ML20042A505
| ML20042A505 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 01/31/1982 |
| From: | STONE & WEBSTER ENGINEERING CORP. |
| To: | |
| Shared Package | |
| ML20042A498 | List: |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-3.D.3.4, TASK-TM B1-1392920-2, NUDOCS 8203230503 | |
| Download: ML20042A505 (14) | |
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d.
CONTROL ROOM HABITABILITY STUDY (SUPPLEMENT TO 1980 ONSITE CONTROL ROOM HABITABILITY STUDY)
NORTH ANNA POWER STATION UNITS NOS. 1 AND 2 PREPARED FOR VIRGINIA ELECTRIC AND POWER COMPANY JANUARY 1982 APPROVED BY:
/
Project Engineer DivisionHea[
w /~~L Engineering Management STONE & WEBSTER ENGINEERING CORPORATION BOSTON, MASSACHUSETTS 8203230503 820315 PDR ADOCK 05000339 P
PDR lu
CONTROL ROOM HABITABILITY STUDY FOR 1
(SUPPLEMENT TO 1980 ONSITE CONTROL ROOM HABITABILITY STUDY)
NORTH ANNA UNITS 1 AND 2
1.0 INTRODUCTION
Compliance with General Criterion 19 of Appendix A to 10CFR50 requires a control room design which allows a nuclear power plant to be safely operated or shut down under design basis accident conditions.
In this regard, section III.D.3.4 of NUREG-0737 requires licensees to assure the protection of the control room opera'. ors from the effects of outside accidental releases of toxic or hazardous chemicals. This is accomplished by demonstrating compliance with the criteria outlined in Nuclear Regulatory Commission (NRC) Regulatory Guides 1.78 (Rev. 0) and 1.95 (Rev. 1) and Standard Review Plan (NUREG-0800) Sections 2.2.1 (Rev. 2), 2.2.2 (Rev. 1),
2.2.3 (Rev. 2), and 6.4 (Rev. 2).
A demonstration must include the results of an analysis which determines control room concentrations of toxic vapors resulting from a postulated accidental release. This release can occur from toxic chemicals stored either on the site or anywhere within a 5-mile radius of the control room and from mobile sources (i.e., truck, rail, barge shipments) within 5 miles of the control room. This report provides a description and the results of such an evaluation performed for the North Anna Units 1 and 2 control room for various stored chemicals at the offsite designated storage Area A B1-1392920-2
. o 0
(located 2,800 ft from the control room), Area B (located 2,300 ft from I
the control room), Area C (located 1,350 ft from the control room), and Area D (located 500 ft from the control room).
The evaluation involves the calculation of a toxic vapor concentration time history at both the outside intake and inside the control room, for each toxic chemical which could be stored at the aforementioned storage areas.
The calculation takes into account the control room characteristics, type of potential chemical, its physical parameter, and the design basis meteorology which will conservatively result in the highest hypothetical control toxic vapor concentrations. The resulting toxic vapor concentrations calculated inside the control room are then compared with the most recent human toxicological data available to assess the potential for operator incapacitation.
2.0 DETERMINATION OF CHEMICAL T0XICITY Table I lists all potential hazardous chemicals (obtained from VEPCO letter N08.2-S07-039 and SWEC letter N19-VOL-521) at the designated storage areas.
Some of the materials do not require evaluation since they are stored in a solid form that does not emit vapors, stored in a liquid form which evaporates at an extremely low rate (e.g., sodium hydroxide), or were analyzed in an earlier toxic chemical study (see SWEC letter NAS-12,356 dated May 2, 1980). At the present time, chlorine is not stored at storage Area A; thus, a maximum allowable storage quantity was considered in this B1-1392920-2 2
analysis. Table II lists all of the toxic chemicals for which habitability evaluations must be performed.
The criteria for determining chemical toxicity and establishing limits for habitability determinations are derived from regulatory guidance. According to Regulatory Guide 1.78 (Rev. 0), the toxicity limit of a chemical is the maximum concentration that can be tolerated by an average person for 2 minutes without physical incapacitation (i.e., severe coughing, eye burn, severe skin irritation). Standard Review Plan Section 6.4 (Rev. 2) states that acute effects should be reversible within a short period of time (several minutes without benefit of medication other than the use of a self-contained apparatus). The acute toxicity limits listed in Regulatory Guide 1.78 (Rev. 0) are used in this analysis when available. However, most of the chemicals considered in this study were not assigned acute toxicity limits by Regulatory Guide 1.78 (Rev.0).
In those cases, conservative limits were obtained from other authoritative sources (References 2-3).
