 from M&AE (Reference 6) resulted in K values in the 0.5 to 2 range. A value of K = 2 was chosen tocget a X/Q f~r the control room. A building 8ross-sectional area of 1,550 m was conservatively used. This cor-responds to a projec2ed area of one reactor building above grade.

The use of a 1,550 m area is very conservative because both the reactor buildings are adjacent to each other and the combined projected area would be larger than the value used. Information from other sources, as indicated below, has also shown that this should be a conservative value.

1. In a paper by D.H. Walker (Reference 8), control room X/Q's were *experimentally determined for* floating power piants in wind tunnel tests. Different intake and exhaust combi-

nations were considered. Using the data for intake 6 2gd stack A e!gaust (Reference 8), X/Q values of 1.77 x 10 and 2.24 x 10 were found after adjusting the wind speed from 1.5 m/sec to 1 m/sec. These values are approximately two order-of-magnitudes lower than the conservatively calculated value for Quad Cities. *

D-4

2. In a wind tunnel test by P.N. Hatcher (Reference 9), a model industrial complex was used to test dispersions due to a wake. Data obtained from these tests show that K has a value less than 1, and decreases as the test poin£s are moved closer to the structure. In a study to determine optimum stack heights, R.N. Meroney and B.T. Yang (Ref-erence 10) show that for short stacks (6/5 of building height), K reaches a value of approximately 0.2 and

,_ decreases 81oser to the building. They concluded that the Halitsky methodology was *overly conservative.* These recent experimental tests show that K = 2 used to determine the X/Q for Quad Cities is a conservative estimate by at least a factor of 2 and possibly by 10 or more.

3. Field tests were made on the Rancho-Seco facility (Ref-erence 7), and X/Q values were obtained. The data indicate that the use of K = 2 is conservative.

c It was concluded that sufficient data and field tests exist to give a reasonable assurance that the chosen X/Q is a conservative one, over and above the conservatism implied by using the fifth percentile wind speed and wind direction factors. Based on the above discussion, the following equation is used in the calcu-lation of X/Q values.

X/Q = 2/AU E. MECHANISMS FOR REDUCING IODINE RELEASES The following mechanisms could result in. significant quantities of iodine being removed before they are released to the environ-ment. However, numerical credit for the plateout mechanisms is the only credit taken in the calculation of radiological consequences.

1. DRYWELL SPRAYS, SUPPRESSION POOL TO AIR PARTITIONING, AND CONDENSATION EFFECTS

Though manually operated, the drywell sprays will reduce the iodine source term if actuated. Even without the spray -

system, condensation will occur in the drywell and suppression chamber.

I The iodines in the air and suppression pool are expected to reach equilibrium due to this phenomenon.* Because the iodines have a preference to stay in water due to the equi-librium partition factor of over 400 established by the physical conditions in the containment, the iodines avail-able for release by air leakage will be reduced signif i-cantly. In addition, recent investigations after TMI (NSAC-14, Workshop on Iodine Releases in Reactor Accidents) have indicated that the iodine release assumption may be exces-sively conservative. Most of the iodine may be released as cesium .iodide instead of elemental iodine. The cesium iodide has a much higher solubility and ability to plateout than .

elemental iodine.

D-5

2. PLATEOUT

Although there is an implied factor of 2 iodine plateout in Regulatory Guide 1.3 source term, experimental evidence and the experience at TMI indicates that significantly larger plateout factors are common. The plateout removal constant used in this analysis is based on the lowest deposition velocity quoted in Reference 3. The other data quoted in Reference 7 indicate that the deposition velocities could be higher by a factor of 4, which would tend to increase the plateout.

3. REMOVAL THROUGH VALVES AND LEAKAGE HOLES Because the bypass leakage paths are through minute holes in valves and valve seats, the leakage will be subjected to filtration effects. Larger particulates could* tend to plug the leak* paths (Reference 11).

4. CONDENSATE WITHIN PIPES Condensation will occur within the pipes when the pipes cool down to ambient temperature. This could result in removal of iodines. and particulates from the gas phase.

F.* RESULTS The calculated radiation doses are given in Table D-2 and are found to be within the guidelines of General Design Criterion 19 and.SRP 6.4. .

D-6

-* REFERENCES 1.

2.

Standard Review Plan 6.4, Habitability Systems, Rev 1

(

Regulatory Guide 1.3, Assumptions used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accident for Boiling Water Reactors, Rev 2, June 1974

3. NUREG/CR-009, *Technilog ical Basis for Models of Spray Washout of Airborne Contaminants in Containment vessels,*

A.K. Posta, R.R. Sherry, P.S. Tam, October 1978

4. Standard Review Plan 15.4.9, Spectrum of Rod Drop Accidents

( BWR), Rev l

s. K.G. Murphy and K.M. Campe, *Nuclear Power Plant Control Room Ven~ilation System Design for Meeting General Design Criterion 19," l3th AEC Afr Cleaning Conference

6. D.H. Slade, ed., Meteorology and Atomic Energy, TID 24190

(_1968)

7.

G.E. Start, J.H. Cate, C.R. Dickson, N.R. Ricks, G.H. Ackerman, and J.F. Sagendorf, "Rancho-Seco Building Wake Effects on Atmospheric Diffusion," NOAA Technical Memorandum, ERL ARL-6 9 ( 19 7 7 ) . ,

8.

9.

D.H. Walker, R.N. Nassano, M.A. Capo, 1976, "Control Room ventilation Intake Selection for the Floating Nuclear Power Plant," 14th ERDA Air Cleaning Conference R.N. Hatcher, R.N. Meroney, J.A. Peterka, and K. Kothari, 1978, *Dispersion in the Wake of a Model Industrial Complex,"

NUREG 0373

10. R.N. Meroney and B.T. Yang, 1971, *wind Tunnel Study on Gaseous Mixing Due to various Stack Heights and Injection Rates Above an Isolated Structure," FDDL Report CER

71-72RNM-BTY16, Colorado State University 11.* H.A. Mqrewitz, R.P. Johnson, C.T. Nelson, E.V. Vaughan, C.A. Guderjahn, R.K. Hillard, J.D. McCormack*, and A.K. Posta,

Attenuation of Airborne Debris from Liquid-Metal Fast Breeder Reactor Accident~" Nuclear Technology, Volume 46, De.cember. 1979 tr.7

TABLE D-1 *

LOSS-OF-COOLANT ACCIDENT PARAMETERS TABULATED FOR POSTULATED ACCIDENT ANALYSES Design Basis

Assumptions I. Data and Asswnptions used to Estimate Radioactive Source from Postulated Accidents A. Power level, MWt 2,511 B. Burnup NA C. Fission products released from fuel (fue1 100%

damaged)

D. Iodine fractions Organic 0.04 Elemental 0.91 Particulate 0.05 II. Data and Assumptions Used to Estimate Activity Released A.

B.

c.

D.

E.

Primary containment leak rate, %/day Free volume of primary containment, cu ft Secondary containment release rate, %/day Leak rate through MSIV, scfh Number of main steam lines 0.75 2.75E+S 100 11.5 4

I F. Leak rate from turbine condenser complex, LO

%/day G. Volume and surface area (all four steam Ft 3 I

1 ines)

Between inboard and outboard MSIV 170 470 Outboard and turbine stop valves 761 5 1,693 5 Turbine condenser complex 1. 7xl0 6.SxlO H. Deposition velocity for iodines, cm/sec Particulate 0.012 Elemen*tal 0.012 Organic o.o I. Valve movement times (See* Note)

J. SGTS adsorption and filtration efficiencies, %

Organic iodines 99 Elemental iodine 99 Particulate iodine 99

Table D-1 (continued)

Design Basis Assumptions I. Dispersion Data, sec/m 3 A. Control room wake X/Q for time intervals of 0 to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months Bypass Leak SGTS

(.Chimney)

1. 29E-3 7.0E-4*

I 2 to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 1. 29E-3 . 6.4SE-6 8 to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7.61E-4 3.8iE-6 1 to 4 days 4.84E-4 2.42E-6 4 to 30 days 2.13E-4 1. 07E-6

O to 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months fumigation conditions assumed according to Regulatory Guide 1. 3 IV. Data for Control Room

'\ A. Volume- of contrcYl room, *ft 3 - -'5.83E+4 B.

C.

Filtered intake, cfm Efficiency of charcoal adsorber, %

2,000 99 I

D. Efficiency of HEPA, % 99.9 E. Unfiltered inleakage, cfm 10 F. Re~irculation flowrate o.o G. Occupancy factors:

0 to 1 day 1. 0 1 to 4 days 0.6 4 to 30 days 0.4 Note: The MSIV movement times are not applicable to the analysis because the valves will close before any. significant fuel failures occur.*

The control room HVAC intake valve movement times are not applicable because the calculated doses assume an unfiltered outside air intake of 2,000 cfm. for the first 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months post-LOCA

J TABLE D-2 DBA-LOCA RADIOLOGICAL CONSEQUENCES Doses (Rem)

CONTROL ROOM Thyroid Skin Whole-Body

1. B~pass Leaka~e

a. Activity inside control room 2.97 4.77E-l l.52E-2

b. Plume shine 2.03E-3

c. *oirect shine S.70E-2

2. Stack Release

a. Activity inside control room 10.10 1.96 1. 20E-l

b. Plume shine l.66E-2

TOTAL CONTROL ROOM DOSES 13.07 2.46 2.llE-1 Note: The values provided above represent 30-day integrated doses. The

,. doses are calculated assuming an unfiltered outside air intake of 2,000 cfm for the first 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months post-LciCA. At 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the con-trol room operators are assumed to remote manually activate the

. charco~l filtration unit

CONTROL ROOM HABITABILITY STUDY FOR DRESDEN- UNITS- 2 *AND* 3' COMMONWEALTH EDISON COMPANY Prepared By Bechtel Power Corporation Ann Arbor, Michigan Final. Report-November. 1981-Revised -December-1981 8112290318 811'21'7 PDR ADOCK 05000237 P _ _______ 'PDR

