ML20249C813
| ML20249C813 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 07/21/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20249C787 | List: |
| References | |
| NUDOCS 9807010231 | |
| Download: ML20249C813 (27) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION n
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WASHINGTON, D. C. 20556 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR' REGULATION
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SUPPORTING AMENDMENT NO. 20 TO FACILITY OPERATING LICENSE NO. NPF-38 LOUISIANA POWER AND LIGHT COMPANY j
WATERFORD STEAM ELECTRIC STATION, UNIT 3 l
DOCKET NO. 50-382 m
- 1. 0 INTRODUCTION By application dated January 13, 1987, Louisiana Power and Light Company (LP&L or the licensee) requested changes to the Technical Specifications (Appendix A to Facility Operating License No. NPF-38) for Waterford Steam Electric Station, Unit 3 (WSES-3).
The proposed changes would add operability and surveillance requirements for the Broad Range Toxic Gas Detection System (BRTGDS).
2.0 DISCUSSION The proposed changes would add Limiting Condition for Operation 3.3.3.7.3
" Broad Range Gas Detection".and the associated Surveillance Require-i ment 4.3.3.7.3, as well as supporting Bases to the technical specifi-cations.
The installation of a BRTGDS and imposition of the associated technical specifications satisfy Condition 2.C.4, " Broad Range Toxic Gas Detectors,"~of Facility Operating License No. NPF-38 and Supplement No. b to the Safety Evaluation Report (NUREG-0787).
Waterford 3 was allowed to operate during the first cycle without a BRTGD' system due to near-term compensatory measures i.e., periodic surveys of toxic gas inventories, a hot-line communication with the St. Charles Parish Emergency Operations Center (which results in rapid notification in the event of a major chemical release accident in the.
vicinity of the site), a control room operator and plant personnel training program, and procedures with respect to response to toxic gases.
In order to protect the control room for the WSES-3 facility from the effects of potential accidental releases of toxic gases in l
the area of surrounding the site, LP&L has installed duplicate chlorine 1
and ammonia detectors on the air intake of the control room.
These detectors alarm and isolate the control room in the event of detection of air concentration of either of these toxic gases in excess of a preset' limit to protect control room personnel.
Although these 9907010231 990629 PDR :ADOCK 05000302^
P PDR-
, m measures were considered adequate for short-term operation, an additional level of protection will be provided by the BRTGDS for operation over the expected plant lifetime.
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The proposed BRTGDS includes two redundant photofonization detectors.
These detectors monitor the atmosphere in the reactor auxiliary building outside air intake duct.
Whenever the concentration of the detectable gases exceeds a preset limit, these detectors will each induce an electric current in the associated circuit through photoionization, thus generating a signal.
This signal automatically switches the control room air conditioning system to the isolation mode of opera-
. tion.
3.0 EVALUATION i
The staff has evaluated the control room chemical detection systems
~to be utilized by LP&L at the WSES-3 facility.
This detection system includes two redundant chlorine and ammonia detectors which alarm and isolate the control room in the event of detection of either of these airborne pollutants in high~enough concentrations to impact the con-
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trol room personnel.
In addition, the licensee will be notified by the St. Charles Parish, probably within five minutes. in the event of an accident which would release toxic chemicals to the air.
The l
licensee has now completed installation and testing of 2 redundant BRTGD systems.
LP&L has completed a 6-month testing program for the newly-installed BRTGDS and has establihsed a setpoint for alarm and isolation which.provides adequate protection to control room personnel l
q while minimizing the number of spurious alarms.
The combination of detection systems and emergency notification, coupled with procedures and training for toxic gas releases should provide protection of the control room such that potential hazards due to accidental toxic gas releases in the area will be minimized.
Based upon the above evaluation, the staff concludes that the WSES-3
. control room habitability system, which includes the newly-installed l
BRTGDS, meets General Design Criteria 19 with respect to toxic gas i
protection and that the addition of operability and surveillance requirements for the BRTGDS to the Technical Specifications is acceptable.
4.0- CONTACT WITH STATE OFFICIAL The NRC staff has advised the Administrator, Nuclear Energy Division, Office of Environmental Affairs, State of Louisiana of the proposed determination of no significant hazards consideration.
No comments were received.
- 5. 0 ENVIRONMENTAL CONSIDERATION
~The amendment relates to changes in installation or use of a facility \\
component located within the restricted area.
The staff has determined I
' 1 that the amendment involves no significant increase in the amounts and no significant change in the types of'any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in i
Pursuant to 10 CFR 51.22(b), no environmental l
impact statement or environmental assessment need be prepared in
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connection with the issuance of this amendment.
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6.0 CONCLUSION
i Based upon its evaluation of the proposed changes to the Waterford 3 Technical Specifications, the staff has concluded that:
there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and such activities will be conducted in compliance with the Commission's regulations and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
The staff, therefore, concludes that the proposed changes are acceptable, and are hereby incorporated into the Waterford 3 Technical Specifications.
Dated: July 21,1987 Principal Contributor:
I. Spickler l
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f NPF-38-205 REFERENCE 7 LDCR # 98-0054 CHANGE To FSAR SECTIONS 6.4.4.2 AND 2.2A.1.3 l
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PORC REVIEW AND APPROVAL SHEET REVIEW OF: LDCR # 98-0054 The PORC has reviewed this item and determined that a Safety / Commitment Review was performed (if applicable), that a Safety Evaluation was performed (if applicable), that an unreviewed safety question does not exist, and that nuclear safety is/was not adversely affected, and that a Technical Specification Change is or is not required.
RECOMMENDED FOR APPROVAL PORC MEMBER MEMBER SIGNATURE YES NO Maintenance s
.,e Oparations
/
/
Radiation Protection /
/
Quality Plant Engineering M
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Design Engineering VM V
Other Other k
Meeting No.98-011 ;
Item No.
lil Date:
3/4/98 This item is recommended for approval?
BYES O NO This item requires SRC/NRC review prior to implementation?
O YES ENO If yes, ensure documentation supporting review is attached.
1 10CFR50.59 EVALUATION ATTACHED [X]
Credit taken for existing 10CFR50.59 Screening or Evaluation [ ]
RECOMMENDED SIGNATURE FOR APPROVAL YES NO DATE PORC Chairman I
3/9'h/
Comments:
Approved by T
M Date t N General 19la' nager PTant Operations
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UNT-001-004 Revision 15.1 (1 of 1)
10CFR50.59 SAFETY EVALUATION FORM PAGE l
OF 1
Signatures Preparer:
J.S. Reese
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3 -3 'T6 Name (Print) giat ate Reviewer:
P.P. Ola r
r 3-J-ff Name (Print)
Signature /Date Supervisor:
R.T. Thweatt I2IA T/3/78 Name (Print)
Signature /Date
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PART A EXECUTIVE
SUMMARY
SAFETY EVALUATION NUMBER:
DOCUMENT EVALUATED:
CALCULATION EC-M96-002 REVislON 2 & LDCR# 98-0054 Proceduree: OP-100-014 Rev. 8 Chg.1, Technical Specification Compliance; 901-520 Rev. 5 Chg.1, Toxic Chemical Release; 901-622 Rev.1 Chg.1 Seismic Event; OP-003-014 Rev. 6 Chg.1, Control Room HVAC Operating Procedure 1
BRIEF DESCRIPTION OF CHANGE, TEST OR EXPERIMENT.