Nonguideline toxicity limits are based on the highest concentrations which produce no effects, or minor irritation not affecting mental alertness and physical coordination.
In many cases, the available toxicity information is not based on the 2 minute exposure time specified by Regulatory Guide 1.78, so extrapolation is necessary. Therefore, a 15 minute exposure time was assumed, which is the exposure time used by the American Conference of Governmental Industrial Hygienists (ACGIH), (Reference 3), to determine the Short Term Exposure Limit (TLV-STEL). This concentration protects a worker from irritation, chronic or irreversible tissue change, or narcosis of l
B1-1392920-2 3
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sufficient degree to increase accident proneness, impair self-rescue, or materially reduce work efficiency.
The TLV-STEL is used in the absence of Regulatory Guide 1.78 (Rev. 0) toxicity limit data.
In the absence of specific chemical mixture in'ormation, the more conservative workplace limits or Threshold Limit Value (TLV) suggested by ACGIH are used. Toxicity limits appearing in Table III are taken from ACGIH or determined according to ACG1H guidance.
3.0 CONTROL ROOM HABITABILITY DETERMINATION The effects of an accidental release of each of the chemicals listed in Table II on control room habitability were evaluated by calculating toxic vapor concentrations inside the control room as a function of time following the start of the accident. The calculation was performed using the methodology outlined in NUREG-0570, entitled " Toxic Vapor Concentrations in the Control Room Following a Postulated Accidental Release," along with the assumptions described in Regulatory Guide 1.78 (Rev. 0).
In a posculated accident, the entire contents of the largest single chemical storage container are released to the atmosphere, resulting in a toxic vapor cloud and/or plume which is conservatively assumed to be transported by the wind directly toward the Units 1 and 2 control room main fresh air intake.
The formation of the toxic cloud or plume is dependent on the physical properties of the chemical and the ambient environmental characteristics.
The entire amount of a chemical stored as a gas is treated as an B1-1392920-2 4
i S
l instantaneous puff or cloud which has a finite volume determined from the quantity and vapor density of the stored chemical. For a toxic chemical stored as a liquid with a boiling point below the ambient dry-bulb temperature, an instantaneous puf f due to flashing (rapid gas formation) of some fraction of the stored quantity is first formed. The remaining liquid forms a puddle which quickly spreads into a 1 centimeter thick layer on the ground, subsequently vaporizing and forming a ground-level vcpor plume. For a stored liquid chemical that has a high boiling point (i.e., greater than outside ambient dry-bulb temperature), a 1 cm thick puddle is formed which evaporates by forced convection with no flashing taking place.
All calculations were performed by the Stone & Webster Engineering Corporation " VAPOR" computer model which requires input information on the ph;"ical properties of the chemical, control room HVAC parameters, meteorology, distance from the spill to the control room intake, quantity of the chemical released and associated toxicity limits.
For the North Anna Power Station, the following Units 1 and 2 control room parameters were used as input to the VAPOR program:
3 3
Control room air volume = 109,000 ft (3,087m ).
Normal fresh air intake = 2,800 cfm (1.32 cm/s).
Meteorological conditions assumed for the calculations were as follows:
Pasquill stability class - F (moderately stable).
B1-1392920-2 5
Horizontal wind speed = 2.24 mph (1.0 m/s).
Ambient dry-bulb temperature = 97.0'F (36.14*C).
It was also assumed that the spiil and control room fresh air intake elevations are at ground level, and the puff or plume centerline con-centration impr. cts directly on the main fresh air intake.
l The resultant maximum chemical vapor concentration and related toxicity limit for each toxic chemical inside the Units 1 and 2 control room are presented in Table III.
4.0 CONCLUSION
S AND RECOTfENDATIONS As a result of this study, all of the additional hazardous chemicals with the exception of chlorine and ammonia hydroxide identified in this analysis do not impare the Units 1 and 2 control room habitability if accidentally released from their storage containers in either Areas A, B, C, or D.
The toxic chemicals chlorine and ammonia hydroxide are allowed to be stored at designated storage Area A under the present RCRA license.
However, as stated in Section 2.0 of this report, no chlorine is presently being stored at this location.
If at some future date chlorine were to be stored at Area A, the maximum chlorine quantity within a container should not exceed 250 lb.
In addition, the maximum ammonia hydroxide quantity within a container should not exceed 45 gallons. These quantity limits will allow B1-1392920-2 6
E the safe storage of chlorine and ammonia hydroxide at Area A without resulting in a control room habitability problem if accidentally released from their storage containers.