CONTROL ROOM HABITABILITY STUDY TABLE OF CONTENTS

1.0 INTRODUCTION

1-1 2.0 EXISTING DESIGN 2-1 3.0 TOXIC CHEMICAL SURVEY 3-1

4.0 RADIOLOGICAL ANALYSIS 4-1 5.0 PROPOSED HVAC DESIGN MODIFICATIONS 5-1

. 6. 0 RECOMMENDATIONS 6-1 FIGURE 1 Dresden Control Room HVAC Schematic APPENDIXES A .NUREG 0737, Item III.D.3.4 A-1 B NRC-Requested Information Required for Control B-1 Room Habitability Evaluation c Summary of Offsite TOxic Chemical Survey C-1 Table C-1: Potentially TOxic Chemicals Stored Within the Dresden Site Boundary Table C-2: Potentially TOxic Chemicals Stored at Fixed Facilities Within a 5-Mile Radius of Dresden Table C-3: Potentially TOxic Chemicals Transported

. on sarges Within a 5-Mile Radius of Dresden Table.C-4: Potentially TOxic Chemicals Transported on Railways Within a 5-Mile Radius of Dresden Table C-5: Potentially TOxic Chemicals Transported on Highways Within a 5-Mile Radius of Dresden ii*

.r Table of Contents (continued)

Appendixes (continued)

D Radiological Analysis for Control Room D-1 Habitability Following a DBA-LOCA Table D-1: Loss-of-Coolant Accident Parameters Tabulated for Postulated Accident Analysis Table D-2: DBA-LOCA Radiological Consequences

iii

.r ~

1.0 INTRODUCTION

A study is being conducted of the Dresden Units 2 and 3 control room habitability during toxic gas releases, radioactive gas releases, and direct radiation resulting from design basis accidents (DBAs). The study includes a survey of potential onsite and offsite sources of toxic chemical hazards which could jeopardize control room habitability, along with an analysis of control room doses resulting from a OBA loss-of-coolant accident (LOCA). The study is intended to satisfy the requirements for control room habitability as provided in Item III.o.3.4 of NUREG 0737, Clarification of TMI Action Plan Requirements. A copy of NUREG 0737, Item III.D.3.4 is provided as Appendix A.

The following report summarizes the results of the study. The analysis of the onsite and offsite toxic chemical survey is provided in Section 3.0. The analysis of the radiological cal-culations is provided in Section 4.0. The recommended design modifi6ations that address those results are included in Section s.o. A response to the *Request for Information Required for Control Room Habitability Evaluation,* as contained in Attach-ment l to Item III.D.3.4 of NUREG 0737, is provided as Appendix B*

1-1

2.0 EXISTING DESIGN The Dresden units 2 and 3 control room and its associated HVAC equipment room are located in the turbine building at eleva-tions 534' and 549', respectively. The HVAC system for Units 2 and 3 also services the Units 2 and 3 computer room (eleva-tion 517') and miscellaneous offices (elevation 534'). Return air is recirculated through the supply air handling unit or exhausted to the outside as conditions require. Mixed return air and outside air are filtered. The air handling unit has a hot water heating coil and a direct expansion cooling coil. Stearn humidifiers are located in the ducts. When activated by smoke sensors, the HVAC system switches automatically to a purge mode with 100% outside air.

The Dresden Unit l control room is located in the turbine building at elevation 534', adjacent and_open to the Units 2 and 3 control room

2-1

3.0 TOXIC CHEMICAL SURVEY 3.1 OVERVIEW A survey for potentially toxic chemicals stored or transported onsite or within a 5-mile radius offsite of Dresden Units 2 and 3 was conducted in accordance with the criteria outlined in NUREG 0737, Item III.D.3.4. The following discussion provides the survey methods, analysis methods and results, and conclusions of the toxic chemical survey.

3.2 ONSITE SURVEY METHODOLOGY The onsite survey was conducted to identify chemicals stored within the plant boundary. A list of potentially toxic onsite chemicals is provided in Table C-1 of Appendix c. The results of the onsite survey analysis are provided in Section 3.5 below.

3.3 OFFSITE SURVEY METHODOLOGY The offsite survey was conducted to identify chemicals stored or transported within a 5-mile radius of the Dresden site. Fixed industrial, municipal, and bulk storage facilities, as well as pipeline companies, local farms, and businesses, were contacted regarding the chemicals they stored. Chemicals transported by barge, rail, and highway* were also addressed. F'.or Dresden, commodities transported on the Illinois River; Elgin, Joliet, and Eastern Railway; Illionis Gulf Central Railroad; Atcheson, '!'Opeka, and Santa Fe Railway; Baltimore and Ohio Railroad; and the I-55 and I-80 interstate highways were considered. In accordance with Regulatory Guide 1. 78, only chemicals transported with a minimum shipment frequency of 10 per year by highway, 30 per year by rail, and 50 per year by barge were considered.

A survey of chemicals stored at, or transported to or from, fixed facilities was conducted by individually contacting each facility~

Although most of the requests for information received responses,_

a few facilities chose not to respond because of proprietary concerns. A listing of the firms *contacted and associated poten~

tially toxic chemicals, as well as a listing of facilities that did not respond, is provided in Table C-2 of Appendix c.

A survey of barge traffic on the Illinois River was performed using Reference 1 (see Appendix C). This reference provides a record of yearly tonnage of a given commodity category shipped on a given section of the river. For this survey, the section from the mouth of the Illinois River to Lockport, Illinois was used.

Conservatively, all barge traffic into, out of, within, and through this section is assumed _to pass by Dresden. Shipnent frequency was determined by dividing the yearly tonnage shipped

3-1

by an average barge size of 2,500 tons (reference Appendix C) *

This methodology is conservative because it assumes only one barge per shi?nent, while normal shipments may contain as many as four barges (Reference 3.2) * . Table C-3 of Appendix C lists the chemicals whose shi?nent frequencies exceed 50 shipments per year.

Unlike the Reference 1 information on barge traffic, there is no centralized source of meaningful data on railway and highway commodity traffic which is applicable to this survey. Data on railway traffic were obtained by individually contacting each of the railroads discussed above.. As noted in Append ix C, some information on commodity traffic by rail was not available. Data on highway commodity traffic was obtained by requesting infor-mation on chemicals transported to/from facilities within or near the 5-mile radius. This area includes chemical plants, bulk storage facilities, farms, and other chemical users/producers.

While these sources cannot provide a complete listing of the regional highway traffic, they are the only known source of information and therefore the only data available for evaluation.

Tables C-4 and C-5 of Appendix C provide a listing of potentially toxic c~emicals transported by railway and -highway, respectively.

The results of the off iste survey analysis are provid.ed in Section 3.5.

3.4 ANALYSIS METHODOLOGY The analysis of survey' results was modeled to conform to Regu-latory Guide 1.78, which discusses the requirements and guide-lines to be used for determining the toxicity of chemicals in the control room following a postulated accident. The guide! ines **for determining the toxicity of a given chemical include shipment frequencies, distance from source to site, and general properties of the chemical such as vaPor pressure and toxicity 1 imi t.

Three types of standard limits are considered in defining hazardous concentrations. The first limit is the toxicity limit, which is the maximum concentration that can be tolerated for 2 minutes without physical incapacitation of an average human.

If the toxicity limit is not available for a given chemical, a second limit called the short-term exposure limit (STEL) is used.

STEL is defined as the maximum concentration to which workers can be exposed for 15 minutes 'without suffering from irritation, tissue damage, or narcosis leading to accident proneness or reduction of work efficiency. The third limit is the threshold limit value (TLV), defined as the concentration below which a worker may be exposed 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months a day, 5 days a week without adverse health effects *

3-2

The threshold limit values, the short-term exposure limits, and the toxicity limit are taken from the following references.

1. Threshold Limit Values for Chemical Substances and Physical Agents in the Work Room Environment with Intended Changes for 1980. ACGIH Manual, P.O. Box 1937, Cincinnati, Ohio 45201

2. Physical and Toxic Properties of Hazardous Chemicals Regularly Stored and Transported in the Vicinity of Nuclear Installations, Committee on the Safety of Nuclear Instal-lations of the Organization for Economic Cooperation and Development, Nuclear Energy Agency, Paris, March 1976

3. Hazardous Chemical Data, CHRIS, Department of Transpor-tation, Coast Guard, October 1978

3-2a

The models developed to calculate the concentration of toxic chemicals in the control room in the event of an accidental spill are consistent with the models described in NUREG 0570. These include a consideration of the following factors:

a. There is a failure of one container of toxic chemicals being shipped on a barge, tank car, or tank truck releasing all of its contents to the surroundings. Instantaneously, a puff of that fraction of the chemical which would flash to a gas at atmospheric pressure is released. The remaining chemical is assumed to spread uniformly on the ground and evaporate as a function of time due to the heat acquired from the sun, ground, and surroundings. Further, no losses of chemicals are assumed to occur as a result of absorption into the ground, cleanup operations, or chemical reactions.

b. A spill from-a railroad tank car is assumed to spread roughly over a circular area. Similarly, a spill occurring on the highways is also assumed to spread over a circular area.

c. The initial puff due to flashing, as well as the continuous plume due to evaporation, is transported and diluted by the wind to impact on the control room inlet. The atmospheric dilution factors are calculated using the methodology of Regulatory Guide 1.78 and NUREG 0570, with partial building wake effects conservatively considered.

d. To determine which chemicals need monitoring, the control room ventilation systems were assumed to continue normal operation for the analysis. The chemical concentrations as a function of time were calculated and the maximum levels determined. These were compared to the toxicity limits.

Wherever the toxicity limits were not available, STEL values and TLVs published by the American Conference of Govern-mental and Industrial Hygienists (ACGIH) were used in lieu of toxicity limits.

e. Concentrations were calculated as a function of time following the accident to compare with the published toxicity limits, STEL values, and TLVs.

f. When the concentration in the control room did not exceed the toxicity limit within 2 minutes after detection by odor, operator action to isolate the control room was assumed. In such cases, monitors are not employed in the control room air intake. Where toxicity limits are not available, STEL values were used in lieu of toxicity limits *

3-3

The control room ventilation system is designed as discussed in Section 2.0. At present, there are no toxic chemical monitors installed to isolate the control room. Therefore, it was assumed that the ventilation system operates continu-ously at the design flowrates throughout the duration of the accident.

3.5 ONSITE/OFFSITE RESULTS The onsite chemicals listed in Table C-1 were analyzed and evalu-ated based on a fresh air intake of 2,000 cfm and no isolation.

The analysis shows that none of the chemicals stored onsite poses a problem with regard to control room habitability.