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The purpose of LDCR # 98-0054 is to revise SAR Sections 6.4.4.2 paragraph E, and 2.2A.1.3 paragraph B. These changes will add a description. to the SAR of administrative controls in place that will ensure the Control Room Envelope CO2 l
concentration does not exceed 1.0%.
In addition administrative controls will be added to the above procedures to monitor CO levels when in isolated mode during 2
normal operations REASON FOR CHANGE, TEST OR EXPERIMENT:
Current procedural limitations require limiting access to the Control Room Envelope to 16 people any time the Control Room is in isolate mode. This limitation may require manning the backup TSC as opposed to the TSC, if E-plan is required to be implemented. These limitations are burdensome on Control Room staff and the plant.
Calculation EC-M96-002 Revision 2 was prepared to determine various CO2 concentration alerts limits for the Control Room Envelope that if adhered to would eliminate the need to limit Control Room access during normal operations. There would only be a need to limit access to the Control Room if CO concentrations are at 2
the alert limit and a toxic chemical event is in progress.
SAFETY EVALUATION
SUMMARY
AND CONCLUSIONS:
This screening and 10CFR50.59 Safety Evaluation confirm that the proposed }
changes to the above procedures and SAR Section 6.4.4.2 and 2.2A.1.3 will not reduce the margin of safety as defined in the SAR or Technical Specification bases, W2.302, Rev. 3 Attachment IV Page 1 of 4
1 i
10CFR50.59 SAFETY EVALUATION FORM PAGE 1 OF 1
nor result in an unreviewed safety question. LDCR # 98-0054 only revises SAR section 6.4.4.2 and 2.2A.1.3 to described administrative controls to limit CO2 concentrations in the Control Room Envelope, when the Control Room is in isolate mode during normal operations. Calculation EC-M96-002 Revision 2 provides a basis for these administrative controls and implementing this change will only bring the SAR into agreement with the conclusions of EC-M96-002 Revision 2.
LICENSING BASIS AND OTHER DOCUMENTS REVIEWED:
4 SAR Section 6.4.4.2; Toxic Gas Protection SAR Section 9.4.1; Control Room Air Conditioning System SAR Section Appendix 2.2A, Evaluation Of Actual Hazardous Chemical Releases Postulated To Occur Near Waterfordlli Site Calculation EC-M96-002 Rev. 2; Carbon Dioxide Generation in Control Room Calculation NOSGL-LPL-90-01; " Control Room Habitability" Regulatory Guide 1.78; Assumptions For Evaluating The Habitability Of Control Room During A Hazardous Chemical Release Regulatory Guide 1.95; Protection Of Control Room Operators Against An Accidental Chlorine Release Standard Review Plan; Section 6.4 Control Room Habitability Systems W3-DBD-038; Safety Related HVAC Control Room Technical Specification 3/4.7.6 SAR Section Appendix 2.2A, Evaluation Of Actual Hazardous Chemical Releases l
Postulated To Occur Near Waterfordill Site l
OP-100-014; Technical Specification Compliance OP-003-014; Control Room Heating And Ventilation Operating Procedure OP-901-520; Toxic Chemical Release OP-901-522; Seismic Event UFSAR CHANGE REQUIRED?
lXlYES l
lNO RADIOACTIVE WASTE SYSTEMS ADDITIONAL SAFETY l
lYES lX l NO EVALUATION ATTACHED?
ENVIRONMENTAL IMPACT EVALUATION ATTACHED?
U YES (Xl NO
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W2.302, Rev. 3 Attachment IV Page 1 of 4 L
10CFR50.59 SAFETY EVALUATION FORM PAGE
'5 OF
'~l PARTB SAFETY EVALUATION QUESTIONS i
81)
Does the proposed change or activity increase the probability.of
[ Yes occurrence of an accident previously evaluated in the SAR7 L
No A.
List accidents in the SAR that may be caus*d by or a#ected by the proposed change or activity orjustify that there is no effect.
B.
For each accident, discuss the effect of the proposed change or activity on the l
likelihood of the accident occurring.
BASIS:
l A. B No accidents in the SAR will be initiated by or have an increase probability of j
occurrence if LDCR# 98-0054 is implemented. The changes being made to SAR section 6.4.4.2 and 2.2A.1.3 will only add a description of the administrative controls to limit CO concentrations in the Control Room 2
Envelope, when the Control Room is in isolate mode during normal operations.
SAR section 6.4.4.2 describes the capacity of the control room with respect to CO generation as having adequate volume to contain 16 people for 6 days 2
without exceeding 1% CO concentrations. During normal operations, Control l
2 room access is limited to 16 people whenever the Control Room HVAC system is in isolate mode due to equiment failure or similar reasons. Revision 2 of Calculation EC-M96-002 will provide a basis for administrative controls to l
monitor CO levels in the Control Room when in the Control Room HVAC 2
l system is in' isolate mode during normal operations. When the CO level 2
reaches an. alert limit established in EC-M96-002, controls would be implemented to ensure CO levels are acceptable during a Toxic Chemical 2
Event. The alert limit and administrative controls are implemented by the procedures OP-100-014,901-520,901-522, and OP-003-014.
l B2)
Does the proposed change or activity increase the consequences of an Yes accident previously evaluated in the SAR?
L No A.
List accidents in the SAR that may have radiological release consequences altered by the proposed change or activity, or justify that no accidents are affected.
B For each accident, discuss the effect of the proposed change or activity on the radiological release consequences, include the effect of the proposed change or l-activity on mitigating system performance and analysis assumptions credited in the l
accident analysis.
l C.
If applicable, provide the results of a new analysis that accounts for the proposed j
change or activity.
BASIS:
A, B, C No accidents in the SAR will have increased radiological consequences as a result of implementing LDCR# 98-0054. This change will only alter information in the SAR to describe administrative controls in place that allow monitoring CO concentrations vs. the need to limit access to the Control Room when in 2
isolate mode. The proposed change will not affect the ability of the Control l
Room HVAC system or envelope in performing its safety function.
W2.302, Rev. 3 Attachment IV Page 2 of 4
l 10CFR50.59 SAFETY EVALUATION FORM PAGE 4
OF q
B3)
Does the proposed change or activity increase the probability of Yes occurrence of a malfunction of equipment important to safety previously JL No evaluated in the SAR?
A.
Identify the equipment important to safety that could be affected by the proposed change or activity, or justify why no equipment important to safety is affected.
B.
Discuss the effect the proposed change or activity may have on equipment important to safety.