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B1-1392920-2 7
TA3LE I HACARDCUS CHEMICALS LCCA 23 AT OFFSITE STORAGE AREAS STCRAG STCRAG STCRAG STCRAG AREAS A*
AREAS 3
AREAS C
AREAR 3
Methyl Ethyl Ketone Methyl Ethyl Ketone Varsol Mineral Spirits Sodium Hydroxide
- Acetone Blend No. 2 Thinner No. 3819 Aamonium Hydroxide
- 3 pexy 3 inner Thinner Nc. 3871 Methyl Ethyl Ketone 1,1,1,-Trichlorceth.
Tetracnior: ethylene Thinner No. 4093 No. 2200 Epexy hinner Methanoi Trichlercethylene Thinner No. 4C93 Hydra:ine (30 gal)
- Methylene Chloride Blend 33-Carboline 8254 TRAM 1,1,1-Trichloroethane Epoxy hinner No. 3871 Solvent K Chicroben:ene Epoxy Cleane: No. 31004 Gases (Carbon dioxide, 1,1,2-Tri:nicro-1,2,2-Xylol Mitrogen, etc.)"
Trifluoroethane C-cichlorchen:ene Trichicrofluoromethane Xylene 5thyl Acetate Ethyl Eenzene Ethyl Ether N-Butyi Alecnol Cyc1chexanone Methanol Toluene Methyl Isobutyl Ketone Carbon 7. sulfide
- sobutanel Alcohol (Denatured)
Amino Acid Anmenia Asbestos Cement Sealing Ocepeund Chlorine Flame, Saf ety 'amo Fuel Freen HTH (Perchloren)
Hydra:ine
+ Some of these :hemicals at Laccuer,.:aint, Varnish Sterage Facility A de no yet Mercury (Metali:)
reside there. However, :hev Naphtha '3 inner) are licensed under the Invir-Polychl:rinated Eiphenyls enmental ? tection Agency's Petassium : / :cxide Resources Conservati:n anc Turpentine
?.ecovery Act, anc. vere presumec Vinyl *.iqui:
- ultimately exist at that Max *icuid
- cation. All cuantities are Weci (Cotton) stated in la
- 9-31?-Vol-521, dated 12/11/S1.
- These chemicals were analv:ed in an earlier toxi: chemical recort see letter NAS-12,356 dated 5/2/80.
TABLE II HAZARDCUS CHEMICALS ANALYZED FOR 7.c!R POTENTIAL EFFECT CN TE CONTROL ROCM CPERATCR C'd MICAL Area A Methyl Ethyl Ketone Acetone Epoxy Thinner No. 4093 Tetrachloroethylene Trichloroethylene Methylene Chloride 1,1,1 - Trichloroethane Chlorobenzene 1,1,2 - Trichloro - 1,2,2
- Triflurcethane (Freon 113) 0 - Dichlorobenzene Trichlorofluoromethane (Freon 11)
Xylene Ethyl Acetate Ethyl Benzene Ethyl Ether N-Butv1 Alcchol Cyclohexanone Methanol Toluene Methyl Isobutv1 Ketone Carbon Cisulfide Isobutanol Pyridine Anunonia Alcohol (Cenatured)
Chlorine Hydrazine Mercury (Metallic)
Potassium *+f roxide d
Turpentine Area 3 Methyl Ethyl Ketone Cleaner No. 31004 Thinner No. 3871 Thinner No. 4093
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TABLE :: Conti=ed HAZARDCUS CHEMICALS ANALYZED FOR THEIR 70 TINT!AL. cr~s CN Tr2 CC;GOL ROCM CPERATCR CHEMICAL Area O Xylene (Xylol)
Thinner No. 3871 Varsol Mineral Spirits Thinner No. 3819 Methyl Ethyl Ketene Thinner No. 4093 31end No. 33 - Carboline Epoxy Cleaner No. 31004 Area 0 1,1,1 - Trichl:rcethane Methanol 8254 TRAM Solvent K l
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w CONTROL RCCM APEA - A Maxi =um Centrol Texicity Chemical Roem Cenegn::ati:n Limit It::ed (c/b4)
(o/b3)
Methyl Ethyl Xet:ne 3.79E-3 0.90(2)
Ace :ne 2.27E-2 3.00(3)
To::acaler: ethylene 7.07E-3 1.00(3)
Tri:nler: ethylene 3.025-2 0.80(3)
Me:nylene Ohloride 3.96E-2 0.87(3) 7:i:hloroethane 2.38E-2 2.38(3)
Ohl::: ben:ene 3.202-3
- 0. 35(4)
- .:sen 113 5.945-4 9.50(3)
Ci:nl::: ben:ene 1.57E-3 0.30(4) 2:sen 11 6.115-2 7.00(3)
Xviene 5.39E-3 0.70(4)