The offsite chemicals that were considered were:

o Chemicals stored at facilities o Chemicals transported in pipelines o Railroad traffic o Barge traffic o Highway traffic

a. Chemicals Stored at Facilities, Chemicals Transported in Pipelines, and Railroad Traffic These three categories are considered as follows. Each of the chemicals was evaluated based on toxic, physical, and chemical properties. Some were eliminated based on Regula-tory Guide 1.78 (Table C-2) criteria. The remaining chemi-cals were analyzed assuming a fresh air intake of 2,000 cfm to the air handling system and no isolation. At this flow-rate, without isolation, the following chemicals exceeded the TLV and STEL in the control room: ammonia, vinyl ace-tate, ethylene oxide, hydrochloric acid, chlorine, hydro-*

fluoric acid, acrylonitrile, formaldehyde, and methyl chloride. These are discussed below.

1) Ammonia The odor threshold for this chemical is 50 ppm. The analysis showed that after sensing the odor, the operators would have less than 1 minute to manually isolate the control room and put on breathing apparatus before the concentration in the control room reached toxicity limit (100 ppm). Hence, it is recommended that it be monitored

3-4

2) Ethylene Oxide This chemical has an odor threshold of 50 ppm, which is also its TLV. The operators can smell it at this level, and the analysis showed that the rate of concen-tration rise in the control room was such that there would be sufficient time for the operators to put on the breathing apparatus (after manual isolation of the control room) before the concentration reached the toxicity limit. Therefore, this chemical does not need.to be monitored.

3) Vinyl Acetate Vinyl acetate exists in liquid form with a pleasant odor. The odor threshold is 0.12 ppm, which is much less than the TLV limit (10 ppm). The analysis showed that the operators would have ample time to sense the chemical and manually isolate the control room and put on the breathing apparatus before the concentrations reached the STEL. Based on this, it is concluded that vinyl chloride does not need to be monitored.

4) Hydrochloric Acid Hydrochloric acid is shipped as a solution, and it was conservatively assumed that the solution was at its maximum strength (40%). The' odor threshold is 1 to 5 ppm and the toxicity limit is 35 ppm. The analysis showed that the concentration rise is such that there would be sufficient time for the operators to sense the odor (at 5 ppm) and put on breathing apparatus after manually isolating the control room. Based on this, it is con-cluded that HCl need not be monitored.

5) Chlorine The odor threshold for this chemical is 3.5 ppm. The analysis showed that the operators would have 135 seconds after sensing the presence of the chemical by odor and manually isolating the control room and putting on breathing apparatus before the concen-trations reached the toxicity limit (15 ppm)._ Hence, it is concluded that it need not be monitored.

6) Hydrofluoric Acid The odor threshold for hits chemical is 0.036 ppm.

The analysis showed that the operators would have 687 seconds after sensing the presence of the chemical by*

odor and manually isolating the control room and putting on breathing apparatus before the concentrations reached the toxicity limit (32 ppm). Hence, it is concluded that it need not be monitored.

3-5

7) Acrylonitrile The odor threshold for this chemical is 21.4 ppm. The analysis showed that the operators would have 250 seconds after sensing the presence of the chemical by odor and manually isolating the control room and putting on

.breathing apparatus before the concentrations reached the toxicity limit (40 ppm). Hence, it is concluded that it need not be monitored.

8) Formaldehyde The odor threshold for this chemical is 0.8 ppm. The analysis showed that the operators would have 120 seconds after sensing the presence of the chemical by odor and manually isolating the control room and putting on breathing apparatus before the concentrations reached the toxicity limit (10 ppm). Hence, it is concluded that it need not be monitored.

9) Methyl Chloride The odor threshold for this chemical has not been established and credit cannot be taken for operators to be capable of detecting its smell and isolating the con-trol room manually. Analysis showed that the unstated control room concentrations rise rapidly and reach toxicity limit' (125 ppm) within 2 minutes. Hence, it needs to be monitored.

b. Barge Traffic There are six categories of barge traffic: sodium hydroxide, alcohols, benzene and toluene, basic chemicals, nitrogeneous fertilizer, and other fertilizers. In the event of a release, the chemicals would flow into the river and mix, being diluted; or be confined to the lower deck of the barge and be released at a slow rate. Some chemicals are soluble and this would further reduce the release rate.

1) Sodium Hydroxode and Alcohols Sodium.hydroxide and alcohols are chemicals whose boiling points are higher than ambient temperature.

Sodium hydroxide has negligible vapor pressure at room

3-Sa

temperature; therefore, it does not need to be con-sidered. Alcohols are highly soluble in water. The odor threshold of alcohols is much lower than the TLV; therefore, they could be detected by smell and the control room could be manually isolated. The operators would have sufficient time to put on breathing apparatus before concentrations exceed the STEL in the control room.

2) Benzene and TOluene Benzene and toluene are not shipped along the segment of the river near the Dresden station.

3) Basic Chemicals This category is comprised of a large nlD'!lber of chemicals.

The published information does not identify the chemicals by tonnage and number of shiprnents. The u.s. Army Corps of Engineers (responsible for compiling this data) was contacted to obtain the information on indi-vidual chemicals, and this information was not avail-able. Due to the large nlD'!lber of chemicals (toxic and nontoxic) involved, it is felt that the actual nlD'!lber of individual shiprnents for toxic chemicals would not exceed the shipment frequency for barges given in Regulatory Guide 1.78. Therefore, basic chemicals were not analyzed.

4) Nitrogeneous and Other Fertilizers This is a broad category; most of the fertilizers are in solid form and are not toxic gases. Ammonia is included in this category. As discussed above for other chemicals, the release of such fertilizers would be confined to the lower deck of the barge, and a large fraction coming in contact with water would be dis-solved. Also, the offsite analysis of chemicals indi-cates that ammonia needs to be monitored, and therefore barge accidents involving ammonia are not specifically evaluated.

c. Highway Traffic Highway traffic was considered as discussed in Section 3.3 of this report.

3-6

4.0 RADIOLOGICAL ANALYSIS General Design Criterion 19, Standard Review Plan (SRP) 6.4, and NUREG 0737, Item III.D.3.4 require that adequate radiation pro-tection exist to permit control room access and occupancy for the duration of a design basis accident (DBA). The radiological analysis, provided in Appendix D, considered the loss-of~coolant accident (LOCA) as the worst-case DBA and assumed main steam isolation valve (MSIV) leakage at technical specification limits.

Although several natural mechanisms exist to reduce or delay radioactive release to the environment, as discussed in Appen-dix D, credit was taken only for iodine plateout on surfaces of the steam lines and condenser and radioactive decay prior to release. The analysis also assumed that the control room HVAC system was designed with the proposed modifications discussed in Section 5.3. A detailed discussion of the methodology and assumptions of the analysis, as well as the conservatism of the approach, is included in Appendix D.

The following results are 30-day integrated doses in the control room based on the intake of unfiltered outside air for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months following the LOCA, and filtered outside air thereafter. The dose guidelines provided in SRP 6.4, Acceptance Criterion 8 are also provided for comparison purposes. The thyroid and skin doses consist of contributions from airborne radioactivity inside the control ~oom. The whole-body dose consists of contributions from airborne radioactivity inside and outside the control room, as well as direct shine from activity within the reactor building above the refueling floor.

TOTAL CONTROL ROOM DOSES (Rem)

Thyroid Skin Whole-Body Dresden Units 2 and 3 l.SOE+l 2.82 3.16E-l SRP 6.4, Guidelines for Control 30 30 5 Room As evidenced by these results, the control room HVAC system, with the design modifications discussed in Section 5.3, meets the radiological protection requirements of General Design Criter-ion 19 and SRP 6.4. *

4-1

5.0 PROPOSED HVAC DESIGN MODIFICATIONS 5 .1 OVERVIEW The following section presents proposed modifications to the existing control room HVAC system to meet the intent of NUREG 0737, Item III.D.3.4 and SRP 6.4, and to satisfy the requirements of General Design Criterion 19 regarding control room habitability following a radiological DBA. These modifications include the addition of a redundant system (train B) consisting of an air handling unit (ABU), return air fan, cooling system, associated piping, ducts, dampers, and appurtenances, and an air filtration unit (AFU) common to both air handling systems.

5.2 EMERGENCY ZONE SRP 6.4 defines the boundaries for a control room emergency zone.

Within this zone, the plant operators are adequately protected against the effects of accidental radiological gas and toxic gas releases. This zone also allows the control room to be maintained as the center from which. emergency teams can safely operate in a design basis radiological release.

To satisfy this requirement, the following areas are included in the emergency zone.

a. Main control room for Units 1, 2, and 3, which includes all critical documents and reference files, and toilet and locker rooms for Unit l

b. Computer room for Units 2 and 3

c. New HVAC equipment room, which houses the new train B system Areas outside the emergency zone, which ar~ normally serviced by the existing AHU system (train A), shall be isolated in emergency conditions. Suppor~ rooms such as the kitchen and offices are accessible to operators with the aid of breathing equipment. The existing HVAC equipment room is also not included in the emer-gency zone.

5.3 PROPOSED MODIFICATIONS The proposed HVAC system design modifications are described below. Figure .1 provides a schematic of the proposed system.

a. The Unit 1 control room will receive cooling from the Units 2 and 3 main control room HVAC system.

5-1

b. Existing supply AHU train A, return air fan A, and all related ductwork will be utilized.

c. New supply AHU train B will be located in a new HVAC equip-ment room. AHU train B will be sized to supply the emer-gency zone as discussed in Section s.2. Ducts from new AHU train B will be connected to the corresponding ducts of the existing air handling system. A suggested possible arrange-ment is outlined in Figure l.

d. New return air fan B will return air to new supply AHU train B. New AHU train B will also have outside air of 2,000 cfm.

e. A new AFU, sized to accommodate 2,000 cfm, will be located in the new HVAC equipment room. This unit will consist of a prefilter, electric heating coils, high-efficiency par-ticulate air (HEPA) filter, charcoal filters, HEPA filter, and two full-capacity fans. The AFU will be in compliance with Regulatory Guide 1.52.

f. A new 100%-capacity cooling system for train B will be installed in the new HVAC equipment room.

g. Bubbletight and low-leakage dampers will be used as shown in Figure 1.