Include a determination of whether the likelihood of malfunction will increase.
BASIS:
A, B The Control Room HVAC system nor any other plant equipment is being modified by this change. This change only revises SAR section 6.4.4.2 and 2.2A.1.3 to reflect conclusions of design basis calculation EC-M96-002 Revision 2.
Therefore, approval of LDCR # 98-0054 will not increase the probability of occurrence of a malfunction of equipment important to safety.
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I W2.302, Rev. 3 Attachment IV Page 2 of 4
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10CFR50.59 SAFETY EVALUATION FORM PAGE 5 OF l
B4)
Does the proposed change or activity increase the consequences of a Yes malfunction of equipment important to safety previously evaluated in the SAR.
L No A.
List the accidents for which the equipment important to safety in 3A above is required to perform a safety function.
B.
For each accident, discuss how the consequences may be different if the equipment in l
3A above were to malfunction.
BASIS:
A, B.
The proposed changes are documentation only, no greater reliance is placed j
l on any equipment or system important to safety. Currently if the Control Room is in isolate mode, (BRGM's are out of service), Control Room access is limited f
to 16 people. This places a greater burden on the Control Room staff and l
limits available resources should there be a need to implement the E-Plan.
l Calculation EC-M96-002 Rev. 2 provides a basis to monitor CO 2 concentrations and not limit access to the Control Room.
Changes to 4
procedures OP-100-014, 901-520, 901-522, and OP-003-014 provide a l
method to implement the administrative controls necessary. These actions improve the ability of the Control Room staff to function during normal operations, and when the E-Plan is implemented Therefore, there is no
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increase in the consequences of a malfunction of equipment important to safety.
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B5)
Does the proposed change or activity create the possibility of an accident of a Yes different type than previously evaluated in the SAR?
L No A.
Discuss new system interactions or connections that did not previously exist.
B.
Discuss how these new system interactions or connections could or could not create a j
new accident.
BASIS:
A, B The proposed changes are to SAR sections 6.4.4.2 and 2.2A.1.3 only. No new I
system interactions or modes of operation will be created. LDCR# 98-0054 will not create the possibility of any new accidents not previously evaluated in the SAR.
B6)
Does the proposed change or activity create the possibility of a malfunction Yes of equipment important to safety of a different type than any previously L
No evaluated in the SAR?
A.
Discuss new system interactions or connections that did not previously exist.
BASIS:
No new methods of failure are created because the proposed changes do not affect ariy plant equipment. No different type of malfunction of equipment important to safety will be created.
i W2.302, Rev. 3 Attachment IV Page 3 of 4
10CFR50.59 SAFETY EVALUATION FORM PAGE
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OF 1
B7)
Does the proposed change or activity reduce the margin of safety as Yes defined in the bases for any technical specification or the appropriate X_ No safety analysis?
A.
If the change is to a protective boundary, discuss how the boundary is affected.
B.
Identify the margins of safety (related to boundary performance) that may be affected by the proposed change or activity.
C.
Discuss how the accident response, as affected by the proposed change or activity, relates to the appropriate acceptance limits.
I D.
If applicable, provide the results of an analysis that accounts for the proposed change or activity and shows the impact on margin of safety.
BASIS:
LDCR# 98-0054 will not affect the Technical Specification bases nor alter any protective boundary.
It only revises SAR section 6.4.4.2 and 2.2A.1.3 to described administrative controls to limit CO concentrations in the Control l
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Room Envelope, when the Control Room is in isolate mode during normal operations. Technical Specification change request NPF-38-205 has been PORC approved to revise Technical Specifications 3.3.3.7.1 & 3.3.3.7.3. The revision will allow ventilating the Control Room every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> duration, if a toxic chemical event is not in progress. Approving LDRC# 98-0054 does not affect this change request.
LDCR# 98-0054 reflects conclusions of calculation EC-M96-002 Revision 2, and will not reduce any margin of safety. The following procedure changes: OP-100-014 Rev. 8 Chg.
1, Technical Specification Compliance; 901-520 Rev. 5 Chg.1, Toxic Chemical Release; 901-522 Rev.1 Chg.1 Seismic Event; OP-003-014 Rev. 6 Chg.1, Control Room HVAC Operating Procedure, will only provide a method to implement the above changes improving the ability of the Control Room Staff to function during normal operations and a Toxic Chemical Event.
b W2.302, Rev, 3 Attachment IV Page 4 of 4
10CFR50.59 SAFETY EVALUATION FORM PAGE 1
OF 1
PART C 4
RADIOACTIVE WASTE SYSTEMS MODIFICATION & UNPLANNED RELEASE APPLICABILITY i
REVIEW lF THE FOLLOWING QUESTION IS ANSWERED "YES," THEN A RADIOACTIVE WASTE SYSTEMS ADDITIONAL SAFETY EVALUATION (ATTACHMENT VI) MUST BE COMPLETED AND ATTACHED TO THIS FORM.
ATTACHMENT Vill MAY BE USED IN ANSWERING THIS QUESTION.
Does the proposed change or activity represent:
C1) A change to a radioactive waste system or a potential to cause an Yes uncontrolled, unplanned, or unmonitored release?
IL No l
l PART D ENVIRONMENTAL EVALUATION APPLICABILITY REVIEW IF THE FOLLOWING QUESTION IS ANSWERED "YES," THEN AN ENVIRONMENTAL IMPACT EVALUATION i
l (ATTACHMENT Vil) MUST BE COMPLETED AND ATTACHED TO THIS FORM. ATTACHMENT lX MAY BE USED IN ANSWERING THIS QUESTION.
Does the proposed change or activity represent:
l D1) A change to the Environmental Protection Plan, or a change that may affect 6
Yes the environment?
lL No l
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W2.302, Rev. 3 Attachment IV Page 4 of 4
l LICENSING DOCUMENT CHANGE REQUEST FORM PAGE 1 OF 3 ICENSING DOCUMENT CHANGE REQUEST (LDCR) NUMBER: 98-0054 (To Be Assigneo By Licensing)
DESCRIPTION OF PROPOSED CHANGE:
Revise the below SAR sections to Indicato new administrative controls in place to ensure a CO concentration limit of 1.0% is not exceeded in the Control Room 2
Envelope.
UFSAR SECTIONS, TABLES, OR FIGURES REQUIRING CHANGES:
l 2.2A.1.3 Control Room Habitability 6.4.4.2 Toxic Gas Protection l
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ATTACH ALL UFSAR PAGES AFFECTED BY THE PROPOSED CHANGE. MARK UP THE UFSAR PAGES SO THAT THE PROPOSED CHANGE CAN BE CLEARLY UNDERSTOOD. IF THE PROPOSED CHANGE REQUIRES PORC REVIEW, THEN FORWARD A COPY OF THE PRE-SCREENING OR SAFETY EVALUATION WITH AN LDCR FORM TO LICENSING AFTER PORC REVIFW. IT IS THE RESPONSIBILITY OF THE PREPARER TO ENSURE THAT LICENSING RECEIVES A COPY OF THE LDCR FORM.