Ethyl Ace:a a 1.692-2 1.40(4)
E nyi Een:ene 3.20E-3 0,.55 / 3)
Ethyl Ether 2.10E-2 1.50(3)
?!-Eutyi Al:chel 2.25E-3 0.15(4)
Cyc1:nexanene 2.78E-3 0.20(4)
"etnanel 1.33E-2 0.50(1) 7:1uene 7.18E-3 0.80(2)
Ye:nyl laccu:y1 Xe::ne 4.21E-3 0.51(3)
!ar:en Cisulfide 3.88E-2 1.30(2) 1scou:anel 6.98E-3 0.20(3)
Pyridine 2.302-3 0.03(3)
Amm:ni. Hydroxide 1.10E-2 0.027(3)
A*::ncl, Cenatured 4.885-3 1.90(4)
My::a:ine 2.75E-3 0.12(2)
"er:ury 6.485-4 0.015(3)
?::sssium Myd::xide 1.81E-4 0.0C2(2) 7 pentine 4.285-4 0.34(3) 5: xy Thinne #4093 3.965-4 0.56(4) l l
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TAELE III Conti=ued PREDICTED T0XIC VAPCR CCPCENTRATICNS INSIE THE UNIT 1 AND 2 CCNTRCL RCCM AREA-B Maximum Control Toxicity Chemical Room Concent atien Limit D
Stered (c/m )
(c/m )
'Aethyl Ethyl Ketone 2.09E-2 0.90(2) 31end.'ic. 2 minner 4.22E-2 0.32(4) 3 inner No. 3871 1.54E-2 0.40(4)
Tninner No. 4093 1.90E-3 0.56(4)
AREA-C Xylene 1.77E-2 0.70(4) 2 inner !!o. 3871 9.33E-3 0.40(4)
Varsol Mineral Spirits 1.38E-3 1.60(2) 3 inner No. 3819 9.46E-3 0.46(4)
Methyl Ethyl Ketene 2.06E-3 0.90(2)
Thinner No.1093 1.16E-3 0.56(4) 31end 33 - Carboline 2.31E-3 0.35(4)
Epoxy Cleaner No. 31004 3.17E-5 0.32(4) l l
AREA-D
,1,1-Trichlercethane 4.39E-1 2.38( 3)
Methanel 2.45E-1 0.50(1) 1.05(3) 0.77/4 3254 RAM 4.14E-1
)
Solvent g 1.79E-2 (1).
U.S. Atomic Energy Commission, Regulatory Guide. 74. " Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release" (1974).
(2).
Patty, F. A. (ed.), " Industrial Hygiene and Toxicology," Vols. I and II.
Interscience Publishers, New York, 1963 and 1981.
O.
TLV-STEL, Documentation of the Threshold Limit Valves, Fourth Edition, 1980 by the American Conference of Governmental Industrial Hygienists.
Cincinnati, OH.
TLV. ibid
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3s3.5 ACTION RECORD SHEET N ~ VO I - 8F 3 Assigned To:
Letter No.
Letter
Title:
CeTrze l Rom M AE T* W 1: Tv - SpolenTAl 3Mw th kWWA. hCW ON DTA.N O
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If Not Is completion of this form necessary Yes No Applicable, Initial Write in N/A" Specification Approval Yes No Initial when Completed SAR Requirements reviewed: (E.C. Regulatory Requirements, j
design bases, etc.)
b,/ 8 SAR Change Notice filed, if required?
Files and specifications from previous job reviewed for problems?
Specification cover sheet initialed to indicate S&W review?
Design codes specified?
Follow up action required:
Bidder's List Approval:
Demonstrated competence on previous work?
Q/A procedcres reviewed by the A-E?
Firancial report reviewed, if required?
l Purchase Review or Approval:
Have all exceptions to specification been noted and justified by the A-E7 Has memo request for deviation from low bid policy been included, if required?
Has action record for specificatior. approval been reviewed?
I I
Have comercial terms and economic evaluation been reviewed?
Follow up action required? If yes, list how implemented below.
References Used:
Telephone conversations with b(DX k b S fTb$ k' O bbY SCC 5 b1 Y[
See minutes of meeting of C iM1fff'd f T.
Design calculations checked and can be found (where)
SAR Section Study of system design Other
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Verified By