5.4. MODIFIED SYSTEM OPERATION For normal conditions, the AHU train A system will operate as discussed in Section 2.0.

For an emergency condition, as determined by radiation monitors in the reactor building ventilation manifold, system operation will be as follows. Within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the bubbletight isolation dampers will isolate the normal outside air intake to the AHUs and all ventilation zones which are not mentioned in Section 5.2 above. The outside air damper to the new AFU will be remote manually opened and an AFU fan will begin supplying filtered air to one AHU train. The return air fan will route the return air to the associated ABU train. Barring component failures in the operating AHU train, the system will continue to operate in this manner for the duration of the emergency.

On failure of airflow in the operating AHU train system, that train is automatically isolated and the redundant train is ener-gized. Outside air will be supplied to the redundant AHU train by an AFU fan in this operating .mode. The return air .fan will route the return air to the associated AHU

5-2

In the event that toxic gases are detected as discussed in Section 3.5 of this report, all outside air intakes and all ventilation zones which are not mentioned in Section 5.2 will be isolated. The AHU will supply 100% recirculated air to the emergency zone.

I .

5-3

. I 6.0 RECOMMENDATIONS Based on the results of the radiological analysis, it is recom-mended that the control building HVAC system design incorporate the modifications discussed in Section 5.3.

Based on the results of the toxic gas analyses, it is recommended that a monitor be added to the fresh air intake to detect ammonia.

The system should incorporate automatrc isolation of the fresh air intake upon detection of ammonia *

6-1

DR.ESDEN F_lyUR.E- 1 CONTROL RM HVAC sc.µEMATIC.

REVl~*OIJ'

~fl!.

0

8118/&f I 1 10/ii/61 I

fe'}O Clt1 R.a.

~f~! I FllOf1 ()Pf!~~

EJll'!>T. ll .A..f. 'A (OUM)

--~~~-l'----1'"------------1

__ J µoi!S'5L.L-----.~,_...-.""1------T---..L--- ~,C.OOC:PH 'lA.

--~,.....--~

(IC.,000)

~ *,.* ...........o..;;;...__ _-a::,_~ VUl'T 1 MAIN c.ot.l'TR.01.. II.~

(21COO) E.LlV. '!> !ool' -()

Lt:ll1' ya MAit.i Cg.!TllOL ltOOM

"-£\/'. 531'0" l0c.Fl'1)

II o

" *~ ..J ..

~. £¥Fll.1'* I!====--------+--=-==+--...,_..~--

~,../.'.:

- ._ _,.._M

~i .. ~ :,

t '~

(2,DOOCP'M)L &<>&*

E~ () L

~ (9400)

Al.TE~ ~*e*

rooo c."1 2000*CTl'1 /

IJl!.W ,ti..~.u: t!!i"

!4,<<10 C..l't1 **1 1"400Cl'r1 (1400 UH)

~Ml~Tle5

£Mt,llito0.IC"f' Al" Qut.NT!nft

( ,..~ ...... *,,,:)

\...OW LE.H>GL ~

ll)Vf'}el. t '1lC.Ht Ol>.M p*Ut.

'TO!UC. CA<:i OtU.£.TO....

~,<> ... IA

APPENDIX A NUREG 0737, ITEM III.D.3.4 CONTROL ROOM HABITABILITY REQUIREMENTS

JII.D.3.4 CONTROL~ROOM HABITABILITY REQUIREMENTS

Position In 1ccordance with Task Action Pl1n ft.em JII.D.3.4 and control l'OOM habitability, licensees 1hall assure that control f'OOll operators will be adequately protected against the effects of accidental release of toxic 1nd radioactive gases and that the nuclear power plant can be safely operated or shut dovn under design

- sis accident conditions (Criterion 19, *control Room.* of Appendix A, *General Desfgn Cr1t.erfa for Nuclear Power Plants,* to 10 CFR Part 50).

Changes to Previous Reguf rements 1nd Guidance There are no changes to the prevfous-nquiraents.

Clari ff catfou (1) .All 1fcens.es aust .ake a subaf ttal to the NRC regardless of whether or not they aet the criteria of the referenced Standard Review Plans (SRP) sect.ions. The new clar1ffcatfon specifies that licensees that eeet the criteria of the SRPs 1hou1d*provfde the basts for their conclusion that SRP 6.4 requf reeents ire aet. Licensees aay establish this basis by referencing past 1ubmittals to the NRC and/or providing new or 1dditional fnfor91tfon to supplement past 1ubmittals.

(2) All 1fcens1es with control rooas that aeet the criteria of the following 11ctf ons of the Standard Review Plan:

2.2.1-2.2.2 Identification of Potential Hazards in Site Vicinity 2.2.3 Evaluation of Potential Accidents; 6.4 Habit.ability Systems shall report their findings regarding the specific SRP sections as explained

elev. The following docU11ent1 should be used for guidance:

(a) Regulatory Guide 1.78, *Assi.nptions for Evaluating the Jqbitability of Regulatory Power Plant Control ROOll During a Postulated Hazardous

.ch.. ical Release*;

(b) Regulatory Guide 1.95. *Protection of Nuclear Power Plant Control loom Operators Against an Accident Chlorine Release"; and~

(c) It. G. Murphy and It. M. Cupe. *HuclHr Power Plant Control loom Yentf latfon Syst.ea Design for Meeting General Design Criterion 19, 11 13th AEC Air Cleaning Conference. August 1974.

lic1n11es 1ha11 1ubllit the results of their findings 11 well as the basis for those findings by January 1. 1981. In providing the basis for the habitability finding. licensees .ay reference their past 1ubmittal1.

Licensees should. hovevtr, ensure that these 1ubmitt1l1 t"efJect the current*facilfty design and that the information requested in Attachment 1 h provided *

JII.D.3.4*1 . 3-197

'* I 003234 (3) A11 licensees with control.l'OOlls that do not 11eet the criteria of the above-lhted references, Sundard Review Plans, Regulatory Guides. and other references.

These licensees shall perfor11 the necessary evaluations and identify appropriate 90difications.

Each licensee subllittAl shall include the results of the analyses of control room concentrations from postu1attd accidental re1ease of toxic gases and control roOll operator radiation exposures froe airborne radf oactf ve aateria1 and direct radiation resulting from design-basis accidents. The toxic gas accident analysis should be perforaed for a11 potential hazardous chemical releases occurring either on the 1ite or within 5 af les of the plant-site boundary. Regulatory Gufde 1.78 lists the chemicals 110st Coal)Only encountered fn the evaluation of control room habitability but is not all inclusive.

The design*basf s-accfdent (DBA) radiatfon source ttr11 should be for the loss*ot-coolant accident LOCA containitent leakage and engineered safety feature (ESF) leakage contribution outside contain11ent as described fn Appendix A and B of

Standard Revfew Plan Chapter 15.6.5. In addition, boiling-water reactor (BWR) facility evaluations should add any leakage froa the aain steam isolation valves (MSIV) (i. ***valve-stem leakage, valve seat leakage, main steam fsolation valve leakage control system release) to the cont.afninent leakage and ESF leakage following a LOCA. Thf1 should not be construed as altering the staff recoamtendations fn Section D of Re9Ylatory Guide 1.96 (Rev. 2) regarding MSIV 11ak1ge*control systems. Other DBAs should be revfewed to deteT"lline whether they *ight constitute a 90re*11vere control*root1 hazard than the LOCA.

In addition to the accfdent-analysis results, which should either identify the possible need for control-roo* 80difications or provide assurance that the habitability systems will operate under all postulated conditions to permit the *control-room operatori to reNin in the control roo11 to take appropriate actions required by General Design Criterion 19, the licensee should submit sufficient inforlk\tf on needed for an independent evaluation of t.he adequacy of the habitability 1yst111s. Attachllent 1 lfsts the inforsation that should be provided along with the licensee's evaluation *

!J>plfcabflfty This requirement applfes to all operatfng rtactors and operating license applicants.

hip 1ementati on Licensees shall submit their responses tot.his request on or before January.l,*

1981. Applicants for oi>erating licenses shall submit their responses prior*to f ssuance of a full*p°"er 1fc1nse. Modifications needed for compliance with the control*rooa habitability requirements specified fn this letter should be identified, and a schedule for completion of the 80dificat1ons should be provided. l11Pl*mentation of such aodifications should be started without awaiting the results of the staff revi.w. Additional needed 110difications, if any, identified by the staff during fts revi9" will be *pecified to licensees

3-198 UI.D.J.4-2

\ .

I

003234*

Typt of Aevf N A po5timplecnentatfon revfe~ will be perfor11ed.

DocU11tntatfon Reguf,..d ly January 1, 1981 licensees shall provide the fnfonnatfon ducr1bed fn Att.chlllent 1. Applicants for an operating license shall submit their re5ponses prior io full-power lfcensfng.

Technical Specf ff catf on Changes Regufred Changes to technical 1pecfffcatfons will be required.

Ref1rences NUREG-0660, ?tee 111.D.3.4.

letter fl"Oll D. G. Efstnhut, IRC, to All Operating Reactor Lfcensees, dated Nay 7, 1980.

JIJ. D. 3. 4*3 3-199

003234 111.0.3.4, ATTACHMENT 1, INFORMATION REQUIRED FOR CONTROL-ROOM HABITABILITY £VALUATION (1) Control*rooai *ode of operation, i.e., pressurization and filter recirculation for radiological accident holat1on or chlorine release

,(2) Control-room characteristics (a) air vol~ control rooe (b) control-room emergency zone (control room, critical files, kitchen.

washroom, computer room, etc.)

(c) control-room ventilation system sche*atfc with nonnal and eeergency air-flow rates

. (d) 1nftltratfon leak.age rate (e) high efficf ency particulate air (HEPA) ff lter and charcoal adsorber efficiencies (f) closest distance between contairwient and air intake (g) layout of cont1"01 room, air intakes, containment building, and chlorine, or other chetaical storage facility with di*ensions (h) control*f'OOll shielding fnclud1ng radiation 1tre111ing from penetrations, doors, ducts, stainfays, etc.