Preparer.
J.S. Reese r 2-/7-fg Name (Print)
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Signature /Date W2.302, Rev. 3 Attachment X Page 1 of 1
WSES FSAR UN!T-3 L D CA
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PAGE % ofr 3 of self contained breathing air apparatus. if these are necessary. Since the Livingston derailment lasted several days, it is appropriate to ask whether the Control Room would remain habitable over the duration of the accident.
Should such an accident occur, toxic chemicals and products of cost)ustion may be present at the air intake of the Control Room for several days, necessitating prolonged isolation of the Control Room.
Although a large amount of highly toxic materials was released following the Livingston derailment, the results of this analysts have shown that if a similar accident were to occur in the vicinity of the Waterford 3 site, the chemicals would not have r
1 h21t2111ty. As i 1 in S t1
- 6.. Ac Canbl com ma is +ch h.y re mat n u,o M un ' h wm i% an resh &
1 61; sm to
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f rec ton t of r i t exceeded hoguiMC gy 1,c, c,
= ut r..; -f 'u :t I; Mt -N. ' ~;e,en;on n" 5.:td rti s
gure
. tne same Ts'truei>ThturteMi!TtTons. even~negiecting the fact that the land
~
gg slopes away from the plant towards the railroad.
It should be noted that the two Control Room Emergency Ventilation intakes are on opposite sides of the RA8.
The operator, therefore, has the capability to selectively provide make up air based on accept $le concentrations.
2.2A.1.4 Fires and Explosions The fires that can result from the spillage of the hazardous materials from the derailed train cars can be caused by a) burning of the material ist the train car, b) burning at the surface of any liquid pool of flansable material formed by leakage from the tank cars, or c) i deflagrations of vapor clouds with the fire eventually retreating to the source of the l
cloud.
In the first case the maximum horizontal extent of the fire cannot be much more th area covered by the derailed train. Thus, on the basis (see Figure 2.2A 3) that the probability of a car exceeding a perpendicular distance from the track from which it
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deriiled is negligible past 500 feet, the farthest fringes of such fires. toward the plant would remain 1.500 feet away from any plant structure important to safety.
At this distance thennal effects are negligible.
In the second case it is necessary to determine what the dimensions of the liquid pool may Such discussions are of course a function of a multiplicity of variables.
be.
However, a statistical sampling of train accidents involving propane spills indicates that pools exceeding lateral dimensions of 200 feet are of negligible probability. although long pools are possible. (See Figure 2.2A 4.) Given the bpography of the Waterford 3 site wherein the ground slopes gently upward from the railroad bed to the plant. it is logical to surmise that only the longest pool dimension will be in a direction away from the plant, and hence thiit the fires from liquid pools would be no closer to the plant than 200 feet from their sources. Hence even 1f a train car travels 500 feet toward the plant then spills its contents the closest resulting fire (if any) to the plant will be approximately 1.300 feet.
at wh1en dtstance thermal effects would be negligible. In either case. however the transmission lines located overhead of the 2.2A.5 i
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WSES-FSAR-UNIT-3 Strip chart recording is provided in the control room. Table 6.4-4 lists examples of g&ses which are detee'able by the Broad Range Gas Detection system, along with the relative sensitivity of the system to each gas and the ionization potential of that gas. A complete list of detectable gases would include most known chemicals.
l A single gas chromatograph is also installed to sample the control room air intake. This gas chromatograph will not provide automatic acbon of control room isolation. It is provided to assist the operator in determining the charactenstics of the gas or gases that actuated the broad range gas detectors Since this gas chivir,sevgriph also operates on the photoionization principle and it is operated at 10.2 electron volts, its programming will respond to only a limited number of distinct gases. A printout o' Me specific gas and its concentration is provided in the control room.
The broad range gas detectors are designed to be very sensitive to numerous gases and are i
calibrated to protect against the most dangerous toxic gas. This causes them to also actuate in response to levels of other gases that are not' toxic. The gas chromatograph is programmed to be responsive to the most common or most likely visible gases however not r+:::rily toxic. This i
will aid the operators in making an assessment of the ability of reopening the control room air intake.
m d).
Industry Hot Line Waterford 3 is a participant in the St. CharteWParish Emergency Preparedness / industrial Hot Line System. This is a dedicated cc'nmunicatiorihetwork between St. Charles Parish Emergency i
Operations Center (EOC) and industries in St. Charios Parish. In the event of an emergency, the affected industry would promptly notify the EOC of the class of emergency, the type of incident and the recommended schons. The EOC will then notify affected neighboring industries, e)
Carbon Dioxide Generation and Oxygen Depidtion e w m
y Carbon dioxide production was calculated to demonstrate the cepectly of the control room in terms of the I
number of people it con accommodate for an extended period of time and not exceed a CO concentndion 2
i of 1 percent when in isolete mode. Resulte show.that the control room con accommodate 16 people for I
greater than 6 days without ventilating with fresh air. A oxygen level of 17 percent would be reached for i
i sixteen people after 19 days. The above results.are based on the assumption that the control room
) envelope will be sc-;"ri soleted During periods of titu the control room is isolated, act'ess does not i
have to be limited if CO levels are monitored and maintained below an administrative limit. When the CO2
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2 level reaches an administrative alert limit, administrative controls would be implemented to ensure CO2 levels remain acceptable durtrag a toxic chemical' event. Due to wind speed, oespersion, etc., calculations l
show the duration the control room would have to remain isolated for a toxic chemical event is no greater
> then 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Therefore, control room staff limits, for a toxic chemical event, are based on a 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> M
f)
Emergency Air Supr.ly System RE% E.
Human detection is relied on to detect some of the other postulated toxic gas accidents identified in Subsection 2.2.3. The analysis, utilizing the guidance of NRC Regulatory Gu',de 1.78, (6/74) shows that with the use of the Emergency Air Supply System the control room will remain habitable.
An Emergency Air Supply System for the Main Control Room (MCR) is provided to ensure a minimum six hour supply of air for control room and security personnel. The system s
3 6.4-9 Revision 9 (12/9',)
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- NPF-38-205 REFERENCE 8 FSAR SECTION 2.2A.1 ANALYSIS OF THE POSSIBLE CONSEQUENCES OF THE LMNGSTON, LOUISIANA DERAILMENT ACCIDENT ON THE WATERFORD 3 PLANT l
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WSES FSAR-UNIT-3 APPEN0!X 2.2A EVALUATION OF ACTUAL HAZARDOUS CHEMICAL RELEASES POSTULATED TO OCCUR NEAR THE WATERFORD 3 SITE 2.2A.1 ANALYSIS OF THE POSSIBLE CONSE0VENCES OF THE LIVINGSTON.