(i) automatic fsolation cap1bilfty*da11Per closing time, damper leakage and area (j) chlorine detectors or toxic gas (local or f'elllote)

(k) self-contained breathing apparatus availability (nLmber)

(1) bottled afr supply (hours supply)

(*) e11ergency food and potable water supply (how aany days and how aany people)

(n) control-room personnel capacity (nor9al and *ergtncy)

(o) potaufm iodide drug supply (3) Ons1te storage of chlorfnt and other hazardous chemicals (a) total *ount and sfze of container (b) closest distance fro11 control*roo* air intake 3-200 III.0.3.4-4

(4) Offsite aanufacturing, storage. or transportation facilities of hazardous chemicals (a) identify facilities withtn a S-*tle radius; (b) distance fro11 control room (c) quantity of hazardous. chnfcals fn one container (d) frequency of hazardous chemical transportatton traffic (truck, rail, and barge)

(5) Tethnical 1p1~ifications (refer t.o standard technical specifications)

(a) chlorine detection 1y1te111 (b) control*roo* ..ergency filtration system including the capability to

ain~tn the control-room pressurtzatton at 1/8-in. water gauge, vertftcation of 11ol1tton by test 1tgn1ls and dallper clo1ur1 tt*ts, and filter tasting requir"llltnts.

3-201 III. D. 3. 4*5

APPENDIX B NRC-REQUESTED INFORMATION REQUIRED FOR

. CONTROL ROOM HABITABILITY EVALUATION

The following list of responses corresponds directly to the items requested by Attachment l to NUREG 0737, Item III.D.3.4. The responses reflect the modified control room HVAC system design as discussed in Section 5.3 of this report.

Item Response 1 Upon detection of high airborne radioactivity in the reactor building ventilation manifold, the control room HVAC system will enter the emergency mode of operation within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

In this mode, normal makeup and selected return air ducting are remote manually isolated and the control room emergency zone is pressurized by once-through makeup air passing through an emergency filter unit.

Upon detection of high ammonia concentrations in the control room HVAC fresh air intake, the system will automatically be switched to the isolation/recirculation mode of operation.

In this mode, the operators will put on breathing apparatus until the toxic chemical concentrations are ,reduced to below safe levels.

Upon operator detection of vinyl acetate, ethylene oxide, and hydrochloric acid, the system will be manually placed in the isolation/recirculation mode of operation. In this mode of operation, the operators will put on breathing apparatus until the toxic chemical concentrations are reduced to below detectable levels.

2 Control Room Characteristics

a. Control room air volume: The air volume of the control room emergency zone is approximately 132,000 cubic feet, including 104,000 cubic feet for the main control room.

b. Control room emergency zone: The control room .emer-gency zone includes the main control room for Units 1, 2, and 3; computer room for Units 2 and 3; toilet and locker rooms for Unit l; and the new HVAC equipment room.

c. Control room ventilation system schematic: Figure l of this report provides a proposed ventilation system schematic for th~ tontrol room emergency zone indi-cating normal and emergency airflows.

B-1

Item Response Infiltration leakage rate: Infiltration leakage into the control room is negligible because the control room will be maintained at a positive pressure with respect to adjacent rooms during both normal and emergency conditions. For emergency conditions, makeup air will be limited to a maximum of 2,000 scfm. Backflow infiltration is assumed to be 10 scfm.

During isolation/recirculation conditions, infiltration is initially negligible because the control room,will be at a positive pressure at the time of system iso-lation. Infiltration following isolation is conserva-tively assumed to be 105 cfm following system isolation.

e. HEPA filter and charcoal adsorber efficiencies: The HEPA filters in the emergency filtration train are rated at 99.97% efficiency in removing particulates of 0.3-micron size and larger. The charcoal filters in the emergency filtration train are rated at 99% effi-ciency for removal of elemental and organic iodine.

f.

Closest distance between containment and air intake:

The Units 2 and 3 control room HVAC system intake (elevatio~ 549') is located approximately 162 feet from the closest wall of the secondary containment reactor building. Additionally, the standby gas treatment system (SGTS) exhaust to the main chimney for Units 2 and 3 is located approximately 444 feet laterally and 278 feet above the HVAC system intake.

g. Layout: A layout drawing showing the relative location of the control room, HVAC system intake, toxic gas monitors, turbine building, SGTS main chimney, and the containment is shown in attached Figure B-1.

h. Control room shielding: The control room design con-sists of poured-in-place reinforced concrete with 6-inch floor and ceiling slabs and 18- to 27-inch walls. The radiation streaming effect in the control room *is considered negligible during normal operation and provides a 30-day integrated whole-body dose of 101 mRem.

post-LOCA. Refer to FSAR Section 12.2 for further details.

i. Automatic isolation capability, damper information:

Isolation of the normal makeup air intake takes approxi-mately 20 seconds. The makeup air intake and exhaust damper will be bubbletight with an area of 25 square feet each and a leakage factor of zero. Off ice zone duct will be isolated with bubbletight dampers with a leakage factor of zero for the return air, and a low leakage type damper for the supply air. The Unit 1 control room 'HVAC supply and return ducts will be isolated with bubbletight dampers.

B-2

Item Response

j. Chlorine or toxic gas detectors: A toxic gas detector will be provided for ammonia.

k, Self-contained breathing apparatus availability and

1. bottled air supply: Five self-contained breathing apparatus are available in the control room, each with a 20-minute air supply. A manifolded bottled air system is currently being installed. The system is capable of supplying air to four people for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months or five people for 6-1/2 hours.

m. Emergency food and potable water supply: The control room area contains food provisions sufficient to supply at least five people for a week. Adequate water is also available near the control room.

n. Control room personnel capacity: During normal oper-ation, the control room will contain five people. In emergency conditions, the personnel capacity will be limited to five people by the bottled air system capabilities.

o. Potassium iodide supply: A supply of potassium iodide is available in the plant.

3 Onsite Storage of Chlorine and Other Hazardous Chemicals Refer to Table C-1 of Appendix C for this information.

4 Offsite Manufacturing, Storage, or Transportation Facilities of Hazardous Chemicals*

Refer to Tables C-2 through C-5 of Appendix C for this information.

5 Technical Specifications

a. Chlorine detection system: Because no chlorine detec-tion system exists at the present time, no technical specification has been written for it. The technical specification will be reviewed and revised, as necessary, to address the. proposed modifications.

b. Control room emergency filtration system: Because no control room emergency filtration system exists at the present time, no technical specification has been written for it. The technical specifications will be reviewed and revised, as necessary, to address the proposed modifications.

B-3

!2fi:L:J vni.~ -

1JtJ11*. t.( ~ I

-- . --*=~o-e*---~

t:oo' l!>U?C1 i

©

'!-OVfH A.IJ K . P.iol.Y

/W;~

.f:Q!:!!ltOI..

~

\.(Al!,~~

~l..D~

Ul.Jt"f t _ _ _ __.._ __:_Ul..lt 1 1 -------

' ' " " * - - - \J>.111 :3 IZ(Vt<;l()N: I ~Te. 10-1t-e1 DRESDEN C.O~TROL IC!OOM

~AP->ITAP->ILITY c.E1Jel<AL Pl.AIJ"T L.A'!'OUT F IC.Vll.E.. &-1 NOT "TO "i><:A\..,E..

TABLE C-1 POTENTIALLY TOXIC CHEMICALS STORED WITHIN THE DRESDEN SITE BOUNDARY Chemical Quantity(l) Location Ammonium nitrate 2,000 gal. Decontamination area Caustic soda 4,200 gal. Turbine building (Dl)

Carbon dioxide 7.5 tons Turbine building (D3)

Carbon dioxide 4 tons Behind laundry. ( Dl)

Halon 1301 400 f t 3 Turbine building ( D2)

Hydrogen 35,000 scf Between discharge canal and filter building Hydrogen 130,000 cu ft Same as above, only in at 2,640 psi truck Nitrogen liquid 8,000 gal. Between reactor building Unit 3 and records storage building Nitrogen, liquid 500,400 cu ft Same as above, only in at 15 psi truck

Polyacrylic acid Sodium Sodium Sodium hydroxide hydroxide hydroxide 6,000 gal.

10, 000 gal.

500 gal.

250 gal.

In building near crib house ( Dl)

Turbine building (D3)

Radwaste building Turbine building (D2)

Sodium hydroxide 250 gal. Turbine building (D3)

Sodium hydroxide 3,600 gal. In truck next to above tanks of sodium hydroxide Sodium hypochlorite 36,000 gal. Underground Sodium hypochlorite 4,000 gal. In truck next to tank above Sulfuric. acid 5,000 ga1. Turbine building (Dl)

Sulfuric acid 5,000 gal. Outside turbine building .(D3)

Sulfuric acid 500 gal. Radwaste building Sulfuric acid 250 gal. Turbine building (D2)

Sulfuric acid 250 gal. Turbine b~ilding (D3)

(l)Wherever multiple containers of the same chemical are stored in close proximity, the quantity of the largest container is provided.

TABLE C-2 POTENTIALLY TOXIC CHEMICALS STORED AT FIXED FACILITIES WITHIN A 5-MILE RADIUS OF DRESDEN(!)

Distance Facility( 2 ) (miles) Chemical Quantity< 3 , 5 >

Air co 2.40 Carbon dioxide (pipe- 24/.4 line) 2.40 Carbon dioxide 50 gal.

2.40 Chlorithane 500 tons at 200 psi Al urnax-Mill 2.85 Argon, liquid 600,000 ft 3 <4 >

2.85 Chlorine 1 ton 3 2.85 Nitrogen, liquid 73,000 ft A.P. Green Refractory 1.95 Monoaluminum phosphate 1, 500 gal.

35% phosphoric acid 3 I 200 gal.

(technical grade)

Propane 5,000 gal.

Armak 3.70 Acrylonitrile 210,000 lb 3.70 Anhydrous ammonia 150,000 lb 3.70 Fatty amines 750,000 lb 3.70 Formaldehyde 110,oog lb 3.70 Hydrogen 110 ft 3.70 Isopropol alcohol 136,000 lb 3.70 Methyl chloride 200,000*lb 3.70 Nitrogen, liquid 1,200 scr 3.70 Quaternery chlorides i~g,ooo lb 3.70 Natural gas (pipeline) 6(5) 3.70 Nitrogen (compressed) 3 (pipeline) 3.70 Hydrogen (pipeline) 6(5)

Bols farm 0.85 Anhydrous ammonia 2 tons Card ox 3.50 Carbon dioxide 400 to~s>

2 *.45 Carbon dioxide (pipe- 12/2.5 line) 3.50 Carbon dioxide (pipe- 2010.4< 5 >

line)

Table C-2 (continued)

Distance Fae il i t / 2 ) (miles) Chemical Quantity< 3 ,s>

ollins Station 4.9S Argon JOO ft 3 < 4 >

4.9S Ammonium hydroxide 6, 000 gal.

4.9S Carbon dioxide SO ton 3 ( 4 )

4.9S Helium 224 ft3 (4) 4.9S Nitrogen 224 ft(4) 4.9S Propane, liquid 100 .lb 4.9S Sodium hydroxide lS,000 gal.

4.9S Sodium hypochloride 3,000 gal.

4.9S Sulfuric acid lS,000 gal.

3 Durkee Foods 3.ls Nitrogen 800 I 000 f t 3 3.lS Hydrogen l,7SO,OOO ft 3.ls Sodium hydroxide 2SO,OOO lb 3.ls Sulfuric acid 200,000 lb 3.ls Anhydrous ammonia 10,000 lb 3.lS Gasoline SOO gal.

3.ls No. 6 fuel oil 60,000 gal.

3.lS Therminol 66 60,000 gal.

3.ls Chlorine Dolinger farm 1. so Anhydrous ammonia 2 tons Dow Chemical No information was provided*

avo-Mechling 4.2S Uran 1,000,000 gal.

Exxon Chemical Americas No information was Exxon Company, USA provided General Electric 0.60 Nitric acid (62%) . s, 3SO gal.

0.60 Sodium hydroxide (SO%) S,920 gal.

Hydrocarbon Transport 2.00 Butane 6(S)

. . . ( s)

(pipe! ine) 4.00 Butane lO(S) 4.00 Butane . 10 ( s) 4.00 Ethane 1~5) 2.00 Isobutane 6 4.00 Isobutane lO(S) 4.00 Isobutane 10< 5 >

4.00 Natural gas 10< 5 >

2.00 Propane 6~5) 4.00 Propane lO(S) 4.00 Propane 10< 5 >

Table C-2 (continued)

Distance Facility( 2 ) (miles) Chemical Quantity< 3 , 5 >

ooka wastewater 4.65 Chlorine 150 lb treatment Midwestern Gas Trans- 4.00 Natural gas 30 mission (pipeline)

Mobil Chemical No information was provided Mobil Oil No information was provided Natural Gas Pipeline 1.40 Natural gas 30 (pipeline) 1.10 Natural gas 36 Northern Illinois Gas 2.45 Diethanol amine Company 2.45 D~ethylene glycol 2.45 Hydrogen 3.70 Hydrogen (pipeline) 3.70 Natural gas (pipeline) 3.70 Nitrogen, compressed (pipeline) 2.45 Nitrogen, liquid 8,900 gal.

2.45 Metyl alcohol 10, 000 gal.

2.45 Petroleum naphtha 160,000 barrels 2.45 Potassium nitrate 80 lb 2.45 50% sodium hydroxide 6,600 gal.

2.45 Sodiilrn hypochlorite 55 gal.

2.45 93% sulfuric acid 6,'600 gal.

Northern Petrochemical No information was provided Reichhold Chemical No information was provided Shady Oaks Trailer Park 4.90 Chlorine 150 lb Waste Water Facility Includes pipelines.

<2 >This list includes only those facilities with potentially toxic chemicals, or those from which no information was received.

<3 >wherever multiple containers of the same chemical are stored at the same

( )facility, the quantity of the largest container is provided.

4 Standard type gas bottles

<5 >ouantities for pipelines are expressed as pipe diameter (inches)

TABLE C-3 POTENTIALLY TOXIC CHEMICALS TRANSPORTED ON BARGES WITHIN ACI)MILE RADIUS OF DRESDEN Chemical Category< 2 > Yearly Shipment (tons)

Alcohols 335,612 Basic chemicals 1,730,666 Nitrogenous fertilizers 720,819 Other fertilizers 403,482 Sodium hydroxide 293,228

(!)Data are based qn barge traffic along the Illinois River from the mouth of the Illinois River to Lockport, Illinois, 0.35 mile from the Dresden site. The source of the infor-mation is Waterborne Commerce of the u.s., U.S. Army Corps of Engineers, 1978 (latest edition).

2

< >The chemical categories listed above are those which were determined to pass by the Dresden site with a minimum frequency of 50 times per year. Shipment frequencies were calculated using a 2,500-ton barge capacity.

TABLE C-4 POTENTIALLY TOXIC CHEMICALS TRANSPORTED O~l)

RAILROADS WITHIN A 5-MILE .RADIUS OF DRESDEN Quantity Distance of Individual Railroad (miles) Chemical Container (tons)

Atcheson, Topeka, and 4.00 No inf or-Santa Fe mation was provided Baltimore and Ohio 3.70 No inf or-mation was provided Elg in, Joliet, and 2.45 Anhydrous 81 Eastern ammonia 2.45 Carbon 79 dioxide 2.45 Ethylene 84 2.45 Ethylene 89 oxide

2.45 2 *. 45 Hydrochloric

(muriatic) acid Liquif ied petroleum gas 97 75 2.45 Vinll 96 ace ate 1.45 Alkaline 76 corrosive liquid*

l. 45 Resin 94 solution 1.45 Styrene 98 monomer, inhibited

Table C-4 (continued)

Quantity Distance of Individual Railroad (miles) Chemical Container Illinois Gulf Central 4.00 Acryloni trile 20,600 gal.

Alkanesul- 20,000 gal.

fonic acid Butane 33,000 gal. (2)

Butyl acetate 20,000 gal.

Butyl alcohol 20,000 gal.

Chlorine 33,000 gal. ( 2)

Denatured 20,000 gal.

alcohol Ethylene oxide 20,000 gal.

Formaldehyde 20,000 gal.

Heptane 20,000 gal.

Hexane 20,000 gal.

Hydrochloric 20,000 gal.

acid Isobutane ( 2) 33,000 gal.

Liquif ied petro- ( 2) 33,000 gal.

leum gas Petroleum 20,000 gal.

nap th a Potassium 20,000 gal.

hydroxide Propylene 20,000 gal.

oxide Sodium 20,000 gal.

hydroxide Sulfuric acid 20,000 gal.

Toluene 20,000 gal.

Transported on the 1.44 Acrylonitrile 140,000 lb Elgin, Joliet, and Eastern by Armack Anhydrous 165,000 lb ammonia Fatty amines 140,000 lb Formaldehyde 140,000 lb Methyl chlor.ide 120,000 lb (l)The chemicals listed above pass by the Dresden site with a minimum frequency of 30 times per year.

( 2 ) This is the amount of gas in liquid gallons.

TABLE C-5 POTENTIALLY TOXIC CHEMICALS TRANSPORTED(£~

HIGHWAYS WITHIN A 5-MILE RADIUS OF DRESDEN D11: lsetasn) t2)

(m Quantity< 3 >

Highway Chemical Coll ins Road 1.95 Monoalurninurn phosphate 13,333 lb 85% phosphoric acid 26,667 lb Durkee *Foods 4.00 Nitrogen 40,000 lb Hydrogen 10,000 lb Sodium hydroxide 45,000 lb Sulfuric acid 45,000 lb Anhydrous ammonia 4,000 lb Gasoline 5,500 lb No. 6 fuel oil 45,000 lb Therminol 66 36,000 Chlorine 2,250 Lorenzo Road 3.00 Ammonium hydroxide 3,000 ~at 4 )

Argon 224 ft ,

Carbon dioxide 36,0003lb Nitrogen 224 ft(4)

Propane 100 lb Sodium hydroxide 3*, 500 gal.

Sodium hypochloride 3,000 gal.

Sulfuric acid 3,000 gal.

State Route 6 2.00 Argon 450,000 ft 3 ( 5 )

Anhydrous ammonia 40,000 lb Carbon dioxide 17 tc>ns Fatty amines 45,000 lb Formaldehyde 46' 0.00. l!J Hydrogen 8,000 ft Isopropol alcohol 41,000 lb 3 Nitrogen 600,000 ft Quaternery chlorides 46,000 lb Sodium hydroxide 48,000 lb 50% sodium hydroxide 3., 500 gal.

93% sulfuric acid 3, 500 gal.

(l)The chemicals listed above pass by the Dresden site with a minimum frequency of 10 times per year. Refer to Section 3 of this report for further discussion of this subject.

< 2 >c1osest. potential approach of the transport vehicle to the Dresden site on a given highway.

())Wherever multiple container sizes of the same chemical are transported

( )on a given highway, the quantity of the largest container is provided.

4 Standard type gas bottles

( 5 >This is the. volume of gas each* liquid would have at standard temperature and pressure.

TABLE C-6 REFERENCES

l. Waterborne Commerce of the United States, 1978, U.S. Army Corps of Engineers

2. Telephone conversation between B. Burdick and R. MacLauchlin, u.s. Army Corps of Engineers, 9/14/81 (3320)

3. Telephone conversation between B. Burdick and K. Salo,. Dow Chemical, 9/30/81 (3478)

4. Telephone conversation between D. Semon and J. Labeda, Liquid Air Corporation of North America, 9/9/81 (3297)

5. Telephone conversation between D. Semon and J~ Quinn, Fisher-Kalow, 9/18/81 (3405)

6. Telephone conversation between D. Semon and R. Wawrznyiak, Alexander Chemical, 9/18/81 (3404)

7. Telephone conversation between D. Semon and P. Hackett, Liquid Air Corporation of America, 9/25/81 (3399)

8. Telephone conversation between D. Semon and c. Desanty, Airco, 7/22/81, 8/24/81 (3022, 3223) 9* Letter from Alumax, 8/11/81 (3153)

10. Telephone conversation between D. Semon and W. Burch, Alumax, 8/18/81 (3184)

11. Letter from A.P. Green Refractory, 8/31/81 (3263)

12. Telephone conversation between D. Semon and B. Gielisk, A.P. Green Refractory, 10/5/81 (3524)

. 13. Letter* from Arrnack, 8/31/81 (3254)

14. Telephone conversation between D. Semon and K. Brandmire, Armack, 10/12/81 (3519)

15. Telephone conversation between D. Semon and L. Bols, farm, 7/21/81 (3012)

16. Telephone conversation between D. Semon and W. Carmack, Cardox, 7/22/81, 8/24/81, 9/21/81 (3023, 3222, 3367)

17. Telephone conversation between D. Semon and R. Wine, Collins Station, 7/15/81, 7/20/81 (2980, 3015)

18. Telephone conversation between D. Semon and R. Still, Collins Station, 7/20/81 (3014)

19. Telephone conversation between D. Semon and J. IX>llinger, farm, 7/22/81 (3021)

20. Telephone conversation between B. Burdick and P. Ottison, Dravo-Mechling, 9/21/81 (3357)

21. Telephone conversation between B. Burdick and R. Cardillo, Exxon Chemical Americas, 9/24/81 (3386)

22. Letter from General Electric, 8/17/81 ( 3189)

23. Telephone conversation between D. semon and o. Sturnan, Hydrocarbon Transport, 8/24/81, 9/28/81 (3225, 3441)

24. Telephone conversation between D. Semon and M. Young, Mid-America Pipeline, 8/10/81, 9/14/81, 10/2/81 (3124, 3346, 3518)