LOUISIANA DERAILMENT ACCIDENT ON THE-Waterford 3 PLANT 2.2A.1.1 Introduction I
At 5:00 AM on September 28th. 1982. 43 cars of a 101 car train derailed in an accident near Livingston, Louisiana. The derailment resulted in a series of fires and explosions which
. lasted several days ind necessitated the evacuation of a three mile radius of the accident area. Though the accident occurred far from the Waterford 3 plant. It is of interest to LP&L to evaluate such an accident as if it had occurred on the Union Pacific Railroad which passes near the Waterford 3 plant.
i The following presents an analysis of the possible plant safety implications of a similar accident occurring at the Waterford 3 site and may be considered a supplement to analyses previously performed and included in Chapter 2 of the Waterford 3 FSAR. In that section, a detailed analysis of over 200 sources of hazardous chemicals is provided. The analyses address the effects of the release of toxic chemicals on Control Room habitability and the effects of near site explosions on plant safety. Though detailed analyses are provided and it has been demonstrated that both engineered safety features and administrative controls are sufficient to ensure plant safety. It has also been acknowledged at the 1982 ACRS meeting that a periodic reassessment of these potential hazards is appropriate. This analysis is provided in accord with that commitment.
The question which is answered in this report is the following:
If a similar derailment accident occurred at the Waterford 3 site, could the toxic chemicals released seriously affect Control Room habitability and could the -
explosions directly affect plant safety?
' The report is divided into four sections. Following this introdt ction, Subsection 2.2A.1.2
{
presents a description of the Livingston accident. Subsection 2.2A.1.3 presents an analysis i
of the possible effects such an accident at the Waterford 3 Site could have on Control Room habitability. The analysis addresses the acute effects of toxic chemicals on the Control
' Room habitability, and the ability of the Control Room to remain habitable over the duration of such an accident. Subsection 2.2A.1.4 presents the possible consequences of the explosions resulting from such an accident on plant safety. The analyses specifically address overpressure, missiles and damage to offsite power supplies.
2.2A.1.2 Accident Summary il'
' The information provided in this section was obtained from 1) newspaper reports 2) telephone conversations with representatives of the National Transportation Safety Board
'(NTSB), the Louisiana Department of Natural Resources, the Louisiana State Police (Hazardous
. Substance Control Unit) and the EPA and 3) reports provided by the NTSB and State of 2.2A-1 l:
I WSES FSAR-UNIT-3 Louisiana. At 5:00 AM on September 28, 1982, 43 railroad cars of a 101 car train derailed near Livingston, Louisiana. On the track, the 43 cars were 2.200 feet long, but following the derailment they covered 725 feet. Of the 43 derailed cars. 27 carried toxic and/or explosive chemicals, The derailment caused a fire and a series of explosions which continued over a 14 day period.
The derailment and subsequent explosions were heard by several emergency response personnel who lived near the accident and responded immediately, All emergency personnel were activated within 15 minutes of the accident. Immediately after the accident, a one mile radius around the derailment site. including Livingston, was evacuated. Shortly thereafter.
a three mile radius was evacuated. A total of 2.800 people were evacuated. The evacuation was performed primarily because of concern over explosion, fire, and toxic chemical I
releases.
Table 2.2A-1 presents the types and quantities of toxic chemicals released during the l
accident. The following presents a brief description of each chemical.
Ethylene Glycol. a liquid at Nor:nal Temperature and Pressure (NTP - 20*C. 760 Torr) boils at 275*F and ignites at 445'F. It is an irritant to the eyes and to the nose if inhaled.
Hydrofluos111cic acid, also known as fluosilicic acid, is produced only in aqueous l
solution. The raterial released in the accident was shipped from a chemical plant in l
Uncle Sam. LA, now Agrico Uncle Sam. That facility ships hydrofluosilicic acid in aqueous concentrations of 233 to 271.(5) Other industry sources confirmed that concentrations of the comercial product never exceed 303. At such concentrations.
l the acid does not present an inhalation hazard.(3) Recommended personal protective I
equipment consists of rubber gloves, safety glasses and protective clothing. No respiratory protection is recomended.
Phosphoric acid, a liquid at NTP, boils at 266*F. It is not flammable. Heated to decomposition. it produces toxic fumes of P0x. Fumes cause burns on the mouth and lips nausea and vomiting, i
Tetraethyl lead, a liquid at NTP, decomposes above 230*F. It explodes in fires, At least one tank car of tetraethyl lead exploded in the Livingston. Louisiana train i
derailment. Vapors cause eye and skin irritation. Inhalation causes nausea.
vomiting and intoxication.
l i
Toluene diisocyanate. a liquid at NTP, boils at 231*F and ignites at 997'F. emitting toxic fumes during cont >ustion. Exposure to vapors causes eye and skin irritation.
Inhalation of vapors causes coughing and gagging.
Perchloroethylene, a liquid at NTP, boils at 250*F. Exposures to concentrations in excess of 200 ppm can cause irritation to the eyes, nose and throat mental confusion. nausea and vomiting. At elevated temperatures, it will decompose into toxic fumes of chlorides.
l-2.2A 2
WSES FSAR UNIT-3 Styrene Monomer, a liquid at NTP boils at 293*F and ignites at 914*F. The vapor is heavier than air and can explode. The vapors can cause eye and skin irritation.
Inhalation can cause dizziness or narcosis.
. Vinyl chloride, a gas at NTP ignites at 882*F. The gas is heavier than air and is highly explosive. One tank car of vinyl chloride in the Livingston. Louisiana train was blown apart by a BLEVE (Boiling Liquid Expanding Vapor Explosion) propelling the ends of. the tank car 500 feet.
Exposure to vinyl chloride vapor can cause eye and skin irritation. Inhalation of vinyl chloride vapor can cause dizziness or. in elevated doses, anaesthesia.
Incomplete combustion of vinyl chloride can result in the production of phosgene, a highly toxic gas.
Rail cars containing metallic sodium which explodes and burns upon contact with water.
l.
sodium hydroxide, a corrosive base, and polyethylene pellets were removed from the wreck.
j.
essentially intact.
Though the accident was extremely severe, and lasted about 14 days, there were no serious injuries among the general public or emergency response personnel, h
l 2.2A.1.3 fontrol Room Habitability In this section, the ' accident is postulated to occur on the Union Pacific Railroad. at its l
nearest point to Waterford 3 724 meters south of the Control Room (see Figure 2.2A 1). Two issues are addressed. The first relates to the short-term peak concentrations of toxic chemicals in the Control Room, and the second relates to the long term nature of the accident and its possible effects on long tem occupancy of the Control Room. Refer to
' Subsection 6.4 for a discussion on Control Room habitability systems.
A.
Short Term Consequences l
The.inpact of the postulated accident on control room habitability was assessed using the methodology described in Subsection 2.2.3.3. The list of hazardous materials was first screened to eliminate those which did not require a detailed analysis.
Following the guidance of Regulatory Guide 1.78. four chemicals-ethylene glycol.
l phosphoric acid, tetraethyllead and toluene diisocyanate -were eliminated because their vapor pressures at 100*F are below 10 torr (un Hg). In fact all four l
pressures are approximately 1 torr or less. Of the remaining chemicals vapors from l
hydrofluosilicic acid do not pose a health hazard, as discussed in Subsection l
2.2A.1.2. Fuel or lubricating oils are also non volatile materials which do not pose i
inhalation hazards when released in an outdoor environment.
The remaining three chemicals spilled in the derailment were evaluated in a manner similar to that described in Subsection 2.2.3.3.4 for stationary sources. The details of-these analyses are presented in Table 2.2A 2. It was conservatively assumed that the total quantity of each chemical was released at the point on the I
Union Pacific tracks nearest to Waterford 3.
The first three coltnrs in the Table
- s after the chemical name list the IDLH concentration. the odor threshold and the 1
l ionization potential of each chemical. These properties are discussed in 2.2A 3 I
WSES FSAR UNIT-3 Subsection 2.2.3.3.4. The next-to last column lists the maximum concentration in the control room at the time the operators are assumed to have donned their breathing apparatus. The final column lists the ratio of this concentration to the IDLH-concentration for the given chemical. The stn of these ratios is a measure of the combined toxicity of the three gases. As is shown in the Table. the sum of the concentration ratios'is equal to 0.27. showing that the combined effect of the three j
gases would be well within the limit set by the IDLH values.
- The analysis is conservative in the following respects:
a.
The maximum concentrations for the three chemicals are found to occur under three different sets of meteorological conditions: therefore, all three concentrations could not occur simultaneously, b.
All the releases were assumed to occur at the same point. Actually, as stated in Subsection 2.2A.1.2. the 43 cars involved in the derailment were spread over a distance of 725 feet. Therefore, portions of the release would i
have to occur at a greater distance than the postulated 724 meters. More j
importantly, each car containing one of the chemicals in question would constitute a discrete source -only one of those sources could be directly upwind of the control room air 4atake.
C.
The analysis calculates the concentrations of the three chemicals as if each occurred separately, when in fact the three plumes would dilute one another.
Before leaving this section several additional factors need to be emphasized:
1)
The fires and heat will cause decomposition of some of the toxic chemicals.
I 2)
The heat of the fires will cause large updraft of many toxic chemicals which might otherwise be available near ground level, resulting in greater dispersion.
3).
Tne explosions will give imediate notification to Waterford 3.
Either they or one of the chemical facilities nearby will contact emergency response authorities on the " hot line". In the case of the Livingston.
Louisiana derailment, emergency response personnel were on scene within 15 minutes.
4)
The derailment will occur downhill of Waterford 3 (see Figure 2.A 2). Thus, j
under cala meteorological conditions, when atmospheric dispersion is i
reduced, chemicals which are significantly heavier than air would be j
transported away from the Waterford 3 site.
l l
l j-8.
Long-Term Effects l
l
' The accidents analyzed in Section 2.2 of the FSAR are extremely intense accidents which last from minutes to hours. For chemical releases which persist for a long period of time, protection is provided by continued Control Room isolation and use 2.2A 4
)
l
WSES FSAR UNIT-3 of self-contained breathing air apparatus. If these are necessary. Since the l
Livingston derailment lasted several days it is appropriate to ask whether the Control Room would remain habitable over the duration of the accident.
Should such an accident occur, toxic chemicals and prcducts of combustion may be present at the air intake of the Control Room for several days, necessitating prolonged isolation of the Control Room. Although a large amount of highly toxic materials was released following the Livingston derailment, the results of this analysis have shown that if a similar accident were to occur in the vicinity of the Waterford 3 site, the chemicals would not have an adverse impact on Control Room habitability. As indicated in Subsection 6.4. assuming seven occupants, the Control Room may be. isolated for 130 hours0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br /> (5.4 days) before CO.) buildup reached one 2
percent and requires ventilation. A review of the meteorological record (see Table 2.2A 3) reveals that SW to SE (appropriate range of direction from segment of rail line) wind persistence has not exceeded 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />. Accordingly, the Control Room may remain isolated until the wind shifts and fresh air is taken in. As seen on Figure 2.2A 2, the same is true of calm conditions, even neglecting the fact that the land slopes away from the plant towards the railroad. It should be noted that the two Control Room Emergency Ventilation intakes are on opposite sides of the RAB.
The operator, therefore has the capability to selectively provide make up air based on acceptable concentrations.
2.2A.1.4 Fires and Explosions The fires that can result from the spillage of the hazardous materials from the derailed
. train cars can be caused by a) burning of the material in the train car, b) burning at the i
surface of any liquid pool of flammable material formed by leakage from the ' tank cars, or c) deflagrations of vapor clouds with the fire eventually retreating to the source of the i
- cloud, in the first case the maxin.um horizontal extent of the fire cannot be much more than the area covered by the derailed train, Thus, on the basis (see Figure 2.2A 3) that the probability of a car exceeding a perpendicular distance from the track from which it derailed is negligible past 500 feet, the farthest fringes of such fires toward the plant would remain 1.500 feet away from any plant structure important to safety.
At this distance thermal effects are negligible.
In the second case it is necessary to determine what the dimensions of the liquid pool may be.
Such discussions are of course a function of a multiplicity of variables. However, a statistical sampling of train accidents involving propane spills indicates that pools exceeding lateral dimensions of 200 feet are of negligible probability, although long pools are possible. (See Figure 2.2A 4.) Given the topography of the Waterford 3 site, wherein the ground slopes gently upward from the railroad bed to the plant. it is logical to surmise that only the longest pool dimension will be in a direction away from the plant and hence
'that the fires from liquid pools would be no closer to the plant than 200 feet from their sources. Hence even if a train car travels 500 feet toward the plant then spills its contents, the closest resulting fire (if any) to the plant will be approximately 1.300 feet, at which distance thermal effects would be negligible. In either case, however, the transmission lines located overhead of the
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i t
2.2A-5 l
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WSES FSAR UNIT 3 derailed train.would have to be assumed as lost. The height of the flame from pool fires is known to exceed tens and even 100 feet (as for instance Figure 2.2A 5 shows for LNG). Since the length of the derailment area can be about 1.000 feet. and pools can be of similar or longer lengths, either fires from the train cars or from ensuing pools can simultaneously damage the overhead lines, although the probability of that occurrence is perceived to be low, It should also be noted that there is significant separation between the two overhead transmission lines as they cross the railroad.
l Finally, rapid fires, or deflagrations, are examined. Deflagrations of vapor clouds result in overpressure which are lower than those resulting from detonations of the same clouds.