25. Telephone conversation between D. Semon and D. McCoy, Minooka Wastewater Facility, 7/13/81 (2966) ,-

26. Telephone conversation between D. Semon and C. Cassidy, Midwestern Gas Transmission, 8/24/81, 9/28/81 (3221, 3442)

27. Letter from Midwestern Gas Transmission, 8/25/81 (3237)

28. Letter from Mobil Chemical, 9/22/81 (3393)

29. Letter from Natural Gas Pipeline Company of America, 9/11/81 (3353)

30. Letter from Northern Illinois Gas, 9/2/81 (3325)

31. Telephone conversation between D. Semon and E. Gruber, Northern Illinois Gas, 10/5/81 (3521)

32. Telephone conversation between D. Semon and C. Hendrickson, Northern Illinois Gas, 10/5/81 (3522)

33. Telephone conversation between B. Burdick and J. Basil, Reichhold Chemical, 9/8/81 (3280j

34. Letter from Elgin, Joliet, and Eastern Railway, 8/21/81 (3214)

35. Telephone conversation between o. Semon and T. Bray, Elgin, Joliet, and Eastern Railway, 9/25/81 (3403)

36. Telephone conversation between B. Burdick and T. Bray, Elgin, Joliet, and Eastern Railway, 9/25/81 (3396)

37. Letter from Illinois Central Gulf Railroad, 8/17/81 (3262)

38. Telephone conversation between M. Dunn and c. Bossard, Illinois Central Gulf Railroad, 10/2/81 (3443)

39. Telephone conversation between D. Semon and J. Mendalbaum, u.s. Interstate Commerce Commission, 8/19/81 (3188)

40. Telephone conversation between B. Burdick and J. Nalevanko, Materials Transportation Bureau, Department of Transpor-tation, 8/12/81 (3151)

41. Telephone conversation between D. Semon and R. Powell, Shady Oaks Park, 7/14/81 (2963)

42. Telephone conversation between o. Semon and R. Kraus, Union Carbide, 8/18/81, 10/5/81 (3185, 3523)

43. Telephone conversation between D. Semon and L. Rapp, Bob Rapp's Dock, 7/15/~l (2972)

44. Telephone conversation between B. Burdick and R. Craig, Baltimore and Ohio Railroad, 8/17/81, 9/1/81 (3179, 3248)

45. Telephone conversation between B. Burdick and w. Brodsky, Atcheson, Topeka, and Santa Fe Railroad, 9/8/81 (327.4)

46. Telephone conversation between D. Semon and G. Wimberly, Durkee Foods, 10/26/81 (3527)

47. Letter from Mobil Oil Corporation, 8/21/81 (3199)

48. Letter from Northern Petrochemical Company, 8/19/81 (3201)

49. Telephone conversation between B. Burdick and D. Harmer, Dow Chemical, 9/18/81 (3359)

50. Telephone conversation between D. Semon and John Gann, Calgon, 11/13/81 (3609)

APPENDIX D RADIOLOGICAL ANALYSIS FOR CONTROL ROOM HABITABILITY FOLLOWING A DBA-LOCA

A. INTRODUCTION The following analysis was performed in accordance with the guidance of NUREG 0737, Item III.D.3.4 to determine compliance with the radiological requirements of General Design Criterion 19 and Standard Review Plan (SRP) 6.4. The loss-of-coolant accident (LOCA) was considered in the analysis to be the radiological design basis accident (DBA). Furthermore, main steam isolation valve (MSIV) leakage at the technical specification limit was assumed for the analysis.

The results of this analysis are considered conservative.

Several natural mechanisms will reduce or delay the radioactivity prior to release to the environment. However, credit was taken only for iodine plateout on surfaces of the steam lines and condenser and radioactive decay prior to release. These mechanisms are discussed in Section E.

B. METHODOLOGY The guidelines given in SRP 6.4 (Reference l) and Regulatory Guide 1.3 (Reference 2) have been used with the exception of the X/Q for the control room and plateout of iodines during trans-portation within pipes. *Realistically, the components of main steam lines and the turbine-condenser complex, though nonsafety grade, would remain intact following a DBA-LOCA. Therefore, plateout of iodines on surfaces of main steam lines and the turbine-condenser complex is expected. Atmospheric dispersion factors are based on the Halitsky Methodology from Meteorology and Atomic Energy 1968, -as discussed in Section D.

C. ASSUMPTIONS AND BASES Regulatory Guide 1.3 has been used to determine activity levels in the containment following a DBA-LOCA. Activity releases are based on a containment leakage rate of 1.6% per day. Table D-1 lists the assumptions and parameters used in the analysis and dose point locations. The majority of the containment leakage ._

will be collected in the reactor building and exhausted to the atmosphere through the 99% efficient SGTS filters as an elevated release from the main stack. However, there are certain release pathways from the containment which will bypass the SGTS filters.

The bypass leakage has been quantified by assuming that all MSIVs leak at the technical specification limit of 11.S scfh per main steam line. Based on this assumption, a total leakage for all steam lines together would be 46 scfh (0. 7667 scfm).

D-1

Radioactivity leaking past the isolation valves could be released through the outboard MSIV stems into the steam tunnel, or con-tinue down the steam lines to the stop valves and into the turbine-condenser complex. Leakage into the steam tunnel is exhausted by the SGTS filtration system, thus eliminating it as a bypass pathway. Leakage down the steam lines is subject to plateout and delay within the lines. Reference 3, Section 5.1.2 discusses iodine removal rates which can be applied to calculate plateout on the piping and turbine condenser surfaces. Elemental and particulate iodine decontamination factors of over 100 can be calculated for small travel distances and large travel times down the steam lines, considering the small volumes of leakage which leak past the valves.

The credit for plateout and holdup within steam lines and the turbine-condenser complex has been taken by dividing them into three different volumes. The first volume consists of steam lines between the inboard and outboard isolation valves, the second volume consists of steam lines between the outboard iso-lation valves and the turbine stop valves, and the third volume includes the steam lines after the turbine stop valves and the turbine-condenser volume complex. Conservatively, failure of an inboard isolation valve in one main steam line has been consi-dered. The activity leaking from the primary containment travels through, and mi~es well within, each volume prior to release to the environment from the turbine-condenser complex. The removal rate for iodine due to plateout within each volume is based on the estimated surface area and the methodology given in Refer-ence 3, Section s.1.2. These removal rates are only applied to elemental and particulate iodines. The removal of organic iodine through plateout is not considered. It was assumed that the bypass leakage is collected in the steam line turbine-condenser volume complex from which it will leak at 1% of the turbine- .

condenser volume per day. This leak rate "is consistent with t.he assumptions used for the control rod drop accident in SRP 15.4.9 (Reference 4). This assumption is conservative, because the volumetric leakage out of the condenser would be approximately the same as the inleakage and the 1% leak rate per day out of the tur.bine-condenser volume is higher than the leak rate into the steam lines from the drywell. Furthermore, the bypass leakage will be cooling and condensing as it travels down the lines.

Leakage within the turbine building would be exhausted by the heating, ventilating, and air conditioning (HVAC) system if it were working. Additional plateout on ductwork, fans, and unit coolers would further minimize the iodine releases. Should the HVAC system not be working, then any bypass leakage would tend to collect in the building and be subject to additional decay and plateout. Leakage from the turbine building into the control room is minimized by the separate HVAC systems and by maintaining the interconnecting doors in their normally closed positions.

Ir-2

The control room pressurization system ensures that leakage is from the protected area towards the other parts of the building, further minimizing the possibility of contaminating the protected areas. A positive pressure is maintained in the main control room by introducing 2,000 cfm of outside air through a 99% effi-cient filtration system.

The activity which enters the main control room may be the result of bypass leakage, standby gas treatment system (SGTS) exhaust in the outside air, or both, depending on wind direction. Because of the locations of these sources with respect to the control room HVAC intake, it is possible for the intake to be exposed to activity from both sources at the same time. Because the SGTS exhaust is elevated, the concentrations from this source at the intake will be less than those due to bypass leakage. This analysis conservatively assumes that the activity concentration at the intake is due to concurrent bypass leakage and chimney releases for the duration of the event.

D. ATMOSPHERIC DISPERSION FACTOR (X/Q)

The following discussion is an explanation of the reasons for the use of the Halitsky X/Q methodology and a value of K = 2, instead of the Murphy methodology (Reference 5) which. SRP 6. ~ suggests as an interim position.

Historically, the preliminary work on building wake X/Q's was based on a series of wind tunnel tests by J. Halitsky, et al.

Hali tsky summarized these results in Meteorology and Atomic Energy in 1968 (Reference 6). In 1974, K. Murphy and K. Carnpe of the NRC published their paper based on a survey of existing data.

This X/Q methodology, which presented equations without derivation or justification, was adopted as the interim methodology in SRP 6.4 in 1975. Since then, a series of.actual building wake X/Q measurements have been conducted at Rancho-Seco (Reference 7) and several other papers have been published documenting the results of additional wind tunnel tests.

In Reference S, Murphy suggested the following equation for the calculation of X/Q X/Q = Kc /AU where Kc = K + 2 K = 3/ cs;d >i.

4 A = Cross-sectional area of the building u = Wind speed*

D-3

This formulation was derived from the Halitsky data in Figure 37 of Reference 5 from Murphy's paper. The Halitsky data were from wind tunnel tests on a model of the EBR-II rounded (PWR type) containment and the validity of the data was limited to 0.5<s/d <3 (Reference 6, Section 5.5.5.2). The origin and reason for the +2 in K + 2 is not known. All other formulations use K only, and for the situation where K is less than 1, the use of K + 2 imposes an unrealistic limit on the X/Q.

For the Dresden plant, the building complex is composed of square-edged buildings and not a round-topped cylindrical con-tainment as was used in the Halitsky experiments. For an HVAC intake located near the south wall of the control building at elevation 549'-0", the intake will be subject to a building wake caused by a combination of the reactor building and the turbine building for any bypa$s leakage escaping from the turbine building. There will be no reactor building bypass leakage because the building is kept at a negative pressure by the SGTS which exhausts to the main chimney.

Because the Murphy methodology could not be applied, a survey of the literature was undertaken. It was found that the Halitsky wind tunnel test data (Reference 6, Section 5.5.5) conservatively overestimated K values *by factors of up to possibly 10." Given this conservati~m, it was felt that the use of a reasonable K value from the Halitsky data on square-edged buildings shouldc be acceptable. A review of Figure 5.27 from M&AE (Reference 6) resulted in K values in the 0.5 to 2 range. A value of K = 2 was chosen tocget a X/Q f~r the control :oom. A buildi~g 8ross-sectional area of 1,550 m was conservatively used. This cor-responds to a projec~ed area of one reactor building above grade.

The use of a 1,550 m area is very conservative because both the _

reactor buildings are adjacent to each other and the combined projected area *would be larger than the value used. Information from other sources, as indicated below, has also shown that this should be a conservative value.

1. In a paper by D. H. Walker (Reference 8), control room X/Q' s were experimentally determined for floating power plants in wind tunnel tests. Different intake and exhaust combi-nations were considered. Using the data for intake 6 2gd stack A e~gaust (Reference 8), X/Q values of 1.77 x 10 and 2.24 x 10 were found after adjusting the wind speed from 1.5 m/sec to 1 m/sec. These values are approximately two order-of-magnitudes lower than the conservatively calculated value for Dresden.

D-4

2. In a wind tunnel test by P.N. Hatcher (Reference 9), a model industrial complex was used to test dispersions due to a wake. Data obtained from these tests show that K has a value less than 1, and decreases as the test points are moved closer to the structure. In a study to determine optimum stack heights, R.N. Meroney and B.T. Yang (Ref-erence 10) show that for short stacks (6/5 of building height), K reaches a value of approximately 0.2 and decreases 81oser to the building. They concluded that the Halitsky methodology was *ov~rly conservative.* These recent experimental tests show that K = 2 used to determine the X/Q for Dresden is a conservativecestimate by at least a factor of 2 and possibly by 10 or more.

3. Field tests were made on the Rancho-Seco facility (Ref-erence 7), and X/Q values were obtained. The data indicate that the use of K = 2 is conservative.

c It was concluded that sufficient data and field tests exist to give a reasonable assurance that the chosen X/Q is a conservative one, over and above the conservatism implied by using the fifth percentile wind speed and wind direction factors.* Based on the above discussion, the following equation is used in the calcu-lation of X/Q value*s.

X/Q = 2/AU E. MECHANISMS FOR REDUCING IODINE RELEASES The following mechanisms could result in significant quantities of iodine being removed before they are released to the environ-ment. However, numerical credit for the plateout mechanisms is the only credit taken in the calculation of radiological consequences.

1. DRYWELL SPRAYS, SUPPRESSION POOL TO AIR PARTITIONING, AND CONDENSATION EFFECTS

Though manually operated, the drywell sprays will reduce the iodine source term if actuated. Even without the spray system, condensation will occur in the drywell and suppression chamber.

The iodines in the air and suppression pool are expected to reach equilibrium due to this phenomenon. Because the iodines have a preference to stay in water due to the equi-librium partition factor of over 400 established by the physical conditions in the containment, the iodines avail-able for release by air leakage will be reduced signif i-can tly. In addition, recent investigations after TMI (NSAC-14, Workshop on Iodine Releases in Reactor Accidents) have indicated that the iodine release assumption may be exces-sively conservative. Most of the iodine may be released as cesium iodide instead of elemental iodine. The cesium iodide has a much higher solubility and ability to plateout than elemental iodine.

D-5

2. PLATEOUT Although there is an implied factor of 2 iodine plateout in Regulatory Guide 1.3 source term, experimental evidence and the experience at TMI indicates that significantly larger plateout factors are common. The plateout removal constant used in this analysis is based on the lowest deposition velocity quoted in Reference 3. The other data quoted in Reference 7 indicate that the deposition velocities could be higher by a factor of 4, which would tend to increase the plateout.

3. REMOVAL THROUGH VALVES AND LEAKAGE HOLES Because the bypass leakage paths are through minute holes in valves and valve seats, the leakage will be subjected to filtration effects. Larger particulates could tend to piug the leak paths (Reference 11).

4. CONDENSATE WITHIN PIPES Condensation will occur within the pipes when the pipes cool down to ambient temperature. This could result in removal of iodines and particulates from the gas phase.

F. RESULTS The calculated radiation doses' are given in Table D-2 and are found to be within the guidelines of General Design Criterion 19 and SRP 6. 4 *

D-6

REFERENCES

1. Standard Review Plan 6.4, Habitability Systems, Rev l

2. Regulatory Guide 1.3, Assumptions Used for Evaluating the.

Potential Radiological Consequences of a Loss-of-Coolant Accident for Boiling Water Reactors, Rev 2, June 1974

3. NUREG/CR-009, *Technilogical Basis for Models of Spray Washout of Airborne Contaminants in Containment vessels,"

A.K. Posta, R.R. Sherry, P.S. Tam, October 1978

4. Standard Review Plan 15.4.9, Spectrum of Rod Drop Accidents

( BWR), Rev 1

s. K.G. Murphy and K.M.* Campe, *Nuclear Power Plant Control Room ventilation System Design for Meeting General Design Criterion 19,* 13th AEC Air Cleaning Conference

6. D.H. Slade, ed., Meteorology and Atomic Energy, TID 24190 (1968)

7. G.E. Start, J.H. Cate, C.R. Dickson, N.R. Ricks, G.H. Ackerman, and J.F. Sagendorf, *Rancho-Seco Building Wake Effects on Atmospheric Di ff us ion," NOAA Technical Memorandum, ERL ARL-69 (1977)

8. D.H. Walker, R.N. Nassano, M.A. Capo, 1976, "Control Room Ventilation Intake Selection for the Floating Nuclear Power Plant," 14th ERDA Air Cleaning Conference

9. R.N. Hatcher, R.N. Meroney, J.A. Peterka, and K. Kothari, 1978, *oispersion in the Wake of a Model Industrial Complex,"

NUREG 0373

10. R.N. Meroney and B.T. Yang, 1971, *wind Tunnel Study on Gaseous Mixing bue to various Stack Heights ~nd Injection Rates Above an Isolated Structure,* FDDL Report CER 71-72RNM-BTY16, Colorado State University

11. H.A. Morewitz, R.P. Johnson, C.T. Nelson, E.v. Vaughan, C. A. Guderjahn, R. K. Hillard, J. D. McCormack, and A. K. Posta,

Attenuation of Airborne Debris from Liquid-Metal Fast Breeder Reactor Accident,* Nuclear Technology, Volume 46, December 1979 *

D--7

TABLE D-1 LOSS-OF-COOLANT ACCIDENT PARAMETERS TABULATED FOR POSTULATED ACCIDENT ANALYSES Design Basis Assumptions I. Data and Assumptions Used to Estimate Radioactive Source from Postulated Accidents A. Power level, MWt 2,527 B. Burnup NA

c. Fission products released from fuel (fuel 100%

damaged)

D. Iodine fractions Organic 0.04 Elemental 0.91 Particulate o.os II. Data and Assumptions Used to Estimate Activity Released A. Primary containment leak rate, %/day 1.6 B. Volume of primary containment, cu ft 2.7SE+S

- C.

D.

E.

F.

G.

Secondary containment release rate, %/day Leak rate through MSIV, scfh Number of main steam lines Leak rate from turbine condenser complex,

%/day Volume and surface area (all four steam 100

11. 5 4

1. 0 Ft 3 lines)

Between inboard and outboard MSIV 176 470 .

Outboard and turbine stop valves 761 1,693 Turbine condenser complex 1. 7E+S 6.SE+S H. Deposition velocity for iodines, cm/sec Particulate 0.012 Elemental 0.012 Organic o.o I. Valve movement times (See Note)

J. SGTS adsorption and filtration efficiencies, %

Organic iodines 99 Elemental iodine 99 Particulate iodine 99

Table D-1 (continued)

Design Basis Assumptions 3

Dispersion Data, sec/m A. Control room wake X/Q for time intervals SGTS of Bypass Leak (Chimney) 0 to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months l.29E-3 7.0E-4*

2 to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 1. 29E-3 6.4SE-6 8 to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7.61E-4 3.81E-6 1 to 4 days 4.84E-4 2.42E-6 4 to 30 days 2.13E-4 1. 07E-6

O to 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months fumigation conditions assumed according to Regulatory Guide 1. 3 IV. Data for Control Room 3

A. Volume of control room, ft 1. 04E+S B. Filtered intake, cfm 2,000

c. Efficiency of charcoal adsorber, % 99 D. Efficiency of HEPA, % 99.9 E. Unfiltered inleakage, cfm 10 F. Recirculation flowrate o.o G. Occupancy factors:

0 to 1 day . 1. 0 l to 4 days 0.6 4 to 30 days 0.4 Note.: The MSIV movement times are not applicable to the analysis because the valves will close before any significant fuel failures occur.

The control room HVAC intake valve movement times are not applicable because the calculated doses assume an unfiltered outside air intake of 2,000 cfm for the first 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months post-LOCA

TABLE D-2 DBA-LOCA RADIOLOGICAL CONSEQUENCES Doses (Rem)

CONTROL ROOM Thyroid Skin Whole-Body

1. Bypass Leakage

a. Activity inside control room 3.04 4. 77E-l 1. SSE-2

b. Plume shine . 2. 03E-3

c. Direct shine 1. OlE-1

2. Stack Release.

a. Activity inside control room 1. 20E+l 2.35 1. 75E-l

b. Plume shine 1. 98E-2 TOTAL CONTROL ROOM DOSES 1. SOE+l 2.02 3.16E-l Note: The values provided above represent 30-day integrated doses.. The doses are calculated assuming an unfiltered outside air intake of 2,000 cfm for the first 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months post-LOCA.

At 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the con-trol room operators are assumed to remote manually activate the charcoal filtration unit *

ML17194A372

Text

1.0 INTRODUCTION

1.0 INTRODUCTION

SUMMARY

1.0 INTRODUCTION

1.0 INTRODUCTION

Navigation menu

Search