However, the thermal effects of deflagration can be more pronounced than those of detonation since the event lasts a considerably longer time, i
The kinds of vapor clouds that can be formed from derailments result from either evaporation of liquid pools and subsequent atmospheric dispersions toward the plant or gravity slumping about the source. For the particular products carried by the train derailed in Livingston, the major hazardous component vinyl chloride is a gas heavier than air which will slump by gravity about the source unless wind speeds are very significant, since slumping velocities i
l will be of the order of 35 fps initially and still be about 13 fps when the vapor cloud is I
about two feet thick.
Again because of, the geographic contour such a cloud would slump away from the plant. At a thickness of two feet the vapor cloud could travel about 1.000 feet from the railroad bed (this distance corresponds to the radius of a pancake cloud of two foot average thickness and also the distance from the railroad track at which the ground rises by more than two feet). Thus, it is reasonable to expect that the extent of the vapor cloud would not extend more than 1.000 feet toward the plant. In actuality it would probably be less. since slumping will be away from the plant.
Vinyl Chloride cannot explode until it entrains sufficient air to drop its. volume concentration below 22 percent. Since the initial process of slumping does not entrain much air, the mixing must occur farther way from the plant than the initial extent of the cloud.
Hence, one can model the deflagration of such vapor cloud as one of a cloud that originally would be no closer than 1.300 feet to the plant structures. The expansion of the cloud as it burns produces a two fold increase in dimension, and hence at the end of the deflagration l
- the flame front may be just 300 to 400 feet away from the plant safety structures. Because of the short duration of the deflagration, again this would not be considered to present a thermal problem.
l The deflagration would also create an overpressure, but of a value lower than that caused by the detonation of the vapor cloud. 'If the cloud were to detonate it would have the l
equivalent yield of a 150 ton TNT detonation (it is not known if vinyl chloride can detonate i
in open air), and a 3 ps1 overpressure would be generated if it is assumed that the center of the detonation is conservatively 1.300 feet away from the plant.
Because of the lower quantities of the other hazardous materials, and their comparable or lower explosive yield. involved in the Livingston derailment. their hazards to the plant.
even by atmospheric dispersion toward the plant are expected to be less than those caused by vinyl chloride.
l 2.2A 6 l-
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1 WSES FSAR UNIT-3 Finally, the question of missiles generated by either the accident itself or an explosion is addressed. Figure 2.2A 6 illustrates that statistically missiles travel as far as the distance from the railroad to the plant. Similarly Figure 2.2A-7 shows that debris and missiles from a'150 ton of TNT equivalent detonation are capable of reaching distances in excess of 2.500 feet.
It is therefore possible for missiles generated from the accident to reach the plant. Since neither the velocities nor the missile sizes are known it cannot be said with certainty i
whether they can present a hazard. An approximate assessment can be made however, by
)
considering the kind of missiles that can reach the plant from a 150 ton detonation (larger l
missiles fall at shorter distances) at 1.300 feet.
I To ascertain the probability of a missile from the 150 ton TNT explosion hitting a critical 1
structure, it is assumed that the total weight of missiles is proportional to the volume of f
the crater which would be created by the detonation. had it been a TNT detonation near the I
surface. The crater in turn is proportional to the detonation yield. Roughly the volume of I
the crater is estimated by the scaling law and the knowleogo that a one kiloton surface detonation in dry soil results in a crater diameter of 180 feet ed depth of 35 feet.
1 Assuming none of the mass falls back within the crater. the areal censity 1.300 feet away l
from the center of the assumed detonation is 8.4 x 10-3 lb/ft.2 The area of the critical l
structure being of the order of 105 ft2. the total weight of missiles hitting these areas would only be 421 lbs. Assuming that all of this mass is concentrated in one missile. and that missile travels at the maximum air particle velocity of 140 ft per sec, the impact energy of this missile is below the energy required for penetration of the structures (see response to Question 311.2). In sumary, explosively driven missiles do not pose a significant risk to the plant.
2.2A.2 ANALYSIS OF THE POTENTIAL CONSE0VENCES OF THE DECEMBER 11. 1982 EXPLOSION AT THE UNION CARBIDE PLANT ON WSES 3 2.2A.2.1 Introduction At 12:45 AM on December 11.1982 (as recorded by the Waterford 3 Control Room). an explosion l
occurred in a tank at Union Carbide. This tank was about one-half empty and contained 20.000 gallons (approximately 225.000 lbs) of acrolein. The tank is one in a group of five located approximately two miles from Waterford 3.
Radio reports indicate that windows were shattered two miles away across the river. Effects of the explosion felt at Waterford 3 included a non essential unlatched door near the Control Room blown open, and electric power t
transients including flickering lights and spurious alarms. No loss of offsite power occurred at Waterford 3. and all operating LP&L fossil stations remained on line. The explosion threw debris from the tank up to one half mile away displacing the destroyed tank nine feet. and destroyed much of the piping connecting the five tanks with the equipment used to keep the tank's contents at a low pressure.
Louisiana Power & Light Company has analyzed the effects of this incident. In these analyses. the habitability of the Control Room and the plant overpressure from the explosion i
have been studied. The results of these analyses show that the accident consequences are well within the design basis events for Waterford 3.
The analyses are described below.
e 7.2A.7 4.
I
WSES FSAR UNIT-3 2.2A.2.2 Acrolein Acrolein is primarily used as an intermediate.in the production of glycerine and in the production of methionine analogs '(poultry feed protein. supplements). It is ali.o used in chemical synthesis, as a liquid fuel, antimicrobial a control. and as a slimicide in paper manufacture.(1) gent in algae and aquatic weed The Federal standard for occupational exposure to airborne concentration of acrolein is 0.1 ppe. This is the Time Weighted Average (TWA) value as of 1980. The Short Term Exposure Level (STEL) value is 0.3 ppm. Immediately Dangerous to Life or Health (IDLH) value is 5.0 ppm as opposed to anhydrous ammonia (500 ppm) or chlorine (25 ppm).
j l
In the liquid or pungent vapor form. acrolein produces intense irritation of the eye and
' mucous membranes of the respiratory tract. Skin bums a:'d dermatitis may result.from
. prolonged or repeated exposure. Because of acrolein's pungent, offensive odor and the intense irritation 'of the conjunctiva and upper respiratory tract.' severe toxic effects from acute exposure are rare as workers will.not tolerate the vapor even in minimal concentration.
The properties of acrolein are such that when cooling is lost to the tank.'.an explosive reaction.can set in when the temperature of the substance exceeds 453T. The most-conservative calculations indicate that the explosive capability of acrolein coc~d be as high:as six times that of TNT: Indicating that the five tanks of acrolein are equivalent to
, approximately 7.000 tons (14 million pounds) of TNT. The atmospheric boiling point of I
acrolein is 127T (52*C): therefore, the substance will tend to puddle on the ground and f
evaporate, but not form an explosive cloud. It is estimated that 10.000 to 15.000 lbs of acrolein formed the initial explosion: the approximately 210.000 lbs remaining in the tank burned off in about 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />.
2.2A.2.3 Accident Scenario Acrolein is a 110uid St atmospheric pressure (as opposed to anhydrous amonia or chlorine.
l which are gases): the chance that large quantities of acrolein will become airborne is small. When heated. acrolein emits highly toxic vapors. In a fire. the vapors burn and are prevented from becoming airborne. Thus, with respect to adverse impact on Control Room l-habitability, a more severe. 'and less probable scenario would involve ~ the evaporation of i
acrolein without ignition. The letter scenario is assumed for this evaluation.
L.
2.2A.2.3.1 Control Room Habitability Evaluation'Hethodoloay -
The maximum credible accident invol'ving the release of acrolein at the Union Carbide Industrial Chemicals facility in Taft. LA is the process failure involving one tank. Since
- dikes would coly contain 25% of such a release, for purposes of a conservative analysis the
< source is considered undiked. The impact of.Such an accident was analysed as part of the i-evaluation of all toxic chemical sources in the Waterford 3 vicinity. described in Subsection 2.2.3.3. The specific assumptions employed in this analysis are sumarized in
. Table 2.2A-4.
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2.2A.8 b
l WSES FSAR UNIT-3 One tank contains a maximum of 425.000 pounds of acrolein at ambient temperature and pressure, as reported by Union Carbide during the 1988 survey of toxic chemicals. These tanks are located in Area 34 of the Union Carbide Industrial Chemicals plant. Measurements made using the plant's plot plan and the U.S. Geological Survey map of the area (the Hahnville. LA 7.5 minute quadrangle, photo revised in 1979) show'the nearest point in this
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area to be 1.75 miles from the Waterford 3 control room air intake.
Control Room Parameters The normal control room air exchange rate is 0.6 volume per hour, based on a net free volume of the control room envelope of 220.000 cu. ft. and a normal outside air makeup rate of 2200 cfm. as listed in Table 6.4 2. The height of the outside air intake is listed as 73* above HSL, while the site plan shows the ground elevation to be between 12' and 13' above MSL. for a net height above ground of approximately 60*.
The air exchange rate after control room isolation is assumed to be 0.06 volume per hour. in accordance with Regulatory Guide 1.95.
Rev.,1. Regulatory Position 5.
Characteristics of Broad Range Gas Detector System The photoionization detectors, which are part of the Broad Range Gas Detector System (BRGDS), are adjusted to alarm and isolate the control room when the acrolein vapors reach a constant concentration of 3 ppm. The actual response of the detector, which depends on the time-varying concentration of the vapor, was modeled as follows.
A commonly-used equation for the response of an electronic instrument. such as the BRG05, to l
a step function increase of the quantity being measured. such as concentration. is:
T ln(1 - y/x)
(1) t=td o
t time after start of exposure to concentration x
=
i td delay time of detector (includes transit time of sample)
=
l to characteristics time constant of detector
=
concentration registered by the detector y
=
actual (constant) concentration
{
x
=
The constants td and to were determined by a statistical analysis of data collected during a test performed by the vendor. HNU Systems. Inc. on the detectors which are now installed at WSES 3.
A fit of the data to equation. above. produces values of 4.06 and 6.84 seconds for t d and top respectively, for the slower of the two instruments. These tests were performed with an instrument pump speed of 6 liters / minute. The pump speed is currently adjusted to 3 1/m however, which, according to the HNU Instruction Manual, doubles the response time.
Adding the transit time through the sampling tube to the newly calculated delay time produces the values of 13.0 and 13.7 seconds for to and to, respectively. The travel time in the duct between the sampling port and the isolation valve is calculated to be 4.7 seconds, while the isolation valves have specified closure times of two seconds following the receipt of the isolation signal.
2.2A 9 l
t
WSES-FSAR UNIT-3 l
1 l
2.2A.2.4 Results and Conclusions A.
Control Room Habitability The results of the analysis show that the highest concentration that could occur in l
the control room by the time the operators were assumed to have donned breathing apparatus (two minutes after the alarm or after odor detection, whichever occurs first) would be 3.7 ppm. This concentration. which would occur at near-calm conditions over four hours after the accident is well below the IDLH concentration of 5 ppm and would thus pose no threat to the operators for the brief time that they would be exposed. In the case of this particular accident scenario moreover, the operators would have been notified by the St. Charles Parish industrial hot line and would have taken protective action long before the vapors reach their site. As;uming that notification would take place within 30 minutes after the accident. the highest concentration to which the operators could be exposed prior to donning breathing apparatus is 2.3 ppm, which is less than one half the IDLH concentration.
According to Regulatory Guide 1.78, the control room would therefore remain habitable under all credible accident conditions.
8.
Plant Overpressure In the unlikely event that the entire contents of all five tanks of acrolein (2.250.000 lbs) exploded simultaneously, and using the conservative estimate that one Ib of acrolein equals six lbi of TNT. this would cause a shock wave at Waterford 3 of about 1.3 psi. This overpressure is less than half than that caused by the design basis explosion: 3 psi peak incident overpressure caused by an explosion of an LPG truck on the road outside the plant (see Response to NRC Ouestion 311.2). The Union Carbide explosion on December 11. 1982 may have caused an overpressure at Waterford 3 as high as 0.05 psi.
REFERENCES FOR APPEN0!X 2.2A 1.
Sittig, M.
Handbook of Toxic and Hazardous Chemicals. Park Ridge. NJ.
l Noyes Data Corp.'-(1980).
2.
N!OSH/ OSHA Pocket Guide to Chemical Hazards. Publication No. 78 210. 1978.
l 3.
Weiss. G. Hazardous Chemicals Data Boot. Park Ridge. NJ Noyes Data Corp. (1980).
I 4
Wing. J. Toxic Vapor Concentrations in: the Control Room Following a Postulated 1
Accidental Release. NUREG 0670..(1979).
5.
Dennis R., Acting Production Manager. Agrico Uncle Sam: Private communication. July
- 12. 1988.
P 2.2A 10
r _ _ _ - _ _-_--_-_ _ __ _ _ _ _ _ _ _ _ _ _
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WSES-FSAR-UNIT-3 TABLE 2.2A-3 WATERFORD STEAM ELECTRIC STATION UNIT 3 ONSITE METEOROLOGICAL DATA:
1972-1978 I
SUMMARY
OF MAXIMUM PERSISTENCE OCCURRENCES Number of Average Direction Hours Speed (MPH)
Date N
13 12.5 10/12/77 NNE 13 18.8 12/09/77 NE 23 7.9 10/20/74 ENE 22 3.4 07/01/77 E
18 12.6 09/01/77 l
ESE 25 11.9 04/11/74'
'SE 20 10.5 10/29/74 l
SSE 19 12.9 04/03/74.
S 20.
14.1 04/04/77 SSW 17 9.2 03/30/77 SW' 14 11.1 02/24/77 WSW 9
2.1 06/11/73 W
'10 13.8 02/22/74 WNW 16 11.8 04/04/73 i
NW.
13 5.7 02/10/73 l -
NNW 17 11.4 11/22/72 1
i I
k